Traveling robot

Abstract

To stabilize the charging operation of a traveling robot while improving the running performance of the traveling robot.SOLUTION: The mobile robot includes a power receiving interface mounted on the vehicle body, electrically connectable to the battery, and configured to receive electrical energy from a power supply interface of an external charging device, and a suspension interposed between the first wheel and the vehicle body. The second wheel is a wheel closest to the power receiving interface in a horizontal direction. The second wheel is coupled to the vehicle body such that a relative displacement amount in a vertical direction between the second wheel and the vehicle body is smaller than a relative displacement amount in the vertical direction between the first wheel and the vehicle body when an upward load is input to each of the first wheel and the second wheel.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a multi-wheeled running robot. [Background technology]

[0002] Patent Document 1 discloses a robot movement mechanism. In the movement mechanism, multiple wheels are connected to a vehicle body via swing arms, and a suspension is interposed between each swing arm and the vehicle body. The suspension in the movement mechanism improves the robot's running performance. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-51385 Summary of the Invention [Problem to be solved by the invention]

[0004] When the robot operates on battery power, the robot may be provided with a charging port for charging the battery. When the robot is charged using a stationary external charging device, the robot may run toward the power supply connector of the external charging device and engage the power supply connector with the charging port to charge.

[0005] However, when the robot is loaded with cargo and the suspension compresses, or when the suspension expands or contracts immediately after the robot passes over a step, the vehicle's height above the ground changes. In this state, the height above the ground of the robot's charging port and the height above the ground of the external charging device's power supply connector may not match, and the power supply connector may not fit properly into the charging port.

[0006] Therefore, one aspect of the present disclosure aims to stabilize the charging operation of a running robot while improving the running performance of the running robot. [Means for solving the problem]

[0007] A traveling robot according to one aspect of the present disclosure includes a plurality of wheels including at least one first wheel and at least one second wheel, a body supported by the plurality of wheels, a battery, a power receiving interface mounted on the body, electrically connectable to the battery, and configured to receive electrical energy from a power supply interface of an external charging device, and at least one suspension interposed between the at least one first wheel and the body. The second wheel is one of the plurality of wheels that is closest to the power receiving interface in the horizontal direction. The second wheel is coupled to the body such that when a certain downward load is applied to the body, the vertical relative displacement between the second wheel and the body is smaller than the vertical relative displacement between the first wheel and the body. [Effects of the Invention]

[0008] According to one aspect of the present disclosure, the charging operation of a running robot can be stabilized while improving the running performance of the running robot. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a running robot according to an embodiment, seen from diagonally behind. [Figure 2] FIG. 2 is a perspective view of the wheel and its vicinity of the running robot of FIG. [Figure 3] FIG. 3 is a schematic plan view of the running robot of FIG. 1 including wheels and a power receiving interface. [Figure 4] FIG. 4 is a block diagram of the running robot of FIG. [Figure 5] FIG. 5 is a diagram illustrating the charging operation of the traveling robot of FIG. [Figure 6] FIG. 6 is a vertical cross-sectional view illustrating the angle of the loading surface of the platform of the traveling robot of FIG. [Figure 7]FIG. 7 is a diagram of the first modified example, which corresponds to FIG. [Figure 8] FIG. 8 is a diagram of the second modified example, which corresponds to FIG. [Figure 9] FIG. 9 is a diagram of a third modified example, corresponding to FIG. [Figure 10] FIG. 10 is a view of the fourth modified example, which corresponds to FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment will be described with reference to the drawings.

[0011] FIG. 1 is a perspective view of a traveling robot 1 according to an embodiment, seen from diagonally behind. As shown in FIG. 1, the traveling robot 1 includes a plurality of wheels 20 and a body 11 supported by the wheels 20. The traveling robot 1 is an autonomous traveling robot that autonomously travels on the ground while detecting its own position on a map, but it may also be a remote-controlled robot that travels on the ground under remote control. The traveling robot 1 includes a loading platform 12 with a loading surface 12a facing upward, but it does not have to include a loading platform 12. The traveling robot 1 is a transport robot that transports luggage placed on the loading platform 12 to a destination, but it may also be a security robot that monitors its surroundings while traveling.

[0012] When there are no obstacles around the running robot 1, the direction in which the running robot 1 travels towards a destination is the forward direction of the running robot 1, and the opposite direction is the rear direction of the running robot 1. When the running robot 1 moves both forward and backward, the time the running robot 1 spends moving forward between two points is longer than the time the running robot 1 spends moving backward. Therefore, when the running robot 1 moves straight in multiple directions, the direction in which the running robot 1 spends the longest time moving between two points is the forward direction of the running robot 1, and the opposite direction is the rear direction of the running robot 1. In other words, the main direction of travel of the running robot 1 is the forward direction of the running robot 1. The side of the running robot 1 on which a user interface such as the touch panel display 15 is located may be referred to as the front side of the running robot 1. The side of the running robot 1 on which many environmental sensors for recognizing the surrounding environment are located may also be referred to as the front side of the running robot 1.

[0013] In this embodiment, the opening SA of the loading space S of the loading platform 12 of the traveling robot 1, i.e., the luggage entrance / exit, is located on the front side of the traveling robot 1. In this embodiment, the touch panel display 15 is located on the front side of the traveling robot 1. This allows the worker to operate the touch panel display 15 of the traveling robot 1 and to place and remove luggage from the loading platform 12 from the same direction relative to the traveling robot 1.

[0014] The vehicle body 11 has a vehicle body panel 17 arranged to surround the loading platform 12, and a vehicle body frame 18. The vehicle body frame 18 is a lower frame arranged below the loading platform 12. The vehicle body frame 18 is supported by wheels 20. The vehicle body panel 17 is supported by the vehicle body frame 18. The main outer contour of the traveling robot 1 in a plan view is rectangular. Specifically, the outer contour of the traveling robot 1 in a plan view at the height where the vehicle body panel 17 is arranged is rectangular. The traveling robot 1 is equipped with a lower cover 13 that surrounds a group of multiple wheels 20 from the horizontal outside. The outer peripheral contour of the lower cover 13 in a plan view is rectangular. The outer contour of the traveling robot 1 in a plan view is not particularly limited and may be, for example, a round or triangular shape.

[0015] The traveling robot 1 is equipped with a power receiving interface 14 for charging, which is arranged so as to be exposed on the outside of the lower cover 13. In this embodiment, a recess R that is recessed toward the front is provided on the rear surface 13a of the lower cover 13. The power receiving interface 14 is arranged in the recess R of the lower cover 13. The power receiving interface 14 faces toward the rear of the traveling robot 1. The protruding end of the power receiving interface 14 is located inside the recess R of the lower cover 13, or is located on the same plane as a portion of the rear surface 13a of the lower cover 13 that is adjacent to the recess R.

[0016] The form of the power receiving interface 14 is not limited to the one described above. For example, the rear surface 13a of the lower cover 13 may not have the recess R. The traveling robot 1 may not have the lower cover 13. The power receiving interface 14 may be disposed in a location other than the lower cover 13. The power receiving interface 14 may be mounted in a portion other than the rear of the vehicle body 11. The power receiving interface 14 may face in a direction other than the rear of the traveling robot 1.

[0017] Fig. 2 is a perspective view of wheels 20 and their vicinity of the running robot 1 of Fig. 1. As shown in Fig. 2, the wheels 20 include at least one first wheel and at least one second wheel. Here, the at least one first wheel includes a pair of front wheels 21 aligned in the left-right direction of the running robot 1, and the at least one second wheel includes a pair of rear wheels 22 aligned in the left-right direction of the running robot 1 behind the front wheels 21. The four wheels 20 are arranged at positions that form the vertices of a rectangle or square in a plan view.

[0018] Although the number of wheels 20 of the traveling robot 1 is four, it does not have to be four. For example, the number of either the front wheels 21 or the rear wheels 22 may be less than the number of the other of the front wheels 21 or the rear wheels 22. The number of wheels 20 may be three, or five or more. When the number of wheels 20 is three, the three wheels may be arranged at positions that form the vertices of a triangle in a plan view. When the number of wheels 20 is five, one wheel may be arranged at the center of a group of four wheels that are arranged at positions that form the vertices of a rectangle or square in a plan view.

[0019] The running robot 1 is equipped with, for example, the same number of electric motors 24 as the number of wheels 20. Each wheel 20 is coupled to a respective electric motor 24 that can operate independently of the others. The electric motors 24 are adjacent to the corresponding wheels 20 so as to directly drive the corresponding wheels 20. The electric motors 24 are arranged closer to the center of the running robot 1 in the left-right direction than the corresponding wheels 20. The running robot 1 is able to change its running direction by, for example, using Mecanum wheels as the wheels 20.

[0020] The arrangement of the electric motor 24 is not particularly limited, and the electric motor 24 may be arranged inside the corresponding wheel 20, for example. One electric motor 24 may be configured to drive two or more wheels 20. The wheel type of the traveling robot 1 is not particularly limited, and omni-wheels or an active steering mechanism may be adopted instead of Mecanum wheels. When omni-wheels or an active steering mechanism are adopted, the front wheels may be made driven wheels and the electric motor that drives the front wheels may be omitted.

[0021] The body frame 18 is disposed above each wheel 20. The body frame 18 extends horizontally. The outer contour of the body frame 18 in plan view has a substantially rectangular shape. Note that the outer contour of the body frame 18 in plan view does not have to be rectangular, and may be, for example, round or triangular.

[0022] A battery 23 is mounted on the body frame 18. Note that the battery 23 is not limited to being mounted on a sprung member based on a suspension 25 (described later), i.e., the body frame 18, but may also be mounted on an unsprung member. The battery 23 is disposed below the body frame 18. The battery 23 is suspended from the body frame 18. This makes effective use of the space below the body frame 18, and prevents a reduction in the capacity of the cargo bed 12.

[0023] At least a portion of the battery 23 is disposed at a height that overlaps the height range of the front wheels 21 or the rear wheels 22. The battery 23 is disposed between the group of front wheels 21 and rear wheels 22 on the right side and the group of front wheels 21 and rear wheels 22 on the left side. The battery 23 is disposed in the center of the body frame 18 in the left-right direction in a plan view. The battery 23 may be disposed at a position higher than the front wheels 21 and rear wheels 22. The battery 23 may be disposed above the body frame 18.

[0024] A bracket B1 is fixed to the rear of the body frame 18. The bracket B1 protrudes downward from the body frame 18. A power receiving interface 14 that can be electrically connected to a battery 23 is fixed to the bracket B1.

[0025] Although the power receiving interface 14 protrudes rearward from the bracket B1, it does not have to protrude. The power receiving interface 14 may also be fixed to the vehicle frame 18 without using a bracket.

[0026] The power receiving interface 14 is disposed below the body frame 18. This allows for effective use of the space below the body frame 18 and prevents a reduction in the capacity of the cargo bed 12. Specifically, the power receiving interface 14 is suspended from the body frame 18 via a bracket B1. For example, at least a portion of the power receiving interface 14 is disposed at a height that overlaps the height range of the rear wheels 22. A power receiving contact 14b (described later) of the power receiving interface 14 is disposed at a height that overlaps the height range of the rear wheels 22.

[0027] It is preferable that the power receiving interface 14 be disposed below the body frame 18, but the location of the power receiving interface 14 is not limited to this. For example, the power receiving interface 14 may be disposed at a location higher than the rear wheels 22. The power receiving interface 14 may be disposed below the body frame 18 and higher than the rear wheels 22. The power receiving interface 14 may be disposed above the body frame 18.

[0028] The bracket B1 and the power receiving interface 14 are disposed behind the battery 23. The power receiving interface 14 is mounted on the rear of the body 11 while facing rearward of the traveling robot 1. The power receiving interface 14 overlaps with the battery 23 when viewed from behind the traveling robot 1.

[0029] The power receiving interface 14 is an interface that receives power from the outside in order to charge the battery 23. In this embodiment, the power receiving interface 14 is a connector. The power receiving interface 14 may be a male connector or a female connector. The power receiving interface 14 includes a connector housing 14a that opens toward the rear of the traveling robot 1, and a power receiving contact 14b that is housed in the connector housing 14a and electrically connected to the battery 23. Specifically, the power receiving contact 14b may be a metal terminal that is electrically connected to the battery 23. The power receiving contact 14b of the power receiving interface 14 is exposed toward the rear of the traveling robot 1.

[0030] The right front wheel 21 and its connecting structure are basically the same as the left front wheel 21 and its connecting structure, and the right rear wheel 22 and its connecting structure are basically the same as the left rear wheel 22 and its connecting structure, so the following explanation will focus on the right front wheel 21 and the right rear wheel 22 as representative examples.

[0031] The front wheels 21 are connected to the body frame 18 via suspensions 25. Specifically, the housings of the electric motors 24 coupled to the front wheels 21 are connected to the body frame 18 via the suspensions 25. This allows the front wheels 21 to smoothly overcome any unevenness in the ground in front of the traveling robot 1 while absorbing vibrations. The suspensions 25 include, for example, coil springs, but may also include other types of springs such as leaf springs or air springs. The suspensions 25 may also include dampers. The suspensions 25 may also be a combination of multiple types of springs. The suspensions 25 may also be a combination of springs and dampers.

[0032] The rear wheels 22 are connected to the body frame 18 via links 26. The links 26 are, for example, rods having attachment portions at both ends. Specifically, the housings of the electric motors 24 coupled to the rear wheels 22 are connected to the body frame 18 via the links 26. The rear wheels 22 are connected to the body frame 18 without any suspensions. That is, in the traveling robot 1, the number of suspensions 25 is less than the number of wheels 20.

[0033] The links 26 connect the rear wheels 22 to the body frame 18 so that when the same upward load is input to the front wheels 21 and the rear wheels 22 while the body frame 18 is fixed, the amount of relative vertical displacement between the rear wheels 22 and the body frame 18 is smaller than the amount of relative vertical displacement between the front wheels 21 and the body frame 18. In other words, when all the wheels 20 of the traveling robot 1 are in contact with flat ground, the links 26 connect the rear wheels 22 to the body frame 18 so that when a certain downward load is applied to a part of the body frame 18 that is located at the same position in the fore-and-aft direction as the center position between the front wheels 21 and the rear wheels 22, the amount of relative vertical displacement between the rear wheels 22 and the body frame 18 is smaller than the amount of relative vertical displacement between the front wheels 21 and the body frame 18.

[0034] In this embodiment, the link 26 inelastically connects the rear wheel 22 to the body frame 18. The link 26 rigidly connects the rear wheel 22 to the body frame 18. If the front wheel 21 corresponds to the first wheel and the rear wheel 22 corresponds to the second wheel, this configuration is an example of a configuration in which the second wheel is coupled to the body such that when the same upward load is input to the first wheel and the second wheel with the body frame 18 fixed, the amount of relative displacement in the vertical direction between the second wheel and the body is smaller than the amount of relative displacement in the vertical direction between the first wheel and the body.

[0035] Note that the link 26 may connect the rear wheel 22 to the body frame 18 via another member, for example, an elastic body such as rubber, as long as the amount of vertical relative displacement between the rear wheel 22 and the body frame 18 when the same upward load is applied to each of the front wheel 21 and the rear wheel 22 is smaller than the amount of vertical relative displacement between the front wheel 21 and the body frame 18. For example, the amount of vertical deformation of the elastic body is smaller than the amount of vertical displacement of the suspension 25.

[0036] A suspension may also be interposed between the rear wheel 22 and the body frame 18, as long as the amount of relative vertical displacement between the rear wheel 22 and the body frame 18 is smaller than the amount of relative vertical displacement between the front wheel 21 and the body frame 18 when the same upward load is applied to the front wheel 21 and the rear wheel 22. In this case, the elastic coefficient of the suspension for the rear wheel 22 may be greater than the elastic coefficient of the suspension for the front wheel 21. The possible stroke range of the suspension for the rear wheel 22 may also be smaller than the possible stroke range of the suspension for the front wheel 21.

[0037] The upper end of the suspension 25 is directly or indirectly connected to the body frame 18. The lower end of the suspension 25 is directly or indirectly connected to a member that supports the axle of the corresponding front wheel 21. In this embodiment, a bracket B2 that protrudes upward from the body frame 18 is fixed to the body frame 18. The upper end of the suspension 25 is attached to the bracket B2. The lower end of the suspension 25 is attached directly or indirectly to a housing of the electric motor 24 that is coupled to the corresponding front wheel 21. Since the upper end of the suspension 25 is located higher than the body frame 18, the possible stroke range of the suspension 25 is prevented from becoming too small. Note that the upper end of the suspension 25 does not have to be located higher than the body frame 18.

[0038] The stroke axis of the suspension 25 is inclined relative to the vertical direction, which prevents the length of the suspension 25 from being extremely short and prevents the possible stroke range of the suspension 25 from becoming too small.

[0039] The upper end of the link 26 is directly or indirectly connected to the body frame 18. The lower end of the link 26 is directly or indirectly connected to a member that supports the axle of the corresponding rear wheel 22. As an example, the upper end of the link 26 is also attached to bracket B2. The upper end of the link 26 is located higher than the body frame 18. The lower end of the link 26 is directly or indirectly attached to the housing of the electric motor 24 that is coupled to the corresponding rear wheel 22. Note that the upper end of the link 26 does not have to be located higher than the body frame 18.

[0040] Bracket B2 is fixed to the center of body frame 18 in the longitudinal direction of traveling robot 1. That is, bracket B2 is located behind front wheels 21 and in front of rear wheels 22. Both the upper end of suspension 25 and the upper end of link 26 are attached to bracket B2. This allows both suspension 25 and link 26 to share one bracket B2. Furthermore, external forces input from front wheels 21 and rear wheels 22 can be concentrated at bracket B2 fixed to the center of body frame 18, thereby stabilizing the posture of traveling robot 1.

[0041] The suspension 25 extends obliquely upward and rearward relative to the vertical direction, and the link 26 extends obliquely upward and forward relative to the vertical direction. Therefore, the body frame 18 can be positioned low so as to be close to the wheels 20, and the capacity of the cargo bed 12 can be increased without extremely shortening the lengths of the suspension 25 and the link 26.

[0042] FIG. 3 is a schematic plan view including the wheels 20 and the power receiving interface 14 of the traveling robot 1 of FIG. 1. As shown in FIG. 3, an insertion hole H is provided in the bottom surface of the recess R of the lower cover 13. The power receiving interface 14, which is a connector, is exposed to the outside of the lower cover 13 through the insertion hole H and is disposed in the recess R. In a plan view of the traveling robot 1, a center line L connecting the overall center C1 of the pair of left and right front wheels 21 and the overall center C2 of the pair of left and right rear wheels 22 extends in the front-to-rear direction of the traveling robot 1. In a plan view of the traveling robot 1, the power receiving interface 14 is disposed on the center line L. Note that, for example, if there is one front wheel and two rear wheels 22, the center line L may be a line connecting the center of the front wheel 21 and the overall center of the pair of left and right rear wheels 22.

[0043] The power receiving interface 14 is disposed at the center of the rear part of the body 11 in the left-right direction of the traveling robot 1. The rear wheel 22 is the wheel that is closest to the power receiving interface 14 among all the wheels 20 in the horizontal direction. Specifically, the power receiving interface 14 is disposed rearward of the electric motor 24 that is adjacent to the rear wheel 22 and drives the rear wheel 22. More specifically, the power receiving interface 14 is disposed rearward of the rear wheel 22. Note that the power receiving interface 14 may be disposed at a position other than the rear part of the body 11. For example, if the power receiving interface 14 is disposed at the front part of the body 11, the wheel that is closest to the power receiving interface 14 among all the wheels 20 in the horizontal direction is the front wheel 21.

[0044] Fig. 4 is a block diagram of the running robot 1 of Fig. 1. As shown in Fig. 4, the running robot 1 includes a processing circuit 30, a touch panel display 15, a distance measurement sensor 16, a communication interface 34, a battery 23, an electric motor 24, a power receiving interface 14, wheels 20, etc. The devices 15, 16, 34, and 24 are electrically connected to the processing circuit 30.

[0045] The processing circuit 30 includes a processor 31, a system memory 32, and a storage memory 33. The processor 31 may include a CPU. The system memory 32 may include RAM. The storage memory 33 may include a hard disk, a flash memory, or a combination thereof. The storage memory 33 stores a control program P. A configuration in which the processor 31 executes the control program P read from the storage memory 33 to the system memory 32 is an example of the processing circuit 30. The processor 31 controls at least one of the touch panel display 15 and the electric motor 24 according to the control program P based on information input from at least one of the touch panel display 15, the distance measurement sensor 16, the communication interface 34, etc.

[0046] The touch panel display 15 is an example of a user interface. That is, the touch panel display 15 functions as both a user input interface and a user output interface. The user input interface may be a keyboard or a mouse, or may be a smartphone or tablet terminal capable of communicating with the traveling robot 1. The user output interface may be a non-touch panel display.

[0047] The ranging sensor 16 measures the distance around the running robot 1 in three dimensions to detect the shape of the surroundings of the running robot 1 in three dimensions. The ranging sensor 16 detects the position data of the outer surfaces of obstacles around the running robot 1 by receiving reflected waves from obstacles around the running robot 1. The ranging sensor 16 may be, for example, a LiDAR (Light Detection and Ranging) sensor, but it may also be an infrared ranging sensor, millimeter-wave radar, or a depth-sensing camera. The processing circuit 30 acquires map data of the location where the running robot 1 is traveling and matches the shape of the surroundings detected by the ranging sensor 16 with the shape of the map data to identify the position of the running robot 1 on the map data. In other words, a positioning sensor is realized by combining the ranging sensor 16 with software that matches the shape detected by the ranging sensor 16 with the map data.

[0048] Instead of the distance sensor 16, a satellite positioning sensor such as a GPS sensor may be used as the positioning sensor of the mobile robot 1. The position of the mobile robot 1 may be determined by calculating the distance from each wireless access point to the mobile robot 1 based on the strength of each radio wave received by the mobile robot 1 from each wireless access point installed in the mobile area of ​​the mobile robot 1. Instead of receiving radio waves from multiple wireless access points for positioning, the mobile robot 1 may receive sound waves, light, or magnetism from multiple locators installed in the mobile area. If the mobile robot 1 is remotely controlled to move, the positioning function may not be required.

[0049] The communication interface 34 is an interface for wirelessly connecting to a communication network such as the Internet. The communication interface 34 can function as a transmitter that transmits information about the traveling robot 1 to a server via the communication network, and can also function as a receiver that receives information about other traveling robots 1 transmitted from the server.

[0050] The battery 23 is charged by power supplied from an external charging device 50 (described later) via the power receiving interface 14. The battery 23 supplies power to the processing circuit 30, the touch panel display 15, the distance measurement sensor 16, the communication interface 34, the electric motor 24, etc.

[0051] The electric motor 24 may have a built-in inverter, or the inverter may be external to the electric motor 24. The number of electric motors 24 is the same as the number of wheels 20, and each electric motor 24 independently controls the corresponding wheel 20, but the number of electric motors 24 may be less than the number of wheels 20, and one electric motor 24 may drive multiple wheels 20.

[0052] FIG. 5 is a diagram illustrating the charging operation of the traveling robot 1 of FIG. 1. As shown in FIG. 5, the battery 23 (see FIG. 2) of the traveling robot 1 is charged with power from an external charging device 50. The external charging device 50 includes a power source 51 and a power supply interface 52 electrically connected to the power source 51. The power supply interface 52 is fixed to a wall surface 53 that is placed relative to the ground and is exposed in the area where the traveling robot 1 can travel. The power supply interface 52 is provided at a predetermined height relative to the ground. In this embodiment, the height of the power supply interface 52 above the ground is fixed.

[0053] In this embodiment, the power supply interface 52 is a connector. That is, by mating the power supply interface 52, which is a connector, with the power receiving interface 14, which is also a connector, the battery 23 can be charged. The power supply interface 52 includes a connector housing 52a that protrudes horizontally from the wall surface 53 in the travelable area, and a power transmission contact 52b that is housed in the connector housing 52a and electrically connected to the power source 51. Specifically, the power transmission contact 52b may be a metal terminal electrically connected to the power source 51.

[0054] The power receiving interface 14 of the traveling robot 1 when the loading platform 12 is empty is positioned at a height that allows it to move horizontally to fit into the power supply interface 52 of the external charging device 50. In this embodiment, the height above ground of the center of the power receiving interface 14 of the traveling robot 1 when the loading platform 12 is empty is the same as the height above ground of the center of the power supply interface 52 of the external charging device 50. However, a height error is allowed within a range that allows the power receiving interface 14 to fit into the power supply interface 52.

[0055] When the processing circuit 30 of the traveling robot 1 determines that the battery 23 needs to be charged, it controls the electric motor 24 so that the power receiving interface 14 approaches the power supply interface 52 of the external charging device 50, causing the traveling robot 1 to travel backward. Then, the power receiving interface 14 of the traveling robot 1 fits horizontally into the power supply interface 52 of the external charging device 50. As a result, the power receiving contact 14b of the power receiving interface 14 of the traveling robot 1 properly contacts the power transmitting contact 52b of the power supply interface 52 of the external charging device 50, and the battery 23 is charged by contact power supply.

[0056] At this time, if a large amount of luggage is loaded on the loading platform 12, the suspension 25 may compress, lowering the ground clearance of the front of the body frame 18. However, because there is no suspension between the rear wheels 22 and the body frame 18, the ground clearance of the rear of the body frame 18 hardly changes, and as a result, the ground clearance of the power receiving interface 14 hardly changes. Therefore, when the mobile robot 1 moves backward so as to approach the power supply interface 52 located at a fixed height, the power receiving interface 14 of the mobile robot 1 is properly aligned with the power supply interface 52. This allows the mobile robot 1 to have good off-road performance while stabilizing its charging operation.

[0057] In the present embodiment, the power receiving interface 14 and the power supply interface 52 are properly fitted together when the height above ground of the center of the power receiving interface 14 is the same as the height above ground of the center of the power supply interface 52, but this is not limiting. For example, a configuration may be employed in which the power transmitting contacts of the power supply interface 52 are exposed downward, and the power receiving contacts of the power receiving interface 14, which is positioned slightly lower than the power supply interface 52, are exposed upward, and the interfaces 14 and 52 are slidably connected in the horizontal direction so that the power receiving contacts come into contact with the power transmitting contacts.

[0058] Figure 6 is a vertical cross-sectional view illustrating the angle of the loading surface 12a of the loading platform 12 of the traveling robot 1 in Figure 1. As shown by the two-dot chain line in Figure 6, when the loading platform 12 of the traveling robot 1 is empty, the loading surface 12a of the loading platform 12 is inclined with respect to the imaginary horizontal plane P so that the front part is higher than the rear part. Specifically, the loading surface 12a is inclined upward with respect to the imaginary horizontal plane P in a direction D (see Figure 3) from the overall center C2 of the pair of rear wheels 22 toward the overall center C1 of the pair of front wheels 21.

[0059] When luggage is placed on the loading surface 12a of the cargo bed 12, a downward load is applied to the vehicle body 11, causing the suspension 25 (see FIG. 2) to contract. Therefore, when luggage is loaded on the cargo bed 12, the front part of the loading surface 12a descends together with the vehicle body frame 18 (see FIG. 2), causing the loading surface 12a to approach horizontal, allowing the luggage to be stably placed on the loading surface 12a.

[0060] FIG. 7 is a drawing of the first modified example, equivalent to FIG. 5. Note that components of the first modified example that are common to the above-described embodiment are denoted by the same reference numerals, and a description thereof will be omitted. As shown in FIG. 7, in the first modified example, the battery 23 (see FIG. 2) is charged by contactless power supply between coils that are horizontally opposed to each other. The power receiving interface 114 of the traveling robot 101 includes a casing 114a made of a magnetically permeable material and a power receiving coil 114b housed in the casing 114a and electrically connectable to the battery 23 (see FIG. 2). The power supply interface 152 of the external charging device 150 includes a casing 152a made of a magnetically permeable material and a power transmitting coil 152b housed in the casing 152a and electrically connected to the power source 51. The power receiving interface 114 is positioned at a height that overlaps the height range of the rear wheels 22. Specifically, at least a portion of the power receiving coil 114a (described later) of the power receiving interface 114 is positioned at a height that overlaps the height range of the rear wheels 22.

[0061] Even with this configuration, if the traveling robot 101 moves backward so as to approach the power supply interface 152 located at a predetermined height above the ground, the power receiving coil 114b of the traveling robot 101 will appropriately face the power transmitting coil 152b horizontally, allowing stable charging of the battery 23 by contactless power supply. The other configurations are the same as those of the previously described embodiment, and therefore will not be described again. The previously described configuration variations of the contact-powered traveling robot 1 can also be similarly applied to the contactless power supply type power receiving interface 114.

[0062] FIG. 8 is a drawing of the second modified example, equivalent to FIG. 5. Note that components of the second modified example that are common to the above-described embodiment are assigned the same reference numerals, and descriptions thereof will be omitted. As shown in FIG. 8, in the second modified example, the battery 23 (see FIG. 2) is charged by contactless power supply between coils that are vertically opposed to each other. The power receiving interface 214 of the traveling robot 201 has a casing 214a made of a magnetically permeable material and a power receiving coil 214b that is housed in the casing 214a and can be electrically connected to the battery 23 (see FIG. 2). The power supply interface 252 of the external charging device 250 has a casing 252a made of a magnetically permeable material and a power transmitting coil 252b that is housed in the casing 252a and electrically connected to the power source 51.

[0063] Even with this configuration, if the traveling robot 201 moves backward so as to approach the power supply interface 252 located at a predetermined height above the ground, the power receiving coil 214b of the traveling robot 201 will be aligned vertically with the power transmitting coil 252b, and the battery 23 can be stably charged by contactless power supply. The other configurations are the same as those of the previously described embodiment, and therefore will not be described again. The previously described configuration variations of the contact-powered traveling robot 1 can also be similarly applied to the contactless power supply power receiving interface 214.

[0064] FIG. 9 is a drawing of the third modified example, equivalent to FIG. 3. Note that components of the third modified example that are common to the above-described embodiment are assigned the same reference numerals and will not be described again. As shown in FIG. 9, in the third modified example, the running robot 301 has six wheels 20. The wheels 20 include a pair of front wheels 21 aligned in the left-right direction of the running robot 301, a pair of rear wheels 22 aligned in the left-right direction of the running robot 1, and a pair of center wheels 27 positioned between the front wheels 21 and rear wheels 22 in the front-to-rear direction of the running robot 1 and aligned in the left-to-right direction of the running robot 1. In this embodiment, the front wheels 21 correspond to one wheel, the rear wheels 22 correspond to the other wheel, and the center wheels 27 are drive wheels. When the front-to-rear direction of the running robot 301 is defined as a first direction, a second direction perpendicular to the first direction is the left-to-right direction of the running robot 301.

[0065] The rear wheels 22 are not provided with suspensions, but rather with the aforementioned links 26. The front wheels 21 and central wheels 27 are provided with the aforementioned suspensions 25. The front wheels 21 and central wheels 27 correspond to the first wheels, and the rear wheels 22 correspond to the second wheels. That is, the first wheels include multiple rows of wheels aligned in the front-to-rear direction. An electric motor 24 is connected to the central wheels 27. The front wheels 21 and rear wheels 22 are driven wheels. The driven wheels may be casters or omniwheels. The rear wheels 22 are the wheels that are closest to the power receiving interface 14 of all the wheels 20 in the horizontal direction. Specifically, the power receiving interface 14 is arranged rearward of the rear wheels 22. Note that other configurations are the same as those in the above-described embodiment, and therefore description thereof will be omitted.

[0066] According to this configuration, stable running is achieved with six wheels 20, while costs can be reduced by reducing the number of electric motors 24 for the drive wheels compared to the total number of wheels 20. Note that a suspension may be provided on either the front wheels 21 or the central wheels 27, while the other of the front wheels 21 or the central wheels 27 may be provided with the above-mentioned link 26 without a suspension. Also, one of the front wheels 21 or the rear wheels 22 may be a driven wheel, while the other of the front wheels 21 or the rear wheels 22 may be a drive wheel.

[0067] FIG. 10 is a drawing of the fourth modified example, equivalent to FIG. 3. Note that components of the fourth modified example that are common to the above-described embodiment are assigned the same reference numerals and will not be described again. As shown in FIG. 10, in the fourth modified example, the traveling robot 401 has four wheels 20. The wheels 20 include one front wheel 21, one rear wheel 22, and a pair of center wheels 27 arranged between the front wheel 21 and the rear wheel 22 and aligned in the left-right direction of the traveling robot 1. These wheels 20 are arranged at positions forming vertices of a diamond in a plan view. In this embodiment, the front wheel 21 corresponds to one wheel, the rear wheel 22 corresponds to the other wheel, and the center wheel 27 is a drive wheel. Furthermore, when the longitudinal direction of the traveling robot 401 is defined as a first direction, a second direction perpendicular to the first direction is the left-right direction of the traveling robot 401.

[0068] The rear wheels 22 are not provided with suspensions, but rather with the aforementioned links 26. The front wheels 21 and central wheels 27 are provided with the aforementioned suspensions 25. The front wheels 21 and central wheels 27 correspond to the first wheels, and the rear wheels 22 correspond to the second wheels. That is, the first wheels include multiple rows of wheels aligned in the front-to-rear direction. An electric motor 24 is connected to the central wheels 27. The front wheels 21 and rear wheels 22 are driven wheels. The driven wheels may be casters or omniwheels. The rear wheels 22 are the wheels that are closest to the power receiving interface 14 of all the wheels 20 in the horizontal direction. Specifically, the power receiving interface 14 is arranged rearward of the rear wheels 22. Note that other configurations are the same as those in the above-described embodiment, and therefore description thereof will be omitted.

[0069] According to this configuration, stable running is achieved with the four wheels 20, while costs can be reduced by reducing the number of electric motors for the drive wheels compared to the total number of wheels 20. Note that a suspension may be provided on either the front wheels 21 or the central wheels 27, while the other of the front wheels 21 or the central wheels 27 may be provided with the above-mentioned link 26 without a suspension. Also, one of the front wheels 21 or the rear wheels 22 may be a driven wheel, while the other of the front wheels 21 or the rear wheels 22 may be a drive wheel.

[0070] As described above, the above-described embodiments have been described as examples of the technology disclosed in this application. However, the technology of the present disclosure is not limited to these embodiments and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, the components described in the above-described embodiments can be combined to create new embodiments. For example, some configurations or methods in one embodiment may be applied to other embodiments, and some configurations in one embodiment may be separated from other configurations in that embodiment and extracted as desired. Furthermore, the components described in the accompanying drawings and detailed description include not only components essential for solving the problem, but also components that are not essential for solving the problem, and are used to illustrate the technology.

[0071] The functions of the elements disclosed herein can be performed using circuits or processing circuits, including general-purpose processors, special-purpose processors, integrated circuits, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), graphics processing units (GPUs), conventional circuits, and / or combinations thereof, configured or programmed to perform the disclosed functions. Processors are considered processing circuits or circuits because they include transistors and other circuitry. In this disclosure, a circuit, unit, or means is hardware that performs the recited functions or hardware that is programmed to perform the recited functions. The hardware may be hardware disclosed herein or other known hardware that is programmed or configured to perform the recited functions. Where the hardware is a processor, which is considered a type of circuit, the circuit, means, or unit is a combination of hardware and software, and the software is used to configure the hardware and / or processor.

[0072] [Aspect] The above-described embodiments are examples of the following aspects.

[0073] (Aspect 1) a plurality of wheels including at least one first wheel and at least one second wheel; a vehicle body supported by the plurality of wheels; A battery, a power receiving interface mounted on the vehicle body, electrically connectable to the battery, and configured to receive power energy from a power supply interface of an external charging device; and at least one suspension interposed between the at least one first wheel and the vehicle body, the second wheel is the wheel closest to the power receiving interface in the horizontal direction among the plurality of wheels; a running robot, wherein the second wheel is coupled to the car body so that when the same upward load is applied to the first wheel and the second wheel, the amount of vertical relative displacement between the second wheel and the car body is smaller than the amount of vertical relative displacement between the first wheel and the car body.

[0074] With this configuration, the suspension is interposed between the first wheel and the body, improving the running performance of the mobile robot. Meanwhile, the amount of vertical relative displacement between the second wheel and the body is smaller than the amount of vertical relative displacement between the first wheel and the body, reducing fluctuations in the height above ground of the power receiving interface located near the second wheel. Therefore, by running the mobile robot so as to approach a power supply interface located at a predetermined height above ground, the power receiving interface of the mobile robot can be properly aligned with the power supply interface. As a result, the mobile robot's running performance can be improved while stabilizing its charging operation.

[0075] (Aspect 2) 2. The running robot of claim 1, wherein the second wheel is coupled to the body without a suspension.

[0076] With this configuration, because there is no suspension between the second wheel and the vehicle body, the portion of the vehicle body close to the second wheel is prevented from displacing vertically, thereby preventing fluctuations in the height above ground of the power receiving interface located near the second wheel.

[0077] (Aspect 3) the power receiving interface is mounted on the rear of the vehicle body while facing rearward of the traveling robot; 3. The running robot according to aspect 1 or 2, wherein the at least one second wheel is at least one rear wheel arranged rearward of the first wheel in the front-to-rear direction of the running robot.

[0078] With this configuration, a suspension is provided on the first wheel, which passes over road surface steps before the second wheel when the running robot is moving forward, thereby maintaining good running performance of the running robot when moving forward.

[0079] (Aspect 4) the at least one first wheel is a pair of front wheels aligned in the left-right direction of the traveling robot, the at least one second wheel is a pair of rear wheels aligned in the left-right direction, 4. The traveling robot according to claim 3, wherein the power receiving interface is disposed at the center of the rear of the vehicle body in the left-right direction.

[0080] This configuration allows the vehicle body balance to be maintained in a good condition.

[0081] (Aspect 5) the plurality of wheels include a plurality of drive wheels arranged in a first direction, and one wheel and another wheel sandwiching the drive wheels in a second direction perpendicular to the first direction, At least one wheel selected from the one wheel and the other wheel is a driven wheel, the first wheel is at least one selected from the one wheel and the drive wheel, Aspect 5. The traveling robot according to any one of aspects 1 to 4, wherein the second wheel is the other wheel.

[0082] According to this configuration, by arranging one wheel, multiple central wheels, and the other wheel, and using the central wheel as the drive wheel, stable driving can be achieved while reducing the number of electric motors for the drive wheels compared to the total number of wheels, thereby reducing costs.

[0083] (Aspect 6) A traveling robot according to any one of aspects 1 to 5, wherein the power receiving interface is suspended from the car body, positioned below the car body, and positioned at a height that overlaps the height range of the second wheel.

[0084] This configuration allows the space below the vehicle body to be used effectively to place the power receiving interface. Furthermore, because there is no suspension between the second wheel and the vehicle body, fluctuations in the height of the power receiving interface above the ground are prevented, so even if the power receiving interface is placed at a height that overlaps the height range of the second wheel, the power receiving interface can be prevented from interfering with the ground.

[0085] (Aspect 7) the power supply interface includes a power transmission contact for contactless power supply; A traveling robot according to any one of aspects 1 to 6, wherein the power receiving interface includes a power receiving contact that can be electrically connected to the battery.

[0086] With this configuration, if the traveling robot moves so as to approach the power transmission contact located at a predetermined height above the ground, the power receiving contact of the traveling robot will come into proper contact with the power transmission contact of the external charging device, and the battery can be stably operated through contact power supply.

[0087] (Aspect 8) the power supply interface includes a power transmission coil for contactless power supply; A traveling robot according to any one of aspects 1 to 7, wherein the power receiving interface includes a receiving coil electrically connectable to the battery.

[0088] With this configuration, when the mobile robot moves close to a power transmission coil placed at a predetermined height above the ground, the mobile robot's power receiving coil is properly aligned with the power transmission coil, allowing the battery to be charged stably via contactless power supply.

[0089] (Aspect 9) a loading platform provided on the vehicle body and having a loading surface on which luggage can be placed, A traveling robot according to any one of aspects 1 to 8, wherein, when the loading platform is empty, the loading surface is inclined upward with respect to an imaginary horizontal plane in a direction from the center of the entirety of the at least one second wheel toward the center of the entirety of the at least one first wheel.

[0090] With this configuration, when a load is placed on the loading surface, a downward load is applied to the vehicle body and the suspension compresses, causing the loading surface to approach horizontal, thereby enabling the load to be placed stably on the loading surface. [Explanation of symbols]

[0091] 1. Running robot 11 Body 12 Cargo bed 12a Loading surface 13 Lower cover 14,114,214 Power receiving interface 14b Power receiving contact 18 Body frame 20 wheels 21 Front wheel 22 rear wheel 23 Battery 24 Electric Motor 25 Suspension 26 Links 50 External charging device 51 Power supply 52, 152, 252 power supply interface 52b Power transmission contact 114b, 214b receiving coil 152b, 252b Transmitting coil C1, C2 center D direction P Virtual horizontal plane

Claims

1. a plurality of wheels including at least one first wheel and at least one second wheel; a vehicle body supported by the plurality of wheels; A battery, a power receiving interface mounted on the vehicle body, electrically connectable to the battery, and configured to receive power energy from a power supply interface of an external charging device; at least one suspension interposed between the at least one first wheel and the vehicle body; the second wheel is a wheel of the plurality of wheels that is closest to the power receiving interface in a horizontal direction; a running robot, wherein the second wheel is coupled to the car body so that when the same upward load is input to the first wheel and the second wheel, the amount of vertical relative displacement between the second wheel and the car body is smaller than the amount of vertical relative displacement between the first wheel and the car body.

2. the number of the suspensions is less than the total number of the plurality of wheels; The running robot according to claim 1 , wherein the second wheel is coupled to the body without a suspension.

3. the power receiving interface is mounted on the rear of the vehicle body while facing rearward of the traveling robot; The running robot according to claim 1 , wherein the at least one second wheel is at least one rear wheel arranged rearward of the first wheel in a longitudinal direction of the running robot.

4. the at least one first wheel is a pair of front wheels aligned in a left-right direction of the running robot, the at least one second wheel is a pair of rear wheels aligned in the left-right direction, The traveling robot according to claim 3 , wherein the power receiving interface is disposed at the center of the rear portion of the body in the left-right direction.

5. the plurality of wheels include a plurality of drive wheels arranged in a first direction, and one wheel and another wheel sandwiching the drive wheels in a second direction perpendicular to the first direction, At least one wheel selected from the one wheel and the other wheel is a driven wheel, the first wheel is at least one selected from the one wheel and the drive wheel, The running robot according to claim 1 , wherein the second wheel is the other wheel.

6. The traveling robot according to claim 1 , wherein the power receiving interface is suspended from the car body and positioned below the car body at a height that overlaps with a height range of the second wheel.

7. the power supply interface includes a power transmission contact for contactless power supply; The running robot according to claim 1 , wherein the power receiving interface includes a power receiving contact that is electrically connectable to the battery.

8. the power supply interface includes a power transmission coil for contactless power supply; The running robot according to claim 1 , wherein the power receiving interface includes a receiving coil electrically connectable to the battery.

9. The vehicle further includes a loading platform provided on the vehicle body, the loading platform including a loading surface on which luggage can be placed, 5. The traveling robot according to claim 1, wherein, when the loading platform is empty, the loading surface is inclined upward with respect to an imaginary horizontal plane in a direction from the center of the entirety of the at least one second wheel toward the center of the entirety of the at least one first wheel.

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