JP7386247B2 - Assistive device - Google Patents

Description

The present invention relates to an assistance device.

Patent Document 1 discloses an assistance device that assists a person being assisted in standing up and sitting down. The assistance device gradually lowers a support member that supports the upper body of the person being helped in an assistance process for assisting the person being helped to sit. As a result, the person being assisted is transferred from a standing posture to a sitting posture in which the buttocks are in contact with the seat surface. The assistance device controls the assistance process so that, for example, the assistance process is executed during a period in which the assistant is pressing the button.

International Publication No. 2018/116472

Here, depending on the clothes of the person being assisted and the condition of the seat, it may not be easy to visually determine whether the buttocks of the person being assisted, which are gradually lowering, are in contact with the seat or apart. . In the above case, it is not easy to determine whether or not the person being assisted is seated while the assistance process for assisting the person being assisted in sitting is being executed.

An object of the present specification is to provide an assistance device that is capable of detecting the seating of a person to be assisted during the execution of assistance processing for assisting the person to sit.

The present specification relates to an assistance device that performs assistance processing to assist the sitting motion of a person to be assisted, which includes a base, and is provided movably with respect to the base and supports the upper body of the person to be assisted. a support member; a load measuring device that measures the load that the support member supporting the person being assisted receives from the person being assisted; An assistance device is disclosed that includes a seating detection unit that detects whether the person being assisted is seated.

According to such a configuration, the load that the support member receives from the person to be cared for is measured, and based on the measurement result, it is detected whether the person to be cared for is seated while the assistance process is being performed. The detection result of the sitting position is particularly useful information because it is assumed that the result is used, for example, by a caregiver or a person being assisted to understand the operating state or to control the operation of an assisting device.

FIG. 2 is a side view showing an assistance device that supports a person being assisted in a sitting posture. FIG. 2 is a block diagram showing a controller, a load measuring device, and a control device of the assistance device. It is a perspective view which expands and shows the installed state of a load measuring device. FIG. 2 is a side view showing an assistance device that supports a person being assisted in an intermediate posture. FIG. 2 is a side view showing the assistance device in a standing support state that supports a person being assisted in a standing posture. It is a figure which shows the result of the load measurement in the assistance process of a seating motion. It is a flowchart which shows the first aspect of the detection process of the seated person of a cared person. It is a flowchart which shows the second aspect of the detection process of the seated person of a cared person. It is a flowchart which shows the third aspect of the detection process of the seated person of a cared person. FIG. 7 is a side view schematically showing the load measuring device in a modified form.

1. Configuration of Assistance Device 1 The configuration of the assistance device 1 of the embodiment will be described with reference to FIGS. 1 to 5. The assistance device 1 performs assistance processing to assist the person being assisted M (see FIG. 1, etc.) in getting up from a sitting position to a standing position, and assisting a person being assisted M (see FIG. 1, etc.) in getting up from a standing position to sitting down. Execute. By supporting the upper body of the person being assisted M in a standing posture by the assistance device 1, one caregiver can tow or otherwise move the assistance device 1 to a moving target in an assistance facility, for example.

Note that the "standing posture" means a posture in which the lower body of the person being assisted M is standing. In this specification, as shown in FIG. 5, the standing posture of the person being assisted M is a posture in which the buttocks Mt are raised from a sitting posture, the lower body is standing, and the upper body is leaning forward. That is, in the standing-up assistance process, the assistance device 1 assists the person being assisted M in the standing-up motion by raising the buttocks Mt and leaning the upper body forward to place the mass of the upper body on the assistance device 1. In addition, in the assistance process for the sitting operation, the assistance device 1 assists the person to be assisted M in the sitting operation to lower the position of the buttocks Mt.

The assistance device 1 includes a base 10, as shown in FIG. More specifically, the base 10 has a footrest 11 that is provided horizontally and close to the floor F. Both legs of the person being assisted M are placed on the footrest 11 . Note that the assistance device 1 may be configured without the footrest 11 depending on the level of assistance required by the person being assisted. The base 10 has an actuator support portion 12 that is provided upward on the front side of the upper surface of the footrest 11 . The actuator support section 12 rotatably supports the lower end of an actuator 30, which will be described later.

A pair of left and right front wheels 13 are provided at the lower front portion of the footrest 11. Furthermore, a pair of left and right rear wheels 14 are provided at the lower rear portion of the footrest 11. The front wheels 13 and the rear wheels 14 have a steering function to change the direction of movement. The front wheel 13 has a locking function to restrict movement of the assistive device 1. Due to the steering function of the front wheels 13 and rear wheels 14, the assistance device 1 is capable of not only moving forward and backward and changing direction, but also lateral movement (movement directly to the side) and super turning (turning on the spot). ing.

The assistance device 1 has a pair of left and right arm support parts 15 on the upper surface of the footrest 11 in front of the actuator support part 12 . The arm support section 15 rotatably supports the lower end of an arm 20, which will be described later. The assistance device 1 has a support rod 16 and a knee pad member 17. The support rod 16 extends upward from the footrest 11 and is bent so as to be inclined rearward and upward. The knee pad member 17 is provided at the upper end of the support rod 16 and is located above the front of the footrest 11.

The knee pad member 17 is a cushion material that extends in the left-right direction. The knees of the person being assisted M who are assisted in standing up and sitting down can come into contact with the knee rest member 17 . The knee pad member 17 is provided to stabilize the standing and sitting movements of the person M by determining the position of the knees of the person M.

The assistance device 1 includes an arm 20. The arm 20 is provided on the arm support portion 15 of the base 10 so as to be pivotable around a horizontal central axis 20A. In the initial state of the assistance device 1 (see FIG. 1), the arm 20 has a front arm portion 21 extending upward, and an upper arm portion 22 extending upward and rearward from the upper end of the front arm portion 21. The overall shape is L-shaped. The arm 20 has a bracket 23 to which a support member 50, which will be described later, is attached. The bracket 23 is rotatably provided at the rear end of the upper arm 22 around a horizontal rotation axis 20B.

The assistance device 1 includes an actuator 30. The actuator 30 rotates the arm 20 and tilts the support member 50 with respect to the arm 20 in the assistance process. In this embodiment, the actuator 30 is an extendable and retractable actuator. The actuator 30 has a main body portion 31, a movable portion 32, and a motor 33. The main body portion 31 is rotatably supported by the actuator support portion 12 of the base 10 at its lower end. The main body portion 31 is formed into a cylindrical shape with an open upper end.

The movable part 32 of the actuator 30 is formed into a columnar shape having a diameter smaller than that of the main body part 31, and is fitted into the inner peripheral side of the main body part 31. The upper end of the movable portion 32 is rotatably attached to a link mechanism 40, which will be described later. The motor 33 is attached to the lower front side of the main body portion 31 . The power supply state of the motor 33 is controlled by a control device 80, which will be described later, and moves the movable portion 32 in the extending direction with respect to the main body portion 31. Note that the actuator 30 can use another type of drive source, such as a pressure drive source using hydraulic pressure or air pressure, instead of the motor 33.

The assistance device 1 includes a link mechanism 40. The link mechanism 40 converts a portion of the telescopic movement of the actuator 30 into a rotational movement of the bracket 23 with respect to the arm upper part 22. The link mechanism 40 includes a first link member 41, a second link member 42, and a regulating member 43. The first link member 41 is rotatably supported around a first support shaft 41A provided on the arm upper part 22. The first link member 41 is rotatably connected to the upper end of the movable part 32 of the actuator 30 on the front side of the first support shaft 41A shown in FIG. 1 around the connection shaft 41B.

The first link member 41 also has an engagement pin that is formed to protrude in the left-right direction at an end on the rear side of the first support shaft 41A shown in FIG. 411 is provided. The second link member 42 is rotatably supported around a second support shaft 42A provided on the arm upper part 22. In this embodiment, the second support shaft 42A is coaxial with the rotating shaft 20B of the bracket 23. The front end of the second link member 42 is located below the engagement pin 411 of the first link member 41. A rear end portion of the second link member 42 is fixed to the bracket 23.

When the first link member 41 rotates counterclockwise around the first support shaft 41A, the second link member 42 rotates clockwise so that its front end is pushed down by the engagement pin 411. At this time, the second link member 42 and the bracket 23 rotate integrally with respect to the arm upper part 22 around the second support shaft 42A (rotation shaft 20B). The regulating member 43 is fixed to the arm 20 at a position above the first link member 41 and in contact with the rotating first link member 41 . Note that in the state shown in FIG. 1, a gap is formed between the first link member 41 and the regulating member 43.

The assistance device 1 includes a support member 50 that supports the upper body of the person being assisted. The support member 50 is attached to the bracket 23 and is provided movably with respect to the base 10 via the arm 20. In this embodiment, the support member 50 includes a torso support section 51, a pair of side support sections 52, and a base plate 53. The torso support portion 51 is formed in a planar shape similar to the shape of the torso of the person being assisted. The body support portion 51 is formed integrally with the base plate 53 using a material that can be flexibly deformed. The support surface of the torso support part 51 comes into surface contact with the front surface of the torso of the upper body of the person being assisted M to support the torso. More specifically, the support surface of the torso support section 51 supports the range of the person being assisted M from the chest to the abdomen.

A pair of armpit support sections 52 are provided on the left and right sides of the trunk support section 51 and support the armpits of the person being assisted. Further, the armpit support section 52 is swingably supported by the torso support section 51. The side support portion 52 is formed into an L-shape by a rod-shaped member. The surface of the side support portion 52 is covered with a material that can be flexibly deformed. The base plate 53 is made of a material such as metal or resin. The base plate 53 is supported together with the bracket 23 with respect to the arm upper part 22 so as to be freely tiltable in a direction in which the second link member 42 is separated from the engagement pin 411. Thereby, the support member 50 is configured to be tiltable within a predetermined angular range clockwise in FIG. 1 from the state shown in FIG. 1 with respect to the main body of the arm 20 (arm front portion 21 and arm 22). The above-mentioned "free tilting" means not tilting driven by an actuator or the like, but tilting that can be moved manually.

The assistance device 1 includes a handle 55. The handle 55 is formed into a generally rectangular frame shape. The handle 55 is formed to extend forward and upward from the upper end of the bracket 23. The side portions of the handle 55 are held by both hands of the person being assisted. Furthermore, the lateral and front parts of the handle 55 are grasped by the caregiver to move the assistance device 1.

The assistance device 1 includes a controller 60 that receives operations from the person being assisted M or the assistant. The controller 60 includes a stand-up button 61 and a seat button 62, as shown in FIG. The stand-up button 61 accepts a request for assistance in a stand-up motion. The seating button 62 accepts a request for assisting the seating operation.

The assistance device 1 includes a load measuring device 70. The load measuring device 70 measures the load that the support member 50, which supports the person being assisted, receives from the person being assisted. In this embodiment, the load measuring device 70 includes a strain gauge 71 that measures the amount of strain in the object to be measured. The above measurement target is a part of the arm 20 that connects the base 10 and the support member 50 or the actuator 30 that drives the arm 20, and when the support member 50 receives a load from the person M, the strain It is set to the part where this occurs.

In this embodiment, the object to be measured is a measured object 72 that extends approximately parallel to the arm front section 21, as shown in FIG. The object to be measured 72 is arranged so as to connect the lower end and the upper end of the arm front section 21. The shape and position of the measured object 72 are appropriately set so that when the support member 50 receives a load from the person being assisted M, the measured object 72 deforms more than the arm front part 21 according to the load applied to the arm 20.

The assistance device 1 includes a control device 80 that executes assistance processing. The control device 80 includes a storage device 81 and an operation control section 82, as shown in FIG. The storage device 81 is configured with a flash memory or the like. The storage device 81 stores a control program used when the assistance device 1 executes assistance processing and operation history data Dm in which an operation history is recorded. The operation control unit 82 controls the operation of the actuator 30 and moves the support member 50 that supports the person being assisted.

In the present embodiment, the motion control unit 82 performs the standing-up assistance process on the assumption that there is a request for assistance in the standing-up operation, for example, during a period in which the stand-up button 61 of the controller 60 is pressed. Furthermore, during the period in which the sitting button 62 is pressed, the motion control unit 82 executes the sitting operation assistance process, assuming that there is a request for assistance with the sitting operation. Note that the assistance device 1 may receive an assistance request via a pedal that accepts the foot operation of the assistant or a microphone that inputs the voice of the assistant or the like.

The control device 80 includes a seating detection section 83. The seating detection unit 83 detects the seating of the person to be assisted M during the execution of the assistance process based on the measurement result by the load measuring device 70 . Here, "sitting of the person being assisted M" that is detected when the assistance process for sitting motion is executed means a completed state in which the person being assisted M has shifted to a sitting position by executing the assistance process, and a state in which the person being assisted M has transitioned to a sitting position due to the execution of the assistance process, and Accordingly, at least one of the intermediate states from when the buttocks Mt of the person being assisted Mt comes into contact with the seat surface Sf until the transition to the completed state is defined as the assisted person M being seated.

The above completed state is a state in which the mass of the person being assisted M is mainly supported by the seat surface Sf and the footrest 11, and in other words, the person being assisted M is able to detach from the support member 50. Further, the intermediate state is a state in which the buttocks Mt of the person being assisted M are in contact with the seat surface Sf, although the completed state has not been reached, and at least a portion of the mass of the person being assisted M is supported by the seat surface Sf. It is.

In this embodiment, the seating detection unit 83 uses the detected value of the strain gauge 71 provided on the object to be measured 72 whose strain amount varies depending on the load applied to the support member 50 as the result of the load measurement by the load measuring device 70. Enter as . Further, in this embodiment, the detection result by the seating detection unit 83 includes the degree of progress of the assistance process. Details of the seating detection process by the seating detection unit 83 will be described later.

The assistance device 1 includes a notification device 90. The notification device 90 notifies the outside of the detection result by the seating detection section 83. In this embodiment, the notification device 90 notifies a caregiver who operates the assistance device 1 to assist the person being assisted M of the detection result. Various modes can be adopted for notification by the notification device 90. The notification device 90 may notify the assistant of the detection result by at least one of sound, display, and vibration.

Specifically, the notification device 90 may sound a buzzer to notify by sound, for example, according to the detection result by the seating detection section 83. The above-mentioned buzzer may also serve as a buzzer for notifying the remaining amount of the battery (not shown) used to drive the actuator 30, or a dedicated buzzer may be provided. Further, when a display device is provided outside the cover (not shown) that covers the arm 20, the notification device 90 may notify the detection result by displaying the detection result on the display device.

Furthermore, when a vibration device is built into the controller 60 or the handle 55, the notification device 90 may drive the vibration device according to the detection result by the seating detection section 83 to notify by vibration. Further, the notification device 90 may notify the detection result using a combination of sound, display, and vibration, or may notify the detection results by switching them depending on the settings of the assistant or the like. Furthermore, the notification device 90 may vary the volume, tone, display content, vibration pattern, and vibration intensity according to the detection results.

Here, as described above, the sitting detection unit 83 detects the completed state in which the person being assisted M has shifted to the sitting posture, or the intermediate state just before that, as the person being assisted M being seated. Furthermore, the detection result by the notification device 90 may include the degree of progress of the assistance process. In the above configuration, the notification device 90 may notify a completion state, an intermediate state, or a transition state before the intermediate state as a detection result. Further, the notification device 90 may change the notification mode depending on the degree of progress of each state.

2. Assisting process for standing up motion by the assisting device 1 The assisting process for assisting the standing up motion by the assisting device 1 will be described with reference to FIGS. 1, 4, and 5. When providing assistance using the assistance device 1, the assistance device 1 is set in an initial state in front of the person being assisted. The initial state of the assistance device 1 is a state in which the support member 50 is lowered as shown in FIG. 1 and the person to be assisted M can appear. The vertical position of the support member 50 can be adjusted to some extent by pressing the stand-up button 61 or the seat button 62.

Further, in the initial state of the assistance device 1, the actuator 30 is in a state where the entire movable range is generally shortened. At this time, a gap is formed between the first link member 41 and the regulating member 43. When the assistance device 1 is set on the front side of the person being assisted, the person being assisted M moves his or her lower legs under the support member 50 and places both legs on the footrest 11 . Next, the person being assisted M leans his or her torso forward so that the chest is in surface contact with the torso support section 51, and both sides are supported by the armpit support section 52. A caregiver may assist the person being assisted M in the series of operations described above.

In the initial posture in which the person being assisted M gets on the assistance device 1 as described above, the buttocks Mt of the person being assisted M are on the seat surface. Therefore, the person being assisted M in the initial posture is in a posture where the weight is supported by the buttocks Mt and both legs. Subsequently, when the assistant presses the stand-up button 61, the assistance device 1 executes a standing-up assistance process. Specifically, the motion control unit 82 drives the actuator 30 to extend. As a result, the first link member 41 rotates counterclockwise around the first support shaft 41A, as shown by the arrow in FIG. As the first link member 41 rotates, the engagement pin 411 pushes down the front end of the second link member 42 .

Thereby, the second link member 42 and the bracket 23 rotate integrally clockwise around the second support shaft 42A (rotation shaft 20B). As a result, the support member 50 attached to the bracket 23 tilts forward while supporting the upper body of the person being assisted. This operation continues until the actuator 30 extends to a predetermined length and the first link member 41 contacts the regulating member 43. As a result, the person being assisted M is shifted to an intermediate posture in which the upper body is tilted forward, as shown in FIG.

Further, in FIG. 4, the first link member 41 comes into contact with a regulating member 43, and rotation about the first support shaft 41A is regulated. That is, the first link member 41, the second link member 42, and the support member 50 are restricted from moving relative to the arm 20, and move integrally with the arm 20 during the transition operation. After that, the motion control unit 82 drives the actuator 30 to further extend. As a result, the arm 20 receives a driving force via the first link member 41 and the regulating member 43, and rotates clockwise about the central axis 20A, as shown by the arrow in FIG.

As the arm 20 rotates, the actuator 30 tilts forward with respect to the base 10. The support member 50 that supports the upper body of the person being assisted M rotates around the central axis 20A together with the arm 20 and the link mechanism 40. As a result, the support member 50 moves forward and upward, and raises the upper body of the person being assisted while further leaning forward. As a result, the person being assisted M is moved to a standing posture in which the buttocks Mt are largely separated from the seat surface Sf and both legs are extended. Note that the operation control unit 82 executes the above operation during a period when the stand-up button 61 is pressed by the caregiver and the support member 50 is within the movable range.

3. Assistance Processing for Sitting Movement by Assistive Device 1 Assistance processing for assisting sitting movement by the assisting device 1 will be described with reference to FIGS. 1, 4, and 5. Here, the mechanical operation of the assistance device 1 in the assistance process for sitting down corresponds to the reverse order of the assistance process for standing up. Therefore, the mechanical operation of the assistance device 1 will be briefly explained below. When the caregiver presses the seat button 62 while the person being assisted M in the standing posture is riding on the assistance device 1 (see FIG. 5), the motion control unit 82 starts the assistance process for the sitting motion. .

Then, until the actuator 30 is shortened to a predetermined length, the support member 50 rotates counterclockwise around the central axis 20A together with the arm 20 and the link mechanism 40. As a result, the person being assisted M is transferred from the standing posture to the intermediate posture (see FIG. 4). After that, when the actuator 30 is further shortened, the first link member 41 separates from the regulating member 43 and rotates clockwise around the first support shaft 41A. Accordingly, the movement of the second link member 42 and the support member 50 rotates counterclockwise around the second support shaft 42A (rotation shaft 20B).

As a result, the buttocks Mt of the person being assisted M gradually descends and approaches the seat surface Sf, and eventually comes into contact with the seat surface Sf. Furthermore, when the actuator 30 is shortened, the person being assisted M becomes in a state where the buttocks Mt are supported by the seat surface Sf, and shifts to a sitting posture in which the upper body can be separated from the support member 50 (see FIG. 1). ). Note that the operation control unit 82 executes the above operation during a period when the seat button 62 is pressed by the caregiver and the support member 50 is within the movable range. Further, the motion control unit 82 may adopt a control mode in which the movement of the support member 50 is stopped or decelerated in accordance with the detection result by the seating detection unit 83, which will be described later, in addition to the operation by the assistant. can.

4. Seating detection processing by the seating detection unit 83 4-1. Outline of seating detection processing The seating detection processing performed by the seating detection section 83 will be described with reference to FIGS. 6 to 7C. Here, in assisting the sitting movement using the assistance device 1, the caregiver visually confirms, for example, that the posture of the person being assisted M, particularly the buttocks Mt, has come into contact with the seat surface Sf and that the person has completely transitioned to a sitting posture. and stops pressing the seat button 62. As a result, the support member 50 stops moving downward.

However, if the clothes of the person being assisted M are loose enough for their body shape, or if the seat surface Sf is made of soft material, the buttocks Mt of the person being assisted M, which gradually descends, may come into contact with the seat surface Sf. It may not be easy to visually determine whether the object is near or far away. Furthermore, if the place where the sitting movement is assisted is small, such as in a toilet room, it may not be easy for the caregiver to peer into the buttocks Mt of the person being assisted Mt and the seat surface Sf.

In view of the above circumstances, a configuration that can detect whether the person being assisted M is seated makes it possible to notify the caregiver of the detection result and to reflect it in the operation control of the assistance process. Useful. In addition, from the perspective of improving the manageability of the assistance device 1, the operation history of what kind of operations the assistance device 1 has received and how it has been driven is also updated to show whether or not the person being assisted M is seated. A configuration that allows detection of seating is useful.

Therefore, the assistance device 1 of the present embodiment adopts a configuration that can detect the seating of the person being assisted M during the execution of the assistance process for assisting the person being assisted M in sitting. Specifically, the assistance device 1 includes a load measuring device 70 that measures the load that the support member 50 receives from the person being assisted M, and a seating detection unit 83 that detects whether the person being assisted M is seated while the assistance process is being performed. Equipped with As an example, the load measuring device 70 may have a configuration including the strain gauge 71 and the object to be measured 72 as described above.

The load measuring device 70 converts the load applied to the support member 50 into the amount of strain of the measured object 72 that deforms in accordance with the load applied to the arm 20 during execution of the assistance process. Then, the load measuring device 70 measures the load that the support member 50 receives by measuring this amount of distortion. For example, when the sitting motion assistance process is executed, the load measuring device 70 obtains a measurement result in which the load varies with time, as shown in FIG. 6 . Specifically, at time T1, when the assistant presses the seating button 62 to start the assistance process for the sitting operation, the load applied to the arm 20 gradually increases.

Then, at time T2, when the buttock Mt of the person being assisted M comes into contact with the seat surface Sf and the person is in an intermediate sitting state, the load that the support member 50 receives begins to decrease. Along with this, the load applied to the arm 20 gradually decreases. Thereafter, the person being assisted M is mainly supported by the seat surface Sf and reaches a completed seating state, and when the person being assisted M separates from the support member 50 at time T4, the load applied to the arm 20 returns to the initial state.

The seating detection unit 83 detects the seating of the assisted person M, including the degree of progress of the assistance process, based on the measurement results by the load measuring device 70 (see FIG. 6) during the execution of the assistance process for the sitting motion. Execute processing. Here, according to the load measuring device 70, the load applied to the arm 20 exhibits characteristics as shown in FIG. Therefore, the seating detection unit 83 may detect seating based on, for example, a change in the increase or decrease of the load at time T2, or simply when the magnitude of the load becomes equal to or less than a reference value.

On the other hand, the actual load measurement value is influenced by noise, the amount of force applied to the legs by the person being assisted, the weight and physique of the person being assisted, and the height and flexibility of the seat Sf. It is expected that this will be received. In this case, in the above-mentioned mode, there is a possibility that the seating detection accuracy is not sufficient. Therefore, the seating detection unit 83 detects the seating of the person to be assisted M in the following three ways, with one purpose of improving the detection accuracy of the sitting.

4-2. First aspect of the sitting detection process In the first aspect of the sitting detection process, the sitting detection unit 83 detects the sitting of the person being assisted M based on the temporal fluctuation of the load measured by the load measuring device 70. . Specifically, as shown in FIG. 7A, the seating detection unit 83 first calculates the reduction rate Rc per unit time of the load measured by the load measuring device 70 (S11). The above-mentioned "unit time" is a time that can be set arbitrarily, and is set depending on the resolution of the strain gauge 71, for example. The reduction rate Rc corresponds to the average value of the amount of reduction in load per unit time, and as shown in FIG. 6, it is regarded as the angle formed by the tangent line and the vertical line at a predetermined time of the curve showing the temporal fluctuation of load. be able to.

Next, the seating detection unit 83 determines whether the calculated current reduction rate Rc exceeds a preset reference reduction rate Rs (S12). This standard reduction rate Rs is a value that can be arbitrarily set, and is set to be equal to or smaller than the expected load reduction rate when the buttock Mt of the person being assisted Mt contacts the seat surface Sf, for example. be done. If the current reduction rate Rc does not exceed the reference reduction rate Rs (S12: No), the seating detection unit 83 determines that the buttocks Mt of the person being assisted M is at a higher position than the seat surface Sf, and performs S11 and Repeat S12.

If the current reduction rate Rc exceeds the reference reduction rate Rs (S12: Yes), the seating detection unit 83 calculates the time for which this state is maintained (maintenance time Wm) (S13). Specifically, the seating detection unit 83 starts timer measurement when the current reduction rate Rc first exceeds the reference reduction rate Rs, and sets that time as the maintenance time Wm. The seating detection unit 83 determines whether the maintenance time Wm exceeds a certain period Ws (for example, corresponding to the time from time T2 to time T3 in FIG. 6) (S14).

If the maintenance time Wm does not exceed the fixed period Ws (S14: No), the seating detection unit 83 detects that although there is a possibility that the buttocks Mt of the person being assisted M are in contact with the seat surface Sf, Since there is a possibility that this has not been achieved, steps S11 to S14 are repeated. If the maintenance time Wm exceeds the fixed period Ws (S14: Yes), the seating detection unit 83 detects that the current reduction rate Rc has been maintained in a state exceeding the reference reduction rate Rs for a certain period or more (FIG. 6 As the first transition C1), it is assumed that the person being assisted M is seated (S15).

4-3. Second Aspect of Seating Detection Process In the second aspect of the seating detection process, similarly to the first aspect, the occupancy detector 83 determines whether the person to be assisted is on the basis of temporal fluctuations in the load measured by the load measuring device 70. The seating of person M is detected. Specifically, as shown in FIG. 7B, the seating detection unit 83 first calculates the reduction rate Rc per unit time of the load measured by the load measuring device 70 (S21). Next, the seating detection unit 83 determines whether the current reduction rate Rc falls within a preset reference fixed range Rm (S22).

The reference fixed range Rm mentioned above can be set arbitrarily. For example, the lower limit of the reduction rate in the standard constant range Rm may be set to a value of the load reduction rate that does not exceed even if there is noise or the person being assisted M applies force to the legs, or even if it is set larger than that value. good. Further, the upper limit of the rate of decrease in the reference fixed range Rm may be set by taking into account, for example, the measurement characteristics of the strain gauge 71, or may not be set substantially. If the current reduction rate Rc does not fall within the reference fixed range Rm (S22: No), the seating detection unit 83 determines that the person being assisted M is not seated and repeats S21 and S22.

On the other hand, if the current reduction rate Rc falls within the reference constant range Rm (S22: Yes, second transition C2 in FIG. 6), the seating detection unit 83 considers that the person being assisted M is seated (S23). . In the second aspect, by appropriately setting the "unit time" in S21 and the reference constant range Rm in S22, for example, the initial, middle, and final stages of the intermediate state of sitting (the state from time T2 to time T4 in FIG. 6) can be detected as sitting.

4-4. Third Aspect of Seating Detection Process In the third aspect of the seating detection process, the seating detection unit 83 detects the care recipient M by comparing the load measured by the load measuring device 70 with a preset threshold Th. Detect seating. Specifically, as shown in FIG. 7C, the seating detection unit 83 first executes a process of setting the threshold Th (S31). The above-mentioned threshold Th may be a fixed value, but it may be set dynamically each time the assistance process is executed, since it may cause false detection due to variations in the weight of the person being assisted M or the mass of the replaced support member 50. It is preferable to do so.

The seating detection unit 83 is configured, for example, at the start of the standing up motion (the state shown in FIG. 1), during the standing up motion (for example, the state shown in FIG. 4), and at the end of the standing up motion (the same as at the start of the sitting motion, FIG. The threshold value Th is set based on the maximum value, minimum value, average value, etc. of the load measured in the state). Specifically, the seating detection unit 83 sets a predetermined ratio of the maximum value LM of the load during execution of the standing-up motion assistance process to the threshold Th. The above maximum value LM roughly matches the maximum value LM in FIG. The above-mentioned "predetermined ratio" can be set to about 90%, for example, using the same concept as the lower limit of the reference fixed range Rm in the second aspect. Note that the symbol "Lm" in FIG. 6 indicates the minimum value Lm of the load Vd.

Next, the seating detection unit 83 determines whether the current load Vd measured by the load measuring device 70 is less than the threshold Th (S32). If the current load Vd is not below the threshold Th (S32: No), the seating detection unit 83 repeats the comparison between the current load Vd and the threshold Th (S32). On the other hand, if the current load Vd is less than the threshold Th (S32: Yes), the seating detection unit 83 considers that the person being assisted M is seated (S33). Note that the seating detection unit 83 may set a plurality of threshold values and detect seating by considering the time period during which the current load Vd remains below the threshold value, as in the first aspect.

The seating detection unit 83 may employ any of the first to third aspects of the detection processing described above, or may employ a composite combination of these. Further, the mode of detection processing may be changed as appropriate depending on the configuration and usage mode of the assisting device 1. Thereby, the detection accuracy of seating can be further improved.

5. Utilization of Detection Results by Seating Detection Unit 83 The use of detection results by the occupancy detection unit 83 as described above will be described. Here, the sitting detection unit 83 detects the sitting of the person to be assisted M in the assistance process for assisting the sitting motion using the assistance device 1. Further, this seating of the person being assisted M includes a completed state in which the person being assisted M shifts to a sitting posture, or an intermediate state just before that. Further, as described above, the seating detection unit 83 may also detect the degree of progress of the assistance process including before reaching the intermediate state. The assistance device 1 can utilize the detection result by the seating detection section 83 in the following three ways.

5-1. First Mode of Utilization of Detection Results In a first mode of use of detection results, the control device 80 notifies the outside of the detection results. Specifically, when the seating is detected, for example, the control device 80 causes the notification device 90 to emit a buzzer sound to notify the assistant who operates the assistance device 1 . Thereby, the caregiver can recognize that the person being assisted M is mainly supported by the seat Sf without looking into the buttocks Mt of the person being assisted Mt and the seat Sf.

Here, conventionally, since it is uncertain whether or not the person M is seated completely depending on the clothing of the person being assisted M and the flexibility of the seat surface Sf, the caregiver may have to In some cases, the operation was continued to lower the support member 50. Such a situation increases the time required for assistance processing. On the other hand, according to the aspect described above, the assistant can recognize whether or not the support member 50 has been sufficiently lowered based on the notification from the notification device 90, and can appropriately terminate the assistance process.

Further, in the first mode of using the detection results, the detection results may be notified by various notification modes (at least one of sound, display, and vibration) employed in the notification device 90. In addition, according to the notification mode using display or vibration, it is possible to have a configuration in which only the assistant is notified of the detection result, for example. Furthermore, the notification device 90 may switch the volume, tone, display content, vibration pattern, and vibration intensity depending on the degree of progress of the assistance process. Thereby, the caregiver and the person being assisted M can recognize the current state and that the assistance device 1 is operating.

5-2. Second Mode of Utilization of Detection Results In a second mode of use of detection results, the control device 80 reflects the detection results in movement control of the support member 50 . Specifically, when the seating detection unit 83 detects that the person to be assisted M is seated, the control device 80 stops the movement of the support member 50 with respect to the base 10 and ends the assistance process. In other words, whereas conventionally the control device 80 basically executes the assistance process during the period when the seat button 62 is pressed by the assistant's operation, the control device 80 executes the assistance process based on the result that the sitting is detected. Stops automatically.

According to such a configuration, after the assistant presses the seat button 62, for example, the assistant can appropriately execute the assistance process simply by continuing to press the seat button 62 until the assistance device 1 automatically stops. As a result, the caregiver pays close attention to whether the positional relationship between the person being assisted M and the seat surface Sf is appropriate during the sitting motion, or whether the person being assisted M is being supported by the support member 50 in an appropriate posture. becomes possible. As a result, safety can be improved.

Further, the control device 80 does not stop the movement of the support member 50 as described above, but moves the support member 50 relative to the base 10 when the sitting detection unit 83 detects that the person being assisted M is seated. The assistance processing may be continued by decelerating the speed. Here, conventionally, the moving speed of the support member 50 is constant from the start to the end of the assistance process, and is appropriately set, for example, in consideration of safety after seating is completed. Therefore, the moving speed of the support member 50 in the assistance process for the sitting operation is generally set to a low speed as a whole.

On the other hand, if the movement of the support member 50 is decelerated when seating is detected, while ensuring the above-mentioned safety, for example, it is possible to reduce the speed from the start of the assistance process for the sitting operation until reaching the intermediate state of sitting. It becomes possible to set the moving speed of the support member 50 during the period to be higher than before. Thereby, the time required for assistance processing can be shortened. As a result, the burden on the person being assisted M and the caregiver can be reduced.

Note that a combination of deceleration and stopping of the support member 50 as described above may be employed. Specifically, depending on the degree of progress of the assistance process, for example, the support member 50 is decelerated when the buttocks Mt of the person to be assisted M comes into contact with the seat surface Sf, and the support member 50 is stopped when the seating is completed. You can also use it as Furthermore, the notification mode by the notification device 90 may also be changed according to a change in the moving speed of the support member 50.

5-3. Third aspect of utilization of detection results In a third aspect of utilization of detection results, the control device 80 detects the position of the support member 50 with respect to the base 10 at predetermined intervals by the seating detection unit 83 during execution of the assistance process. The results are associated and recorded as the operation history of the assistance device 1. Specifically, the control device 80 updates the operation history data Dm so that the detection result is included.

As a result, in addition to the operation history related to the operation control of the actuator 30 by the operation control unit 82, the operation of the controller 60 by the caregiver, the detection values from various sensors (not shown), and the like, the detection results by the seating detection unit 83 are recorded in association with each other. be done. Note that the values detected by the above-mentioned sensors include the measurement results by the load measuring device 70.

According to such a configuration, traceability of the assistance device 1 can be improved. Therefore, for example, when the assistance device 1 does not normally complete the assistance processing for standing up motion and sitting motion, the cause of the abnormal motion can be easily identified based on the motion history data Dm. Furthermore, by analyzing the operation history data Dm, it is possible to obtain the number of execution times and execution timing of assistance processing using the assistance device 1, the time required for each, appropriateness of operation, skill level, etc. As a result, the manageability of the assistance device 1 can be improved.

The control device 80 of the assistance device 1 may adopt any of the first to third aspects of the use of the detection results described above, or may adopt a composite combination of these. Furthermore, the manner in which the detection process is used may be appropriately switched depending on the configuration and manner of use of the assisting device 1. In this way, in the assistance process for assisting the person being assisted M to sit down, it is particularly useful to detect the sitting position of the person being assisted M.

6. Variations of embodiment 6-1. Regarding the load measuring device 70 In the embodiment, the load measuring device 70 is configured to include a strain gauge 71 that measures the amount of strain in the object to be measured (for example, the object to be measured 72). On the other hand, the load measuring device 70 may detect the load using a configuration different from that of the strain gauge 71. For example, as shown in FIG. 9, the load measuring device 170 may include a displacement mechanism 171 and a displacement sensor 172.

Here, in the embodiment, the base plate 53 is configured to rotate integrally with the bracket 23 around the second support shaft 42A (rotation shaft 20B). In this embodiment, the base plate 53 is further provided to be rotatable about the rotation axis 53A with respect to the bracket 23. That is, in this embodiment, the support member 50 is configured to rotate around the rotation axis 53A with respect to the arm 20 and to be freely tiltable in a direction in which the base plate 53 is separated from the bracket 23.

The displacement mechanism 171 is provided on the arm 20 that connects the base 10 and the support member 50. Specifically, the displacement mechanism 171 is provided on the bracket 23 of the arm 20. The displacement mechanism 171 displaces at least a portion of the support member 50 with respect to the arm 20 according to the load that the support member 50 receives. Specifically, the displacement mechanism 171 includes a pusher 171A and an elastic body 171B.

The pusher 171A of the displacement mechanism 171 is provided on the bracket 23 so as to be movable toward the base plate 53 of the support member 50 facing the bracket 23. The elastic body 171B urges the pusher 171A from the bracket 23 toward the base plate 53. In the initial state of the assistive device 1, the pusher 171A is in a state where it protrudes most from the bracket 23, and its tip portion contacts and supports the base plate 53.

Here, when the support member 50 receives a load from the person M, the base plate 53 presses the pusher 171A toward the bracket 23 against the urging force of the elastic body 171B. At this time, in FIG. 9, the support member 50 rotates counterclockwise around the rotating shaft 53A. In other words, the displacement mechanism 171 displaces at least a portion of the support member 50 (for example, a portion of the base plate 53 that contacts the pusher 171A) with respect to the arm 20 according to the load that the support member 50 receives.

The displacement sensor 172 measures the amount of displacement of the support member 50 due to the operation of the displacement mechanism 171. Specifically, the displacement sensor 172 is provided on the bracket 23 and measures the amount of displacement of the support member 50 based on the amount of movement of the pusher 171A that is pressed against the base plate 53 and moves. Moreover, the above displacement amount can be regarded as the load that the support member 50 receives from the person being assisted M during the execution of the assistance process for the sitting operation, from the relationship with the spring constant set to the elastic body 171B.

According to such a configuration, it is possible to detect whether the person being assisted M is seated in the same way as in the embodiment. In addition to the above, the load measuring device 170 having the displacement mechanism 171 and the displacement sensor 172 may adopt various modes as long as the load applied to the support member 50 can be directly or indirectly measured. I can do it.

Note that in this embodiment, the base plate 53 is configured to be rotatable with respect to the bracket 23. On the other hand, in the configuration in which the base plate 53 rotates integrally with the bracket 23 around the second support shaft 42A (rotation shaft 20B) as in the embodiment, the displacement mechanism 171 is provided on the first link member 41, for example. It's okay to be hit. Specifically, the displacement mechanism 171 urges the second link member 42 with the pusher 171A so that the second link member 42 separates from the engagement pin 411. Alternatively, the engagement pin 411 may be movably provided in the first link member 41, and the engagement pin 411 may also serve as the pusher 171A.

In the above embodiment, the load measuring device 170 measures the amount of movement of the pusher 171A with respect to the first link member 41 using the displacement sensor 172. Then, the load measuring device 170 measures the amount of displacement of the support member 50 based on the measurement result of the displacement sensor 172. Furthermore, the load measuring device 170 measures the load that the support member 50 receives from the person being assisted M during the execution of the sitting motion assistance process based on the amount of displacement of the support member 50 . Such a configuration also provides the same effects as the embodiment.

6-2. Others In the embodiment, the assistance device 1 is configured to include one actuator 30 and a link mechanism 40. On the other hand, the assistance device 1 may have a configuration including a multi-jointed arm 20 and a plurality of actuators, or a configuration including a lifting device that raises and lowers the arm 20 with respect to a base. In either configuration, the assistance device 1 includes a load measuring device 70, 170 that can directly or indirectly measure the load that the support member 50 receives from the person being assisted.

At this time, it is assumed that the characteristics of the measured load may differ from those shown in FIG. 6 depending on the configuration of the assisting device 1 and the location of the load measuring devices 70, 170. However, by capturing temporal fluctuations in the load during the execution of the assistance process taking into consideration the configuration of the assistance device 1, the seating detection unit 83 can detect the assistance recipient M including the degree of progress of the assistance process, as in the embodiment. It is possible to detect the seating of the person.

1: Assistance device, 10: Base, 20: Arm, 30: Actuator, 40: Link mechanism, 50: Support member, 60: Controller, 61: Stand-up button, 62: Seating button, 70, 170: Load measuring device, 71: Strain gauge, 72: Measured object, 171: Displacement mechanism, 172: Displacement sensor, 80: Control device, 81: Storage device, 82: Operation control section, 83: Seating detection section, 90: Notification device, M: Assisted person, Mt: Buttocks, F: Floor surface, Sf: Seat surface, Rs: Standard decrease rate, Rc: (Current) decrease rate, Rm: Standard constant range, C1: First transition, C2: Second transition , Th: threshold value, Dm: operation history data

Claims (10)

An assistance device that performs assistance processing for assisting a person being helped in sitting motion, the assistance device comprising:
The base and
a support member that is movably provided with respect to the base and supports the upper body of the person being assisted;
a load measuring device that measures the load that the support member that supports the person being assisted receives from the person being assisted;
a seating detection unit that detects whether the person to be assisted is seated during execution of the assistance process based on a measurement result by the load measuring device;
Equipped with
The seating detection unit detects a first transition in which a reduction rate per unit time of the load measured by the load measuring device is maintained in a state exceeding a preset reference reduction rate for a certain period or more, and the reduction rate. The assistance device detects whether the person to be assisted is seated based on at least one of the second transitions in which the transition falls within a preset reference constant range. The sitting detection unit is configured to detect a completed state in which the person being assisted moves to a sitting posture by executing the assistance process, and a state in which the person being assisted moves to the completed state after the buttocks of the person being assisted come into contact with a seat surface by executing the assistance process. The assistance device according to claim 1 , wherein at least one of the intermediate states before the transition is detected as the assistance recipient being seated. The load measuring device is a part of an arm that connects the base and the support member or an actuator that drives the arm, and is a part where distortion occurs when the support member receives a load from the person being assisted. The assistance device according to claim 1 or 2 , further comprising a strain gauge for measuring the amount of strain of the measurement object. The load measuring device includes:
a displacement mechanism that is provided on an arm that connects the base and the support member, and that displaces at least a portion of the support member with respect to the arm according to a load that the support member receives;
The assistance device according to any one of claims 1 to 3 , further comprising a displacement sensor that measures the amount of displacement of the support member due to the operation of the displacement mechanism. The assistance according to any one of claims 1 to 4 , wherein the sitting detection unit detects whether the person being assisted is sitting by comparing the load measured by the load measuring device with a preset threshold value. Device. The assistance device further includes a notification device that notifies a caregiver who operates the assistance device to assist the person to be assisted of the detection result by the seating detection unit. The assistance device according to item 1. The assistance device according to claim 6 , wherein the notification device notifies the assistant of the detection result by at least one of sound, display, and vibration. The detection result by the seating detection unit includes the degree of progress of the assistance process,
The assistance device according to claim 6 or 7 , wherein the notification device changes a notification mode depending on the degree of progress in the detection result. 9. The assistance device continues the assistance process by decelerating the movement of the support member relative to the base when the sitting detection unit detects that the person being assisted is seated. The assistance device according to item (1) . The assisting device associates the detection result by the seating detection unit with the position of the support member with respect to the base at predetermined intervals during execution of the assisting process, and records the result as an operation history of the assisting device. The assistance device according to any one of 1-9.

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