Control method for cargo-handling mobile body

Abstract

A control method for a cargo-handling mobile body (10) involves: a posture control unit causing a cargo-handling platform (100) to support a vehicle body (11) in a tilted posture by causing the vehicle body (11) to rock; and a conveyor control unit driving a conveyor (45) so as to perform cargo handling in a state in which the cargo-handling platform (100) supports the vehicle body (11).

Description

Control method for a load-carrying mobile body

[0001] The present invention relates to a control method for a 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 a two-wheeled inverted wheel type. The load-carrying mobile body includes a pair of left and right drive wheels, a vehicle body that can swing 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.

[0003] Further, the load-carrying mobile body includes a drive unit that drives a pair of left and right drive wheels, and a control device that controls the drive unit. The control device includes an attitude control unit. The attitude control unit controls the attitude of the vehicle body by swinging the vehicle body in the front-rear direction by controlling the drive of the pair of left and right drive units. 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 in a state where the load is supported by the load-carrying device. At this time, the load-carrying mobile body utilizes the weight of the vehicle body itself as a balance weight to enable the load-carrying mobile body to be inverted.

[0004] Japanese Unexamined Patent Application Publication No. 2024-88228

[0005] However, in an inverted wheel type load-carrying mobile body, due to fluctuations in the center of gravity associated with supporting or unloading a load by the load-carrying device, the attitude of the vehicle body becomes unstable, and stable load-carrying cannot be performed.

[0006] A method for controlling a mobile cargo handling vehicle to solve the above problems is a method for controlling an inverted wheel type mobile cargo handling vehicle that performs cargo handling, wherein the mobile cargo handling vehicle comprises a pair of left and right drive wheels, a drive unit that drives the pair of left and right drive wheels, a vehicle body that swings in the front-rear direction about an axis coaxial with the axles of the pair of left and right drive wheels as a pivot point by the drive unit, a cargo handling device supported by the vehicle body that performs cargo handling on a load, a cargo handling device control unit that controls the drive of the cargo handling device, and a posture control unit that controls the drive of the drive unit to swing the vehicle body in the front-rear direction about the axis as a pivot point, wherein the posture control unit swings the vehicle body to support the vehicle body in an inclined position on a vehicle body support, and the cargo handling device control unit drives the cargo handling device to perform cargo handling while the vehicle body is supported on the vehicle body support.

[0007] According to this, in the control method for a cargo handling mobile vehicle, when the vehicle body is supported by a vehicle body support, a reaction force is generated on the vehicle body from the vehicle body support. Due to this reaction force, the vehicle body maintains a stable posture even while in an inclined position. Specifically, the cargo handling mobile vehicle has two points of contact: the drive wheels are in contact with the ground and the vehicle body is in contact with the vehicle body support. This makes the vehicle body's posture more stable compared to a state where only the drive wheels are in contact with the ground. Furthermore, the control method for the cargo handling mobile vehicle performs cargo handling using the cargo handling device while the vehicle body's posture is stabilized by these two points of contact. Therefore, even in situations where the center of gravity fluctuates due to cargo handling, it becomes unnecessary to stabilize the vehicle body's posture by swaying it using the posture control unit. As a result, the cargo handling mobile vehicle can perform cargo handling stably according to this control method.

[0008] Regarding the control method for a cargo handling mobile body, the cargo handling mobile body comprises a restricting unit that restricts the rotation of the left and right pair of drive wheels, and a rotation restricting unit that controls the driving of the restricting unit, wherein, with the vehicle body supported by the vehicle body support, the rotation restricting unit drives the restricting unit to restrict the rotation of the left and right pair of drive wheels.

[0009] According to this, the rotation of the drive wheels is restricted by the restricting part, so when loading and unloading is performed with the vehicle body supported by the vehicle body support, the rotation of the drive wheels can be restricted. As a result, when loading and unloading is performed with the vehicle body supported by the vehicle body support, that is, in a two-point contact state, even if a shift in the center of gravity occurs due to loading and unloading, the movement of the vehicle body caused by the rotation of the drive wheels is suppressed, so that the loading and unloading vehicle can perform loading and unloading stably.

[0010] Regarding the control method for a cargo handling mobile body, the cargo handling mobile body can assume a forward-tilting posture in which the upper end of the vehicle body is positioned in front of the lower end of the vehicle body, and the posture control unit may swing the vehicle body into the forward-tilting posture and support the vehicle body on the vehicle body support.

[0011] According to this, for example, compared to a case where cargo handling is performed in a rearward-tilting position with the upper end of the vehicle body positioned behind the lower end of the vehicle body, the cargo handling mobile vehicle can perform cargo handling in a stable vehicle body position.

[0012] Regarding the control method for a cargo handling mobile body, the cargo handling device control unit may drive the cargo handling device to displace the load from the load picking position to a position different from the load picking position and to a retraction position on the vehicle body side, and the attitude control unit may drive the drive unit to maintain the inverted position of the vehicle body in conjunction with the cargo handling device control unit driving the cargo handling device to displace the load from the load picking position to the retraction position.

[0013] According to this, as the load is moved from the loading position to the retraction position, the center of gravity shifts from the loading position to the retraction position. As a result, while the vehicle body remains supported by the vehicle body support, the pair of drive wheels on both sides rotate in the forward direction, causing the vehicle body to swing in the direction of natural upright positioning. Furthermore, as the load moves from the loading position to the retraction position, the pair of drive wheels on both sides rotate in the reverse direction. In conjunction with this, the attitude control unit drives the drive unit to maintain the inverted position of the vehicle body, causing the vehicle body to move away from the vehicle body support while maintaining its inverted state. As a result, after loading and unloading, the loading and unloading vehicle can be quickly moved toward a location away from the vehicle body support.

[0014] Regarding the control method for a mobile cargo handling vehicle, it is preferable that the attitude control unit supports the vehicle body on the vehicle body support before the cargo handling device control unit drives the cargo handling device to perform cargo handling.

[0015] According to this, the cargo handling mobile vehicle can start cargo handling in a stable position with two-point contact: the drive wheels in contact with the ground and the vehicle body in contact with the vehicle body support. Regarding the control method of the cargo handling mobile vehicle, the cargo handling mobile vehicle is equipped with a reaction force estimation unit that estimates the reaction force that the vehicle body supported by the vehicle body support receives from the vehicle body support, and the attitude control unit may swing the vehicle body based on the reaction force information obtained from the reaction force estimation unit.

[0016] According to this, the attitude control unit can accurately support the vehicle body on the vehicle body bearing by obtaining information related to reaction forces from the reaction force estimation unit.

[0017] This invention enables stable cargo handling.

[0018] Figure 1 is a side view showing a cargo handling mobile body and cargo handling platform of the first embodiment. Figure 2 is a diagram showing the cargo handling mobile body. Figure 3 is a perspective view showing the cargo handling mobile body. Figure 4 is a side view showing the cargo handling mobile body in a forward-tilting position and a backward-tilting position. Figure 5 is a block diagram showing the control device. Figure 6 is a side view showing a cargo handling mobile body with its body supported on a cargo handling platform. Figure 7 is a side view showing a cargo handling mobile body with a load pulled in from the loading position. Figure 8 is a side view showing a cargo handling mobile body with a load displaced to the retraction position. Figure 9 is a diagram showing a cargo handling mobile body of the second embodiment. Figure 10 is a side view of a cargo handling mobile body with its body supported on a cargo handling platform. Figure 11 is a side view of a cargo handling mobile body with a load displaced to the retraction position. Figure 12 is a side view showing a cargo handling mobile body equipped with a weight on the arm. Figure 13 is a side view of a cargo handling mobile body with its center of gravity changed. Figure 14 is a side view showing a cargo handling vehicle with the rotation of the drive wheels restricted by a regulating mechanism. Figure 15 is a side view showing a cargo handling vehicle supported by a vehicle support located at the rear of the vehicle body.

[0019] [First Embodiment] The first embodiment of the cargo handling mobile body will be described below. <Overall view of the cargo handling mobile body> As shown in Figure 1, the cargo handling mobile body 10 is an inverted wheel type that performs cargo handling. The cargo handling mobile body 10 approaches the cargo handling platform 100 to perform cargo handling. The cargo handling platform 100 is a platform on which the cargo W transported by the cargo handling mobile body 10 is placed. On the mounting surface 100a of the cargo handling platform 100, although only one is shown in Figure 1, a pallet 101 is placed via a pair of pallet mounting platforms 102. The cargo W consists of the pallet 101 and the cargo Wa placed on the pallet 101. Note that the cargo W may consist only of the cargo Wa, without including the pallet 101.

[0020] As shown in Figures 1 to 3, the cargo handling mobile vehicle 10 comprises a vehicle body 11, a pair of drive wheels (right drive wheel 31 and left drive wheel 32), a drive unit (right wheel drive unit 21 and left wheel drive unit 25), a cargo handling device 40, and a control device 50. The cargo handling device 40 performs cargo handling on the cargo W. The control device 50 controls the drive of the cargo handling mobile vehicle 10. The cargo handling device 40 and the control device 50 will be described in detail later.

[0021] In the following description, front, rear, left, and right refer to the front, rear, left, and right 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 cargo handling mobile vehicle 10 has a front surface 11a on one side of the vehicle body 11 in the front-rear direction X, and a rear surface 11b on the other side. The front surface 11a and the rear surface 11b are located opposite each other in the front-rear direction X. The cargo handling mobile vehicle 10 moves forward when moving in the direction facing the front surface 11a, and moves backward when moving in the direction facing the rear surface 11b. The left-right direction Y is the width 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 surface 11a side. The vertical direction Z is the height direction of the cargo handling mobile vehicle 10.

[0022] <Vehicle Body> The vehicle body 11 comprises a machine base 12, a housing 35, and a secondary battery 60. The vehicle body 11 is also equipped with a cargo handling device 40 and a control device 50. 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.

[0023] The housing 35 is positioned on the second main surface 122. The housing 35 is box-shaped. The top plate of the housing 35 is the mounting surface 351 for the cargo handling device 40. The front surface 11a of the vehicle body 11 is one of the four sides of the housing 35, and the rear surface 11b is the opposite side of the housing 35 from the front surface 11a. The control device 50 and the secondary battery 60 are housed inside the housing 35.

[0024] <Right-wheel drive unit and left-wheel drive unit> The right-wheel drive unit 21 drives the right drive wheel 31, and the left-wheel drive unit 25 drives the left drive wheel 32. Therefore, the right-wheel drive unit 21 and the left-wheel drive unit 25 drive a pair of left and right drive wheels 31 and 32. 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 housed inside the right cover 29a. The right axle 23 is connected to the rotation shaft of the right-wheel drive motor 22. The right axle 23 rotates by the drive of the right-wheel drive motor 22. The right axle 23 passes through the right cover 29a and protrudes to the outside of the right cover 29a. The right drive wheel 31 is fixed to a projection 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.

[0025] 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 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 protrusion from the left cover 29b on the left axle 26. 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.

[0026] <Right drive wheel and left drive wheel> 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 right drive wheel 31 and the left drive wheel 32 rotate in contact with the running surface F. Therefore, the cargo handling mobile body 10 is in contact with the running surface F by the right drive wheel 31 and the left drive wheel 32.

[0027] 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 left and right drive wheels 31 and 32 lie on the same axis. The vehicle body 11 swings around axis L as its pivot point by the drive of the right wheel drive unit 21 and the left wheel drive unit 25. The right wheel drive unit 21 and the left wheel drive unit 25, the cargo handling device 40, and the control device 50 are driven by power supplied from the secondary battery 60.

[0028] <Cargo Handling Device> The cargo handling device 40 is installed on the mounting surface 351 of the vehicle body 11 and is supported by the vehicle body 11. The cargo handling device 40 comprises a conveyor motor 42, a conveyor encoder 43, two conveyors 45, two connecting members 46, a tilt motor 71, a support shaft 71a, and a tilt encoder 72. The tilt motor 71, the support shaft 71a, and the tilt encoder 72 constitute the tilt device 70 included in the cargo handling device 40.

[0029] The conveyor motor 42 is supported by the tilt motor 71 via a support shaft 71a. The conveyor encoder 43 detects the rotation angle as the amount of rotation of the conveyor motor 42. The rotation shaft 44 of the conveyor motor 42 extends from the conveyor motor 42 in the left-right direction Y.

[0030] Each conveyor 45 comprises one drive roller 45a, a plurality of driven rollers 45b, a conveyor belt 45c, and a roller support member 45d. In each conveyor 45, the drive roller 45a and the plurality of driven rollers 45b are aligned in the front-rear direction X. The drive roller 45a and the plurality of driven rollers 45b are held in this aligned state in the front-rear direction X by the roller support member 45d. The endless conveyor belt 45c is wrapped around the drive roller 45a and the plurality of driven rollers 45b. The roller support member 45d is located on the conveyor motor 42 side of each conveyor 45, on the left-right direction Y side. The rotation shaft 44 of the conveyor motor 42 and the roller shaft 47 of each driven roller 45b are rotatably supported by the roller support member 45d. The rotating shaft 44 of the conveyor motor 42 passes through the roller support member 45d and is integrated with the drive roller 45a, and the drive roller 45a rotates together with the rotating shaft 44 of the conveyor motor 42. The drive roller 45a is positioned in the center of the longitudinal direction of the conveyor belt 45c and causes the conveyor belt 45c to circumvent. Multiple driven rollers 45b support the conveyor belt 45c and assist in the circumduction of the conveyor belt 45c.

[0031] Each of the two connecting members 46 is positioned between each roller support member 45d and the conveyor motor 42 in the left-right direction Y. Each connecting member 46 connects each roller support member 45d to the conveyor motor 42. The connecting member 46 is cylindrical, and a rotating shaft 44 is inserted through the inside of the connecting member 46.

[0032] The conveyor 45 extends forward of the front surface 11a of the vehicle body 11 and backward of the rear surface 11b. Of the outer surface of the conveyor belt 45c, the surface located above the multiple driven rollers 45b and the drive rollers 45a, and facing upward, is designated as the support surface 451. The load W is supported by the support surface 451 of the conveyor belt 45c. As the conveyor belt 45c rotates, the load W is displaced from the front to the rear of the vehicle body 11 and from the rear to the front of the vehicle body 11.

[0033] The conveyor motor 42 circulates the conveyor belt 45c to displace the load W, supported on the support surface 451, from the load pick-up position FP to the retraction position BP. The load pick-up position FP is located on the support surface 451 at the front end of the conveyor 45. The load pick-up position FP is predetermined to be at a specific position in the longitudinal direction X of the conveyor 45. The load W at the load pick-up position FP is located in front of the vehicle body 11. The retraction position BP is located on the support surface 451 at the rear end of the conveyor 45. The retraction position BP is located at a different position from the load pick-up position FP, specifically at a predetermined position behind the load pick-up position FP and closer to the vehicle body 11 than the load pick-up position FP. The load W at the retraction position BP is located behind the vehicle body 11.

[0034] The tilt device 70 adjusts the position of the support surface 451 on the conveyor 45 by oscillating the conveyor 45. The conveyor 45 can take on a reference position, a tilt-up position, and a tilt-down position by being driven by the tilt device 70. The reference position is the position where the support surface 451 is horizontal. As shown by the solid line in Figure 6, the tilt-up position is the position where the front end of the conveyor 45 is higher than the reference position. Although not shown, the tilt-down position is the position where the front end of the conveyor 45 is lower than the reference position. These changes in the position of the conveyor 45 are performed by the tilt device 70.

[0035] The support shaft 71a swings in the forward / backward direction X by the drive of the tilt motor 71. The tilt encoder 72 detects the rotation angle of the tilt motor 71 and outputs a detection signal related to the detected rotation angle to the tilt control unit 53, which will be described later. The tilt motor 71 is connected to the lower end of the support shaft 71a. The conveyor motor 42 is connected to the upper end of the support shaft 71a. As described above, the conveyor motor 42 and the two conveyors 45 are integrated by the roller support member 45d and the connecting member 46. Therefore, when the support shaft 71a swings in the forward / backward direction X by the drive of the tilt motor 71, the conveyor motor 42 connected to the support shaft 71a also swings in the forward / backward direction X, and the two conveyors 45 also swing in the forward / backward direction X. Then, the tilt device 70 simultaneously swings the two conveyors 45 so that the support shaft 71a extends in the vertical direction Z, causing the support surface 451 of each conveyor 45 to become a horizontal plane, and each conveyor 45 to be positioned at its reference position.

[0036] <Vehicle Body Posture> The vehicle body 11 of the cargo handling mobile vehicle 10 can assume a standard posture T1, a forward-tilted posture T2, and a backward-tilted posture T3.

[0037] As shown in Figure 1, in a side view of the cargo handling mobile body 10, the standard posture T1 is a posture in which the installation surface 351 is parallel to the travel surface F. As shown by the dashed line in Figure 4, 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 addition, in the forward-tilted posture T2, the upper end of the vehicle body 11 is positioned in front of the lower end of the vehicle body 11. In a side view of the cargo handling mobile body 10, the installation surface 351 in the forward-tilted posture T2 is downward at the front. Note that "downward at the front" means that the front 11a side of the installation surface 351 is lower than the rear 11b side. The cargo handling mobile body 10 can assume the forward-tilted posture T2 while the conveyor 45 is in one of the following positions: the standard position, the tilt-up position, or the tilt-down position, under the control of the tilt control unit 53.

[0038] As shown by the solid line in Figure 4, in a side view of the cargo handling mobile body 10, the rearward tilt posture T3 is a posture in which the vehicle body 11 is tilted further back than the reference posture T1. Also, in the rearward tilt posture T3, the upper end of the vehicle body 11 is positioned behind the lower end of the vehicle body 11. In a side view of the cargo handling mobile body 10, the mounting surface 351 in the rearward tilt posture T3 is downward at the rear. Note that "downward at the rear" means that the rear surface 11b side of the mounting surface 351 is lower than the front surface 11a side. The cargo handling mobile body 10 can assume the rearward tilt posture T3 while the conveyor 45 remains in one of the following positions: the reference position, the tilt-up position, or the tilt-down position, under the control of the tilt control unit 53.

[0039] The control device 50 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, thereby enabling the vehicle body 11 to be in a standard posture T1, a forward-tilted posture T2, or a rearward-tilted posture T3, whether the load W is supported on the conveyor 45 or not. Furthermore, the control device 50 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, thereby enabling the posture control unit 51 to change the position of the center of gravity G in the longitudinal direction X, whether the load W is supported on the conveyor 45 or not.

[0040] The center of gravity G is the combined center of gravity of the cargo handling mobile body 10 and the cargo W when the cargo W is supported on the conveyor 45, and the center of gravity of the cargo handling mobile body 10 when the cargo W is not supported on the conveyor 45. The weight of the conveyor 45 will be ignored for the sake of simplicity. The position of the center of gravity G in the longitudinal direction X is determined based on the weight of the cargo handling mobile body 10, the weight of the cargo W, the posture of the vehicle body 11, and the position of the cargo W in the longitudinal direction X.

[0041] In a side view of the cargo handling mobile vehicle 10, a virtual line M is defined as the reference line, passing through the axis L in the vertical direction Z and extending in the vertical direction of the vehicle body 11. The smaller of the angles 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. The center line N is a straight line perpendicular to the axis L and extending in the vertical direction of the vehicle body 11.

[0042] As shown in Fig. 1, in the reference posture T1 in a state where the load W is not supported by the conveyor 45, the center line N coincides with the reference line M, and the center of gravity G is located on the reference line M. In this case, the tilt angle θ is zero.

[0043] As shown by the two-dot chain line in Fig. 4, in the forward tilt posture T2, since the center line N is located on the front side of the reference line M, the tilt angle θ is formed on the front side of the reference line M. As shown by the solid line in Fig. 4, in the rear tilt posture T3, since the center line N is located on the rear side of the reference line M, the tilt angle θ is formed on the rear side of the reference line M.

[0044] In the load handling mobile body 10, after the load W is supported by the conveyor 45 at the load handling position FP and the conveyor belt 45c is rotated, the position where the load of the load W is generated changes with the displacement of the load W. For example, when the load W at the load handling position FP is displaced to the retraction position BP, the position where the load of the load W is generated also moves from the load handling position FP to the retraction position BP. Then, the position of the center of gravity G fluctuates from the front to the rear.

[0045] The control device 50 adjusts the tilt angle θ to the target angle at which the load handling mobile body 10 stands upright without falling, according to the position of the load W in the front-rear direction X in a state where the load W is supported by the conveyor 45. Further, the control device 50 adjusts the rotation amounts of the right drive wheel 31 and the left drive wheel 32 to the target rotation amounts in order to make the load handling mobile body 10 stand upright without falling. Thereby, the posture of the vehicle body 11 is controlled, and the load handling mobile body 10 stands upright in a stopped state. The control device 5 having performed the above-described control will be described below.

[0046] <Control Device> The control device 50 controls the entire load handling mobile body 10. Further, the control device 50 controls the right wheel drive unit 21 and the left wheel drive unit 25, and the load handling device 40.

[0047] The control device 50 includes a processor and a storage unit. Examples of the processor include a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a DSP (Digital Signal Processor). The storage unit includes a RAM (Random Access Memory) and a ROM (Read Only Memory). The storage unit stores program codes or instructions configured to cause the processor to execute processing. The storage unit, that is, the computer-readable medium, includes any available medium accessible by a general-purpose or dedicated computer. The control device 50 may be constituted by a hardware circuit 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 an FPGA, or a combination thereof.

[0048] As shown in FIG. 5, the control device 50 includes an attitude control unit 51, a position control unit 52, a tilt control unit 53, a conveyor control unit 54, and a determination unit 58. The tilt control unit 53 and the conveyor control unit 54 constitute a cargo handling device control unit 59 that controls the drive of the cargo handling device 40. Therefore, the control device 50 includes the cargo handling device control unit 59 that controls the drive of the cargo handling device 40. Further, a measurement unit 51a, an input unit 55, a communication unit 56, and a reaction force estimation unit 57 are connected to the control device 50.

[0049] <Input Unit> The input unit 55 outputs various commands for driving the cargo handling mobile body 10. The input unit 55 inputs various commands to the control device 50.

[0050] <Communication Unit> The communication unit 56 inputs a position command to the position control unit 52. The position command is a command for moving the cargo handling mobile unit 10, such as the movement path and movement speed of the cargo handling mobile unit 10. The position command related to the movement path, for example, commands the position from the initial standby position of the cargo handling mobile unit 10 to the position where the cargo W is unloaded via the cargo handling platform 100. In accordance with this position command, the cargo handling mobile unit 10 moves forward from the initial standby position to near the cargo handling platform 100, then stops at a proximity position within a predetermined distance from the cargo handling platform 100 and performs cargo handling.

[0051] Detection of approaching positions along the movement path is performed by a position information detection unit (not shown) provided in the cargo handling mobile body 10. The position information detection unit (not shown) transmits the detected position signal to a higher-level control device (not shown). For example, the position information detection unit detects the position information of the cargo handling mobile body 10 by detecting the addresses of magnetic markers provided on the movement path of the cargo handling mobile body 10. Some of the multiple magnetic markers are provided at positions approaching the cargo handling platform 100. The positions where these magnetic markers are provided are the positions where the cargo handling mobile body 10 begins to swing its body 11 for cargo handling. The position information detection unit may also be an information processing device equipped with a camera or laser sensor and storing map data of the movement path, and may detect the position information of the cargo handling mobile body 10 by SLAM (Simultaneous Localization and Mapping) or the like.

[0052] When the higher-level control unit receives the position signal transmitted by the position information detection unit, it transmits a stop command to the cargo handling mobile unit 10 to stop it at the approach position. The higher-level control unit also transmits a load signal related to the load W to be handled at the approach position to the cargo handling mobile unit 10. The communication unit 56 receives the stop command and load signal and outputs the stop command and load signal to the control unit 50. The control unit 50 then controls the drive of the right wheel drive motor 22 and the left wheel drive motor 27. As a result, the cargo handling mobile unit 10 decelerates and stops. After that, the cargo handling mobile unit 10 performs cargo handling based on the control of the control unit 50. Before the cargo handling is completed, the control unit 50 controls the drive of the right wheel drive motor 22 and the left wheel drive motor 27 according to the position command to move the cargo handling mobile unit 10 slightly backward. At this time, the right drive wheel 31 and the left drive wheel 32 rotate at a target rotation amount calculated by the control unit 50. After the loading and unloading is complete, the control device 50 controls the driving of the right-wheel drive motor 22 and the left-wheel drive motor 27 according to the position command, and reverses the loading and unloading mobile body 10 to the position where the load W will be unloaded. Then, according to the position command, the loading and unloading mobile body 10 unloads the load W at the unloading position. Note that the position command related to the movement path may be changed as desired.

[0053] <Position Control Unit> The position control unit 52 calculates the acceleration and target speed of the cargo handling mobile body 10 according to the position command output from the communication unit 56. The position control unit 52 drives the right wheel drive motor 22 in the right wheel drive unit 21 and the left wheel drive motor 27 in the left wheel drive unit 25 according to the calculated acceleration and target speed. As a result, the cargo handling mobile body 10 travels along the travel path at the travel speed.

[0054] 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 detects the rotational angular velocity of the right drive wheel 31 and acquires the rotational angular velocity of 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 movement speed according to the position command.

[0055] <Tilt Control Unit> The input unit 55 inputs a tilt command value to the tilt control unit 53. The tilt command value is a command value for controlling the conveyor 45 to the reference position, tilt-up position, and tilt-down position. The tilt control unit 53 is connected to the tilt motor 71 and the tilt encoder 72. The tilt encoder 72 detects the rotation angle of the tilt motor 71 and outputs a detection signal related to the detected rotation angle to the tilt control unit 53. The tilt control unit 53 drives the tilt motor 71 according to the tilt command value and based on the detection signal related to the rotation angle detected by the tilt encoder 72, and controls the conveyor 45 to the reference position, tilt-up position, or tilt-down position.

[0056] The tilt control unit 53 controls the drive of the tilt motor 71 according to the tilt command value from the time the load W is lifted from the loading platform 100 and supported at the loading position FP until the load W is displaced to the retraction position BP. As a result, the conveyor 45 is positioned in the tilt-up position. Specifically, from the time the load W is supported at the loading position FP until it is displaced to the retraction position BP, the tilt control unit 53 controls the drive of the tilt motor 71 so that the central axis of the support shaft 71a extends in a state that is slightly tilted backward from the vertical direction Z. As a result, the conveyor 45 is maintained in the tilt-up position.

[0057] Before supporting a load W on the conveyor 45, the tilt control unit 53 controls the drive of the tilt motor 71 according to the tilt command value to position the conveyor 45 at the reference position. When unloading, the tilt control unit 53 controls the drive of the tilt motor 71 according to the tilt command value to position the conveyor 45 at the tilt-down position.

[0058] <Conveyor Control Unit> The conveyor control unit 54 controls the drive of the conveyor 45. The input unit 55 inputs a transport command value to the conveyor control unit 54. The transport command value is a command value for displacing the load W from the load picking position FP to the pull-in position BP. The load picking position FP and the pull-in position BP are predetermined positions as described above. The conveyor control unit 54 is connected to the conveyor motor 42 and the conveyor encoder 43. The conveyor encoder 43 detects the rotation angle of the conveyor motor 42 and outputs a detection signal related to the detected rotation angle to the conveyor control unit 54. The conveyor control unit 54 drives the conveyor motor 42 according to the transport command value and based on the detection signal related to the rotation angle detected by the conveyor encoder 43. The conveyor control unit 54 controls the drive of the conveyor motor 42 based on the detection signal of the conveyor encoder 43 so that the circumference of the conveyor belt 45c is the amount required to displace the load W from the load picking position FP to the pull-in position BP.

[0059] During cargo handling by the cargo handling device 40, the conveyor control unit 54 controls the drive of the conveyor motor 42 from the time the load W is supported at the loading position FP until it is displaced to the retraction position BP. As described above, the tilt control unit 53 maintains the conveyor 45 in the tilt-up position while the load W is being displaced from the loading position FP to the retraction position BP. Therefore, the cargo handling device 40 can displace the load W from the loading position FP to the retraction position BP while maintaining the tilt-up position through the control of the tilt control unit 53 and the conveyor control unit 54, that is, through the control of the cargo handling device control unit 59.

[0060] <Attitude Control Unit> The attitude control unit 51 controls the drive of the right wheel drive motor 22 in the right wheel drive unit 21 and the left wheel drive motor 27 in the left wheel drive unit 25, thereby controlling the attitude of the vehicle body 11 by oscillating the vehicle body 11 with the axis L as the pivot point.

[0061] The attitude control unit 51 is connected to a measurement unit 51a, a right-wheel drive motor 22, a left-wheel drive motor 27, a conveyor encoder 43, and a communication unit 56. The measurement unit 51a is an IMU (Inertial Measurement Unit). 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.

[0062] The measurement unit 51a measures the inclination angle θ of the vehicle body 11 at any time, such as when the load W is not supported by the conveyor 45, when the load W is supported at the load picking position FP, when the load W is being transported by the conveyor 45, when the load W is supported at the pull-in position BP, etc. The measurement unit 51a detects changes in the inclination angle θ of the vehicle body 11 in the front-rear direction X.

[0063] Whether the load W is supported on the conveyor 45 or not, the attitude control unit 51 obtains the inclination angle θ from the measurement unit 51a. The inclination angle θ changes according to the center of gravity G. The attitude control unit 51 also obtains information related to the weight of the load W from the load signal output by the communication unit 56, and obtains information related to the position of the load W on the conveyor 45 from the detection signal output by the conveyor encoder 43. Based on the load signal related to the load W, the detection signal related to the obtained inclination angle θ, and the detection signal related to the rotation angle from the conveyor encoder 43, the attitude control unit 51 calculates the target angle at which the vehicle body 11 can stand upright as needed.

[0064] 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 to achieve the calculated target angle. 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 based on the position of the center of gravity G corresponding to the position of the load W, and the cargo handling mobile body 10 is inverted in the controlled attitude. Specifically, the attitude control unit 51 swings the vehicle body 11 in the longitudinal direction X using 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, thereby changing the center of gravity G in the longitudinal direction X.

[0065] Furthermore, as described above, after displacing the load W to the retraction position BP, the cargo handling mobile body 10 moves slightly backward according to the position command. At this time, the attitude control unit 51 controls the driving 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 rotate the right drive wheel 31 and the left drive wheel 32 by a target amount of rotation.

[0066] Specifically, when the load W is displaced to the retraction position BP and the cargo handling mobile body 10 is maintained in an inverted state with a rearward tilt posture T3, the right drive wheel 31 and the left drive wheel 32 tend to rotate in the forward direction due to the influence of the center of gravity G. In order to stop the rotation of the right drive wheel 31 and the left drive wheel 32 and keep the body inverted, the attitude control unit 51 controls the drive of 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 by a target amount. In other words, the attitude control unit 51 adjusts the amount of rotation of the right drive wheel 31 and the left drive wheel 32 to a target amount. The attitude control unit 51 calculates the target amount of rotation based on the load signal related to the load W, the detection signal related to the acquired tilt angle θ, and the detection signal related to the rotation angle from the conveyor encoder 43.

[0067] Before loading and unloading, specifically before supporting the load W at the loading position FP, the attitude control unit 51 inverts the vehicle body 11 to a reference posture T1. At this time, the attitude control unit 51 calculates a target angle for inverting the loading and unloading vehicle body 10 to the reference posture T1, and uses the right wheel drive unit 21 and the left wheel drive unit 25 to swing the vehicle body 11 in the longitudinal direction X, thereby changing the position of the center of gravity G in the longitudinal direction X.

[0068] As shown in Figure 6, the cargo handling mobile vehicle 10 can be supported on the cargo handling platform 100 by bringing the upper end of the front surface 11a of the vehicle body 11 into contact with the cargo handling platform 100. When the vehicle body 11 comes into contact with the cargo handling platform 100, the vehicle body 11 receives a reaction force from the cargo handling platform 100.

[0069] <Reaction Force Estimation Unit> As shown in Figure 5, the reaction force estimation unit 57 is connected to the measurement unit 51a and the determination unit 58. The reaction force estimation unit 57 estimates the force supported by the loading platform 100 when the vehicle body 11 is tilted forward and in contact with the loading platform 100 as the [reaction force]. The reaction force is zero when the vehicle body 11 is not in contact with the loading platform 100. When the vehicle body 11 is tilted forward and comes into contact with the loading platform 100, a reaction force is generated in the vehicle body 11. The greater the amount the vehicle body 11 tilts forward toward the loading platform 100, in other words, the larger the tilt angle θ in the forward tilting direction, the larger the reaction force.

[0070] When the vehicle body 11 comes into contact with the loading platform 100 while tilted, the reaction force estimation unit 57 obtains the tilt angle θ from the measurement unit 51a and estimates the reaction force corresponding to the obtained tilt angle θ. The reaction force may be estimated by calculation from the tilt angle θ obtained from the measurement unit 51a, or it may be estimated using a data map or table pre-stored in the attitude control unit 51. In short, the method of estimation is arbitrary as long as the reaction force estimation unit 57 can estimate the reaction force from the obtained tilt angle θ. The reaction force estimation unit 57 outputs information related to the estimated reaction force to the determination unit 58, which will be described later.

[0071] <Determination Unit> The determination unit 58 obtains information related to the reaction force from the reaction force estimation unit 57. The determination unit 58 determines whether the reaction force estimated by the reaction force estimation unit 57 is sufficient to support the gravitational moment of the cargo handling mobile body 10. The gravitational moment is generated when the cargo handling mobile body 10 is tilted. The gravitational moment increases as the tilt angle θ increases. If the reaction force from the cargo handling platform 100 does not match the gravitational moment of the cargo handling mobile body 10, the cargo handling mobile body 10 is not supported by the cargo handling platform 100. In this case, the attitude control unit 51 controls the tilt angle θ to increase in order to make the reaction force match the gravitational moment.

[0072] <Operation of the cargo handling mobile unit and control of the control device> Next, the operation of the cargo handling mobile unit 10 will be explained along with the control method for the cargo handling mobile unit 10. The operation of the cargo handling mobile unit 10 is started by the operator after various commands such as the movement path and movement speed are input to the control device 50 by the communication unit 56. As shown in Figure 1, the body 11 of the cargo handling mobile unit 10 is controlled to a reference posture T1 by the posture control unit 51 when the load W is not supported on the conveyor 45.

[0073] The cargo handling mobile unit 10 moves along its path and approaches the cargo handling platform 100. While the cargo handling mobile unit 10 is moving, a position information detection unit (not shown) detects the position of the cargo handling mobile unit 10 along its path. The higher-level control unit then understands that the cargo handling mobile unit 10 is approaching the cargo handling platform 100 based on the position signal detected by the position information detection unit. When the cargo handling mobile unit 10 has moved to an approaching position near the cargo handling platform 100, the higher-level control unit transmits a stop command to the cargo handling mobile unit 10 to stop it at the approaching position. The communication unit 56 also receives a load signal. Upon receiving the stop command in the communication unit 56, the cargo handling mobile unit 10 decelerates by controlling the right-wheel drive motor 22 and the left-wheel drive motor 27 and stops at the approaching position. As the cargo handling mobile body 10 decelerates towards the approaching position, the front end of the conveyor 45 is inserted between a pair of pallet mounting platforms 102 placed on the mounting surface 100a of the cargo handling platform 100.

[0074] When the cargo handling mobile body 10 reaches the approach position, the attitude control unit 51 calculates a target angle for the vehicle body 11 to contact the cargo handling platform 100 with a forward tilt T2. Furthermore, the attitude control unit 51 synchronously drives the right wheel drive motor 22 in the right wheel drive unit 21 and the left wheel drive motor 27 in the left wheel drive unit 25 to rotate the right drive wheel 31 and the left drive wheel 32 in a synchronous reverse direction, thereby tilting the vehicle body 11 forward and shifting the center of gravity G forward of the reference line M, in order to set the tilt angle θ to the target angle. At this time, the attitude control unit 51 obtains the tilt angle θ from the measurement unit 51a and, based on the detection signal related to the obtained tilt angle θ, synchronously drives the right wheel drive motor 22 in the right wheel drive unit 21 and the left wheel drive motor 27 in the left wheel drive unit 25 so that the tilt angle θ gradually increases. The attitude control unit 51 tilts the vehicle body 11 forward so that the tilt angle θ becomes the target angle, while obtaining the tilt angle θ from the measurement unit 51a, in order to achieve a forward-tilted posture T2 at the target angle.

[0075] Furthermore, the tilt control unit 53 controls the drive of the tilt motor 71 in accordance with the increasing tilt angle θ, controlling the central axis of the support shaft 71a to extend in the vertical direction Z, thereby maintaining the conveyor 45 in its reference position, i.e., the support surface 451 of the conveyor 45 in a horizontal plane. Also, as the vehicle body 11 tilts forward, the front end of the conveyor 45 is further inserted between the pallet mounting tables 102 while maintaining the support surface 451 in a horizontal plane.

[0076] As the vehicle body 11 tilts forward, a gravitational moment is generated on the cargo handling mobile body 10 directed forward and diagonally downward from the vehicle body 11. As shown in Figure 6, when the upper end of the front surface 11a of the vehicle body 11 contacts the cargo handling platform 100 and the tilt angle θ reaches the target angle, the determination unit 58 determines whether the reaction force estimated by the reaction force estimation unit 57 matches the reaction force sufficient to support the gravitational moment of the cargo handling mobile body 10. If the determination unit 58 determines that the estimated reaction force matches the reaction force sufficient to support the gravitational moment of the cargo handling mobile body 10, it outputs a match signal to the attitude control unit 51 indicating that the reaction forces match. When the attitude control unit 51 receives the match signal, it stops driving the right wheel drive motor 22 and the left wheel drive motor 27.

[0077] On the other hand, if the determination unit 58 determines that the estimated reaction force does not match the reaction force sufficient to support the gravitational moment of the cargo handling mobile body 10, it outputs a mismatch signal to the attitude control unit 51 indicating that there is a mismatch. When the attitude control unit 51 receives a mismatch signal, it continues to drive the right wheel drive motor 22 and the left wheel drive motor 27, and continues to oscillate the vehicle body 11. If the reaction force from the cargo handling platform 100 does not match the gravitational moment of the cargo handling mobile body 10, the cargo handling mobile body 10 is not supported by the cargo handling platform 100. Therefore, in order to match the reaction force to the gravitational moment, the attitude control unit 51 controls the tilt angle θ to increase. Accordingly, the attitude control unit 51 oscillates the vehicle body 11 based on the reaction force information obtained from the reaction force estimation unit 57.

[0078] As a result, the right drive wheel 31 and the left drive wheel 32 rotate further in the reverse direction, increasing the inclination angle θ and the gravitational moment of the cargo handling mobile body 10. As the gravitational moment increases, the reaction force from the cargo handling platform 100 also increases. When the reaction force matches the gravitational moment of the cargo handling mobile body 10, the cargo handling mobile body 10 is supported by the cargo handling platform 100. In other words, when a reaction force sufficient to support the gravitational moment of the cargo handling mobile body 10 is generated at the contact point between the cargo handling platform 100 and the vehicle body 11, the cargo handling mobile body 10 is supported by the cargo handling platform 100.

[0079] Furthermore, when the cargo handling mobile body 10 is supported on the cargo handling platform 100, the right drive wheel 31 and the left drive wheel 32 are at a position further rearward from the cargo handling platform 100 than when they reached the approach position. Therefore, the attitude control unit 51 can create a state in which the cargo handling mobile body 10 is supported on the cargo handling platform 100. Accordingly, before the cargo handling device control unit 59 drives the cargo handling device 40 to perform cargo handling, the attitude control unit 51 can support the vehicle body 11 on the cargo handling platform 100, which acts as a vehicle body support, and also swing the vehicle body 11 to a forward tilted position T2 to support the vehicle body 11 on the cargo handling platform 100. The control method for the cargo handling mobile body 10 includes the attitude control unit 51 swinging the vehicle body 11 to support the vehicle body 11 in an inclined position on the cargo handling platform 100. In detail, in the control method for the cargo handling mobile body 10, the attitude control unit 51 swings the vehicle body 11 to a forward-tilting position T2 to support the vehicle body 11 on the cargo handling platform 100. Furthermore, in the control method for the cargo handling mobile body 10, before the conveyor control unit 54 of the cargo handling device control unit 59 drives the conveyor 45 to perform cargo handling, the attitude control unit 51 supports the vehicle body 11 on the cargo handling platform 100.

[0080] Then, while tilting the vehicle body 11 forward, and supporting the vehicle body 11 on the loading platform 100, the tilt control unit 53 drives the tilt motor 71 to control the conveyor 45 to the tilt-up position. As a result, the loading mobile unit 10 supports the load W on the conveyor 45 in front of the vehicle body 11, that is, at the loading position FP. Therefore, the loading mobile unit 10 can assume a forward-tilted posture T2 in which the upper end of the vehicle body 11 is positioned in front of the lower end of the vehicle body 11 while supporting the load W on the conveyor 45 in front of the vehicle body 11.

[0081] Next, the conveyor control unit 54 controls the drive of the conveyor motor 42 to make the conveyor belt 45c circulate and displace the load W at the load pick-up position FP toward the retraction position BP. Therefore, in the control method for the cargo handling mobile body 10, the conveyor control unit 54 drives the cargo handling device 40 to displace the load W from the load pick-up position FP to a position different from the load pick-up position FP, specifically to a position behind the load pick-up position FP and toward the retraction position BP on the vehicle body 11 side.

[0082] As the load W is displaced from the loading position FP towards the retraction position BP, the position where the load of the load W is generated changes from the front to the rear of the vehicle body 11. In other words, as the load W is displaced from the loading position FP towards the retraction position BP, the center of gravity G shifts from the loading position FP towards the retraction position BP as the load W is displaced. As a result, the center of gravity G approaches the reference line M. In other words, in the cargo handling mobile vehicle 10, a change in the center of gravity G occurs at the start of cargo handling. At this time, the cargo handling mobile vehicle 10 maintains a stable forward-tilting posture T2 due to two-point contact: the contact of the right drive wheel 31 and the left drive wheel 32 with the running surface F, and the contact of the vehicle body 11 with the cargo handling platform 100. For this reason, the cargo handling mobile vehicle 10 can stably displace the load W, especially initiating the displacement of the load W. Therefore, the control method for the cargo handling mobile body 10 includes the conveyor control unit 54 of the cargo handling device control unit 59 driving the cargo handling device 40 to perform cargo handling while the vehicle body 11 is supported on the cargo handling platform 100.

[0083] As the load W is further displaced from the loading position FP to the retraction position BP, the center of gravity G approaches the reference line M. In accordance with this change in the center of gravity G, the right drive wheel 31 and the left drive wheel 32 rotate in the forward direction while the vehicle body 11 remains supported on the loading platform 100, causing the vehicle body 11 to swing in a direction that naturally leads to an upright position. In other words, as shown in Figure 7, the right drive wheel 31 and the left drive wheel 32 approach the loading platform 100. As a result, the vehicle body 11 swings in a direction that slightly straightens its forward-leaning posture T2.

[0084] During the displacement of the load W as described above, that is, during cargo handling, the attitude control unit 51 acquires the inclination angle θ from the measurement unit 51a and calculates the target angle of the vehicle body 11, but does not output commands to the right wheel drive unit 21 and the left wheel drive unit 25. Therefore, when the load W is displaced by the conveyor 45, the cargo handling mobile body 10 does not actively swing the vehicle body 11 through control by the attitude control unit 51.

[0085] Furthermore, as the conveyor belt 45c rotates and the load W is displaced beyond the reference line M and behind the vehicle body 11, approaching the retraction position BP, the right drive wheel 31 and the left drive wheel 32 begin to rotate in the reverse direction in accordance with the change in the center of gravity G. At this time, the attitude control unit 51 also obtains the inclination angle θ from the measurement unit 51a and calculates the target angle for inverting the vehicle body 11. The attitude control unit 51 drives the right wheel drive motor 22 and the left wheel drive motor 27 in sync so that the inclination angle θ becomes the calculated target angle, thereby rotating the right drive wheel 31 and the left drive wheel 32.

[0086] Then, as shown in Figure 8, as the load W approaches the retraction position BP, the rotation of the right drive wheel 31 and left drive wheel 32 in the direction that the vehicle body 11 tilts backward causes the vehicle body 11 to begin to move away from the loading platform 100. At this time, the attitude control unit 51 controls the loading / unloading mobile body 10 to drive the right wheel drive motor 22 and the left wheel drive motor 27 in synchronous motion so that the tilt angle θ of the vehicle body 11 becomes the calculated target angle. As the load W is displaced to the retraction position BP and maintained in an inverted state with a rearward tilted posture T3, the right drive wheel 31 and the left drive wheel 32 attempt to rotate under the influence of the center of gravity G. At this time, according to the position command, the attitude control unit 51 controls the driving of 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 by the target amount of rotation.

[0087] As a result, the cargo handling mobile body 10 moves slightly backward while remaining upside down, and its center of gravity G shifts slightly, causing the vehicle body 11 to move away from the loading platform 100 while maintaining its upside-down position. The cargo handling mobile body 10 then stands upside down at a position slightly away from the loading platform 100. Therefore, the control method for the cargo handling mobile body 10 includes the conveyor control unit 54 in the cargo handling device control unit 59 driving the conveyor motor 42 of the cargo handling device 40 to displace the load W from the loading position FP to the retraction position BP, and the attitude control unit 51 driving the right wheel drive unit 21 and the left wheel drive unit 25 in conjunction with this to maintain the upside-down position of the vehicle body 11.

[0088] Subsequently, 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 communication unit 56. 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 backward while maintaining the rearward tilted posture T3.

[0089] [Effects of the First Embodiment] According to the first embodiment described above, the following effects can be obtained. (1-1) In the control method for the cargo handling mobile body 10, when the vehicle body 11 is supported on the cargo handling platform 100, a reaction force is generated on the vehicle body 11 from the cargo handling platform 100. In response to this reaction force, the vehicle body 11 maintains a stable posture despite being in an inclined position. In other words, the cargo handling mobile body 10 is in a state of two-point contact, with the right drive wheel 31 and the left drive wheel 32 in contact with the running surface F and the vehicle body 11 in contact with the cargo handling platform 100. As a result, the posture of the vehicle body 11 is more stable compared to a state where only the right drive wheel 31 and the left drive wheel 32 are in contact with the running surface F. Furthermore, since the control method performs cargo handling with the vehicle body 11 in a state where its posture is stabilized by two-point contact, it is no longer necessary to stabilize the posture of the vehicle body 11 by swinging it with the posture control unit 51, even in situations where fluctuations in the center of gravity G occur during cargo handling. As a result, the control method for the cargo handling mobile unit 10 enables stable cargo handling.

[0090] (1-2) In the control method for the cargo handling mobile body 10, the attitude control unit 51 swings the vehicle body 11 to a forward tilted position T2 to support the vehicle body 11 on the cargo handling platform 100. For example, compared to the case where the load W is moved from the loading position FP to the retraction position BP in a rearward tilted position T3 with the upper end of the vehicle body 11 positioned behind the lower end of the vehicle body 11, the cargo handling mobile body 10 can perform cargo handling with the vehicle body 11 in a stable position.

[0091] (1-3) In the control method for the cargo handling mobile body 10, as the load W is displaced behind the reference line M of the vehicle body 11 and the cargo handling mobile body 10 moves away from the cargo handling platform 100, the attitude control unit 51 drives the right wheel drive motor 22 and the left wheel drive motor 27 to maintain the inverted position of the vehicle body 11. As the load W is displaced from the load picking position FP to the pull-in position BP, the right drive wheel 31 and the left drive wheel 32 rotate in a direction that tilts the vehicle body 11 backward. In conjunction with this, the attitude control unit 51 drives the right wheel drive motor 22 and the left wheel drive motor 27 to maintain the inverted position of the vehicle body 11, so that the vehicle body 11 moves away from the cargo handling platform 100 while maintaining its inverted position. As a result, after cargo handling, the cargo handling mobile body 10 can be quickly reversed toward a location away from the cargo handling platform 100.

[0092] (1-4) The attitude control unit 51 calculates the target angle while the vehicle body 11 is supported on the loading platform 100 and the load W is being displaced. Therefore, immediately after the vehicle body 11 separates from the loading platform 100, the vehicle body 11 can be swung so that the inclination angle θ becomes the target angle. As a result, the loading and unloading mobile body 10 can quickly move backward while remaining upside down even immediately after the vehicle body 11 separates from the loading platform 100.

[0093] (1-5) The control method for the cargo handling mobile body 10 allows cargo handling to be performed by the conveyor 45 while the vehicle body 11 is supported on the cargo handling platform 100. Therefore, compared to the case where the vehicle body 11 is swung each time a change in the center of gravity G occurs due to cargo handling, the displacement of the load W from the loading position FP to the retraction position BP can be performed quickly and accurately, thus improving cargo handling efficiency. Furthermore, since it is not necessary to increase the weight of the balance weight required to invert the vehicle body 11, such as immediately after the start of the displacement of the load W from the loading position FP to the retraction position BP, the weight of the vehicle body 11 used as a balance weight can be reduced.

[0094] (1-6) Before the conveyor 45 supports the load W, the attitude control unit 51 supports the vehicle body 11 on the loading platform 100. In other words, the loading vehicle 10 can start loading with a stable attitude due to two-point contact: the right drive wheel 31 and the left drive wheel 32 touching the ground, and the vehicle body 11 contacting the loading platform 100.

[0095] (1-7) The control device 50 includes a reaction force estimation unit 57 that estimates the reaction force that the vehicle body 11, supported on the loading platform 100, receives from the loading platform 100. The attitude control unit 51 then oscillates the vehicle body 11 based on the reaction force information obtained from the reaction force estimation unit 57. Therefore, by obtaining the reaction force information from the reaction force estimation unit 57, the attitude control unit 51 can accurately support the vehicle body 11 on the loading platform 100 in a stable state.

[0096] (1-8) The control method for the cargo handling mobile vehicle 10 allows cargo handling to be performed with the vehicle body 11 supported on the cargo handling platform 100, so it is not necessary to continuously perform control to swing the vehicle body 11 by the attitude control unit 51 throughout the cargo handling. Therefore, the control method for the cargo handling mobile vehicle 10 can reduce the processing load on the attitude control unit 51.

[0097] (1-9) The cargo handling mobile body 10 determines whether the vehicle body 11 is supported on the cargo handling platform 100 based on the reaction force estimated by the reaction force estimation unit 57. For example, compared to a case where a sensor that detects the reaction force on the vehicle body 11 is used to determine whether the vehicle body 11 is supported on the cargo handling platform 100, the number of parts of the cargo handling mobile body 10 can be reduced.

[0098] [Second Embodiment] Next, a second embodiment that embodies the control method for the cargo handling mobile body will be described with reference to Figures 9 to 11. 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.

[0099] As shown in Figure 9, the cargo handling mobile body 10, which performs cargo handling on the cargo W, is equipped with an arm 200 and a suction part 300 supported by the arm 200, instead of a conveyor 45. The cargo handling device 40 does not have a tilt device 70.

[0100] The arm 200 is installed on the mounting surface 351 of the vehicle body 11. The arm 200 comprises a first joint portion 201, a second joint portion 202, a third joint portion 203, a first arm forming portion 204, a second arm forming portion 205, and a third arm forming portion 206. The first joint portion 201 pivotably supports the first arm forming portion 204, and the second joint portion 202 pivotably supports the second arm forming portion 205. The third joint portion 203 pivotably supports the third arm forming portion 206. Each of the first arm forming portion 204, the second arm forming portion 205, and the third arm forming portion 206 is a rod-shaped rigid body. The lengths of the first arm forming portion 204, the second arm forming portion 205, and the third arm forming portion 206 can be appropriately changed according to the overall length of the arm 200, the weight of the suction portion 300, etc.

[0101] The first joint portion 201 is installed on the mounting surface 351. The first joint portion 201 is rotatable about a rotation axis (not shown) perpendicular to the mounting surface 351. The first joint portion 201 is equipped with a first joint motor 201a, and a first encoder 201b is connected to the first joint motor 201a. The rotation axis 201c of the first joint motor 201a is rotatably supported on the first joint portion 201 and extends horizontally. The rotation axis 201c of the first joint motor 201a is connected to the first end of the first arm forming portion 204. When the first joint motor 201a is driven and the rotation axis 201c rotates, the first arm forming portion 204 swings about the rotation axis 201c as the pivot point.

[0102] The second end of the first arm forming section 204 is fixed to the second joint section 202. Since the second joint section 202 is fixed to the first arm forming section 204, the second joint section 202 swings together with the first arm forming section 204. The second joint section 202 is equipped with a second joint motor 202a, and a second encoder 202b is connected to the second joint motor 202a. The rotation axis 202c of the second joint motor 202a is rotatably supported by the second joint section 202 and extends horizontally. The rotation axis 202c of the second joint motor 202a is connected to the first end of the second arm forming section 205. When the second joint motor 202a is driven and the rotation axis 202c rotates, the second arm forming section 205 swings about the rotation axis 202c as the pivot point.

[0103] The second end of the second arm forming section 205 is fixed to the third joint section 203. Since the third joint section 203 is fixed to the second arm forming section 205, the third joint section 203 swings together with the second arm forming section 205. The third joint section 203 is equipped with a third joint motor 203a, and a third encoder 203b is connected to the third joint motor 203a. The rotation axis 203c of the third joint motor 203a is rotatably supported by the third joint section 203 and extends horizontally. The rotation axis 203c of the third joint motor 203a is connected to the first end of the third arm forming section 206. When the third joint motor 203a is driven and the rotation axis 203c rotates, the third arm forming section 206 swings about the rotation axis 203c as the pivot point. A suction section 300 is fixed to the second end of the third arm forming section 206.

[0104] The arm 200 described above is a multi-axis arm. The arm 200 swings the first arm forming section 204 to the third arm forming section 206 by driving the first joint motor 201a to the third joint motor 203a. As a result, the arm 200 can change the position of the suction section 300 fixed to the third arm forming section 206 in either the front-rear direction X or the vertical direction Z. In addition, by rotating the first joint section 201 about a rotation axis (not shown), the arm 200 can change the position of the suction surface of the suction section 300 about the rotation axis.

[0105] The arm 200 is driven and controlled by an arm control unit 61 provided in the control device 50. The arm control unit 61 is connected to a first joint motor 201a, a second joint motor 202a, a third joint motor 203a, a first encoder 201b, a second encoder 202b, and a third encoder 203b.

[0106] The arm control unit 61 acquires detection signals detected by the first encoder 201b, the second encoder 202b, and the third encoder 203b. Based on the acquired detection signals, the arm control unit 61 detects the rotation angles of the first joint motor 201a, the second joint motor 202a, and the third joint motor 203a. Then, based on the detected rotation angles, the arm control unit 61 controls the driving of the first joint motor 201a to the third joint motor 203a to adjust the shape of the arm 200 and adjust the position of the suction part 300. As a result, the cargo handling mobile body 10 performs cargo handling on the cargo handling device 40. Therefore, the arm control unit 61 is a cargo handling device control unit that controls the driving of the cargo handling device 40.

[0107] <Control of the operation of the cargo handling mobile vehicle and the control device> When the cargo handling mobile vehicle 10 reaches the approach position, the attitude control unit 51 of the cargo handling mobile vehicle 10 calculates a target angle for bringing the vehicle body 11 into contact with the cargo handling platform 100. Furthermore, the attitude control unit 51 synchronously drives the right wheel drive motor 22 in the right wheel drive unit 21 and the left wheel drive motor 27 in the left wheel drive unit 25 to rotate the right drive wheel 31 and the left drive wheel 32 in a synchronous reverse direction in order to make the inclination angle θ the target angle, thereby tilting the vehicle body 11 forward and shifting the center of gravity G to a position in front of the reference line M.

[0108] As shown in Figure 10, when the upper end of the front surface 11a of the vehicle body 11 contacts the loading platform 100, and the reaction force acting on the vehicle body 11 matches the gravitational moment of the loading / unloading mobile body 10, the loading / unloading mobile body 10 is supported by the loading platform 100. Therefore, before driving the arm 200 to perform loading / unloading, the attitude control unit 51 can support the vehicle body 11 on the loading platform 100, which acts as a vehicle body support, and can also swing the vehicle body 11 to a forward-tilted position T2 to support the vehicle body 11 on the loading platform 100. Thus, the control method for the loading / unloading mobile body 10 includes the attitude control unit 51 swinging the vehicle body 11 to support the vehicle body 11 in an inclined position on the loading platform 100 before driving the loading / unloading device 40 to perform loading / unloading.

[0109] Furthermore, when supporting the vehicle body 11 on the loading platform 100, the arm control unit 61 controls the driving of the first joint motor 201a to the third joint motor 203a to adjust the shape of the arm 200 and the position of the suction part 300 in order to bring the suction surface of the suction part 300 facing the rear surface of the load W.

[0110] Next, the arm control unit 61 controls the driving of the first joint motors 201a to the third joint motors 203a to cause the load W to be picked up by the suction unit 300 at the load picking position FP, and to support the load W with the arm 200. Thus, with the load W supported by the arm 200, the cargo handling mobile body 10 can assume a forward-tilted posture T2 in which the upper end of the vehicle body 11 is positioned in front of the lower end of the vehicle body 11.

[0111] Next, with the vehicle body 11 supported on the loading platform 100, the arm control unit 61 controls the driving of the first joint motor 201a to the third joint motor 203a to cause the loading device 40 to perform loading and unloading. Then, as the load W is displaced from the loading position FP to the retraction position BP by the swinging of the first arm forming section 204 to the third arm forming section 206 of the arm 200, the center of gravity G shifts from the loading position FP to the retraction position BP as the load W is displaced. During this displacement of the load W, the attitude control unit 51 obtains the inclination angle θ from the measurement unit 51a and calculates the target angle for inverting the vehicle body 11. Then, the attitude control unit 51 synchronously drives the right wheel drive motor 22 and the left wheel drive motor 27 so that the inclination angle θ becomes the calculated target angle, and rotates the right drive wheel 31 and the left drive wheel 32. Therefore, the control method for the cargo handling mobile body 10 is such that the arm control unit 61 drives the cargo handling device 40 to displace the load W from the loading position FP to the retraction position BP, and the attitude control unit 51 drives the right wheel drive unit 21 and the left wheel drive unit 25 to maintain the inverted position of the vehicle body 11.

[0112] As the load W approaches the retraction position BP, the rotation of the right drive wheel 31 and left drive wheel 32 in the direction that the vehicle body 11 tilts backward causes the vehicle body 11 to begin to move away from the loading platform 100. At this time, the attitude control unit 51 controls the loading / unloading mobile body 10 to drive the right wheel drive motor 22 and the left wheel drive motor 27 in synchronous motion so that the tilt angle θ of the vehicle body 11 becomes the calculated target angle. As the load W is displaced to the retraction position BP and the vehicle is maintained in an inverted state with a rearward tilt T3, the right drive wheel 31 and the left drive wheel 32 attempt to rotate due to the influence of the center of gravity G. At this time, according to the position command, the attitude control unit 51 controls the driving of 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 by the target amount of rotation.

[0113] As a result, the cargo handling mobile body 10 moves slightly backward while remaining upside down, and its center of gravity G shifts slightly. As shown in Figure 11, the vehicle body 11 moves away from the cargo handling platform 100 while maintaining its upside-down position, and then becomes upside down at a position slightly away from the cargo handling platform 100.

[0114] Therefore, according to the second embodiment, the same effects as those described in (1-1) to (1-9) of the first embodiment can be obtained. [Modification Examples] Each embodiment can be implemented with the following modifications. Each embodiment and the following modifications can be combined with each other to the extent that they do not contradict the technical standards.

[0115] As shown in Figures 12 and 13, the cargo handling mobile body 10 of the second embodiment may, in the cargo handling device 40, instead of the suction part 300, be equipped with a support member 302 that supports the load W from below and has a hook part 301 that catches on the inner surface of the load W. Furthermore, the cargo handling mobile body 10 of the second embodiment may be equipped with a weight 210 on a part of the arm 200. The weight 210 is integrated with the first arm forming part 204 of the arm 200, but as will be explained later, if the center of gravity G can be changed in conjunction with the movement of the weight 210, the weight 210 may be integrated with a part other than the first arm forming part 204, for example, the second joint part 202.

[0116] As shown in Figure 12, when the load W is supported by the arm 200 at the load handling position FP, the weight 210 is located above the mounting surface 351 on the vehicle body 11. The arm control unit 61 controls the driving of the first joint motors 201a to the third joint motors 203a to operate the arm 200 so that the first arm forming section 204 and the second arm forming section 205 overlap, thereby positioning the second joint section 202 behind the vehicle body 11. As a result, the weight 210 moves behind the rear surface 11b of the vehicle body 11. Along with the movement of the weight 210, the center of gravity G also shifts backward from the position shown in Figure 12. In other words, as the position of the load W is displaced from the load handling position FP to a different position, specifically below the load handling position FP, the center of gravity G shifts backward. Therefore, fluctuations in the center of gravity G may be caused not by the displacement of the load W in the longitudinal direction X, but also by the handling of the load by the handling device 40.

[0117] ○In the second embodiment, the cargo handling mobile body 10 may be equipped with a gripping member for gripping the load W in place of the suction part 300 in the cargo handling device 40. ○As shown in Figure 14, the cargo handling mobile body 10 may be equipped with a restricting unit 90 that restricts the rotation of the right drive wheel 31 and the left drive wheel 32, and a rotation restricting unit that controls the drive of the restricting unit 90. The restricting unit 90 is a so-called brake. The restricting unit 90 restricts the rotation of the right drive wheel 31 and the rotation of the left drive wheel 32 in a synchronized manner. The restricting unit 90 can be any type, such as electromagnetic, hydraulic, or drum, as long as it can restrict the rotation of the right drive wheel 31 and the left drive wheel 32. The rotation restricting unit is also the attitude control unit 51 of the control device 50. The rotation restricting unit may be provided in the control device 50 separately from the attitude control unit 51.

[0118] In this configuration, the control method for the cargo handling mobile body 10 includes the attitude control unit 51 supporting the vehicle body 11 on the cargo handling platform 100, and then the attitude control unit 51, acting as a rotation restricting unit, driving the restricting unit 90 to restrict the rotation of the right drive wheel 31 and the left drive wheel 32. At this time, the attitude control unit 51 stops controlling the drive of the right wheel drive motor 22 and the left wheel drive motor 27, and at the same time controls the drive of the restricting unit 90 to synchronously restrict the rotation of the right drive wheel 31 and the left drive wheel 32.

[0119] In this case, the rotation of the right drive wheel 31 and the left drive wheel 32 is restricted, so when cargo handling is performed with the vehicle body 11 supported on the loading platform 100, the rotation of the right drive wheel 31 and the left drive wheel 32 can be restricted. As a result, when cargo handling is performed in a two-point contact state, even if fluctuations in the center of gravity G occur due to cargo handling, the movement of the vehicle body 11 caused by the rotation of the right drive wheel 31 and the left drive wheel 32 is suppressed, so the cargo handling mobile body 10 can perform cargo handling stably.

[0120] As shown in Figure 15, the vehicle body support 110 may be positioned behind the cargo handling mobile body 10. In this case, the attitude control unit 51 tilts the vehicle body 11 backward, bringing the first main surface 121 of the machine base 12 into contact with the vehicle body support 110, thereby supporting the cargo handling mobile body 10 on the vehicle body support 110. Cargo handling may then be performed with the vehicle body 11 supported on the vehicle body support 110. As for cargo handling, although not shown, the load W may be displaced to the retraction position BP and then unloaded at the unloading position.

[0121] With this configuration, the control method for the cargo handling mobile body 10 stabilizes the posture of the vehicle body 11 through two-point contact while performing cargo handling. Therefore, even in situations where fluctuations in the center of gravity G occur during cargo handling, it becomes unnecessary to stabilize the posture of the vehicle body 11 by oscillating it with the posture control unit 51. As a result, with this control method for the cargo handling mobile body 10, the cargo handling mobile body 10 can perform cargo handling stably.

[0122] ○In each embodiment, the control method for the cargo handling mobile body 10 involves supporting the vehicle body 11 on the cargo handling platform 100 and then displacing the load W from the loading position FP to the retraction position BP, but this is not limited to this. The control method for the cargo handling mobile body 10 may also involve driving the cargo handling device 40 to start the displacement of the load W at the same time that the attitude control unit 51 supports the vehicle body 11 on the cargo handling platform 100. Alternatively, the control method for the cargo handling mobile body 10 may involve driving the cargo handling device 40 to start the displacement of the load W immediately before the attitude control unit 51 supports the vehicle body 11 on the cargo handling platform 100. In short, as long as the movement of the vehicle body 11 in the longitudinal direction X is suppressed during cargo handling by the cargo handling device 40, and cargo handling can be performed stably, the timing of supporting the vehicle body 11 on the cargo handling platform 100 and the timing of starting cargo handling by the cargo handling device 40 can be set appropriately.

[0123] ○The target angle at which the vehicle body 11 is tilted to support the vehicle body 11 on the loading platform 100 may be pre-inputted as a command value to the attitude control unit 51 by the input unit 55. Then, when supporting the vehicle body 11 on the loading platform 100, the attitude control unit 51 acquires the tilt angle θ from the measurement unit 51a and controls the driving of the right wheel drive motor 22 in the right wheel drive unit 21 and the left wheel drive motor 27 in the left wheel drive unit 25 to swing the vehicle body 11, so that the vehicle body 11 tilts at the target angle input by the input unit 55.

[0124] In this case, the reaction force estimation unit 57 and the determination unit 58 are omitted from the control device 50. Also, during the swinging of the vehicle body 11, there is a risk that the vehicle body 11 may not tilt to the desired target angle due to a shift in the position where the vehicle body 11 contacts the loading platform 100. In this case, the swinging control of the vehicle body 11 by the attitude control unit 51 becomes unstable, so it is preferable to prioritize the control that swings the vehicle body 11 to the target angle in the control by the attitude control unit 51.

[0125] ○The cargo handling mobile body 10 may be equipped with shock-absorbing parts at the contact points between the vehicle body 11 and the cargo handling platform 100. The shock-absorbing parts are made of, for example, low-rebound material. ○In the first embodiment, the cargo handling device 40 may be equipped with forks instead of the conveyor 45. In this configuration, the control method for the cargo handling mobile body 10 is such that the attitude control unit 51 swings the vehicle body 11 to support the vehicle body 11 in an inclined position on the cargo handling platform 100, and while the vehicle body 11 is supported on the cargo handling platform 100, the fork control unit drives the forks to support the load W on the forks or release the load W from the forks. In this configuration, because the vehicle body 11 is supported on the cargo handling platform 100, a reaction force is generated on the vehicle body 11 from the cargo handling platform 100. Receiving this reaction force, the vehicle body 11 maintains a stable posture despite being in an inclined position. Therefore, when handling cargo with the cargo handling device 40, even in situations where the center of gravity G fluctuates, such as when tilting up the forks to support the load W or tilting down the forks to release the load W, it is no longer necessary to stabilize the posture of the vehicle body 11 by swinging it with the posture control unit 51. As a result, the cargo handling mobile body 10 can perform cargo handling stably.

[0126] ○The cargo handling device 40 may be equipped with a seesaw that slides the load W by inclination. ○The drive unit may be an actuator other than a motor. [Note] The technical ideas that can be understood from the above embodiments and modifications are described below.

[0127] <Note 1> A method for controlling an inverted wheel type cargo handling mobile body for cargo handling, the cargo handling mobile body comprising: a pair of left and right drive wheels; a drive unit for driving the pair of left and right drive wheels; a body that swings in the front-rear direction about an axis coaxial with the axles of the pair of left and right drive wheels as a pivot point by the drive unit; a cargo handling device supported by the body for performing cargo handling on a load; a cargo handling device control unit for controlling the drive of the cargo handling device; and a posture control unit for controlling the drive of the drive unit to swing the body in the front-rear direction about the axis as a pivot point, the method for controlling a cargo handling mobile body comprising: the posture control unit swinging the body to support the body in an inclined position on a body support; and the cargo handling device control unit driving the cargo handling device to perform cargo handling while the body is supported on the body support.

[0128] <Note 2> The cargo handling mobile body comprises a restricting unit that restricts the rotation of the left and right pair of drive wheels, and a rotation restricting unit that controls the driving of the restricting unit, and the method for controlling the cargo handling mobile body according to Note 1, wherein the vehicle body is supported on the vehicle body support, and the rotation restricting unit drives the restricting unit to restrict the rotation of the left and right pair of drive wheels.

[0129] <Note 3> The cargo handling mobile body can assume a forward-tilting posture in which the upper end of the vehicle body is positioned in front of the lower end of the vehicle body, and the posture control unit swings the vehicle body into the forward-tilting posture and supports the vehicle body on the vehicle body support body, as described in Note 1 or Note 2.

[0130] <Note 4> The method for controlling a movable cargo handling body according to Note 3, wherein the cargo handling device control unit drives the cargo handling device to displace the load from the load handling position to a position different from the load handling position and to the retraction position on the vehicle body side, and the attitude control unit drives the drive unit to maintain the inverted position of the vehicle body in conjunction with the cargo handling device control unit driving the cargo handling device to displace the load from the load handling position to the retraction position.

[0131] <Note 5> A control method for a mobile cargo handling body according to any one of Notes 1 to 4, wherein the attitude control unit supports the vehicle body on the vehicle body support before the cargo handling device control unit drives the cargo handling device to perform cargo handling.

[0132] <Note 6> The method for controlling a cargo handling mobile body according to any one of Notes 1 to 5, wherein the cargo handling mobile body is equipped with a reaction force estimation unit that estimates the reaction force received by the vehicle body supported by the vehicle body support unit from the vehicle body support unit, and the attitude control unit swings the vehicle body based on the reaction force information obtained from the reaction force estimation unit.

[0133] FP Loading position BP Retraction position G Center of gravity L Axle X Front-rear direction 10 Loading / unloading mobile body 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 / unloading device 51 Attitude control unit and rotation restricting unit 57 Reaction force estimation unit 59, 61 Loading / unloading device control unit 90 Restricting unit 100 Loading platform as vehicle body support 110 Vehicle body support

Claims

1. A method for controlling an inverted wheel type cargo handling mobile body for cargo handling, the cargo handling mobile body comprising: a pair of left and right drive wheels; a drive unit for driving the pair of left and right drive wheels; a body that swings in the front-rear direction about an axis coaxial with the axles of the pair of left and right drive wheels as a pivot point by the drive unit; a cargo handling device supported by the body for performing cargo handling on a load; a cargo handling device control unit for controlling the drive of the cargo handling device; and a posture control unit for controlling the drive of the drive unit to swing the body in the front-rear direction about the axis as a pivot point, wherein the posture control unit swings the body to support the body in an inclined position on a body support; and with the body supported on the body support, the cargo handling device control unit drives the cargo handling device to perform cargo handling.

2. The method for controlling a cargo handling mobile body according to claim 1, comprising: a restricting unit for restricting the rotation of the left and right pair of drive wheels; and a rotation restricting unit for controlling the driving of the restricting unit, wherein the vehicle body is supported on the vehicle body support, and the rotation restricting unit drives the restricting unit to restrict the rotation of the left and right pair of drive wheels.

3. The method for controlling a cargo handling mobile body according to claim 1 or 2, wherein the cargo handling mobile body can assume a forward-tilting posture in which the upper end of the vehicle body is positioned in front of the lower end of the vehicle body, and the posture control unit swings the vehicle body into the forward-tilting posture and supports the vehicle body on the vehicle body support.

4. A method for controlling a mobile body for cargo handling according to claim 3, comprising: the cargo handling device control unit drives the cargo handling device to displace the load from the load handling position to a position different from the load handling position and to a retraction position on the vehicle body side; and the attitude control unit drives the drive unit to maintain the inverted position of the vehicle body in conjunction with the cargo handling device control unit driving the cargo handling device to displace the load from the load handling position to the retraction position.

5. A method for controlling a mobile cargo handling vehicle according to claim 1 or 2, wherein, before the cargo handling device control unit drives the cargo handling device to perform cargo handling, the attitude control unit causes the vehicle body to be supported by the vehicle body support.

6. A method for controlling a cargo handling mobile body according to claim 1 or 2, wherein the cargo handling mobile body includes a reaction force estimation unit that estimates the reaction force received by the vehicle body supported by the vehicle body support unit from the vehicle body support unit, and the attitude control unit swings the vehicle body based on the reaction force information obtained from the reaction force estimation unit.

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