Cargo handling moving body, method for operating cargo handling moving body, and method for controlling cargo handling moving body

Abstract

A cargo handling moving body (10) includes: a left and right pair of drive wheels (31, 32); a vehicle body (11) configured to swing about an axis coaxial with an axle of the left and right pair of drive wheels (31, 32); a cargo handling device (40) supported by the vehicle body (11); an assisting member (61) provided with a leg part (64) including a contact part that comes into contact with a travel surface (F); an attitude control unit (51) configured to control the attitude of the vehicle body (11); a support member control unit configured to control a movement device so as to position a support member at a cargo handling position or a retracted position; and a mode control unit configured to set a mode of the assisting member (61) with respect to the travel surface (F) to either an assisting mode or a non-assisting mode.

Description

Load-carrying mobile body, operating method of load-carrying mobile body, and control method of load-carrying mobile body

[0001] The present disclosure relates to a load-carrying mobile body, an operating method of the load-carrying mobile body, and a control method of the load-carrying mobile body.

[0002] For example, Patent Document 1 discloses a load-carrying mobile body. The load-carrying mobile body disclosed in Patent Document 1 is of an inverted wheel type. The load-carrying mobile body includes a pair of left and right drive wheels, a vehicle body swingable about an axis coaxial with the axles of the pair of left and right drive wheels as a swing center, and a load-carrying device supported by the vehicle body. Further, the vehicle body includes a drive unit for driving the pair of left and right drive wheels and a control device for controlling the drive unit. The control device includes an attitude control unit. The attitude control unit controls the drive of the pair of left and right drive units to swing the vehicle body and control the attitude of the vehicle body. Specifically, the attitude control unit tilts the vehicle body to move the center of gravity of the load-carrying mobile body in the front-rear direction in order to invert the load-carrying mobile body. At this time, the load-carrying mobile body utilizes the weight of the vehicle body itself as a balance weight to enable the inversion of the load-carrying mobile body.

[0003] Japanese Patent Application Laid-Open No. 2024-88228

[0004] In the load-carrying mobile body disclosed in Patent Document 1, when inverting or traveling with a load supported by a support member of the load-carrying device, the farther the position of the load supported by the support member is from the vehicle body, the greater the weight of the vehicle body required for inverting or traveling becomes. Also, the greater the weight of the load carried by the load-carrying device, the more unstable the load carrying by the load-carrying mobile body becomes.

[0005] According to one aspect of the present disclosure, an inverted wheel type cargo handling mobile is provided. The cargo handling mobile comprises a vehicle body comprising a pair of left and right drive wheels and a drive unit configured to drive the pair of left and right drive wheels, and configured to pivot on an axis coaxial with the axles of the pair of left and right drive wheels by the drive of the drive unit; a cargo handling device supported by the vehicle body, wherein the cargo handling device comprises a support member for supporting a load and a moving device configured to move the support member, wherein the support member is configured to be displaced between a cargo handling position in which the load is handled by the moving device and a retracted position in the front-rear direction that is closer to the vehicle body than the cargo handling position; and an auxiliary member comprising a leg portion including a contact portion that contacts the running surface on which the cargo handling mobile travels, wherein the leg portion is connected to the vehicle body and the running surface The auxiliary member is configured to support the vehicle body by bringing the contact portion into contact with the surface, and the auxiliary member is provided in the front-rear direction on the side opposite to the side on which loading and unloading is performed by the support member relative to the vehicle body; an attitude control unit configured to control the attitude of the vehicle body by swinging the vehicle body with the axis as the pivot point; a support member control unit configured to control the moving device so as to position the support member at the loading / unloading position or the retraction position; and an attitude control unit configured to set the orientation of the auxiliary member relative to the running surface to either an auxiliary orientation in which the contact portion is in contact with the running surface and the vehicle body is supported by the leg portion, or a non-auxiliary orientation in which the contact portion is not in contact with the running surface.

[0006] According to another aspect of this disclosure, a method for operating an inverted wheel type cargo handling mobile body is provided. The cargo handling mobile body comprises a pair of left and right drive wheels and a drive unit configured to drive the pair of left and right drive wheels, and a vehicle body configured to pivot around an axis coaxial with the axles of the pair of left and right drive wheels by the drive unit; and a cargo handling device supported by the vehicle body, the cargo handling device comprising a support member for supporting a load and a moving device configured to move the support member, the support member configured to be displaced between a cargo handling position in which the load is handled by the moving device and a retracted position in the front-rear direction that is closer to the vehicle body than the cargo handling position; and an auxiliary member comprising a leg portion including a contact portion that contacts the running surface on which the cargo handling mobile body travels, and a displacement device configured to change the position of the leg portion relative to the vehicle body, the leg portion being connected to the vehicle body and configured to support the vehicle body by contacting the contact portion with the running surface, and the auxiliary member being provided in the front-rear direction on the side opposite to the side on which cargo handling is performed by the support member relative to the vehicle body, and the axle The cargo handling device comprises: an attitude control unit configured to control the attitude of the vehicle body by oscillating the vehicle body around a line as the pivot point; a support member control unit configured to control the moving device to position the support member at the loading / unloading position or the retraction position; and an attitude control unit configured to control the displacement device to change the configuration of the auxiliary member with respect to the running surface to either an auxiliary configuration in which the contact portion is in contact with the running surface and the leg portion supports the vehicle body, or a non-auxiliary configuration in which the contact portion is not in contact with the running surface; wherein during loading / unloading by the cargo handling device, the support member control unit is configured to move the support member supporting the load from the loading / unloading position to the retraction position; the attitude control unit is configured to tilt the vehicle body in the front-rear direction to the side opposite to the side on which loading / unloading is performed by the support member; and the attitude control unit is configured to control the displacement device to change the position of the leg portion in a direction in which the contact portion is in contact with the running surface in order to change the configuration of the auxiliary member to the auxiliary configuration.When the cargo handling mobile body is traveling with the load supported by the support member in the retracted position, the attitude control unit is configured to tilt the vehicle body in the direction of travel of the cargo handling mobile body, and the configuration control unit is configured to control the displacement device to change the position of the leg portion in a direction that separates the contact portion from the travel surface in order to change the configuration of the auxiliary member to the non-auxiliary configuration.

[0007] According to these findings, when the cargo handling vehicle is in motion, the support member is in the retracted position. For example, compared to when the cargo handling vehicle is in motion with the support member in the cargo handling position, the weight of the vehicle body used as a balance weight to invert the vehicle body can be reduced. Before the cargo handling vehicle is in motion, the support member control unit moves the support member from the cargo handling position to the retracted position. At this time, when the mode control unit changes the mode of the auxiliary member to the auxiliary mode, the contact portion comes into contact with the running surface. As a result, the vehicle body can be supported by the auxiliary member in the auxiliary mode, allowing the cargo handling vehicle to move the support member from the cargo handling position to the retracted position in a stable state.

[0008] Furthermore, during cargo handling of the cargo handling mobile vehicle, the configuration control unit changes the configuration of the auxiliary member relative to the running surface to bring the contact portion into contact with the running surface. This allows for more stable cargo handling compared to when cargo handling is performed by inverting the vehicle body using only the left and right drive wheels. As a result, the cargo handling mobile vehicle can perform cargo handling stably and its body weight can be reduced.

[0009] Regarding the cargo handling vehicle, the contact portion is preferably an auxiliary wheel that rotates in contact with the running surface. This allows the cargo handling vehicle to run smoothly.

[0010] With respect to a cargo handling mobile body, the auxiliary member further comprises a displacement device configured to change the position of the leg portion relative to the vehicle body, and the cargo handling mobile body further comprises an auxiliary member control unit configured to control the displacement device to change the configuration of the auxiliary member to either the auxiliary configuration or the non-auxiliary configuration, and the configuration control unit may be the auxiliary member control unit.

[0011] According to this, the auxiliary member control unit changes the position of the leg relative to the vehicle body, causing the contact portion to move toward and away from the running surface. This makes it possible to move the contact portion toward and away from the running surface without significantly tilting the vehicle body.

[0012] With respect to the cargo handling mobile body, the legs and contact parts are provided on the vehicle body with their relative positions to the vehicle body fixed, and the configuration control unit includes the attitude control unit, which is configured to swing the legs and contact parts by swinging the vehicle body, thereby changing the configuration of the auxiliary member to either the auxiliary configuration or the non-auxiliary configuration.

[0013] According to this, the structure of the auxiliary member can be simplified. With respect to the cargo handling mobile body, it is preferable that the mode control unit be configured to change the mode of the auxiliary member to the auxiliary mode when the cargo handling mobile body is in motion.

[0014] According to this, the cargo handling vehicle can travel stably because, in addition to the pair of drive wheels on the left and right, auxiliary wheels can also be in contact with the running surface. With respect to the cargo handling vehicle, the auxiliary members are provided on the front and rear sides of the vehicle body, and the support members support the load either in front of or behind the vehicle body.

[0015] According to this, loading and unloading can be performed on the front or rear side of the vehicle body, and the vehicle body can be supported by auxiliary members during each loading and unloading operation. Regarding the operation method of the loading and unloading mobile body, before the loading and unloading mobile body travels with the load supported by the support member in the retracted position, the attitude control unit is configured to tilt the vehicle body in a direction that straightens the vehicle body which is tilted to the opposite side from the side on which the loading and unloading was performed, and in synchronization with the tilting of the vehicle body by the attitude control unit, the attitude control unit is configured to control the displacement device and change the position of the legs in a direction that straightens the vehicle body by the legs.

[0016] According to this, the attitude control unit can assist in the uprighting motion of the vehicle body by changing the position of the legs relative to the vehicle body. Therefore, the driving force of the drive unit can be reduced compared to when the vehicle body is upright solely by the motion controlled by the attitude control unit.

[0017] Regarding the operation method of the cargo handling mobile body, it is preferable that, when cargo handling is performed by the cargo handling device, the mode control unit controls the displacement device to change the position of the legs in synchronization with the change of the support member supporting the load from the cargo handling position to the retraction position, so as to raise the vehicle body toward the side where the cargo handling was performed.

[0018] According to this, for example, compared to the case where the support member is moved from the loading / unloading position to the retraction position, and then the position of the legs is changed by the behavior control unit to raise the vehicle body toward the side where the loading / unloading took place, the driving force of the displacement device can be reduced.

[0019] Regarding the method of operating the cargo handling mobile body, it is preferable that, when the cargo handling mobile body is at a position further from the load than the position where the cargo handling is performed, the configuration control unit controls the displacement device to change the position of the legs relative to the vehicle body in order to change the configuration of the auxiliary member to the auxiliary configuration, thereby bringing the contact portion into contact with the running surface.

[0020] According to this, when the cargo handling vehicle moves away from the cargo handling position, or when the cargo handling vehicle approaches the cargo handling position, the cargo handling vehicle can make contact with the running surface with its contact points in addition to its pair of drive wheels. Therefore, the cargo handling vehicle can travel in a stable state whether it is approaching or moving away from the cargo handling position.

[0021] Regarding the operation method of the cargo handling mobile body, when the cargo handling mobile body is traveling with the load supported by the support member in the retracted position, the distance by which the mode control unit controls the displacement device to separate the contact portion from the travel surface is preferably such that when the vehicle body tilts due to the stopping of the rotation of the drive wheels, the contact portion contacts the travel surface to prevent the vehicle body from tipping over.

[0022] According to this, when a cargo handling vehicle is in motion, if the vehicle body tilts due to the stopping of rotation of the drive wheels, the contact portion can contact the running surface to prevent the vehicle body from tipping over. A further aspect of this disclosure provides a control method for an inverted wheel type cargo handling vehicle. The cargo handling mobile body comprises a vehicle body comprising a pair of left and right drive wheels and a drive unit configured to drive the pair of left and right drive wheels, and configured to pivot on an axis coaxial with the axles of the pair of left and right drive wheels by the drive unit; a cargo handling device supported by the vehicle body, the cargo handling device comprising a support member for supporting a load and a moving device configured to move the support member, the support member configured to be displaced between a cargo handling position in which the load is handled by the moving device and a retracted position in the front-rear direction that is closer to the vehicle body than the cargo handling position; and an auxiliary member comprising a leg portion including a contact portion that contacts the running surface on which the cargo handling mobile body travels, and a displacement device configured to change the position of the leg portion relative to the vehicle body, the leg portion being connected to the vehicle body and configured to support the vehicle body by contacting the contact portion with the running surface, and the auxiliary member being provided in the front-rear direction on the side opposite to the side on which cargo handling is performed by the support member relative to the vehicle body. The configuration of the auxiliary member with respect to the running surface includes an auxiliary configuration in which the contact portion is in contact with the running surface and the leg portion supports the vehicle body, and a non-auxiliary configuration in which the contact portion is not in contact with the running surface.The control method includes: positioning the support member supporting the load from the loading position to the retraction position when the load handling device is performing load handling; tilting the vehicle body in the front-rear direction toward the side opposite to the side on which load handling is performed by the support member; controlling the displacement device to change the position of the leg portion in a direction that brings the contact portion into contact with the running surface in order to change the configuration of the auxiliary member to the auxiliary configuration; tilting the vehicle body toward the direction of travel of the load handling mobile body when the load is supported by the support member in the retraction position; and controlling the displacement device to change the position of the leg portion in a direction that moves the contact portion away from the running surface in order to change the configuration of the auxiliary member to the non-auxiliary configuration.

[0023] According to this, the cargo handling vehicle can perform cargo handling stably and also reduce the weight of the vehicle itself.

[0024] This invention allows for stable cargo handling and also reduces the weight of the vehicle body.

[0025] Figure 1 is a perspective view showing a cargo handling mobile body of the first embodiment. Figure 2 is a diagram showing the cargo handling mobile body of Figure 1. Figure 3 is a side view showing a loading platform, a pallet, and the cargo handling mobile body of Figure 1. Figure 4 is a block diagram showing the control device for the cargo handling mobile body of Figure 1. Figure 5 is a side view showing the cargo handling mobile body of Figure 1 approaching the loading platform. Figure 6 is a side view showing the cargo handling mobile body of Figure 1 in a rearward-tilting position. Figure 7 is a side view showing the cargo handling mobile body of Figure 1 with the forks inserted into the pallet holes. Figure 8 is a side view showing the cargo handling mobile body of Figure 1 with the forks in the retracted position. Figure 9 is a side view showing the cargo handling mobile body of Figure 1 with the auxiliary wheels separated from the running surface. Figure 10 is a diagram showing a cargo handling mobile body of the second embodiment. Figure 11 is a side view showing the cargo handling mobile body of Figure 10 with the forks in the cargo handling position. Figure 12 is a side view showing the cargo handling mobile body of Figure 10 when the forks are in the retracted position. Figure 13 is a perspective view showing the cargo handling mobile body of a third embodiment. Figure 14 is a side view showing the cargo handling mobile body of Figure 13. Figure 15 is a flowchart showing the operation of the cargo handling mobile body of Figure 13. Figure 16 is a side view showing the cargo handling mobile body of Figure 13 with the auxiliary member in an auxiliary configuration. Figure 17 is a side view showing a modified cargo handling mobile body. Figure 18 is a side view showing another modified cargo handling mobile body.

[0026] (First Embodiment) The following describes a first embodiment that embodies a cargo handling mobile body, a method for operating the cargo handling mobile body, and a method for controlling the cargo handling mobile body.

[0027] <Overall view of the cargo handling mobile vehicle> As shown in Figures 1 and 2, the cargo handling mobile vehicle 10 is of the inverted wheel type. The cargo handling mobile vehicle 10 comprises a vehicle body 11, a right drive wheel 31, a left drive wheel 32, a cargo handling device 40, and an auxiliary member 61. In the following description, front, rear, left, right, up, and down refer to the front, rear, left, right, up, and down relative to the cargo handling mobile vehicle 10. The front-rear direction X is the direction of travel of the cargo handling mobile vehicle 10. The left-right direction Y is the vehicle width direction of the cargo handling mobile vehicle 10. The up-down direction Z is the height direction of the cargo handling mobile vehicle 10. Note that, as shown in Figure 2, left and right are defined when viewing the vehicle body 11 from the front 11a.

[0028] <Vehicle Body> The vehicle body 11 comprises a machine base 12, a battery 33, a housing 35, a right-wheel drive unit 21, a left-wheel drive unit 25, and a control device 50.

[0029] The machine base 12 is plate-shaped. The machine base 12 has a first main surface 121 and a second main surface 122. The first main surface 121 and the second main surface 122 are opposite to each other in the thickness direction of the machine base 12. The thickness direction is the direction from one of the first main surface 121 and the second main surface 122 of the machine base 12 to the other. The battery 33 and the control device 50 are each located on the second main surface 122. The battery 33 is the power source for the cargo handling mobile body 10. The battery 33 may be a primary battery or a secondary battery, as long as it is dischargeable. The control device 50 controls the driving of the cargo handling mobile body 10. The control device 50 will be described later.

[0030] The housing 35 is positioned on the second main surface 122. The housing 35 is box-shaped. The housing 35 comprises a base 35a and four side walls 35b that extend cylindrically from the base 35a toward the machine base 12. The base 35a is the top plate of the housing 35. The upper surface of the base 35a is the mounting surface 351 for the cargo handling device 40. Inside the housing 35, a space is formed defined by the base 35a and the four side walls 35b. The space enclosed by the second main surface 122 of the machine base 12 and the inner surface of the housing 35 is the storage space S. The battery 33 and the control device 50 are housed in the storage space S.

[0031] The right-wheel drive unit 21 is installed on the first main surface 121 of the machine base 12. The right-wheel drive unit 21 comprises a right-wheel drive motor 22, a right axle 23, a right-wheel encoder 24, and a right cover 29a. The right-wheel drive motor 22 and the right-wheel encoder 24 are installed below the first main surface 121. The right-wheel drive motor 22 and the right-wheel encoder 24 are housed inside the right cover 29a. The right axle 23 is connected to the rotation axis of the right-wheel drive motor 22. The right axle 23 rotates when driven by the right-wheel drive motor 22. The right axle 23 penetrates the right cover 29a and protrudes to the outside of the right cover 29a. The right drive wheel 31 is fixed to the protrusion from the right cover 29a on the right axle 23. When the right-wheel drive motor 22 is driven, the right drive wheel 31 is driven via the right axle 23. The right wheel encoder 24 detects the rotation angle, which is the amount of rotation of the right drive wheel 31.

[0032] The left wheel drive unit 25 is installed on the first main surface 121 of the machine base 12. The right wheel drive unit 21 and the left wheel drive unit 25 are installed on the first main surface 121, separated in the left-right direction Y. The left wheel drive unit 25 comprises a left wheel drive motor 27, a left axle 26, a left wheel encoder 28, and a left cover 29b. The left wheel drive motor 27 and the left wheel encoder 28 are installed below the first main surface 121. The left wheel drive motor 27 and the left wheel encoder 28 are housed inside the left cover 29b. The left axle 26 is connected to the rotation axis of the left wheel drive motor 27. The left axle 26 rotates when driven by the left wheel drive motor 27. The left axle 26 penetrates the left cover 29b and protrudes to the outside of the left cover 29b. The left drive wheel 32 is fixed to the part of the left axle 26 that protrudes from the left cover 29b. When the left-wheel drive motor 27 is driven, the left drive wheel 32 is driven via the left axle 26. The left-wheel encoder 28 detects the rotation angle, which is the amount of rotation of the left drive wheel 32.

[0033] <Right drive wheel and left drive wheel> The right drive wheel 31 and the left drive wheel 32 support the vehicle body 11, the cargo handling device 40, and the auxiliary member 61. The right drive wheel 31 is in contact with the running surface F. The left drive wheel 32 is in contact with the running surface F. The running surface F is a horizontal plane. The right drive wheel 31 and the left drive wheel 32 rotate in contact with the running surface F. This causes the cargo handling mobile body 10 to move or travel.

[0034] The right drive wheel 31 and the left drive wheel 32 are a pair of drive wheels provided on the cargo handling mobile body 10. The central axis of the right axle 23 and the central axis of the left axle 26 lie on the same axis L. Therefore, the axles 23 and 26 of the pair of drive wheels 31 and 32 lie coaxially. The vehicle body 11, which includes the machine base 12, the battery 33, the control device 50, the housing 35, the right wheel drive unit 21, and the left wheel drive unit 25, is pivotable around axis L as its pivot point. The right wheel drive unit 21 and the left wheel drive unit 25 are drive units that drive the pair of drive wheels 31 and 32. The right wheel drive unit 21 and the left wheel drive unit 25 are driven by power supplied from the battery 33. Therefore, the battery 33 is the power source for the right wheel drive unit 21 and the left wheel drive unit 25.

[0035] <Auxiliary Member> As shown in Figures 2 and 5, the auxiliary member 61 comprises a leg support portion 63 fixed to the machine base 12, a leg portion 64 supported by the leg support portion 63 so as to be able to move up and down, an auxiliary member motor 66 for raising and lowering the leg portion 64, and an encoder 67. The leg support portion 63 is fixed to the center of the machine base 12 in the left-right direction Y. The leg support portion 63 is cylindrical, and its axis extends in the up-down direction Z.

[0036] The leg portion 64 is inserted into and connected to the leg support portion 63. The leg portion 64 comprises a rod-shaped shaft portion 64a, a wheel support portion 64b connected to the lower end of the shaft portion 64a, and an auxiliary wheel 65 supported by the wheel support portion 64b. The shaft portion 64a has a male screw 641 on its outer surface. The wheel support portion 64b is rotatable about the axis of rotation of the leg portion 64. The wheel support portion 64b rotatably supports the auxiliary wheel 65. The auxiliary wheel 65 rotates in contact with the running surface F.

[0037] As shown in Figure 6, when the vehicle body 11 is tilted to the rear, the auxiliary wheels 65 contact the running surface F, and the legs 64 support the vehicle body 11 via the leg support 63. In this case, the auxiliary member 61 is in auxiliary mode H1, where the auxiliary wheels 65, which are the contact points, are in contact with the running surface F, and the legs 64 support the vehicle body 11. On the other hand, as shown in Figure 5, the auxiliary member 61 can also take a non-auxiliary mode H2, where the auxiliary wheels 65 do not contact the running surface F. The cargo handling mobile body 10 can have the auxiliary member 61 in either auxiliary mode H1 or non-auxiliary mode H2.

[0038] The male screw 641 is connected to the auxiliary member motor 66 via a conversion device (not shown) built into the leg support 63. The rotation of the auxiliary member motor 66 is converted into movement of the shaft 64a in the vertical Z direction via the conversion device (not shown). As a result, the shaft 64a, and thus the leg 64, moves up and down relative to the leg support 63, and the auxiliary wheels 65 also move up and down. Consequently, the position of the leg 64 relative to the vehicle body 11 changes, and the position of the auxiliary wheels 65 also changes. Therefore, the auxiliary member motor 66 is a displacement device for changing the configuration of the auxiliary member 61 to either the auxiliary configuration H1 or the non-auxiliary configuration H2.

[0039] The auxiliary member 61 includes auxiliary wheels 65 that contact the running surface F of the cargo handling mobile body 10 and is connected to the vehicle body 11. The auxiliary member 61 also has legs 64 that support the vehicle body 11 by contacting the auxiliary wheels 65 with the running surface F, and an auxiliary member motor 66 which is a displacement device that changes the position of the legs 64 relative to the vehicle body 11. The encoder 67 detects the rotation angle, which is the amount of rotation of the auxiliary member motor 66.

[0040] <Cargo Handling Device> As shown in Figures 1 and 2, the cargo handling device 40 is mounted on the mounting surface 351 of the base 35a. Therefore, the cargo handling device 40 is supported by the vehicle body 11. The cargo handling device 40 is driven by power supplied from the battery 33.

[0041] The handling device 40 includes a support base 41, a tilt motor 42, a tilt encoder 43, a bar 44, a pair of forks 45 which are support members for supporting the load W, and a pair of fork motors 46 which are moving members for moving these forks 45, and an encoder 47.

[0042] The support base 41 is provided at the center in the front - rear direction X and the left - right direction Y of the installation surface 351 of the pedestal 35a. The tilt motor 42 is supported by the support base 41. The tilt encoder 43 detects the rotation angle as the rotation amount of the tilt motor 42. The bar 44 extends in the left - right direction Y from the tilt motor 42. The first end of the bar 44 is connected to one fork motor 46, and the second end of the bar 44 is connected to the other fork motor 46. The bar 44 extends coaxially with a rotation axis (not shown) of the tilt motor 42. When the rotation axis of the tilt motor 42 rotates by driving the tilt motor 42, the bar 44 rotates, and each fork 45 swings via the pair of fork motors 46 with the bar 44 as the rotation center.

[0043] The rotational position of the fork 45 around the rotation axis of the tilt motor 42 can take a reference position, a tilt - up position, and a tilt - down position by driving the tilt motor 42. The reference position is a position where the upper surface 45a of the fork 45 is parallel to the installation surface 351. Although not shown, the tilt - up position is a position where the tip of the fork 45 is higher than the reference position. The tilt - down position is a position where the tip of the fork 45 is lower than the reference position. Such a change in the position of the fork 45 is executed by driving the tilt motor 42.

[0044] The forks 45 are provided on the upper surface of the fork motor 46. The upper surface 45a of the fork 45 is a flat surface. The forks 45 are in the shape of long plates. The forks 45 include a base end portion and a tip end portion. The tip end portion of the fork 45 is an end portion on the side opposite to the base end portion in the longitudinal direction of the fork 45. The tip end portion of the fork 45 becomes thinner as it goes toward the tip in the longitudinal direction of the fork 45.

[0045] The fork motor 46 moves the fork 45 in the longitudinal direction. The fork motor 46 is a moving device that moves the fork 45. The longitudinal direction of the fork 45 extends in the front-rear direction X of the vehicle body 11. The fork 45 can be moved forward or backward of the vehicle body 11 by driving the fork motor 46. Therefore, the cargo handling device 40 can change the position of the fork 45 in the front-rear direction X of the cargo handling moving body 10.

[0046] When the fork motor 46 rotates in one direction, the fork 45 moves forward toward the vehicle body 11, and when the fork motor 46 rotates in the other direction, it moves backward toward the vehicle body 11. In the front-rear direction X, the fork 45 is moved between the cargo handling position P1 and the retracted position P2 by the fork motor 46.

[0047] As shown in FIG. 7, the cargo handling position P1 is a position where the load W is handled by the fork 45. Handling the load W means supporting the load W on the fork 45 or lowering the load W. The cargo handling position P1 is a position where the fork 45 is moved forward away from the vehicle body 11.

[0048] As shown in FIG. 8, the retracted position P2 is a position where the fork 45 is shifted from the cargo handling position P1 so as to approach the vehicle body 11. That is, the retracted position P2 is a position where the fork 45 is closer to the vehicle body 11 than the cargo handling position P1 in the front-rear direction X. Therefore, the fork 45 shifts between the cargo handling position P1 and the retracted position P2 in the front-rear direction X.

[0049] The moment generated at the tip of the fork 45 by supporting the load W is greater when the fork 45 is in the cargo handling position P1 than when it is in the retracted position P2. That is, the moment generated by the load of the load W decreases as the fork 45 approaches the retracted position P2 from the cargo handling position P1.

[0050] Furthermore, the auxiliary member 61 described above is provided in the front-rear direction X on the side opposite to the side on which the load is handled by the forks 45 relative to the vehicle body 11. More specifically, the side on which the load is handled by the forks 45 is the front side of the vehicle body 11, and the auxiliary member 61 is provided on the rear side, which is opposite to the front side of the vehicle body 11.

[0051] <Vehicle Body Posture> The vehicle body 11 of the cargo handling mobile vehicle 10 can assume one of the following postures: standard posture T1, forward-tilted posture T2, or backward-tilted posture T3.

[0052] As shown by the solid line in Figure 3, in a side view of the cargo handling mobile body 10, the standard posture T1 is a posture in which the mounting surface 351 is parallel to the travel surface F. As shown by the dashed line in Figure 3, in a side view of the cargo handling mobile body 10, the forward-tilted posture T2 is a posture in which the vehicle body 11 is tilted forward more than in the standard posture T1. In a side view of the cargo handling mobile body 10, the mounting surface 351 in the forward-tilted posture T2 is downward at the front. Note that "downward at the front" means that the front side of the mounting surface 351 is lower than the rear side. The cargo handling mobile body 10 can assume the forward-tilted posture T2 while the forks 45 are in any of the following positions: the standard position, the tilt-up position, or the tilt-down position.

[0053] As shown by the dashed line in Figure 3 and in Figure 6, in a side view of the cargo handling mobile body 10, the rearward tilted posture T3 is a posture in which the vehicle body 11 is tilted further back than in the standard posture T1. In a side view of the cargo handling mobile body 10, the mounting surface 351 in the rearward tilted posture T3 is downward at the rear. Note that "downward at the rear" means that the rear side of the mounting surface 351 is lower than the front side. The cargo handling mobile body 10 can assume the rearward tilted posture T3 while keeping the forks 45 in any of the following positions: standard position, tilt-up position, or tilt-down position.

[0054] Furthermore, the cargo handling mobile body 10 can be positioned in any of the following orientations: standard orientation T1, forward-tilted orientation T2, or backward-tilted orientation T3, regardless of whether the forks 45 are in the cargo handling position P1 or the retracted position P2. The cargo handling mobile body 10 can be positioned in either the standard orientation T1 or the backward-tilted orientation T3, with the auxiliary member 61 in either the auxiliary orientation H1 or the non-auxiliary orientation H2. When the cargo handling mobile body 10 is in the forward-tilted orientation T2, the auxiliary member 61 is in the non-auxiliary orientation H2, but never in the auxiliary orientation H1.

[0055] The control device 50 can change the posture of the vehicle body 11 to a standard posture T1, a forward-tilted posture T2, or a rearward-tilted posture T3 by controlling the drive of the right-wheel drive motor 22 of the right-wheel drive unit 21 and the left-wheel drive motor 27 of the left-wheel drive unit 25. In addition, the control device 50 can move the position of the center of gravity G of the cargo handling mobile body 10 in the longitudinal direction X by controlling the drive of the right-wheel drive motor 22 of the right-wheel drive unit 21 and the left-wheel drive motor 27 of the left-wheel drive unit 25.

[0056] The position of the center of gravity G of the cargo handling mobile body 10 in the longitudinal direction X is determined based on the weight of the vehicle body 11, the cargo handling device 40, and the load W, as well as the posture of the vehicle body 11, when the load W is supported by the forks 45 in a cargo handling state.

[0057] As shown in Figure 3, in a side view of the cargo handling mobile body 10, a virtual line passing vertically through the axis L is defined as the reference line M. The angle formed between the reference line M and the center line N of the vehicle body 11 in the longitudinal direction X is defined as the inclination angle θ of the vehicle body 11.

[0058] In the standard posture T1, the centerline N coincides with the reference line M, and the center of gravity G is located on the reference line M. In this case, the inclination angle θ is zero. To position the center of gravity G on the reference line M, the cargo handling mobile body 10 uses the weight of the vehicle body 11 as a balance weight.

[0059] When the forks 45 move from the loading / unloading position P1 to the retracted position P2, or when the loading / unloading mobile body 10 moves, the position of the center of gravity G changes, and the inclination angle θ of the vehicle body 11 changes. For example, as shown by the dashed line in Figure 5, when the loading / unloading mobile body 10 is in a reference position T1 and the load W is supported by the forks 45 at the loading / unloading position P1, the position of the center of gravity G moves forward due to the moment generated by the load of the load W. The greater the weight of the load W and the greater the moment generated by the load of the load W, the further forward the position of the center of gravity G moves. On the other hand, when the loading / unloading mobile body 10 is displaced from a loading / unloading state to a non-loading state in a reference position T1, the position of the center of gravity G moves backward. Also, when acceleration occurs in conjunction with the movement of the loading / unloading mobile body 10 in a reference position T1, the position of the center of gravity G moves in the same direction as the direction of travel of the loading / unloading mobile body 10.

[0060] The control device 50 controls the posture of the vehicle body 11 to one of the above-described standard posture T1, forward-tilted posture T2, or backward-tilted posture T3 in order to adjust the tilt angle θ according to the position of the center of gravity G. As a result, the posture of the vehicle body 11 is controlled, and the cargo handling mobile body 10 is inverted.

[0061] <Control device> The control device 50 controls the entire cargo handling mobile body 10. The control device 50 also controls the right wheel drive unit 21 and the left wheel drive unit 25, the cargo handling device 40, and the auxiliary member 61.

[0062] The control device 50 comprises a processor and a memory unit. Examples of processors include a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a DSP (Digital Signal Processor). The memory unit includes RAM (Random Access Memory) and ROM (Read Only Memory). The memory unit stores program code or instructions configured to cause the processor to execute processing. The memory unit, i.e., the computer-readable medium, includes any available medium accessible by a general-purpose or dedicated computer. The control device 50 may also be composed of hardware circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control device 50, which is a processing circuit, may include one or more processors operating according to a computer program, one or more hardware circuits such as an ASIC or FPGA, or a combination thereof.

[0063] As shown in Figure 4, the control device 50 includes an attitude control unit 51, a position control unit 52, a tilt control unit 54, a fork control unit 55, and an auxiliary member control unit 56. An input unit 57 and a communication unit 58 are connected to the control device 50.

[0064] <Input Unit> The input unit 57 outputs various command values ​​for driving the cargo handling mobile body 10. The input unit 57 inputs the various command values ​​to the control device 50.

[0065] <Communication Unit> The communication unit 58 receives information regarding the weight of the load W being transported by the cargo handling mobile unit 10 as a load signal from a higher-level control unit (not shown). The communication unit 58 outputs the received load signal to the attitude control unit 51 and the auxiliary member control unit 56.

[0066] <Position Control Unit> The position command value, which is one of the command values ​​input by the input unit 57, is a command value for operating the cargo handling mobile body 10, such as the movement path and movement speed of the cargo handling mobile body 10. The position command value related to the movement path is, for example, a command value that commands the position of the cargo handling mobile body 10 from the standby position, through the loading position, to the unloading position. According to this position command value, the cargo handling mobile body 10 moves from the standby position to the loading position, and at the loading position, performs loading, which is one of the cargo operations, and supports the load W on the upper surface 45a of the forks 45. Furthermore, according to the position command value, the cargo handling mobile body 10 moves from the loading position to the unloading position with the load W supported on the upper surface 45a of the forks 45. Then, according to the position command value, the cargo handling mobile body 10 performs unloading, which is one of the cargo operations, at the unloading position. Note that the position command value related to the movement path may be changed arbitrarily. For example, the position command value related to the movement path may be from the standby position to the loading position, or from the loading position to the unloading position. The position command value related to the movement speed is a command value for commanding the speed at which the cargo handling mobile body 10 moves. The movement speed can be changed arbitrarily.

[0067] As shown in Figure 3, a loading platform 100 is installed at the loading position. A pallet 101 is placed on the mounting surface 100a of the loading platform 100. The pallet 101 has pallet holes 101a through which a pair of forks 45 can be inserted and removed. The load W is placed on the pallet 101. Of the hole-forming surfaces that define the pallet holes 101a, the surface located on the upper side in the vertical direction Z is the contact surface 101b. On the pallet 101 placed on the mounting surface 100a, the contact surface 101b is parallel to the travel surface F. However, due to slight inclination of the loading platform 100 or the mounting surface 100a, the contact surface 101b may be slightly inclined from parallel to the travel surface F. The loading / unloading mobile body 10 then moves to the loading position where a pair of forks 45 can be inserted into the pallet holes 101a, according to the position command value.

[0068] The position control unit 52 calculates the acceleration and target speed of the cargo handling mobile body 10 according to the position command value output from the input unit 57. The position control unit 52 drives the right wheel drive motor 22 and the left wheel drive motor 27 according to the calculated acceleration and target speed. As a result, the cargo handling mobile body 10 travels along the travel path at the target speed.

[0069] The position control unit 52 receives a detection signal related to the rotation angle of the right drive wheel 31 from the right wheel encoder 24. The position control unit 52 also receives a detection signal related to the rotation angle of the left drive wheel 32 from the left wheel encoder 28. The position control unit 52 acquires the detection signal output by both the right wheel encoder 24 and the left wheel encoder 28. Based on the acquired detection signals, the position control unit 52 acquires the rotational angular velocity of both the right drive wheel 31 and the left drive wheel 32. Based on the acquired rotational angular velocity, the position control unit 52 drives the right wheel drive motor 22 and the left wheel drive motor 27. Under the control of the position control unit 52, the cargo handling mobile body 10 moves along the movement path at the target speed according to the position command value.

[0070] <Attitude Control Unit> The input unit 57 inputs an attitude command value to the attitude control unit 51. The attitude command value is a command value for commanding the attitude angle of the vehicle body 11. The attitude control unit 51 controls the drive of the right wheel drive unit 21 and the left wheel drive unit 25 according to the attitude command value, and controls the attitude of the vehicle body 11 by oscillating the vehicle body 11 with the axis L as the pivot point.

[0071] As shown in Figure 4, the attitude control unit 51 is connected to a measurement unit 51a, a right-wheel drive motor 22, and a left-wheel drive motor 27. The measurement unit 51a is an IMU (Inertial Measurement Unit). The measurement unit 51a is built into the control device 50. The measurement unit 51a is also connected to the auxiliary member control unit 56. The measurement unit 51a detects three-dimensional inertial motion. Inertial motion consists of translational and rotational motion in the three orthogonal axes. The measurement unit 51a detects translational motion using a built-in acceleration sensor and rotational motion using a built-in gyro sensor.

[0072] The measurement unit 51a measures the inclination angle θ of the vehicle body 11 at any given time, such as when the load W is supported by the forks 45 at the loading / unloading position P1, when the load W is lowered from the forks 45 at the loading / unloading position P1, when the load W is supported at the retraction position P2, etc. The inclination angle θ measured by the measurement unit 51a changes in accordance with the change in the posture of the vehicle body 11. In other words, the inclination angle θ is the amount of change that changes according to the position of the center of gravity G in the longitudinal direction X of the loading / unloading mobile body 10. The measurement unit 51a detects the change in the inclination angle θ of the vehicle body 11 in the longitudinal direction X.

[0073] The attitude control unit 51 acquires a detection signal related to the tilt angle θ measured by the measurement unit 51a. Based on the acquired detection signal related to the tilt angle θ, the attitude control unit 51 synchronously drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25. As a result, the attitude of the vehicle body 11 is controlled to a standard attitude T1, a forward-tilted attitude T2, or a backward-tilted attitude T3 depending on the position of the center of gravity G, and the cargo handling mobile body 10 is inverted in the controlled attitude. Therefore, in order to invert the cargo handling mobile body 10, the attitude control unit 51 swings the vehicle body 11 with the right wheel drive unit 21 and the left wheel drive unit 25 to move the position of the center of gravity G in the longitudinal direction X.

[0074] The attitude control unit 51 acquires the load signal output by the communication unit 58. This load signal is input to the attitude control unit 51 before the cargo handling mobile body 10 is inverted while the load W is supported by the forks 45 at the cargo handling position P1. Based on the acquired load signal, the attitude control unit 51 derives the moment generated when the load is picked up, the moment generated when the load is unloaded, and the moment generated at the retraction position P2. The moments may be derived by calculation by the attitude control unit 51, or they may be derived using maps or tables stored in the attitude control unit 51. In short, as long as the attitude control unit 51 can derive the moments from the acquired load signal, the method of derivation is arbitrary.

[0075] The resulting moment is a moment that acts in a direction that rotates the base end of the fork 45 downward when it is in the loading / unloading position P1 or the retracted position P2. When such a moment is generated in the loading / unloading mobile body 10, the loading / unloading mobile body 10 will try to move forward by lowering the tips of the forks 45. In other words, when the load W is supported by the forks 45 in the loading / unloading position P1 or the retracted position P2, the center of gravity G will move forward from the reference line M, so the loading / unloading mobile body 10 will try to move forward. However, since the load W is closer to the axis L of the vehicle body 11 in the retracted position P2, the moment generated in the retracted position P2 will be smaller than the moment generated in the loading / unloading position P1.

[0076] In light of the generation of the moment described above, the attitude control unit 51, before inverting the cargo handling mobile body 10 with the load W supported by the forks 45, synchronously drives the right wheel drive motor 22 and the left wheel drive motor 27 based on the derived moment to rotate the right drive wheel 31 and the left drive wheel 32 so that the cargo handling mobile body 10 moves backward. In other words, the attitude control unit 51 rotates the right drive wheel 31 and the left drive wheel 32 based on the load signal to move the center of gravity G to a position behind the reference line M. As a result, the attitude control unit 51 moves the center of gravity G to a position further back than the center of gravity G when the load W is not supported by the forks 45.

[0077] As described above, in order to rotate the right drive wheel 31 and the left drive wheel 32, the attitude control unit 51 derives the amount to drive the right wheel drive motor 22 and the left wheel drive motor 27 at the same time as deriving the moment. The amount of drive of the right wheel drive motor 22 and the left wheel drive motor 27 is also the amount of rotation of the right drive wheel 31 and the left drive wheel 32. Note that the amount of drive of the right wheel drive motor 22 and the left wheel drive motor 27 may be derived by calculation by the attitude control unit 51, or may be derived using a map or table that links the amount of drive to the moment.

[0078] Therefore, based on the derived moment and drive amount, the attitude control unit 51 synchronously drives the right wheel drive motor 22 and the left wheel drive motor 27 to rotate the right drive wheel 31 and the left drive wheel 32 so that the cargo handling mobile body 10 moves in reverse. In other words, the attitude control unit 51 moves the center of gravity G of the cargo handling mobile body 10 further back than when the load W is not supported by the forks 45, specifically, further back than the reference line M.

[0079] As shown in Figure 6, when the attitude control unit 51 moves the center of gravity G to the rear of the reference line M, the vehicle body 11 adopts a rearward tilt posture T3. In other words, before inverting the cargo handling mobile body 10 with the load W supported by the forks 45, the attitude control unit 51 moves the center of gravity G to the rear of the reference line M and sets the posture of the vehicle body 11 to a rearward tilt posture T3. As a result, the attitude control unit 51 can create a state in which the cargo handling mobile body 10 has a pseudo-balance weight. In other words, the cargo handling mobile body 10 can be controlled by the attitude control unit 51 to create a pseudo-balance weight.

[0080] Furthermore, before changing from a state where the load W is supported by the forks 45 to a state where the load W is released and the load W is not supported by the forks 45, specifically before unloading, the attitude control unit 51 moves the center of gravity G based on the load signal related to the weight of the load W. In this case, in order to invert the cargo handling mobile body 10 when the load W is not supported by the forks 45, the attitude control unit 51 swings the vehicle body 11 with the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the center of gravity G of the cargo handling mobile body 10 in the longitudinal direction X. Specifically, before changing from a state where the load W is supported by the forks 45 to a state where the load W is released and the load W is not supported, the attitude control unit 51 moves the center of gravity G to a position behind the reference line M, which is behind the axis L, which is the pivot center.

[0081] When the attitude control unit 51 moves the center of gravity G to the rear of the reference line M, the vehicle body 11 assumes a rearward tilt posture T3, as shown by the dashed line in Figure 3. In other words, before inverting the cargo handling mobile body 10 with the load W released from the forks 45, the attitude control unit 51 moves the center of gravity G to the rear of the reference line M and sets the vehicle body 11 to a rearward tilt posture T3. As a result, the attitude control unit 51 can create a state in which the cargo handling mobile body 10 has a simulated balance weight. In other words, the cargo handling mobile body 10 can be simulated to have a balance weight by the control of the attitude control unit 51.

[0082] <Tilt Control Unit> The input unit 57 inputs a cargo handling command value, which is one of the command values, to the tilt control unit 54. The cargo handling command value includes a command value for commanding the angle of the forks 45 and a command value for commanding the position of the forks 45. The tilt control unit 54 is connected to the tilt motor 42 and the tilt encoder 43. The tilt encoder 43 detects the rotation angle of the tilt motor 42 and outputs a detection signal to the tilt control unit 54. The tilt control unit 54 drives the tilt motor 42 according to the cargo handling command value and based on the detection signal related to the rotation angle detected by the tilt encoder 43.

[0083] During cargo handling, the tilt control unit 54 controls the position of the forks 45 to either the reference position, the tilt-up position, or the tilt-down position according to the position command value. Before the load W is supported by the forks 45, the tilt control unit 54 controls the drive of the tilt motor 42 to set the rotational position of the forks 45 to the reference position. Also, before the load W is supported by the forks 45 and while the cargo handling mobile body 10 is moving, the tilt control unit 54 sets the rotational position of the forks 45 to either the reference position, the tilt-up position, or the tilt-down position. When inserting the forks 45 into the pallet hole 101a, the tilt control unit 54 controls the drive of the tilt motor 42 to set the rotational position of the forks 45 to the reference position. After unloading, when lifting the load W, the tilt control unit 54 controls the drive of the tilt motor 42 to set the rotational position of the forks 45 to the tilt-up position. Furthermore, when unloading the load W onto the loading platform 100, the tilt control unit 54 controls the drive of the tilt motor 42 to set the rotational position of the fork 45 to the tilt-down position.

[0084] <Fork Control Unit> The fork control unit 55, which is the support member control unit, is connected to the fork motor 46 and the encoder 47. The encoder 47 detects the rotation angle of the fork motor 46 and outputs a detection signal to the fork control unit 55. The fork control unit 55 drives the fork motor 46 according to the position command value and based on the detection signal related to the rotation angle detected by the encoder 47.

[0085] When loading the load W from the loading platform 100, the fork control unit 55 controls the drive of the fork motor 46 to move the forks 45 to the loading / unloading position P1. Furthermore, after supporting the load W with the forks 45, the fork control unit 55 controls the drive of the fork motor 46 to move the forks 45 to the retracted position P2. In other words, the fork control unit 55 controls the fork motor 46 to position the forks 45 at either the loading / unloading position P1 or the retracted position P2. The fork control unit 55 can move the forks 45 between the loading / unloading position P1 and the retracted position P2, and can also position the forks 45 between the loading / unloading position P1 and the retracted position P2.

[0086] <Auxiliary Member Control Unit> The auxiliary member control unit 56, which is the mode control unit, is connected to the auxiliary member motor 66 and the encoder 67. The encoder 67 detects the rotation angle of the auxiliary member motor 66 and outputs a detection signal to the auxiliary member control unit 56. The auxiliary member control unit 56 drives the auxiliary member motor 66 according to the inclination angle θ measured by the measurement unit 51a. The vertical position Z of the auxiliary wheel 65 changes according to the rotation angle of the auxiliary member motor 66. The auxiliary member control unit 56 controls the auxiliary member motor 66 to control the distance between the running surface F and the auxiliary wheel 65. In other words, the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the position of the leg portion 64 relative to the vehicle body 11. The auxiliary member control unit 56 also controls the auxiliary member motor 66 to change the distance between the running surface F and the auxiliary wheel 65. The auxiliary member control unit 56 controls the auxiliary member motor 66 to change the configuration of the auxiliary member 61 to either an auxiliary configuration H1 in which the auxiliary wheels 65 are in contact with the running surface F, or a non-auxiliary configuration H2 in which the auxiliary wheels 65 are not in contact with the running surface F.

[0087] <Operation of the cargo handling mobile unit> The operation of the cargo handling mobile unit 10 is started by the operator after various command values ​​such as the movement path and movement speed are input to the control device 50 by the input unit 57.

[0088] The control device 50 performs movement processing and cargo handling processing. The body 11 of the cargo handling mobile unit 10 is controlled to a reference posture T1, and the position of the forks 45 in the longitudinal direction X and the rotational position are controlled to be the cargo handling position P1 and the reference position, respectively. Furthermore, the auxiliary member control unit 56 controls the configuration of the auxiliary member 61 to a non-auxiliary configuration H2. In the non-auxiliary configuration H2 of the auxiliary member 61, the auxiliary wheels 65 are raised to a position where they do not come into contact with the running surface F even when the cargo handling mobile unit 10 is tilted for travel.

[0089] Before transporting the load W, the control device 50 receives a command from the higher-level control unit via the communication unit 58 and receives the load signal of the load W. The communication unit 58 outputs the input load signal of the load W to the attitude control unit 51. The attitude control unit 51 acquires the load signal from the communication unit 58 and, based on the load signal, derives the moment due to the load of the load W, the moment due to the weight of the vehicle body 11, and the drive amount of the right wheel drive motor 22 and the left wheel drive motor 27.

[0090] <Cargo Handling Process> As shown in Figure 5, the cargo handling mobile body 10 moves along the movement path using two wheels, the right drive wheel 31 and the left drive wheel 32, to a position away from the load W on the loading platform 100. Specifically, the cargo handling mobile body 10 moves using two wheels until just before the load picking position. Next, the attitude control unit 51 drives the right wheel drive motor 22 and the left wheel drive motor 27 in synchronous motion using the drive amounts of the right wheel drive motor 22 and the left wheel drive motor 27 derived based on the load signal. In other words, the attitude control unit 51 moves the center of gravity G to the rear of the reference line M. Then, in response to the load signal, the center of gravity G of the cargo handling mobile body 10 moves to the rear of the reference line M. As a result, before the load W is supported by the forks 45, the vehicle body 11 tilts to the rear due to the artificially formed balance weight, and the cargo handling mobile body 10 takes a rearward tilted posture T3.

[0091] The tilt angle θ of the rearward-tilted vehicle body 11 is measured by the measuring unit 51a. The auxiliary member control unit 56 changes the position of the legs 64 relative to the vehicle body 11 in the direction in which the auxiliary wheels 65 descend, based on the amount of drive of the auxiliary member motor 66 derived from the tilt angle θ measured by the measuring unit 51a. As a result, the auxiliary wheels 65 move toward the running surface F. Then, as shown in Figure 6, the mode of the auxiliary member 61 changes to auxiliary mode H1 due to the contact of the auxiliary wheels 65 with the running surface F, and the vehicle body 11 is supported by the legs 64. Therefore, the attitude control unit 51 tilts the vehicle body 11 in the front-rear direction X toward the opposite side from the side where the load is unloaded by the forks 45, and the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the position of the legs 64 in the direction in which the auxiliary wheels 65 come into contact with the running surface F in order to change the mode of the auxiliary member 61 to auxiliary mode H1. Furthermore, at a position further from the load W than the loading position where the cargo handling mobile body 10 performs cargo handling, the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the configuration of the auxiliary member 61 to auxiliary configuration H1, thereby changing the position of the leg portion 64 relative to the vehicle body 11 and bringing the auxiliary wheel 65 into contact with the running surface F.

[0092] Next, the position control unit 52 controls the drive of the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the cargo handling mobile body 10 forward on three wheels to the loading position. Therefore, when the cargo handling mobile body 10 is moving, the auxiliary member control unit 56 sets the mode of the auxiliary member 61 to auxiliary mode H1.

[0093] As shown in Figure 7, the pair of forks 45 are inserted into the pallet holes 101a. Next, although not shown, the tilt control unit 54 drives the tilt motor 42 to move the pair of forks 45 to the tilt-up position. At this point, the contact surface 101b of the pallet 101 comes into contact with the upper surfaces 45a of the pair of forks 45, and the load W is supported on the upper surfaces 45a of the forks 45 via the pallet 101. In other words, the cargo handling mobile unit 10 uses the forks 45 to pick up the load.

[0094] Next, the tilt control unit 54 drives the tilt motor 42 to move the pair of forks 45 to the reference position, while the fork control unit 55 controls the drive of the fork motor 46 to move the forks 45 to the retracted position P2. At this time, the position control unit 52 slightly reverses the cargo handling mobile body 10. The reverse movement of the cargo handling mobile body 10 is performed by three-wheeled movement.

[0095] As shown in Figure 8, the load W approaches the vehicle body 11. As a result, the moment due to the load W is smaller than when the load W is in the loading / unloading position P1. In other words, the moment due to the weight of the vehicle body 11 is relatively larger than the moment due to the load W. Also, compared to when the load W is in the loading / unloading position P1, the center of gravity G of the loading / unloading mobile body 10 approaches the reference line M, and the posture of the vehicle body 11 approaches the reference posture T1. However, the center of gravity G is located behind the reference line M, and the vehicle body 11 remains in the rearward tilt posture T3. As a result, the posture of the vehicle body 11 is maintained in the rearward tilt posture T3 by the artificially formed balance weight. Furthermore, the contact of the auxiliary wheels 65 with the running surface F is maintained, and the rearward tilt posture T3 of the vehicle body 11 remains assisted by the auxiliary member 61 of auxiliary configuration H1. Therefore, in the cargo handling mobile body 10, during cargo handling by the cargo handling device 40, the fork control unit 55 moves the forks 45 supporting the load W from the cargo handling position P1 to the retracted position P2.

[0096] When the cargo handling device 40 described above is used to unload the cargo W, the auxiliary member control unit 56 changes the position of the legs 64 in synchronization with the movement of the forks 45 supporting the cargo W from the loading / unloading position P1 to the retraction position P2, so as to raise the vehicle body 11 toward the side where the cargo handling was performed. Specifically, the auxiliary member control unit 56 moves the legs 64 in a direction that brings the auxiliary wheels 65 into contact with the running surface F, in synchronization with the movement of the forks 45 supporting the cargo W from the loading / unloading position P1 to the retraction position P2, thereby changing the position of the legs 64 relative to the vehicle body 11.

[0097] Next, the attitude control unit 51 tilts the vehicle body 11 in a direction that will straighten the vehicle body 11, which has been tilted to the side opposite to the side where the cargo handling was performed. Synchronized with the tilting of the vehicle body 11 by the attitude control unit 51, the auxiliary member control unit 56 changes the position of the legs 64 in a direction that will straighten the vehicle body 11. In other words, the auxiliary member control unit 56 changes the position of the legs 64 in a direction that will move the auxiliary wheels 65 away from the leg support 63. Based on the detection signal from the measurement unit 51a, the auxiliary member control unit 56 drives the auxiliary member motor 66 until the tilt angle θ of the vehicle body 11 reaches a desired angle, thereby changing the position of the legs 64 relative to the vehicle body 11. The desired angle of tilt angle θ is the angle at which the center of gravity G is located behind the reference line M. As a result, in synchronization with the movement of the legs 64, the cargo handling mobile body 10 inverts in a rearward tilted posture T3. In this backward-tilted position T3, the cargo handling mobile body 10 will remain upright even without support from its legs 64.

[0098] Next, the auxiliary member control unit 56 drives the auxiliary member motor 66 based on the inclination angle θ measured by the measurement unit 51a to move the leg portion 64 in a direction that separates the auxiliary wheel 65 from the running surface F. In other words, the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the configuration of the auxiliary member 61 to the non-auxiliary configuration H2. At this time, the auxiliary member control unit 56 changes the position of the leg portion 64 relative to the vehicle body 11 so that the auxiliary wheel 65 is separated from the running surface F by a desired distance. When moving the leg portion 64 in a direction that separates the auxiliary wheel 65 from the running surface F, the auxiliary member control unit 56 changes the position of the leg portion 64 relative to the vehicle body 11 so that the auxiliary wheel 65 is separated from the running surface F by a desired distance.

[0099] The desired distance is such that, when the cargo handling mobile vehicle 10 is in motion, the auxiliary wheels 65 do not come into contact with the running surface F even if the vehicle body 11 tilts backward. Furthermore, the desired distance is such that, when the power supply to the cargo handling mobile vehicle 10 is cut off and the rotation of the right drive wheel 31 and left drive wheel 32 stops, the auxiliary wheels 65 can come into contact with the running surface F, preventing the vehicle body 11 from tipping over, even if the vehicle body 11 tilts backward. This desired distance is predetermined through experiments using the cargo handling mobile vehicle 10 and is stored in the control device 50.

[0100] As a result, as shown in Figure 9, at the retraction position P2, with the load W supported on the upper surface 45a of the forks 45 via the pallet 101, the cargo handling mobile body 10 inverts in a rearward-tilted position T3.

[0101] <Processing during movement> The cargo handling mobile body 10 performs processing during movement in order to move to the unloading position. The processing during movement is also performed when the cargo handling mobile body 10 moves from the standby position to the loading position. During the processing during movement, the cargo handling mobile body 10 supports the load W on the forks 45 at the retraction position P2 and travels in a rearward-tilted position T3. At this time, the configuration of the auxiliary member 61 is the non-auxiliary configuration H2.

[0102] The position control unit 52 calculates the acceleration and target speed of the cargo handling mobile body 10 based on the movement speed included in the movement command value input from the input unit 57. Next, the attitude control unit 51 drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the center of gravity G further behind the reference line M, thereby changing the attitude of the vehicle body 11 to a more rearward tilted attitude T3. As shown by the dashed line in Figure 3, during the movement processing of the cargo handling mobile body 10, the auxiliary wheels 65 of the legs 64 are separated from the running surface F by a desired distance. In other words, the auxiliary member control unit 56 changes the position of the legs 64 in a direction that separates the auxiliary wheels 65 from the running surface F, thereby changing the mode of the auxiliary member 61 to a non-auxiliary mode H2.

[0103] When the cargo handling vehicle 10 is moving, the vehicle body 11 tilts in the direction of travel due to acceleration. Therefore, the attitude control unit 51 controls the position of the center of gravity G to maintain an inverted state at the calculated acceleration and target speed, thereby creating a rearward-tilted posture T3.

[0104] Next, the position control unit 52 drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the vehicle body 11. At this time, the vehicle body 11 moves while accelerating in a rearward-tilted posture T3. Based on the detection signal from the measurement unit 51a, the posture control unit 51 drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to adjust the position of the center of gravity G in the longitudinal direction X. Specifically, as the acceleration of the cargo handling mobile body 10 increases, the posture control unit 51 moves the center of gravity G to the rearward side and increases the tilt angle θ. Due to this movement processing, the cargo handling mobile body 10 moves while maintaining an inverted state in a rearward-tilted posture T3. Therefore, when the cargo handling mobile body 10 is traveling with the load W supported on the forks 45 at the retracted position P2, the posture control unit 51 sets the vehicle body 11 in a posture tilted in the direction of travel of the cargo handling mobile body 10. Then, even if the inclination angle θ increases and the acceleration of the cargo handling mobile body 10 increases, the auxiliary wheels 65 are kept at a desired distance from the running surface F so that they do not come into contact with the running surface F. In other words, the form of the auxiliary member 61 is the non-auxiliary form H2. After that, the cargo handling mobile body 10 reduces its speed so that it can come to a stop at the unloading position. As the speed of the cargo handling mobile body 10 decreases, the attitude control unit 51 reduces the inclination angle θ of the vehicle body 11, bringing the attitude of the vehicle body 11 closer to the reference attitude T1.

[0105] The cargo handling mobile unit 10 moves along its path until it is just before the unloading position. In other words, the cargo handling mobile unit 10 moves on two wheels to a position further away from the load W than the position where the cargo handling mobile unit 10 will perform the cargo handling. The cargo handling mobile unit 10 has its forks 45 facing directly towards the unloading position.

[0106] <Load Handling Process> The attitude control unit 51 drives the right wheel drive motor 22 and the left wheel drive motor 27 in synchronous motion using the drive amounts of the right wheel drive motor 22 and the left wheel drive motor 27 derived from the load signal. In other words, the attitude control unit 51 moves the center of gravity G to the rear of the reference line M. As a result, the center of gravity G of the load handling mobile body 10 moves to the rear of the reference line M in response to the load signal.

[0107] The tilt angle θ of the rearward-tilted vehicle body 11 is measured by the measuring unit 51a. The auxiliary member control unit 56 changes the position of the legs 64 relative to the vehicle body 11 in the direction of downward movement of the auxiliary wheels 65, using the amount of drive of the auxiliary member motor 66 derived based on the tilt angle θ measured by the measuring unit 51a. As a result, the auxiliary wheels 65 move toward the running surface F. In other words, the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the mode of the auxiliary member 61 to auxiliary mode H1. Then, the vehicle body 11 is supported by the legs 64 due to the contact of the auxiliary wheels 65 with the running surface F. Therefore, the attitude control unit 51 tilts the vehicle body 11 in the front-rear direction X toward the side opposite to the side from which the load is unloaded by the forks 45, and the auxiliary member control unit 56 changes the position of the legs 64 in the direction of contacting the auxiliary wheels 65 with the running surface F.

[0108] Next, the position control unit 52 controls the drive of the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the cargo handling mobile body 10 forward on three wheels to the unloading position. Then, the pair of forks 45 are positioned above the unloading position. Next, the tilt control unit 54 drives the tilt motor 42 to move the pair of forks 45 to the tilt-down position. Then, the pallet 101 is placed at the unloading position.

[0109] According to the first embodiment described above, the following effects can be obtained. (1-1) When the cargo handling mobile body 10 is traveling, the fork control unit 55 positions the forks 45 in the retracted position P2. For example, compared to the case when the cargo handling mobile body 10 is traveling with the forks 45 in the cargo handling position P1, the weight of the vehicle body 11 used as a balance weight to invert the vehicle body 11 can be reduced. Before the cargo handling mobile body 10 travels, the fork control unit 55 moves the forks 45 from the cargo handling position P1 to the retracted position P2. In addition, the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the mode of the auxiliary member 61 to auxiliary mode H1. As a result, the auxiliary wheels 65 are in contact with the travel surface F. As a result, the vehicle body 11 can be supported by the auxiliary member 61 in auxiliary mode H1, so the cargo handling mobile body 10 can move the forks 45 from the cargo handling position P1 to the retracted position P2 in a stable state.

[0110] Furthermore, during cargo handling by the cargo handling mobile vehicle 10, the auxiliary member control unit 56 controls the auxiliary member motor 66 to bring the auxiliary wheels 65 into contact with the running surface F, thereby changing the configuration of the auxiliary member 61 to auxiliary configuration H1. This allows for more stable cargo handling compared to the case where cargo handling is performed by inverting the vehicle body 11 using only the left and right pair of drive wheels 31 and 32. As a result, the cargo handling mobile vehicle 10 can perform cargo handling stably and the vehicle body 11 can be made lighter.

[0111] (1-2) In order to invert the cargo handling mobile body 10 with the load W supported by the forks 45, the attitude control unit 51 moves the center of gravity G back and forth to swing the vehicle body 11. In addition, the fork control unit 55 moves the forks 45 from the cargo handling position P1 to the retracted position P2 during cargo handling, thereby relatively reducing the moment due to the load W. As a result, even if the vehicle body 11 is swung by the attitude control unit 51 to create a pseudo-balance weight on the cargo handling mobile body 10, the vehicle body 11 that functions as that balance weight can be made lighter.

[0112] (1-3) The cargo handling mobile vehicle 10 can tilt its body 11 in advance before supporting the load W with the forks 45 by using a balance weight artificially created by the control of the attitude control unit 51. Then, with the cargo handling mobile vehicle 10 having artificially created a balance weight before supporting the load W with the forks 45, the auxiliary member motor 66 controlled by the auxiliary member control unit 56 brings the auxiliary wheels 65 into contact with the running surface F, changing the configuration of the auxiliary member 61 to auxiliary configuration H1. As a result, the cargo handling mobile vehicle 10 can stabilize the state in which the artificial balance weight has been created by supporting the body 11 with the legs 64.

[0113] (1-4) In the cargo handling mobile vehicle 10, when the forks 45 are tilted up after loading and when the forks 45 are tilted down for unloading, the vehicle body 11 is supported by the legs 64 in the auxiliary member 61 in auxiliary mode H1. Therefore, the cargo handling mobile vehicle 10 can perform the operation of the forks 45 in a stable state.

[0114] (1-5) Before moving the cargo handling mobile vehicle 10 after unloading, the auxiliary member control unit 56 moves the auxiliary wheels 65 away from the running surface F to change the configuration of the auxiliary members 61 to the non-auxiliary configuration H2. As a result, when the cargo handling mobile vehicle 10 is moving, even if the vehicle body 11 tilts due to acceleration, the auxiliary wheels 65 do not come into contact with the running surface F. Therefore, the cargo handling mobile vehicle 10 can increase its acceleration and speed compared to when it is moving with the auxiliary wheels 65 in contact with the running surface F. Furthermore, since the vehicle body 11 of the cargo handling mobile vehicle 10 can be made lighter, the acceleration of the cargo handling mobile vehicle 10 can be increased quickly.

[0115] (1-6) Before moving the cargo handling mobile vehicle 10 after unloading, the auxiliary member control unit 56 moves the auxiliary wheels 65 away from the running surface F to change the configuration of the auxiliary member 61 to the non-auxiliary configuration H2. The distance of the auxiliary wheels 65 from the running surface F in the non-auxiliary configuration H2 is the distance at which the auxiliary wheels 65 contact the running surface F when the power supply to the cargo handling mobile vehicle 10 is stopped while the cargo handling mobile vehicle 10 is in motion, causing the vehicle body 11 to tilt in the direction of travel. This prevents the vehicle body 11 from tipping over even if the cargo handling mobile vehicle 10 stops moving and the vehicle body 11 tilts in the direction of travel while the cargo handling mobile vehicle 10 is in motion.

[0116] (1-7) Before moving the cargo handling mobile vehicle 10 after cargo handling, the attitude control unit 51 tilts the vehicle body 11 in a direction that straightens the vehicle body 11 which has tilted to the opposite side from the side on which cargo handling was performed. In synchronization with this, the auxiliary member control unit 56 changes the position of the legs 64 in a direction that straightens the vehicle body 11. By changing the position of the legs 64 relative to the vehicle body 11, the swinging of the vehicle body 11 in the direction that straightens the vehicle body 11 can be assisted. As a result, the torque required for the right wheel drive motor 22 and the left wheel drive motor 27 can be reduced compared to the case where the vehicle body 11 is straightened only by the swinging of the vehicle body 11 controlled by the attitude control unit 51.

[0117] (1-8) In synchronization with moving the forks 45 supporting the load W from the loading / unloading position P1 to the retraction position P2, the auxiliary member control unit 56 changes the position of the legs 64 so that the vehicle body 11 is raised toward the side where the load was loaded. For example, compared to the case where the auxiliary member control unit 56 changes the position of the legs 64 so that the vehicle body 11 is raised toward the side where the load was loaded after the forks 45 have been moved from the loading / unloading position P1 to the retraction position P2, the torque required for the auxiliary member motor 66 can be reduced. As a result, the load handling mobile body 10 can be made lighter as the vehicle body 11 is swung toward the upright side by the auxiliary member motor 66.

[0118] (1-9) The cargo handling mobile vehicle 10 supports its body 11 with adjustable legs 64, so that even if the weight of the load W supported by the forks 45 increases, it can maintain a stable rearward tilt posture T3. Therefore, by changing the position of the auxiliary wheels 65 with the auxiliary member control unit 56, the artificially created balance weight can be adjusted to match the weight of the load W to maintain the rearward tilt posture T3. As a result, when tilting the body 11 toward the reference posture T1 in order to move the cargo handling mobile vehicle 10, the amount of tilting of the body 11 can be reduced, and the time required to tilt the body 11 can be shortened.

[0119] (1-10) The auxiliary member 61 is equipped with auxiliary wheels 65 as contact parts with the running surface F. Therefore, when the cargo handling mobile body 10 is moved with the auxiliary member 61 in contact with the running surface F, it becomes a three-wheeled vehicle, and the movement of the cargo handling mobile body 10 becomes stable and smooth.

[0120] (1-11) When the cargo handling mobile vehicle 10 is at a position further from the load W than the position where it is performing cargo handling, the auxiliary member control unit 56 controls the auxiliary member motor 66 to change the position of the legs 64 relative to the vehicle body 11 so that the auxiliary wheels 65 come into contact with the running surface F. In other words, when the cargo handling mobile vehicle 10 is at a position further from the load W than the position where it is performing cargo handling, the auxiliary member control unit 56 changes the configuration of the auxiliary member 61 to auxiliary configuration H1. As a result, when the cargo handling mobile vehicle 10 travels to a position further from the load W than the position where it is performing cargo handling, the cargo handling mobile vehicle 10 can travel in a stable state.

[0121] (Second Embodiment) Next, a second embodiment of the cargo handling mobile body 10 will be described. Since the second embodiment is configured only by modifying the cargo handling device 40 of the first embodiment, a detailed explanation of the similar parts will be omitted.

[0122] As shown in Figures 10 and 11, the cargo handling device 40 of the cargo handling mobile body 10 includes a tilt motor 42, a tilt encoder 43, a bar 44, a fork 45, and a pair of arms 70 on the left and right sides. The arms 70 are connected to the fork 45. The cargo handling device 40 allows adjustment of the height of the fork 45 and the position of the fork 45 in the front-rear direction X by adjusting the shape of the arms 70. The cargo handling device 40 picks up or unloads a load W by swinging the fork 45 at the adjusted height, and also supports the load W with the fork 45.

[0123] Each of the pair of arms 70 includes a first joint 71, a second joint 72, a third joint 73, a first link 74, and a second link 75. In other words, each of the pair of arms 70 includes multiple links 74, 75 and joints 71, 72 that connect the links 74, 75 to each other. Each of the pair of arms 70 is capable of changing the relative angle between the links 74, 75 connected by the joints 71, 72.

[0124] The first joint 71, the second joint 72, and the third joint 73 are each rotatable joints. The first link 74 and the second link 75 are rod-shaped rigid bodies. The first link 74 is shorter than the second link 75.

[0125] A pair of first joints 71 are positioned on both sides of the housing 35 in the left-right direction Y. Each first joint 71 includes a first joint motor 71a and a first encoder 71b. The first end 74a of the first link 74 is connected to the first joint 71. When the first joint motor 71a is driven, the first link 74 swings via the first joint 71. This causes the arm 70 to swing.

[0126] The second end 74b of the first link 74 is connected to the first end 75a of the second link 75 via the second joint 72. The second joint 72 includes a second joint motor 72a and a second encoder 72b. When the second joint motor 72a is driven, the second link 75 swings via the second joint 72. When the second link 75 swings, the relative angle between the first link 74 and the second link 75 changes. In this way, by changing the relative angle between the first link 74 and the second link 75, the arm 70 can be extended or bent.

[0127] The second end 75b of the second link 75 is connected to the fork 45 via a third joint 73. The third joint 73 includes a tilt motor 42 and a tilt encoder 43. When the tilt motor 42 is driven, the fork 45 swings via the third joint 73. As the fork 45 swings, the relative angle of the fork 45 with respect to the second link 75 changes. The pair of forks 45 are integrated by a bar 44.

[0128] Each of the pair of arms 70 has a tip portion 70b and a base portion 70a opposite to the tip portion 70b. The base portion 70a is the first end 74a of the first link 74. The tip portion 70b is the second end 75b of the second link 75. A fork 45 is connected to each of the tip portions 70b of the pair of arms 70. Therefore, the fork 45 is pivotably connected to the second link 75 that forms the tip portion 70b of the arm 70.

[0129] In the second embodiment, the operator operates the input unit 57 to input the height of the pallet hole 101a as a position command value. The height of the pallet hole 101a is the height to which the fork 45 can be inserted. The height of the pallet hole 101a changes depending on the surface on which the pallet 101 is placed. The surface on which the pallet 101 is placed is the floor, the top surface of a shelf, the top surface of a truck bed, etc.

[0130] The control device 50 includes an arm control unit (not shown). The arm control unit is connected to a first joint motor 71a, a second joint motor 72a, a first encoder 71b, and a second encoder 72b.

[0131] The input unit 57 outputs the input arm command value to the arm control unit. The arm command value is a command value for commanding the angle of the arm 70. The arm control unit controls the drive of the first joint motor 71a and the second joint motor 72a according to the arm command value, thereby controlling the angle of the arm 70 by rotating the first joint 71 and the second joint 72. Specifically, the arm control unit controls the angle of the arm 70 to position the fork 45 at the loading / unloading position P1 and the retracted position P2. Therefore, the first joint motor 71a and the second joint motor 72a are moving devices for moving the fork 45.

[0132] The arm control unit acquires detection signals detected by the first encoder 71b and the second encoder 72b. Based on the acquired detection signals, the arm control unit detects the rotation angles of the first joint motor 71a and the second joint motor 72a. The arm control unit controls the driving of the first joint motor 71a and the second joint motor 72a based on the height of the pallet hole 101a. As a result, the angle of the pair of arms 70 changes according to the height of the pallet hole 101a.

[0133] When the arm control unit adjusts the angle of the arm 70 and the fork 45 is positioned at the loading / unloading position P1, the center of gravity G of the vehicle body 11 moves forward of the reference line M. In this case, the attitude control unit 51 moves the center of gravity G in the longitudinal direction X according to the shape of the arm 70 and the position of the fork 45. In other words, the attitude control unit 51 moves the center of gravity G by performing the same loading / unloading process as in the first embodiment.

[0134] Then, as shown in Figure 11, the cargo handling mobile body 10 inverts in a rearward-tilted position T3 when in the cargo handling state. At this time, the auxiliary member control unit 56 performs the same cargo handling process as in the first embodiment, moving the legs 64 to bring the auxiliary wheels 65 into contact with the running surface F. In other words, the auxiliary member control unit 56 sets the form of the auxiliary member 61 to auxiliary form H1.

[0135] Subsequently, in the cargo handling mobile body 10, the arm control unit controls the shape of the arm 70 to position the fork 45 in the retracted position P2, as shown in Figure 12. Although not shown, in synchronization with the arm control unit moving the fork 45 from the cargo handling position P1 to the retracted position P2, the auxiliary member control unit 56 changes the position of the legs 64 so that the vehicle body 11 is raised toward the side where the cargo handling was performed. As a result, in synchronization with the movement of the legs 64, the cargo handling mobile body 10 inverts in a rearward-tilted position T3.

[0136] Furthermore, before the cargo handling mobile body 10 travels, the auxiliary member control unit 56 performs the same processing as in the cargo handling process of the first embodiment, moving the auxiliary wheels 65 away from the travel surface F to change the configuration of the auxiliary member 61 to the non-auxiliary configuration H2. At this time, the distance of the auxiliary wheels 65 from the travel surface F is set to a desired value.

[0137] Therefore, according to the second embodiment, the same effects as (1-1) to (1-11) described in the first embodiment can be obtained. (Third Embodiment) Next, a third embodiment that embodies the cargo handling mobile body 10 will be described. Note that the third embodiment is a configuration in which the auxiliary members of the first embodiment have been changed, so a detailed explanation of the same parts will be omitted.

[0138] As shown in Figures 13 and 14, the cargo handling mobile body 10 is equipped with four auxiliary members 90. Two of the four auxiliary members 90 are provided on both sides in the left-right direction Y at the front of the machine base 12. In Figure 13, only one of the auxiliary members 90 is shown, but the other two of the four auxiliary members 90 are provided on both sides in the left-right direction Y at the rear of the machine base 12.

[0139] Each auxiliary member 90 includes a rod-shaped leg portion 91 connected to the machine base 12 on the vehicle body 11. Each auxiliary member 90 includes an auxiliary wheel 92, which is a contact portion that contacts the running surface F. Therefore, each auxiliary member 90 includes an auxiliary wheel 92 that contacts the running surface F on which the cargo handling mobile body 10 travels, and a leg portion 91 connected to the vehicle body 11 that supports the vehicle body 11 by bringing the auxiliary wheel 92 into contact with the running surface F. The auxiliary wheel 92 is rotatably supported at the lower end of the leg portion 91. The auxiliary wheel 92 rotates in contact with the running surface F.

[0140] The legs 91 and auxiliary wheels 92 are fixed in their relative positions to the vehicle body 11. When the vehicle body 11 is in a reference position T1, both the front and rear auxiliary wheels 92 are spaced apart from the running surface F. When the vehicle body 11 is in a reference position T1, the distance at which the auxiliary wheels 92 are spaced apart from the running surface F is set such that when the vehicle body 11 tilts in either the front-rear direction X, the auxiliary wheels 92 contact the running surface F and prevent the vehicle body 11 from tipping over.

[0141] As shown in Figure 16, the cargo handling mobile vehicle 10 swings its body 11 under the control of the attitude control unit 51, changing the attitude of the body 11 from a standard attitude T1 to a forward-tilted attitude T2 or a backward-tilted attitude T3. This allows the auxiliary member 90 on the tilted side of the body 11 to be configured as an auxiliary configuration H1, in which the auxiliary wheels 92 are in contact with the running surface F. In other words, the cargo handling mobile vehicle 10 can change the configuration of the auxiliary member 90 to an auxiliary configuration H1, in which the legs 91 support the body 11. The auxiliary member 90 configured as auxiliary configuration H1 is an auxiliary member 90 provided on the side of the body 11 opposite to the side where cargo handling is performed by the forks 45.

[0142] Furthermore, as shown in Figure 14, the cargo handling mobile vehicle 10 can change the configuration of the auxiliary member 90 relative to the running surface F from auxiliary configuration H1 to non-auxiliary configuration H2, in which the auxiliary wheels 93 do not come into contact with the running surface F, by bringing the posture of the vehicle body 11 closer to the reference posture T1 under the control of the posture control unit 51. The auxiliary member 90 in non-auxiliary configuration H2 is an auxiliary member 90 provided on the side of the vehicle body 11 opposite to the side on which cargo handling is performed by the forks 45.

[0143] The attitude control unit 51 functions as an attitude control unit that causes the vehicle body 11 to swing, thereby swinging the legs 91 and auxiliary wheels 92, and changing the configuration of the auxiliary member 90 to either auxiliary configuration H1 or non-auxiliary configuration H2.

[0144] <Operation of the cargo handling mobile body> Next, the operation of the cargo handling mobile body 10 in the third embodiment will be explained using Figure 15. Note that the same operations as in the first embodiment will not be explained.

[0145] As shown in Figure 13, the body 11 of the cargo handling mobile vehicle 10 is controlled to maintain a reference posture T1, and the position of the forks 45 in the longitudinal direction X and the rotational position are controlled to be the cargo handling position P1 and the reference position, respectively. The configuration of each auxiliary member 90 is set to the non-auxiliary configuration H2.

[0146] Now, as shown in Figure 14, the cargo handling mobile body 10 moves along the movement path using two wheels, the right drive wheel 31 and the left drive wheel 32, and the cargo handling mobile body 10 approaches the cargo picking position (step S301).

[0147] As the cargo handling mobile vehicle 10 approaches the loading position, the attitude control unit 51 synchronously drives the right wheel drive motor 22 and the left wheel drive motor 27 to move the center of gravity G behind the reference line M in order to set the vehicle body 11 to a rearward tilted position T3. After driving the right wheel drive motor 22 and the left wheel drive motor 27 for a certain period of time, the attitude control unit 51 stops driving the right wheel drive motor 22 and the left wheel drive motor 27. As a result, the center of gravity G of the cargo handling mobile vehicle 10 moves behind the reference line M, and the vehicle body 11 tilts backward as the center of gravity G moves.

[0148] Then, when the vehicle body 11 tilts backward, the auxiliary wheels 92 come into contact with the running surface F, as shown in Figure 16. In other words, the cargo handling mobile vehicle 10 changes the configuration of the auxiliary members 90 to auxiliary configuration H1 (step S302). As a result, the vehicle body 11 of the cargo handling mobile vehicle 10 is supported by the two auxiliary members 90 positioned on the tilted side of the vehicle body 11.

[0149] Next, the position control unit 52 controls the drive of the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the cargo handling mobile body 10 forward toward the loading position. As a result, the cargo handling mobile body 10 moves to the loading position on all four wheels (step S303). After that, the cargo handling mobile body 10 inserts a pair of forks 45 into the pallet holes 101a (step S304). Subsequently, the tilt control unit 54 of the cargo handling mobile body 10 drives the tilt motor 42 to support the load W on the upper surface 45a of the forks 45 via the pallet 101. In other words, the cargo handling mobile body 10 performs cargo handling using the forks 45 (step S305).

[0150] Next, the tilt control unit 54 drives the tilt motor 42 to move the pair of forks 45 to the reference position, while the fork control unit 55 controls the drive of the fork motor 46 to move the forks 45 to the retracted position P2. In other words, the cargo handling mobile body 10 moves the forks 45 to the retracted position P2 (step S306).

[0151] As a result, the load W approaches the vehicle body 11. Therefore, the moment due to the load of the load W becomes smaller than when the load W is in the loading / unloading position P1. In other words, the moment due to the weight of the vehicle body 11 becomes relatively larger than the moment due to the load of the load W. Also, compared to when the load W is in the loading / unloading position P1, the center of gravity G of the loading / unloading mobile body 10 approaches the reference line M, and the posture of the vehicle body 11 approaches the reference posture T1. However, the center of gravity G is located behind the reference line M, and the posture of the vehicle body 11 remains in the rearward tilt posture T3. Furthermore, contact of the auxiliary wheels 92 with the running surface F is maintained, and the rearward tilt posture T3 of the vehicle body 11 remains supported by the auxiliary member 90 of auxiliary configuration H1.

[0152] Next, the position control unit 52 controls the drive of the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the cargo handling mobile body 10 backward from the loading position. In other words, the cargo handling mobile body 10 moves backward on all four wheels until it is a certain distance away from the loading position (step S307).

[0153] Next, the cargo handling mobile body 10 performs movement processing to move to the unloading position. The attitude control unit 51 drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to bring the center of gravity G closer to the reference line M. As a result, the configuration of the auxiliary member 90 becomes the non-auxiliary configuration H2, with the auxiliary wheels 92 separated from the running surface F. In other words, the cargo handling mobile body 10 changes the configuration of the auxiliary member 90 to the non-auxiliary configuration H2 (step S308). As a result, the cargo handling mobile body 10 stands upright on two wheels.

[0154] Subsequently, the position control unit 52 drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to move the vehicle body 11. In other words, the cargo handling mobile body 10 moves to the unloading position on two wheels (step S309). At this time, the vehicle body 11 moves while accelerating in a rearward-tilted posture T3. Based on the detection signal from the measurement unit 51a, the posture control unit 51 drives the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to adjust the position of the center of gravity G in the longitudinal direction X. Specifically, as the acceleration of the cargo handling mobile body 10 increases, the posture control unit 51 moves the center of gravity G to the rear and increases the tilt angle θ. Through this movement processing, the cargo handling mobile body 10 moves while maintaining an inverted state in a rearward-tilted posture T3. Subsequently, the cargo handling mobile body 10 reduces its movement speed so that it can come to a stop at the unloading position. As the movement speed of the cargo handling mobile body 10 decreases, the attitude control unit 51 reduces the inclination angle θ of the vehicle body 11, bringing the attitude of the vehicle body 11 closer to the reference attitude T1. Then, the cargo handling mobile body 10 arrives at the unloading position.

[0155] Accordingly, according to the third embodiment, in addition to the same effects as (1-1) to (1-11) described in the first embodiment, the following effects can be obtained. (3-1) The attitude control unit 51 controls the right wheel drive motor 22 of the right wheel drive unit 21 and the left wheel drive motor 27 of the left wheel drive unit 25 to swing the vehicle body 11 and change the mode of the auxiliary member 90 to either auxiliary mode H1 or non-auxiliary mode H2. When the mode of the auxiliary member 90 is auxiliary mode H1, the auxiliary wheels 92 are in contact with the running surface F. As a result, the vehicle body 11 can be supported by the auxiliary member 90, so that the cargo handling mobile body 10 can move the forks 45 from the cargo handling position P1 to the retracted position P2 in a stable state.

[0156] Furthermore, during cargo handling of the cargo handling mobile vehicle 10, the attitude control unit 51 controls the right wheel drive motor 22 and the left wheel drive motor 27 to bring the auxiliary wheels 92 into contact with the running surface F, thereby changing the configuration of the auxiliary member 90 to auxiliary configuration H1. This allows for more stable cargo handling compared to the case where cargo handling is performed by inverting the vehicle body 11 using only the left and right pair of drive wheels 31 and 32. As a result, the cargo handling mobile vehicle 10 can perform cargo handling stably and the vehicle body 11 can be made lighter.

[0157] (3-2) The attitude control unit 51 of the cargo handling mobile body 10 swings the legs 91 and auxiliary wheels 92 by swinging the vehicle body 11, thereby changing the configuration of the auxiliary member 90 to auxiliary configuration H1. As a result, the cargo handling mobile body 10 can change the configuration of the auxiliary member 90 to auxiliary configuration H1 by controlling the drive of the right wheel drive motor 22 and the left wheel drive motor 27, thus simplifying the structure of the auxiliary member 90.

[0158] (3-3) The cargo handling mobile body 10 moves to the loading position on four wheels and also moves backward from the loading position. For example, compared to the case where the cargo handling mobile body 10 approaches and moves away from the loading position on two wheels, the cargo handling mobile body 10 can approach and move away from the loading position in a stable state.

[0159] [Examples of Modifications] The above multiple embodiments can be implemented with the following modifications. The above multiple embodiments and the following examples of modifications can be combined with each other to the extent that they do not contradict each other technically.

[0160] ○In the cargo handling mobile body 10 of the first and second embodiments, the relative positions of the legs 64 and auxiliary wheels 65 with respect to the vehicle body 11 are fixed without driving the auxiliary member motor 66 in the auxiliary member 61. Then, under the control of the attitude control unit 51, the legs 64 and auxiliary wheels 65 may be swung together with the swinging of the vehicle body 11, so that the configuration of the auxiliary member 61 can be either auxiliary configuration H1 or non-auxiliary configuration H2.

[0161] ○In the third embodiment, the cargo handling mobile body 10 moves the forks 45 from the cargo handling position P1 to the retraction position P2 while the auxiliary member 90 is in auxiliary mode H1, and then the attitude control unit 51 swings the vehicle body 11 to change the auxiliary member 90 from auxiliary mode H1 to non-auxiliary mode H2. Then, the cargo handling mobile body 10 may move backward from the cargo picking position on two wheels without performing the operation of step S307, and move to the cargo unloading position on two wheels.

[0162] ○In the first and second embodiments, when the cargo handling mobile body 10 is traveling with the load W supported on the forks 45 in the retracted position P2, the distance at which the auxiliary wheels 65 are separated from the running surface F may be changed as appropriate. That is, the distance at which the auxiliary wheels 65 are separated from the running surface F may be a distance at which the auxiliary wheels 65 do not come into contact with the running surface F when the vehicle body 11 tilts due to the stopping of rotation of the drive wheels 31 and 32. In the third embodiment, when the cargo handling mobile body 10 is traveling with the load W supported on the forks 45 in the retracted position P2, the distance at which the vehicle body 11 is swung to separate the auxiliary wheels 92 from the running surface F may be changed as appropriate. That is, the distance at which the auxiliary wheels 92 are separated from the running surface F may be a distance at which the auxiliary wheels 92 do not come into contact with the running surface F when the vehicle body 11 tilts due to the stopping of rotation of the drive wheels 31 and 32.

[0163] ○In the first and second embodiments, the cargo handling mobile 10 does not need to have its auxiliary wheels 65 in contact with the running surface F at a position further away from the load W than the position where the load is picked up or unloaded. Also, in the third embodiment, the cargo handling mobile 10 does not need to have its auxiliary wheels 92 in contact with the running surface F at a position further away from the load W than the position where the load is picked up or unloaded. In this case, the cargo handling mobile 10 travels on two wheels to the position where the load is picked up or unloaded.

[0164] ○In the first and second embodiments, after the forks 45 supporting the load W are moved from the loading / unloading position P1 to the retracted position P2, the auxiliary member control unit 56 may change the position of the legs 64 so that the vehicle body 11 is raised toward the side where the loading / unloading took place.

[0165] ○In the first and second embodiments, before the cargo handling mobile body 10 travels with the load W supported by the forks 45 in the retracted position P2, the attitude control unit 51 may tilt the vehicle body 11 in a direction that straightens the vehicle body 11 which has been tilted to the opposite side from the side on which the cargo handling was performed, and then the auxiliary member control unit 56 may straighten the vehicle body 11 with the legs 64.

[0166] ○In the third embodiment, when the auxiliary member 90 is set to auxiliary mode H1, the attitude control unit 51 pre-determines the angle at which the vehicle body 11 is tilted. Then, when the auxiliary member 90 is set to auxiliary mode H1, the vehicle body 11 is swung at the pre-determined angle so that the auxiliary wheels 92 come into contact with the running surface F when the swinging of the vehicle body 11 is stopped. With this configuration, the impact generated when the auxiliary wheels 92 come into contact with the running surface F can be reduced.

[0167] As shown in Figure 17, in the cargo handling device 40, the forks 45 may be configured to handle loads either in front of or behind the vehicle body 11, with respect to the vehicle body 11. The forks 45 slide forward and backward relative to the vehicle body 11. In this case, the forks 45 are thinner at both ends in the longitudinal direction, and can be inserted into the pallet holes 101a at both ends in the longitudinal direction. The cargo handling mobile body 10 is also equipped with auxiliary members 61 on both the front and rear surfaces of the machine base 12. In this configuration, when handling loads at the rear of the vehicle body 11, the fork control unit 55 controls the drive of the fork motor 46 to move the forks 45 to the rear of the vehicle body 11 and position them at the cargo handling position P1. At this time, the auxiliary member control unit 56 controls the auxiliary member 61 located on the opposite side of the fork 45 at the loading / unloading position P1 relative to the vehicle body 11, moving the leg portion 64 toward the running surface F and bringing the auxiliary wheel 65 into contact with the running surface F, thereby changing the configuration of the auxiliary member 90 to auxiliary configuration H1.

[0168] As shown in Figure 18, the auxiliary member 80 may be provided on at least one side of the machine base 12 in the left-right direction Y. The auxiliary member 80 comprises a leg support portion 83 fixed to the side surface of the machine base 12, and a leg portion 84 that is movably supported with respect to the leg support portion 83 and includes an auxiliary wheel 85.

[0169] The leg support portion 83 is cylindrical with an axis extending in the front-rear direction X. The leg portion 84 comprises a semicircular arm portion 84a and wheel support portions 84b provided at both ends of the arm portion 84a. The auxiliary wheel 85 is rotatably supported by the wheel support portion 84b.

[0170] In this configuration, when handling a load on the front or rear side of the vehicle body 11, the fork control unit 55 controls the drive of the fork motor 46 to move the fork 45 to the front or rear side of the vehicle body 11 and position it at the load handling position P1. At this time, the auxiliary member control unit 56 changes the position of the legs 84 relative to the vehicle body 11 so that the auxiliary wheels 85 located on the opposite side of the vehicle body 11 from the fork 45 at the load handling position P1 are closer to the running surface F, and also brings the auxiliary wheels 85 into contact with the running surface F, thereby changing the configuration of the auxiliary member 90 to auxiliary configuration H1.

[0171] ○In the first and second embodiments, the auxiliary member 61 does not need to have an auxiliary wheel 65. Also, in the third embodiment, the auxiliary member 90 does not need to have an auxiliary wheel 92. In this case, the auxiliary members 61 and 90 consist only of legs 64 and 91. The contact points of the auxiliary members 61 and 90 are the lower end surfaces of the legs 64 and 91.

[0172] ○In the first and second embodiments, if the running surface F is stepped, the auxiliary member control unit 56 may change the position of the leg portion 64 relative to the vehicle body 11 in steps, thereby bringing the auxiliary wheel 65 into contact with the running surface F in steps.

[0173] ○The cargo handling device 40 may be equipped with a tilt motor 42 and load sensors positioned on the bars 44. These load sensors make contact with the load W at the same time as or before the load W is supported by the forks 45. The load sensors are also signal-connected to the attitude control unit 51. At the same time as or before the load W is supported by the forks 45, the load W may be brought into contact with the load sensors, causing the load sensors to output a load signal related to the weight of the load W. The load signal output by the load sensors is acquired by the attitude control unit 51. The attitude control unit 51 may then move the center of gravity G of the cargo handling mobile body 10 in accordance with the load signal. In this case, the control device 50 does not need to be equipped with a communication unit 58.

[0174] ○When the weight of the load W repeatedly transported by the cargo handling mobile body 10 is the same, the moment generated when the load W is supported by the forks 45 is approximately constant while it is being repeatedly transported. In this case, the moment generated can be derived from the uniquely determined weight of the load W, and the drive amounts of each drive motor 22, 27 for moving the center of gravity G can be derived and pre-inputted to the attitude control unit 51. In this case, the control device 50 does not need to be equipped with a communication unit 58.

[0175] ○If the weight of the loads W repeatedly transported by the cargo handling mobile body 10 falls within a certain range, the average weight of those loads W can be calculated. Then, the moment generated can be calculated from the average value, and the drive amount of each drive motor 22, 27 for moving the center of gravity G can be calculated and pre-inputted to the attitude control unit 51. In this case, the control device 50 does not need to be equipped with a communication unit 58.

[0176] ○In the second embodiment, the cargo handling device 40 of the cargo handling mobile body 10 may be equipped with only one arm 70. ○In the second embodiment, the number of links and joints constituting the arm 70 may be changed as appropriate, as long as the fork 45 can be moved to the cargo handling position P1 or the retracted position P2.

[0177] ○In each configuration, the housing 35 may be omitted. ○The right drive wheel 31 and the left drive wheel 32 may be driven by a single drive motor. In this case, a cover is installed on the first main surface 121 of the machine base 12, and the drive motor and encoder are housed in that cover. Thus, the vehicle body 11 is equipped with a single drive unit.

[0178] ○The storage space S of the housing 35 may contain heavy objects other than the battery 33 and the housing 35. ○The support member of the cargo handling device 40 may be a suction device for picking up the load W or a hand device for gripping the load W instead of the forks 45. Alternatively, the support member may be an endless belt instead of the forks 45. In this case, the cargo handling device 40 includes a rotating device for rotating the belt. By rotating the belt with the rotating device, the load W supported by the belt may be moved from the cargo handling position P1 to the retraction position P2. In short, as long as the load W can be moved to the cargo handling position P1 or the retraction position P2, the configuration of the support member in the cargo handling device 40 can be changed as appropriate.

[0179] ○In the first and second embodiments, the auxiliary member 61 may be a hydraulic cylinder. In this case, the leg portion 64 is formed by the rod of the hydraulic cylinder. The position of the leg portion 64, which is the rod, is changed relative to the cylinder body by supplying and discharging hydraulic pressure to and from the hydraulic cylinder.

[0180] ○The load W may be directly supported by the fork 45 without going through the pallet 101. ○The drive unit may be an actuator other than a motor.

[0181] F...running surface, G...center of gravity, L...axis that is the pivot center, P1...loading position, P2...retracted position, X...forward and backward direction, 10...mobile body for loading and unloading, 11...vehicle body, 21...right wheel drive unit, 23...right axle, 25...left wheel drive unit, 26...left axle, 31...right drive wheel, 32...left drive wheel, 40...loading device, 45...fork which is a support member, 46...motor fork which is a moving device, 51...attitude control unit which is an attitude control unit, 55...fork control unit which is a support member control unit, 56...auxiliary member control unit which is an attitude control unit, 61, 80, 90...auxiliary members, 64, 84, 91...legs, 65, 85, 92...auxiliary wheels which are contact parts, 66...auxiliary member motor which is a displacement device, 71a...first joint motor which is a moving device, 72a...second joint motor which is a moving device.

Claims

1. An inverted wheel type cargo handling mobile body comprising: a pair of left and right drive wheels; a drive unit configured to drive the pair of left and right drive wheels, and a body configured to pivot around an axis coaxial with the axles of the pair of left and right drive wheels by the drive unit; a cargo handling device supported by the body, the cargo handling device comprising a support member for supporting a load and a moving device configured to move the support member, the support member configured to be displaced between a cargo handling position in which the load is handled by the moving device and a retracted position in the front-rear direction that is closer to the body than the cargo handling position; and an auxiliary member comprising a leg portion including a contact portion that contacts the running surface on which the cargo handling mobile body travels, the leg portion being connected to the body and configured to support the body by contacting the contact portion with the running surface, the auxiliary member being provided in the front-rear direction on the side opposite to the side on which cargo handling is performed by the support member, with respect to the body. A mobile cargo handling device comprising: an attitude control unit configured to control the attitude of the vehicle body by oscillating the vehicle body with the aforementioned axis as the pivot point; a support member control unit configured to control the moving device so as to position the support member at the cargo handling position or the retraction position; and an attitude control unit configured to set the configuration of the auxiliary member with respect to the running surface to either an auxiliary configuration in which the contact portion is in contact with the running surface and the vehicle body is supported by the leg portion, or a non-auxiliary configuration in which the contact portion is not in contact with the running surface.

2. The cargo handling mobile body according to claim 1, wherein the contact portion is an auxiliary wheel that rotates in contact with the running surface.

3. The cargo handling mobile body according to claim 1 or 2, wherein the auxiliary member further comprises a displacement device configured to change the position of the leg portion relative to the vehicle body, and the cargo handling mobile body further comprises an auxiliary member control unit configured to control the displacement device to change the configuration of the auxiliary member to either the auxiliary configuration or the non-auxiliary configuration, and the configuration control unit is the auxiliary member control unit.

4. The mobile cargo handling vehicle according to claim 1 or 2, wherein the legs and contact portion are provided on the vehicle body with their relative positions to the vehicle body fixed, the configuration control unit includes the attitude control unit, and the attitude control unit is configured to swing the legs and contact portion by swinging the vehicle body, thereby changing the configuration of the auxiliary member to either the auxiliary configuration or the non-auxiliary configuration.

5. The cargo handling mobile body according to claim 1 or 2, wherein when the cargo handling mobile body is in motion, the mode control unit is configured to change the mode of the auxiliary member to the auxiliary mode.

6. The cargo handling mobile body according to claim 1 or claim 2, wherein the auxiliary members are provided on the front and rear sides of the vehicle body, and the support members support the load in front of or behind the vehicle body.

7. A method for operating an inverted wheel type cargo handling mobile body, wherein the cargo handling mobile body comprises a pair of left and right drive wheels, a drive unit configured to drive the pair of left and right drive wheels, and a body configured to pivot on an axis coaxial with the axles of the pair of left and right drive wheels by the drive of the drive unit, and a cargo handling device supported by the body, wherein the cargo handling device comprises a support member for supporting a load and a moving device configured to move the support member, and the support member is configured to be displaced between a cargo handling position in which the load is handled by the moving device and a retracted position in the front-rear direction that is closer to the body than the cargo handling position, An auxiliary member comprising a leg portion including a contact portion that contacts the running surface on which the cargo handling mobile body travels, and a displacement device configured to change the position of the leg portion relative to the vehicle body, wherein the leg portion is connected to the vehicle body and configured to support the vehicle body by contacting the contact portion with the running surface, and the auxiliary member is provided in the front-rear direction on the side of the vehicle body opposite to the side on which cargo handling is performed by the support member, an attitude control unit configured to control the attitude of the vehicle body by swinging the vehicle body about the axis as the pivot point, a support member control unit configured to control the moving device to position the support member at the cargo handling position or the retraction position, and an attitude control unit configured to control the displacement device to change the orientation of the auxiliary member relative to the running surface to either an auxiliary orientation in which the contact portion contacts the running surface and supports the vehicle body by the leg portion, or a non-auxiliary orientation in which the contact portion does not contact the running surface. During cargo handling by the cargo handling device, the support member control unit is configured to move the support member supporting the load from the cargo handling position to the retraction position; the attitude control unit is configured to tilt the vehicle body in the front-rear direction toward the side opposite to the side on which cargo handling is performed by the support member; and the configuration control unit is configured to control the displacement device to change the position of the leg portion in a direction that brings the contact portion into contact with the running surface in order to change the configuration of the auxiliary member to the auxiliary configuration.A method for operating a cargo handling mobile body, wherein, when the cargo handling mobile body is traveling with the load supported on the support member in the retracted position, the attitude control unit is configured to tilt the vehicle body toward the direction of travel of the cargo handling mobile body, and the configuration control unit is configured to control the displacement device to change the position of the leg portion in a direction that separates the contact portion from the travel surface in order to change the configuration of the auxiliary member to the non-auxiliary configuration.

8. The method for operating a cargo handling mobile body according to claim 7, wherein, before the cargo handling mobile body travels with the load supported on the support member in the retracted position, the attitude control unit is configured to tilt the vehicle body in a direction that straightens the vehicle body which is tilted to the side opposite to the side on which the cargo handling was performed, and in synchronization with the tilting of the vehicle body by the attitude control unit, the attitude control unit is configured to control the displacement device to change the position of the legs in a direction that straightens the vehicle body by the legs.

9. The method for operating a mobile cargo handling body according to claim 8, wherein, during cargo handling by the cargo handling device, the mode control unit is configured to control the displacement device to raise the vehicle body toward the side on which the cargo handling was performed, thereby changing the position of the legs in synchronization with the change of the support member supporting the load from the cargo handling position to the retraction position.

10. The method for operating a cargo handling mobile body according to claim 7 or 8, wherein, when the cargo handling mobile body is at a position further from the load than the position where the cargo handling is performed, the mode control unit controls the displacement device to change the position of the leg portion relative to the vehicle body in order to change the mode of the auxiliary member to the auxiliary mode, thereby bringing the contact portion into contact with the running surface.

11. The method for operating a cargo handling mobile body according to claim 7 or claim 8, wherein, when the cargo handling mobile body is traveling with the load supported on the support member in the retracted position, the distance by which the mode control unit controls the displacement device to separate the contact portion from the running surface is such that when the vehicle body tilts due to the stopping of the rotation of the drive wheels, the contact portion contacts the running surface to prevent the vehicle body from tipping over.

12. A method for controlling an inverted wheel type cargo handling mobile body, wherein the cargo handling mobile body comprises a pair of left and right drive wheels, a drive unit configured to drive the pair of left and right drive wheels, and a body configured to pivot around an axis coaxial with the axles of the pair of left and right drive wheels by the drive unit, and a cargo handling device supported by the body, wherein the cargo handling device comprises a support member for supporting a load and a moving device configured to move the support member, and the support member is configured to be displaced between a cargo handling position in which the load is handled by the moving device and a retracted position in the front-rear direction that is closer to the body than the cargo handling position, An auxiliary member comprising a leg portion including a contact portion that contacts the running surface on which the cargo handling mobile body travels, and a displacement device configured to change the position of the leg portion relative to the vehicle body, wherein the leg portion is connected to the vehicle body and configured to support the vehicle body by contacting the contact portion with the running surface, and the auxiliary member is provided in the front-rear direction on the side of the vehicle body opposite to the side on which cargo handling is performed by the support member, wherein the configuration of the auxiliary member relative to the running surface includes an auxiliary configuration in which the contact portion contacts the running surface and the vehicle body is supported by the leg portion, and a non-auxiliary configuration in which the contact portion does not contact the running surface, and the control method is A method for controlling a cargo handling mobile body, comprising: positioning the support member supporting the load from the cargo handling position to the retraction position during cargo handling by the cargo handling device; tilting the vehicle body in the front-rear direction toward the side opposite to the side on which cargo handling is performed by the support member; controlling the displacement device to change the position of the leg portion in a direction that brings the contact portion into contact with the running surface in order to change the configuration of the auxiliary member to the auxiliary configuration; and tilting the vehicle body toward the direction of travel of the cargo handling mobile body when the cargo handling mobile body is traveling with the load supported by the support member in the retraction position; and controlling the displacement device to change the position of the leg portion in a direction that moves the contact portion away from the running surface in order to change the configuration of the auxiliary member to the non-auxiliary configuration.

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