BR122024002976A2 - FALL PROTECTION MONITORING SYSTEM FOR MONITORING A FALL PROTECTION SAFETY APPARATUS AND METHOD FOR CONTROLLING THE OPERATION OF AN AERIAL LIFT - Google Patents

Abstract

“FALL PROTECTION MONITORING SYSTEM FOR MONITORING A FALL PROTECTION SAFETY APPARATUS AND METHOD FOR CONTROLLING OPERATION OF AN AERIAL LIFT” The present invention discloses an aerial lift that is interlocked with a fall protection safety apparatus and may be further interlocked with at least one additional safety apparatus. The aerial lift is equipped with a monitoring system that is configured to detect whether a connector of a safety line of the fall protection apparatus appears to be connected to a safety harness of a user of the aerial lift.

Description

[001]Divided from BR 11 2023 026732 3, filed on 06/22/2022.

Background

[002]Aerial lifts are widely used for a variety of applications. In particular, so-called order pickers are motorized aerial lifts that are widely used for material handling to pick items from vertical stacks, from shelves of various heights, and so on. Summary

[003] In a general summary, there is disclosed herein an aerial lift that is interlocked with a fall protection safety apparatus and may be further interlocked with at least one additional safety apparatus. The aerial lift is equipped with a monitoring system that is configured to detect whether a connector of a safety line of the fall protection safety apparatus appears to be connected to a safety harness of a user of the aerial lift. These and other aspects will become apparent from the detailed description that follows. However, in no event should this summary be construed as limiting the claimed subject matter, whether such subject matter is set forth in the claims of the application as originally filed or in claims that are amended or otherwise set forth later.

Brief description of the drawings

[004]Figure 1 is a side perspective view of an aerial lift, in generic exemplary representation, the aerial lift being an order picker equipped with a monitored fall protection safety device, also shown in generic exemplary representation.

[005]Figure 2 is a side perspective view of another exemplary order picker, shown in a vertically elevated configuration.

[006]Figure 3 is a front view of an exemplary fall protection safety apparatus suitable for use in an aerial lift fall protection system.

[007]Figure 4 is a perspective view of another exemplary fall protection safety apparatus suitable for use in an aerial lift fall protection system.

[008]Figure 5 is a rear view of a fall protection harness suitable for use in an aerial lift fall protection system.

[009] Like reference numerals in the various figures indicate like elements. Some elements may be present in identical or equivalent multiples; in such cases, only one or more representative elements may be represented by a reference numeral, but it is to be understood that such reference numerals apply to all such identical elements. All figures and drawings in this document are not to scale and are selected for the purpose of generally illustrating representative embodiments of the invention. In particular, the dimensions of the various components are shown for illustrative purposes only, and no relationship between the dimensions of the various components should be inferred from the drawings unless so indicated. Although terms such as “first,” “second,” “additional,” “primary,” “secondary,” “tertiary,” and so forth are used in this disclosure, it is to be understood that these terms are used only in their relative senses, unless otherwise specified. Specifically, with respect to the use of such terms to describe various signals described herein, it is emphasized that such terms, or combinations of such terms, do not invoke any temporal order unless specifically noted. Terms such as vertical, up and down, above and below, and so on, have their ordinary meaning in relation to Earth's gravity. The horizontal direction also has its ordinary meaning as any direction perpendicular to the vertical direction.

[010] As used herein as a modifier of a property or attribute, the term “in general,” unless otherwise specifically defined, means that the property or attribute would be readily recognizable by one of ordinary skill in the art without the need for a high degree of approximation (e.g., within ±20% for quantifiable properties). The term “configured to” and similar terms are at least as restrictive as the term “adapted to,” and require an actual design intent to perform the specified function rather than a mere physical capability to perform such function. All references in the present invention to numerical parameters (dimensions, ratios, and so on) should be understood to be calculable (except where otherwise specified) using average values derived from a number of measurements of the parameter.

Detailed description

[011] Disclosed herein are a fall protection safety apparatus 50 and a fall protection monitoring system that can monitor various aspects of the fall protection safety apparatus, as discussed in detail later herein. Such apparatus and systems can be used with aerial lifts, as exemplified by so-called order pickers; an order picker 1 is shown in exemplary generic representation in Figure 1. Order pickers are material handling vehicles that are widely used to pick items from vertical stacks, from shelves of various heights, and so on. As shown in the exemplary embodiment of Figure 1, an order picker is a motorized vehicle that has a generally horizontal platform 2 that supports a human user (operator) of the order picker and that is elevatable to a considerable height, as shown in the exemplary embodiment of Figure 2 (noting that the order picker depicted in Figure 2 differs in several respects from the order picker depicted in Figure 1). The operator typically corresponds to the operator support platform 2, but in some embodiments, the platform 2 may be provided with a seat, bench, or the like. In some embodiments, the order picker includes manual input devices (controls) 4 that allow the operator to operate the order picker, e.g., to direct the order picker, to manually drive the order picker from place to place, to raise and lower the operator support platform, and so on. Such manual input devices may include, for example, a steering wheel or joystick, a forward-reverse control and a speed control, a raise/lower control, a “forward” or “jogging” button for slow movement or fine adjustment of the position of the order picker, and so on. In some embodiments, at least some functions (e.g., the horizontal movements) of the aerial lift may be automatically controlled (e.g., remotely controlled or autonomously controlled) rather than being manually controlled by the operator, as discussed later in this document.

[012] As shown in the exemplary embodiment of Figure 2, an order picker will often comprise a telescopic mast assembly 5 comprising multiple telescopic sections (e.g., two, three, or more) that allow the platform 2 to be raised to a considerable vertical height (e.g., 1, 2, 4, 6, 8, or 10 meters, or more). Order pickers allow an operator on the operator support platform 2 to be positioned so that the operator can manually grasp one or more items and remove them from an elevated location, e.g., from a shelf or stack. In some cases, the operator may place such items on a tray 14 of the general type shown in Figure 2. In some embodiments, an order picker will comprise a set of forks 6 that allow larger items to be removed from an elevated location. An order picker (and an aerial lift in general) thus comprises an operator support platform 2 which is vertically movable between a first “lowered” position in which the platform is adjacent to the ground or floor upon which the order picker is seated (and in which condition the order picker can be moved horizontally, e.g., driven) and a second “raised” (raised) position. The second raised position may, at any given time, be any one of a plurality of raised height positions, e.g., as selected by the operator, to reach a specific item. By definition, a second raised or raised position will be at least 4 inches above the first lowered position.

[013] In many embodiments, an order picker will comprise a console 7, which may feature the controls 4 described above for use by the operator. Often, various electronic components, e.g., control circuitry 17, and so forth, as required to operate the order picker, may be generally situated within the console 7. In many cases, an order picker may comprise a generally vertical wall or panel 8 rising above the console and supporting a generally horizontal overhead bulkhead (ceiling) 9. Descriptive terms such as wall, panel, ceiling, and so forth are not intended to limit such entities to purely continuous (e.g., unbroken or uninterrupted) structures. Any such entity may, for example, take the form of, e.g., one, two, or more beams, columns, or the like (as in the exemplary design of Figure 2), with at least some empty space provided, e.g., so that the user may access a tray 14 if necessary. Typically, the console 7, the panel 8, and the overhead bulkhead 9 are in fixed relationship with the operator support platform 2, such that these components move vertically in unison with the platform 2. In many embodiments, at least portions of the panel 8 and/or the bulkhead 9 may be transparent to improve the operator's visibility of the horizontal and vertical surroundings. For example, in many embodiments, at least a portion of the panel 8 may comprise a grid or mesh of widely spaced wires, as shown in the exemplary embodiment of Figure 1.

Additional positive signs

[014] As noted above, an aerial lift, e.g., an order picker, will comprise a fall protection safety apparatus 50 and a fall protection monitoring system that monitors the fall protection safety apparatus. The fall protection monitoring system will be configured to directly or indirectly send at least a first positive signal to the control circuit of the aerial lift so that the control circuit enables certain functions of the order picker as discussed in detail later in this document. Various components of the fall protection monitoring system may be installed on or in one or more components of the fall protection safety apparatus and/or may be installed on the aerial lift itself, or integrated with the aerial lift, as discussed in detail later in this document.

[015] The aerial lift will comprise at least one safety device in addition to the fall protection safety device. Any such safety device will be referred to as an “additional” safety device and will be monitored so that an “additional” positive signal can be sent to the control circuit of the aerial lift. Typically, the components of any additional safety device, and systems for monitoring the status of any such additional safety device, will be installed within or on the structure of the order picker itself, and will generally be powered by the order picker rather than relying on a separate power source.

[016] An additional safety device that may be present is an operator presence control (OPC) switch 15, as shown in the exemplary embodiment of Figures 1 and 2. An OPC switch is a switch that must be engaged for at least some functions of the order picker to become activated and must be maintained in the engaged condition for those functions of the order picker to remain activated. In some embodiments, the order picker will not move vertically (but may still be capable of moving horizontally) unless the OPC is engaged. In some embodiments, an order picker will not move horizontally or move vertically unless the OPC switch is engaged (so that the OPC switch is in a “ready” position). This enabling and disabling of various order picker functions will be controlled by the order picker control circuit 17 based on signals received from the OPC switch.

[017] An OPC switch (sometimes called a deadman switch, surveillance control switch, or driver presence sensor) is intended to ensure that the order picker operator is present (e.g., standing on platform 2) and is in active control of the order picker rather than being, for example, incapacitated. When the OPC switch is in a ready position indicative of active control of the aerial lift by the lift user (operator), the OPC switch will send an additional positive (ready) signal to the order picker control circuit; based on this additional positive signal, the order picker control circuit will keep certain functions of the order picker enabled. In the absence of such an additional positive signal, the control circuit will disable at least some functions of the order picker. An additional positive signal from an OPC switch will be referred to as a primary additional positive signal to distinguish it from other additional positive signals discussed below. In some embodiments, the OPC switch may send such a signal wirelessly; however, in some embodiments, it may be convenient for the OPC key to have a wired connection to the control circuit 17 for such purposes.

[018] In some embodiments, an OPC switch 15 may take the form of one or more pedals that can be contacted by the operator's foot, for example, to move the pedal from an up disengaged position to a down engaged position. The pedal is biased toward the up disengaged position, such position being indicative that no active control of the order picker by a human operator is occurring. The down position is indicative that active control is present and will cause the primary additional positive signal to be sent to the order picker control circuit indicating that the OPC switch is in a ready condition indicative of active control by a human user. The term “pedal” is used generally to denote any item that is suitably contactable, e.g., depressible, by the operator's foot. Such an item may be, for example, a “button” mounted directly to the floor of platform 2 (as in Figures 1 and 2) or may, for example, extend rearward from a lower portion of console 7 in the general manner of a piano pedal. Or such an item may be positioned within a recess in the lower portion of console 7 such that the operator inserts his or her foot slightly into the recess to reach the OPC switch. In some embodiments, an OPC switch may be relatively large (or, two OPC pedals or buttons may be provided) so that the operator may shift its position and/or may alternate which foot is used to press the item, in order to improve operator comfort. In some embodiments (e.g., where an operator of an aerial lift may occasionally need to face different directions), multiple pedals (e.g., two or three) may be provided, e.g., spaced in an arc around the operator's position, with at least one (in some designs, two) pedal that needs to be contacted by a foot of the operator for an additional primary positive signal to be emitted.

[019] In other embodiments, an OPC switch may take the form of, for example, a limb that needs to be gripped or compressed by a user's hand to be placed in an engaged position. Accordingly, it will be understood that an OPC switch may take any suitable physical form and may be in any suitable location. Whatever the form, in many embodiments, any OPC switch will have a default position (and will often be biased toward that default position) that is a disengaged position and will therefore require an operator to actively set the OPC switch to an engaged position.

[020] In some embodiments, an OPC key may take the form of, for example, one or more sensors that confirm that the operator's foot has been placed in a specific location that confirms that the operator is present and in active control of the order picker, without the operator necessarily needing to apply pressure with his or her foot. It will be appreciated, therefore, that an OPC “key” need not necessarily take the form of a physical key. Indeed, in some embodiments, one or more cameras and associated image processing circuitry may be configured to serve as an OPC “key,” as discussed in detail later in this document. Thus, in summary, an OPC “key” may take the form of any single item or set of items, functional system, and so forth, that individually or collectively verify that the operator is in active control of the order picker.

[021] Another additional safety apparatus of an order picker that may be present is a safety door apparatus. As shown in the exemplary embodiment of Figures 1 and 2, such a safety door apparatus may comprise at least one safety door. In many embodiments, the safety door apparatus will comprise first and second (e.g., left and right, from the perspective of Figure 1) doors 11 and 12, as shown in the exemplary embodiment of Figures 1 and 2. In some embodiments, at least one of these doors will be movable; often, both doors will be movable, between a stowed position and a protective (ready) position (such doors are often referred to as retractable side doors). In a protective position, a door will be generally disposed above a side edge (left or right) of the operator support platform 2 with the two doors combining to flank laterally, e.g. to partially enclose, platform 2, as evident in Figure 2. In a stowed position, a door will be in a non-protective position (e.g., pivotally moved upward as with door 11 of Figure 1) which, for example, allows an operator to step onto platform 2 while the order picker is in its first lowered position.

[022] The term “door” is used to encompass generally any member, beam, rail or set of such members that can operate in the manner described above. In some embodiments, one or both of the doors may be, for example, pivotable about a pivot connection with the order picker 1, such that the door can be opened (e.g., raised) into a stowed position that allows an operator to enter the platform 2 and can then be closed (e.g., lowered) into a protective position. In some embodiments, the doors may be independently operable such that one may be in a stowed position while the other is in a protective position (e.g., as in the exemplary embodiment of Figure 1); in other embodiments, the doors may operate in unison. In some embodiments, one or both of the doors may be opened and closed manually, for example, by means of controls located on the console 7 of the order picker; In some embodiments, one or both doors may be configured to automatically close or open under certain conditions.

[023] The arrangements described above are exemplary, and many arrangements of such doors are possible. For example, some such doors, or at least a portion thereof, may pivotally move upward, rather than downward, into a protective (closed) position. Some doors may have one or more portions that move in a sliding rather than pivotally manner. In some embodiments, a door may comprise one or more vertical members, columns, or panels (e.g., as in the exemplary arrangement of Figure 2). In some embodiments, one or more such vertical members may, for example, swing downward from a top track of the door (e.g., to contact platform 2) as the door moves into a closed position; or such a member may be in fixed relationship with a track of the door. Any such arrangement of closed doors may border, e.g., may at least partially enclose, the lateral sides of the operator support platform 2. In some embodiments, an additional door may be provided at or near the rear of the platform 2 (e.g., at a location generally opposite the console 7). However, in some embodiments, that end of the platform 2 may be left relatively open so that the operator can easily reach and grasp an item that is to be removed from an elevated location.

[024] A safety door apparatus may be configured with a detection system that signals the order picker control circuit 17 whether each door that is movable is in its retracted position or in its protective position. In particular, when all such movable doors are in a protective (ready) position, the safety door apparatus detection system will output at least one additional positive (ready) signal indicating that the safety door apparatus is in a protective condition. This additional positive signal (or signals) will be referred to as a “secondary” additional positive signal to distinguish it from the additional positive signal from the OPC switch, which has been referred to as the “primary” additional positive signal (noting again that such terms do not imply that the signals need to be sent, or received, in any particular temporal order).

[025] Thus, in some embodiments, in order for the order picker control circuit 17 to enable certain functions of the order picker and keep them enabled, the control circuit will need to receive an additional secondary positive signal from the security door apparatus, for example, in addition to receiving an additional primary positive signal from the OPC switch, as described above. In the absence of such an additional secondary positive signal, the control circuit may disable at least some functions of the order picker. In some embodiments, the security door apparatus detection system may send such a signal to the control circuit wirelessly; however, in some embodiments, the security door apparatus detection system may have a wired connection to the order picker control circuit for such purposes.

[026] Thus, in some embodiments, an order picker may have two safety apparatuses (e.g., an OPC switch and a safety door apparatus) in addition to the fall protection safety apparatus described herein. In such embodiments, the order picker control circuit may need to receive at least three positive signals (i.e., at least a first positive signal from the fall protection monitoring system, an additional primary positive signal from the OPC switch, and an additional secondary positive signal from the safety door detection system) to enable certain functions of the order picker.

[027] In some embodiments, the order picker may have one or more additional security apparatuses installed therein and, as such, may require one or more additional positive signals from the additional security apparatus to enable the functions of the order picker. For example, such an additional security apparatus may be an operator authentication device 16 that (e.g., by scanning an RFID tag, bar code, NFC code, or QR code, e.g., a person's badge) may confirm that the person is trained and authorized to operate the order picker. In other embodiments, such an operator authentication device may take the form of a facial recognition system, an iris recognition system, a voice recognition system, or a keypad or other interface through which the person may be required to enter a special code or password. Proper authentication, however, may result in an additional, tertiary positive signal that is sent to the control circuitry of the order picker. If the order picker is equipped with an additional safety device, one or more additional positive signals, for example a quaternary additional positive signal, can be sent in a similar manner to the control circuit.

[028] In various embodiments, any or all of an additional primary, secondary, tertiary, and quaternary positive signal may be sent to the control circuit of the aerial lift, in addition to the at least one “first” positive signal that will be sent by the fall protection monitoring system and which is described in detail later in this document. Any individual additional positive signal may be used in the absence of any other additional positive signal; furthermore, any subset or combination of additional positive signals may be used. It is emphasized again that terms such as primary, secondary, tertiary, and so forth are used for convenience of description only and do not necessarily imply any specific hierarchy or temporal order. For example, in some embodiments, an order picker interlock system may rely on an additional tertiary positive signal from an operator authentication device, regardless of whether the interlock system also relies on an additional secondary positive signal from a safety door detection system. Although discussions of the present invention relate primarily to interlocking the vertical movement function of order pickers, it will be understood that an order picker may be configured so that various additional positive signals or combinations thereof may cause different functions to be interlocked. For example, in response to an additional positive signal, the horizontal movement function of the order picker may be disabled; in response to a different additional positive signal, a maximum horizontal speed of the order picker may be imposed; in response to a different additional positive signal, the order picker may be completely stopped, and so on.

[029] As noted, any of these additional positive signals may be sent to the order picker control circuit wirelessly or via one or more wired connections. Since many of these signals may originate from an entity that is an installed component or subsystem of the order picker itself (e.g., an OPC switch, a security door detection system, etc.), in some embodiments, the signals may be sent to the order picker control circuit via a wired connection. However, in some embodiments, any signal may be transmitted wirelessly. In some cases, any or all of these signals may be sent continuously. However, this need not necessarily be the case; in some cases, a primary, secondary, tertiary signal, and so on, may be sent intermittently or periodically, as long as the transmission frequency is high enough that a change in the state of the security apparatus is communicated to the control circuit quickly enough.

Fall protection device

[030] An aerial lift, e.g., an order picker 1, will be provided with a monitored fall protection safety apparatus 50, as shown in the exemplary embodiment of Figures 3 and 4. Such a fall protection apparatus 50 may be used as part of a fall protection system that includes a fall protection safety harness 40 (as shown in the exemplary embodiment of Figure 5) configured to be worn by a human operator of the aerial lift. The fall protection safety apparatus 50 will comprise a safety line 52 (which may take the form of, for example, a metal cable, a DYNEEMA strap, and so on), a distal end of the safety line being equipped with a connector 30 configured to be connected to the harness 40. (Other components may also be present, as will be well understood by those skilled in the art.)

[031] A connector 30 may be referred to herein by the generic terminology of a “hook” or “locking hook”; however, it will be understood that some such connectors are often referred to as carabiners, and there is not necessarily a firm dividing line between the two. Many such hooks and carabiners (as illustrated in more detail in the exemplary embodiment of Figures 3 and 4) will comprise a main body 31 and a movable gate 32, and will thus be referred to as a locking hook. In at least some embodiments, any such connector will be compliant with the ANSI Z359.012-2019 standard. In some embodiments, a connector may be a dual-action connector (i.e., with a gate that requires at least two consecutive, different actions to open). One category of dual-action connectors are so-called twist-lock hooks and carabiners of the general type exemplified by the product available from 3M Fall Protection under the trade designation KJ5108 HOOK CONNECTOR and various connectors available from 3M Fall Protection under the trade designation SAFLOK. In such connectors, a locking mechanism 33 of the port 32 of the connector 30 must be twisted (e.g., at least a quarter turn, around an axis of rotation aligned with the long axis of the port) to unlock the port so that the port can then be opened. In various embodiments, a locking mechanism 33 may be a collar fitted to a portion of the port (as in the exemplary arrangement of Figure 4); or the entire port may be twistable. Some connectors (e.g., products available from 3M Fall Protection under part numbers 2000300 and 2000301) may be triple-acting connectors in which the collar and/or door must be moved slightly along its long axis, in addition to being rotated, to allow the door to be opened. Another category of double-acting connectors are so-called snap-fit hooks (or latching snap hooks) in which a latching mechanism must be moved (e.g., pressed in or compressed) before the door of the hook can be opened. Such connectors include those available from 3M Fall Protection under part numbers 2007153 and 9510057. All such items will be considered connectors as defined herein and may be referred to generically as latching hooks.

[032] In many embodiments, a connector 30 of a lifeline 52 may be configured to be connected to a fall protection safety harness 40 by being attached to a D-ring that is non-removably mounted to the harness. In specific embodiments, the connector may be attached to a dorsal D-ring 41 of the general type illustrated in Figure 5. It is emphasized that the term “D-ring” generally encompasses any item that is attached to a fall protection harness and that is purposefully configured to have a connector of a lifeline attached thereto. Such an item need not necessarily exhibit any particular shape; in particular, such an item need not be strictly D-shaped. In some embodiments, a connector of a lifeline (and the associated “D-ring” of a harness) may be a matching pair of connectors (e.g., one on a lifeline and one on a harness; or on the ends of first and second straps, lines, or the like) that are specifically configured to be compatible or otherwise engageable with each other, but are not intended to be compatible with other types of connectors. In some embodiments, such connectors include modular connectors of the general type described in the 3M DBI-Sala 2017 Full Line Fall Protection Catalog as being provided as components of modular straps, such as, for example, the EZ-STOP MODULAR STRAP. Such connectors may, for example, comprise a female connector with a generally T-shaped slot configured to accept a generally T-shaped bar of the other male connector. In many embodiments, such connectors may be lockable when engaged such that they cannot be disengaged from one another without prior intentional manipulation that places them in an unlocked condition in which they can be disengaged from one another. In some embodiments, such connectors include so-called general type quick connectors provided as a component of, e.g., the 3M DBI-SALA NANO-LOK self-retracting lifeline, general type quick connect buckles provided as a component of, e.g., the 3M DBI-SALA EXOFIT STRATA harness, and the like.

[033] In many embodiments, a fall protection safety apparatus 50 that is monitored as described herein may be a so-called self-retracting lifeline (SRL), as shown in the exemplary embodiment of Figures 3-4. Those skilled in the art will understand that a self-retracting lifeline comprises a load-bearing lifeline (“lifeline”) 52 that can be unwound from a housing 51 that can be attached to an anchorage 13 located, for example, on an overhead bulkhead or (“ceiling”) 9 of the aerial lift. A distal end of the safety line 52 is connectable, for example, via a connector (e.g., a locked hook) 30, to a D-ring 41 of a harness 40. In some embodiments, the connector 30 may be connected to the distal end of the safety line 52 by a swivel connection (e.g., a swivel) such that the connector 30 can rotate as required by the operator's movements without causing the safety line 52 to become twisted.

[034] The SRL cabinet 51 comprises a spool (drum) 53 (generally indicated in Figure 3) that is pivotally connected to the cabinet 51, with a proximal end of the safety line 52 being attached to the spool 53. The safety line 52 may be unwound from the spool 53 and thus extended from the cabinet 51 to follow a user as the user moves, with the spool 53 being biased such that the spool retracts the safety line 52 back into the cabinet 51 and rewinds it onto the spool 53 as the user moves toward the cabinet 51. In some embodiments, at least a lower portion of the cabinet 51 of an SRL may be covered by a soft covering; for example, in some embodiments, substantially the entire enclosure 51 may be contained, for example, within an additional padded canvas cover comprising a lower opening to allow the lifeline 52 to pass therethrough and an upper opening to allow the enclosure to be attached to an anchorage. The term anchorage as applied to an aerial lift denotes any item that is attached (directly or indirectly) to the aerial lift such that a connector of a fall protection lifeline can be attached thereto, as well as any component of the aerial lift (e.g., a metal strut or beam) that is itself suitable for attaching a connector of a lifeline thereto.

[035] An SRL (e.g., cabinet 51 and reel 53 thereof) will typically include a brake, e.g., comprising centrifugally activated pawls that act in cooperation with a ratchet ring. Such a brake will activate in the event of a user falling (e.g., upon rapid unwinding of safety line 52 from reel 53) to safely bring the user to a stop. In some embodiments, a ratchet ring may be fixed in position (e.g., attached to cabinet 51). In other embodiments, an SRL may comprise a ratchet ring that can rotate at least somewhat if a centrifugally activated pawl contacts a tooth of the ratchet ring; in such a case, the brake will often include one or more pads of friction material that gradually stop the rotation of the ratchet ring.

[036] In some embodiments, an SRL may comprise a lifeline 52 that is equipped with an energy absorber 35, as shown in the exemplary embodiment of Figure 4. In some embodiments, an energy absorber 35 may take the form of a so-called shock pack or tear strip. Such energy absorbers often rely on two or more line segments, e.g., webbing, that are secured (e.g., by stitching) to one another. Such segments may be folded in a concertina (z-folded) arrangement, with the segments and fasteners being arranged such that, in response to sufficient force (e.g., in the event of a fall), the fasteners will yield so that the segments separate (e.g., “unzip” and/or uncoil) from one another in a manner that absorbs energy to safely bring the user to a more gradual stop than would otherwise occur in the absence of the energy absorber. Such energy absorbers are often used on SRLs that have a fixed ratchet ring and that do not include the friction material pads described above; however, an energy absorber can be used on an SRL of any design.

[037] Fall protection apparatus such as self-retracting lifelines and components and operation thereof are described in various aspects in US Patents 7843349, 8256574, 8430206, 8430207 and 9488235. In some embodiments, an SRL may be a so-called “personal” SRL that is used in a manner slightly different than that described above. However, the arrangements disclosed herein may be used with such an SRL, as discussed in detail later in this document. In some embodiments, a self-retracting lifeline will meet the requirements of ANSI Z359.14-2014. Any fall protection apparatus may be configured to allow an operator of an aerial lift (e.g., an order picker) to perform actions as required while the aerial lift’s operator support platform is in an elevated condition. For example, the operator will be able to operate the controls of the aerial lift to reach and retrieve an item from a raised shelf near the elevated lift platform, and so on. A fall protection device in the form of an SRL may additionally enable the operator to move short distances as needed while remaining connected to the safety line (e.g., momentarily stepping off the aerial lift platform when the aerial lift is in its “down” position), to the extent that such actions are permitted by the work facility in which the aerial lift is used.

Fall protection monitoring system

[038] An aerial lift as disclosed herein will comprise a fall protection monitoring system configured to monitor one or more aspects of the fall protection safety apparatus 50. This monitoring system will be configured at least to determine at least whether the connector 30 of the safety line 52 of the fall protection safety apparatus appears to be connected to a fall protection safety harness 40 (e.g., to a D-ring 41 of the safety harness) worn by a user of the aerial lift 1 with which the fall protection apparatus 50 is used. The fall protection safety apparatus 50 and the fall protection safety harness 40 may thus be combined to form a fall protection system. However, these items need not be together in the aerial lift at all times; for example, a fall protection device such as an SRL may be on the aerial lift and remain with the aerial lift, while a safety harness may be worn by the operator even while the operator is disconnected from the SRL and is away from the aerial lift.

Interlocking and first positive signs

[039] A fall protection monitoring system for a fall protection safety apparatus may, in some embodiments, comprise at least one sensor module and at least one base unit, as discussed in detail later in this document. Any fall protection monitoring system will be configured such that if the monitoring system determines that the connector appears to be connected to the safety harness, the fall protection monitoring system will output at least one positive signal that may be received, directly or indirectly, by the control circuitry of the aerial lift. A positive signal that is output by the fall protection monitoring system of the fall protection apparatus indicating that the connector appears to be connected to the safety harness (and thus, at least in this specific respect, the fall protection apparatus appears to be in a ready condition) will be referred to as a “first” positive signal to distinguish it from the “additional” positive signals described above (e.g., a primary additional positive signal output by an aerial lift OPC switch, a secondary additional positive signal output by an aerial lift safety door apparatus, a tertiary additional positive signal output by an aerial lift authorization safety apparatus, and so on).

[040] As disclosed herein, an aerial lift 1 is interlocked with the fall protection safety apparatus 50 and with at least one additional safety apparatus of the aerial lift. This means that for at least the vertical movement function of the aerial lift to be enabled, the control circuit of the aerial lift needs to receive at least a first positive signal from the fall protection monitoring system indicating that at least the safety line connector appears to be connected to the user's safety harness (i.e., that the fall protection apparatus is in a ready condition); and the control circuit of the aerial lift needs to receive at least one additional positive signal from at least one additional safety apparatus of the aerial lift indicating that the at least one additional safety apparatus is in a ready condition. The control circuit must continue to receive the at least one first positive signal, and the at least one additional positive signal, so that at least the vertical movement function of the aerial lift remains enabled.

[041] In some embodiments, the only additional positive signal that the control circuit needs to receive to enable at least the vertical movement function of the aerial lift is a signal from the OPC switch. In other embodiments, the control circuit may need to receive a primary additional positive signal from the OPC switch and receive a secondary additional positive signal from a safety door apparatus to enable at least the vertical movement function. In still other embodiments, the control circuit may need to receive one or both of these additional positive signals along with a tertiary additional positive signal from an operator authentication device to enable at least the vertical movement function. Any combination of these additional positive signals (totaling one, two, three, four, or more additional positive signals) may be used, with the exception that at least a first positive signal, from the monitoring system monitoring the fall protection safety apparatus, will always be required along with any additional positive signals that are required.

[042] In some embodiments, a fall protection monitoring system may be configured to output a negative signal indicating that the fall protection apparatus is not in a condition in which the aerial lift may be raised, for example, if the connector of the apparatus has been detected as not being connected to the operator's harness. Such a negative signal, when received by the order picker control circuit, will cause the control circuit to disable at least the vertical movement function of the order picker. However, in many embodiments, the interlocking arrangements disclosed herein may operate based solely on the presence or absence of one or more first positive signals rather than on the output of any explicitly negative signal. That is, in some embodiments, the aerial lift control circuit may take action (or, more strictly speaking, may prevent action, such as raising from occurring) based merely on the absence of a first positive signal. In other words, rather than outputting a negative signal if the fall protection apparatus connector appears to no longer be connected to the aerial lift user's harness, the fall protection monitoring system may simply cease outputting a first positive signal or positive signals, as later disclosures of the present invention will become apparent.

[043] As disclosed herein, the fall protection monitoring system will need to transmit at least a first positive signal to the aerial lift in order for the vertical movement function of the aerial lift to be enabled. After the vertical movement function becomes enabled, the fall protection monitoring system will need to continue to transmit the at least a first positive signal (either intermittently at a sufficiently high frequency or continuously), and the aerial lift will need to continue to receive the at least a first positive signal in order to maintain the vertical movement function enabled. The herein described interlocking of an aerial lift with a fall protection monitoring system therefore applies not only to the start-up and initial movement and use of the aerial lift, but will also apply to subsequent operation of the aerial lift while it is to continue.

[044] In some embodiments, an aerial lift may be configured such that the vertical movement function of the aerial lift is not enabled in the absence of the positive signals discussed above, in a substantially absolute manner. This means that elevation of the operator support platform cannot be accomplished from a first lowered position (which is typically the lowest position to which the platform can be lowered and is the position that allows the operator to step onto the platform) to a second aforementioned elevated position, in the absence of a first positive signal from the fall protection monitoring system. In other words, such an aerial lift will be substantially incapable of ascending any significant amount unless the fall protection monitoring system reports that the operator appears to be connected to the fall protection apparatus.

[045] However, in some embodiments, it may be permissible, or even advantageous, for an aerial lift to operate in a mode in which a predetermined limited amount of vertical elevation is permitted in the absence of the aforementioned positive signal(s). In other words, in some embodiments, it may be possible to raise the operator support platform to a maximum height of, for example, 1.0, 1.5, 2.0, 3.0, 3.5, or 3.9 feet (e.g., less than or equal to 4.0 feet) relative to the first lowered position even if the fall protection monitoring system has not reported that the operator appears to be connected to the fall protection apparatus. Such a mode may allow at least some limited use of the aerial lift without the operator being connected to the fall protection apparatus. In some embodiments, this maximum height may be predefined and unchangeable for a given order picker; in other embodiments, such maximum height may be set by an authorized person at a facility in which the order picker is used.

[046] Accordingly, it is emphasized that the concept of enabling a vertical movement function of an aerial lift upon receipt of at least a first positive signal, as disclosed herein, does not merely encompass cases in which substantially no vertical elevation is possible in the absence of the first positive signal(s). Rather, this terminology also encompasses cases in which enabling the vertical movement function allows vertical elevation of the operator support platform beyond a predetermined limited height (e.g., 1 to 4 feet) that is permitted even in the absence of the positive signals. However, it is emphasized that an order picker (and any aerial lift in general) may only be used in this manner, and to any defined maximum height, if permitted by all applicable laws, rules, codes, standards, etc., in the facility and jurisdiction in which the order picker is used.

[047] In some embodiments, the condition that the vertical movement function of the aerial lift is not enabled will mean that the aerial lift is not capable of ascending or descending. However, in some embodiments, the condition in which the vertical movement function of the aerial lift is not enabled will only mean that the lift is not capable of ascending. In such embodiments, the aerial lift will be capable of descending even in the absence of the first positive signal(s) that is/are required for ascent to be enabled. In at least some embodiments, this mode of operation (e.g., in which descent is always permitted regardless of signals received or not received from the fall protection monitoring system) may be preferred. In view of this, it is stipulated that references herein to vertical movement, vertical movement function, and similar terminology refer to at least one elevation and, optionally, but not necessarily, one descent.

[048] In some embodiments, only the vertical movement function of the aerial lift may be enabled and disabled in accordance with the aerial lift control circuit receiving, or not receiving, the first positive signal(s) from the fall protection monitoring system. That is, in some embodiments, the aerial lift may still be capable of moving horizontally independently of signals emitted by the fall protection monitoring system (and/or by at least one additional safety apparatus). In other embodiments, both the vertical movement function and the horizontal movement function of the aerial lift may be enabled and disabled in the manner described above. In such embodiments, the aerial lift may be incapable of moving, in either direction, unless the first positive signal(s) is received by the aerial lift control circuit. In many embodiments, the state of one or more of the additional safety devices described above may have an effect on the operation of the aerial lift that, in some circumstances, is independent of signals emitted by the fall protection monitoring system. Thus, for example, even though an aerial lift may be capable of moving horizontally in the absence of a first positive signal from the fall protection monitoring system, the aerial lift may nevertheless need to receive, for example, a tertiary positive signal confirming that a person is authorized to use the aerial lift in order for the aerial lift to move horizontally.

[049] As noted previously in the present invention, an aerial lift (e.g., an order picker) will typically comprise a console 7 that contains a number of input devices 4 that are contacted (e.g., gripped) by a user of the aerial lift and are manipulated to manually control the operation (e.g., vertical and horizontal movement) of the aerial lift. Such manual control input devices may take the form of, for example, one or more wheels, levers, joysticks, hooks, grips, buttons, and so forth, and may be manipulated by, for example, pushing, pulling, turning, twisting, tilting, touching, and so forth. When a vertical movement function of the aerial lift is disabled as described above, the specific manual control input device or devices that are normally manipulated to cause the lift to perform vertical movement will be blocked from being unresponsive when manipulated by the user in an attempt to input a command for movement. When the vertical movement function is enabled, the device or devices will be responsive to attempted input by the user. Similarly, if an aerial lift is configured so that a horizontal motion function of the aerial lift is disabled, in addition to disabling the vertical motion function, the manual control input device or devices that are normally manipulated to cause the lift to perform horizontal motion will be locked so that they are unresponsive. When the horizontal motion function is enabled, the device or devices will be responsive.

[050] In the case of an aerial lift (e.g., an order picker) where at least some of the movements and functions are automatically and/or remotely controlled, the interlocking disclosed herein may apply to actions taken, or disallowed from being taken, by the aerial lift when under automatic control, as discussed in detail later in this document. In such a case, the interlocking may also include measures to prevent a user from manipulating manual controls in a manner that would overcome automatic control. In other words, if an interlocked and automatically controlled aerial lift is, for example, prevented from lifting, the interlocking arrangement may include disabling manual controls so that the operator of the aerial lift cannot override the prohibition against lifting the aerial lift by applying manual control.

[051] In various embodiments, communications between the fall protection monitoring system (e.g., a base unit thereof) and the control circuit of the aerial lift may be one-way or two-way (such communication may also be direct or indirect; and via wire or wireless means, all as discussed in detail later in this document). If the communication is one-way, it will flow from the monitoring system to the aerial lift. That is, in such embodiments, the control circuit of the aerial lift will be configured to receive and act upon information received from the base unit of the fall protection monitoring system; however, the base unit of the monitoring system will not be configured to receive and act upon information received from the control circuit of the lift. If the communication is two-way, the control circuit will have the above functionality, and the base unit will be configured to receive, and act upon, information received from the control circuit. In some embodiments, a base unit may be configured with a galvanically isolated interface through which it will receive a signal (e.g., in the form of a constant voltage) from the control circuit and then return the signal to the control circuit, both of which are accomplished while maintaining galvanic isolation between the control circuit and the base unit as described in detail later in this document. Such an arrangement, by itself, will not be considered to necessarily have two-way communication as described above.

[052] In some embodiments, the two-way communication may provide that the control circuit of the aerial lift may send the fall protection monitoring system information regarding the vertical elevation of the aerial lift operator support platform. In other words, the control circuit may record the height to which the platform has been elevated and may transmit this information to the fall protection monitoring system, which may be useful in some circumstances. For example, the fall protection monitoring system may be configured such that if the fall protection monitoring system determines that the lifeline connector appears to have become disconnected from the user's safety harness while the operator support platform is in a vertically elevated condition, the fall protection monitoring system may transmit a “disengaged while elevated” warning notification. (The general topic of notifications, which may be transmitted by a fall protection monitoring system and/or by the control circuit of an aerial lift, is discussed in detail later in this document.) Such a warning notification may take any suitable form and may have a specific form that distinguishes it from other notifications. For example, compared to some other notifications, it may comprise a louder or more shrill audible signal, a visual signal that is brighter, flashes more rapidly, and/or is a different color, a particularly noticeable haptic sensation, and so on. If the warning notification includes verbiage, it may take any suitable form (and need not necessarily take the form of the exact phrase “disengaged while elevated”).

[053] A platform elevation height that is required to trigger such a warning notification may be any suitable value, for example, 1.0, 2.0, 3.0, 4.0, 5.0, or 6.0 feet or greater (it being noted that these and other heights disclosed herein are relative to the first lowered position of the platform). Such a height may be preset at the manufacture of the aerial lift and/or fall protection apparatus (and thus may be unchangeable); or, in some embodiments, may be programmable or customizable by an authorized person at the facility in which the aerial lift is used.

[054] As disclosed herein, an aerial lift may be configured such that the absence or cessation of at least a first positive signal from a fall protection monitoring system will cause at least the vertical movement function (and in some cases the horizontal movement function as well) of the aerial lift to be disabled. In some embodiments, it may be useful to enable a privileged mode of operation in which, for example, restrictions on horizontal movement may be overridden, but in which restrictions on vertical movement may be maintained. Such a mode may be useful in situations in which the ability of the aerial lift to propel itself horizontally under its own power may be advantageous (e.g., so that the aerial lift does not have to be lifted and transported by a forklift), but in which it is not necessary or desirable to elevate the aerial lift. Such a situation may arise, for example, when an aerial lift is initially being rolled onto the production line, is being automatically transported to an end-use facility after being unloaded from a delivery truck, is undergoing maintenance, and so forth. (It is therefore anticipated that the need for such a mode of operation will only occur occasionally.)

[055] To prepare for such eventualities, in some embodiments, the control circuit of the aerial lift may be configured such that one or more predetermined conditions are met, and the control circuit will permit a privileged mode of operation. When such a mode is entered, at least the one or more manual control input devices that control the horizontal movement of the aerial lift are activated to a state in which they are responsive to control inputs regardless of any first positive signal being issued by the fall protection system. Typically, the restraints applied by the aerial lift's additional safety apparatus will remain unchanged; for example, the aerial lift will not be capable of being moved horizontally unless the OPC switch is engaged and the safety door apparatus is in a ready condition.

[056] A predetermined condition that must be satisfied to enable such a mode of operation may be anything that confirms that a specific user of a specific aerial lift is authorized to operate the aerial lift in a privileged mode. Such a predetermined condition may take the form of, for example, a user entering a special password or code on a keypad of the aerial lift or a base unit of the fall protection monitoring system, it may take the form of a user having a special badge that, for example, when read by the aerial lift or base unit, authorizes the privileged mode, and so on. Any such general arrangement may be used. In some such embodiments, during any privileged mode, one or more notifications may be transmitted (e.g., in the form of special audible or visual signals) signifying that the aerial lift is currently being operated in the privileged mode.

[057] In a special case of this arrangement, in some embodiments, an aerial lift may be configured so that, under certain conditions, it may be operated in a special privilege mode in which horizontal and vertical upward movements of the order picker are permitted regardless of any first positive signal being emitted by the fall protection system. It is envisaged that operation in such a mode would likely be permitted only under very specific circumstances and, for example, would be subject to enhanced operator identification and/or authorization procedures.

[058] In common use of many aerial lifts (e.g., order pickers), only a single user/operator will be present, e.g., standing on the operator support platform. However, in some embodiments, multiple (e.g., two or more) persons may be present. This may occur, for example, when a person is being trained to operate an aerial lift or if the aerial lift is being used for a procedure involving two or more persons. To allow for such eventualities, in some embodiments, an aerial lift may comprise a “multiple user” mode of operation in which the control circuit needs to receive (at least) two first positive signals, one confirming that a connector is connected to the harness of a first user (e.g., a “trainer”) and another confirming that a second, separate connector is connected to the harness of a second user (e.g., a “trainee”) to enable the vertical movement function of the aerial lift.

[059] In some embodiments, a chosen aerial lift may be equipped with two fall protection safety devices that are permanently located on the aerial lift, for example, to serve as a “training” lift. In some embodiments, a “mobile” fall protection safety device may be configured so that it may be installed for a desired time on an aerial lift that already has a “resident” fall protection device. In various embodiments, a fall protection monitoring system may be configured so that it can monitor such a fall protection device; or two separate monitoring systems may be used. Whatever the arrangement, the aerial lift will be configured so that when the aerial lift is in a “multiple user” mode, the control circuit of the aerial lift must receive at least a first positive signal indicating that the connector of the first fall protection device appears to be connected to the harness of a first user, and must also receive another positive signal indicating that the connector of the second fall protection device appears to be connected to the harness of a second user. Only after both of the first positive signals have been received (along with any additional positive signals of the types discussed here previously) will the vertical movement function of the aerial lift be enabled.

[060] In some cases, an aerial lift may be able to detect (e.g., through a camera-based detection system as described later) that two (or more) people are present on the operator support platform of an aerial lift and provide this information to the aerial lift's operating circuit such that the aerial lift will consequently enter a “multi-user” mode. An aerial lift may also be configured such that a user may input a command to the aerial lift to enter a multiple-user mode.

Remote/automatic control and telemetry

[061] Although discussions thus far have focused primarily on manual control of an aerial lift (e.g., an order picker), in some embodiments, the arrangements disclosed herein may be used with an aerial lift whose movements are guided at least in part by automatic and/or remotely applied control rather than manual inputs from a human user. Such an aerial lift may, for example, follow designated trajectories in a warehouse, with the horizontal movements of the aerial lift being directed by a central station that plans and directs the horizontal travel of many aerial lifts. Such guided horizontal movements of a lift may be facilitated by an automatic control system comprising, for example, any suitable combination of tracking indicia (e.g., RFID tags) provided on the warehouse floor; guide wires incorporated into the warehouse floor; physical tracks mounted on the floor followed by guide cylinders on the aerial lift; cameras operating in conjunction with computer vision software; radar/lidar sensors; global-positioning system (GPS) tracking; geofencing that defines multiple geofenced zones within the facility; logic circuits within the aerial lift control circuit; and so on, for example in combination with orders issued by a central monitoring/directing station.

[062] Upon arrival at or near arrival at a destination, a user may manually raise the aerial lift as required; or, in some embodiments, the automatic control system may initiate and control the elevation of the lift, subject to constraints imposed by the fall protection monitoring system. The arrangements disclosed herein may be used in such circumstances, for example, by configuring the aerial lift control circuit such that unless the control circuit receives at least a first positive signal from the fall protection monitoring system, the vertical elevation function of the aerial lift will be disabled so that it cannot be raised in response to manual inputs or in response to inputs received from an automatic control system. In some such embodiments, the disabling may occur at least in part by assumptions of decisions made by logic circuitry within the aerial lift control circuitry (e.g., a decision not to raise the aerial lift) rather than by any actual disabling of manual input devices that would be used by a human operator to control the aerial lift. (However, as noted above, in such cases, the manual input devices may also be disabled as an additional protective measure.) In some scenarios, such decisions may be made by logic circuits located at a central routing station with the decisions being transmitted to the aerial lift; however, in many instances, it may be convenient for such decisions to be made on board the aerial lift itself. All such scenarios are encompassed by the provisions set forth in the present invention.

[063] The above discussion of aerial lifts that are controlled at least in part from a remote location, e.g., from a central control station, is one case of a general arrangement in which one or more aerial lifts are monitored telemetrically. That is, in some embodiments, an aerial lift may be a monitored unit of a telemetry system 19. (In many cases, most or all of the aerial lifts in a given facility may be telemetrically monitored, such as a fleet.) In various arrangements, an aerial lift may be telemetrically monitored regardless of whether the aerial lift is partially or completely remotely controlled or is purely manually controlled. In other words, even if an aerial lift is manually controlled, it may still be telemetrically monitored to track parameters and conditions such as, e.g., location, destination, horizontal speed, vertical height, battery status, items currently being transported by the lift, the identity of the person currently operating the lift, and so forth. In some embodiments, the equipment necessary for such monitoring may be installed, e.g., integrated into the aerial lift as manufactured. In some embodiments, some or all of this equipment may be added (e.g., as an optional add-on, depending on user preference). In some embodiments, such a system may perform only monitoring of the aerial lift, e.g., such that the only flow of status information is from the aerial lift to a central monitoring station. In other embodiments, information may flow both ways, e.g., such that the aerial lift operator may receive information such as, e.g., the current destination and/or item to be picked up at the destination. In some embodiments, such information may be displayed on a screen to the operator (whether the screen is, e.g., built into the aerial lift console, or is an additional screen that, e.g., is suspended from a bulkhead overhead from the aerial lift). In some embodiments, the aerial lift may comprise a so-called mobile data terminal 18 or mobile digital computer, which may display information to the operator, and may further comprise an interface (e.g., a touch screen or keyboard) that allows the operator to input information for transmission to a central monitoring station. In some embodiments, at least some of the information flowing through such a telemetry system (including information from one or more aerial lifts and/or information transmitted to one or more aerial lifts) may be transmitted to a portable item (e.g., an application located on a general purpose smartphone, or a dedicated electronic transceiver used only for this purpose), for example, by an authorized person. (This may be done in addition to, or instead of, sending the information to a central monitoring station.)

[064] Thus, in some embodiments, the arrangements disclosed herein may be used, for example, in a highly automated facility such as a distribution center that utilizes a so-called warehouse management system that governs many or all aspects of the tasks for which a centrally directed fleet of fall-protected aerial lifts is used. Such a system may choose and optimize the horizontal travel paths of some or all of the individual aerial lifts, may establish the appropriate workflow strategy (e.g., part selection, batch selection, or zone selection), may subject the aerial lifts to specific workflow and travel optimizations (sometimes called zoning and positioning functions), and so forth. In such environments, the information received from the fall protection monitoring system concerning the state of the fall protection device will be one more parameter that the control circuit of each aerial lift takes into account and/or that a central monitoring and/or control station of the installation takes into account for each aerial lift, to be used in combination with all other parameters that are necessary for partial or complete automatic control of the aerial lift(s).

[065] In some embodiments, a fall protection monitoring system as disclosed herein may send data (e.g., status information about the fall protection monitoring system itself) to an entity or system (e.g., a portal, website, or central monitoring station) that is dedicated purely to tracking the status of one or more fall protection monitoring systems, and that operates independently of any telemetry system that may track other aspects of the aerial lift with which the fall protection monitoring systems are used. However, in some embodiments, at least some of the fall protection monitoring system status information that is sent to such a dedicated system may also be communicated or echoed to another entity, e.g., a telemetry system, a portal, a website, an application residing on a smartphone of an authorized person, and so on.

[066] The telemetry monitoring option provides another means for a fall protection monitoring system disclosed herein to communicate the various signals disclosed herein to an aerial lift so that the desired interlocking of the aerial lift with the fall protection monitoring system can be achieved. That is, rather than such signals being transmitted from the monitoring system to the aerial lift directly, e.g., by a wired connection or by a short-range wireless mechanism (both as discussed in detail later in this document), in some embodiments, the fall protection monitoring system participates in a telemetry monitoring system 19. For example, a base unit of the monitoring system may comprise a communication module that is configured to interface (e.g., wirelessly) with a telemetry network 19. Such an arrangement may enable the fall protection monitoring system to send signals (e.g., a first positive signal) on the telemetry network 19, which may then forward the signals to the appropriate aerial lift. (In various embodiments, such signals may enter the telemetry network and from there to the aerial lift, with or without necessarily passing through a central monitoring station.)

Notifications

[067] In some embodiments, a fall protection monitoring system as disclosed herein may serve merely to send at least a first positive signal or not send any such first positive signal (and possibly in some embodiments send a negative signal) to the control circuit in the manner discussed above. This will allow the aerial lift control circuit to take appropriate action (e.g., to disable the controls so that the aerial lift cannot be raised). In some embodiments, a fall protection monitoring system may additionally serve to transmit various notifications. In some embodiments, such a notification will be a “not ready” warning in the event that the connector is detected as it does not appear to be connected to the user’s harness. In some embodiments, the monitoring system may additionally be configured to transmit a “ready” confirmation if the connector is detected as it appears to be connected to the user’s harness.

[068]By notification is meant a signal that is transmitted to a user of the aerial lift, to one or more persons in the local vicinity, to one or more designated persons, e.g., at a monitoring station, and/or to an automated monitoring or telemetry system, for informational purposes. By definition, any notification is distinguished from the first positive signals described herein that are sent to the control circuit of the aerial lift for the purpose of interlocking the aerial lift with the fall protection system as disclosed herein. Such notification may be, for example, an audible notification and/or a visual notification and/or a haptic notification. Such notifications may be transmitted locally (e.g., by providing the fall protection monitoring system with lights or buzzers) and/or may be transmitted, e.g., to a smartphone or a remote monitoring station.

[069] In some embodiments, a fall protection monitoring system as disclosed herein may be flexibly configured such that although the monitoring system as manufactured is capable of sending at least a first positive signal in the manner described herein, the monitoring system may be modified such that no such signals are sent. Thus, in some embodiments, a fall protection monitoring system may be configured (e.g., as desired by an end-use facility or fleet) to send only notifications and not perform any interlocking of the aerial lift. Providing flexibility to a monitoring system in this regard may provide that the monitoring system may be configured for a customer who desires the system to have interlocking functionality (with or without notifications); or it may be configured for a different customer who desires only notification functionality. In some cases, fall protection monitoring systems supplied to different customers may differ, for example, only in specific firmware or software configurations, so that interlock functionality is disabled (or in some cases, a notification-only system may omit certain components). In any case, such an arrangement is advantageous over manufacturing completely different fall protection monitoring systems, one to provide only interlock (and optionally notifications) and one to provide only notifications.

[070] In some embodiments, the aerial lift may be configured to transmit notifications regarding the readiness state (e.g., hook connection) of the fall protection apparatus, based on information transmitted from the fall protection monitoring system to the control circuit of the order picker. (The aerial lift may also be capable of transmitting notifications regarding the state of various safety apparatus on the aerial lift itself, e.g., an OPC switch, a safety door, etc.) Any such notifications may include warning notifications and may additionally include prompt notifications, informational messages, and the like. Such notifications as transmitted by the aerial lift as a result of information received from the fall protection monitoring system may take the form of, e.g., audible, visual, and/or haptic notifications and may be transmitted locally (e.g., via lights or buzzers on the aerial lift itself) and/or may be transmitted, e.g., to a smartphone or a monitoring station. Thus, by way of specific example, a console 7 of an order picker may comprise at least one notification unit that displays a notification of the state of the fall protection apparatus based on signals sent to the control circuit of the order picker by the fall protection monitoring system. Such a notification unit may take any suitable form, e.g., a green light that illuminates when the monitoring system indicates that the fall protection apparatus is in a “ready” condition; a red light that illuminates when the monitoring system indicates that the fall protection apparatus is not in a ready condition; a set of red and green lights; a display screen that indicates a ready or not ready indication, and so on. Any negative notification (whether displayed by the fall protection monitoring system itself or displayed by the order picker based on information received from the fall protection monitoring system) that contains actual verbiage may take any suitable form, e.g., “not ready,” “unhooked,” “check connection,” and so on. Similarly, any positive notification may use any suitable verbiage, e.g., “ready,” “connected,” etc. Fall protection monitoring systems that are configured to provide notifications are described and discussed in detail in U.S. Patent Application No. 17/435,661, entitled “Fall-Protection System with Monitoring System,” which is incorporated herein by reference in its entirety. In some embodiments, for example, if an aerial lift is telemetrically monitored and is equipped with a display screen or mobile data terminal 18, as previously mentioned herein, any notification may be presented via such display screen or portable data terminal of a telemetry network.

[071] As discussed in detail later in this document, in some embodiments, the fall protection monitoring system may send information to the order picker regarding the state of the fall protection monitoring system. In such cases, the order picker may be configured to display some of this information (e.g., “needs battery change”) on a notification unit of the order picker. In specific embodiments, the order picker may be configured to receive information from the fall protection system such that in the event that the vertical motion function of the order picker is disabled, the order picker may transmit a notification of the reason (e.g., that the disablement is due to a need to change the sensor module battery, not because a proper connection of the locked hook to the operator's safety harness was not detected). Any such information may, for example, be displayed on a display screen of the order picker and/or may be transmitted to a central monitoring station.

Base unit and sensor module

[072] In some embodiments, a fall protection monitoring system of a fall protection safety apparatus (e.g., an SRL) may comprise a base unit 60 and at least one sensor module 34, the sensor module configured to detect whether the connector appears to be connected to the safety harness and transmit connector status information to the base unit. Such a sensor module may thus comprise at least one sensor for detecting the condition of the connector, and a communication module that transmits such information (either wirelessly, or over a wire or fiber optic cable) to the base unit. A base unit may comprise a receiving module that may receive connector status information from one or more sensor modules, and a communication module that, based on the information received from the sensor module(s), may send the aforementioned first positive signal to be received by the control circuit of the aerial lift. In some embodiments, a base unit may also comprise a notification module for issuing or otherwise transmitting a notification as mentioned above. A base unit may comprise any processing circuitry necessary to operate the above-mentioned modules and may comprise any other components as may be necessary for the operation of the base unit and modules thereof.

[073] In some embodiments, a base unit may receive raw (or partially processed) data from one or more sensors from the sensor module and may perform any or all of the actual processing that is necessary to determine the condition of the connector. In other embodiments, the raw data may be at least partially processed by circuitry residing within the sensor module itself. In at least some such cases, the base unit may need to receive only yes/no information from the sensor module indicating whether the connector appears to be connected or not; then, depending on the information, the base unit may or may not send at least a first positive signal to the control circuitry of the aerial lift. It will be recognized, therefore, that the aforementioned arrangement, in which a sensor module is configured to detect whether a connector appears to be connected to a safety harness and transmit connector state information to a base unit, may span the entire range from the sensor module processing all sensor data and transmitting a final determination (connected/disconnected) of connector state to the base unit, to a case where the sensor module simply transmits raw sensor data to the base unit which processes that data to arrive at the final determination of connector state. All of these arrangements are within the general premise of a sensor module detecting whether a connector appears to be connected to a safety harness and transmitting connector state information to the base unit. Furthermore, in some embodiments, the components and functions of a base unit and a sensor module may be fully integrated with each other, as discussed in detail later in this document.

[074] In some embodiments, a sensor module 34 of a fall protection monitoring system may be installed on a connector (e.g., a locked hook) 30 at a distal end of a lifeline 52 of a fall protection safety apparatus. This terminology encompasses arrangements (illustrated generically in Figures 3 and 4) in which the sensor module is located on the connector or is located near the connector (e.g., mounted on the safety line 52 or in a protective housing located thereon), so long as the sensor module is close enough to the connector to allow the condition of the connector to be successfully monitored, for example, to assess whether the connector appears to have been attached to a D-ring. In some embodiments, a sensor module 34 may be installed within an enclosure (e.g., a molded plastic housing) 36 that is fitted over at least a portion of the main body 31 of the connector 30, as indicated in Figure 4. In some embodiments, a sensor module (and also a base unit, if the sensor module and base unit are integrated together as described below) may be at least partially embedded in the material of the connector 30 itself, such that the connector 30 may serve at least partially as a protective housing for the sensor module and/or the base unit.

[075] In some embodiments, a sensor module may be installed on a harness 40 to which the connector 30 is to be attached. For example, a sensor module may be installed on a D-ring (e.g., a dorsal D-ring 41) that is non-removably attached to the harness 40. This terminology encompasses arrangements in which the sensor module is located on the D-ring or is located proximate to the D-ring (e.g., on a strap or a dorsal plate of harness 40), so long as the sensor module is close enough to the D-ring to allow the sensor of the sensor module to evaluate whether a connector appears to have been attached to the D-ring. Arrangements disclosed herein encompass, for example, configurations in which a connector is monitored for an indication as to whether the connector appears to have been attached to a D-ring, as well as arrangements in which a D-ring is monitored for an indication as to whether a connector appears to have been attached to the D-ring.

[076] Other arrangements are possible. In some embodiments, a sensor module may be located in a docking station that is configured to accept the connector 30 when the connector 30 is not connected to the user's harness (such docking stations are discussed in more detail later in this document). In embodiments in which the fall protection apparatus is a self-retracting lifeline (SRL) 50, the SRL may comprise a sensor module that is configured to monitor the position of the connector 30 relative to the enclosure 51 of the SRL. Such a sensor module may comprise, for example, a sensor that is in the enclosure and that is configured to verify that the connector 30 is in close proximity thereto. Or such a sensor module may comprise a sensor that is configured to determine the distance at which the lifeline 52 has been deployed from the enclosure 51 (such a sensor may be, for example, a rotary encoder that tracks the rotation of the spool 53 to which the proximal end of the lifeline 52 is attached). Such a sensor module may thus be configured to provide an indication of, for example, whether connector 30 is firmly pressed against the SRL enclosure or is adjacent to (meaning within 0.2 meters of) the enclosure; or whether connector 30 has been placed at a considerable distance (e.g., more than 0.2 meters) from the enclosure. This information may be used, if desired, as an indication of the condition of the connector. For example, if the connector is recorded to be pressed tightly against the SRL enclosure, this may be inferred to be an indication that the connector does not appear to be attached to an operator's harness.

[077] The above discussions make it clear that a sensor module may be installed, for example, on a connector (e.g., a locked hook), on a D-ring to which the connector is to be attached, on a docking station to which the connector may be attached when not in use, or on an SRL enclosure from which a safety line supporting the connector may be extended. Any such arrangement, and any desired combination of such arrangements, is encompassed by the disclosures of the present invention (noting that, for example, in a configuration in which sensor modules are installed on harness D-rings, a base unit (described below) may be configured such that the base unit is capable of receiving signals from any of multiple possible sensor modules on multiple harnesses).

[078] A base unit 60 of a fall protection monitoring system, which receives information from a sensor module(s) indicative of the condition of the connector, may be positioned in any suitable location. In some embodiments, a base unit 60 may be installed in the aerial lift. For example, a base unit 60 may be installed on, or within, a console 7 of the aerial lift, as indicated in Figure 2. In other embodiments, a base unit may be installed, for example, on an overhead bulkhead 9 of the aerial lift, as indicated in Figure 1. In some embodiments, a base unit of a fall protection monitoring system may be at least partially integrated into the circuitry of the aerial lift itself, and thus may not necessarily be in an enclosure that is physically separate from other items of the aerial lift circuitry. A base unit located in an aerial lift, for example, which is not co-located with a sensor module, may communicate with the sensor module in any suitable manner, for example, via short-range wireless methods such as Bluetooth, Bluetooth LE, LoRa, Zigbee or Wi-Fi; and/or via a wired connection, and/or via a long-range wireless network such as a cellular network.

[079] A base unit and a sensor module are not necessarily limited to any of the above arrangements; in particular, a base unit is not limited to being installed on an aerial lift itself. For example, in some embodiments, a base unit may be installed on or over a connector of a lifeline. In some such embodiments, a base unit may be co-located with a sensor module that is on or over a connector (e.g., a locked hook) of a lifeline of a fall protection apparatus. In some such co-location embodiments, a base unit and a sensor module may be integrated with each other, for example, so as to reside at least partially within a single physical unit or enclosure. For example, electronic components that form a base unit, and those that form a sensor module, may all be arranged on a single printed circuit board or flex circuit. (In such cases, it may be convenient to operate the base unit and the sensor module from the same power source.) In such a co-located, e.g., integrated, design, it is not necessary for the components that form a base unit and those that form a sensor module to be grouped separately. Instead, any such components may be intermixed.

[080] Based on the above discussions, it is clear that there is no need for a base unit that has all of its components in a single location. Instead, a base unit may be configured, for example, with one or more components co-located with a sensor module, for example, in a connector (and, for example, powered by a battery located in the connector), and one or more other components that are in a separate location, for example, in a separate enclosure mounted somewhere in the aerial lift. Thus, it has been emphasized that there are no specific restrictions on base units and sensor modules. For example, in some embodiments in which a base unit and a sensor module are integrated with each other, a base unit may be reduced to essentially a communication module in the form of, for example, a short-range wireless radio and circuitry to operate the radio. Similarly, a sensor module may be reduced to essentially one (or more) sensors and circuitry to operate the sensor(s). A common power source (e.g., a battery) may be used to power an integrated sensor module/base unit. Since in such a scenario the “base unit” and the “sensor module” will likely be in close proximity to each other, a hardwired connection may be convenient to allow the sensor module to communicate connector state information to the base unit’s communication module (with the hardwire connection thus serving as both a sensor module’s communication module and a base unit’s receiving module). Any processing circuitry that analyzes sensor information may be considered part of the base unit and/or a part of the sensor module, since in such an embodiment the base unit and the sensor module may be completely integrated with each other.

[081] The term “base unit” is used herein for convenience in describing an entity or collection of entities that perform, alone or in combination, certain functions involved in the interlocking arrangement disclosed herein. As a reminder, such functions will comprise, at a minimum, receiving connector status information from a sensor module and sending a first positive signal directly or indirectly to an aerial lift. The term base unit therefore does not imply any specific physical construction or physical location. In particular, a base unit need not necessarily be a relatively bulky item that is mounted on an aerial lift and is spaced some distance from a sensor module with which it cooperates. Rather, in some cases, a base unit may be quite small and may be integrated together with a sensor module, e.g., in a connector.

[082] Thus, for example, a collection of hook-mounted items that includes at least one sensor that detects a connector state, a wireless transmitter/receiver (e.g., a Bluetooth LE radio) that receives connector state information from the sensor and (based on the connector state information) wirelessly sends a first positive signal to the operating circuitry of an aerial lift, together with any items necessary to power and operate the sensor and transmitter/receiver, will be considered to comprise a sensor module and a base unit that are encompassed within the disclosures of the present invention.

[083] In various other embodiments, a base unit may be installed on the harness, e.g., on a D-ring. In such embodiments, the base unit may be co-located with a sensor module that is installed on the D-ring and may receive signals from it; or the base unit may be installed on the harness but may receive signals from a sensor module that is installed on the connector rather than on the D-ring. In some embodiments, a base unit may be installed in (e.g., on or within) an enclosure of a self-retracting lifeline.

[084] Any of these are possible. In some convenient embodiments, a base unit 60 may be installed near, on, or within a console 7 of the aerial lift, as noted above. This may advantageously position the base unit near the aerial lift control circuit 17 and/or may make it convenient for the base unit to draw power from the aerial lift rather than having to have its own power supply. This may also make it easier for the base unit to transmit any early positive signals to the aerial lift control circuit via a wired rather than wireless connection, although either may be acceptable. (In this context, a “wired” connection broadly encompasses any physical connection using electrically conductive wire, fiber optics, etc.) In some embodiments, a base unit may be mounted generally above the operator of an aerial lift, for example, on an overhead bulkhead 9 of an aerial lift. Such a location may be advantageous, for example, if it is desired to provide a mechanism for detecting the presence of an operator, for example, through the use of one or more proximity sensors as discussed elsewhere in the present invention.

[085]The term sensor module is used generally to describe an item, or collection of items, that includes at least one sensor that performs sensing to acquire connector state information, a communication module (which may take the form of, for example, a wireless transmitter, or a simple wired connection) to send the connector state information collected by the sensor to a base unit, and any necessary hardware, software, and so on (including, in some cases, a power source), to operate the sensor(s), process the information as needed, operate the communication module, and so on. The sensor module may, for example, be partially or completely contained within an enclosure, e.g., a molded plastic enclosure, which enclosure may, for example, be attached to or otherwise disposed over a connector or a D-ring. In some embodiments, the sensor module may be attached, for example, to a lifeline or housing thereof, or to a component (e.g., a strap or backplate) of a harness, so long as the sensor of the sensor module is positioned in a location that allows it to perform its desired function.

[086] The term sensor module is used for convenience in describing certain functions involved in the interlocking arrangement disclosed herein and does not imply any specific physical construction. For example, embodiments have been discussed above in which a sensor module and a base unit are highly integrated; in particular, an arrangement has been described that comprises one or more sensors, a wireless transmitter/receiver (e.g., a Bluetooth LE radio) that communicates a first positive signal to the operating circuit of an aerial lift, and various items as necessary to operate the sensor(s) and transmitter/receiver. In this case, a sensor module of such an integrated base unit/sensor module may comprise only the sensor(s) and a communication module that sends information collected by the sensor(s) to the wireless transmitter/receiver (in other words, to a “base unit” of the integrated base unit/sensor module). The “communication module” of the sensor module may be just one or more wires, optical fibers, or even conductive tracks on a circuit board or flexible circuit, that connect the sensor(s) to the wireless transmitter/receiver.

[087] Based on the above discussions, it will be recognized that in some embodiments, a short-range wireless radio that is present at a connector of a lifeline of a fall protection monitoring system can serve as a communication module of a sensor module, e.g., in an arrangement in which the wireless radio sends connector status information to a separately located base unit that then sends a first positive signal to the control circuitry of an aerial lift. In other embodiments, a wireless radio that is present at a connector of a lifeline of a fall protection monitoring system can serve as a communication module of a base unit, e.g., in the case of an integrated base unit/sensor module in which the wireless radio receives connector status information from a sensor module (e.g., via a wired connection) and the hook-mounted wireless radio itself sends a first positive signal to the control circuitry of an aerial lift. Any such scenario, and various modifications thereof, are encompassed by the disclosures of the present invention.

[088] In some embodiments, a first sensor of a sensor module may be configured to detect one or more metals. This may be useful since the connectors (hooks/carabiners) of the apparatus and fall protection items (such as D-rings) to which such connectors are connected are typically made of metals such as steel and the like. Thus, a sensor located on a D-ring or docking station may be capable of detecting the presence of a metal connector; conversely, a sensor located on a connector may be capable of detecting the presence of a metal D-ring. In specific embodiments, any such sensor may be configured to particularly detect a metal item or a portion thereof that is positioned within or near an opening defined by the entity on which the sensor is installed. For example, a connector (e.g., a locked hook) may be equipped with a sensor module, such sensor or sensors being configured to detect a portion of a metal item (e.g., a D-ring) that is within, or near, the opening defined by the hook. Any sensor, if installed on, or near, an entity that is made of metal, can be configured to compensate for such metal (i.e., the sensor can be configured to detect the presence of an additional metal item, above and beyond the metal that is already there).

[089] In some embodiments, such a sensor may rely on electromagnetic sensing. In some embodiments, such a sensor may rely on inductive sensing. In some such embodiments, such a sensor may interrogate and monitor changes in a resonant frequency of an electronic circuit of an inductive sensor (which changes may result, for example, from eddy current phenomena that are generated when a metal item is placed in an inductive field). Inductive sensing in general, and the utilization of eddy current phenomena in particular, are discussed in detail in U.S. provisional patent application No. 62/628,720, and the resulting PCT application published as WO 2019/157007, both of which are incorporated herein by reference in their entirety. It will be recognized that many of the principles, arrangements, and methods disclosed herein may be useful for purposes of the present application.

[090] Although the above discussions have been primarily concerned with the detection of metal items, e.g., by inductive sensing, it will be recognized that any sensor, having any sensing mechanism, may be used to detect whether an item is present in an opening of a connector, such as a locked hook (more generally, such a sensor, or sensors, may detect, in any suitable manner, whether the connector is connected to an item, e.g., to a D-ring of a safety harness). In various embodiments, such a sensor may be any type of electromechanical sensor, e.g., a load cell that can detect whether the hook has been placed under load.

[091] In some embodiments, such a sensor may be an RFID or NFC reader that is configured to detect an RFID or NFC tag or beacon that is present on or in the item (e.g., a D-ring, a docking station, etc.) to which the hook is to be connected. For example, a sensor of a sensor module may comprise an RFID reader that is mounted on a connector (e.g., a locked hook) at the end of a lifeline of an SRL, the RFID reader being configured to read an RFID tag that is situated on or in a D-ring of a user's fall protection safety harness. The effective range at which the RFID reader can read the RFID tag may be adjusted such that a positive recognition by the RFID reader of the RFID tag may be considered as an indication that the connector is connected to the D-ring. Any suitable variation of these arrangements may be used; for example, in the case of a personal SRL as discussed later herein, an RFID tag may be located on an anchorage rather than on a D-ring of a safety harness. Or, in some cases, an RFID reader may be located on a harness D-ring or on an anchorage and may be configured to read an RFID tag that is located on a connector (e.g., a locked hook) of an SRL. In embodiments in which an aerial lift is a multi-occupant lift, as discussed elsewhere herein, multiple anchorage points may be present, each with an RFID tag (or an RFID reader). In various embodiments, all of these RFID tags may be generic; or they may be uniquely identifiable when read by an RFID reader. In some embodiments, a detection scheme based on RFID tags and readers may be used in combination with a door sensor of the general type discussed below.

[092] In other embodiments, other detection mechanisms, for example, relying on one or more optical sensors, one or more mechanical switches, one or more ultrasonic sensors (or proximity sensors of any suitable type and operating mechanism), and so on, may be used.

[093] In some embodiments, at least one other sensor may be used, operating by any sensing mechanism and provided at any specific location and/or applied to any specific step or operation in the use of the connector 30 or the fall protection apparatus in general. Such a second sensor may operate by some mechanism other than detecting whether an item is present in the opening defined by the hook. Although in some embodiments such a sensor may be used in place of the above arrangements, in many advantageous embodiments such a sensor may be used in combination with the arrangements described above. For example, in some embodiments, a hook may be provided with a port sensor that can monitor the state of a port of the connector. Such a sensor may be used, for example, in combination with any of the other sensors described herein. For example, in some embodiments, one or more first sensors may be used that are inductive sensors configured to determine whether a metal item (e.g., a metal D-ring) is present in the opening of the connector; and one or more second port sensors may be used to monitor the state of a port of the connector.

[094] Any such data or indication provided by a door sensor will fall under the general category of reporting whether the door is “secured” or “not secured”. In some embodiments, it may not be the case that, for example, a door on a hook must actually be in an open position to be reported as “not secured”. Rather, the door may merely be, for example, unlocked or not fully secured. For example, a connector may be a double-acting connector of the general type noted above, for example, a “twist lock” hook in which a locking mechanism (e.g., collar) of the hook door must be rotated slightly to unlock the door so that it can then be opened. A door sensor may be configured to report that the door is not secured, for example, if it is detected that the locking collar does not appear to have been rotated to its fully locked position, even though the door itself has not actually been opened.

[095] In some embodiments, a second sensor, such as a door sensor, may operate by a different mechanism than the first sensor or sensors. For example, in some embodiments, a door sensor may be a so-called Hall effect sensor. In some embodiments, such a sensor may be configured to detect the presence or absence (within a predetermined distance) of a magnetic beacon that is purposefully installed on the door. For example, such a magnetic beacon (e.g., a piece of any suitably magnetic material) may be installed in a cavity provided in a twist portion (e.g., a locking collar) of the door. The door sensor may detect the magnetic beacon, and report its presence, when the beacon is in close proximity to the sensor (e.g., when the door is closed and the locking collar is in its locked position). The sensor may report the absence of the magnetic flag upon the locking collar being rotated in the direction opposite its locked position (thus moving the flag away from the sensor) to allow the door to be opened. In some embodiments, either door sensor may be alternatively configured (e.g., the sensor and the magnetic flag may be positioned) to detect the flag when the door is not latched and detect the absence of the flag when the door is latched.

[096] As noted previously, in many embodiments, the output of a fall protection monitoring system as disclosed herein will include at least a first positive signal, based on indications received from at least one sensor or sensors. In some embodiments in which both first and second sensors are used, an indication from the first sensor alone, or an indication from the second sensor alone, may not be sufficient to allow a first positive signal to be generated. That is, in some embodiments, adequate indications must be received from both a first sensor and a second sensor. Thus, for example, a monitoring system for a locked hook may be configured such that data must be received from a first sensor indicating that a metal item (e.g., a D-ring) is or has been detected in the opening of the hook; and, data must be received from a second sensor indicating that the door of the hook is locked, in order for a first positive signal indicating that the connector of the fall protection apparatus appears to be connected to a harness of a user of the aerial lift, to be output. The use of information from the first and second sensors in combination in this general manner is described in more detail, for example, in U.S. provisional patent application No. 62/978024 and the resulting PCT application published as WO 2020/194121, both of which are incorporated herein by reference in their entirety.

Power management

[097] In some embodiments, a sensor module 34 may be powered by an internal power source, e.g., a battery 37. The term “internal” means that the power source/battery is situated within the same general enclosure (e.g., enclosure 36 as shown in Figure 4) within which the sensor module is situated; the battery need not be within the sensor module itself, although in some cases it may be. If the sensor module is situated, e.g., within an enclosure 36 provided on a connector 30, then (depending on the size of the enclosure and connector) the space available for a battery may be limited. In some cases, the battery may need to take the form of one or more small, low-capacity batteries (e.g., AAA, “coin,” or “button” batteries) in order to fit within the available space. (Other power sources, e.g., one or more rechargeable batteries or rechargeable supercapacitors, and so on, may be envisioned, but would still need to fit within the available space.) Thus, in some embodiments, it may be advantageous to configure, and operate, the first and second sensors of the sensor module in a manner that will maximize battery life without compromising sensor module performance.

[098] For example, in embodiments in which a first sensor is an inductive sensor that detects whether a metal item such as a D-ring is present within an opening of a locked hook, and in which a second sensor is a door sensor that is a Hall effect sensor that detects whether the connector door is closed and secured, the first inductive sensor, when active, may exhibit a power consumption that is greater than the power consumption of the second Hall effect sensor, by a factor of ten, one hundred, or even one thousand or more. Accordingly, in some embodiments, the circuitry operating the first and second sensors may be configured such that the first inductive sensor is not activated until the second Hall effect door sensor has detected a change in the state of the door, e.g., has detected that the door has become unsafe. The first sensor may then remain in active operation for a selected period of time as long as the door remains in a specific condition (e.g., unsafe), and possibly for an additional selected period of time after the door has returned to another condition (e.g., becoming stuck). Thereafter, the first sensor may be returned to an inactive state in which it consumes little or no power. When a change in the door state is again detected, the first sensor may be activated again. Otherwise, the first (inductive) sensor may remain off, and thus the sensor module as a whole may remain in a low-power consumption state indefinitely.

[099] The first and second sensors may thus be configured for efficient power management, under the general principle that a higher power consuming sensor need only be triggered to become active upon a suitable signal that is received from a higher power efficient sensor. In the specific example provided above, a second low power consuming Hall effect sensor may be operated at least quasi-continuously (e.g., to interrogate the state of a door up to several times per second or even continuously), while a first high power consuming inductive sensor may remain inactive until triggered to become active in response to a change in the state of the door indicated by the second door sensor. Such arrangements allow a base unit of a fall protection monitoring system to continue to send at least a first positive signal to the control circuit of an aerial lift (thus allowing the vertical movement function of the aerial lift to remain enabled) so long as the base unit continues to receive information from the sensor module indicating that, according to the second door sensor, the locked hook door continues to remain closed and latched. The first inductive sensor may remain inactive during this time, so that the sensor module as a whole remains in a low-power usage state.

[0100] The above arrangements are merely an example of how a sensor module comprising at least a first high-power sensor, and at least a second low-power sensor, may be configured for efficient use of battery power. Other scenarios are possible. For example, in the above scenario, the sensor module continues to send information to the base unit that the hook door remains closed and secured. This information may be sent over a short-range wireless radio (e.g., over a Bluetooth or Bluetooth low energy radio that the sensor module is equipped with). In some conditions, the short-range wireless radio itself may be turned off, thereby providing additional power savings. Thus, in a specific example, if an order picker is turned off (e.g., for an operator lunch break) such that power to the base unit of the fall protection monitoring system is turned off, the short-range wireless radio of the sensor module will not receive a response to its continued signals to the base unit. The sensor module can be configured so that if the sensor module does not receive a response from the base unit for a predetermined amount of time (e.g., 1, 2, 5, 10, 30, or 60 minutes), the sensor module's short-range wireless radio (and/or any other components that are not required) will be turned off. At this point, the sensor module will be in a very low power usage state.

[0101] In such a very low power usage state, the sensor module may, for example, be using power only to run a very low power consumption sensor, such as a Hall effect sensor mentioned above, to continue any processor functions that are necessary to run the sensor, to continue any processor functions necessary to allow the sensor module to return to a fully active operating condition upon detection of a suitable sensor signal, and so on. Such a state may minimize battery drain to a very low value, for example, during a period when the order picker is not operating. In some embodiments, other functions or low power usage states of the sensor module's operating circuitry may be maintained. For example, an internal clock may continue to operate and may periodically wake up a short-range wireless radio to listen for any signal from the base unit.

[0102] In a variation of this that may be particularly useful, for example in the case of a base unit and sensing module that are integrated with each other in a connector, the integrated sensing module/base unit may be configured to enter a very low power usage state if no signal is received from the airlift (e.g., by a short-range wireless radio of the integrated sensing module/base unit) for a predetermined period of time. While in this very low power usage state, the integrated unit/module may use only an amount of power necessary to maintain the short-range wireless radio in order to be able to receive a signal from the airlift. When such a signal is received, the integrated unit/module may be restored to full operation.

[0103] The scenario described above, in which a very low power consumption sensor, such as a Hall effect sensor, is monitored such that the sensor module can return to a normal operating condition when triggered to do so by the low power consumption sensor, may have an additional advantageous effect. Specifically, this may provide that the sensor module does not need to have a physical on/off switch. Instead, to return to the example provided above, when an operator returns from a lunch break, the operator may simply manipulate the hook door 32 (e.g., may twist a collar 33 of the door, in which collar a magnetic beacon is embedded) to reactivate the sensor module 34 from a very low power usage state. Thus, in this case, a hook door may serve as a de facto “on/off” switch, with a separately provided on/off switch not being required. It is highly advantageous for the hook port to serve in this manner, as the manipulation of the hook port that will be required to reattach the hook to the D-ring of the operator's harness will serve to reactivate the sensor module (and thus "turn" the monitoring system back on) without any further action being required to reactivate the sensor module.

[0104] Strictly speaking, manipulating the door in this manner will not power the sensor module from a completely de-energized state, but rather will activate it from a very low power consumption state as described above (in which state the door sensor and selected functions of the sensor module's operating circuitry are still active). However, it has been found that the power drain in this state is so small (e.g., in the range of a few microwatts) that in most cases there is no need to provide a means to completely “power down” the sensor module. Such arrangements may advantageously allow the sensor module to return to a fully active state extremely quickly and may minimize the chances of inadvertently turning off the sensor module due to incidental contact with an on-off switch during work activities.

[0105] It will be recognized that in embodiments in which a base unit and a sensor module are co-located, e.g., in a connector, and in particular in arrangements in which these entities are integrated with one another in the general manner described hereinbefore, the above discussions regarding the need to conserve power, and minimize (or completely cut off) power to various components and functions, will apply in a similar manner to the components of a base unit that is integrated with a sensor module. On the other hand, a base unit that is, e.g., connected to the circuitry of an aerial lift may be powered by the power source of the aerial lift itself and may have no need for such reduced power consumption arrangements.

[0106] Other arrangements of this general type may be provided in which a low power consumption detection method may be used to wake up a sensor module (and/or a base unit, e.g., if the base unit is integrated with the sensor module) from a low power consumption state; e.g., from deep sleep. For example, a sensor module that is installed, e.g., in a connector of a monitored fall protection apparatus may comprise one or more accelerometers. Such an accelerometer may be configured to detect, e.g., movement indicative of the connector being manipulated by a person, movement indicative of the operation of an aerial lift to which the connector is mounted, and so on. Thus, in some embodiments, a sensor module may comprise an accelerometer for purposes of determining that operation of an aerial lift has begun and appropriately placing one or more components (e.g., a sensor module) of the fall protection monitoring system into full operational readiness. When in a low-power state, the system may drain power only to the extent necessary to operate the accelerometer; motion detection by the accelerometer may then trigger a component (e.g., a sensor module) to become fully operational or to become operational to any designated extent. The same may apply to a base unit if the base unit is situated, e.g., integrated, with the sensor module.

[0107] In some embodiments, a fall protection monitoring system may be equipped with the ability to detect the presence of an operator, e.g., a person standing on an operator support platform of an order picker type of aerial lift. (In a slight modification, an aerial lift itself, as manufactured, could be equipped with such functionality, e.g., with the aerial lift being configured to provide such information to the fall protection monitoring system.) Such arrangements may make use of an operator detection module, e.g., a proximity detection module comprising one or more proximity sensors, operating by any suitable mechanism. In some specific embodiments, this may rely on one or more range proximity sensors, e.g., time-of-flight laser proximity sensors.

[0108] In some embodiments, a fall protection monitoring system may rely on information from an operator detection module to properly place one or more components (e.g., a sensor module) of the fall protection monitoring system into full operational readiness. When in a low power consumption state, the system may, for example, draw power only to an extent necessary to operate the operator detection module; detection of the presence of an operator may then trigger one or more other components of the monitoring system (e.g., a sensor module) to become fully operational or to become operational to any designated extent.

[0109] Any operator sensing module may be configured to provide its obtained information to the fall protection monitoring system in any suitable manner. For example, in some embodiments, one or more proximity sensors may be physically connected to a base unit (e.g., with the base unit and the one or more proximity sensors being mounted on an overhead bulkhead of an aerial lift). In this arrangement, the base unit may supply power to the proximity sensors; and the proximity sensors may send their information to the base unit via a wired connection thereto. If operator sensing is used as the basis for activating a sensor module from a low-power state, the operator sensing module may communicate the information to the sensor module in any suitable manner, e.g., via short-range wireless mode. For example, an integrated base unit and sensor module (e.g., in a locked hook) may include a short-range wireless radio that is maintained in operation when in the low-power state so that information can be received from the operator sensing module. Thus, in various embodiments, an operator sensing module may be used to activate a sensor module and/or base unit from a lower-power state; or, in general, to provide any chosen functionality or functionalities of a base unit and/or sensor module in a more active state. Additional details of operator sensing are described and discussed in U.S. Patent Application No. 17/435,661, entitled “Fall-Protection System with Monitoring System,” which is incorporated herein by reference in its entirety.

[0110] In some embodiments, the initialization and/or operation of at least some components of a fall protection monitoring system may be configured to act in cooperation with an operator authentication device of the aerial lift. For example, a base unit may be powered by an auxiliary power circuit of an aerial lift, with the aerial lift being configured such that the auxiliary power circuit is not activated until an operator has been authenticated, e.g., by means of an operator authentication device of the general type described above. In this case, the base unit may not begin to operate until the operator has, e.g., a badge (in other words, the fall protection monitoring system may itself be interlocked with an operator authentication device).

[0111] In various embodiments, any combination of any of the arrangements discussed above may be used, for example, such that a base unit, a sensor module, and/or an integrated base unit/sensor module may be restored to full operation (and power consumption) in more than one possible manner, as triggered by any of the two or more arrangements disclosed. Thus, for example, an integrated base unit/sensor module may be configured such that, when in a very low power consumption state, a short-range wireless radio is maintained in operation and a low-power sensor (e.g., a Hall effect door sensor) is maintained in operation, such that a wake-up may be triggered by the wireless radio receiving a signal from the aerial lift, or by the low-power sensor detecting, for example, a change in registration state. Similar arrangements could be used with the combination of a short-range wireless radio and an accelerometer.

[0112] The arrangements discussed above may be used most advantageously in the case of items that rely on their own power source; in particular, items (such as, for example, a hook-mounted sensor module or hook-mounted integrated sensor module/base unit) that are in a location where there is limited space for a battery. On the other hand, an item such as a base unit that is hard-wired into the circuitry of an aerial lift may be able to draw power directly from the aerial lift, so that there may be little or no need to set up an arrangement to reduce the power consumption of such an item during periods when the fall protection monitoring system and the aerial lift are not in actual use. Of course, any item that receives its power from an aerial lift may be turned off when the aerial lift itself is turned off. Indeed, an item that does not receive power from an aerial lift may nevertheless turn itself off (or at least return to low-power mode or deep sleep) if it receives a signal indicating that the aerial lift with which it is being used is being turned off.

Early supplementary positive signs and self-check

[0113] With the fall protection monitoring systems and exemplary components and features thereof that have been described, the purpose of the first positive signal(s) transmitted from the fall protection monitoring system to the order picker control circuit to enable at least the vertical movement function of the order picker can be discussed in more detail. Discussions thus far have focused on the fall protection monitoring system sending a single positive signal that is indicative of whether the lifeline connector appears to be connected to the user's safety harness. In some embodiments, this may be sufficient for the order picker control circuit to enable at least the vertical movement function of the order picker. However, in various embodiments, any number of first positive signals may be sent by the fall protection monitoring system. Any such first positive signals greater than one will be referred to as “supplemental” first positive signals, to distinguish them from the previously described “additional” positive signals. Thus, as a reminder, any positive signal sent to the order picker by the fall protection monitoring system is a “first” positive signal, which designation includes any “supplemental” first positive signals. Any positive signal that is sent to the order picker by a safety device on the order picker itself (e.g., an OPC switch, a safety door, etc.) rather than by the fall protection monitoring system is called an “additional” positive signal.

[0114] In an arrangement involving multiple first positive signals, the order picker control circuitry may be configured such that it must correctly receive all of the first positive signals necessary to enable at least the vertical movement function of the order picker. In some such embodiments, one or more supplemental first positive signals may be present to add redundancy. Thus, for example, a first positive signal may be indicative of whether the safety line connector appears to be connected to the user's safety harness, and a supplemental first positive signal may likewise be indicative of whether the safety line connector appears to be connected to the user's safety harness. In such arrangements, the order picker may need to receive both signals to enable the desired function(s) of the order picker.

[0115] In some embodiments, one or more supplemental first positive signals may be used so that the condition of the fall protection monitoring system itself may be taken into account when determining whether to enable the desired function(s) of the order picker. For example, the fall protection monitoring system may be configured to perform a self-check of, e.g., the functionality and readiness of any or all of the electronic components, firmware, communication systems, and so forth, of the sensor module and/or base unit of the fall protection monitoring system. In such embodiments, multiple supplemental first positive signals may or may not be output depending on the readiness of the base unit and sensor module as assessed in the self-check.

[0116] Such arrangements may provide that at least the vertical motion function of the order picker may not be enabled if a readiness self-check reveals that, for example, the fall protection monitoring system is in the midst of a firmware update, a Bluetooth radio of the sensor module and a Bluetooth radio of the base unit are in the midst of wirelessly pairing with each other, or if there is a temporary communications outage between the base unit and the sensor module. (It will be understood that these are exemplary conditions and various other conditions may have a similar effect.) That is, if any of these (or any other potentially problematic conditions) are discovered in the readiness self-check of the fall protection monitoring system, the first positive signal or corresponding supplemental signals will not be transmitted to the control circuitry of the order picker.

[0117] In another example, one or more supplemental positive first signals may be used so that the condition of a sensor module battery may be taken into account when determining whether to enable desired order picker function(s). Thus, for example, the fall protection monitoring system may be configured to assess the remaining battery life of the sensor module. If this remaining battery life is above a pre-selected threshold, a supplemental positive first signal will be sent to the order picker. If the remaining battery life is at or below the threshold, the supplemental positive first signal will not be sent. In some embodiments, the assessment of battery life and the action taken based thereon may be multi-stage. Thus, for example, if the assessed battery life is slightly low, but is not below the threshold described above, the fall protection monitoring system may merely issue a notification that the battery should be replaced in the near future. If the rated battery life is at or below the limit, the first supplemental positive signal will not be issued. Additionally, a notification may be issued that the battery needs to be changed before the order picker can be used.

[0118] In some embodiments, a self-check of the readiness of the fall protection monitoring system may extend to a check of at least some components, or aspects, of the fall protection apparatus itself. Thus, for example, one or more supplemental first positive signals may be dedicated to reporting the readiness of an energy absorber (if one is present in that particular fall protection apparatus) and may be taken into account when determining whether to enable the desired function(s) of the order picker. As noted hereinbefore, many energy absorbers comprise belt segments that are, for example, accordion-folded together and secured to one another, for example by stitching, so that they can be separated from one another to absorb energy in the event of a fall. In some embodiments, one or more sensors may be installed on such an energy absorber and may report whether the energy absorber appears to be in a ready condition or whether, for example, some segments appear to have become somewhat separated from each other or are otherwise comprised. If this latter condition (or any condition that calls into question the readiness of the energy absorber) is detected as possibly present, the fall protection system may refrain from issuing a corresponding complementary first positive signal. (In some embodiments, the system may also issue a notification that the fall protection apparatus, in particular the energy absorber, may require maintenance.) It is provided, however, that any interlocking and/or notification arrangement based on monitoring of the energy absorber shall not negate the need for inspection of the energy absorber, for example, in accordance with all applicable laws, rules, codes, standards, and so forth. Energy absorbers of other designs (e.g. not based on folded/stitched belt segments) can similarly be monitored by means of one or more sensors that are suitable for that type of energy absorber.

[0119] In various embodiments, any of the supplemental first positive signals disclosed above, alone or in combination with any other positive signals, may be used. Thus, in various embodiments, an interlocking approach as described herein may rely on multiple first positive signals (e.g., two to five, ten, or more) that must be sent by the fall protection monitoring system, and received by the order picker control circuit, to enable at least the vertical movement function of the order picker. Exemplary arrangements by which such multiple first positive signals may be transmitted from a fall protection monitoring system to an order picker will be set forth later in this document.

[0120] The above discussions thus reveal that in embodiments in which a fall protection monitoring system is configured to perform self-checks of multiple (e.g., first, second, and third) components of the fall protection monitoring system, a base unit may be configured to output multiple (e.g., up to three) supplemental positive signals, all of which will need to be received by the operating circuitry of the aerial lift to enable at least one vertical movement function. Thus, for example, a first self-checked component of the fall protection monitoring system may be a sensor module, a second self-checked component of the fall protection monitoring system may be a base unit, and a third self-checked component of the fall protection monitoring system may be an internal battery that powers at least one sensor module. However, in some embodiments, the results of any of these self-checks may be combined into a smaller number of signals. For example, a single supplemental positive first signal may be sent if all components (e.g., all three components, in the above example) of the monitoring system each pass a self-check, with the single supplemental positive first signal not being sent if any of the components fails the self-check. Indeed, in some embodiments, the findings of one or more self-checks may be combined into the previously discussed first positive signal, such that the presence or absence of a first positive signal is based not only on whether or not the connector is connected, but also on the operational readiness of one or more components or aspects of the monitoring system itself, as assessed by one or more self-checks of the monitoring system. However, in some embodiments, it may be preferred that the connection status information, and various self-check information, be the object of different first positive signals, for example, so that if an aerial lift is prevented from ascending, it can be more quickly determined whether this is the result of an apparent failure to connect properly or is the result of a problem with some specific component of the fall protection monitoring system itself. It will be recognized that many variations of such arrangements are possible. For example, in the case of a sensor module and a base unit integrated together, a single self-check may evaluate both in a single operation.

Communication

[0121] A base unit (or units), a sensor module or modules, the control circuitry of the aerial lift, and so on, may communicate in any desired manner. In some embodiments (e.g., where a base unit is mounted on the aerial lift and a sensor module is on a connector of a fall protection apparatus), communication between a base unit and a sensor module may be wireless. This may be accomplished, for example, by a short-range wireless method such as Bluetooth, Bluetooth Low Energy (LE), LoRa, Wi-Fi, or any other suitable method or protocol. Or it may be accomplished over a cellular network.

[0122] In other embodiments (e.g., where a base unit is co-located, e.g., integrated, with a sensor module) a wired connection may be used. In some embodiments, such a wired connection may be a physical wire or fiber optic. In some embodiments, e.g., where a base unit and a sensor module are integrated with each other so as to, e.g., reside on a common printed circuit board or flex circuit located, e.g., within a plastic enclosure or enclosure mounted to a connector of a fall protection safety apparatus, the wired connection may take the form of one or more conductive tracks, e.g., on such a circuit board or flex circuit.

[0123] In various embodiments, communication between a base unit and a sensor module may be two-way or one-way, as desired. For example, in some embodiments, a sensor module may wirelessly transmit to a base unit, but not vice versa. In such embodiments, the sensor module may, for example, take sensor readings, for example, on a predetermined schedule, and transmit the results to the base unit. However, in many embodiments, it may be preferable to have two-way communication, for example, so that the base unit may transmit software or firmware updates to the sensor module, may respond to the sensor module to confirm that the base unit is awake and functioning, and so forth.

[0124] In some embodiments, a base unit may, either on a predetermined schedule or in response to an event, send an instruction to the sensor module to take a sensor reading and return the result to the base unit. The sensor module(s) and base unit(s) may be configured in the usual manner to perform an electronic handshake or the like, for example, to ensure that (particularly in cases where multiple aerial lifts operate in close proximity) the base unit is communicating with the appropriate sensor module, and vice versa. As discussed hereinbefore, in some embodiments, a sensor module may be configured to send an intermittent, quasi-continuous, or continuous signal (e.g., via Bluetooth low energy) to a base unit until such time as the sensor does not receive a response/acknowledgement from the base unit for a predetermined time interval, at which point the sensor module may cease sending the signal until it is reactivated in the general manner described hereinbefore.

[0125] Communications between a base unit and the control circuit of an aerial lift may take any suitable form, e.g., wired or wireless (e.g., using any of the methods shown above); and any such communication may be one-way (base unit to control circuit) or may be two-way. Furthermore, any such communication may be direct (e.g., a base unit may communicate with an aerial lift via a wired connection or via a short-range wireless method such as Bluetooth LE); or may be indirect (e.g., a base unit may communicate with an aerial lift via a telemetry network of which the fall protection monitoring system and the aerial lift are members). In some embodiments, the wireless communication may be accomplished via a cellular network.

[0126] In various embodiments, any communication (whether, for example, between a base unit and a sensor module, between a base unit and an aerial lift, or between an integrated base unit/sensor module and an aerial lift) may be analog or may be digital. For example, at least a first positive signal may be converted to digital form and then transmitted (whether wirelessly, for example, via Bluetooth low energy, or by a wired connection, such as provided by an electrically conductive wire or fiber optic cable) to the control circuitry of the order picker. Any necessary analog-to-digital conversion may be performed at any suitable point along the path of the data stream, by any suitable converter (regardless of whether such converter is considered to be part of a sensor module, or part of a base unit, again noting that in some embodiments, such entities may be integrated with each other).

[0127] As noted above, in some embodiments, a base unit and operating circuit of an aerial lift and/or a base unit of an integrated base unit/sensor module and operating circuit of an aerial lift and/or a base unit and a sensor module may communicate via a short-term wireless method such as Bluetooth low energy. In some cases, it may be necessary for the items to reestablish contact with each other. This may happen, for example, after a battery replacement of a sensor module and/or an integrated base unit/sensor module, after a power down of the aerial lift operating circuit that is responsible for maintaining communication with the base unit (e.g., if the aerial lift as a whole is powered down), or after an SRL in which a base unit and/or sensor module is installed is temporarily removed from the short-range wireless radio range of the aerial lift, among other possibilities.

[0128] To allow for such interruptions or eventualities, the items (e.g., respective Bluetooth LE radios) may be configured to re-establish contact with each other. In some cases (e.g., after a short communication interruption that does not involve a loss of power), this may be performed automatically (e.g., in the event that previous pairing information remains intact). In other cases, it may be necessary to re-pair the items with each other; in some cases, this may be done automatically; in other cases, data entry or some other registration procedure may need to be performed.

[0129] It is thus noted that in some cases, a sensor module may be out of contact with a base unit, and/or an integrated sensor module/base unit may be out of contact with the operating circuit of an aerial lift, for example, for a short period of time. Another scenario in which this may occur is if a base unit is powered by an auxiliary power circuit of an aerial lift with the auxiliary power circuit not being activated until the operator has been authenticated, for example, by a badge reader. In this case, a sensor module (which may be in a low power or deep sleep state that may be terminated, for example, when the operator manipulates a locked hook of the fall protection safety apparatus in the manner described above) may regain full operation and may detect that a proper connection from the locked hook to the operator's harness has been established, before the base unit regains full operation. A similar situation can develop in any instance in which a sensor module begins acquiring data (e.g., detects that a connection has been established) before a base unit is fully powered on, or before an aerial lift is fully powered on, regardless of the specific cause.

[0130] To enable more efficient operation of the fall protection monitoring system in the event of a loss or absence of communication, in some embodiments, a sensor module and/or a base unit may be configured to store data (of any type, including, for example, raw data, partially processed data, fully processed data, one or more first positive signals, status information on components or subsystems of the sensor module and/or base unit itself, and so on) onboard the sensor module and/or base unit. In some embodiments, such data may be stored onboard until communication is established or reestablished, at which point the stored data may be transmitted. (Similar arrangements may be provided in the case of communication over a telemetry network and communication interruptions thereof.)

Galvanically isolated connections

[0131] In some embodiments, it may be advantageous to use a wired connection between the base unit and the order picker control circuitry to send the at least one first positive signal (e.g., in analog form) from the base unit to the order picker control circuitry, rather than using a wireless/digital connection such as Bluetooth low energy. In some such embodiments, this may be done in a manner that galvanically isolates the base unit circuitry from the order picker control circuitry. By galvanic isolation is meant that there is no direct current flow between the base unit circuitry and the order picker circuitry.

[0132] A wired but galvanically isolated connection may be achieved by equipping the base unit 60 with a galvanic isolation interface 61 (shown in generic representation in Figure 1) through which the base unit may receive signals from a source outside the base unit (and, in some embodiments, may send signals to a destination outside the base unit) in a galvanically isolated manner. In an exemplary arrangement, a galvanic isolation interface may comprise a solid state relay that operates in conjunction with an input line (which will be referred to herein as line 1) from the order picker control circuit and an output line (which will be referred to herein as line 2) that returns from the base unit to the order picker control circuit. The order picker control circuit can be configured to send a constant voltage V (of any desired value, e.g. 1, 2, 4, 8, 16, 32 or 60 volts) along input line 1 to the solid state relay. Input line 1 will be maintained at this constant voltage V by the order picker control circuit. The solid state relay may be configured so that the sending of a first positive signal from the base unit to the order picker occurs, under certain circumstances, by means of the solid state relay assuming a “closed” configuration that allows the constant voltage signal V to be returned to the order picker on output line 2. In this manner, the solid state relay may comprise a so-called “normally open” switch that remains open (and thus does not allow the input voltage V on input line 1 to be returned to the order picker on output line 2) unless the base unit receives status information from the sensor module connector indicating that the connector appears to be properly connected to the user harness in the manner described hereinbefore. Upon receiving an indication that the connector appears to be properly connected, the solid state relay station (switch) will transition to the “closed” configuration in which it allows the input voltage V to be returned to the order picker. This voltage V, as returned to the order picker on output line 2, will be interpreted by the order picker circuit as being a first positive signal which (e.g. together with other positive signals) will cause the order picker circuit to enable at least the vertical movement function of the order picker.

[0133] In some convenient embodiments, a solid state relay as described above may rely on a so-called optoisolator, which comprises a light source (e.g., an LED) and a light detector (e.g., a photodiode or phototransistor). Briefly described, a suitable input signal (e.g., a “connected” signal from the sensor module) will cause the light source to emit light. The light detector will detect the light and cause the relay to transition to a configuration in which the voltage V can be returned along output line 2, without there being a direct electrical connection between the input signal and output line 2.

[0134] Equipping the base unit with a galvanic isolation interface may advantageously allow the fall protection monitoring system to be compatible with any order picker (or aerial lift in general), regardless of the voltages that the order picker's control circuitry may utilize. That is, a solid state relay as described herein may be capable of accepting any input voltage V along an input line 1 and returning that voltage V along an output line 2, regardless of the actual voltage value, so long as the voltage is in a suitable general range, e.g., 0 to 60 volts.

[0135] Many variations of the exemplary arrangements shown above are possible. For example, instead of a solid state relay being of the normally closed type as described above, the relay may be of a normally open type. In such an arrangement, the relay will remain in a closed configuration in which it receives an input voltage V on input line 1 and returns it to the order picker control circuit on output line 2, unless the base unit receives status information from the sensor module connector indicating that the connector appears to be properly connected to the user harness. If such an indication is received, the relay will now transition to an open configuration so that voltage V will no longer be returned to the order picker control circuit. In such a case, it is the cessation of a previously existing return voltage V that the order picker control circuit interprets as a first positive signal as previously mentioned. (Such a signal will therefore still be considered to be a “positive” signal as defined herein.)

[0136] In some embodiments, a solid state relay may be configured so that, rather than choosing between returning a voltage V (e.g., 7 volts) and “bouncing” a zero voltage signal across the output line, the relay may generally choose between returning a high voltage signal and a low voltage signal. In other words, the low voltage need not necessarily be exactly zero volts. Any system may be configured so that the high voltage corresponds to a positive first signal or so that the low voltage corresponds to a positive first signal. Various such arrangements are possible; all that is required is that the order picker control circuitry be configured to recognize which returned voltage corresponds to a positive signal, as defined herein, and which voltage corresponds to the absence of a positive signal.

[0137] In some embodiments, a base unit may comprise multiple solid state relays, each receiving an input voltage V, for example, along input line 1, and returning (or failing to return) it to the order picker along an output line. Thus, following the examples above, in some embodiments, a base unit may comprise a normally open solid state relay that will return a voltage V along output line 2 as a first positive signal. The base unit may comprise another normally closed solid state relay that will provide a supplemental first positive signal to the order picker, failing to return a voltage V along output line 3. In various embodiments, the control circuit of the order picker may be configured such that it receives a first positive signal on line 1, a first positive signal on line 2, or both, to activate the desired function(s) of the order picker. Having two (or more) of these complementary routes along which the first positive signals must be sent to enable the desired order picker function(s) can provide redundancy and robustness to the interlocking system.

[0138] In various embodiments, additional output lines may be provided for any desired purpose. Thus, in some cases, a base unit may be equipped with a multi-pin connector, e.g., a 2-, 4-, 8-, or 10-pin connector, for this purpose. (Such a multi-pin connector is an electrical connector and should not be confused with connector 30 which is a mechanical connector (i.e., a hook/loop).) Such a multi-pin connector on the base unit may be connected to a suitable electrical cable that is electrically connected to the control circuitry of the order picker such that at least one line of the cable and connector may serve as an input line that receives input from the order picker in the form of a constant voltage V, and such that at least one line may serve as an output line that may return the constant voltage V to the order picker. In various embodiments, one or more additional output lines may be dedicated to any of the system readiness parameters that have been described hereinbefore.

[0139]In an exemplary arrangement, a multi-pin connector and compatible electrical cable may be used to handle multiple first positive signals, with the connector and cable accommodating lines that are allocated as follows:

[0140]Line 1: Input line to receive constant voltage V from the order picker control circuit.

[0141]Line 2: Normally open switch output line to return constant voltage V to the order picker control circuit if the sensor module indicates that connector 30 appears to be connected to the harness.

[0142]Line 3: Normally closed switch output line to cease the return of constant voltage V to the order picker control circuit if the sensor module indicates that connector 30 appears to be connected to the harness. (Lines 2 and 3 are the type of complementary redundant output lines described above, noting that the order of the two output lines may be reversed if desired.)

[0143]Line 4: Output line to return (or not) the constant voltage V to the order picker depending on the results of a sensor module readiness check.

[0144]Line 5: Output line to return (or not) the constant voltage V to the order picker depending on the results of a base unit readiness check.

[0145]Line 6: Output line to return (or not) the constant voltage V to the order picker depending on the remaining evaluated life of the internal battery that powers the sensor module.

[0146]Line 7: Output line for returning (or not) the constant voltage V to the order picker depending on the results of a readiness check of an energy absorber of the fall protection device.

[0147] Still other lines, if available, may be dedicated to any use as desired. In various embodiments, other lines may be additional input lines, may be additional output lines, or may serve both purposes. In some embodiments, one or more lines may be GPIO (general purpose input/output) lines to be used for any desired purpose. In some embodiments, one or more lines may be configured to receive information from the order picker regarding the height to which the platform is currently elevated, e.g., for purposes discussed hereinbefore. One or more input and/or output lines may be configured to allow the fall protection monitoring system to interact with site telemetry, a central monitoring station, and so forth, without necessarily having to do so through the order picker operating circuitry. This may be used, for example, to provide a central monitoring station with information regarding the readiness and status of the fall protection apparatus and monitoring system.

[0148] The signals sent on lines 3 and above will correspond to various supplemental positive first signals as described hereinbefore. Other supplemental positive first signals may be used, for example, to interlock the vertical motion function of the order picker as a function of any other parameter monitored by the fall protection monitoring system. Although not specified in the examples above, lines 4 and above may be used with solid state relays comprising switches that are normally open, or normally closed, as desired. A normally open configuration, or a normally closed configuration, may be desired in various cases. Any first positive signals, including supplemental positive first signals, that are associated with a specific parameter (e.g., remaining battery life) may be sent in an arrangement that uses pairs of supplemental lines, for example, with one line operating through a normally open switch and another supplemental line operating through a normally closed switch (as with the exemplary lines 2 and 3 shown above). This can provide redundancy in monitoring and reporting on the specific parameter to which this signal pair is associated.

[0149] In the above exemplary arrangements, all output lines (i.e., line 2 through line 7 and any additional lines if present) operate from a single common input line 1. That is, an input voltage V arriving via a single input line 1 is returned, or not returned, on the multiple output lines. However, in some embodiments, one or more output lines may operate from a separate input line that is dedicated to operating with only that output line. It is also noted that in some embodiments (e.g., if the base unit and sensor module are integrated with each other), a combined self-check of both entities may be performed, and the combined results may be reported, such that only one output line may be required for such purpose. It is further noted that the line number designations (at least for the output lines) may be arbitrary designations in terms of the order and location of the actual physical lines.

[0150] The above discussions reveal that in some embodiments, a fall protection monitoring system may be configured to send (or not send) multiple positive signals to the control circuit of an order picker. In various embodiments, the total number of first positive signals may range from 1 to 4, 6, 8, 10, or more. As discussed hereinbefore, the order picker will also receive at least one additional positive signal from a safety apparatus of the order picker itself. Often, the order picker may receive, for example, two, three, four, or more of these additional positive signals (e.g., from an OPC key, a safety door, an operator authentication device, etc.). It will therefore be recognized that in some embodiments, the control circuit of an order picker may be configured to receive a number of positive signals, for example, up to 5, 10, 15, or even more. In many embodiments, the first positive signals described herein originating from the fall protection monitoring system may be input to the order picker control circuit in a manner similar to the additional positive signals originating from the order picker safety apparatus itself. For example, all such positive signals may enter the control circuit through a designated multi-pin connector or by any suitable arrangement of electrical cables, or the like.

[0151] It will be understood that although the detailed example presented above refers to a multi-channel wired connection, in other embodiments, wireless communication between a base unit and an aerial lift (accomplished by, e.g., short-range wireless, via a telemetry network, or via a cellular network) may equally involve multiple channels that allow multiple, e.g., independent, signals to be transmitted, received, and processed. Furthermore, the discussions above make clear that communication between any and all of a base unit, a sensor module, and an aerial lift may occur by any suitable method, whether by wire, by a short-range wireless arrangement such as, e.g., Bluetooth or Bluetooth LE, via a telemetry network, and/or via a cellular network. In some embodiments, one of these methods may be a primary method of communication with the other method being a backup method. (For example, a primary mode of communication between a base unit and an aerial lift may be via short-range wireless mode, with communication via a telemetry network to which the base unit and aerial lift belong, and/or communication may be via a cellular telephone network, serving as a backup, for example, with the system being configured to automatically switch to a backup communication method in the event of a problem with the primary communication method.)

[0152] The order picker control circuit may be configured to enable or disable various functions of the order picker based on the first positive signals (including first supplemental positive signals) and additional positive signals, taken as a set. In a simple exemplary arrangement, the control circuit may not enable the vertical movement function of the order picker unless all of the first positive signals and the expected additional positive signals are received. For example, if the control circuit is configured to (potentially) receive five first positive signals and three additional positive signals, the vertical movement function of the order picker may not be enabled unless all eight positive signals are received.

[0153] However, in some embodiments, the order picker control circuitry may include logic circuitry that allows more complex combinations of positive signals and the absence of positive signals to be taken into account when determining whether to enable various functions of the order picker. For example, if the order picker receives three specific first positive signals (and does not receive two other positive signals) and similarly receives two additional positive signals (and does not receive a third additional positive signal), one or more functions of the order picker may be enabled, while one or more other functions may be disabled.

[0154] Such logic circuits may be configured in any suitable manner, e.g., in the form of a look-up table encoding the desired Boolean logic (e.g., in the form of a truth table), by means of suitable logic gates and combinations thereof, decision trees, and so on. In some embodiments, such settings and configurations may be pre-installed in the order picker and be immutable. In other embodiments, at least some of such settings (e.g., dictating actions to be taken in terms of enabled and disenabled functions in response to a specific combination of received and non-received positive signals) may be user selectable and/or may be updated, e.g., by means of a firmware update to the order picker control circuitry.

[0155] The control circuitry of an aerial lift, e.g., logic circuits thereof, may be configured to handle more complex scenarios. Such scenarios may arise in a variety of circumstances, e.g., a training situation where an aerial lift is configured, e.g., with two SRLs so as to accommodate two operators. Other complex scenarios may arise in the case of an operator using two personal SRLs mounted on a harness (e.g., a dual-leg personal SRL arrangement, discussed in more detail later in this document), where only one of them may need to be detected as connected to an anchorage of the aerial lift at any given time. In some cases, quite complex scenarios may be present, e.g., in the case of a multi-occupant aerial lift (e.g., a high-capacity mobile elevating work platform, e.g., a large-capacity scissor lift) that may accommodate, e.g., up to six or more persons (and which may comprise a commensurate number of anchorages). Any scenario may be more complex, for example, if a fall protection monitoring system is configured to operate in cooperation with an operator authentication device (e.g., a badge reader) of the general type described hereinbefore. In such a case, the control circuit of the aerial lift (and/or the circuit in the fall protection monitoring system that determines whether to transmit one or more first positive signals) may be configured so that it must detect a number of connections (e.g., to the aerial lift anchorage) proportional to the number of persons identified by the operator authentication device as being present in the aerial lift in order to permit at least one vertical movement function of the aerial lift. It will be recognized that numerous and varied complex scenarios of these and other types may be envisaged. To accommodate such scenarios, the control circuits may include logic circuits equipped with one or more truth tables, as described above, and/or configured with one or more complex decision trees, sets of Boolean logic operators (e.g., AND, OR, NOT, NAND, NOR, XOR gates, and varieties and combinations thereof), and so on.

[0156] In some embodiments, the processing circuitry that makes decisions to enable or disable various functions of an aerial lift based on first positive signals (including first supplemental positive signals), additional positive signals, and so on, may be resident at a remote location, e.g., at a central monitoring station. Instructions may then be sent from that remote location to the aerial lift in accordance with the findings of the remotely located processing circuitry. However, in some embodiments, it may be preferable to have such decisions made locally, at the aerial lift itself, e.g., so that a temporary communication outage between the aerial lift and the central monitoring station will not affect the operation of the aerial lift. In some embodiments, the processing circuitry at a central monitoring station may be configured in parallel to that at the aerial lift, e.g., so that the central monitoring station may serve as a backup or may issue a notification in the event the backup circuitry detects a potential problem with the operation of the primary circuitry; or, in general, with any aspect of the aerial lift and its associated fall protection monitoring system.

[0157] It has been mentioned previously herein that if the fall protection safety apparatus comprises an energy absorber, in some embodiments, the energy absorber may be equipped with one or more sensors to detect, for example, whether any segments of the energy absorber become at least partially separated from one another, in order to provide an assessment of the readiness of the energy absorber. In some embodiments, arrangements of this general type may be used for a different purpose (whether or not such arrangements are also used for assessment of readiness). Specifically, in some embodiments, an energy absorber may be equipped with one or more sensors to provide an indication that a fall of the user may have occurred. For example, a sensor reading implying that a sufficiently large separation of the segments of a shock-pack type energy absorber has occurred may be taken as an indication of a possible fall of the user. Such an indication may be used to interlock at least the vertical lift function (and/or any other function) of the order picker in the general manner described above. This indication may also cause a notification to be issued (either transmitted locally and/or to a central monitoring station) that a possible user fall may have occurred.

[0158] If fall detection is desired, other sensors and sensing arrangements may be provided on various components of the fall protection apparatus, as appropriate. For example, one or more sensors may be configured to monitor the rotational speed and/or acceleration of the aforementioned spool 53 on which the lifeline 52 is wound. A sufficiently high observed speed and/or acceleration may be taken as an indication that a user fall may have occurred. Or a load cell or similar sensor may be used to monitor the load on the lifeline 52. The observation of a sufficiently high load may be taken as an indication that a user fall may have occurred. Any of the sensors described herein, alone or in any combination, may be used for such purposes. In some cases, the observation that a user fall may have occurred may also be taken as an indication that at least some component of the fall protection apparatus is no longer in a serviceable condition. Thus, performing detection for the purpose of detecting a possible fall of the user may have some overlap with performing detection to detect a readiness state of the fall protection device and the fall protection monitoring system.

[0159] In some embodiments, a sensor module of a fall protection monitoring system may be configured with one or more sensors that are capable of detecting more than just the presence or absence of an item or portion thereof. By way of specific illustration, such a sensor, as present on a connector, may be capable of doing more than simply reporting a yes/no indication of whether or not the connector appears to be attached to a detectable D-ring (e.g., metal). Instead, the sensor may be capable of providing an indication of whether the connector appears to be attached to a D-ring or appears to be attached to some other detectable item (e.g., a metal component of a docking station). Furthermore, such a sensor may be capable of distinguishing both situations in which the connector does not appear to be attached to any detectable item.

[0160] In some embodiments, such arrangements may be enhanced by equipping one or more designated items with an additional entity that is purposefully configured to alter the inductive signature of the item in a predetermined manner. With specific regard to inductive sensing, certain materials (e.g., ferrites) may be particularly suitable for purposes of altering the inductive signature of a metal item. Such materials may, for example, be arranged in a casing, a wrapper, a molded item, or the like, to form a complementary entity that may be, for example, mounted on, or otherwise disposed on, or proximate to, the metal item whose inductive signature is desired to be modified. Possible multimodal sensing and arrangements are thus discussed in detail in US provisional patent application 62/872545 and the resulting PCT patent application published as WO 2021/005467, both of which are incorporated herein by reference in their entirety.

[0161] Discussions thus far have focused on determining whether a connector appears to be connected to an aerial lift operator's harness by a combination of detecting the presence/absence of an item (e.g., a D-ring) in a hook opening and detecting the safe/unsafe state of a hook door. However, the general arrangements disclosed herein, in which an aerial lift is interlocked with a fall protection apparatus via a fall protection monitoring system, may be used with any detection method or combination thereof. For example, a detection system based on one or more cameras together with image processing circuitry may be capable of determining whether a connector of a fall protection apparatus appears to be connected to a D-ring of an aerial lift operator's harness versus, for example, hanging free from an SRL enclosure or engaged in an anchoring station. By “camera” is meant any suitable image acquisition device; Such a device is not necessarily limited to the acquisition of visible wavelength light, but may be configured, for example, to capture infrared radiation. Any suitable number of cameras may be used. In some embodiments, at least one such camera may be positioned generally behind the position where the user stands on the aerial lift operator support platform, such that the camera may obtain an unobstructed view of the dorsal D-ring of the operator's harness to determine whether the connector appears to be connected to the dorsal D-ring. Thus, for example, a camera may be positioned at a rear end of an overhead bulkhead 9 of the aerial lift, pointed generally forward and downward toward the general location where the dorsal D-ring would be expected to be encountered during normal use of the aerial lift.

[0162] In some embodiments, such a camera-based detection system may rely on markers (e.g., passive markers such as retroreflective marking symbols or active markers in the form of LEDs) provided on one or both of the connector of the fall protection apparatus and a D-ring of the user's harness. In other embodiments, a markerless system may be used. Any such detection system will comprise image processing circuitry that is configured to identify a connector, to identify a D-ring, and to verify that the connector appears to be connected to the D-ring. Here and elsewhere, terminology such as “connected to a D-ring” encompasses situations in which a connector of a fall protection device is directly connected to the D-ring, and also encompasses situations in which the connector is connected to an item (e.g., an extender) that is itself connected to the D-ring (noting further that, as emphasized hereinbefore, the term “D-ring” generically encompasses any suitable item that is attached to a user's harness such that a connector of a fall protection device can be connected thereto).

[0163] In some embodiments, such a camera-based detection system may be used as an accessory to, or as a replacement for, a sensor module of the general type described hereinbefore (comprising one or more sensors located on the connector itself). It should therefore be emphasized that the general arrangements disclosed herein for monitoring whether a connector of a fall protection apparatus appears to be connected to a harness of a user of an aerial lift are not necessarily limited to any one detection method or combination of detection methods. It may also be recognized that a fall protection monitoring system as disclosed herein (e.g., comprising a camera-based detection system) need not necessarily have any component that is mounted on, or directly connected to, the fall protection apparatus that the monitoring system is used to monitor. Rather, in some embodiments, some or all of the components of a monitoring system (e.g., a camera array and associated image processing hardware) may reside on the aerial lift rather than being installed on the fall protection apparatus itself.

[0164] In some embodiments, a camera-based detection system may be configured to serve as an operator presence control (OPC) switch of the general type described hereinbefore. (This may be the case regardless of whether the camera-based detection system also has the above-described function of monitoring whether the fall protection apparatus connector appears to be connected to the user's harness.) That is, one or more cameras and associated processing circuitry may be configured to verify whether a human user/operator is present on the operator support platform of the aerial lift, whether the operator appears to be standing upright, facing forward, etc. In other words, the detection system may provide an indication of whether the operator appears to be in an attentive posture that indicates that the operator is in a suitable condition to operate the aerial lift. Still further, the detection system may include at least one camera that generally faces the operator's face and serves, in conjunction with the associated circuitry, to monitor whether the operator has his or her eyes open.

[0165] Further, in some embodiments, such a detection system may comprise at least one thermal imaging camera (or, in general, an infrared sensor) that may provide an indication of whether the operator appears to have a fever. In some embodiments, such a detection system may comprise a motion capture functionality and may be configured to provide an indication of whether the operator is moving (or not moving) so as to indicate that the operator may be impaired, suffering from a medical condition, and so forth. Still further, in some embodiments, such a detection system may comprise at least one camera and associated circuitry that is configured to perform facial recognition in order to serve as an operator authentication device. Such an authentication device may be configured to identify a person who is standing on the operator support platform and, in particular, confirm that the person is trained and authorized to operate the aerial lift. The detection system may thus cause a tertiary positive signal to be sent to the order picker control circuitry that allows the aerial lift to be operated. And, in some embodiments, such a detection system may be configured to detect that two (or more) people are present on the operator support platform of an aerial lift, and provide such information to the control circuitry of the aerial lift, such that the aerial lift will accordingly enter a “multiple user” mode.

[0166] In a similar manner, a camera-based detection system (or, in general, any detection system, operating through any suitable mechanism) may be configured to verify that any person (e.g., a single operator) is present on the operator support platform 2. (Any such system may correspond to an operator detection module, as previously described herein.) In some embodiments, some of the functions described herein may be put on hold or otherwise not performed when an operator is not detected as being present. If an operator detection module is present, it may be used in combination with other systems for various purposes. For example, if an aerial lift is equipped to monitor its vertical elevation, and if an operator detection module reports that a user is no longer detected as being on the operator support platform at the time the lift is raised, the aerial lift (and/or the fall protection monitoring system) may issue a notification of a possible fall event. In various embodiments, an operator detection module may rely, for example, on one or more infrared sensors, ultrasonic sensors, LIDAR sensors, and so on, instead of, or as a complement to, a camera-based detection system.

[0167] In various embodiments, any of the arrangements described above or combinations thereof may be employed, noting that in many embodiments some or all of the cameras of such a system will typically reside on the aerial lift rather than on the fall protection apparatus. Thus, in various embodiments, an aerial lift may be provided with one or more camera-based detection systems that perform any or all of the functions of an OPC key, an operator authentication device, and so on, regardless of whether the camera-based detection system also serves as a fall protection monitoring system.

[0168] In some embodiments, the at least one sensor module of the fall protection monitoring system may comprise at least one sensor that is in the form of an accelerometer, e.g., a multi-axis accelerometer. In addition to other possible uses discussed hereinbefore, an accelerometer may augment the information obtained by the sensor previously discussed with additional information, e.g., as to the angle at which the connector is located, movements to which the connector is being subjected, and so on. In some circumstances, such additional information may, e.g., provide additional confirmation that the connector is, e.g., attached to a D-ring of a harness that is currently worn by the human user of the aerial lift. In other words, the attitude in which a connector is located and/or the movements that the connector undergoes may be useful in confirming that the connector is residing and/or moving in a manner that is characteristic of that expected when the connector is attached to a D-ring of a harness that is being worn by a person standing on the operator support platform. It is noted that such additional information may not be necessary in most situations and that the presence and use of an accelerometer in this manner should be considered an optional feature.

[0169] As previously noted, in some embodiments, a fall protection monitoring system may perform an additional function of transmitting one or more notifications. In some embodiments, this may be performed by a notification unit that is co-located with the base unit. In other embodiments, a notification unit may be provided that is separate from the base unit and located, for example, on a vertical wall of the aerial lift (or in some other readily visible location) and that may be instructed by the base unit to transmit a visible and/or audible notification. That is, in some embodiments, a notification unit may be separate from the base unit and may be present solely for the purpose of transmitting a notification rather than comprising any other functionality. Any notification unit may be configured (e.g., shaped and positioned) to ensure that it is readily visible but does not interfere with the order picker operator's view. Any of these notification units (comprising, for example, a series of LED lights) may be connected directly to the base unit, or the base unit may operate the wireless notification unit. It is not strictly necessary for an audible signal to be transmitted from the same location as a visible signal; thus, if desired, the monitoring system may comprise two physically separate notification systems, for example, an audible and a visible one.

[0170] Any such notification may be, for example, a “not ready” warning notification, meaning a notification that the safety appliance connector does not appear to be connected to the user’s harness. Or it may be a “ready” notification, meaning a notification that the connector appears to be connected to the user’s harness. Any such notification need not use specific words, such as, for example, “not ready”; rather, a notification may take any suitable form the meaning of which will be readily apparent to a trained user of the aerial lift and fall protection system.

[0171] In some embodiments, the base unit may be configured to transmit only a local notification (e.g., a visible signal and/or an audible signal). In some embodiments, the base unit may be configured to provide a notification to a remote unit, e.g., a smartphone or a central station or hub, at which the condition of various fall protection systems and/or aerial lifts may be monitored. Such arrangements may make use of any desired communication method, protocol, or the like, including any of those mentioned below. Of course, in various embodiments, any of the conditions that are monitored by the systems disclosed herein may be, e.g., logged, reported, e.g., to a central hub or monitoring station for tracking purposes, and so on. In particular, the fall protection monitoring system may, e.g., in response to a self-check, send a notification that some aspect or component of the monitoring system (or the fall protection apparatus) needs to be inspected, maintained, or serviced.

[0172] Any notification arrangement may be used in combination with any interlocking arrangement as described herein. For example, an order picker may be configured such that the order picker may be raised, e.g., up to 1 meter in the absence of a first positive signal indicating that the user's D-ring appears to be connected to a connector of the fall protection apparatus, but with the system issuing a notification when the order picker reaches, e.g., 0.5 meters in height. In some embodiments, the system may issue increasingly increasing warnings (e.g., lights that flash brighter, in a different color, and/or at a faster rate; audible signals of increasing volume, and so on) as the lifting height increases; in particular, as the height limit is approached. As discussed in detail here previously, once the order picker reaches the predetermined height limit, the interlock system will prevent the order picker from being raised any higher until the first positive signal(s) and additional appropriate positive signals are received.

[0173] In some embodiments, a fall protection system may optionally include a dedicated docking station to which connector 30 may be docked (i.e., connected) when not connected to the harness of a user of the aerial lift. In some embodiments, a docking station may be a separate entity from base unit 60. In other embodiments, a docking station may be integrated with base unit 60. In some embodiments, a docking station may be a purely mechanical apparatus that does not participate, either actively or passively, in the fall protection monitoring system. In other embodiments, a docking station may be configured (e.g., equipped with a sensor module) to participate in the fall protection monitoring system. That is, the presence of a docking station (either integrated into the base unit 60, or provided as a separate item in a separate location on the aerial lift) to which a connector 30 is to be fitted, provides another possible manner in which the condition of the connector can be monitored.

[0174] The discussions thus far in the present invention have primarily concerned SRLs comprising a cabinet that is attached to an overhead anchorage and comprising a lifeline that is extendable from the cabinet, with the distal end of the lifeline comprising a connector that can be connected to a D-ring of a harness worn by a user of an aerial lift. However, the arrangements disclosed herein may also be used with a so-called personal SRL (instead of the above, which may be called an overhead mounted SRL). By this is meant an SRL that comprises a cabinet that is attached to a user's harness and comprising a lifeline that is extendable from the cabinet, with the distal end of the lifeline supporting a connector that can be attached to an anchorage of the aerial lift. (With a personal SRL, the proximal end of the lifeline, which is connected, for example, to a drum or reel within the SRL enclosure, will be considered to be connected to the harness.) In this case, the descriptions of the present invention still apply, except that the monitoring system will be configured to determine whether the lifeline connector of the personal SRL appears to be connected to an anchorage rather than to the user's harness. All descriptions and discussions of the present invention may be adjusted accordingly. In some embodiments, a user's harness may be equipped with two personal SRLs (sometimes referred to as a two-leg arrangement or 100% tethering), for example, so that a person may remain tethered during the transition from an aerial lift to an elevated work platform. In this case, the connectors of both SRLs may be equipped with a sensor module and/or base unit.

[0175] An anchorage of an aerial lift configured for use with a personal SRL may take any suitable form, whether such anchorage is rigidly attached to the aerial lift (i.e., a component of the aerial lift itself), or takes the form of, for example, a D-ring on the end of a cable that is attached to the aerial lift. In some embodiments, such an anchorage may be suspended, for example, in the form of a cable that is attached to a bulkhead suspended from the aerial lift. However, in some embodiments (depending, for example, on the type and design of the particular aerial lift, the anchorage locations offered by the aerial lift, and so on), such an anchorage may be positioned, for example, at knee height or possibly below, noting that any anchorage and SRL must be positioned, configured, and used in compliance with all applicable laws, rules, codes, standards, and so on. In applying a monitoring system as disclosed herein to a personal SRL, the sensor module and the base unit of the monitoring system (whether as separate units or integrated together) may be disposed in any suitable location, whether at or near an anchorage, at a connector at the end of the SRL's lifeline, and so forth.

[0176] Most of the discussions thus far herein have focused on an arrangement in which a connector (e.g., a locked hook) at one end of a lifeline of an SRL is equipped with a sensor module (in some embodiments, with an integrated sensor module and base unit) configured to detect the presence of an item (e.g., a D-ring that is attached to a fall arrest harness, or an anchorage) that is captured by the connector. In various embodiments, such arrangements may be used with an overhead-mounted SRL, or with a personal SRL. In some embodiments, these arrangements may be reversed—that is, a sensor module may be situated, for example, on a D-ring or an anchorage, with a connector (e.g., a locked hook at one end of a lifeline of an SRL) being the item that is detected by the sensor module as the D-ring or anchorage is captured by the connector. In such arrangements, the descriptions and characterizations of the present invention still apply, with the connector, and the connected item, simply being exchanged.

[0177] Although the discussions herein have primarily addressed self-retracting lifelines (SRLs), it will be understood that the arrangements and methods disclosed herein may be applicable to any fall protection safety apparatus that is suitable for use with an aerial lift, e.g., an order picker. Such fall protection apparatus may take the form of, for example, a lifeline that is in the form of a webbing that is not necessarily extendable from, and retractable into, an enclosure in the manner of an SRL. Some such webbing may include products (often referred to as positioning straps) that provide fall restraint rather than fall arrest. It is thus emphasized that the arrangements and methods disclosed herein encompass fall protection apparatus that provide fall restraint, rather than being limited to, for example, fall protection apparatus only that provide fall arrest. In some embodiments, a strap may include at least one energy absorber (e.g., a tear strip or the like) configured to dissipate energy in the event of a fall; such straps are often referred to as energy absorbing straps. The arrangements and methods disclosed herein are therefore understood to apply, in various embodiments, to any of the same and to all such fall protection apparatus in general.

Aerial lifts

[0178] While the discussions herein have focused primarily on order pickers as a specific example of an aerial lift, it is emphasized that the arrangements and methods disclosed herein are applicable to any aerial lift (except for characterizations of features or modes of operation that do not apply to a particular type of aerial lift). Indeed, the terms aerial lift and order picker are used somewhat interchangeably herein. Accordingly, it will be understood that the descriptions and characterizations of the present invention apply to aerial lifts in general and to order pickers specifically (again, except for features or modes that do not apply to a particular type of aerial lift).

[0179] As disclosed herein, the term aerial lift encompasses any powered apparatus (e.g., powered by electric power, an internal combustion engine, a fuel cell, etc.) that comprises an operator-supporting platform (whether open, partially open, or closed) that can be moved in at least one generally vertical direction. In some embodiments (e.g., if the aerial lift is a forklift or dump truck), the platform may be movable in a horizontal direction and/or in an angular direction, rather than being limited to purely vertical movement. In many embodiments, the entire aerial lift may be capable of moving horizontally; for example, it may comprise a main body (e.g., a vehicle) that, in addition to supporting the vertically elevatable platform, is powered and can be steered in a horizontal direction.

[0180] In various embodiments, an aerial lift with which a fall protection apparatus and a fall protection monitoring system as disclosed herein may be used includes, in addition to the specific apparatus and categories already named, a so-called aerial work platform, a scissor lift, a reach truck (whether with a mobile carriage or mobile mast), a rotating reach truck, a tower truck, a powered narrow aisle truck (e.g., an industrial forklift equipped with an OSHA class II motor), and so forth. It is noted in particular that the aerial lifts with which the arrangements disclosed herein may be used are not limited to single-occupant aerial lifts (e.g., an order picker configured to hold a single operator) or even two-occupant aerial lifts, but may be used with multi-occupant aerial lifts, e.g., of the general type called aerial work platforms and mobile elevating work platforms. Some of these lifts as conventionally available may not necessarily comprise a suitable position (e.g., an overhead bulkhead) over which an anchorage for a suspended mounted SRL enclosure can be provided. In such cases, other arrangements (e.g., a personal SRL in combination with a suitable anchorage) or modifications may be used.

[0181] A fall protection monitoring system as disclosed herein may be provided and configured for use with an aerial lift in any suitable manner. This may involve any suitable combination of one or more components (e.g., a base unit) of the monitoring system being “permanently” installed in the aerial lift (e.g., being physically attached and connected to the aerial lift console), while one or more other components (e.g., a sensor module-equipped SRL) may be “permanently” or removably suspended from an overhead bulkhead of the aerial lift, e.g., by means of a cabin bracket or carabiner, the SRL being removable from the aerial lift in certain circumstances.

[0182] Such components may be installed on the aerial lift at any stage of the manufacture and transportation of the aerial lift or at the stage of preparation of the aerial lift for use that occurs at an end-use site of the aerial lift; furthermore, all components need not necessarily be installed on the aerial lift at the same time or at the same location. For example, the base units may be installed on the aerial lift at the factory where the aerial lift is manufactured. Or (particularly in the case of order pickers that are often used in large fleets that are maintained and serviced by special technicians) the base units may be installed on compatible aerial lifts at the end-use site.

[0183] Fall protection safety apparatus (e.g., SRLs) may be produced comprising connectors that are equipped with sensor modules, as disclosed herein; in some embodiments, such fall protection safety apparatus may be provided to the aerial lift manufacturer, who then dedicates a specific fall protection safety apparatus to a specific base unit-equipped aerial lift and ships them in combination to an end-use location. Or, in other embodiments, such a safety apparatus (e.g., an SRL) may be shipped directly to the end-use location and then installed on an aerial lift equipped with a specific base unit at the end-use location. In embodiments where the base units and sensor module-equipped fall protection safety apparatus are shipped in pairs of a base unit and a safety apparatus, each base unit and sensor module pair may be pre-paired wirelessly (e.g., via Bluetooth low energy) prior to being shipped (either to an aerial lift manufacturer or to an end-use location). Or, in some embodiments, the base units and sensor modules may be wirelessly paired with each other at the aerial lift manufacturer or end-use location (of course, the items may occasionally need to be wirelessly re-paired with each other at the end-use location, e.g., after a sensor module battery change, as noted hereinbefore).

[0184] In some embodiments, a base unit and a sensor module-equipped fall protection safety apparatus (e.g., an SRL) may not necessarily be shipped as a designated pair in the manner described above. Instead, in some embodiments, the base units and the sensor module-equipped fall protection safety apparatus may be shipped separately. It is noted that even if the base units and sensor module-equipped fall protection safety apparatus are shipped separately and are not paired with each other (either in the sense of being designated for the same aerial lift or in terms of wireless pairing), e.g., until they are at the end-use location, any such base units and sensor modules that are configured to operate together in the manner disclosed herein will be considered to form a fall protection monitoring system as claimed herein, regardless of whether or not they have already been assembled together on a particular aerial lift.

[0185] It has become clear from the above discussions that a fall protection monitoring system as disclosed herein may be configured in a number of different ways. Some arrangements (e.g., in which a connector of a fall protection apparatus is equipped with a sensor configured to detect a D-ring on a user's harness) may provide a “direct” indication that the connector appears to be attached to the D-ring, and thus may provide a direct indication that an aerial lift operator's harness appears to be connected to the fall protection apparatus's lifeline. Other arrangements may provide a direct indication of some other state of the connector (e.g., an SRL enclosure may be equipped with a sensor that is capable of providing a direct indication that the connector appears to be engaged against the SRL enclosure), and thus may provide an “indirect” indication that the connector does not appear to be connected to the operator's harness. It will be recognized, therefore, that the arrangements and methods disclosed herein may be used in a variety of forms and implementations, any of which may be used in combination.

[0186] It is emphasized that regardless of the operation of any monitoring system of a fall protection apparatus as disclosed herein, the user/operator of the aerial lift will be required to take any appropriate steps (e.g., as required by applicable laws, rules, codes, standards, and/or instructions), for example, to verify that the connector of the fall protection apparatus is securely attached to a properly placed fall protection safety harness. Under no circumstances shall the presence of any provision as disclosed herein relieve the operator of an aerial lift of the duty to follow all appropriate laws; rules; codes; standards as promulgated by applicable bodies (e.g., ANSI); instructions as provided by the manufacturer of the aerial lift; instructions as provided by the manufacturer of the fall protection system; instructions as provided by the entity responsible for a facility in which the aerial lift is used, and so forth.

[0187] It will be apparent to those skilled in the art that specific exemplary elements, structures, features, details, and configurations, among others, which are disclosed in the present invention, may be modified and/or combined in numerous embodiments. All such variations and combinations are contemplated by the inventor as being within the bounds of the conceived invention, not merely those representative drawings which have been chosen to serve as exemplary illustrations. Accordingly, the scope of the present invention is not to be limited to the specific illustrative structures described herein, but rather extends at least to those structures described by the language of the claims, as well as to equivalents of those structures. Any of the elements which are positively mentioned in this specification as alternatives may be explicitly included in the claims or excluded from the claims, in any combination, as desired. Any of the elements or combinations of elements that are reported in this specification in open language (e.g., “comprise” and derivatives thereof) are deemed to be additionally reported in closed language (e.g., “consist” and derivatives thereof) and in partially closed language (e.g., “consist essentially of” and derivatives thereof). To the extent there is any conflict or discrepancy between this specification as written and the disclosure in any document that is incorporated by reference herein but to which no priority is claimed, this specification shall control.

Claims (11)

1. A fall protection monitoring system for monitoring a fall protection safety apparatus comprising a safety line having a connector configured to be connected to a fall protection safety harness, the fall protection monitoring system comprising: a sensor module configured to determine whether the safety line connector of the fall protection safety apparatus appears to be connected to the fall protection safety harness and transmit connector status information based on whether the safety line connector of the fall protection safety apparatus appears to be connected to the fall protection safety harness; and a base unit configured to receive the connector status information from the sensor module; and if the connector status information indicates that the safety line connector of the fall protection safety apparatus appears to be connected to the fall protection safety harness, output a first positive signal; wherein the fall protection monitoring system is configured to perform at least one self-check of at least one component of the fall protection monitoring system, and wherein the base unit is configured such that if the self-check indicates that the at least one component of the fall protection monitoring system appears to be in a ready condition, the base unit will output at least one first supplemental positive signal. 2. The fall protection monitoring system of claim 1, the fall protection monitoring system being configured to perform self-checks of the first, second, and third components of the fall protection monitoring system, and wherein the base unit is configured such that if the self-checks indicate that the first, second, and third components of the fall protection monitoring system appear to be in a ready condition, the base unit will output at least three first supplemental positive signals. 3. The fall protection monitoring system of claim 2, wherein the first self-verified component of the fall protection monitoring system is the sensor module, the second self-verified component of the fall protection monitoring system is the base unit, and the third self-verified component of the fall protection monitoring system is at least one internal battery that powers at least one sensor module. 4. The fall protection monitoring system of claim 1 wherein the sensor module is located on the connector of the fall protection safety apparatus, and wherein the base unit is configured to be installed on an aerial lift with which the fall protection safety apparatus is configured to be used, with the sensor module being configured to wirelessly transmit status information from the connector to the base unit, and further wherein the base unit comprises a galvanic isolation interface configured such that the base unit can send the first positive signal and the at least one first supplemental positive signal to control circuitry of the aerial lift via a connection that is wired but that provides galvanic isolation between the base unit and the control circuitry of the aerial lift. 5. The fall protection monitoring system of claim 1 wherein the sensor module is located at the connector of the fall protection safety apparatus, wherein the base unit is co-located with the sensor module at the connector of the fall protection safety apparatus with the sensor module sending status information of the connector to the base unit via a wired connection; and wherein the base unit is configured to wirelessly send the first positive signal and the at least one first supplemental positive signal to the control circuit of an overhead lift with which the fall protection safety apparatus is configured to be used. 6. The fall protection monitoring system of claim 5, wherein the sensor module and the base unit are integrated with each other at the connector of the fall protection safety apparatus, and wherein the base unit comprises a short-range wireless radio configured to send the first positive signal and the at least one first supplemental positive signal to the control circuit of the aerial lift with which the fall protection safety apparatus is configured to be used. 7. The fall protection monitoring system of claim 1 wherein the sensor module comprises a sensor that is an RFID reader configured to detect the presence of an RFID tag disposed on a D-ring of a user's fall protection safety harness, the fall protection monitoring system being configured such that detection of the RFID tag by the sensor provides an indication that the safety line connector of the fall protection safety apparatus appears to be connected to the fall protection safety harness. 8. The fall protection monitoring system of claim 5, wherein the base unit is configured to wirelessly send the first positive signal and the at least one first supplemental positive signal to a telemetry network that is configured to forward the signals to the control circuit of an aerial lift with which the fall protection safety apparatus is configured to be used. 9. A method for controlling the operation of an aerial lift that is used in combination with a fall protection safety apparatus and a fall protection monitoring system, the method comprising: performing a self-check of at least one component of the fall protection monitoring system; upon receiving at least one first positive signal from the fall protection monitoring system indicating at least one connector of a safety line of the fall protection safety apparatus appears to be connected to a user's fall protection safety harness and receiving at least one first supplemental positive signal indicating that checking of the at least one component of the fall protection monitoring system shows that the at least one component of the fall protection monitoring system is in a ready condition, enabling at least one vertical movement function of the aerial lift; and upon the at least one first positive signal and/or the at least one first supplemental positive signal not being received, or failing to be received, disabling at least one vertical movement function of the aerial lift. 10. The method of claim 9 wherein the self-checks are performed on at least a first component of the fall protection monitoring system that is a sensor module, a second component of the fall protection monitoring system that is a base unit, and a third component of the fall protection monitoring system that is at least an internal battery that powers at least the sensor module, such that at least three first supplemental positive signals need to be received to enable at least the vertical movement function of the aerial lift and such that if any of the first three supplemental positive signals are not received or fail to be received, at least the vertical movement function of the aerial lift is disabled. 11. The method of claim 9, wherein the aerial lift comprises at least one additional safety apparatus in addition to the fall protection safety apparatus, and wherein for the at least one vertical movement function of the aerial lift to be enabled, the control circuit of the aerial lift needs to receive at least a first positive signal from the fall protection monitoring system indicating at least that the safety line connector appears to be connected to the user's safety harness, at least a first additional positive signal from the fall protection monitoring system indicating that verification of the at least one component of the fall protection monitoring system shows that the at least one component of the fall protection monitoring system is in a ready condition, and at least one additional positive signal from the at least one additional safety apparatus of the aerial lift indicating that the at least one additional safety apparatus is in a ready condition.