Unmanned vehicles

Abstract

To make a vehicle less likely to fall down when an obstacle collides with an upper part of an unmanned traveling vehicle during its traveling.SOLUTION: In an unmanned traveling vehicle, a drive wheel 11 is provided on an underside of a vehicle body 3. A rear follower wheel 13b is provided on the underside of the vehicle body 3 and is located on a rear side of the drive wheel 11 in a traveling direction. A drive-wheel support member 23 supports the drive wheel 11 and is supported so as to be movable up and down relative to a vehicle body 3. A spring 25 applies an urging force to the drive-wheel support member 23 toward a floor F. A lower end 41b of a guide groove 41 restricts a lower side of a movable range of the drive-wheel support member 23. In the unmanned traveling vehicle, when a vehicle body 3 is inclined rearward in a traveling direction with the rear follower wheel 13b as a fulcrum, the lower end 41b of the guide groove 41 restricts downward movement of the drive-wheel support member 23, thereby reducing an urging force.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an unmanned vehicle. [Background technology]

[0002] One type of unmanned vehicle known is a shelf check robot that monitors product display shelves in stores such as convenience stores and supermarkets (see, for example, Patent Document 1). The shelf check robot monitors the product display shelves to check for any abnormalities in the product display state, and if an abnormality is found, a worker corrects the abnormality and performs product rearrangement or replenishment work. The shelf check robot has a vehicle body and multiple cameras. The multiple cameras are attached at predetermined intervals along the height of the vehicle body and capture images of the shelves in the retail store. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-98617 Summary of the Invention [Problem to be solved by the invention]

[0004] The shelf check robot has, for example, a drive wheel and driven wheels provided in front and behind the drive wheel. The shelf check robot has a tall body so that it can handle product display shelves with multiple tiers. Therefore, if an obstacle hits the upper part of the body while it is moving, there is a risk that the shelf check robot will tip over. Specifically, if the drive wheel continues to rotate and move forward even though an obstacle hits the upper part of the body while it is moving, the upper part of the body will remain in place while the lower part of the body will continue to move forward, significantly disrupting the balance of the body and raising a risk of tipping over.

[0005] An object of the present invention is to make it less likely for an unmanned vehicle to tip over when an obstacle hits the top of the unmanned vehicle while the unmanned vehicle is traveling. [Means for solving the problem]

[0006] Below, several aspects will be described as means for solving the problems. These aspects can be arbitrarily combined as necessary.

[0007] An unmanned vehicle according to one aspect of the present invention travels on a floor surface and includes a vehicle body, drive wheels, driven wheels, a drive wheel support member, a biasing member, and a stopper. The drive wheels are provided on the lower part of the vehicle body, and the driven wheels are provided on the lower part of the vehicle body, and are located rearward of the drive wheels in the direction of travel. The drive wheel support member supports the drive wheels and is supported so as to be vertically movable relative to the vehicle body. The biasing member applies a biasing force to the drive wheel support member toward the floor surface. The stopper limits the lower side of the movable range of the drive wheel support member.

[0008] In this unmanned vehicle, if an obstacle hits the top of the vehicle body while it is traveling, the vehicle body will tilt rearward in the direction of travel, with the driven wheels as the fulcrum. At this time, the stopper restricts the downward movement of the drive wheel support member. By restricting the downward movement of the drive wheel support member by the stopper, the biasing force applied to the drive wheel support member by the biasing member is reduced. In other words, the force with which the biasing member presses the drive wheel against the floor surface is weakened. As a result, even if the drive wheel continues to rotate, the drive force of the drive wheel is no longer transmitted to the floor surface, and the unmanned vehicle stops moving forward. By providing a stopper that functions just before the vehicle body exceeds the limit at which it would tip over, the vehicle body will not tilt any further, and as a result, the unmanned vehicle will not tip over.

[0009] The drive wheel support member may be tiltably mounted around a hinge axis at the bottom of the vehicle body. The unmanned vehicle may further include an engagement portion and a guide member. The engagement portion is provided on the drive wheel support member. The guide member is provided on the vehicle body and has a guide portion that guides the engagement portion so that it can move freely in both directions. In this unmanned vehicle, the up and down movement of the drive wheel support member is stable.

[0010] The biasing member may be a tension spring that is stretched between the drive wheel support member and the vehicle body and applies a load to the drive wheel support member in the tilting direction. The guide member may extend in the vertical direction. The guide portion may guide the engagement portion in the vertical direction. The stopper may be the lower end of the guide portion that limits the lower side of the movable range of the engagement portion. This unmanned vehicle has a small overall height.

[0011] The biasing member may be a compression spring member that is stretched between the drive wheel support member and the vehicle body and applies a load to the drive wheel support member in the tilting direction. The guide member may extend in the traveling direction of the unmanned vehicle. The guide portion may guide the engagement portion in the traveling direction. The stopper may also serve as a guide portion for limiting the lower side of the movable range of the engagement portion and may be provided on the rear side in the traveling direction. In this unmanned vehicle, the projected area of ​​the vehicle body when viewed from above is small, making it easier to travel through narrow passages. Furthermore, by using a compression spring member as the biasing member, the durability of the biasing member can be improved.

[0012] The engaging portion is a protrusion, and there may be a plurality of engaging portions. In this unmanned vehicle, for example, two engaging portions are located at separate positions, so that the drive wheel support member is less likely to swing in a direction intersecting the direction of travel with respect to the guide member.

[0013] The biasing member may be a compression spring member that is stretched between the drive wheel support member and the vehicle body and applies a load in the tilting direction to the drive wheel support member. The stopper may be a plate-like member that is provided at one end of the biasing member and limits the expansion and contraction of the biasing member. In this unmanned vehicle, the stopper can serve as both the biasing member and the biasing member, and the movable range of the drive wheel support member can be set as desired.

[0014] The biasing member may be a torsion coil spring that is provided on the hinge shaft and applies a load in the tilting direction to the drive wheel support member. By providing the hinge shaft with a torsion coil spring as the biasing member, the unmanned vehicle can be made compact.

[0015] The biasing members may be disposed between the underside of the vehicle body and the upper surface of the drive wheel support member at two locations, one in front and one in back in the direction of travel of the unmanned autonomous vehicle. The stopper may include a plate member fixed to the vehicle body and extending horizontally, and a rod provided on the plate member at two locations, one in front and one in back in the direction of travel of the unmanned autonomous vehicle, and extending upward. The stopper limits the lower side of the range of motion of the drive wheel support member by the underside of the drive wheel support member abutting against the upper surface of the rod. This unmanned autonomous vehicle can overcome relatively small undulations and irregularities on the floor surface. Furthermore, even if the vehicle body tilts rearward in the direction of travel with the driven wheels as fulcrums, the balance of the vehicle body is not significantly disrupted, and the unmanned autonomous vehicle will not tip over.

[0016] The vehicle body may have a height dimension that is three or more times larger than the length in the traveling direction. This unmanned vehicle has a tall vehicle body, and therefore the above-described tip-over prevention measures are effective.

[0017] The unmanned vehicle may be a shelf-checking robot that travels on the floor of a retail store. The unmanned vehicle may further include a plurality of cameras that are attached at predetermined intervals along the height of the vehicle body and capture images of the shelves in the retail store. This unmanned vehicle has a tall body structure, and therefore the above-described tip-over prevention measures are effective. [Effects of the Invention]

[0018] The unmanned vehicle according to the present invention is less likely to tip over when an obstacle hits the top of the unmanned vehicle while it is traveling. [Brief explanation of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a shelf check robot. [Figure 2] FIG. 1 is a perspective view of a shelf check robot. [Figure 3] FIG. 1 is a schematic side view of a shelf check robot. [Figure 4] FIG. 1 is a schematic side view of a shelf check robot. [Figure 5] FIG. [Figure 6] FIG. [Figure 7] FIG. 4 is a schematic diagram for explaining the maximum stroke length of a drive wheel. [Figure 8] FIG. 10 is a perspective view of a drive wheel support structure according to a second embodiment. [Figure 9] FIG. 10 is a side view of the drive wheel support structure of the second embodiment. [Figure 10] FIG. 10 is a perspective view of a drive wheel support structure according to a third embodiment. [Figure 11] FIG. 2 is a longitudinal cross-sectional view of a compression spring member. DETAILED DESCRIPTION OF THE INVENTION

[0020] 1. First embodiment (1) Basic structure of shelf check robot A shelf check robot 1 (an example of an unmanned vehicle) will be described using Figures 1 to 3. Figures 1 and 2 are perspective views of the shelf check robot. Figure 3 is a schematic side view of the shelf check robot. In the figures, the outline arrows indicate the traveling direction of the shelf check robot 1. The shelf check robot 1 travels on floor surface F to monitor product display shelves in retail stores such as convenience stores and supermarkets. The shelf check robot 1 has a vehicle body 3. The vehicle body 3 is relatively tall, and specifically, its height is at least three times its traveling length.

[0021] The shelf check robot 1 has an obstacle detection camera 5. The obstacle detection camera 5 is installed on the front side in the direction of travel and faces diagonally downward. The obstacle detection camera 5 is, for example, a TOF (Time of Flight) camera. The shelf check robot 1 has multiple cameras 7. The multiple cameras 7 are attached at predetermined intervals in the height direction of the vehicle body 3 and photograph the shelves of a large retail store. Specifically, the multiple cameras 7 are installed on one side of the vehicle body 3 and face horizontally. The captured images are processed by a controller (not shown). As a result, the controller can check the expiration date, selling price, out-of-stock status, etc. of POP (Point of Purchase) advertisements. The shelf check robot 1 has bumper switches 9 at the front and rear of the lowest part of the vehicle body 3 in the direction of travel.

[0022] The shelf check robot 1 has drive wheels 11 (an example of a drive wheel). The drive wheels 11 are provided on the lower part of the vehicle body 3. Specifically, the drive wheels 11 are a pair on the left and right, and are provided in the center of the lower part of the vehicle body 3 in the traveling direction. The drive wheels 11 are driven by a motor and a reduction mechanism (not shown). As an example, the motor and the reduction mechanism are directly connected to the drive wheels 11.

[0023] The shelf check robot 1 has front driven wheels 13a and rear driven wheels 13b. The front driven wheels 13a and rear driven wheels 13b are provided on the lower part of the vehicle body 3. The front driven wheels 13a are provided forward of the drive wheels 11 in the direction of travel and form a pair on the left and right. The rear driven wheels 13b (an example of a driven wheel) are provided rear of the drive wheels 11 in the direction of travel and form a pair on the left and right. The shelf check robot 1 has a drive wheel support structure 21 (described below).

[0024] (2) Drive wheel support structure (2-1) Basic configuration of drive wheel support structure The structure of the drive wheel support structure 21 will be explained using Figures 3 to 6. Figure 4 is a schematic side view of the shelf check robot. Figures 5 and 6 are perspective views of the drive wheel support structure. The drive wheel support structure 21 is a structure that supports the drive wheel 11 movably within a predetermined vertical range by a suspension. The drive wheel support structure 21 has a drive wheel support member 23, a spring 25, and a guide mechanism 27.

[0025] The drive wheel support member 23 (an example of a drive wheel support member) supports the drive wheel 11. The drive wheel support member 23 is a plate-shaped member such as a bracket. The drive wheel support member 23 is provided so as to be tiltable up and down around a hinge shaft 29 at the front lower part of the vehicle body 3. The axis of the hinge shaft 29 extends in the left-right direction.

[0026] The spring 25 (an example of a biasing member) is hung between the upper end of the drive wheel support member 23 on the front side in the traveling direction and the lower end 33a of the bracket 33 of the vehicle body 3, and biases the drive wheel 11 against the floor surface F by rotating the drive wheel support member 23 around the hinge shaft 29. Specifically, the spring 25 is a tension coil spring.

[0027] (2-2) Guide mechanism The guide mechanism 27 is a mechanism that guides the tilting of the drive wheel support member 23. The guide mechanism 27 has a base 35, an engagement protrusion 37, and a guide member 39. The base 35 is provided on the rear portion of the drive wheel support member 23 in the traveling direction. The engagement protrusion 37 (an example of an engagement portion) is provided on the base 35 and protrudes rearward in the traveling direction. The engagement protrusion 37 is a cylindrical pin. The engagement protrusion 37 is inserted into a guide groove 41 (described later) and functions as a guide shaft. Specifically, two engagement protrusions 37 are provided, one above the other, and the two engagement protrusions 37 are spaced apart from each other vertically.

[0028] The guide member 39 (an example of a guide member) extends in the vertical direction, and is fixed to the vehicle body 3 rearward in the traveling direction of the drive wheel support member 23. The guide member 39 has a guide groove 41 (an example of a guide portion) that extends vertically. The guide groove 41 accommodates the engagement protrusion 37 so that it can move vertically. Specifically, the guide groove 41 is provided along the trajectory of the rotation of the engagement protrusion 37 around the hinge shaft 29.

[0029] The guide groove 41 has an upper end 41a and a lower end 41b (an example of a stopper, a lower end) that function as stoppers that limit the range of motion of the engagement protrusion 37. When the upper engagement protrusion 37 abuts against the upper end 41a of the guide groove 41, the drive wheel 11 does not move any further upward relative to the vehicle body 3. This prevents, for example, a motor (not shown) fixed to the drive wheel support member 23 from colliding with other members. When the lower engagement protrusion 37 abuts against the lower end 41b of the guide groove 41, it does not move any further downward relative to the vehicle body 3. In this way, by using the lower end 41b of the guide groove 41 as a stopper, the guide groove 41 can be used both as a guide and a stopper for the engagement protrusion 37.

[0030] The up and down movement of the drive wheel support member 23 is guided by the above-mentioned guide mechanism 27, which restricts movement of the drive wheel support member 23 in a direction intersecting the traveling direction, thereby stabilizing the up and down movement of the drive wheel support member 23.

[0031] Due to the drive wheel support structure 21, during normal driving, the drive wheels 11 are pressed against the floor surface F, and the engagement protrusions 37 are positioned in the vertical center of the guide grooves 41 as shown in Figure 5. This positions the lower part of the vehicle body 3 at a distance above the floor surface F. This allows the shelf check robot 1 to overcome relatively small undulations and irregularities on the floor surface F, such as steps in thresholds or floor mats.

[0032] In the drive wheel support structure 21 having the above configuration, the spring 25 is suspended between the upper end portion of the drive wheel support member 23 on the front side in the traveling direction and the lower end 33a of the bracket 33. In addition, the guide member 39 is provided on the rear side in the traveling direction of the drive wheel support member 23. This reduces the vertical dimension of the drive wheel support structure 21, allowing the overall height of the shelf check robot 1 to be reduced.

[0033] In this embodiment, the two engaging protrusions 37 are positioned vertically apart (the guided portions are positioned vertically apart), so the drive wheel support member 23 is less likely to swing in the direction intersecting the traveling direction relative to the guide member 39. In this embodiment, the shelf checking robot 1 has a tall body 3, and therefore the above-described tipping prevention measures are effective.

[0034] (3) Operation of the drive wheel support mechanism during normal driving and when hitting an obstacle The operation of the drive wheel support structure 21 when the shelf-checking robot 1 is traveling normally and when it hits an obstacle will be described using Figures 3 to 6. Figure 4 is a schematic side view of the shelf-checking robot. Figures 5 and 6 are perspective views of the drive wheel support structure.

[0035] (3-1) Operation of the drive wheel support mechanism during normal driving 3 and 5, during normal travel of the shelf check robot 1, the engagement protrusion 37 of the drive wheel support member 23 is located at the vertical middle position of the guide groove 41 of the guide member 39. Therefore, the drive wheel 11 is movable up and down.

[0036] (3-2) Operation of the drive wheel support mechanism when hitting an obstacle As shown in Figure 4, when an obstacle 51 hits the upper part of the body 3 while the shelf-checking robot 1 is traveling, the body 3 of the shelf-checking robot 1 tilts rearward in the traveling direction, with the rear driven wheel 13b as the fulcrum. In the initial stage of this collision, the tilt angle of the body 3 is small, so the biasing force of the spring 25 is large. Therefore, the drive wheel 11 is pressed against the floor surface F with a relatively large force, and as the drive wheel 11 continues to rotate, the body 3 continues to move forward, causing the body 3 to tilt further.

[0037] When the vehicle body 3 tilts to a predetermined angle, as shown in Figure 6, the biasing force of the spring 25 moves the lower engagement protrusion 37 to the lower end 41b of the guide groove 41, and the drive wheel 11 stops moving downward any further. When the vehicle body 3 tilts to a predetermined angle and the drive wheel 11 stops moving downward, the force of the spring 25 pressing the drive wheel 11 against the floor surface F weakens. Therefore, even if the drive wheel 11 continues to rotate, the drive force of the drive wheel 11 is no longer transmitted to the floor surface F, and the shelf check robot 1 stops moving forward. Before the vehicle body 3 exceeds the limit at which it would tip over, the lower end 41b of the guide groove 41 functions as a stopper, preventing the vehicle body 3 from tilting beyond the predetermined angle (the state of Figure 4 is maintained), and the shelf check robot 1 does not tip over.

[0038] (3-3) Maximum downward stroke length of the drive wheel Hereinafter, the maximum downward stroke length of the drive wheels 11 to prevent the vehicle body 3 from tilting beyond a predetermined angle will be described with reference to Fig. 7. Fig. 7 is a schematic diagram for explaining the maximum stroke length of the drive wheels. As shown in Fig. 7, if the maximum tilt angle (i.e., the above-mentioned predetermined angle) to prevent the vehicle body 3 from tipping over is θ and the distance between the center of the drive wheels 11 and the center of the rear driven wheels 13b is L, the maximum vertical stroke length S of the drive wheels 11 is L*tan θ.

[0039] That is, the drive wheel support structure 21 (guide groove 41) is designed so that the downward stroke of the drive wheel 11 is equal to or less than the maximum stroke length S (L*tan θ). More specifically, it is designed so that the lower engagement protrusion 37 comes into contact with the lower end 41b of the guide groove 41 when the drive wheel 11 is lowered by the maximum stroke length S.

[0040] 2. Second embodiment In the first embodiment, the drive wheel support member is supported so as to be tiltable around a hinge axis at the bottom of the vehicle body, but the drive wheel support member only needs to be supported so as to be movable up and down relative to the vehicle body, and may be supported so as to be movable up and down, for example, directly downward relative to the vehicle body. Such an example will be described as a second embodiment using Figures 8 and 9. Figure 8 is a perspective view of the drive wheel support structure of the second embodiment. Figure 9 is a side view of the drive wheel support structure of the second embodiment.

[0041] The drive wheel support structure 21A is a structure that supports the drive wheel 11A movably within a predetermined vertical range by a suspension, and includes a drive wheel support member 23A, a spring 25A, and a stopper 27A.

[0042] The drive wheel support member 23A (an example of a drive wheel support member) supports the drive wheel 11A. The drive wheel support member 23A is a plate-shaped member such as a bracket. The drive wheel support member 23A is provided so as to be movable up and down relative to the vehicle body 3A.

[0043] Spring 25A (an example of a biasing member) is disposed between the lower surface of vehicle body 3A and the upper surface of drive wheel support member 23A, and biases drive wheel support member 23A against floor surface F. Specifically, spring 25A is a compression coil spring. Spring 25A is provided at two locations, one at the front and one at the back of each drive wheel support member 23A in the traveling direction.

[0044] The stopper 27A is a plate member disposed below the drive wheel support member 23A. The stopper 27A has a plate member 27A1 fixed to the vehicle body 3A and extending horizontally, and a rod 27A2 attached to the plate member 27A1 and extending upward. Specifically, the rods 27A2 are provided at two locations, one at the front and one at the rear in the traveling direction, for each drive wheel support member 23A. When the lower surface of the drive wheel support member 23A abuts against the upper surface of the rod 27A2, the drive wheel support member 23A does not move further downward relative to the vehicle body 3A.

[0045] Due to the drive wheel support structure 21A described above, during normal travel, the drive wheel 11A is pressed against the floor surface F, and the lower surface of the drive wheel support member 23A is located away from the upper surface of the rod 27A2 of the stopper 27A. This positions the lower part of the vehicle body 3A at a position spaced upward from the floor surface F. Therefore, the shelf check robot 1A can overcome relatively small undulations and irregularities on the floor surface F, such as steps in thresholds or floor mats.

[0046] As in the first embodiment, when an obstacle hits the upper part of the body 3A while the shelf-checking robot 1A is traveling, the body 3A of the shelf-checking robot 1A tilts rearward in the traveling direction, with the rear driven wheel 13Ab as the fulcrum. In the initial stage of the collision, the tilt angle of the body 3 is small, so the biasing force of the spring 25A is large. Therefore, the drive wheel 11A is pressed against the floor surface F with a relatively large force, and as the drive wheel 11A continues to rotate, the body 3A continues to move forward, causing the body 3A to tilt further.

[0047] When the vehicle body 3 tilts to a predetermined angle, the biasing force of the spring 25A moves the drive wheel support member 23A downward, and the lower surface of the drive wheel support member 23A abuts against the upper surface of the rod 27A2 of the stopper 27A, preventing the drive wheel 11A from moving downward any further. When the vehicle body 3A tilts to a predetermined angle and the drive wheel 11A stops moving downward, the force of the spring 25A pressing the drive wheel 11A against the floor surface F weakens. Therefore, even if the drive wheel 11A continues to rotate, the drive force of the drive wheel 11A is no longer transmitted to the floor surface F, and the shelf check robot 1A stops moving forward. By providing the stopper 27A, which functions just before the vehicle body 3 exceeds the limit at which it would tip over, the vehicle body 3A will not tilt beyond the predetermined angle, preventing the shelf check robot 1A from tipping over.

[0048] 3. Third embodiment In the first embodiment, the biasing member is a tension coil spring stretched between the upper end of the drive wheel support member on the front side in the traveling direction and the lower end 33a of the bracket 33 of the vehicle body 3. However, as long as the biasing member biases the drive wheel support member toward the floor, a spring other than a tension coil spring can be used. For example, a compression spring member can also be used as the biasing member. Furthermore, as long as the guide mechanism can guide the drive wheel support member movably in both directions, the configuration of the guide mechanism is not limited to the configuration described in the first embodiment. For example, the guide member can be a member extending in the traveling direction. Such an example will be described as a third embodiment using FIG. 10. FIG. 10 is a perspective view of the drive wheel support structure of the third embodiment.

[0049] The drive wheel support structure 21B has a drive wheel support member 23B, a compression spring member 25B, and a guide mechanism 27B. The drive wheel support member 23B (an example of a drive wheel support member) supports the drive wheel 11B. The drive wheel support member 23B is a plate-shaped member such as a bracket. The drive wheel support member 23B is provided so as to be tiltable up and down around a hinge shaft 29B at the front lower part of the vehicle body 3. The axis of the hinge shaft 29B extends in the left-right direction.

[0050] The compression spring member 25B (an example of a biasing member) is suspended between the first mounting portion 23B1 provided on the rear side of the drive wheel support member 23B in the traveling direction and the vehicle body 3, and biases the drive wheel 11B against the floor surface F by rotating the drive wheel support member 23B around the hinge axis 29B.

[0051] The compression spring member 25B will be specifically described below with reference to Figures 10 and 11. Figure 11 is a longitudinal cross-sectional view of the compression spring member. The compression spring member 25B has a compression spring 251, a cylinder member 252, a shaft 253, a first plate-shaped member 254, and a second plate-shaped member 255.

[0052] The compression spring 251 generates a biasing force of the compression spring member 25B. The compression spring 251 is, for example, a compression coil spring. The cylinder member 252 houses the compression spring 251 inside. A second mounting portion 252a is provided at one longitudinal end of the outer circumferential surface of the cylinder member 252. The second mounting portion 252a is rotatably mounted to the vehicle body 3 by a mounting shaft 31B. In other words, one end of the compression spring member 25B closer to the vehicle body 3 is rotatably mounted to the vehicle body 3 via the second mounting portion 252a and the mounting shaft 31B.

[0053] The shaft 253 transmits the biasing force of the compression spring 251 to the drive wheel support member 23B. A spring compression portion 253a is provided midway along the length of the shaft 253. The spring compression portion 253a is inserted into the cylinder member 252 and abuts against one end of the compression spring 251. The other end of the compression spring 251 abuts against the inner wall of the cylinder member 252 at its terminal end. A third mounting portion 253b is provided at one end of the shaft 253. The third mounting portion 253b is rotatably attached to the first mounting portion 23B1 by a mounting shaft 23B2. That is, the end of the compression spring member 25B farther from the vehicle body 3 is rotatably attached to the rear side of the drive wheel support member 23B in the traveling direction via the first mounting portion 23B1 and the mounting shaft 23B2.

[0054] In the compression spring member 25B having the above configuration, the compression spring 251 expands and contracts between the spring compression portion 253a and the end of the cylinder member 252, thereby changing the amount of protrusion of the shaft 253 from the cylinder member 252. At this time, a pressing force corresponding to the length of the compression spring 251 (i.e., the amount of protrusion of the shaft 253 from the cylinder member 252) is generated in the third attachment portion 253b provided at the end of the shaft 253. This pressing force is transmitted to the drive wheel support member 23B via the third attachment portion 253b.

[0055] The first plate-shaped member 254 is provided on the third mounting portion 253b side in the longitudinal direction of the shaft 253. The first plate-shaped member 254 abuts against the outer wall on the base end side of the cylinder member 252, thereby restricting the expansion and contraction of the compression spring 251 inside the cylinder member 252 and restricting the insertion of the shaft 253 into the cylinder member 252. In other words, the first plate-shaped member 254 functions as a stopper that restricts the upward movement of the drive wheel support member 23B.

[0056] The first plate-shaped member 254 is movable in the longitudinal direction of the shaft 253. This allows the allowable insertion amount of the shaft 253 into the cylinder member 252 to be adjusted, thereby adjusting the upward movable range of the drive wheel support member 23B.

[0057] The second plate-shaped member 255 is provided on the opposite side of the shaft 253 from the third mounting portion 253b in the longitudinal direction. The second plate-shaped member 255 abuts against the outer wall on the terminal end side of the cylinder member 252, thereby restricting the expansion and contraction of the compression spring 251 inside the cylinder member 252 and restricting the protrusion of the shaft 253 from the cylinder member 252. In other words, the second plate-shaped member 255 functions as a stopper that restricts the downward movement of the drive wheel support member 23B. This allows the compression spring member 25B to serve both as a stopper that restricts the movement of the drive wheel support member 23B and as a biasing member that biases the drive wheel support member 23B.

[0058] The second plate-shaped member 255 is movable in the longitudinal direction of the shaft 253. This allows the allowable amount of protrusion of the shaft 253 into the cylinder member 252 to be adjusted, thereby adjusting the downward movable range of the drive wheel support member 23B.

[0059] Returning to FIG. 10, guide mechanism 27B is a mechanism that guides the tilting of drive wheel support member 23B. Guide mechanism 27B has an engagement protrusion 37B and a guide member 39B. Engagement protrusion 37B (an example of an engagement portion) protrudes upward from drive wheel support member 23B. Engagement protrusion 37B is a cylindrical pin. Engagement protrusion 37B is inserted into guide groove 41B and functions as a guide shaft. Specifically, two engagement protrusions 37B are provided along the traveling direction, and the two engagement protrusions 37B are spaced apart from each other in the traveling direction.

[0060] The guide member 39B (an example of a guide member) extends in the traveling direction and is fixed to the vehicle body 3 at a position above the drive wheel support member 23B. The guide member 39B has a guide groove 41B (an example of a guide portion) that extends in the traveling direction. The guide groove 41B accommodates the engaging protrusion 37B so that the engaging protrusion 37B is movable in the traveling direction. Specifically, the guide groove 41B is provided along the path of rotation of the engaging protrusion 37B around the hinge shaft 29B.

[0061] The guide groove 41B has a front end 41Ba and a rear end 41Bb (an example of a rear stopper) that function as a stopper that can limit the range of motion of the engagement protrusion 37B. When the engagement protrusion 37B on the front side in the traveling direction abuts against the front end 41Ba of the guide groove 41B, the drive wheel 11B does not move any further upward relative to the vehicle body 3. This prevents, for example, a motor (not shown) fixed to the drive wheel support member 23B from colliding with another member. When the engagement protrusion 37B on the rear side in the traveling direction abuts against the rear end 41Bb of the guide groove 41B, the drive wheel 11B does not move any further downward relative to the vehicle body 3. In this way, by using the rear end 41Bb of the guide groove 41B as a stopper, the guide groove 41B can be used both as a guide and a stopper for the engagement protrusion 37B.

[0062] The up and down movement of the drive wheel 11B may be limited by only or both of the first plate-shaped member 254 and the second plate-shaped member 255 of the compression spring member 25B or the front end 41Ba and the rear end 41Bb of the guide groove 41B. In other words, only or both of the first plate-shaped member 254 and the second plate-shaped member 255 of the compression spring member 25B or the front end 41Ba and the rear end 41Bb of the guide groove 41B may be used as a stopper.

[0063] In this embodiment, when an obstacle 51 hits the upper part of the body 3 while the shelf-checking robot 1 is traveling, the body 3 of the shelf-checking robot 1 tilts rearward in the traveling direction, with the rear driven wheel 13b as the fulcrum. In the initial stage of this collision, the tilt angle of the body 3 is small, so the biasing force of the compression spring member 25B is large. Therefore, the drive wheel 11B is pressed against the floor surface F with a relatively large force, and as the drive wheel 11B continues to rotate, the body 3 continues to move forward, causing the body 3 to tilt further.

[0064] When the vehicle body 3 tilts to a predetermined angle, the drive wheel 11B does not move downward any further. When the vehicle body 3 tilts to a predetermined angle and the drive wheel 11B stops moving downward, the force with which the compression spring member 25B presses the drive wheel 11B against the floor surface F weakens. Therefore, even if the drive wheel 11B continues to rotate, the drive force of the drive wheel 11B is no longer transmitted to the floor surface F, so the shelf check robot 1 stops moving forward and the vehicle body 3 does not tilt beyond the above-mentioned predetermined angle. As a result, the balance of the vehicle body 3 is not significantly lost and the shelf check robot 1 does not tip over.

[0065] The up and down movement of the drive wheel support member 23B is guided by the above-mentioned guide mechanism 27B, so that the movement of the drive wheel support member 23B in a direction intersecting the traveling direction is restricted, and the up and down movement of the drive wheel support member 23B is stabilized.

[0066] Due to the drive wheel support structure 21B described above, during normal driving, the drive wheel 11B is pressed against the floor surface F, and the engagement protrusion 37B is positioned midway within the guide groove 41B. This positions the lower part of the vehicle body 3 at a distance above the floor surface F. Therefore, the shelf check robot 1 can overcome relatively small undulations and irregularities on the floor surface F, such as steps in thresholds or floor mats.

[0067] Furthermore, in the drive wheel support structure 21B having the above configuration, the compression spring member 25B is suspended between the first mounting portion 23B1 on the rear side of the drive wheel support member 23 in the traveling direction and the vehicle body 3. Furthermore, the guide member 39B extends in the traveling direction and is provided above the drive wheel support member 23B. This reduces the projected area of ​​the vehicle body 3 when viewed from above, making it easier for the shelf check robot 1 to travel through narrow aisles. Furthermore, by using a compression spring 251 for the compression spring member 25B (biasing member), the durability of the compression spring member 25B can be improved.

[0068] In this embodiment, the two engaging protrusions 37B are positioned apart from each other in the running direction (the guided parts are positioned apart in the running direction), so the drive wheel support member 23B is less likely to swing in the direction intersecting the running direction relative to the guide member 39B.

[0069] 4. Fourth embodiment In the first and third embodiments, the biasing member that biases the drive wheel support member is the spring 25 or compression spring member 25B that is suspended between the drive wheel support member and the vehicle body. However, this is not limited to this. If the drive wheel support member is tiltably mounted around a hinge shaft at the bottom of the vehicle body, the biasing member may be a torsion coil spring that is mounted on the hinge shaft and applies a load to the drive wheel support member in the tilting direction. By providing a biasing member that is a torsion coil spring on the hinge shaft, there is no need to provide the spring 25 or compression spring member 25B, which allows the drive wheel support structure to be made more compact. As a result, the shelf check robot 1 can be made more compact.

[0070] Even when a torsion coil spring is provided on the hinge shaft as a biasing member, the spring 25 of the first embodiment or the compression spring member 25B of the third embodiment may be provided separately. That is, the first embodiment and the fourth embodiment may be combined, or the third embodiment and the fourth embodiment may be combined.

[0071] 5. Other Embodiments Although several embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the gist of the invention. In particular, several embodiments and modifications described in this specification can be arbitrarily combined as necessary. The engaging projections may be provided in parallel in the left-right direction, and there may be one or three or more.

[0072] The shapes of the engagement protrusion and engagement groove are not particularly limited. For example, the upper end of the engagement groove may be omitted.

[0073] The present invention is effective for tall robots, but can also be applied to short robots. The present invention can also be applied to unmanned vehicles other than shelf-checking robots, such as signage robots, service robots, and disinfection robots. [Industrial Applicability]

[0074] The present invention is widely applicable to unmanned vehicles. [Explanation of symbols]

[0075] 1: Shelf check robot 3: Body 5: Obstacle detection camera 7: Camera 11: Drive wheel 13a: Front driven wheel 13b: Rear driven wheel 21: Drive wheel support structure 23: Drive wheel support member 25: Spring 27: Guide mechanism 29: Hinge axis 33: Bracket 33a: Bottom end 35: Base 37: Engagement protrusion 39: Guide member 41: Guide groove 41a: Upper end 41b: Bottom end 51: Obstacle

Claims

1. An unmanned vehicle that travels on a floor, The car body and a driving wheel and a driven wheel provided at a lower portion of the vehicle body and located rearward of the driving wheel in a traveling direction; a drive wheel support member that is tiltably provided around a hinge shaft at a lower portion of the vehicle body, supports the drive wheel, and is supported so as to be vertically movable relative to the vehicle body; a biasing member that applies a biasing force to the drive wheel support member toward the floor surface; a stopper that limits a lower side of the movable range of the drive wheel support member; a plurality of engagement portions, which are protrusions provided on the drive wheel support member; a guide member provided on the vehicle body and having a guide portion that guides the engaging portion movably in both directions; Equipped with When the vehicle body tilts rearward in the traveling direction with the driven wheel as a fulcrum, the stopper restricts downward movement of the drive wheel support member, thereby reducing the biasing force; The plurality of engagement portions are arranged spaced apart from one another in the traveling direction. Unmanned vehicle.

2. An unmanned vehicle that travels on a floor, The car body and a driving wheel and a driven wheel provided at a lower portion of the vehicle body and located rearward of the driving wheel in a traveling direction; a drive wheel support member that is tiltably provided around a hinge shaft at a lower portion of the vehicle body, supports the drive wheel, and is supported so as to be vertically movable relative to the vehicle body; a biasing member that applies a biasing force to the drive wheel support member toward the floor surface; a stopper that limits a lower side of the movable range of the drive wheel support member; an engaging portion provided on the drive wheel support member; a guide member provided on the vehicle body and having a guide portion that guides the engaging portion movably in both directions; Equipped with When the vehicle body tilts rearward in the traveling direction with the driven wheel as a fulcrum, the stopper restricts downward movement of the drive wheel support member, thereby reducing the biasing force; the biasing member is a tension spring that is stretched between the drive wheel support member and the vehicle body and applies a load to the drive wheel support member in a tilting direction, The guide member extends in the vertical direction, the guide portion guides the engagement portion in the up-down direction, The stopper is a lower end of the guide portion for limiting the lower side of the movable range of the engagement portion. Unmanned vehicle.

3. An unmanned vehicle that travels on a floor, The car body and a driving wheel and a driven wheel provided at a lower portion of the vehicle body and located rearward of the driving wheel in a traveling direction; a drive wheel support member that is tiltably provided around a hinge shaft at a lower portion of the vehicle body, supports the drive wheel, and is supported so as to be vertically movable relative to the vehicle body; a biasing member that applies a biasing force to the drive wheel support member toward the floor surface; a stopper that limits a lower side of the movable range of the drive wheel support member; an engaging portion provided on the drive wheel support member; a guide member provided on the vehicle body and having a guide portion that guides the engaging portion movably in both directions; Equipped with When the vehicle body tilts rearward in the traveling direction with the driven wheel as a fulcrum, the stopper restricts downward movement of the drive wheel support member, thereby reducing the biasing force; the biasing member is a compression spring member that is stretched between the drive wheel support member and the vehicle body and applies a load to the drive wheel support member in a tilting direction, The guide member extends in the traveling direction, the guide portion guides the engagement portion in the traveling direction, The stopper is located on the rear side of the guide portion in the traveling direction to limit the lower side of the movable range of the engagement portion. Unmanned vehicle.

4. the biasing member is a compression spring member that is stretched between the drive wheel support member and the vehicle body and applies a load to the drive wheel support member in a tilting direction, The unmanned vehicle according to claim 1 , wherein the stopper is a plate-like member provided at one end of the biasing member and restricts expansion and contraction of the biasing member.

5. An unmanned vehicle that travels on a floor, The car body and a driving wheel and a driven wheel provided at a lower portion of the vehicle body and located rearward of the driving wheel in a traveling direction; a drive wheel support member that is tiltably provided around a hinge shaft at a lower portion of the vehicle body, supports the drive wheel, and is supported so as to be vertically movable relative to the vehicle body; a biasing member that applies a biasing force to the drive wheel support member toward the floor surface; a stopper that limits a lower side of the movable range of the drive wheel support member; an engaging portion provided on the drive wheel support member; a guide member provided on the vehicle body and having a guide portion that guides the engaging portion movably in both directions; Equipped with When the vehicle body tilts rearward in the traveling direction with the driven wheel as a fulcrum, the stopper restricts downward movement of the drive wheel support member, thereby reducing the biasing force; the biasing member is a torsion coil spring that is provided on the hinge shaft and applies a load in a tilting direction to the drive wheel support member; Unmanned vehicle.

6. An unmanned vehicle that travels on a floor, The car body and a driving wheel and a driven wheel provided at a lower portion of the vehicle body and located rearward of the driving wheel in a traveling direction; a drive wheel support member that supports the drive wheel and is supported so as to be vertically movable relative to the vehicle body; a biasing member that applies a biasing force to the drive wheel support member toward the floor surface; a stopper that limits a lower side of the movable range of the drive wheel support member; Equipped with When the vehicle body tilts rearward in the traveling direction with the driven wheel as a fulcrum, the stopper restricts downward movement of the drive wheel support member, thereby reducing the biasing force; the biasing members are disposed between the lower surface of the vehicle body and the upper surface of the drive wheel support member at two positions, one at the front and one at the rear in the traveling direction, the stopper includes a plate member fixed to the vehicle body and extending in a horizontal direction, and rods provided at two positions on the plate member, one at the front and one at the rear in the traveling direction, and extending upward; the stopper limits the lower side of the movable range of the drive wheel support member by abutting the lower surface of the drive wheel support member with the upper surface of the rod. Unmanned vehicle.

7. 7. The unmanned vehicle according to claim 1, wherein the vehicle body has a height dimension that is at least three times the length in the traveling direction.

8. the unmanned vehicle is a shelf check robot that travels on the floor of a retail store, The unmanned vehicle according to claim 7 , further comprising a plurality of cameras attached at predetermined intervals in the height direction of the vehicle body, for photographing shelves of the retail store.

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