JP7664062B2 - Transport robot - Google Patents

Description

One embodiment of the present invention relates to a transport robot that transports a loading platform equipped with casters.

The technology for automatic transport robots is being developed, and they are being used in a variety of situations. For example, a transport robot has been developed that can slip under a platform with casters and transport objects with the casters raised above the floor (see, for example, Patent Document 1).

JP 2019-59460 A

The transport robot disclosed in Patent Document 1 cannot be made taller because it crawls under the loading platform. This creates the problem that if there is a step in the path the transport robot is moving through, the casters will hit the step and the robot will not be able to get over it. Furthermore, if the transport robot tries to force its way over the step, the loading platform will tilt, causing the load to collapse and ultimately causing the loading platform to tip over.

In view of these problems, one embodiment of the present invention aims to provide a transport robot that can move smoothly even over steps.

The transport robot according to one embodiment of the present invention is a transport robot that transports a platform with casters, and includes a vehicle body that slides under the platform of the transport platform cart, a lift device that is provided on the vehicle body and lifts the platform of the transport platform cart, a traveling device that drives the vehicle body, an inclination sensor that detects the inclination of the vehicle body, and a step detection sensor that detects a step in the direction of travel of the vehicle body. The transport robot has a mechanism that supports the platform of the transport platform cart horizontally using the lift device when climbing over a step.

According to one embodiment of the present invention, the transport robot is equipped with a sensor that detects steps, and when going over a step, the lift device controls the height of the platform of the transport cart, allowing the robot to go over the step in a stable manner. This makes it possible to prevent the load on the transport cart from collapsing or tipping over.

1A to 1C are diagrams showing a transfer robot according to an embodiment of the present invention, in which FIG. 1 shows a system configuration of a transport robot according to an embodiment of the present invention. 1A and 1B are diagrams illustrating the operation of a transport robot according to an embodiment of the present invention, in which (A) shows a side view at a stage before climbing over a step, and (B) shows a front view at that stage. 1A and 1B are diagrams illustrating the operation of a transport robot according to an embodiment of the present invention, in which FIG. 1A shows a side view of the stage of climbing up a step, and FIG. 1A and 1B are diagrams illustrating the operation of a transport robot according to an embodiment of the present invention, in which FIG. 1A shows a side view of the stage of descending a step, and FIG. 1B shows the stage after descending the step. 1A and 1B are diagrams illustrating the operation of a transport robot according to an embodiment of the present invention, in which FIG. 1A shows a side view of the stage of climbing up a step, and FIG. 1B shows the stage after climbing up the step. 1A to 1C are diagrams showing a transfer robot according to an embodiment of the present invention, in which FIG. 1A and 1B are diagrams illustrating the operation of a transport robot according to an embodiment of the present invention, in which (A) shows a side view of the stage of climbing up a step, and (B) shows a front view when climbing up the step.

The following describes the embodiments of the present invention with reference to the drawings. However, the present invention can be implemented in many different ways, and should not be interpreted as being limited to the description of the embodiments exemplified below. In order to clarify the explanation, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention. In this specification and each figure, elements similar to those described above with respect to the previous figures may be given the same reference numerals, and detailed explanations may be omitted as appropriate. Furthermore, the letters "first" and "second" attached to each element are convenient labels used to distinguish each element, and have no further meaning unless otherwise specified.

[First embodiment]
This embodiment describes the configuration and operation of a transport robot that transports a loading platform.

1. Configuration of the Transport Robot Figures 1 (A) to (C) show a transport robot 100 according to an embodiment of the present invention. The transport robot 100 according to this embodiment has the function of slipping under the platform of a transport cart and transporting the transport cart. Figure 1 (A) shows a plan view of the transport robot, (B) shows a side view, and (C) shows a front view. The transport robot 100 includes a vehicle body 102, a traveling device 104, a lift device 106, and a step detection sensor 108.

1-1. Vehicle Body The shape of the vehicle body 102 is arbitrary, but the overall height is kept low so that it can get under a loading platform with casters. In Figures 1 (A) to (C), the vehicle body 102 is a rectangular box shape in plan view, and has a tapered shape at the front and rear lower ends when viewed from the side. The vehicle body 102 is provided with a lift device 106 and a step detection sensor 108, and inside it are housed a drive mechanism 110 that constitutes part of the traveling device 104, a controller 112, an inclination sensor 114, a communication device 116, and a power source (not shown).

1-2. Traveling Device The traveling device 104 includes a pair of crawler units 118 (first crawler unit 118a, second crawler unit 118b) provided on both sides of the vehicle body 102, and a drive mechanism 110 provided inside the vehicle body 102 for driving the crawler units 118. The crawler units 118 (first crawler unit 118a, second crawler unit 118b) are configured to include an endless belt-like crawler belt 120, a drive wheel 122 arranged on one end side of an area surrounded by the crawler belt 120, an idler wheel 124 arranged on the other end side, and a roller 126 between the drive wheel 122 and the idler wheel 124. The drive wheel 122 has a sprocket shape (not shown) and transmits power to the crawler belt 120 by rotating while being connected to an axle extending from the drive mechanism 110.

The drive mechanism 110 includes a motor and gears, and transmits power independently to the first crawler unit 118a and the second crawler unit 118b, which are arranged on the left and right sides of the traveling direction (the direction of the arrows shown in Figures 1 (A) and (B)). The drive mechanism 110 can rotate the drive wheels 122 clockwise and counterclockwise by combining a motor and gears. The transport robot 100, equipped with a running device 104 configured in this way, can move forward and backward, turn right and left, and rotate on its own axis.

1-3. Lift Device The lift device 106 is mounted on the vehicle body 102. The lift device 106 includes a plurality of lifters 128. Fig. 1(A) shows a first lifter 128a and a second lifter 128b disposed on the left and right sides forward from the center of the vehicle body, and a third lifter 128c and a fourth lifter 128d disposed on the left and right sides rearward from the center of the vehicle body. The operations of the first lifter 128a, the second lifter 128b, the third lifter 128c, and the fourth lifter 128d are individually controlled by lifter driving units (not shown).

The lifters 128 (first lifter 128a, second lifter 128b, third lifter 128c, fourth lifter 128d) have a shaft 130 that extends upward from the upper part of the vehicle body 102. A support 132 that abuts against the bottom surface of the loading platform may be provided at the tip of the shaft 130. The lifter 128 is, for example, a cylinder (or actuator) that operates hydraulically or pneumatically. The lift device 106 has the function of lifting the loading platform from below and controlling its height by each of the lifters 128 (first lifter 128a, second lifter 128b, third lifter 128c, fourth lifter 128d) extending upward. The first lifter 128a, second lifter 128b, third lifter 128c, and fourth lifter 128d have their shafts 130 independently controlled for raising and lowering.

As shown in FIG. 1(A), by providing lifters 128 in four locations, the loading platform can be supported at four points, and the loading platform can be raised and lowered in a stable manner. Note that, although FIG. 1(A) shows an example in which lifters 128 are provided in four locations, this is not limiting, and a greater number of lifters may be provided on the vehicle body 102. Furthermore, the multiple lifters 128 may be provided in a total of three locations, two in the front and one in the rear, or one each in the front and rear.

1-4. Step detection sensor The step detection sensor 108 is provided at the front of the vehicle body 102. The step detection sensor 108 has a function of detecting whether or not a step exists in the traveling direction of the transport robot 100. An optical sensor is used as the step detection sensor 108. For example, a displacement sensor, a shape measurement sensor, or the like is used as the optical sensor. Since the transport robot 100 can move forward and backward, the step detection sensor 108 may be provided not only at the front of the vehicle body 102 but also at the rear.

The step detection sensor 108 may also be configured to capture an image of the area ahead of the transport robot 100 in the direction of travel with a camera and detect steps through image analysis. For example, steps may be recognized using image recognition technology based on artificial intelligence.

The step detection sensor 108 may be provided both at the front and rear of the vehicle body 102. That is, a first step detection sensor 108a may be provided at the front of the vehicle body 102, and a second step detection sensor 108b may be provided at the rear. The first step detection sensor 108a can be used to detect a step in the traveling direction of the transport robot 100, and the second step detection sensor 108b can be used to detect when the transport robot 100 has overcome the step.

1-5. Tilt Sensor The vehicle body 102 is preferably provided with a tilt sensor 114. The tilt sensor 114 is used to detect the tilt of the vehicle body 102 when the transport robot 100 overcomes a step. The tilt sensor 114 is preferably capable of detecting the tilt in the front-rear direction and the left-right direction of the vehicle body 102. As the tilt sensor 114, for example, a capacitance type tilt sensor can be used.

2. System Configuration of the Transport Robot Fig. 2 shows the system configuration of the transport robot 100. The transport robot 100 is composed of a CPU (Central Processing Unit), memory, an interface, etc., and is controlled by a controller 112 that operates according to a program in which commands to control the operation of each part are written. Commands for starting the transport robot 100, setting a movement path, etc. are sent from a host computer, and the sent commands are received by a communication device 116 and input to the controller 112. The transport robot 100 outputs a signal that controls the operation of a drive mechanism 110 based on the path information sent from the host computer.

A signal from the step detection sensor 108 is input to the controller 112. When a step is detected by the signal output from the step detection sensor 108, a command to control the operation of each lifter 128 in the lift device 106 as described in the next section is output to the lifter drive unit 117. A signal from the tilt sensor 114 is also input to the controller 112. The controller 112 outputs a command to the lifter drive unit 117 to control the operation of each lifter 128 so that the loading platform is kept level based on the signal from the tilt sensor 114.

In this way, the transport robot 100 detects information about the route along which the robot will actually move using the step detection sensor 108, detects the state of the vehicle body 102 using the tilt sensor 114, and the controller 112 controls the operation of the lift device 106 based on this information. In other words, when the transport robot 100 detects a step along the route of movement, it drives the lift device 106 so that the platform being transported is not obstructed by the step, and also has the function of driving the lift device 106 so that the platform being transported does not tilt when the vehicle body 102 tilts.

3 to 5, the operation of the transfer robot 100 will be described. In the following description, a step 300 exists in the moving direction of the transfer robot 100, and the transfer robot 100 overcomes the step.

Figures 3(A) and (B) show the stage when the transport robot 100 detects a step 300 ahead in the direction of travel while transporting the platform 202 with casters 204. Note that Figure 3(A) shows the transport robot 100 and the transport cart 200 as seen from the side, and (B) shows them as seen from the front.

As shown in Figures 3(A) and (B), the transport robot 100 is under the platform 202, and the shaft 130 of the lifter 128 is raised so that the receiving platform 132 is in contact with the underside of the platform 202. The receiving platform 132 has a friction surface on its surface, and is in contact with the platform 202 so as not to slip due to the force of the lifter 128 pressing against the platform 202 from below. The casters 204 of the transport cart 200 are in contact with the floor, and the transport robot 100 can transport the transport cart 200 by itself. Baggage 206 may be placed on the platform 202 of the transport cart 200.

The transport robot 100 detects the step 300 in front of it in the direction of travel by the step detection sensor 108. The transport robot 100 can overcome the step 300 because the running device 104 is composed of the crawler unit 118, but the loading platform 202 may collide with the step 300 and be unable to overcome it because it is transported with the casters 204 on the ground. Even if the casters 204 can get on the step 300, if the front wheels get on the step 300 first, the loading platform 202 may tilt and the load may collapse. Furthermore, if the casters 204 on the front wheels of the loading platform 202 are in front of the transport robot 100, if the casters 204 get on the step 300 first, the receiving platform 132 of the front lifter 128 may move away from the loading platform 202, which will cause a problem that the loading platform 202 cannot be transported in a stable state.

To prepare for such an event, the transport robot 100 stops just before the step 300 and performs an operation to lift the platform 202 using the lift device 106. That is, the transport robot 100 performs an operation to lift the casters 204 to the height T of the step 300 using the lift device 106. Figure 4 (A) shows the state in which the transport robot 100 stops just before the step 300 and the platform 202 is lifted horizontally.

When the transport robot 100 moves forward in this state, the casters 204 can make contact with the top surface of the step 300, and the platform 202 can be maintained in a horizontal state. The height of the step 300 can be detected by the step detection sensor 108. The transport robot 100 operates the lift device 106 to lift the platform 202 by the height of the step 300, using the function of the controller 112. The transport robot 100 then moves forward with the platform 202 lifted horizontally.

Figure 4 (B) shows the stage where the transport robot 100 climbs up the step 300. When the crawler unit 118 climbs up the step 300, the front part is lifted and the vehicle body 102 tilts diagonally backward. If this state is left as it is, the loading platform 202 will also tilt backward. However, when the transport robot 100 climbs up the step 300 and the vehicle body 102 tilts, the tilt sensor 114 detects the tilt, and the controller 112 has a function of controlling the lift device 106 to keep the loading platform 202 horizontal. Specifically, the shafts of the rear third lifter 128c and fourth lifter 128d are extended relative to the front first lifter 128a and second lifter 128b to keep the loading platform 202 at a constant height and maintain the horizontality. In addition, the shafts of the first lifter 128a and the second lifter 128b at the front may be lowered, and the shafts of the third lifter 128c and the fourth lifter 128d at the rear may be raised to maintain the platform 202 at a constant height and level. Since the inclination angle of the vehicle body 102 changes as the transport robot 100 advances, the lift device 106 is dynamically controlled based on the signal of the inclination sensor 114.

Figure 5 (A) shows the stage where the transport robot 100 descends the step 300. Since the vehicle body 102 also tilts when descending the step 300, the lift device 106 is controlled to keep the platform 202 horizontal. The transport robot 100 is controlled to extend the shafts of the front first lifter 128a and second lifter 128b relative to the rear third lifter 128c and fourth lifter 128d to maintain the platform 202 at a constant height while maintaining the horizontality. In addition, the shafts of the rear third lifter 128c and fourth lifter 128d may be lowered and the shafts of the front first lifter 128a and second lifter 128b may be raised to maintain the platform 202 at a constant height while maintaining the horizontality. In this case, the inclination angle of the vehicle body 102 changes as the transport robot 100 advances, so the lift device 106 is dynamically controlled based on the signal of the inclination sensor 114.

Figure 5 (B) shows the state after the transport robot 100 has passed over the step 300. The transport robot 100 detects that it has passed over the step 300 with the second step detection sensor 108b located at the rear, and performs an operation of lowering the first lifter 128a, the second lifter 128b, the third lifter 128c, and the fourth lifter 128d to ground the casters 204 on the floor.

In this way, the transport robot 100 can climb up or overcome the step 300 while lifting the loading platform 202 horizontally by individually controlling the multiple lifters 128 of the lift device 106 in accordance with the inclination of the vehicle body 102.

According to this embodiment, the transport robot 100 is equipped with a sensor that detects steps, and when going over a step, the lift device 106 controls the height of the platform of the transport cart, allowing the transport robot 100 to go over the step in a stable manner. This makes it possible to prevent the load on the transport cart 200 from collapsing or tipping over. By having the functions shown in this embodiment, the transport robot 100 can select various transport routes, thereby expanding the range of movement of the transport robot 100.

Second Embodiment
This embodiment shows another example of the operation performed when the transport robot 100 shown in the first embodiment overcomes the step 300.

Figure 6 (A) shows the stage where the transport robot 100 climbs up onto the step 300. At this stage, as described with reference to Figure 4 (B), the transport robot 100 controls the lift device 106 to extend the shafts of the rear third lifter 128c and fourth lifter 128d relative to the front first lifter 128a and second lifter 128b.

In this embodiment, instead of lifting the platform 202 horizontally in this state, the platform 202 is controlled to tilt forward. The angle θ at which the lift device 106 tilts the platform 202 forward is preferably in the range of 1 to 3 degrees. By tilting the platform 202 forward in this way, a load can be applied to the front casters 204 (front wheels) of the transport cart 200, thereby improving stability.

Figure 6 (B) shows the stage where the transport robot 100 has climbed up onto the step 300. At this stage, the transport robot 100 controls the lift device 106 to return the inclination of the loading platform 202 to its original position and make it horizontal. In this case, the rear third lifter 128c and fourth lifter 128d are lowered. If necessary, the front first lifter 128a and second lifter 128b are simultaneously raised. If the loading platform 202 is left tilted forward, the transport robot 100 may lean forward when descending the step 300 and may not be able to maintain stability. The transport robot 100 can ensure stability by returning the loading platform 202 to a horizontal position before descending the step 300.

According to this embodiment, even if the transport robot 100 hits a step and receives an impact, the front wheels (casters 204) of the transport cart 200 are in contact with the step 300 with a load applied, so the robot can maintain stable operation.

[Third embodiment]
This embodiment shows another aspect of the transfer robot 100. In the following description, differences from the first embodiment will be mainly described.

Figures 7 (A) to (C) show a second configuration of the transport robot 100. Figure 7 (A) shows a plan view of the transport robot 100, (B) shows a side view, and (C) shows a front view. The following will mainly explain the differences from the transport robot shown in Figures 2 (A) to (C).

The transport robot 100 has a table 134 provided on the top of the vehicle body 102. The table 134 is connected to the lift device 106 and moves up and down. The table 134 is supported by, for example, four lifters 128 (first lifter 128a, second lifter 128b, third lifter 128c, and fourth lifter 128d), and a spherical seat 136 is provided at the connecting portion. There is no limitation on the shape of the table 134. The upper surface of the table 134 comes into contact with the lower surface of the loading platform 202.

The lifters 128 (first lifter 128a, second lifter 128b, third lifter 128c, fourth lifter 128d) are mounted on a spherical seat 138. Each lifter is connected to the table 134 via a slider 136. By mounting each lifter 128 on the vehicle body 102 via the spherical seat 138, the angle of each lifter can be adjusted. By connecting each lifter 128 to the table 134 via the slider 136, the position at which the table 134 is supported can be adjusted. With this configuration, even if the vehicle body 102 tilts, the table 134 can be kept horizontal and the loading platform can be supported in a stable state.

Figure 8 (A) shows the stage where the transport robot 100 transporting the transport cart 200 climbs up onto the step 300. The transport robot 100 lifts the platform 202 while keeping the table 134 horizontal. The table 134 and the lifters 128 (first lifter 128a, second lifter 128b, third lifter 128c, fourth lifter 128d) are connected by sliders 136, and the angle of each lifter 128 can be changed by a spherical seat 138. Therefore, even if the vehicle body 102 is tilted at an angle, the horizontal state can be controlled while maintaining the upper surface of the table 134 horizontal (in other words, while almost the entire upper surface of the table 134 is in contact with the lower surface of the platform 202). Furthermore, each lifter 128 (first lifter 128a, second lifter 128b, third lifter 128c, fourth lifter 128d) can receive a load while standing vertically, so the transport cart 200 can be supported in a stable state.

Figure 8 (B) shows a state in which one side of the crawler unit 118 of the transport robot 100 has climbed up on a step. Specifically, when viewed from the front, the first crawler 126a on the left side of the transport robot 100 has climbed up on a step 300, causing the vehicle body 102 to tilt. Even in this state, the lift device 106 is controlled to raise the shafts of the first lifter 128a and third lifter 128c and, if necessary, lower the shafts of the second lifter 128b and fourth lifter 128d so that the table 134 remains horizontal. This operation of the transport robot 100 allows the loading platform 202 to be kept horizontal even if the vehicle body 102 tilts left or right relative to the direction of travel. Even in this state, the lifters 128 (first lifter 128a, second lifter 128b, third lifter 128c, fourth lifter 128d) can be made vertical by the ball seat 138, and the position supporting the table 134 can be adjusted by the slider 136, so the transport cart 200 can be supported in a stable state.

According to this embodiment, the lift device 106 is provided with a table 134, and the platform 202 is supported by the table 134, so that the transport vehicle 200 can be transported stably. Note that the transport robot 100 according to this embodiment can also perform control to apply a load to the front wheels of the transport vehicle 200 when climbing over a step 300, as shown in the second embodiment.

100: Transport robot, 102: Vehicle body, 104: Travel device, 106: Lift device, 108: Step detection sensor, 110: Drive mechanism, 112: Controller, 114: Tilt sensor, 116: Communication device, 117: Lifter drive unit, 118: Crawler unit, 120: Track, 122: Drive wheel, 124: Idler wheel, 126: Roller, 128: Lifter, 130: Shaft, 132: Support, 134: Table, 136: Slider, 138: Ball seat, 200: Transport cart, 202: Loading platform, 204: Caster, 206: Luggage, 300: Step

Claims (7)

A transport robot that transports a platform with casters attached thereto with the casters in a state where the casters are in contact with the ground ,
A vehicle body that fits under the bed;
a lift device provided on the vehicle body and capable of supporting and lifting the loading platform from below ;
A traveling device that causes the vehicle body to travel;
An inclination sensor that detects the inclination of the vehicle body;
a step detection sensor for detecting a step in a moving direction of the vehicle body;
Including,
The lift device is a transport robot characterized in that when the step detection sensor detects a step, the lift device lifts the loading platform so that the casters match the height of the step before the vehicle body gets over the step, and supports the loading platform horizontally when the vehicle body gets over the step. The lift device includes a plurality of lifters,
2. The transport robot according to claim 1 , wherein when the tilt sensor detects a tilt of the vehicle body, the plurality of lifters are individually controlled to support the platform horizontally. The transport robot according to claim 2 , wherein each of the plurality of lifters is provided with a support at a tip thereof that abuts against the platform. 3. The transport robot according to claim 2 , further comprising a receiving platform that contacts said loading platform, said receiving platform being supported by said plurality of lifters, said receiving platform and said plurality of lifters being connected via spherical seats. 5. The transport robot according to claim 1 , wherein the lift device tilts and lifts the platform so that a rear part of the platform is higher than a front part of the platform when the vehicle body runs over a step. The transport robot according to claim 5 , wherein the angle of inclination is equal to or greater than 1 degree and equal to or less than 3 degrees. The transport robot according to claim 1 , wherein the travel device is a crawler.

Images