Vehicle and driving device therefor

Abstract

[Problem] To provide a vehicle and a driving device therefor which are excellent in terms of traveling performance. [Solution] Provided is a vehicle including: a plurality of driving wheels installed in a main body and configured so that each driving wheel rotates in at least one among a left direction and a right direction; and a plurality of electric motors respectively provided for a corresponding driving wheel among the plurality of driving wheels and configured to generate driving torque for rotating each corresponding driving wheel in at least one among a forward direction and a rearward direction.

Description

Vehicle and its drive system

[0001] The present disclosure relates to a vehicle including multiple drive wheels.

[0002] Conventionally, vehicles using so-called in-wheel motor systems, in which wheels are directly driven by electric motors such as motors, have been known. For example, Patent Document 1 describes a towing vehicle 12 equipped with in-wheel motors 32L, 32R as braking / driving units that apply independent braking / driving forces to left and right wheels 22L, 22R. In this type of towing vehicle 12, the left and right in-wheel motors 32L, 32R are independently controllable, and the turning operation of the towing vehicle 12 can be controlled by providing a difference in torque between the left and right in-wheel motors 32L, 32R.

[0003] JP 2023-183869 A

[0004] In light of the above-described techniques, the present disclosure aims to provide a vehicle and a drive device thereof with superior driving performance through various embodiments.

[0005] According to one aspect of the present disclosure, there is provided a vehicle including "a plurality of drive wheels mounted on a main body, each configured to rotate in at least one of a left direction and a right direction, and a plurality of electric motors provided for each corresponding one of the plurality of drive wheels, each configured to generate a drive torque that rotates each corresponding drive wheel in at least one of a forward direction and a backward direction."

[0006] According to one aspect of the present disclosure, there is provided a drive device including: a plurality of drive wheels configured so that each drive wheel rotates in at least one of a left direction and a right direction; and a plurality of electric motors provided for each corresponding drive wheel among the plurality of drive wheels and configured to generate drive torque that rotates each corresponding drive wheel in at least one of a forward direction and a backward direction.

[0007] According to various embodiments of the present disclosure, it is possible to provide a vehicle and a drive device thereof with superior driving performance.

[0008] It should be noted that the above effects are merely illustrative for the sake of convenience and are not limiting. In addition to or instead of the above effects, any effect described in this disclosure or an effect obvious to a person skilled in the art may be achieved.

[0009] FIG. 1 is a perspective view illustrating an example of a configuration of a vehicle 1 according to an embodiment of the present disclosure. FIG. 2 is a plan view illustrating an example of a configuration of the vehicle 1 according to an embodiment of the present disclosure. FIG. 3 is a block diagram illustrating a configuration of the vehicle 1 according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating a processing flow executed by a control device 100 of the vehicle 1 according to an embodiment of the present disclosure. FIG. 5 is a plan view illustrating a configuration of a drive device 200 of the vehicle 1 according to an embodiment of the present disclosure. FIG. 6A is an explanatory diagram illustrating, in a simplified manner, a turning state of the vehicle 1 according to an embodiment of the present disclosure. FIG. 6B is an explanatory diagram illustrating, in a simplified manner, a turning state of the vehicle 1 according to an embodiment of the present disclosure. FIG. 7 is a perspective view illustrating a configuration of a wheel mechanism 250 of the vehicle 1 according to an embodiment of the present disclosure. FIG. 8 is a perspective view illustrating a configuration of the wheel mechanism 250 of the vehicle 1 according to an embodiment of the present disclosure. FIG. 9 is a perspective view illustrating a configuration of a knuckle device 220 of the vehicle 1 according to an embodiment of the present disclosure. FIG. 10A is a perspective view illustrating a partial configuration of the knuckle device 220 of the vehicle 1 according to an embodiment of the present disclosure. FIG. 10B is a perspective view illustrating a partial configuration of the knuckle device 220 of the vehicle 1 according to an embodiment of the present disclosure. Fig. 11 is a perspective view showing the configuration of the main body 300 of the vehicle 1 according to an embodiment of the present disclosure. Fig. 12 is a side view showing a state in which the carrier 900 is connected to the vehicle 1 according to an embodiment of the present disclosure. Fig. 13 is a perspective view showing the configuration of the carrier 900 connected to the vehicle 1 according to an embodiment of the present disclosure.

[0010] 1. Configuration of Vehicle 1 A vehicle according to the present disclosure has a plurality of drive wheels mounted on a main body. More specifically, the vehicle has a plurality of drive wheels configured to rotate in at least one of a left direction and a right direction. This allows the vehicle to turn in at least one of a left direction and a right direction. The vehicle also has a plurality of electric motors provided on corresponding ones of the plurality of drive wheels and configured to generate drive torque that rotates each corresponding drive wheel in at least one of a forward direction and a backward direction. This allows the vehicle to travel in at least one of a forward direction and a backward direction.

[0011] Such vehicles are used, for example, to carry and transport at least one of animals, including humans, and goods, or to tow and transport at least one of animals, including humans, and goods. The vehicles are preferably used to transport animals, such as humans, livestock, and pets, as well as goods, such as agricultural crops, agricultural materials (e.g., seeds, fertilizers, feed, pesticides, or packaging materials), agricultural equipment, industrial products, industrial materials, industrial equipment, experimental and testing materials, experimental and testing equipment, merchandise, commercial materials, and deliveries, and more preferably to transport agricultural crops, agricultural materials (e.g., seeds, fertilizers, feed, pesticides, or packaging materials) and agricultural equipment. The animals and goods exemplified here are merely examples of things that can be transported by the vehicle, and other things may naturally be transported. Furthermore, carrying and towing are merely examples of transportation methods, and other methods of transportation may naturally be used.

[0012] The vehicle can be used not only on Earth but also in outer space. The vehicle can be used both indoors and outdoors. The vehicle can be used on both smooth and rough terrain. For example, such a vehicle can be used in paddy fields, fields, orchards, grain farms, pastures, forests, construction sites, disaster areas, factories, buildings, apartment buildings, or ordinary houses, and is preferably used in work areas such as paddy fields, fields, orchards, grain farms, pastures, construction sites, disaster areas, or factories, more preferably in agricultural areas such as paddy fields, fields, orchards, grain farms, or pastures, and particularly preferably in orchards. On rough terrain such as orchards, where unevenness, mud, slopes, and other road surfaces require flexible maneuvering by individually controlling the drive wheels, the vehicle has excellent driving performance and can be used effectively.

[0013] FIG. 1 is a perspective view showing an example of the configuration of a vehicle 1 according to an embodiment of the present disclosure. FIG. 1 shows the vehicle 1 including a plurality of drive wheels (left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d) installed on a main body 300, and a plurality of electric motors (electric motors 290a to 290d) provided for each corresponding one of the plurality of drive wheels. That is, the vehicle 1 includes a front drive unit 200a installed at the front of the vehicle 1, a rear drive unit 200b installed at the rear of the vehicle 1, a main body 300 installed on the upper surfaces of the front drive unit 200a and the rear drive unit 200b, and a control device 100 (not shown in FIG. 1 ) for controlling at least one of the front drive unit 200a and the rear drive unit 200b.

[0014] At least one of the front drive unit 200a and the rear drive unit 200b generates a propulsive force for moving the vehicle 1 forward or backward, and also functions as a drive unit capable of turning the vehicle 1 left or right. The front drive unit 200a includes a pair of drive wheels (a left front drive wheel 250a and a right front drive wheel 250b) provided in a direction perpendicular to the direction in which the vehicle 1 moves forward, a knuckle unit 220a connected to the left front drive wheel 250a and for supporting the left front drive wheel 250a, a knuckle unit 220b connected to the right front drive wheel 250b and for supporting the right front drive wheel 250b, a suspension unit 260a connected to the knuckle unit 220a and for absorbing shocks while the vehicle 1 is traveling or while an object to be transported is being placed, and a suspension unit 260b connected to the knuckle unit 220b and for absorbing shocks while the vehicle 1 is traveling or while an object to be transported is being placed. The vehicle includes a suspension device 260b, an electric motor 290a housed within the wheel of the left front driving wheel 250a and generating a driving torque to rotate the left front driving wheel 250a in at least one of a forward direction and a rearward direction, an electric motor 290b housed within the wheel of the right front driving wheel 250b and generating a driving torque to rotate the right front driving wheel 250b in at least one of a forward direction and a rearward direction, and a steering device 280a connected to at least one of the knuckle devices 220a and 220b and for turning the left front driving wheel 250a and the right front driving wheel 250b.

[0015] The rear drive device 200b includes a pair of drive wheels (left rear drive wheel 250c and right rear drive wheel 250d) provided in a direction perpendicular to the direction in which the vehicle 1 moves forward, a knuckle device 220c connected to the left rear drive wheel 250c and supporting the left rear drive wheel 250c, a knuckle device 220d connected to the right rear drive wheel 250d and supporting the right rear drive wheel 250d, a suspension device 260c connected to the knuckle device 220c and absorbing shocks while the vehicle 1 is traveling or while an object to be transported is being placed, and a suspension device 260c connected to the knuckle device 220d and absorbing shocks while the vehicle 1 is traveling or while an object to be transported is being placed. an electric motor 290c housed in the wheel of the left rear driving wheel 250c for generating a driving torque that rotates the left rear driving wheel 250c in at least one of a forward direction and a rearward direction; an electric motor 290d housed in the wheel of the right rear driving wheel 250d for generating a driving torque that rotates the right rear driving wheel 250d in at least one of a forward direction and a rearward direction; and a steering device 280b connected to at least one of the knuckle devices 220c and 220d for turning the left rear driving wheel 250c and the right rear driving wheel 250d.

[0016] Note that Figure 1 illustrates a case in which the steering device 280a is connected to the front drive device 200a and the steering device 280b is connected to the rear drive device 200b, but it is also possible to connect a steering device to only one of the front drive device 200a or the rear drive device 200b and have the vehicle 1 turn using only one of them.

[0017] The main body 300 functions as a main body supported by the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d via the knuckle devices 220a to 220d. In other words, the main body 300 connects the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d, respectively, and constitutes the vehicle 1 integrally with the front drive device 200a and the rear drive device 200b.

[0018] The main body 300 is made of, for example, a metal material such as aluminum, steel, or an alloy thereof, a resin material such as fiber-reinforced resin or hard urethane, or a combination thereof, preferably aluminum or an alloy thereof. By using aluminum or an alloy thereof, it is possible to achieve both lightweight and rigidity.

[0019] The main body 300 includes a main body chassis 310 configured so that its longitudinal direction corresponds to the forward movement of the vehicle 1, and a mounting base 360 ​​installed on the main body chassis 310 so as to be slidable in the longitudinal direction of the main body chassis 310. The front drive unit 200a is connected to the front of the main body chassis 310 in the longitudinal direction, and the rear drive unit 200b is connected to the rear of the main body chassis 310 in the longitudinal direction. Specifically, a pair of left front drive wheel 250a and right front drive wheel 250b are arranged symmetrically with respect to each other in front of the main body chassis 310, with the main body chassis 310 in between. Similarly, a pair of left rear drive wheel 250c and right rear drive wheel 250d are arranged symmetrically with respect to each other in rear of the main body chassis 310, with the main body chassis 310 in between.

[0020] As described above, the mounting platform 360 is connected to the main chassis 310 so as to slide along the longitudinal direction of the main chassis 310. In other words, the mounting platform 360 can be moved and installed at any position along the longitudinal direction of the main chassis 310. The mounting platform 360 has a horizontally elongated plate-like structure extending along the short side of the main chassis 310. Typically, a carrier platform on which an animal or object to be transported can be placed is installed on top of the horizontally elongated plate-like mounting platform 360. In addition to the carrier platform, various accessory devices such as a pesticide sprayer, a cultivator, a lawnmower, or a combination of these may be installed on the mounting platform 360.

[0021] Fig. 2 is a plan view showing an example of the configuration of a vehicle 1 according to an embodiment of the present disclosure. Specifically, Fig. 2 is a view showing the configuration when the vehicle 1 is viewed from above. According to Fig. 2, a front drive unit 200a is connected to the front of a main body chassis 310 of the main body 300 in the longitudinal direction, and a rear drive unit 200b is connected to the rear of the front drive unit 200a in the longitudinal direction. A left front drive wheel 250a and a right front drive wheel 250b are respectively installed on the left and right sides of the main body chassis 310, symmetrically sandwiching the main body chassis 310.

[0022] Here, left front drive wheel 250a includes a rubber tire (although the material may be other than rubber) that has elasticity to contact the road, and a cylindrical metal wheel (although the material may be other than metal) on which the tire is mounted. An electric motor 290a is disposed inside the wheel of left front drive wheel 250a. Electric motor 290a is also called an in-wheel motor and functions as a drive force applying unit. That is, electric motor 290a generates a drive torque for rotating left front drive wheel 250a in the forward direction of vehicle 1 (i.e., forward, in the direction indicated by arrow T1 in FIG. 2 ) relative to left front drive wheel 250a, to which electric motor 290a is attached. Similarly, electric motor 290a generates a drive torque for rotating left front drive wheel 250a in the reverse direction of vehicle 1 (i.e., rearward, in the direction indicated by arrow T1 in FIG. 2 ).

[0023] Specifically, the electric motor 290a includes a rotor fixed to the left front drive wheel 250a and a stator fixed to the main body 300 at a position corresponding to the rotor. The stator is arranged in an annular shape around the rotational shaft of the electric motor 290a. The rotational shaft of the electric motor 290a is connected to the rotational shaft of the wheel via members such as bearings and bearings. Therefore, when power is supplied to the stator from the vehicle battery or alternator, the electric motor 290a generates an electromagnetic force between the stator and the rotor, and the rotor rotates around the stator due to this electromagnetic force, thereby generating a drive torque for rotating the left front drive wheel 250a. Note that the structure of the electric motor 290a is merely an example, and it goes without saying that drive torque may be generated by other configurations.

[0024] Similarly, right front drive wheel 250b includes a rubber tire (although the material may be other than rubber) that has elasticity to contact the roadway, and a cylindrical metal wheel (although the material may be other than metal) on which the tire is mounted. An electric motor 290b is disposed inside the wheel of right front drive wheel 250b. Electric motor 290b is also called an in-wheel motor and functions as a drive force applying unit. That is, electric motor 290b generates a drive torque for right front drive wheel 250b, which is installed corresponding to electric motor 290b, to rotate right front drive wheel 250b in the forward direction of vehicle 1 (i.e., forward, in the direction indicated by arrow T2 in FIG. 2 ). Similarly, electric motor 290b generates a drive torque for right front drive wheel 250b, which is installed corresponding to right front drive wheel 250b, to rotate right front drive wheel 250b in the reverse direction of vehicle 1 (i.e., rearward, in the direction indicated by arrow T2 in FIG. 2 ).

[0025] The mechanism by which electric motor 290b generates drive torque for rotating right front drive wheel 250b is the same as that of electric motor 290a, and therefore a description thereof will be omitted.

[0026] The left front driving wheel 250a and the right front driving wheel 250b are connected by a connecting rod 210a that functions as a connecting part, and thereby rotate in conjunction with each other in a direction perpendicular to the forward direction of the vehicle 1 (i.e., at least one of the left direction and the right direction, which are the directions indicated by arrows S1 and S2 in FIG. 2). Specifically, a connecting part 221a that connects the knuckle unit 220a and the suspension unit 260a and serves as the left-right rotation axis of the left front driving wheel 250a, and a connecting part 221b that connects the knuckle unit 220b and the suspension unit 260b and serves as the left-right rotation axis of the right front driving wheel 250b are formed. Connecting rod 210a has a rod-like shape in which the tip of an arm extending from connecting portion 221a in a direction approaching left front driving wheel 250a is connected to the left end of connecting rod 210a, and the tip of an arm extending from connecting portion 221b in a direction approaching right front driving wheel 250b is connected to the right end of connecting rod 210a. Details of the mechanism by which left front driving wheel 250a and right front driving wheel 250b rotate in conjunction with each other in the directions of arrows S1 and S2 will be described later with reference to FIG.

[0027] Furthermore, rear drive unit 200b is provided with a left rear drive wheel 250c and a right rear drive wheel 250d on the left and right sides of main body chassis 310, respectively, so as to be symmetrical with respect to main body chassis 310.

[0028] Here, the left rear drive wheel 250c includes a rubber tire (although the material may be other than rubber) that has elasticity to contact the roadway, and a cylindrical metal wheel (although the material may be other than metal) on which the tire is mounted. An electric motor 290c is disposed inside the wheel of the left rear drive wheel 250c. The electric motor 290c is also called an in-wheel motor and functions as a drive force applying unit. That is, the electric motor 290c generates a drive torque for the left rear drive wheel 250c, which is installed corresponding to the electric motor 290c, to rotate the left rear drive wheel 250c in the forward direction of the vehicle 1 (i.e., the forward direction, indicated by arrow T3 in FIG. 2 ). Similarly, the electric motor 290c generates a drive torque for the left rear drive wheel 250c to rotate the left rear drive wheel 250c in the reverse direction of the vehicle 1 (i.e., the rearward direction, indicated by arrow T3 in FIG. 2 ).

[0029] The mechanism by which electric motor 290c generates drive torque for rotating left rear drive wheel 250c is the same as that of electric motor 290a, and therefore a description thereof will be omitted.

[0030] Similarly, the right rear drive wheel 250d includes a rubber tire (although the material may be other than rubber) that has elasticity to contact the roadway, and a cylindrical metal wheel (although the material may be other than metal) on which the tire is mounted. An electric motor 290d is disposed inside the wheel of the right rear drive wheel 250d. The electric motor 290d is also called an in-wheel motor and functions as a drive force applying unit. That is, the electric motor 290d generates a drive torque for the right rear drive wheel 250d, which is installed corresponding to the electric motor 290d, to rotate the right rear drive wheel 250d in the forward direction of the vehicle 1 (i.e., the forward direction, indicated by arrow T4 in FIG. 2 ). Similarly, the electric motor 290d generates a drive torque for the right rear drive wheel 250d, which is installed corresponding to the right rear drive wheel 250d, to rotate the right rear drive wheel 250d in the reverse direction of the vehicle 1 (i.e., the rearward direction, indicated by arrow T4 in FIG. 2 ).

[0031] The mechanism by which electric motor 290d generates drive torque for rotating right rear drive wheel 250d is the same as that of electric motor 290a, and therefore a description thereof will be omitted.

[0032] Left rear drive wheel 250c and right rear drive wheel 250d are connected by connecting rod 210b, which functions as a connecting part, and thereby rotate in conjunction with each other in a direction perpendicular to the forward direction of vehicle 1 (i.e., at least one of the left and right directions, which are the directions indicated by arrows S3 and S4 in FIG. 2). Specifically, a connecting part 221c is formed that connects knuckle unit 220c and suspension unit 260c and serves as the left-right rotation axis of left rear drive wheel 250c, and a connecting part 221d is formed that connects knuckle unit 220d and suspension unit 260d and serves as the left-right rotation axis of right rear drive wheel 250d. Connecting rod 210b has a rod-like shape in which the tip of an arm extending from connecting portion 221c in a direction approaching left rear drive wheel 250c is connected to the left end of connecting rod 210b, and the tip of an arm extending from connecting portion 221d in a direction approaching right rear drive wheel 250d is connected to the right end of connecting rod 210b. Details of the mechanism by which left rear drive wheel 250c and right rear drive wheel 250d rotate in conjunction with each other in the directions of arrows S3 and S4 will be described later with reference to FIG.

[0033] 2, electric motors 290a, 290b, 290c, and 290d are installed to correspond to left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d, respectively. Electric motors 290a, 290b, 290c, and 290d are independently controlled upon receiving control information from control device 100 (not shown in FIG. 2). This allows left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d to be independently rotated in at least one of the forward and backward directions. In this way, by installing an electric motor on each of the left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d and making it possible to control each drive wheel independently, smoother driving is possible, especially on rough roads such as uneven terrain.

[0034] 2, electric motors are provided corresponding to the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d, respectively, but electric motors may be provided only to the left front drive wheel 250a and the right front drive wheel 250b on the front side of the vehicle 1, or only to the left rear drive wheel 250c and the right rear drive wheel 250d on the rear side of the vehicle 1. If no electric motors are provided, the wheels will not function as drive wheels but will simply function as running wheels.

[0035] 2, the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d are configured to rotate in the directions of arrows S1 to S4 in a coordinated manner. However, instead of this, only the left front drive wheel 250a and the right front drive wheel 250b on the front side of the vehicle 1 may rotate in the directions of arrows S1 and S2, and the left rear drive wheel 250c and the right rear drive wheel 250d on the rear side of the vehicle 1 may not rotate in the directions of arrows S3 and S4. Similarly, only the left rear drive wheel 250c and the right rear drive wheel 250d on the rear side of the vehicle 1 may rotate in the directions of arrows S3 and S4, and the left front drive wheel 250a and the right front drive wheel 250b on the front side of the vehicle 1 may not rotate in the directions of arrows S1 and S2.

[0036] In the example shown in FIG. 2, the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d are configured to rotate in the directions of arrows S1 to S4 in a coordinated manner. However, instead of this, the front drive unit 200a including the left front drive wheel 250a and the right front drive wheel 250b, and the rear drive unit 200b including the left rear drive wheel 250c and the right rear drive wheel 250d, may each rotate independently in the directions of arrows S1 and S2 or S3 and S4. This is possible by each drive unit independently receiving control information from the control device 100 and being controlled based on that control information. For example, on rough terrain, the presence of obstacles, bumps, mud, etc. may cause problems with the drive of only one of the drive wheels. However, by configuring in this manner, smoother driving can be achieved.

[0037] 2. Control of Vehicle 1 FIG. 3 is a block diagram showing the configuration of a vehicle 1 according to an embodiment of the present disclosure. Specifically, FIG. 3 is a diagram showing the configuration of a control device 100 for controlling each component of the vehicle 1 and each component controlled by the control device 100. According to FIG. 3, the control device 100 of the vehicle 1 includes a processor 111, a memory 112, an input interface 113, an output interface 114, and a communication interface 115. These components are electrically connected to each other via control lines and data lines. Note that the control device 100 does not need to include all of the components shown in FIG. 3; some components may be omitted, or other components may be added. The control device 100 may be any device capable of communicating with the other components shown in FIG. 3 and other remotely installed processing devices or server devices via a wired or wireless network. For example, a smartphone, tablet, laptop PC, desktop PC, or imaging device may be used.

[0038] The processor 111 functions as a control unit that controls other components of the vehicle 1 based on a processing program stored in the memory 112. Specifically, based on the processing program stored in the memory 112, the processor 111 executes the following processes: "accepting a command input from a user to start driving via the input interface 113," "receiving external environment information from the sensor 600 connected to the control device 100 via the communication interface 115," "generating control information for the vehicle 1 based on the received external environment information," and "transmitting the generated control information via the communication interface 115 to the electric motor 290 (electric motors 290a to 290d) included in the drive device, the steering device 280 (steering device 280a and steering device 280b), the accessory device 800, or a combination thereof." The processor 111 is mainly composed of one or more CPUs, but may also be combined with a GPU, an FPGA, or the like as appropriate.

[0039] The memory 112 is composed of RAM, ROM, non-volatile memory, HDD, SSD, etc., and functions as a storage unit. The memory 112 stores instructions and commands for various controls of the vehicle 1 according to this embodiment as processing programs. Specifically, the memory 112 stores processing programs that the processor 111 executes, such as "a process of receiving an instruction input to start driving from a user via the input interface 113," "a process of receiving external environment information from a sensor 600 connected to the control device 100 via the communication interface 115," "a process of generating control information for the vehicle 1 based on the received external environment information," and "a process of transmitting the generated control information via the communication interface 115 to an electric motor 290 (electric motors 290a to 290d) included in the drive device, a steering device 280 (steering device 280a and steering device 280b), an accessory device 800, or a combination thereof."

[0040] The input interface 113 functions as an input unit that accepts user instruction inputs to the vehicle 1. Examples of the input interface 113 include a steering wheel, a brake pedal, an access pedal, and the like, as well as physical key buttons, a touch panel having an input coordinate system corresponding to the display coordinate system of the display, a mouse, a keyboard, and the like. Note that the input interface 113 does not always need to be physically provided in the control device 100, and may be connected as needed via a wired or wireless network.

[0041] The output interface 114 functions as an output unit for outputting information indicating the driving state of the vehicle 1, external environmental information detected by the sensor 600, and the like. An example of the output interface 114 is a display configured with a liquid crystal panel, an organic EL display, a plasma display, or the like. However, the control device 100 itself does not necessarily need to be equipped with a display. For example, an interface for connecting to a display or the like connectable to the control device 100 via a wired or wireless network can also function as the output interface 114 for outputting display data to the display or the like.

[0042] The communication interface 115 functions as a communication unit for transmitting and receiving various information such as control information to and from the sensor 600, the electric motor 290 (electric motors 290a to 290d), the steering device 280 (steering device 280a and steering device 280b), the accessory device 800, other remotely installed processing devices, server devices, or combinations thereof, all of which are connected via a wired or wireless network. Examples of the communication interface 115 include wired communication connectors such as USB and SCSI, wireless communication transceiver devices for wideband wireless communication such as wireless LAN, Bluetooth (registered trademark), and LTE, infrared, and various connection terminals for printed circuit boards and flexible circuit boards.

[0043] The sensor 600 is communicatively connected to the control device 100 via a communication interface and functions as a detection unit for detecting external environmental information around the main body 300. The external environmental information detected by the sensor is processed by the processor 111 and used to generate control information for the vehicle 1. Therefore, examples of the sensor 600 include a camera (image sensor), an infrared sensor, an ultraviolet sensor, a temperature sensor, a humidity sensor, an acceleration sensor, radar, an ultrasonic sensor, or a combination thereof, and preferably a camera (image sensor), an infrared sensor, an ultraviolet sensor, a radar, an ultrasonic sensor, or a combination thereof. By using such a sensor 600, external environmental information such as obstacles such as people, ladders, agricultural equipment, baskets, fences, posts, rocks, fallen branches, or combinations thereof, and road surface conditions of the road such as unevenness, slopes, mud, or combinations thereof can be detected.

[0044] The electric motors 290 (electric motors 290a to 290d) function as driving force applying units that apply driving torque independently to the correspondingly installed driving wheels (left front driving wheel 250a, right front driving wheel 250b, left rear driving wheel 250c, and right rear driving wheel 250d). That is, the electric motors 290 (electric motors 290a to 290d) adjust the magnitude (strength) and direction of the driving torque applied to each driving wheel based on control information generated by the control device 100.

[0045] Steering device 280 (steering device 280a and steering device 280b) is installed on at least one of front drive device 200a and rear drive device 200b, and functions as a rotation control unit for rotating each drive wheel (left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d) in conjunction with each other in the left and right directions (in the directions of arrows S1 to S4 in FIG. 2). Steering device 280 adjusts the direction and amount of rotation of each drive wheel in order to turn vehicle 1 based on control information generated by control device 100.

[0046] The accessory device 800 is attached to the main body 300 as an attachment, and functions as an accessory part for expanding the functions and uses of the main body 300 or the vehicle 1. Examples of the accessory device 800 include a pesticide sprayer, a cultivator, a grass cutter, or a combination of these. That is, based on the control information generated by the control device 100, it is possible to adjust the start and end of pesticide spraying, the spray direction, and the spray amount.

[0047] Although not specifically shown, a platform 900 can also be installed on the vehicle 1. In this case, the control device 100 can generate control signals for controlling the elevation and tilt of the platform 900.

[0048] Fig. 4 is a diagram showing a processing flow executed by the control device 100 of the vehicle 1 according to an embodiment of the present disclosure. Specifically, Fig. 4 is a diagram showing a processing flow executed by the control device 100 when controlling the traveling of the vehicle 1. The processing flow is mainly performed by the processor 111 of the control device 100 reading and executing a program stored in the memory 112.

[0049] 4, the processor 111 receives an instruction input from the user to start traveling (start moving) via the input interface 113 (S111). As an example of this processing, the processor 111 receives an instruction input from the user via the input interface 113 in response to a start icon displayed on the display via the output interface 114.

[0050] Next, processor 111 generates a control signal for transmitting the vehicle 1 based on the received instruction input (S112). As an example of this processing, processor 111 generates a control signal for each of electric motors 290 (electric motors 290a to 290d) to generate a drive torque for rotating the corresponding drive wheel (left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d) in the forward direction (forward as indicated by arrows T1 to T4 in FIG. 2). Furthermore, if instruction input related to the speed or direction of travel of vehicle 1 is also received as the instruction input in S111, processor 111 generates a control signal for adjusting the magnitude (strength) of the drive torque and the direction and amount by which each drive wheel is rotated in a direction perpendicular to the forward direction.

[0051] Next, the processor 111 transmits the control signal generated in S112 to at least one of the electric motor 290 and the steering device 280 via the communication interface 115 (S113).

[0052] Next, the processor 111 receives external environment information from the sensor 600 via the communication interface 115, for example, periodically at a predetermined interval (S114). As described above, the sensor 600 may be, for example, a camera (image sensor), an infrared sensor, an ultraviolet sensor, a temperature sensor, a humidity sensor, an acceleration sensor, a radar, an ultrasonic sensor, or a combination thereof. That is, the processor 111 receives, as the external environment information, image data, infrared detection data, ultraviolet detection data, temperature, humidity, acceleration, radar reception data, ultrasonic data, or a combination thereof. Note that the external environment information exemplified here is merely an example, and any external environment information usable for generating control information for the vehicle 1 may be used.

[0053] Next, the processor 111 generates control information for moving the vehicle 1 based on the external environment information received in S114 (S115). For example, if an obstacle is detected through the external environment information, the vehicle 1 needs to avoid the obstacle. In such a case, the processor 111 generates a control signal for rotating the drive wheels (left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d) in a coordinated manner in a direction perpendicular to the forward direction so as to turn the vehicle 1 in a direction to avoid the obstacle. Furthermore, for example, if an inclination of the road is detected through the external environment information, it is necessary to control the speed of the vehicle 1 so as not to slow down too much. In such a case, the processor 111 generates a control signal for increasing the drive torque of the electric motors 290 (electric motors 290a to 290d) provided corresponding to the drive wheels (left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d). Furthermore, for example, if it is detected through external environmental information that only the left front drive wheel 250a and the right rear drive wheel 250d are in mud, it is expected that the rotation speed of these drive wheels will slow down. In such a case, the processor 111 generates a control signal to increase the drive torque of the left front drive wheel 250a and the right rear drive wheel 250d.

[0054] Next, the processor 111 transmits the control signal generated in S115 to at least one of the electric motor 290 and the steering device 280 via the communication interface 115 (S116).

[0055] Next, processor 111 determines whether or not an instruction input to end (stop) traveling has been received from the user via input interface 113 (S117). As an example of this processing, processor 111 receives, via input interface 113, an instruction input from the user in response to a stop icon displayed on the display via output interface 114. In this case, processor 111 generates a control signal for stopping, specifically, a control signal for setting the drive torque of electric motor 290 (electric motors 290a to 290d) to zero, and transmits this control signal to electric motor 290 via communication interface 115. This ends the processing flow.

[0056] If the processor 111 determines that the instruction input has not been received, the process returns to S114 and the processor 111 receives the external environment information again. That is, in this case, the external environment information is received at a predetermined interval, so that the vehicle 1 can be automatically controlled.

[0057] 4, it is also possible to control the traveling direction and speed of the vehicle 1 by receiving an operational input from the user via the input interface 113. Also, although not particularly shown in Fig. 4, it is also possible to obtain travel schedule information (e.g., map information) input in advance by the user or the like and control the traveling direction and speed of the vehicle 1 based on the travel schedule information.

[0058] 3. Turning of Vehicle 1 As described with reference to FIG. 2 and other figures, vehicle 1 has electric motors 290a to 290d for supplying drive torque for rotation in the forward and backward directions to the corresponding left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d. That is, vehicle 1 can move in the forward and backward directions by the electric motors connected to each drive wheel. In addition, as described with reference to FIG. 2 and other figures, vehicle 1 has steering devices 280a and 280b for rotating left front drive wheel 250a, right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d in the left and right directions, respectively. That is, vehicle 1 can turn in the left and right directions by the steering devices 280a and 280b.

[0059] Fig. 5 is a plan view showing the configuration of a drive device 200 of a vehicle 1 according to an embodiment of the present disclosure. Specifically, Fig. 5 is a diagram showing operation of a front-side drive device 200a that receives a control signal for turning the vehicle 1 from the control device 100. According to Fig. 5, the front-side drive device 200a includes a steering device 280a configured to be extendable and retractable upon receiving the control signal, a knuckle device 220a connected to one end of the steering device 280a, a connecting rod 210a connected to an end of the knuckle device 220a opposite to the end to which the one end of the steering device 280a is connected, and a knuckle device 220b connected to an end of the connecting rod 210a opposite to the end connected to the knuckle device 220a.

[0060] The steering device 280a is a rod-shaped device having a fixed end fixed to the main body 300 and a connecting end connected to the knuckle device 220a. The steering device 280a includes a male shaft at the fixed end and a female shaft at the connecting end. The female shaft moves in the axial direction of the steering device 280a (i.e., the direction of arrow M1 or the opposite direction) in response to a control signal from the control device 100 (a control signal for turning the vehicle 1). That is, the steering device 280a is configured to be extendable and retractable in the axial direction of the steering device 280a (i.e., the direction of arrow M1 or the opposite direction) based on the control signal. Note that the telescopic mechanism of the steering device 280a is configured so that the female shaft, having a helical structure, is inserted or removed by rotating it inside the male shaft, which has an inner wall formed to fit into the helical structure. However, any structure that can adjust the amount of extension and retraction in response to a control signal including the angle at which the vehicle 1 is turned may be used. Therefore, the telescopic mechanism may also be configured using a hydraulic or pneumatic cylinder mechanism. In addition to the steering device shown in FIG. 5, various other types of steering devices such as a rack and pinion type and a ball nut type can be used.

[0061] The knuckle unit 220a includes a first arm 225a extending toward the steering unit 280a and a second arm 222a extending toward the connecting rod 210a, with a base connected to the left front driving wheel 250a as its center. The base of the knuckle unit 220a has a left end connected to the left front driving wheel 250a and a right end rotatably connected to the main body 300 via a suspension unit 260a in the left-right direction (i.e., in a direction perpendicular to the forward movement of the vehicle 1). In other words, the left front driving wheel 250a connected to the left end of the knuckle unit 220a rotates in the left-right direction around the right end (connecting portion 221a) rotatably connected to the suspension unit 260a as its rotation axis.

[0062] The first arm 225a includes a base end fixed to the base side and the other end 224 rotatably connected to the connecting end of the steering device 280a. In other words, when the steering device 280a extends or contracts, the force is transmitted to the knuckle device 220a via the other end 224.

[0063] The second arm 222a includes a base end fixed to the base portion and an other end 223a rotatably connected to the end of the connecting rod 210a. Here, as shown in FIG. 2, when the left front driving wheel 250a faces a straight direction without rotating left or right, the other end 223a of the second arm 222a is formed to be located outside (i.e., on the side of the left front driving wheel 250a) of an imaginary straight line extending in the forward direction of the vehicle 1 from the right end (connecting portion 221a) of the base end, which serves as the rotation axis of the left front driving wheel 250a. In other words, the other end 223a of the second arm 222a is located outside the right end of the base end when the vehicle 1 is viewed from above.

[0064] The knuckle unit 220b is configured to be substantially symmetrical to the knuckle unit 220a with respect to the central axis of the main body 300. That is, the knuckle unit 220b includes a first arm 225b and a second arm 222b extending toward the connecting rod 210a, with a base connected to the right front driving wheel 250b as the center. The base of the knuckle unit 220b has a right end connected to the right front driving wheel 250b and a left end rotatably connected to the main body 300 via a suspension unit 260b in the left-right direction (i.e., in a direction perpendicular to the forward movement of the vehicle 1). That is, the right front driving wheel 250b connected to the right end of the knuckle unit 220b rotates in the left-right direction around the left end rotatably connected to the suspension unit 260b as the rotation axis (connection unit 221b).

[0065] The first arm 225b includes a base end fixed to the base and an open end that is not connected to anything. The second arm 222a includes a base end fixed to the base and an other end 223b rotatably connected to the end of the connecting rod 210a. As shown in FIG. 2 , when the right front driving wheel 250b is facing a straight direction without rotating left or right, the other end 223b of the second arm 222b is formed to be located outside (i.e., on the side of the right front driving wheel 250b) of an imaginary straight line that extends in the forward direction of the vehicle 1 from the left end of the base end, which serves as the rotation axis (connecting portion 221b) of the right front driving wheel 250b. In other words, when the vehicle 1 is viewed from above, the other end 223b of the second arm 222b is located outside the left end of the base end.

[0066] The connecting rod 210a is a rod-shaped member having one end (left end) rotatably connected to the other end 223a of the knuckle gear 220a and the other end (right end) opposite to the one end rotatably connected to the other end 223b of the knuckle gear 220b. The left and right knuckle gears 220a and 220b are connected by the connecting rod 210a, which enables the left front drive wheel 250a and the right front drive wheel 250b to rotate left and right in conjunction with each other.

[0067] That is, for example, in FIG. 5 , when a control signal for turning the vehicle 1 right is generated in the control device 100, the steering device 280a extends in the direction of arrow M1 along its axial direction by a predetermined amount based on the control signal. Then, the knuckle device 220a, which is rotatably connected to the connecting end of the steering device 280a, rotates together with the left front driving wheel 250a in the direction of arrow M2 as a whole. Furthermore, in conjunction with this rotation, the connecting rod 210a, which is connected to the other end 223a of the second arm of the knuckle device 220a, moves in the direction of arrow M3 as a whole. Then, the knuckle device 220b, which is connected to the other end (right end) of the connecting rod 210a, rotates together with the right front driving wheel 250b in the direction of arrow M4 as a whole. This allows the left front driving wheel 250a and the right front driving wheel 250b to rotate rightward in unison with each other.

[0068] 5, when a control signal for turning the vehicle 1 left is generated in the control device 100, the steering device 280a contracts along its axial direction by a predetermined amount in the direction opposite to the arrow M1 based on the control signal. Then, the knuckle device 220a, which is rotatably connected to the connecting end of the steering device 280a, rotates together with the left front driving wheel 250a in the direction opposite to the arrow M2. Accompanying this rotation, the connecting rod 210a, which is connected to the other end 223a of the second arm of the knuckle device 220a, moves in the direction opposite to the arrow M3. Then, the knuckle device 220b, which is connected to the other end (right end) of the connecting rod 210a, rotates together with the right front driving wheel 250b in the direction opposite to the arrow M4. This allows the left front driving wheel 250a and the right front driving wheel 250b to rotate leftward in unison with each other.

[0069] Here, the length of the connecting rod 210a in the longitudinal direction is longer than the length of a straight line connecting the right end (connecting portion 221a) of the base of the knuckle gear 220a, which serves as the rotational axis of the left front driving wheel 250a, and the left end (connecting portion 221b) of the base of the knuckle gear 220b, which serves as the rotational axis of the right front driving wheel 250b. In other words, a quadrangle is formed by four points: the left end of the connecting rod 210a, the right front end of the connecting rod 210b, the right end of the base of the knuckle gear 220a (connecting portion 221a: position that serves as the rotational axis of the left front driving wheel 250a), and the left end of the base of the knuckle gear 220b (connecting portion 221b: position that serves as the rotational axis of the right front driving wheel 250b). Specifically, when the left front drive wheel 250a and the right front drive wheel 250b are facing in a straight line without rotating left or right, the rectangle forms a trapezoid with the long side connecting the left end of the connecting rod 210a and the right front end of the connecting rod 210b and the short side connecting the right end of the base of the knuckle device 220a and the left end of the base of the knuckle device 220b. This enables the vehicle 1 to turn more smoothly.

[0070] 6A is an explanatory diagram illustrating a simplified turning state of a vehicle 1 according to an embodiment of the present disclosure. Specifically, the diagram illustrates the angles of the left front drive wheel 250a and the right front drive wheel 250b when the vehicle 1 turns right. According to FIG. 6A , when the vehicle 1 turns right at a certain angle, the left front drive wheel 250a rotates rightward around a circle G1, with the right end (connection portion 221a) of the base of the knuckle device 220a as the rotation axis. The circle G1 is centered at an arbitrary position C1 within the turning circle of the vehicle 1, which is on an extension of the rotation axes of the left rear drive wheel 250c and the right rear drive wheel 250d, and has a radius that is a line connecting the position C1 and the left front drive wheel 250a. The right front drive wheel 250b rotates rightward around the left end of the base of the knuckle device 220b as a rotation axis (connection portion 221b) along a circle G2. The circle G2 is centered at position C1, which is the same position as the center of circle G1, and has a radius equal to the line connecting position C1 and the right front drive wheel 250b.

[0071] 6A, when the vehicle 1 is turned to the right, the rotation angle R2 of the right front driving wheel 250b (i.e., the angle formed by the right front driving wheel 250b rotating to the right relative to the right front driving wheel 250b when traveling straight) which is the inner wheel is larger than the rotation angle R1 of the left front driving wheel 250a (i.e., the angle formed by the left front driving wheel 250a rotating to the right relative to the left front driving wheel 250a when traveling straight). This enables the vehicle 1 to turn more smoothly, especially when traveling at low speeds.

[0072] 6A has been described for the case where the vehicle 1 is turned to the right, but when turning to the left, the mechanism is the same as when turning to the right, except that the center of the circle is located on the left side of the vehicle 1 and the magnitude of the rotation angle of each drive wheel is reversed. Also, the centers (position C1) of the circles G1 and G2 of each drive wheel may be configured to move on extensions of the rotation axes of the left rear drive wheel 250c and the right rear drive wheel 250d according to the turning angle of the vehicle 1 set by the control signal.

[0073] Returning to FIG. 5 , when the left front drive wheel 250a and the right front drive wheel 250b are facing straight ahead without rotating left or right, the rectangle formed by the connecting rod 210a and the like is a trapezoid with the long side connecting the left end of the connecting rod 210a to the right front end of the connecting rod 210b and the short side connecting the right end of the base of the knuckle gear 220a to the left end of the base of the knuckle gear 220b. This allows the rotation angle of the drive wheel on the inside of the turn to be larger than the rotation angle of the drive wheel on the outside of the turn, as shown in FIG. 6A . This allows the vehicle 1 to turn more smoothly, especially when turning at low speeds.

[0074] 5, the length of the connecting rod 210a is adjusted so that the connecting rod 210a forms a trapezoid with the long side connecting the left end of the connecting rod 210a and the right front end of the connecting rod 210b and the short side connecting the right end of the base of the knuckle gear 220a and the left end of the base of the knuckle gear 220b. However, this is not limiting, and the length of the connecting rod 210a can also be adjusted so that the connecting rod 210a forms a trapezoid with the short side connecting the left end of the connecting rod 210a and the right front end of the connecting rod 210b and the long side connecting the right end of the base of the knuckle gear 220a and the left end of the base of the knuckle gear 220b. In this case, the connecting rod 210a is positioned inside the side connecting the right end of the base of the knuckle gear 220a and the left end of the base of the knuckle gear 220b (i.e., toward the rear drive gear 200b of the vehicle 1).

[0075] 5 has been used to describe the operation of the front drive unit 200a, but the rear drive unit 200b can also be rotated in a direction perpendicular to the forward movement of the vehicle 1. In this case, when a control signal for controlling the rotation of the front drive unit 200a is received, the rear drive unit 200b is also rotated in the same manner. That is, like the front drive unit, the rear drive unit 200b includes a steering unit 280b configured to be extendable and retractable upon receiving a control signal, a knuckle unit 220c connected to one end of the steering unit 280b, a connecting rod 210b connected to the end of the knuckle unit 220c opposite to the end to which the one end of the steering unit 280b is connected, and a knuckle unit 220c connected to the end of the connecting rod 210a opposite to the end connected to the knuckle unit 220c. Further, the knuckle unit 220c is connected to the left rear drive wheel 250c, and the knuckle unit 220d is connected to the right rear drive wheel 250d. Therefore, as in the operation described in Fig. 5, as the steering unit 280b expands and contracts, the knuckle unit 220c, the connecting rod 210b, and the knuckle unit 220d operate, causing the left rear drive wheel 250c and the right rear drive wheel 250d to rotate in unison. A detailed description of this operation will be omitted as it is the same as that of the front drive unit 200a.

[0076] 6B is an explanatory diagram illustrating a simplified turning state of the vehicle 1 according to an embodiment of the present disclosure. Specifically, the diagram illustrates the angles of the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d when the vehicle 1 turns to the right. That is, while FIG. 6A illustrates a case in which only the left front drive wheel 250a and the right front drive wheel 250b rotate, FIG. 6B illustrates a case in which all four wheels, the left front drive wheel 250a, the right front drive wheel 250b, the left rear drive wheel 250c, and the right rear drive wheel 250d, rotate.

[0077] 6B , when the vehicle 1 is turned rightward at a certain angle, the left front drive wheel 250a and the left rear drive wheel 250c rotate rightward along a circle G3, with the right end of the base of the knuckle gear 220a and the right end of the base of the knuckle gear 220c as their respective rotation axes. The circle G3 is a circle whose center is an arbitrary position C2 within the turning circle of the vehicle 1, on a straight line extending from the center of gravity of the rectangle formed by the drive wheels in a direction perpendicular to the forward direction of the vehicle 1, and whose radius is a line connecting position C2 with the left front drive wheel 250a and the left rear drive wheel 250c. The right front drive wheel 250b and the right rear drive wheel 250d rotate rightward along a circle G4, with the left end of the base of the knuckle gear 220b and the left end of the base of the knuckle gear 220d as their respective rotation axes. The circle G4 has its center at position C2, which is the same position as the center of circle G3, and its radius is a line connecting position C2 with right front drive wheel 250b and right rear drive wheel 250d. Position C2 is preferably located on a line midway between an extension line of the longitudinal rotation axes of left front drive wheel 250a and right front drive wheel 250b and an extension line of the longitudinal rotation axes of left rear drive wheel 250c and right rear drive wheel 250d.

[0078] 6B , when the vehicle 1 is turned to the right, the rotation angle R4 of the right front driving wheel 250b (i.e., the angle formed by the right front driving wheel 250b rotating to the right relative to the right front driving wheel 250b when traveling straight) and the rotation angle R6 of the right rear driving wheel 250d (i.e., the angle formed by the right rear driving wheel 250d rotating to the right relative to the right rear driving wheel 250d when traveling straight) which are the inside wheels are larger than the rotation angle R3 of the left front driving wheel 250a (i.e., the angle formed by the left front driving wheel 250a rotating to the right relative to the left front driving wheel 250a when traveling straight) and the rotation angle R5 of the left rear driving wheel 250c (i.e., the angle formed by the left rear driving wheel 250c rotating to the right relative to the left rear driving wheel 250c when traveling straight). This enables the vehicle 1 to turn more smoothly, especially when traveling at low speeds. Furthermore, by rotating all four drive wheels, the vehicle 1 can be turned in a smaller radius.

[0079] 6B has been described for the case where the vehicle 1 is turned to the right, but for the case where the vehicle 1 is turned to the left, the mechanism is the same as for the case where the vehicle 1 is turned to the right, except that the center of the circle is located on the left side of the vehicle 1 and the rotation angles of the drive wheels are opposite in magnitude. Also, the centers (position C2) of the circles G3 and G4 of the drive wheels may be configured to move on the same straight line according to the turning angle of the vehicle 1 set by the control signal.

[0080] In the example of Fig. 6A, only the front drive unit 200a is rotated, and in the example of Fig. 6B, both the front drive unit 200a and the rear drive unit 200b are rotated. However, it is also possible to rotate only the rear drive unit 200b.

[0081] As shown in Figures 6A and 6B, by rotating each drive wheel along a circle with a common center (circles G1 and G2, or circles G3 and G4), the ground contact force with the ground can be reduced, and handling performance and driving performance can be further improved, especially on uneven terrain.

[0082] 4. Configuration of Wheel Mechanism Fig. 7 is a perspective view showing the configuration of wheel mechanism 250 of vehicle 1 according to one embodiment of the present disclosure. Specifically, Fig. 7 is a diagram showing the configuration of left front wheel mechanism 250 including left front drive wheel 250a of vehicle 1. Note that although the other wheel mechanisms (i.e., right front wheel mechanism 250, left rear wheel mechanism 250, and right rear wheel mechanism 250) are not shown, the other wheel mechanisms also have the same configuration as wheel mechanism 250.

[0083] 7, the left front wheel mechanism 250 includes at least a left front driving wheel 250a, a knuckle unit 220a, and a suspension unit 260a. The configuration of the left front driving wheel 250a is as described in FIGS. 1 and 2. As described in FIG. 5, the knuckle unit 220a includes at least a left end 226a to which the left front driving wheel 250a is connected and a right end (connecting portion 221a) connected to the suspension unit 260a so as to be rotatable in the left-right direction (i.e., in a direction perpendicular to the forward movement of the vehicle 1). That is, the connecting portion 221a of the knuckle unit 220a has an axle center 227a extending along a straight line H1 that serves as the left-right rotation axis of the left front driving wheel 250a, and the knuckle unit 220a is configured to be rotatable around the axle center 227a.

[0084] The knuckle device 220a is made of, for example, a metal material such as aluminum, steel, or an alloy thereof, a resin material such as fiber-reinforced resin or hard urethane, or a combination thereof, preferably steel or an alloy thereof, and more preferably carbon steel or an alloy thereof. The knuckle device 220a is an important component that supports the load of people or objects placed on the vehicle 1, and by making it of carbon steel or an alloy thereof, it is possible to ensure sufficient rigidity.

[0085] The suspension device 260a includes at least a pair of upper and lower connecting arms 268a and 269a configured to sandwich the connecting portion 221a of the knuckle device 220a from above and below, and an elastic mechanism 261a. The connecting arm 268a has one end 263a with a hole centered on a line H1, which serves as the lateral rotation axis of the left front drive wheel 250a. The shaft 227a of the knuckle device 220a is inserted into the one end 263a, thereby rotatably connecting the suspension device 260a to the knuckle device 220a around the shaft 227a. The connecting arm 268a also has a pair of lower connecting portions 262a, located opposite the one end 263a, that are rotatably connected to the main body 300 in the vertical direction (i.e., the direction of gravity). The lower connecting portions 262a have holes formed along the forward movement direction of the vehicle 1. That is, by inserting the shaft core of the main body 300 into the hole, the suspension device 260a is connected to the main body 300 so as to be rotatable in the vertical direction. Furthermore, the connecting arm 268a has a connecting portion to which the lower end of the elastic mechanism 261a is connected at a position between the one end 263a and the pair of lower connecting portions 262a (i.e., a position that is approximately the center of gravity of the connecting arm 268a).

[0086] The connecting arm 269a has one end 264a with a hole centered on a straight line H1, which serves as the lateral rotation axis of the left front drive wheel 250a. An axle 227a of the knuckle device 220a is inserted into the one end 264a, thereby rotatably connecting the suspension device 260a to the knuckle device 220a about the axle 227a. The connecting arm 269a also has a pair of upper connecting portions 265a, located opposite the one end 264a, that are rotatably connected to the main body 300 in the vertical direction (i.e., the direction of gravity). The upper connecting portions 265a have holes formed in the direction of forward movement of the vehicle 1. By inserting the axle of the main body 300 into the holes, the suspension device 260a is rotatably connected to the main body 300 in the vertical direction.

[0087] The elastic mechanism 261a is composed of an elastic member that can expand and contract in the vertical direction (i.e., toward the center of gravity). Various elastic members, such as a coil spring, rubber, a torsion bar, or a spiral spring, can be used. The lower end of the elastic mechanism 261a is coupled to the lower connecting portion 262a of the connecting arm 268a of the suspension device 260a. The upper end of the elastic mechanism 261a is coupled to the main body 300. Therefore, when a load is applied to the main body 300 in the downward direction (the direction of gravity), one end 263a of the connecting arm 268a and one end 264a of the connecting arm 269a attempt to move in opposite directions, but the elastic mechanism 261a acts to mitigate this sudden movement. In other words, the elastic mechanism 261a can mitigate the load in the direction of gravity and the load in the opposite direction, thereby effectively suppressing vibrations and the like in the vehicle 1.

[0088] Fig. 8 is a perspective view showing the configuration of wheel mechanism 250 of vehicle 1 according to one embodiment of the present disclosure. Specifically, Fig. 8 is a diagram showing the configuration of left front drive wheel 250a of left front wheel mechanism 250. Note that while Fig. 8 shows the structure of left front drive wheel 250a, the other drive wheels (right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d) have the same configuration.

[0089] 8, the left front drive wheel 250a includes a tire and a cylindrical metal wheel on which the tire is mounted. An electric motor 290a (e.g., an in-wheel motor) is disposed inside the wheel. A signal line 291a is connected to the electric motor 290a. A control signal from the control device 100 and an electromagnetic force from a battery or the like are supplied via the signal line 291a.

[0090] 8, electric motor 290 has a rotor fixed to the left front drive wheel 250a side and a stator fixed to the main body 300 at a position corresponding to the rotor. The stator is set in an annular shape around the axis of a rotating shaft 292a of electric motor 290a. Furthermore, rotating shaft 292a of electric motor 290a is connected to the rotating shaft of the wheel via members such as bearings.

[0091] As shown in FIG. 8 , the stator's rotating shaft 292a is formed to be the same as the rotating shaft of the left front driving wheel 250a when rotating the left front driving wheel 250a in a direction to move the vehicle 1 forward or backward. That is, the rotating shaft 292a has a shape that protrudes toward the main body 300 along the rotating shaft. The protruding portion of the rotating shaft 292a is formed cylindrically as a whole, but has at least a flattened flat portion 293a. When the rotating shaft 292a configured in this manner is inserted into the knuckle device 220a, the rotating shaft 292a is coupled to the knuckle device 220a so that it does not rotate. Furthermore, by forming the rotating shaft 292a in a cylindrical shape, the flat portion 293a can withstand loads from the direction of gravity or the opposite direction, thereby more firmly supporting the main body 300. Although the flat portion 293a is formed on only one surface in FIG. 8, another flat portion is similarly formed on the opposite side of the flat portion 293a.

[0092] In this way, the rotating shaft 292a of the stator is connected to the knuckle device 220a, etc., and is thereby fixed to the main body 300, etc. so as not to rotate. On the other hand, the rotor is fixed to the wheel, etc., of the left front drive wheel 250a. Therefore, the stator is formed in an annular shape around the rotating shaft 292a, and the rotor rotates along the annular stator. This causes the left front drive wheel 250a, including the wheel to which the rotor is fixed, to rotate.

[0093] FIG. 9 is a perspective view showing a configuration of a knuckle device 220 of a vehicle 1 according to an embodiment of the present disclosure. Also, FIGS. 10A and 10B are perspective views showing a partial configuration of a knuckle device 220 of a vehicle 1 according to an embodiment of the present disclosure. Specifically, FIG. 9 is a view showing a structure of a knuckle device 220a of a left front wheel mechanism 250. Also, FIG. 10A is a view showing a structure of a first knuckle body 230 constituting the knuckle device 220a. Also, FIG. 10B is a view showing a structure of a second knuckle body 240 constituting the knuckle device 220a. Note that although FIGS. 9, 10A, and 10B show the structure of the left front drive wheel 250a, the other drive wheels (right front drive wheel 250b, left rear drive wheel 250c, and right rear drive wheel 250d) have similar configurations.

[0094] Referring to FIG. 9, the knuckle device 220 a includes at least a first knuckle body 230 , a second knuckle body 240 , and a bearing 229 formed by the first knuckle body 230 and the second knuckle body 240 .

[0095] The first knuckle body 230 and the second knuckle body 240 are fixed so as to contact each other on surfaces formed along the direction of gravity. Specifically, the first knuckle body 230 includes a surface 235a that contacts the second knuckle body 240 and a pair of insertion holes 231a and 231b that are formed to cross a surface 235b opposite to surface 235a. The second knuckle body 240 also includes a surface 245a that contacts the first knuckle body 230 and a pair of insertion holes 241a and 241b (not shown in FIG. 9 ) that are formed to cross a surface 245b opposite to surface 245a (not shown in FIG. 9 ). The pair of insertion holes 231a and 231b, and the pair of insertion holes 241a and 241b, are formed on the same axis at positions where insertion holes 231a and 241a correspond to each other, and insertion holes 231b and 241b correspond to each other. Therefore, first knuckle body 230 and second knuckle body 240 are fixed to each other by inserting a fixed core material so as to straddle insertion holes 231a and 241a, and so as to straddle insertion holes 231b and 241b.

[0096] 9 and 10A, first knuckle body 230 includes first recess 232 formed on surface 235a so as to be recessed in a direction perpendicular to the direction in which rotation shaft 292a is inserted. First recess 232 includes a first upper flat portion 233a, at least a portion of whose upper surface is formed flat, a first lower flat portion 233b, at least a portion of whose lower surface is formed flat, and an arc-shaped side portion formed to connect first upper flat portion 233a and first lower flat portion 233b.

[0097] 9 and 10B , second knuckle body 240 includes second recess 242 formed on surface 245a so as to be recessed in a direction perpendicular to the direction in which rotation shaft 292a is inserted. Second recess 242 includes second upper flat portion 243a, at least a portion of whose upper surface is formed flat, second lower flat portion 243b, at least a portion of whose lower surface is formed flat, and an arc-shaped side portion formed to connect second upper flat portion 243a and second lower flat portion 243b.

[0098] When the first knuckle body 230 and the second knuckle body 240 are fixed together so that their surfaces 235a and 245a contact each other, the first recess 232 and the second recess 242, which are configured in corresponding positions, are integrated to form the bearing 229. The first upper flat portion 233a and the second upper flat portion 243a are integrated to form the same plane. The first lower flat portion 233b and the second lower flat portion 243b are integrated to form the same plane. Therefore, the bearing 229 has an inner surface that is hollow as a whole. The inner surface of the bearing 229 also has an upper flat portion formed by the first upper flat portion 233a and the second upper flat portion 243a being integrated together, and a lower flat portion formed by the first lower flat portion 233b and the second lower flat portion 243b being integrated together.

[0099] The rotating shaft 292a is inserted into the bearing 229 so that the upper flat portion 293a of the rotating shaft 292a contacts the upper flat portion formed in this way, and so that the lower flat portion 293a of the rotating shaft 292a contacts the lower flat portion. This makes it possible for the bearing 229 to support the rotating shaft 292a and to distribute and support the force applied in the direction of gravity or the opposite direction at the flat portion, thereby making it possible to configure a stronger structure.

[0100] 10A and 10B, surface 235a of first knuckle body 230 has a pair of mating protrusions (matting protrusion 234a and mating protrusion 234b). Mating protrusions 234a and mating protrusion 234b are configured to protrude outward from surface 235a. Insertion holes 231a and 231b are formed approximately at the centers of mating protrusions 234a and mating protrusion 234b.

[0101] Furthermore, surface 245a of second knuckle body 240 has a pair of mating recesses (mating recess 244a and mating recess 244b). Mating recess 244a and mating recess 244b are configured to be recessed from surface 245a into its interior at positions corresponding to mating protrusions 234a and 234b. Furthermore, insertion holes 241a and 241b (neither of which are shown in FIG. 10B ) are formed approximately at the centers of mating recess 244a and mating recess 244b. Therefore, first knuckle body 230 and second knuckle body 240 are positioned and fixed to each other by mating protrusion 234a with mating recess 244a and mating protrusion 234b with mating recess 244b. Furthermore, by inserting the same fixed core material into both insertion holes 231a and 241a, and the same fixed core material into both insertion holes 231b and 241b, it is possible to more firmly fix the first knuckle body 230 and the second knuckle body 240 together.

[0102] That is, according to Figures 9, 10A and 10B, the knuckle device 220a includes a bearing 229 that is hollow in a direction along a rotation axis 292a of the left front driving wheel 250a that rotates in at least one of a forward direction and a rearward direction, and that is configured to fix the left front driving wheel 250a by inserting the rotation axis 292a, and a rotation axis portion (connecting portion 221a) that is connected to the main body 300 so as to be rotatable about a rotation axis that is perpendicular to the rotation axis 292a, and that is configured to rotate the left front driving wheel 250a in at least one of a left direction and a right direction.

[0103] Bearing 229 has a hollow inner surface formed with flat portions on at least a portion of the upper and lower surfaces. Knuckle device 220a includes a first knuckle body 230 and a second knuckle body 240 fixed to first knuckle body 230 so as to be in contact with the surface of first knuckle body 230 that is formed along the direction of gravity. First knuckle body 229 includes a first recess 232 formed in the surface that contacts second knuckle body 240 so as to be recessed in a direction perpendicular to rotation axis 292a, and second knuckle body 240 includes a second recess 242 formed in the surface that contacts first knuckle body 230 so as to be recessed in a direction perpendicular to rotation axis 292a. Bearing 229 is defined by first recess 232 and second recess 242.

[0104] First knuckle body 230 includes an engaging convex portion (at least one of engaging convex portion 234a and engaging convex portion 234b) formed to protrude from the surface that contacts second knuckle body 240, and second knuckle body 240 includes an engaging recess (at least one of engaging recess 244a and engaging recess 244b) formed on the surface that contacts first knuckle body 230 so that the engaging recess fits into it, and first knuckle body 230 and second knuckle body 240 are positioned and fixed to each other by the engaging convex portion and the engaging recess.

[0105] 9, 10A, and 10B, any number of mating recesses, mating protrusions, insertion holes, etc. may be formed. Furthermore, any shape may be adopted, such as reversing the arrangement of the recesses and protrusions, or forming the protrusions into a triangular pyramid.

[0106] 9, 10A, and 10B, the bearing 229 is generally hollow and has flat portions on the upper and lower sides of its inner surface to fix the rotating shaft 292a so that it does not rotate. However, the present invention is not limited to this, and the rotating shaft 292a and the bearing 229 may have any shape, such as by forming the rotating shaft 292a in a threaded shape and forming the bearing 229 in a threaded hole shape.

[0107] 11 is a perspective view showing the configuration of a main body 300 of a vehicle 1 according to an embodiment of the present disclosure. The main body 300 includes a main body chassis 310 configured so that its longitudinal direction corresponds to the forward movement of the vehicle 1, and a mounting base 360 ​​installed on the main body chassis 310 so as to be slidable in the longitudinal direction of the main body chassis 310. The main body chassis 310 has a left front region 320a on the left front side to which the left front wheel mechanism 250 is connected, a right front region 320b on the right front side to which the right front wheel mechanism 250 is connected, a left rear region 320c on the left rear side to which the left rear wheel mechanism 250 is connected, and a right rear region 320d on the right rear side to which the right rear wheel mechanism 250 is connected.

[0108] The left front region 320a includes a lower shaft portion 311a for rotatably connecting the lower connecting portion 262a of the suspension device 260a in the direction of gravity or the opposite direction, an upper shaft portion 312a for rotatably connecting the upper connecting portion 265a of the suspension device 260a in the direction of gravity or the opposite direction, and a connecting portion 313a to which the upper end of the elastic mechanism 261a of the suspension device 260a is connected. The lower shaft portion 311a, the upper shaft portion 312a, and the connecting portion 313a each have an axis that serves as a rotation axis when the connected parts of the suspension device 260a rotate. In other words, the axis of the lower shaft portion 311a is inserted into a hole in the lower connecting portion 262a of the suspension device 260a, thereby rotatably connecting the lower connecting portion 262a of the suspension device 260a to the main body 300. Furthermore, the shaft core of upper shaft portion 312a is inserted into a hole in upper connecting portion 265a of suspension device 260a, thereby rotatably connecting upper connecting portion 265a of suspension device 260a to main body 300. Furthermore, the shaft core of coupling portion 313a is inserted into a hole in elastic mechanism 261a of suspension device 260a, thereby rotatably connecting the upper end portion of elastic mechanism 261a of suspension device 260a to main body 300.

[0109] The right front region 320b, the left rear region 320c, and the right rear region 320d each have the same configuration as the left front region 320a, and rotatably connect the suspension devices 260b to 260d, respectively, but the details are omitted as they are similar.

[0110] The mounting base 360 ​​has a horizontally elongated plate-like structure extending along the short side of the main chassis 310. The mounting base 360 ​​has slide rails 361 on its underside along the short side of the main chassis 310. The slide rails 361 are formed in pairs along the longitudinal sides of the mounting base 360. At least a portion of any accessory device is slidably connected to the slide rails 361. In other words, the accessory device can be installed from the side of the vehicle 1 by sliding along the slide rails 361. Examples of accessories that can be installed on the underside of the mounting base 360 ​​via the slide rails 361 include a cultivator, a lawnmower, and a seed sower.

[0111] 11, the attachment device is attached to the underside of the mounting base 360 ​​by using slide rails 361, but it is of course possible to attach the attachment device by other methods such as screw fastening. Also, in FIG. 11, the slide rails 361 are provided so as to slide from the side of the vehicle 1, but they may be provided so as to slide from the front or rear of the vehicle 1.

[0112] The mounting table 360 ​​has a mounting surface 362 on its upper surface, and a carrier table or any accessory device can also be placed on the mounting surface 362. The mounting surface 362 includes screw holes 363a to 363d for fastening the carrier table or any accessory device to be placed thereon.

[0113] Here, FIG. 12 is a side view showing a state in which the platform 900 is connected to the vehicle 1 according to an embodiment of the present disclosure. Also, FIG. 13 is a perspective view showing a configuration of the platform 900 connected to the vehicle 1 according to an embodiment of the present disclosure. Specifically, FIG. 12 is a view showing a state in which the platform 900 shown in FIG. 13 is placed on the upper mounting surface 362 of the mounting base 360 ​​shown in FIG. 11. According to FIG. 12, the platform 900 is placed on the upper surface of the mounting base 360 ​​and is configured so that items such as animals including people and agricultural products can be placed inside the platform. In this way, by installing the platform 900 on the main body 300, the vehicle 1 can be effectively used as a transport vehicle or a transport robot.

[0114] 13, the carrier 900 has a structure in which the bottom, front, rear, left and right sides are covered with wall members, making it possible to store animals, items and the like inside the carrier through the open top side.

[0115] 11 , by placing such a carrier 900 on the mounting surface 362, the vehicle 1 can be used effectively. Note that, instead of the carrier 900, any accessory device can be fixed to the mounting surface 362. Examples of such accessory devices include a pesticide sprayer, a watering machine, and various other devices.

[0116] 11, the carrier 900 and the accessory devices are fixed to the mounting surface 362 by inserting screws into the screw holes 363a to 363d. However, this is not limiting, and any method of fixing is possible, such as using a slide rail or screws.

[0117] Although not shown in FIG. 11, the control device 100 and the sensor 600 are installed at either the mounting base 360 ​​of the main body 300 or the main body chassis 310 .

[0118] As described above, in this embodiment, it is possible to provide a vehicle and a drive device thereof that have superior driving performance.

[0119] 1 to 13, in both the front drive unit 200a and the rear drive unit 200b of the vehicle 1, electric motors are provided corresponding to each drive wheel so as to rotate in the forward or reverse direction of the vehicle 1. However, it is sufficient if a pair of electric motors is provided in either the front drive unit 200a or the rear drive unit 200b. In other words, it is possible for a pair of drive wheels of the front drive unit 200a of the vehicle 1 to be provided with corresponding electric motors, and for the wheels of the rear drive unit 200b to be provided as simple rotating wheels, or vice versa.

[0120] 1 to 13, the vehicle 1 is configured to rotate left and right in both the front drive unit 200a and the rear drive unit 200b. However, it is sufficient that either the front drive unit 200a or the rear drive unit 200b rotates left and right, and it is not necessary that both rotate.

[0121] 1 to 13 show various pairs of structures, such as a hole and an axis, or a recess and a protrusion, but these do not have to be used in the combinations shown in Figures 1 to 13. For example, although mating protrusion 234a is provided on surface 235a and mating recess 244a is provided on surface 245a, the mating protrusion may be provided on surface 245a and the mating recess may be provided on surface 235a.

[0122] 1 to 13, the vehicle 1 is described as a four-wheeled vehicle, but it may be a two-wheeled, three-wheeled, or five-wheeled or more. Also, in the description of Figures 1 to 13, the vehicle 1 is described as carrying a platform or the like, but it may also be a vehicle that tows a platform or the like.

[0123] The processes and procedures described herein can be realized not only by those explicitly described in the embodiments, but also by software, hardware, or a combination thereof. Specifically, the processes and procedures described herein can be realized by implementing logic corresponding to the processes in a medium such as an integrated circuit, volatile memory, non-volatile memory, magnetic disk, or optical storage. Furthermore, the processes and procedures described herein can be implemented as computer programs and executed by various computers, including processing devices and server devices.

[0124] Although processes and procedures described herein are described as being performed by a single device, software, component, or module, such processes or procedures may be performed by multiple devices, multiple software, multiple components, and / or multiple modules. Furthermore, although various information described herein is described as being stored in a single memory or storage unit, such information may be stored in multiple memories within a single device or multiple memories distributed across multiple devices. Furthermore, software and hardware elements described herein may be realized by integrating them into fewer components or by decomposing them into more components.

[0125] 1: Vehicle 100: Control device 200: Drive device 200a: Front drive device 200b: Rear drive device 210a: Connecting rod 210b: Connecting rod 220: Knuckle device 220a: Knuckle device 220b: Knuckle device 220c: Knuckle device 220d: Knuckle device 221a: Connecting portion 221b: Connecting portion 221c: Connecting portion 221d: Connecting portion 222a: Second arm 222b: Second arm 223a: Other end portion 223b: Other end portion 224: Other end portion 225a: First arm 225b: First arm 226a: Left end portion 227a: Shaft core 229: Bearing 230 : First knuckle body 231a : Insertion hole 231b : Insertion hole 232 : First recess 233a : First upper flat portion 233b : First lower flat portion 234a : Fitting convex portion 234b : Fitting convex portion 235a : Surface 235b : Surface 240 : Second knuckle body 241a : Insertion hole 241b : Insertion hole 242 : Second recess 243a : Second upper flat portion 243b : Second lower flat portion 244a : Fitting concave portion 244b : Fitting concave portion 245a : Surface 245b : Surface 250 : Wheel mechanism 250a : Left front drive wheel 250b : Right front drive wheel 250c : Left rear drive wheel 250d: Right rear drive wheel 260a: Suspension device 260b: Suspension device 260c: Suspension device 260d: Suspension device 261a: Elastic mechanism 262a: Lower connecting portion 263a: One end portion 264a: One end portion 265a: Upper connecting portion 268a: Connecting arm 269a: Connecting arm 280: Steering device 280a: Steering device 280b: Steering device 290: Electric motor 290a: Electric motor 290b: Electric motor 290c: Electric motor 290d: Electric motor 291a: Signal line 292a: Rotating shaft 293a: Flat portion 300: Main body 310: Main body chassis 311a: Lower shaft portion 312a : Upper shaft portion 313a : Joint portion 320a : Left front region 320b : Right front region 320c : Left rear region 320d : Right rear region 360 : Placement base 361 : Slide rail 362 : Placement surface 363a : Screw hole363d: Screw hole 600: Sensor 800: Accessory device 900: Carrier

Claims

1. A vehicle comprising: a plurality of drive wheels mounted on a body, each configured to rotate in at least one of a leftward direction and a rightward direction; and a plurality of electric motors provided for each corresponding one of the plurality of drive wheels, each configured to generate a drive torque that rotates each corresponding drive wheel in at least one of a forward direction and a backward direction.

2. The vehicle according to claim 1, wherein the plurality of drive wheels include a pair of front drive wheels located in front of the body and a pair of rear drive wheels located in rear of the body.

3. The vehicle according to claim 2, wherein the pair of front drive wheels are connected to each other via a connecting rod and are configured to rotate in conjunction with each other in at least one of the left and right directions.

4. A vehicle as described in claim 3, wherein the pair of rear drive wheels are connected to each other via a connecting rod and are configured to rotate in conjunction with each other in at least one of the left and right directions, and to rotate in conjunction with the pair of front drive wheels in at least one of the left and right directions.

5. A vehicle as described in claim 3, wherein the pair of rear drive wheels are connected to each other via a connecting rod and are configured to rotate in conjunction with each other in at least one of the left and right directions, and to rotate in at least one of the left and right directions independently of the pair of front drive wheels.

6. A vehicle as set forth in claim 2, wherein the pair of front drive wheels includes a left front drive wheel and a right front drive wheel, and the left front drive wheel and the right front drive wheel are configured to rotate in at least one of the left direction and the right direction along circles having the same center.

7. A vehicle as set forth in claim 2, wherein the pair of front drive wheels includes a left front drive wheel and a right front drive wheel, the pair of rear drive wheels includes a left rear drive wheel and a right rear drive wheel, and the left front drive wheel, the right front drive wheel, the left rear drive wheel and the right rear drive wheel are configured to rotate in at least one of the left direction and the right direction along circles each having a center at the same position.

8. A vehicle as described in claim 1, wherein the plurality of drive wheels are configured so that their rotation in at least one of the left and right directions, or at least one of the forward and backward directions, is controlled based on control information from a control device installed on the main body.

9. The vehicle according to claim 8, wherein each of the plurality of drive wheels is configured to rotate in at least one of the forward direction and the rearward direction independently of one another based on the control information.

10. A vehicle as described in claim 1, wherein the main body includes a sensor for detecting external environmental information around the main body, and each of the plurality of drive wheels is configured such that rotation in at least one of the left and right directions, or rotation in at least one of the forward and backward directions, is controlled based on the external environmental information detected by the sensor.

11. The vehicle of claim 1, wherein each of said plurality of drive wheels is coupled to a corresponding suspension device.

12. The vehicle of claim 1, wherein the main body is connectable to a carrier on which an animal or an object can be placed.

13. A vehicle according to claim 1 for transporting agricultural produce harvested on agricultural land.

14. A drive device comprising: a plurality of drive wheels, each configured to rotate in at least one of a left direction and a right direction; and a plurality of electric motors provided for each corresponding one of the plurality of drive wheels, configured to generate drive torque that rotates each corresponding drive wheel in at least one of a forward direction and a backward direction.

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