Loading platform lifting device and work vehicle

Abstract

To provide a cargo bearing base elevation device and a work vehicle which can alleviate load such as safety confirmation regarding a vehicle rear side of an operator and operations.SOLUTION: A cargo bearing base elevation device 200 installed in a vehicle comprises: a cargo bearing base 202; a tilt cylinder 205 which lifts the cargo bearing base 202; and a controller 230 which controls the tilt cylinder 205. A notification part notifies when a sensor detects the cargo bearing base 202 is lifted to an elevated position that is a cargo floor height of the cargo bearing base 202.SELECTED DRAWING: Figure 33

Description

Technical Field

[0001] The present invention relates to a load platform lifting device and a work vehicle.

Background Art

[0002] Conventionally, as an example of a work vehicle, there is known a cargo handling vehicle including a vehicle body and a cargo handling device as a mounted object provided on the vehicle body, and configured such that a cargo handling target can be loaded and unloaded on and from the vehicle body by the cargo handling device. As this type of cargo handling vehicle, for example, there is a container cargo handling vehicle as described in Patent Document 1.

[0003] In the container cargo handling vehicle described in Patent Document 1, a container as a cargo handling target is loaded and unloaded between the vehicle body and the ground by the cargo handling device. The cargo handling device is composed of a dump frame, a cargo handling arm, a lift cylinder, a slide cylinder, a hydraulic circuit, etc., and the dump frame and the cargo handling arm are configured to operate as the lift cylinder and the slide cylinder expand and contract. The cargo handling arm has an L-shaped arm and a hook provided at the tip of the L-shaped arm, and the hook can be engaged with and disengaged from an engaged portion provided on the front wall of the container by the operation of the cargo handling arm.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In container handling vehicles as described above, when one person loads a container, they must first reverse the vehicle to a position where loading is possible (appropriate reverse position). However, determining how far to reverse often relies on experience, making it difficult for inexperienced beginners. Subsequently, the worker must operate the vehicle and extend / retract the lift cylinder and slide cylinder while checking the position of the hook on the handling arm and the engagement point on the container. As a result, safety checks behind the vehicle may be insufficient, and even if there are obstacles (people, objects, etc.) between the vehicle and the container, the worker may overlook them. Similarly, when one person unloads a container, even if there are obstacles within the planned unloading area, the worker may overlook them. Furthermore, the above-mentioned problems are also a concern when loading and unloading (loading and unloading) is performed by one person using handling vehicles other than container handling vehicles (for example, work vehicles equipped with a loading platform lifting device).

[0006] Furthermore, with conventional cargo handling vehicles, the cargo handling equipment would only operate while the remote control button was continuously pressed for safety reasons during loading and unloading of cargo. However, this meant that workers had to maintain a state of tension for extended periods while checking for safety and pressing the button, which was a cumbersome problem.

[0007] Furthermore, with conventional cargo handling vehicles, there was a problem in that it was difficult for beginners to operate the cargo handling equipment in the correct position, such as when moving the hook of the cargo handling arm of a container handling vehicle to the height of the part that engages with the container.

[0008] This invention has been made in consideration of the circumstances described above, and aims to provide a loading platform lifting device and a work vehicle that can reduce the burden on workers in checking for safety behind the vehicle and in operating the vehicle. [Means for solving the problem]

[0009] The present invention provides the following means for solving the above-mentioned problems. Specifically, the present invention is a work vehicle comprising a chassis and a body provided on the chassis, wherein the body allows loading and / or unloading of cargo onto the chassis, and the body comprises an object image acquisition unit that acquires data on the object image of surrounding objects and the distance to said object image, and a control unit that controls the drive actuator of the body based on the acquisition results of the object image acquisition unit. More specifically, the control unit calculates three-dimensional position information of the object based on measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, and / or based on an image of the object taken by the object image acquisition unit, and controls the drive actuator based on said three-dimensional position information.

[0010] According to the above configuration, the control unit can recognize the three-dimensional shape of objects around the vehicle (including cargo and obstacles) and the distance from the vehicle to those objects, based on the measurement light irradiated from the object image acquisition unit onto objects around the vehicle and reflected by the objects, and / or based on images taken from the object image acquisition unit of objects around the vehicle. As a result, the control unit can recognize the presence of obstacles between the vehicle and the cargo, allowing the vehicle to autonomously perform safety checks, such as checking the rear, which were previously done by the operator. Furthermore, it eliminates the need for operators to continuously operate buttons while checking for safety, which was previously cumbersome. Consequently, the burden on operators in checking for safety behind the vehicle and operating the vehicle can be reduced.

[0011] In the present invention, the vehicle body is equipped with a cargo handling device, the cargo handling device is provided on the vehicle chassis so as to be rotatable around a pivot axis in the vehicle width direction and has a hook at its tip that can be engaged with and disengaged from the engaged portion of the cargo to be handled, and comprises a cargo handling arm for loading and unloading the cargo to be handled between the vehicle chassis and the ground, and a drive actuator provided between the vehicle chassis and the cargo handling arm and arranged to rotate the cargo handling arm back and forth relative to the vehicle chassis, the control unit preferably calculates the position of the engaged portion of the cargo to be handled based on measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, or based on an image taken of the object by the object image acquisition unit, and controls the drive actuator based on the calculated position of the engaged portion to perform a loading operation in which the hook of the cargo handling arm engages with the engaged portion of the cargo to be handled.

[0012] With this configuration, even if the vehicle's stopping position is slightly off from the position suitable for loading the cargo, the control unit can autonomously operate the cargo handling arm to reliably engage the hook of the cargo handling arm with the engagement part of the cargo. Conventionally, operating such a cargo handling arm required reversing the vehicle while positioning the hook of the cargo handling arm in front of the engagement part of the cargo, which was not easy even for a skilled driver. However, with the above configuration, even if a novice is performing the loading operation alone, the hook of the cargo handling arm can be easily and reliably engaged with the engagement part of the cargo. Furthermore, since the cargo handling arm can be operated autonomously, the cargo handling device of the present invention can be applied to an autonomously driven vehicle chassis to reduce the number of people required for loading and unloading.

[0013] In the present invention, it is preferable that the control unit detects an obstacle above the vehicle based on the measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, or based on the image of the object captured by the object image acquisition unit, and determines whether the height of the detected obstacle is higher than the maximum height of the hook or the object to be handled when performing the loading operation.

[0014] With this configuration, it is easy to check whether there are any obstacles above the vehicle that could interfere with the loading arm or the object being loaded during the loading operation.

[0015] In the present invention, it is preferable that a side camera capable of photographing the rear of the vehicle is provided on the side of the chassis, and that the control unit determines whether or not the cargo to be handled is placed in a predetermined position on the chassis based on the image captured by the side camera during the loading operation.

[0016] This configuration ensures that the load to be handled is reliably placed in the designated position on the vehicle chassis during the loading operation of the loading arm, thereby improving the efficiency of the loading operation.

[0017] In the present invention, it is preferable to determine whether an obstacle of a certain area or more is detected between the vehicle and the cargo to be handled behind it, based on the measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, or based on the image of the object captured by the object image acquisition unit, when the vehicle is reversing or during loading operations.

[0018] With this configuration, when a vehicle is reversing, if an obstacle exceeding a certain area is detected between the vehicle and the cargo being handled from the rear view, the control unit can issue a signal to temporarily stop the vehicle's reversal. For example, if an operator is driving the vehicle, the control unit will notify the operator with an alarm. If the vehicle is an autonomous vehicle, the control unit will autonomously stop the vehicle's reversal. In this case, since the control unit's detection of obstacles is limited to areas exceeding a certain area, the control unit will not react to small obstacles that do not pose a substantial obstacle. As a result, collisions between the vehicle and actual obstacles can be avoided, and safety during vehicle reversal can be enhanced.

[0019] Furthermore, during the loading of cargo, if an obstacle exceeding a certain area is detected between the vehicle and the cargo from the rear view, the control unit can issue a signal to temporarily stop the operation of the cargo handling equipment. For example, if an operator is operating the cargo handling equipment, the control unit will notify the operator with an alarm. Also, when the loading operation of the cargo handling equipment is performed automatically, the control unit will autonomously stop the operation of the cargo handling equipment. In this case, the control unit's detection of obstacles is limited to areas exceeding a certain area, so the control unit will not react to small obstacles that do not pose a substantial obstacle. As a result, collisions between the cargo handling equipment and actual obstacles can be avoided, and the safety of the loading operation of cargo can be improved.

[0020] In the present invention, it is preferable that the control unit, when the vehicle is reversing or during loading operations, determines whether the inclination of the vehicle relative to the front of the object to be handled is greater than or equal to a predetermined value, and whether the lateral displacement of the vehicle relative to the center of the front of the object to be handled is greater than or equal to a predetermined value, based on the measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, or based on the image taken of the object by the object image acquisition unit. Furthermore, it is preferable that, when the vehicle is reversing, the control unit detects the distance to the front of the object to be handled, based on the measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, or based on the image taken of the object by the object image acquisition unit, and determines whether the vehicle has reversing to a position suitable for loading the object to be handled.

[0021] With these configurations, the vehicle's reverse guidance is performed based on measurement light that is projected from the object image acquisition unit onto objects around the vehicle and reflected by those objects, or based on images of objects around the vehicle taken by the object image acquisition unit. This makes it easy to move the vehicle to a position suitable for loading cargo onto the vehicle's bodywork (cargo handling equipment).

[0022] In the present invention, during the unloading operation, the control unit preferably determines whether an obstacle with an area equal to or larger than a certain area is detected in the planned unloading area of the loading / unloading target object behind the vehicle based on the measurement light irradiated onto the object from the object image acquisition unit and reflected by the object, or based on an image obtained by the object image acquisition unit capturing the object.

[0023] According to this configuration, during the unloading operation of the loading / unloading target object, if an obstacle with an area equal to or larger than a certain area is detected in the planned unloading area of the loading / unloading target object behind the vehicle when viewed from the rear of the vehicle, the control unit can issue a signal to temporarily stop the operation of the mounting device (loading / unloading device). For example, when an operator is operating the loading / unloading device, the control unit notifies the operator by an alarm. Also, when the unloading operation of the loading / unloading device is automatically performed, the control unit autonomously stops the operation of the loading / unloading device. At that time, since the detection of obstacles by the control unit is limited to an area equal to or larger than a certain area, the control unit can be made not to react to small obstacles that do not substantially become obstacles. As a result, it is possible to avoid the loading / unloading device from colliding with substantial obstacles, and the safety of the unloading operation of the loading / unloading target object can be enhanced.

[0024] In the present invention, a side camera capable of capturing the rear of the vehicle is provided on a side portion of the vehicle body, and when the control unit performs the unloading operation of the loading / unloading target object mounted on the vehicle body, based on the measurement light irradiated onto the object from the object image acquisition unit and reflected by the object and an image captured by the side camera, or based on an image captured by the object image acquisition unit capturing the object and an image captured by the side camera, it is preferable to determine whether there is an object approaching the planned unloading area of the loading / unloading target object.

[0025] According to this configuration, during the unloading operation of the loading / unloading target object by the mounting device (loading / unloading device), if there is an object approaching the loading / unloading target object, the unloading operation of the loading / unloading target object can be immediately stopped, and the safety during the unloading operation of the loading / unloading target object can be ensured.

[0026] The present invention also relates to a work vehicle including a vehicle body and a mounted object provided on the vehicle body, wherein the mounted object can load and / or unload a cargo object with respect to the vehicle body. The mounted object includes an object image acquisition unit configured to acquire data of an object image of a part of the mounted object that changes in form and the distance to the object image, and a control unit configured to control a drive actuator of the mounted object based on an acquisition result of the object image acquisition unit.

[0027] According to the above configuration, the object image acquisition unit acquires data of an object image of a part of the mounted object that changes in form and the distance to the object image, so that the control unit can recognize the three-dimensional shape of the part and the distance from the vehicle to the part. As a result, the control unit can recognize the change in form of the mounted object and operate the drive actuator, so that the mounted object can autonomously perform the safety confirmation and operation of the mounted object that were conventionally performed by an operator based on the change in form of the part. As a result, the burden of safety confirmation and operation of the mounted object by the operator can be reduced.

Effect of the Invention

[0028] According to the load receiving platform lifting device and the work vehicle of the present invention, the mounted object can autonomously perform safety confirmation at the rear or the like that was conventionally performed by an operator, and there is no need to continuously perform button operations while confirming the safety that was conventionally troublesome for the operator. Therefore, the burden of safety confirmation at the rear or the like of the vehicle and operation of the mounted object by the operator can be reduced.

Brief Description of the Drawings

[0029] [Figure 1] It is a side view showing a schematic configuration of a container handling vehicle according to an embodiment. [Figure 2] It is a perspective view showing a front wall portion of a container. [Figure 3] It is a perspective view showing a handling device of a container handling vehicle. [Figure 4] It is a plan view showing a handling device of a container handling vehicle. [Figure 5]This diagram shows a schematic configuration of the control system for a container handling vehicle. [Figure 6] This is a perspective view showing the installation locations of the sensor head and side camera on a container handling vehicle. [Figure 7] Figure 6 is a perspective view showing the sensor head and its surroundings. [Figure 8] Figure 6 is a perspective view showing the side camera and its surroundings. [Figure 9] Figure 6 is a diagram illustrating the switching of the illumination area of ​​the sensor head. [Figure 10] This flowchart shows the control process during container loading. [Figure 11] This flowchart shows the recognition process for the front wall of a container when reversing. [Figure 12] This graph shows the process of recognizing obstacles during the lifting process. [Figure 13] The process for recognizing obstacles above is being analyzed. [Figure 14] This flowchart shows the recognition process of the container's front wall during catching. [Figure 15] This flowchart shows the process of recognizing the front wall of the container during lifting. [Figure 16] This is a skeleton diagram of a cargo handling device, etc., showing the cargo handling arm in the resting position. [Figure 17] This is a skeleton diagram of a cargo handling device, etc., showing the cargo handling arm in a rearward-rotated position. [Figure 18] This is a flowchart for container unloading control. [Figure 19] This flowchart shows the process of recognizing obstacles within the planned unloading area. [Figure 20] This flowchart shows the process of recognizing obstacles using a side camera. [Figure 21] This is a schematic perspective view showing an example of a measurement point at the rear of a vehicle detected by a sensor head. [Figure 22] This is a perspective view showing an enlarged view of the measurement point area in Figure 21. [Figure 23] This is a front view showing an enlarged view of the measurement point area in Figure 21. [Figure 24] This is a plan view showing an enlarged view of the measurement point area in Figure 21. [Figure 25] This is a schematic perspective view showing an example of a measurement point at the rear of a vehicle when there are obstacles. [Figure 26] This is a schematic perspective view showing an example of a measurement point at the rear of a vehicle when the container is tilted. [Figure 27] This is a schematic plan view showing containers in a tilted position and containers shifted to the left or right. [Figure 28] This is a plan view showing the area where containers are scheduled to be unloaded and the laser irradiation area above the vehicle. [Figure 29] This figure shows an example of an image taken by a side camera. [Figure 30] This figure shows an example of the rear of a vehicle as seen from the sensor head. [Figure 31] This figure shows an example of the rear of a vehicle as seen from the sensor head. [Figure 32] This figure shows an example of the rear of a vehicle as seen from the sensor head. [Figure 33] This is a rear perspective view showing the schematic configuration of a vehicle equipped with a loading platform lifting device according to a modified example. [Figure 34] This is a side view showing the operating state of the loading platform lifting device. [Figure 35] This is a circuit diagram of the control device and hydraulic system installed in the loading platform lifting device. [Figure 36] This is a flowchart illustrating an example of the operation of a loading platform lifting device. [Figure 37] This is a perspective view of the main part showing the caster stopper of the loading platform, and a cross-sectional view of the same along the line X1-X1. [Figure 38] This is a flowchart illustrating an example of the operation of a loading platform lifting device. [Figure 39] This is a side view showing the schematic configuration of a modified feed transport vehicle. [Figure 40] This is a rear view of a feed transport vehicle. [Figure 41]This is a rear view showing how feed is being loaded into the silo by a feed transport truck. [Figure 42] This is a plan view showing the oscillating motion of the discharge unit. [Figure 43] A flowchart illustrating an example of the operation of a feed transport vehicle. [Modes for carrying out the invention]

[0030] Hereinafter, embodiments of the present invention applied to container handling vehicles will be described with reference to the drawings.

[0031] First, the basic configuration of the container handling vehicle 1 will be described with reference to Figures 1 to 4. The container handling vehicle 1 comprises a chassis and a loading / unloading device 3 as a frame mounted on the chassis and having a loading / unloading arm 34. The loading / unloading arm 34 is moved between the chassis and the rear of the chassis to load and unload containers 2, which are the objects to be handled, onto the chassis. In detail, the container handling vehicle 1 has a cab 12 on the front ends of a pair of chassis frames 11, 11 (chassis) that extend in the longitudinal direction of the vehicle. A subchassis 13 is provided on each chassis frame 11 behind the cab 12, extending in the longitudinal direction of the vehicle along the chassis frame 11. The front and rear ends of the left and right pair of subchassis 13, 13 are connected by a front cross member 15 and a rear cross member 17, respectively.

[0032] Containers 2 are mounted on chassis frames 11,11 via sub-chassis 13,13. Jacks 14 that can be extended toward the ground are provided at the rear ends of chassis frames 11,11. As shown by the dashed-dot line in Figure 1, the stability of the container handling vehicle 1 is enhanced by extending the jacks 14 to counteract the shift in the center of gravity toward the rear of the vehicle when the container 2 is loaded or unloaded by the loading / unloading device 3. In Figure 1, the dashed-dot line shows the state in which the container 2 is being loaded or unloaded between the chassis and the ground by the loading / unloading device 3, and the dashed-dot line shows the state after the container 2 has been lowered to the ground by the loading / unloading device 3 (before being loaded from the ground).

[0033] Container 2 is a roughly rectangular parallelepiped with an open top, and has a roughly rectangular bottom wall 2a at its bottom. This bottom wall 2a is surrounded by roughly rectangular front and rear walls 2b, 2c and roughly rectangular left and right side walls 2d, 2d. A pair of left and right main girders 21, 21 extending in the vehicle's longitudinal direction are provided on the underside of the bottom wall 2a of container 2. A pair of left and right legs 2f, 2f are provided at the front end of the underside of the bottom wall 2a, projecting downwards, and a pair of left and right wheels 2e, 2e are provided at the rear end of the underside of the bottom wall 2a. These wheels 2e, 2e are rotatable around an axis extending in the vehicle width direction. As shown in Figure 2, a round bar (engaged portion) 22 capable of engaging with the hook 38c of the cargo handling device 3 is provided at the upper part of the center in the vehicle width direction of the front wall 2b of container 2. This round bar 22 is a rod-shaped member extending in the vehicle width direction and is provided to project forward relative to the front wall 2b. The rear wall 2c of container 2 is supported at its upper end around an axis 23 that extends in the vehicle width direction at the upper rear ends of both left and right side walls 2d, 2d, and is capable of opening downwards to the rear. However, the rearward opening of the rear wall 2c of container 2 can be restricted by a rear wall securing device (not shown).

[0034] As shown in Figures 3 and 4, the cargo handling device 3 includes a pair of left and right dump frames 32, 32, a cargo handling arm 34, a pair of left and right lift cylinders 35, 36, a slide cylinder 39, a pair of left and right guide rollers 16, 16, and a hydraulic circuit (see Figure 5) which will be described later.

[0035] The dump frame 32 is rotatably connected at its rear end around a first pivot shaft 31 located in the vehicle width direction at the rear end position of the subchassis 13, thereby allowing it to tilt relative to the subchassis 13. The load handling arm 34 comprises a pivot frame 37 and a hook frame 38 attached to the pivot frame 37. The pivot frame 37 is formed in a tubular shape, and its base end is attached to the front end of the dump frame 32 via a second pivot shaft 33 parallel to the first pivot shaft 31, allowing it to rotate relative to the dump frame 32. The base end of the pivot frame 37 has an inclined upper end surface 37b that extends forward from the second pivot shaft 33.

[0036] The hook frame 38 is formed in an L-shape when viewed from the side and consists of an inner frame portion 38a, an upright frame portion 38b, and a hook 38c. The inner frame portion 38a is formed in a tubular shape, and its base end is slidably inserted in the front-rear direction through the opening at the tip of the rotating frame 37. The upright frame portion 38b is integrally formed with the inner frame portion 38a so as to bend upward from the tip of the inner frame portion 38a. The tip of this upright frame portion 38b is provided with a hook 38c that is formed in a roughly C-shape and can engage with and disengage from the round bar 22 of the container 2.

[0037] The slide cylinder 39 is a hydraulic cylinder and is inserted into and connected to the tubular portion of the rotating frame 37 and the inner frame portion 38a. When this slide cylinder 39 extends and retracts, the inner frame portion 38a slides back and forth relative to the rotating frame 37, causing the load handling arm 34 to extend and retract.

[0038] Between the rotating frame 37 and the dump frame 32, there is a securing device 40 that holds the rotating frame 37 in a nearly straight line relative to the dump frame 32 in a side view, thereby restricting relative rotation around the second pivot axis 33. This securing device 40 is configured to secure the load handling arm 34 to the dump frame 32 so that it cannot rotate relative to it when the slide cylinder 39 is extended, and to release the securing when the slide cylinder 39 is retracted.

[0039] The lift cylinders 35 and 36 are hydraulic cylinders and are connected between the left and right sides of the rotating frame 37 and the front cross member 15. With the securing device 40 released, the rotating frame 37 (loading arm 34) can be rotated in the front-rear direction around the second pivot shaft 33 by extending and retracting the lift cylinders 35 and 36. On the other hand, with the frame secured by the securing device 40, the rotating frame 37 and the dump frame 32 can be rotated together in the front-rear direction around the first pivot shaft 31 by extending and retracting the lift cylinders 35 and 36. Alternatively, an electric or hydraulic motor may be installed in place of the lift cylinders 35 and 36 at the second pivot shaft 33, and this motor may be used to rotate the rotating frame 37 (loading arm 34) in the front-rear direction.

[0040] The guide rollers 16, 16 are mounted at the rear end of the dump frames 32, 32 so as to be rotatable around an axis extending in the vehicle width direction. The guide rollers 16, 16 are provided to guide the container 2 smoothly in the front-rear direction when the main girder 21 of the container 2 is placed on it during loading and unloading of the container 2.

[0041] Next, the control system of the container handling vehicle 1 will be described with reference to Figure 5. This control system includes a hydraulic circuit for operating the handling device 3 of the container handling vehicle 1, and a control unit 70 for controlling the switching operation of the switching valves 48 and 49 provided in this hydraulic circuit.

[0042] In the hydraulic circuit shown in Figure 5, the hydraulic pump 43, which is the hydraulic power source, is driven by an engine (not shown), and pumps hydraulic fluid from the oil tank 44 through the suction pipe 43a and supplies pressurized oil from the discharge port. The discharge port of the hydraulic pump 43 is connected to the upstream end of the main oil passage 45 via the pressure port PP of the valve unit 4. In this main oil passage 45, a lift cylinder switching valve 48 that switches the extension and retraction movements of the lift cylinders 35 and 36, and a slide cylinder switching valve 49 that switches the extension and retraction movements of the slide cylinder 39 are installed in series from the upstream side.

[0043] The downstream end of the main oil passage 45 is connected to the tank port T of the valve unit 4, and the drain pipe 50 is connected to this tank port T. A filter 51 is installed midway along the drain pipe 50. Each of the switching valves 48 and 49 consists of a 6-port, 3-position electromagnetic pilot switching valve, and when all of them are in the neutral position (de-energized state; position shown in Figure 5), the entire amount of pressurized oil supplied by the hydraulic pump 43 is returned to the oil tank 44 via the main oil passage 45 and the drain pipe 50.

[0044] One end of the first to third branch oil passages 53 to 55 are connected to the main oil passage 45 between the hydraulic pump 43 and the switching valve 48. The other end of the first branch oil passage 53 is connected near the downstream end of the main oil passage 45, and a relief valve 56 is provided in the middle of the first branch oil passage 53. A pressure reducing valve 57 is provided at the other end of the second branch oil passage 54, so that pressurized oil reduced to a predetermined pilot pressure is supplied to the pilot oil passage 58. Pilot pressure is supplied to each switching valve 48, 49 through this pilot oil passage 58. The other end of the third branch oil passage 55 is connected to a pressure sensor (not shown) through the output pressure port PP'. In addition, a sequence valve 60 is installed in the main oil passage 45, which is provided to raise the pilot pressure immediately after the hydraulic pump 43 is driven. Each port of each switching valve 48, 49 is connected to the hydraulic ports A1, A2, B1, B2 for actuators of the valve unit 4 and to the main oil passage 45.

[0045] The bottom ports of each lift cylinder 35 and 36 are connected to predetermined ports of the switching valve 48 via hydraulic port A1. The rod ports of each lift cylinder 35 and 36 are connected to predetermined ports of the switching valve 48 via hydraulic port B1. In addition, to maintain the back pressure of each lift cylinder 35 and 36, a counterbalance valve 61 is provided on the oil passage connecting the lift cylinders 35 and 36 to the respective hydraulic ports A1 and B1.

[0046] The bottom port of the slide cylinder 39 is connected to a predetermined port of the slide cylinder switching valve 49 via hydraulic port A2. The rod port of the slide cylinder 39 is connected to a predetermined port of the slide cylinder switching valve 49 via hydraulic port B2. A pilot check valve 65 is also provided in the oil passage connecting the bottom port of the slide cylinder 39 and hydraulic port A2.

[0047] The switching operation of the switching valves 48 and 49 in the hydraulic circuit with the above configuration is controlled by the control unit 70. The control unit 70 is connected to a lift cylinder stroke sensor 72 that detects the stroke amount of the lift cylinder 36 (the rotational position of the cargo handling arm 34 when the securing device 40 is released) and a slide cylinder stroke sensor 73 that detects the stroke amount of the slide cylinder 39 (the sliding position of the cargo handling arm 34).

[0048] As shown in Figure 5, the remote controller 74 is equipped with a detachment switch 74b, a tilt switch 74e, an automatic loading button 74f, and an automatic unloading button 74g. The remote controller 74 is located around the driver's seat inside the cab 12, allowing the operator to operate the cargo handling device 3 while seated in the driver's seat. When one side (upper in Figure 5) of the detachment switch 74b is pressed, the container 2 is lifted according to a preset sequence control while the operation is in progress. When the other side (lower in Figure 5) of the detachment switch 74d is pressed, the container 2 is lowered according to the sequence control while the operation is in progress. The tilt switch 74e is a switch for tilting the container 2 by extending and retracting the lift cylinders 35 and 36 while the container is secured by the securing device 40. The automatic loading button 74f and the automatic unloading button 74g will be described later. Although not shown in Figure 5, a PTO switch is provided inside the cab 12 to switch between outputting engine power to the drive side and outputting it to the hydraulic pump 43 side.

[0049] For example, wire-type stroke sensors can be used as stroke sensors 72 and 73, but cylinder-integrated stroke sensors may also be used. As a wire-type stroke sensor, for example, one can be used that has a rotating drum and a main body 721, 731 housing an encoder that converts the amount of rotation of the rotating drum into an electrical signal and inputs it to the control unit 70, and wires 722, 732 that are wound around the rotating drum so as to be able to be fed out. The main body 721, 731 are fixed to the tube side of the lift cylinder 36 and the slide cylinder 39, respectively, and the ends of the wires 722, 732 are fixed to the ends of the lift cylinder 36 and the slide cylinder 39. The rotating drum is biased to rotate in one direction in order to apply appropriate tension to the wires 722, 732.

[0050] In a container handling vehicle 1 configured in this way, there is a problem in that it is difficult for workers inside the cab 12 to directly visually check the situation behind the vehicle when loading or unloading containers 2. Therefore, in a container handling vehicle 1 to which the present invention is applied, the cargo handling device 3, which is a mounted component, is equipped with a sensor head 8 as an object image acquisition unit, side cameras 9L and 9R, a laser control unit 8a that controls the sensor head 8, and an image processing unit 9a that processes image data acquired by the cameras 9L and 9R.

[0051] As shown in Figures 6 and 7, the sensor head 8 is fixed to the rear end of the container handling vehicle 1, more specifically, to the center of the rear surface in the vehicle width direction of the cross frame 11a connected to the rear ends of the chassis frames 11, 11. The sensor head 8 acquires data on object images of objects around the vehicle and the distance to said object images. The sensor head 8 is configured to irradiate laser light as measurement light toward a predetermined area behind or above the vehicle, and to receive laser light (reflected light) reflected by objects. An example of a measurement point behind the vehicle detected by the sensor head 8 is shown in Figures 21 to 26. It is preferable that the sensor head 8 is covered with a cover member (not shown) so as not to interfere with the irradiation of laser light in order to protect it from contact with objects and the adhesion of dirt, etc. It is also preferable that the sensor head 8 is attached to the cross frame 11a via a cushioning member capable of absorbing the impact when objects come into contact with it.

[0052] As shown in Figure 5, the sensor head 8 comprises a laser light source 81, a collimating lens 82, a polygon mirror 83, a rocking mirror 84, a focusing lens 85, a light receiver 86, a main scanning motor 87, a sub-scanning motor 88, a main scanning motor driver 89, and a sub-scanning motor driver 90. Furthermore, as shown in Figure 7, the sensor head 8 is rotatably mounted around an axis 8c extending along the vehicle width direction by an electric motor 8b, allowing the laser beam irradiation angle (direction) to be changed. The sensor head 8 can switch between a first position, where the laser beam is directed toward the laser irradiation area W1 at the rear of the vehicle (see Figure 9(a)), and a second position, where the laser beam is directed toward the laser irradiation area W2 above the vehicle (see Figure 9(b)). The sensor head 8 and the electric motor 8b are connected to the laser control unit 8a.

[0053] The sensor head 8 irradiates pulsed laser light (laser pulses) toward the laser irradiation areas W1 and W2 according to the control of the laser control unit 8a. When the sensor head 8 irradiates laser light toward the laser irradiation area W1 at the rear of the vehicle, it irradiates laser pulses as measurement light along the main scanning direction and sub-scanning direction set in the laser irradiation area W1. The sensor head 8 irradiates one line of laser pulses along the main scanning direction, then moves the irradiation position of the laser pulses by a certain pitch along the sub-scanning direction perpendicular to the main scanning direction, and then irradiates another line of laser pulses along the main scanning direction. This operation is repeated, thereby irradiating the entire laser irradiation area W1 with laser pulses. The sensor head 8 also sequentially receives the reflected light of the laser pulses returning from objects in the laser irradiation area W1 and outputs a received signal indicating the received intensity of the reflected light to the laser control unit 8a.

[0054] On the other hand, when irradiating laser light towards the laser irradiation area W2 above the vehicle, the sensor head 8 irradiates laser pulses as measurement light along the main scanning direction and sub-scanning direction set in the laser irradiation area W2. The sensor head 8 irradiates one line of laser pulses along the main scanning direction, then moves the irradiation position of the laser pulses by a certain pitch along the sub-scanning direction perpendicular to the main scanning direction, and then irradiates another line of laser pulses along the main scanning direction. This operation is repeated, thereby irradiating the entire laser irradiation area W2. The sensor head 8 also sequentially receives the reflected light of the laser pulses returning from objects in the laser irradiation area W2 and outputs a received signal indicating the received intensity of the reflected light to the laser control unit 8a.

[0055] The laser light source 81 emits laser pulses with a constant wavelength to the collimating lens 82 according to the control of the laser control unit 8a, and outputs a timing signal indicating the repetition timing of the laser pulses to the laser control unit 8a. The collimating lens 82 converts the laser pulses incident from the laser light source 81 into parallel light and emits it to the polygon mirror 83. The polygon mirror 83 is a polyhedron having multiple (e.g., three) mirror surfaces for reflecting the laser pulses. The rotation axis of the polygon mirror 83 is coupled to the rotation axis of the main scanning motor 87. The rotation of the main scanning motor 87 causes the polygon mirror 83 to rotate in the direction indicated by the arrow in Figure 5. Due to the rotation of the polygon mirror 83, the laser pulses incident from the collimating lens 82 to the polygon mirror 83 are reflected toward the oscillating mirror 84 and scanned along the main scanning direction.

[0056] The oscillating mirror 84 is a flat plate-shaped mirror that is mounted to swing around an axis perpendicular to the rotation axis of the polygon mirror 83. The rotation axis of the oscillating mirror 84 is coupled to the rotation axis of the sub-scanning motor 88. The rotation of the sub-scanning motor 88 causes the oscillating mirror 84 to swing in the direction indicated by the arrow in Figure 4. Due to the swinging of the oscillating mirror 84, the laser pulses incident on the oscillating mirror 84 from the polygon mirror 83 are reflected (emitted) toward the outside of the sensor head 8 (i.e., the laser irradiation areas W1, W2) and are scanned along the sub-scanning direction.

[0057] Specifically, the horizontal angle β of the laser pulses irradiated from the sensor head 8 onto the laser irradiation areas W1 and W2 (the angle between the main scanning direction and the irradiation direction of the laser pulses when the laser irradiation areas W1 and W2 are viewed from above; see Figure 4) is controlled by the rotation of the polygon mirror 83. In addition, the vertical angle α of the laser pulses irradiated from the sensor head 8 onto the laser irradiation areas W1 and W2 (the angle between the sub-scanning direction and the irradiation direction of the laser pulses when the laser irradiation areas W1 and W2 are viewed from the side; see Figures 9(a) and (b)) is controlled by the oscillation of the oscillating mirror 84.

[0058] By controlling the horizontal angle β and vertical angle α as described above, the laser pulse is scanned along the main scanning direction and the sub-scanning direction, and as a result, the laser pulse is irradiated over the entire area of ​​the laser irradiation regions W1 and W2. The reflected light of the laser pulse that is reflected back is incident on the focusing lens 85 via the oscillating mirror 84 and the polygon mirror 83. The focusing lens 85 focuses the reflected light of the laser pulse onto the receiving surface of the photodetector 86. The photodetector 86 performs photoelectric conversion of the reflected light of the laser pulse focused by the focusing lens 85 and outputs a receiving signal indicating the reception of the reflected light to the laser control unit 8a.

[0059] The main scanning motor 87 is a motor that rotates in response to a drive signal input from the main scanning motor driver 89. The main scanning motor driver 89 generates a drive signal to rotate the main scanning motor 87 at a constant speed and outputs it to the main scanning motor 87, in accordance with the control of the laser control unit 8a. As described above, the polygon mirror 83 rotates due to the rotation of the main scanning motor 87. The sub-scanning motor 88 is a motor that rotates in response to a drive signal input from the sub-scanning motor driver 90. The sub-scanning motor driver 90 generates a drive signal to oscillate the oscillating mirror 84 at a predetermined angle and timing and outputs it to the sub-scanning motor 88, in accordance with the control of the laser control unit 8a. As described above, the oscillating mirror 84 oscillates due to the rotation of the sub-scanning motor 88.

[0060] Here, when laser light is irradiated from the sensor head 8 toward the rear of the vehicle (see Figure 9(a)), the laser irradiation area W1 of the laser light (laser pulse) irradiated from the sensor head 8 has a vertical angle α (see Figure 9(a)) in the range of, for example, 60° to 135°, and a horizontal angle β (see Figure 4) in the range of, for example, 0° to 180°. Specifically, along the main scanning direction, laser pulses are irradiated at a constant pitch (for example, 0.3° to 2°) with a horizontal angle β in the range of 0° to 180°. After the laser pulse is irradiated along the main scanning direction for one line (with a horizontal angle β in the range of 0° to 180°), the irradiation position of the laser pulse is moved along the sub-scanning direction by a constant pitch (for example, 1.5° to 3°). In this way, by repeating the operation of irradiating the laser pulse for one line along the main scanning direction and then moving the irradiation position of the laser pulse along the sub-scanning direction, the laser pulse is irradiated over the entire area of ​​the laser irradiation area W1. In this embodiment, laser pulses in the sub-scanning direction are irradiated at 1.5° intervals within a vertical angle α range of 60° to 135°. Thus, the laser control unit 8a controls the operation of the sensor head 8 (i.e., the vertical angle α and horizontal angle β of the laser pulses) by controlling the laser light source 81, the main scanning motor driver 89, and the sub-scanning motor driver 90. Note that the range and pitch of the horizontal angle β and the range and pitch of the vertical angle α described above are examples and can be appropriately changed depending on the sensing accuracy, operating speed, and installation location of the sensor head 8.

[0061] Similarly, when laser light is emitted from the sensor head 8 towards the vehicle above (see Figure 9(b)), the laser irradiation area W2 of the laser light emitted from the sensor head 8 has a vertical angle α (see Figure 9(b)) in the range of, for example, 135° to 210°, and a horizontal angle β (see Figure 4) in the range of, for example, 0° to 180°. Specifically, laser pulses are emitted along the main scanning direction at a constant pitch (for example, 0.3° to 2°) with a horizontal angle β in the range of 0° to 180°. After the laser pulse has been emitted for one line (horizontal angle β in the range of 0° to 180°) along the main scanning direction, the irradiation position of the laser pulse is moved by a constant pitch (for example, 1.5° to 3°) along the sub-scanning direction. In this way, by repeating the operation of irradiating one line of laser pulse along the main scanning direction and then moving the irradiation position of the laser pulse along the sub-scanning direction, the laser pulse is emitted over the entire laser irradiation area W2. In this embodiment, the laser pulses in the sub-scanning direction are irradiated at 1.5° intervals within a vertical angle α range of 60° to 135°.

[0062] When the area behind the vehicle is scanned by the laser pulse emitted from the sensor head 8, if an object (for example, container 2 in Figure 9(a)) is present in the laser irradiation area W1, the laser pulse is reflected by that object. When this reflected light of the laser pulse is incident on the sensor head 8, the photodetector 86 performs photoelectric conversion of the reflected light of the laser pulse and outputs a received signal to the laser control unit 8a. The laser control unit 8a calculates the distance D between the sensor head 8 and the measurement point P (reflection position of the laser pulse) on the object based on the time difference (delay time) between the timing signal input from the laser light source 81 and the received signal input from the photodetector 86. In addition to the distance D, the laser control unit 8a then acquires the vertical angle α and horizontal angle β of the laser pulse when the laser pulse is irradiated onto the measurement point P on the object as 3D polar coordinate data (distance D, vertical angle α, horizontal angle β), which are the position information of the measurement point P. In this way, by irradiating the entire laser irradiation area W1 with laser pulses, the received signal of the reflected light of the laser pulses is input to the laser control unit 8a, and 3D polar coordinate data for each measurement point P is acquired.

[0063] Furthermore, the laser control unit 8a converts the acquired 3D polar coordinate data of each measurement point P into XYZ Cartesian coordinate data (3D Cartesian coordinate data). At this time, the X coordinate Px of the XYZ Cartesian coordinate data becomes [D·sinα·cosβ], the Y coordinate Py becomes [D·sinα·sinβ], and the Z coordinate Pz becomes [Z0-D·cosα] (Z0 is the height of the sensor head 8 from the ground, which is set to, for example, 500mm to 600mm). The XYZ Cartesian coordinate data (Px, Py, Pz) obtained in this way corresponds to the position on the surface of the object where the laser pulse was irradiated (reflected). In this case, the XYZ Cartesian coordinate data (Px, Py, Pz) of each measurement point P is calculated with the coordinates of the ground directly below the sensor head 8 as the origin (0,0,0). Such coordinate transformations are performed for the 3D polar coordinate data of each measurement point P. Then, the XYZ Cartesian coordinate data (Px, Py, Pz), which is the position information of each measurement point P, is output from the laser control unit 8a to the control unit 70.

[0064] As shown in Figures 6 and 8, the side cameras 9L and 9R are fixed to support members 91, 91 attached to the outer sides of each sub-chassis 13, 13. The optical axes of the imaging lenses 92, 92 of the side cameras 9L and 9R are oriented rearward along the horizontal direction. One side camera 9L is mounted to photograph a predetermined range to the left rear of the vehicle (see Figure 29), and the other side camera 9R is mounted to photograph a predetermined range to the right rear of the vehicle. More specifically, side camera 9L can photograph the left main girder 21 of the container 2, the left guide roller 16, and the left side of the container 2 (container handling vehicle 1), while side camera 9R can photograph the right main girder 21 of the container 2, the right guide roller 16, and the right side of the container 2 (container handling vehicle 1). The image processing unit 9a performs known image processing on the image signals acquired by the side cameras 9L and 9R, and outputs the processed image signals to the control unit 70.

[0065] The control unit 70 controls the switching of the switching valves 48 and 49 for loading and unloading the container 2, and controls the operation of the buzzer 74a, based on the output signals from the remote controller 74, the laser control unit 8a, the image processing unit 9a, and the sensors 72 and 73. The control unit 70 also has a memory 70a, which stores various data (feature data, judgment thresholds, etc.) used for automatic loading control performed based on the operation of the automatic loading button 74f, and various data used for automatic unloading control performed based on the operation of the automatic unloading button 74g.

[0066] Next, the operation of the container handling vehicle 1 will be described. The container handling vehicle 1 is capable of loading containers 2 using the handling device 3, unloading the loaded containers 2, and tilting the loaded containers 2. The loading operation involves first reversing the vehicle toward the front wall of the container 2 and stopping at the appropriate reversal position, then rotating the handling arm 34 backward to hook the hook 38c onto the round bar 22, and then rotating the handling arm 34 forward to load the container 2. The unloading operation involves sliding the loaded container 2 (handling arm 34) backward and then rotating it backward to lower it to the ground. The tilt operation involves tilting the loaded container 2 together with the dump frame 32 and handling arm 34 using the lift cylinders 35 and 36 to discharge the contents inside the container 2.

[0067] Loading is performed by operating the detachment switch 74b (manual loading) or the automatic loading button 74f (automatic loading). Unloading is performed by operating the detachment switch 74b (manual unloading) or the automatic unloading button 74g (automatic unloading). Tilt operation is performed by operating the tilt switch 74e. The container handling vehicle 1 to which the present invention is applied is characterized by its automatic loading and automatic unloading control, and these controls will be described below.

[0068] The control during automatic loading will be explained with reference to Figures 10-15. Figure 10 shows the overall flow of automatic loading (steps S1-S40), Figure 11 shows the detailed flow of step S5, Figure 12 shows the detailed flows of steps S8, S25, and S32, Figure 13 shows the detailed flow of step S18, Figure 14 shows the detailed flow of step S21, and Figure 15 shows the detailed flow of step S31.

[0069] In the flowchart of Figure 10, steps S1 to S14 are for safety confirmation and control of the reverse guide when the vehicle is reversing, and steps S15 to S40 are for automatic loading control of container 2. The safety confirmation and control of the reverse guide when the vehicle is reversing in steps S1 to S14 are performed as preparatory control for the automatic loading control of container 2 in steps S15 to S40. For convenience, these controls are described as a series of controls, but the safety confirmation and control of the reverse guide when the vehicle is reversing in steps S1 to S14 and the automatic loading control of container 2 in steps S15 to S40 may be performed separately.

[0070] First, in step S1, the system remains in a standby state until the ACC power is turned on, or in other words, until power corresponding to the ACC power being turned on is input to the control unit 70. Then, once power is input, in step S2, the control unit 70, the laser control unit 8a, and the image processing unit 9a perform initialization processing, after which the control unit 70 rotates the sensor head 8 backward (to the direction in which laser pulses are irradiated onto the laser irradiation area W1), and proceeds to step S3.

[0071] In step S3, the control unit 70 determines whether or not a reverse signal based on the operation of the container handling vehicle 1 has been input to the control unit 70. If a reverse signal has been input, the process proceeds to step S4; if no reverse signal has been input, the process waits until a reverse signal is input. Then, in step S4, after the scanning of the sensor head 8 begins, the process proceeds to step S5. It is preferable that the vehicle be reversed with the handling arm 34 rotated to the loading completion position (see Figure 6) in order to prevent the laser pulse emitted from the sensor head 8 from being reflected by the handling arm 34.

[0072] The recognition process of the front wall 2b of container 2 in step S5 will be explained with reference to Figure 11. First, in step S5a, the sensor head 8 is driven by the laser control unit 8a and a laser pulse is irradiated onto the laser irradiation area W1 at the rear of the vehicle. Then, for all measurement points P in the laser irradiation area W1, the laser control unit 8a acquires 3D polar coordinate data (D, α, β), which is the 3D position information of each measurement point P. In step S5b, the 3D polar coordinate data of each measurement point P is converted into XYZ orthogonal coordinate data (Px, Py, Pz). The converted XYZ orthogonal coordinate data (Px, Py, Pz) of each measurement point P is sent to the control unit 70.

[0073] Then, in step S5c, the control unit 70 extracts data from the XYZ Cartesian coordinate data (Px, Py, Pz) obtained in step S5b in which the X coordinate Px falls within a predetermined horizontal search range as data to be recognized. Since the vehicle is often reversed towards the container 2 from a position about twice the vehicle's front-to-rear length, the horizontal search range can be set to a value that is, for example, the distance from the appropriate reversing position to the front wall 2b plus twice the vehicle's front-to-rear length. If the horizontal search range is set to a value that is too large, objects behind the container 2 (objects that do not hinder the vehicle's reversal) will also be extracted, while if the horizontal search range is set to a value that is too small, the front wall 2b of the container 2 will not be extracted, so it is preferable to set it as described above.

[0074] The recognition target data extracted in step S5c will be as shown in Figures 21 to 24 if there are no obstacles between the vehicle and the container 2, and as shown in Figure 25 if there are obstacles between the vehicle and the container 2. Furthermore, if the container 2 is tilted, it will be as shown in Figure 26. In Figures 21 to 26, each extracted measurement point P is indicated by a "+" mark, and in Figures 22 to 24, only each extracted measurement point P is shown. The shape of each measurement point P (group of measurement points) as shown in Figures 22 to 26 corresponds to the shape of the object recognized by the control unit 70. Note that in Figures 21, 25, and 26, a virtual wall 101 is placed behind the vehicle to make it easier to understand what the rear of the vehicle looks like (see Figure 29).

[0075] Next, in step S5d, from the recognition target data obtained in step S5c, a set of adjacent measurement points is orthogonally projected onto the YZ plane and the XY plane, and extracted as two-dimensional object images A and A', respectively. After extracting object images A and A', the process proceeds to step S5e. Specifically, from the XYZ Cartesian coordinate data (Px, Py, Pz) of each measurement point P (group of measurement points), data of measurement points where the Y coordinate Py and Z coordinate Pz are both adjacent is extracted, and all the extracted data from the group of measurement points is projected (orthogonally projected) onto the YZ plane, which is the reference plane (all X coordinates Px of the extracted group of measurement points are set to 0). Then, the data of the group of measurement points projected onto the YZ plane is extracted as a two-dimensional object image A. Similarly, from the XYZ Cartesian coordinate data (Px, Py, Pz) of each measurement point P (measurement point cloud), data is extracted for measurement point clouds where both the X coordinate Px and Y coordinate Py are adjacent. All the extracted measurement point cloud data is then projected (orthogonal projection) onto the XY plane, which serves as the reference plane (all Z coordinates Pz of the extracted measurement point clouds are set to 0). Finally, the measurement point cloud data projected onto the XY plane is extracted as a 2D object image A'.

[0076] In step S5e, the total area A1 of the object image A is compared with the front wall determination threshold value A2. When the total area A1 is greater than or equal to the front wall determination threshold value A2 (A1 ≥ A2), the process proceeds to step S5f. On the other hand, when the total area A1 is less than the front wall determination threshold value A2 (A1 < A2), the process proceeds to step S5g. The total area A1 of the object image A can be calculated according to, for example, the number of '+' marks shown in FIG. 22. For example, when the number of '+' marks included in the object image A is 100, the total area A1 of the object image A is calculated as 100. The front wall determination threshold value A2 is a value corresponding to the area of the front wall 2b in the YZ plane and is stored in the memory 70a of the control unit 70.

[0077] In step S5f, by comparing the object image A with the front wall feature data, the degree of coincidence of the feature portions between the two is analyzed. The front wall feature data is data created by extracting in advance the features of the shape and size of the front wall 2b and is stored in the memory 70a of the control unit 70. As the front wall feature data, for example, data such as the shape of the front wall 2b that is substantially rectangular and the lower corners of which are cut diagonally, or the shape of the front wall 2b provided with the round bar 22 at the upper part in the center of the vehicle width direction can be used.

[0078] In step S5h, based on the analysis result of step S5f, when it is determined that the degree of coincidence of the feature portions between the object image A and the front wall feature data is large and the object image A has the feature portion of the front wall 2b, the process proceeds to step S5i. On the other hand, when it is determined that the degree of coincidence of the feature portions between the object image A and the front wall feature data is small and it does not have the feature portion, the process proceeds to step S5g.

[0079] Then, in step S5i, the object image A is recognized as the front wall 2b, and the process proceeds to the next step S5j. On the other hand, in step S5g, the object image A is recognized as not being the front wall 2b, and the process proceeds to the next step S5j.

[0080] In step S5j, the average inclination (lateral inclination γ1) of the object (a set of adjacent measurement points) with respect to the Y-axis is calculated using the object image A' extracted in step S5d, and the process proceeds to step S5k. The lateral inclination γ1 of object image A' is calculated as the angle of the straight line L1 connecting the left and right ends of the front wall 2b of container 2 with respect to the Y-axis, as shown in Figure 27(a), for example. The calculation result in step S5j is used in step S9, described later, to determine the lateral inclination γ of the front wall 2b with respect to the vehicle.

[0081] Then, in step S5k, it is determined whether the analysis (analysis of whether it corresponds to the front wall 2b) has been completed for all sets (object images A, A'). If the analysis has been completed, step S5 is terminated and the process proceeds to step S6 in Figure 10. On the other hand, if the analysis has not been completed, the process returns to step S5e and is repeated until it is determined that the analysis has been completed.

[0082] In step S6 of Figure 10, the recognition history of the front wall 2b in step S5i of Figure 11 is checked, and if there is a recognition history, the process proceeds to step S7. On the other hand, if there is no recognition history, the process returns to step 5 and is repeated until it is determined that there is a recognition history. Then, in step S7, the control unit 70 outputs an activation signal to the buzzer 74a to generate an audio signal announcing the detection of container 2, and then proceeds to step S8.

[0083] The obstacle recognition process in step S8 will be explained with reference to Figure 12. First, step S8a is the same as step S5a in Figure 11, and step S8b is the same as step S5b in Figure 11, so the explanation here will be omitted. In step S8c, from the XYZ Cartesian coordinate data (Px, Py, Pz) obtained in step S8b, data in which the X coordinate is smaller than the front wall 2b (closer to the vehicle) is extracted and used as the data to be recognized, and the process proceeds to step S8d.

[0084] Next, in step S8d, in the same manner as step S5d in FIG. 11, among the recognition target data obtained in step S8c, the set of adjacent measurement points is orthogonally projected onto the YZ plane and extracted as a two-dimensional object image B (see, for example, FIG. 25). After extracting the object image B, the process proceeds to step S8e.

[0085] In step S8e, the total area B1 of the object image B is compared with an obstacle determination threshold B2. If the total area B1 is greater than or equal to the obstacle determination threshold B2 (B1 ≥ B2), the process proceeds to step S8f. On the other hand, if the total area B1 is less than the obstacle determination threshold B2 (B1 < B2), the process proceeds to step S8g. The total area B1 of the object image B can be calculated, for example, according to the number of '+' marks shown in FIG. 25 in the same manner as step S5e in FIG. 11. The obstacle determination threshold B2 is set to a value that can exclude small objects (such as dead leaves, etc.) that do not cause an obstacle even if they come into contact with the vehicle, and is stored in the memory 70a of the control unit 70.

[0086] Then, in step S8f, the object image B is recognized as an obstacle, and the process proceeds to the next step S8h. On the other hand, in step S8g, the object image B is recognized as not being an obstacle, and the process proceeds to the next step S8h. In step S8h, it is determined whether analysis (analysis of whether it is an obstacle or not) has been completed for all sets (object images B). If the analysis has been completed, this step S8 ends. On the other hand, if the analysis has not been completed, the process returns to step S8e and is repeated until it is determined that the analysis has been completed.

[0087] In step S8f of Figure 12, if it is determined that there are no obstacles (no obstacles exceeding a certain area between the vehicle and container 2), the process proceeds from step S8 to step S9 in Figure 10. On the other hand, if it is determined that there are obstacles, the process proceeds from step S8 to step S12 in Figure 10. The reason for proceeding from step S8 to step S12 is that there is a risk of the vehicle coming into contact with the obstacle if it continues to reverse. In step S12, a reverse warning is issued from the buzzer 74a to prompt the operator to stop the vehicle from reversing. After issuing the reverse warning in step S12, the process returns to step 8 to determine the presence or absence of obstacles again.

[0088] In step S9, the calculation result from step S5j in Figure 11, specifically the lateral inclination γ1 of the front wall 2b relative to the vehicle (see Figure 27(a)), is compared with the upper limit value γ2 of the inclination that allows the container 2 to be loaded. If the inclination γ1 calculated in step S5j is greater than or equal to the upper limit value γ2 (γ1≧γ2), the process proceeds to step S12. On the other hand, if the inclination γ1 calculated in step S5j is less than the upper limit value γ2 (γ1<γ2), the process proceeds to step S10. The reason for proceeding from step S9 to step S12 is that the lateral inclination γ1 of the front wall 2b relative to the vehicle is large, and loading the container 2 would be difficult even if the vehicle were reversed in this state. In this case, in step S12, a reverse warning is issued from the buzzer 74a to prompt the operator to correct the inclination.

[0089] In step S10, the positional misalignment δ in the vehicle width direction between the vehicle and the container 2 (see Figure 27(b)) is determined. This is because even if the lateral tilt γ1 of the front wall 2b relative to the vehicle described above is small (step S9), if the positional misalignment δ in the vehicle width direction is large, it becomes difficult to attach the hook 38c to the round bar 22. In step S10, for example as shown in Figure 27(b), the midpoint position δ1 in the Y direction of the front wall 2b is calculated with respect to the Y coordinate, with the vehicle (position of the sensor head 8) as the origin. This midpoint position δ1 is compared with the allowable misalignment amount δ2 stored in memory 70a, and if the midpoint position δ1 in the Y direction of the front wall 2b is greater than or equal to the allowable misalignment amount δ2 (|δ1|≧δ2), the process proceeds to step S12. On the other hand, if the midpoint position δ1 in the Y direction of the front wall 2b is less than the allowable misalignment amount δ2 (|δ1|<δ2), the process proceeds to step S11.

[0090] In step S11, the X-coordinate εx of the midpoint position ε1 in the Y direction of the XY plane image of the front wall 2b is determined and compared with the loading appropriate range ε2 stored in memory 70a. When moving the hook 38c below the round bar 22 to hook it, if the vehicle is too far away from the container 2 (front wall 2b) in the X direction, the hook 38c will not hook onto the round bar 22. Conversely, if the vehicle is too close in the X direction, the loading arm 34 will interfere with the front wall 2b, making it difficult to move the hook 38c below the round bar 22. Therefore, the loading appropriate range ε2 is set in advance based on the dimensions of the loading arm 34, etc., and stored in memory 70a.

[0091] Then, if the X coordinate εx of the midpoint position ε1 in the Y direction of the front wall 2b is greater than the appropriate loading range ε2 (εx>ε2), that is, if the vehicle has not reached the appropriate reversing position, the process returns to step S5. On the other hand, if the X coordinate εx of the midpoint position ε1 in the Y direction of the front wall 2b is less than or equal to the appropriate loading range ε2 (εx≦ε2), that is, if the vehicle has reached the appropriate reversing position, the process proceeds to step S12a. In step S12a, if a reversing alarm is currently sounding, it is deactivated, and the buzzer 74a is used to notify the operator that the vehicle has reached the appropriate reversing position, prompting them to stop at that position. After that, the process proceeds to step S13.

[0092] In step S13, it is determined whether or not a neutral signal based on the driving operation of the container handling vehicle 1 has been input to the control unit 70. If a neutral signal has been input, the process proceeds to step S14. On the other hand, if a neutral signal has not been input, the process waits until this signal is input. Step S13 is a step that determines whether or not the vehicle has come to a stop by utilizing the fact that the gear is shifted to neutral when the vehicle is brought to a stop from a reverse position.

[0093] In step S14, the scanning of the sensor head 8 for safety confirmation and reversing guidance during vehicle reversing is completed. Next, the hook 38c is attached to the round bar 22 to load the container 2. When loading the container 2 automatically, the operator turns on the PTO switch in the cab 12 and turns on the automatic loading button 74f on the remote controller 74.

[0094] In step S15, it is determined whether the ON operation signal for the PTO switch and the ON operation signal for the automatic loading button 74f have been input to the control unit 70. If these ON operation signals have been input, the process proceeds to step S16; if these ON operation signals have not been input, the process waits until these signals are input.

[0095] In step S16, scanning of the sensor head 8 is started in the same manner as in step S4 described above, and then the process proceeds to step S17. In step S17, the electric motor 8b is driven to change the orientation of the sensor head 8 so that laser pulses are irradiated onto the laser irradiation area W2 above the vehicle (see Figure 9(b)). With the sensor head 8 rotated upward in this manner, the process proceeds to step S18.

[0096] Regarding the recognition process of the upper obstacle in step S18, it will be described with reference to FIG. 13. First, step S18a is the same as step S5a in FIG. 11, and step S18b is the same as step S5b in FIG. 11, so the description here is omitted. In step S18c, among the XYZ orthogonal coordinate data (Px, Py, Pz) obtained in step S18b, the X coordinate and the Y coordinate are data within the passing area R1 (see FIG. 28) through which the loading arm 34 and the container 2 pass when the loading arm 34 is rotated back and forth, and the Z coordinate is data below the maximum height of the hook 38c when the loading arm 34 is rotated. This data is extracted as the recognition target data and proceeds to step S18d. When the loading arm 34 is rotated back and forth, since the hook 38c reaches the maximum height when passing near the upper part of the second rotation axis 33 which is the rotation center, the extraction range of the data can be set based on the dimensions of the loading arm 34 and the container 2.

[0097] Next, in step S18d, in the same manner as step S5d in FIG. 11, one set of adjacent measurement points among the recognition target data obtained in step S18c is orthogonally projected onto the XY plane and extracted as the two-dimensional object image C. After extracting the object image C, it proceeds to step S18e.

[0098] In step S18e, the total area C1 of the object image C is compared with the above-mentioned obstacle determination threshold B2 (see step S8e in FIG. 12). If the total area C1 is greater than or equal to the obstacle determination threshold B2 (C1≧B2), it proceeds to step S18f. On the other hand, if the total area C1 is less than the obstacle determination threshold B2 (C1<B2), it proceeds to step S18g. The total area C1 of the object image C can be calculated in the same manner as step S5e in FIG. 11.

[0099] Then, in step S18f, object image C is recognized as an overhead obstacle, and the process proceeds to the next step S18h. On the other hand, in step S18g, object image C is recognized as not an overhead obstacle, and the process proceeds to the next step S18h. In step S18h, it is determined whether the analysis (analysis of whether or not an overhead obstacle) has been completed for all sets (object images C). If the analysis has been completed, the process proceeds to step S18i. On the other hand, if the analysis has not been completed, the process returns to step S18e and is repeated until it is determined that the analysis has been completed.

[0100] If overhead obstacles are recognized based on the recognition result of only one frame, there is a possibility that objects that do not hinder loading, such as debris that is blown by the wind and temporarily enters the passage area R1, may be recognized as obstacles. In order to exclude such temporarily entering objects from being considered overhead obstacles, the following steps S18i, S18j, and S18k are performed.

[0101] In step S18i, it is determined whether or not the recognition process for an overhead obstacle has been performed for the second frame (recognition target data acquired a predetermined time after scanning the first frame). If the process proceeds from step S18h to S18i for the first time, the recognition process for the second frame has not yet been performed, so the process proceeds to step S18k. On the other hand, if the process proceeds to step S18i after the recognition process for the second frame has been performed, the process proceeds to step S18j.

[0102] In step S18k, after waiting for a predetermined time (for example, about 2 seconds), the process returns to step S18a to acquire the recognition target data for the second frame and perform the recognition process for the overhead obstacle. In step S18j, the positions of the object image C recognized as an overhead obstacle in the first frame and the object image C recognized as an overhead obstacle in the second frame are compared. If both are in the same position, this object image C is extracted as a true overhead obstacle (for example, a low ceiling that hinders container loading), and the process proceeds to step S19 in Figure 10. On the other hand, if their positions are different, it is determined that the object image C is not an overhead obstacle, and the process proceeds to step S19 in Figure 10.

[0103] Next, in step S19, based on the determination result of step S18j in Figure 13, if there is no overhead obstacle, the process proceeds to step S20. On the other hand, if there is an overhead obstacle, the process proceeds to step S28, where an overhead obstacle warning is issued by buzzer 74a, and then the process proceeds to step S38, which will be described later.

[0104] In step S20, the electric motor 8b is driven to change the orientation of the sensor head 8 so that laser pulses are irradiated onto the laser irradiation area W1 (see Figure 9(a)) at the rear of the vehicle, and the process proceeds to step S21.

[0105] The recognition process of the front wall 2b and round bar 22 of container 2 in step S21 will be explained with reference to Figure 14. First, step S21a is the same as step S5a in Figure 11, and step S21b is the same as step S5b in Figure 11, so the explanation here will be omitted. In step S21c, from the XYZ Cartesian coordinate data (Px, Py, Pz) obtained in step S21b, data with an X coordinate near the appropriate retraction position is extracted by referring to the loading appropriate range ε2 (see step S11 in Figure 10) and used as the data to be recognized, and the process proceeds to step S21d.

[0106] In step S21d, similar to step S5d in Figure 11, the set of adjacent measurement points from the recognition target data obtained in step S21c is orthogonally projected onto the YZ plane and extracted as a 2D object image D. After extracting the object image D, the process proceeds to step S21e. Of the following steps, the steps related to the recognition process of the front wall 2b of container 2 are the same as in Figure 11 described above. In other words, steps S21e to S21i are the same as steps S5e to S5i in Figure 11, so their explanation is omitted here.

[0107] In step S21j, the object image D obtained in step S18d is compared with the round bar feature data, and data corresponding to the round bar 22 is extracted from the object image D, and the process proceeds to step S21k. The round bar feature data is data created in advance by extracting the shape and size features of the round bar 22, and is stored in the memory 70a of the control unit 70. As the round bar feature data, for example, data of a rod-shaped member that extends in the vehicle width direction and is curved so as to be convex toward the front can be used.

[0108] Then, in step S21k, it is determined whether the analysis (analysis of whether or not it is the front wall 2b) has been completed for all sets (object images D). If the analysis has been completed, the process proceeds to step S22 in Figure 10. On the other hand, if the analysis has not been completed, the process returns to step S21e and is repeated until it is determined that the analysis has been completed.

[0109] In step S22 of Figure 10, XYZ Cartesian coordinate data indicating the position of the round bar 22 is calculated based on the data of the round bar 22 extracted in step S21j of Figure 14.

[0110] Next, in step S23, in order to move the hook 38c of the loading arm 34 to the loading start position where it can engage with the round bar 22 of the container 2 at the position calculated in step S22, the stroke amounts S1 and S2 (extension direction and extension amount) of the lift cylinders 35, 36 and slide cylinder 39 required to move the hook 38c to the loading start position are calculated. The stroke amounts S1 and S2 are calculated as follows. Here, the relationship between the minute extension amount ΔY of the slide cylinder 39 and the minute extension amount ΔX of the lift cylinders 35 and 36 will be explained with reference to Figures 16 and 17.

[0111] Figure 16 is a skeleton diagram showing the load handling arm 34, lift cylinders 35, 36, etc., when they are in a horizontal (downloaded) position. In Figure 16, P1 is the pivot point of the load handling arm 34 (axis of the second pivot axis 33 (see Figure 1)), P2 is the pivot point on the base end side of the lift cylinders 35, 36, and P3 is the connection point between the lift cylinders 35, 36 and the load handling arm 34. In the same figure, a is the height of the engagement center of the hook 38c relative to the pivot center point P1, b+S1 (S1 is the stroke amount of the slide cylinder 39) is the horizontal distance from the pivot center point P1 to the engagement center of the hook 38c, L is the distance from the pivot center point P1 to the engagement center of the hook 38c, θa is the angle between the line segment connecting the pivot center point P1 and the engagement center of the hook 38c and the line segment extending from the pivot center point P1 in the extension / retraction direction of the load handling arm 34, e+S2 (S2 is the stroke amount of the lift cylinder 36) is the length of the line segment connecting the pivot center point P2 and the connection point P3, d is the length of the line segment connecting the pivot center point P1 and the connection point P3, c is the length of the line segment connecting the pivot center point P1 and the pivot center point P2, and θoc is the angle between the line segment connecting the pivot center point P1 and the connection point P3 and the line segment connecting the pivot center point P1 and the pivot center point P2.

[0112] Figure 17 is a skeleton diagram showing the state of the lifting arm 34, etc., when the lift cylinder 36 is at a predetermined stroke amount S2. In Figure 17, WL is a horizontal line passing through the pivot center point P1, θout is the rotation angle of the lifting arm 34 from the grounded state, H is the height of the engagement center of the hook 38c with respect to the horizontal line WL (also called "catching height H"), and θx is the angle that the line segment connecting the pivot center point P1 and the engagement center of the hook 38c makes with respect to the horizontal line WL (also called "catching angle θx").

[0113] In the following, the variables H, L, θa, θout, and θoc immediately before the slide cylinder 39 and lift cylinders 35 and 36 are extended by a small amount ΔY and a small amount ΔX will be denoted as variables H1, L1, θa1, θout1, and θoc1, respectively, and the variables H, L, θa, θout, and θoc after the slide cylinder 39 and lift cylinders 35 and 36 have been extended by a small amount ΔY and a small amount ΔX will be denoted as variables H2, L2, θa2, θout2, and θoc2, respectively.

[0114] When the variables are set as described above, L1, L2, θa1, and θa2 can be expressed as shown in equations 1 to 4 below.

[0115]

number

[0116]

number

[0117]

number

[0118]

number

[0119] Here, the catching height H satisfies the relationship in Equation 5, so using Equations 1 to 4 above, Equations 6 to 9 hold true.

[0120]

number

[0121]

number

[0122]

number

[0123]

number

[0124]

number

[0125] Furthermore, as shown in Figure 17, c, d, e+S2, and θoc satisfy the relationships in Equations 10 and 11 by the Law of Cosines.

[0126]

number

[0127]

number

[0128] Furthermore, the rotation angle θout of the loading arm 34 from its resting position can be expressed as shown in the following equation 12. Here, θoc0 represents the angle between the line segment connecting the rotation center point P1 and the connection point P3 and the line segment connecting the rotation center point P1 and the rotation center point P2 when the loading arm 34 is in its resting position.

[0129]

number

[0130] Substituting equations 10 and 11 above into equation 12 yields equations 13 and 14.

[0131]

number

[0132]

number

[0133] Then, by substituting equation 13 into equation 7, and equation 14 into equation 9, and further substituting the stroke amounts S1 and S2 of the lift cylinders 35, 36 and the slide cylinder 39, a relationship between ΔX and ΔY is obtained. Based on the above relationship, the control unit 70 can calculate the position of the hook 38c of the cargo handling arm 34 by setting the stroke amounts S1 and S2 of the lift cylinders 35, 36 and the slide cylinder 39.

[0134] Next, in step S24, the lift cylinders 35, 36 and slide cylinder 39 are driven by a predetermined amount smaller than the stroke amounts S1 and S2 calculated in step S23, and the loading arm 34 is moved toward the loading start position where the hook 38c can engage with the round bar 22 of the container 2 placed on the ground. The loading start position is set by the forward rotation of the loading arm 34 to a position where the hook 38c can engage with the round bar 22 of the container 2.

[0135] In step S25, the same obstacle recognition process as in step S8 (see steps S8a to S8h in Figure 12) is performed to recognize obstacles between the vehicle and the container 2. If it is determined that there are no obstacles (there are no obstacles of a certain size or larger between the vehicle and the container 2), the process proceeds to step S26. On the other hand, if it is determined that there are obstacles, the process proceeds to step S29. In step S29, the drive of the loading arm 34 is stopped, and a catching alarm is issued from the buzzer 74a to alert the worker. If a catching alarm was issued from the buzzer 74a in step S26, it is deactivated, and the process proceeds to step S27.

[0136] In step S27, it is determined whether the hook 38c of the loading arm 34 has moved to the loading start position where it can engage with the round bar 22 of the container 2. In this case, it is determined whether the lift cylinders 35, 36 and the slide cylinder 39 have been driven by the stroke amounts S1 and S2 calculated in step S23, based on the output values ​​of the stroke sensors 72 and 73. If the hook 38c has moved to the loading start position, the process proceeds to step S30. On the other hand, if the hook 38c has not moved to the loading start position, the process in steps S24 to S26 is repeated until a positive determination is obtained (until the hook 38c moves to the loading start position).

[0137] In step S29, the movement of the loading arm 34 is stopped midway, but if the operator removes the obstacle causing the catching alarm, the process in steps S24 to S26 will automatically resume. Alternatively, instead of automatic resumption, the process in steps S24 to S26 may be resumed when the operator removes the obstacle behind the vehicle and then operates the automatic loading button 74f again.

[0138] In step S30, the lift cylinders 35, 36 and the slide cylinder 39 are driven, and the loading arm 34 is moved a predetermined distance toward the loading completion position (the position shown by the solid line in Figure 1). As the loading arm 34 moves, the hook 38c of the loading arm 34 engages with the round bar 22 of the container 2, and from this state, the loading arm 34 rotates further forward, lifting the container 2 off the ground.

[0139] Then, in step S31, when the loading arm 34 is rotated forward, a recognition process of the front wall 2b of the container 2 is performed to determine whether there are any obstacles between the vehicle and the container 2. The recognition process of the front wall 2b of the container 2 in step S31 will be explained with reference to Figure 15. First, step S31a is the same as step S5a in Figure 11, step S31b is the same as step S5b in Figure 11, and step S31c is the same as step S21c in Figure 14, so the explanation here will be omitted.

[0140] In step S31d, similar to step S5d in Figure 11, the set of adjacent measurement points from the recognition target data obtained in step S31c is orthogonally projected onto the YZ plane and extracted as a 2D object image E. After extracting the object image E, the process proceeds to step S31e.

[0141] Step S31e is the same as step S5e in Figure 11, so its explanation is omitted here. If the total area of ​​object image E is greater than or equal to a predetermined value, and there is a possibility that object image E is the front wall 2b of container 2, the process proceeds to step S31f. On the other hand, if the total area of ​​object image E is less than a predetermined value, the process proceeds to step S31g.

[0142] When the loading arm 34 is rotated forward to lift the container 2, the front wall 2b tilts in accordance with the rotation of the loading arm 34. Therefore, as shown in step S21f of Figure 14, it is difficult to accurately recognize the front wall 2b with only one reference front wall feature data. For this reason, multiple front wall feature data corresponding to the rotation position of the loading arm 34 (stroke amount of the lift cylinders 35 and 36) are stored in the memory 70a.

[0143] In step S31f, the current stroke amount of the lift cylinders 35 and 36 is detected based on the input signal from the lift cylinder stroke sensor 72. In step S31h, the front wall feature data corresponding to the stroke amount detected in step S31f is read out. Then, the degree of agreement between the feature parts of the read-out front wall feature data and the object image E extracted in step S31d is analyzed by comparing them.

[0144] Step S31j is the same as step S5h in Figure 11, step S31g is the same as step S5g in Figure 11, and step S31k is the same as step S5i in Figure 11, so their explanation is omitted here. In step S31l, it is determined whether the analysis (analysis of whether it corresponds to the front wall 2b) has been completed for all sets (object images E). If the analysis has been completed, the process proceeds to step S32 in Figure 10. On the other hand, if the analysis has not been completed, the process returns to step S31e and is repeated until it is determined that the analysis has been completed.

[0145] In step S32 of Figure 10, the same obstacle recognition process as in step S8 (see steps S8a to S8h in Figure 12) is performed to recognize obstacles between the vehicle and the container 2. If it is determined that there are no obstacles (no obstacles exceeding a certain area between the vehicle and the container 2), the process proceeds to step S33. On the other hand, if it is determined that there are obstacles, the process proceeds to step S36. In step S36, the drive of the loading arm 34 is stopped, and a lifting alarm is issued from the buzzer 74a to alert the worker. If a lifting alarm has been issued from the buzzer 74a in step S33, it is deactivated, and the process proceeds to step S34.

[0146] In step S34, it is determined whether the main girder 21 of the bottom wall 2a of container 2 is on the guide roller 16. The main girder 21 of container 2 being on the guide roller 16 means, for example, as shown in Figure 29, that most of the bottom surface of the main girder 21 of container 2 is in contact with the outer surface of the guide roller 16 and is not off-center from the guide roller 16 in the vehicle width direction. This determination is made using image data captured by side cameras 9L and 9R.

[0147] Specifically, image data is acquired from side cameras 9L and 9R, and the acquired input image data is subjected to processes such as binarization and labeling. Binarization is a process in which, for example, if the brightness value of each pixel in the input image data is above a predetermined threshold, it is set to the maximum brightness value, and if it is below the threshold, it is set to the minimum brightness value. The resulting binarized image data has much of the noise and the effects of light intensity changes removed. Labeling is a process in which pixels that are close to each other in the binarized image data are designated as regions. For example, multiple pixels that belong to the same brightness value and are closely located within a predetermined distance are considered as one region. Labeling is performed on the entire image plane, and each of these designated regions is recognized as an object image. Then, for each object image, loading feature data is referenced, and if the conditions of this loading feature data are met, it is determined that the main girder 21 of container 2 is on the guide roller 16, and the process proceeds to step S35. The loading feature data is obtained by taking images of the main girders 21 and guide rollers 16 of many containers 2 in advance (images of the main girders 21 of containers 2 in the state where they are resting on the guide rollers 16), and extracting features such as size and shape, which are stored in memory 70a. On the other hand, if the conditions of the loading feature data are not met for each object image, and it is determined that the main girders 21 of container 2 are not resting on the guide rollers 16, the process is returned to step S30 and the process from steps S30 to S34 is repeated until a positive determination is obtained (until it is determined that the main girders 21 of container 2 are resting on the guide rollers 16).

[0148] In step S36, the drive of the lift cylinders 35, 36 and the slide cylinder 39 is stopped, the movement of the load handling arm 34 is stopped, and an alarm sound is emitted by the buzzer 74a to notify the worker. In this case, the movement of the load handling arm 34 is stopped midway, but if the worker removes the obstacle causing the lifting alarm, the process in steps S30 to S34 will be automatically resumed. Alternatively, instead of automatic resumption control, the process in steps S30 to S34 may be resumed when the worker removes the obstacle behind the vehicle and then operates the automatic loading button 74f again.

[0149] In step S35, for example, a proximity sensor (not shown) is used to determine whether the lift cylinders 35, 36 and the slide cylinder 39 have extended or retracted to the loading completion position, that is, whether the loading arm 34 has moved to the loading completion position. If the loading arm 34 has moved to the loading completion position, the process proceeds to step S37. On the other hand, if the loading arm 34 has not moved to the loading completion position, the process in steps S30 to S35 is repeated until a positive determination is obtained.

[0150] In step S37, the buzzer 74a emits an audio signal indicating that loading is complete, notifying the worker that the loading operation of container 2 is complete, and the process proceeds to step S38. In step S38, it is determined whether the PTO switch has been turned off, and if the off operation is confirmed, the process proceeds to step S39. In step S39, if an upward obstruction alarm (step S28) has been triggered, it is cleared, and the process proceeds to step S40. In step S40, the scanning of the sensor head 8 for automatic loading, which was started in step S16, is terminated, and the automatic loading control flow performed by operating the automatic loading button 74f is terminated.

[0151] Next, with reference to Figure 18, the control during automatic unloading in the container handling vehicle 1 will be explained.

[0152] First, in step S41, the system remains in a standby state until the ACC power is turned on, or in other words, until power corresponding to the ACC power being turned on is input to the control unit 70. Then, once power is input, the system proceeds to step S42. In step S42, after performing an initialization process, the control unit 70 rotates the sensor head 8 backward (to the direction in which laser pulses are irradiated onto the laser irradiation area W1) and proceeds to step S43.

[0153] In step S43, the control unit 70 determines whether an ON operation signal for the PTO switch and an ON operation signal for the automatic lowering button 74g have been input to the control unit 70. If these ON operation signals have been input, the process proceeds to step S43a; if these ON operation signals have not been input, the process waits until these signals are input.

[0154] In step S43a, the side cameras 9L and 9R are turned on to capture images of the area behind the vehicle. The image data captured by the side cameras 9L and 9R is set as the background reference image data and saved to memory 70a.

[0155] Then, in step S44, while the loading arm 34 is lowering the container 2, the system recognizes obstacles within the planned container lowering area R2. The planned container lowering area R2 is a predefined area where the container 2 may be lowered, as shown in Figure 28, and is stored in memory 70a. The planned container lowering area R2 can be set, for example, based on the front-to-back dimensions of the loading arm 34 when it is rotated near the rear limit position, and the planar dimensions of the container 2.

[0156] The process of recognizing obstacles within the container unloading area R2 in step S44 will be explained with reference to Figure 19. First, since step S44a is the same as step S5a in Figure 11 and step S44b is the same as step S5b in Figure 11, their explanations will be omitted here. In step S44c, from the XYZ Cartesian coordinate data (Px, Py, Pz) obtained in step S44b, the data where the X and Y coordinates are within the container unloading area R2 are extracted and used as the first data to be recognized, and the process proceeds to step S44d.

[0157] In step S44d, the current stroke amount of the lift cylinders 35 and 36 is detected based on the input signal from the lift cylinder stroke sensor 72. In step S44e, the recognition restriction Z coordinate corresponding to the stroke amount detected in step S44d is read out. When the loading arm 34 is rotated to the rear to lower the container 2, as shown in Figures 30 to 32, the field of view of the rear of the vehicle as seen from the sensor head 8 is gradually narrowed as the container 2 obstructs the view as the loading arm 34 rotates. Therefore, in order to exclude the data corresponding to the container 2 from the first recognition target data extracted in step S44c, a recognition restriction Z coordinate corresponding to the current stroke amount of the lift cylinders 35 and 36 is set. Multiple recognition restriction Z coordinates corresponding to the rotation position of the loading arm 34 (stroke amount of the lift cylinders 35 and 36) are stored in the memory 70a. For example, as shown by the dashed line in Figures 30 and 31, the recognition restriction Z coordinate can be set to a position slightly lower than the lower end of the container 2 (here, the pair of left and right wheels 2e, 2e).

[0158] Then, in step S44f, from the first recognition target data extracted in step S44c, data whose Z coordinate is less than or equal to the recognition restriction Z coordinate read in step S44e is extracted and designated as the second recognition target data, and the process proceeds to step S44g.

[0159] In step S44g, in the same manner as step S5d in FIG. 11, among the second recognition target data obtained in step S44f, a set of adjacent measurement points is orthogonally projected onto the YZ plane and extracted as a two-dimensional object image F. After extracting the object image F, the process proceeds to step S44h.

[0160] In step S44h, the total area F1 of the object image F is compared with the above-described obstacle determination threshold B2 (see step S8e in FIG. 12). If the total area F1 of the object image F is greater than or equal to the obstacle determination threshold B2 (F1 ≥ B2), the process proceeds to step S44i. On the other hand, if the total area F1 is less than the obstacle determination threshold B2 (F1 < B2), the process proceeds to step S44j. The total area F1 of the object image F can be calculated in the same manner as step S5e in FIG. 11.

[0161] Then, in step S44i, if it is recognized that there is an obstacle in the container unloading planned area R2, the process proceeds to the next step S44k. On the other hand, in step S44j, if it is recognized that there is no obstacle in the container unloading planned area R2, the process proceeds to the next step S44k. In step S44k, it is determined whether analysis (analysis of whether there is an obstacle in the container unloading planned area R2) has been completed for all sets (object images F). If the analysis has been completed, the process proceeds to step S45 in FIG. 18. On the other hand, if the analysis has not been completed, the process returns to step S44h and is repeated until it is determined that the analysis has been completed.

[0162] In step S45 of FIG. 18, based on the recognition process of step S44, if there is no obstacle in the container unloading planned area R2, the process proceeds to step S46. On the other hand, if there is an obstacle in the container unloading planned area R2, the process proceeds to step S49.

[0163] In step S46, during the operation of lowering the container 2 by the cargo handling arm 34, in order to determine the presence or absence of an obstacle approaching the container 2 (container lowering planned area R2), the obstacle recognition process by the side cameras 9L and 9R is performed. As described above, when the cargo handling arm 34 is rotated backward to lower the container 2, the view of the rear of the vehicle seen from the sensor head 8 gradually becomes narrower due to being blocked by the container 2 as the cargo handling arm 34 rotates. Therefore, using the image data captured by the side cameras 9L and 9R, the presence or absence of an obstacle approaching the container 2 is determined during the operation of lowering the container 2 by the cargo handling arm 34.

[0164] The obstacle recognition process by the side cameras 9L and 9R in step S46 will be described with reference to FIG. 20. First, in step S46a, the control unit 70 acquires the image data captured by the side cameras 9L and 9R. Next, in step S46b, the control unit 70 reads out the background reference image data acquired in step S43a of FIG. 18, compares the image data captured by the side cameras 9L and 9R with the background reference image data, and performs a difference process between the two. By this difference process, the image data of members different from the background reference image data among the image data captured by the side cameras 9L and 9R is extracted. In steps S46c to S46e, for the image data extracted by the difference process in step S46b, in the same manner as step S34 of FIG. 10, binarization processing and labeling processing are performed, and what is made into one region by the labeling processing is extracted as the object image G.

[0165] In step S46f, the total area G1 of the object image G is compared with the above-described obstacle determination threshold B2 (see step S8e of FIG. 12). If the total area G1 of the object image G is greater than or equal to the obstacle determination threshold B2 (G1 ≥ B2), the process proceeds to step S46g. On the other hand, if the total area F1 is less than the obstacle determination threshold B2 (G1 < B2), the process proceeds to step S44h. The total area G1 of the object image G can be calculated based on the number of pixels of the object image G.

[0166] In step S46g, it is determined whether the object image G is contained within the hazardous area R3. The hazardous area R3 is a roughly rectangular region set to the side of the container 2 in the rear view of the vehicle, as shown in Figure 29, for example. Figure 29 only shows the hazardous area R3 set to the left of the container 2, but a similar hazardous area R3 is also set to the right of the container 2. If even a part of the object image G is contained within the hazardous area R3, the process proceeds to step S46i; otherwise, the process proceeds to step S46h.

[0167] Then, in step S46i, if an obstacle is detected approaching container 2 (the planned container unloading area R2), the process proceeds to the next step S46j. On the other hand, in step S46h, if it is detected that there is no obstacle approaching container 2 (the planned container unloading area R2), the process proceeds to the next step S46j. In step S46j, it is determined whether the analysis (analysis of obstacles approaching container 2) has been completed for all sets (object images G). If the analysis has been completed, the process proceeds to step S47 in Figure 18. On the other hand, if the analysis has not been completed, the process returns to step S46f and is repeated until it is determined that the analysis has been completed.

[0168] In step S47 of Figure 18, if, based on the recognition process in step S46, there are no obstacles approaching container 2 (the planned container unloading area R2), the process proceeds to step S48. On the other hand, if there are obstacles approaching container 2 (the planned container unloading area R2), the process proceeds to step S49.

[0169] In step S48, the lift cylinders 35, 36 and the slide cylinder 39 are driven, and the loading arm 34 (hook 38c) is moved a predetermined distance toward the unloading completion position. In step S50, for example, a proximity sensor (not shown) is used to determine whether the lift cylinders 35, 36 and the slide cylinder 39 have extended or retracted to the unloading completion position, that is, whether the loading arm 34 has moved to the unloading completion position. If the loading arm 34 has moved to the unloading completion position, the process proceeds to step S51. On the other hand, if the loading arm 34 has not moved to the loading completion position, the process from steps S44 to S48 is repeated until a positive determination is obtained.

[0170] In step S49, the drive of the lift cylinders 35, 36 and the slide cylinder 39 is stopped, the movement of the load handling arm 34 is stopped, and an alarm sound is emitted by the buzzer 74a to notify the worker. In this case, the movement of the load handling arm 34 is stopped midway, but if the worker removes the obstacle causing the alarm, the process in steps S44 to S50 is automatically resumed, and the movement of the load handling arm 34 resumes. Alternatively, instead of automatic resumption control, the process in steps S44 to S50 may be resumed by the worker removing the obstacle and then operating the automatic lowering button 74g again.

[0171] In step S51, the buzzer 74a emits an audio signal indicating that the unloading of container 2 is complete, notifying the operator that the unloading operation of container 2 is finished, and the process proceeds to step S52. In step S52, it is determined whether or not the PTO switch has been turned off, and if the off operation is confirmed, the process proceeds to step S53. In step S53, the scanning of the sensor head 8 for automatic unloading is terminated, and the side cameras 9L and 9R are turned off, ending the automatic unloading control flow.

[0172] According to this embodiment, the control unit 70 of the cargo handling device 3 can recognize the three-dimensional shape of an object (including the container 2 and obstacles) located behind the vehicle and the distance from the vehicle to that object by irradiating laser light from the sensor head 8 and using the reflected light reflected from the object. As a result, the control unit 70 can recognize obstacles located between the vehicle and the container 2, allowing the cargo handling device 3 to autonomously perform the safety check behind the vehicle that was conventionally done by the operator. Furthermore, it eliminates the need for the operator to continuously operate buttons while checking for safety, which was previously a cumbersome task for the operator. Consequently, the burden on the operator in checking for safety behind the vehicle and operating the cargo handling device 3 during the loading and unloading of the container 2 can be reduced.

[0173] Furthermore, in this embodiment, the control unit 70 determines, based on the acquired position information of measurement point P, whether or not an obstacle of a certain area or larger is detected between the vehicle and the container 2 behind it, as seen from the rear of the vehicle, when the vehicle is reversing or during loading operations. As a result, when the vehicle is reversing, if an obstacle of a certain area or larger is detected between the vehicle and the container 2, as seen from the rear of the vehicle, the control unit 70 can issue a signal to temporarily stop the vehicle's reversal. For example, if a worker is driving the vehicle, the control unit 70 will notify the worker with an alarm. If the vehicle is an autonomous vehicle, the control unit 70 will autonomously stop the vehicle's reversal. In this case, since the control unit 70's detection of obstacles is limited to areas of a certain area or larger, the control unit 70 can avoid reacting to small obstacles that do not pose a substantial obstacle. As a result, collisions between the vehicle and substantial obstacles can be avoided, and safety during vehicle reversal can be enhanced.

[0174] Furthermore, during the loading of container 2, if an obstacle exceeding a certain area is detected between the vehicle and container 2 from the rear view of the vehicle, the control unit 70 can issue a signal to temporarily stop the operation of the cargo handling device 3. For example, if a worker is operating the cargo handling device 3, the control unit 70 will notify the worker with an alarm. Also, when the loading operation of the cargo handling device 3 is performed automatically, the control unit 70 will autonomously stop the operation of the cargo handling device 3. In this case, the detection of obstacles by the control unit 70 is limited to areas exceeding a certain area, so the control unit 70 will not react to small obstacles that do not pose a substantial obstacle. As a result, collisions between the cargo handling device 3 and substantial obstacles can be avoided, and the safety of the loading operation of container 2 can be enhanced.

[0175] Furthermore, in this embodiment, when the vehicle is reversing, the control unit 70 determines, based on the acquired position information of measurement point P, whether the lateral tilt of the vehicle relative to the front wall 2b of the container 2 is greater than or equal to a predetermined value, and whether the lateral positional deviation of the vehicle relative to the center of the front wall 2b of the container 2 is greater than or equal to a predetermined value. Also, when the vehicle is reversing, the control unit 70 detects the distance to the front wall 2b of the container 2 based on the acquired position information of measurement point P, and determines whether the vehicle has reversing to a position suitable for loading the container 2 onto the loading / unloading device 3. In this way, by guiding the vehicle's reversal using reflected light from an object after irradiating it with measurement light, the vehicle can be easily moved to a position suitable for loading the container 2 onto the loading / unloading device 3.

[0176] Furthermore, in this embodiment, the control unit 70 calculates the position of the round bar 22 of the container 2 based on the acquired position information of the measurement point P, and controls the amount of operation of the drive actuator (stroke amounts S1, S2 of the lift cylinders 35, 36 and slide cylinder 39) based on the calculated position of the round bar 22 to perform a loading operation in which the hook 38c of the loading arm 34 engages with the round bar 22 of the container 2. As a result, even if the vehicle's stopping position is slightly off from the position suitable for loading the container 2, the control unit 70 can autonomously operate the loading arm 34 to reliably engage the hook 38c of the loading arm 34 with the round bar 22 of the container 2. Conventionally, such operation of the loading arm 34 involved reversing the vehicle while positioning the hook 38c of the loading arm 34 in front of the round bar 22 of the container 2, which was not easy even for a skilled driver. However, according to this embodiment, even if a novice is performing the loading operation of the container 2 alone, the hook 38c of the loading arm 34 can be easily and reliably engaged with the round bar 22 of the container 2. Furthermore, since the loading arm 34 can be operated autonomously, the loading and unloading operation can be made more efficient by applying the loading and unloading device 3 of the present invention to an autonomously driven vehicle chassis.

[0177] Furthermore, in this embodiment, the sensor head 8 is provided so that it can also emit measurement light upwards on the vehicle. The control unit 70 detects obstacles above the vehicle based on the acquired position information of the measurement point P and determines whether the height of the detected obstacle is higher than the maximum height of the hook 38c of the loading arm 34 when performing the loading operation. This makes it easy to check whether there are any obstacles above the vehicle that may interfere with the loading arm 34 when performing the loading operation.

[0178] Furthermore, in this embodiment, the control unit 70 determines whether the container 2 is placed on the predetermined position (guide roller 16) on the vehicle chassis based on images captured by the side cameras 9L and 9R during the loading operation. This ensures that the container 2 is reliably placed on the predetermined position on the vehicle chassis during the loading operation, thereby improving the efficiency of the loading work.

[0179] Furthermore, in this embodiment, during unloading operations, the control unit 70 determines, based on the acquired position information of measurement point P, whether or not an obstacle of a certain size or larger has been detected in the planned container unloading area R2 at the rear of the vehicle, as seen from the rear of the vehicle. As a result, when unloading container 2, if an obstacle of a certain size or larger is detected in the planned container unloading area R2 at the rear of the vehicle, as seen from the rear of the vehicle, the control unit 70 can issue a signal to temporarily stop the operation of the cargo handling device 3. For example, if an operator is operating the cargo handling device 3, the control unit 70 will notify the operator with an alarm. Also, when the unloading operation of the cargo handling device 3 is performed automatically, the control unit 70 autonomously stops the operation of the cargo handling device 3. In this case, since the detection of obstacles by the control unit 70 is limited to areas of a certain size or larger, the control unit 70 can avoid reacting to small obstacles that do not pose a substantial obstacle. As a result, collisions between the cargo handling device 3 and substantial obstacles can be avoided, and the safety of the container unloading operation can be enhanced.

[0180] Furthermore, in this embodiment, when the cargo handling device 3 performs the unloading operation of the container 2 mounted on the vehicle chassis, the control unit 70 determines whether or not there is an object approaching the planned container unloading area R2 based on the acquired position information of measurement point P and the images captured by the side cameras 9L and 9R. As a result, if an object approaches the container 2 during the unloading operation of the container 2 by the cargo handling arm 34, the unloading operation of the container 2 can be stopped immediately, thereby ensuring safety during the unloading operation of the container 2.

[0181] -Other Embodiments- The embodiments disclosed herein are illustrative in all respects and are not intended to be restrictive. The technical scope of the present invention is not construed solely by the embodiments described above, but is defined by the claims. Furthermore, the technical scope of the present invention includes all modifications within the meaning and scope of equivalence to the claims.

[0182] In the above embodiment, the sensor head 8 is configured in which a laser light source (irradiation unit) 81 and a light receiver (light receiving unit) 86 are provided integrally. However, it is not limited to this configuration, and the laser light source 81 and the light receiver 86 may be installed in separate locations as long as it is possible to irradiate laser light toward the rear of the vehicle. In addition, in the above embodiment, the sensor head 8 is described as a sensor for acquiring three-dimensional position information of an object, equipped with a laser light source 81, a polygon mirror 83, an oscillating mirror 84, a main scanning motor 87, a sub-scanning motor 88, etc., and irradiating laser pulses onto the laser irradiation areas W1 and W2. However, it is not limited to this configuration, and for example, a distance image sensor may be used to acquire three-dimensional position information of an object. Furthermore, in the above embodiment, laser light was used as the measurement light irradiated by the sensor head 8, but it is not limited to this configuration, and LED light may be used as the measurement light.

[0183] Furthermore, a stereo camera may be used as an object image acquisition unit to acquire object image data of objects around the vehicle and the distance to said object image. In other words, while the sensor head 8 described above calculates the 3D position information of objects around the vehicle based on measurement light that is irradiated onto the objects around the vehicle and reflected by the objects, the 3D position information of objects around the vehicle may also be calculated based on images taken of the objects around the vehicle by a stereo camera. A stereo camera can calculate the position information of the camera pixels by simultaneously photographing objects around the vehicle from multiple different directions using two cameras (two-lens cameras), thereby enabling the recognition of the 3D shape of objects around the vehicle (including cargo handling objects and obstacles) and the distance from the vehicle to those objects.

[0184] Therefore, even when a stereo camera is used as the object image acquisition unit, the control unit can recognize the presence of obstacles between the vehicle and the cargo being handled, just as when the sensor head 8 described above is used. This allows the vehicle to autonomously perform safety checks, such as checking the rear, which were previously done by the operator. Furthermore, it eliminates the need for the operator to continuously operate buttons while checking for safety, which was previously a cumbersome task. As a result, the burden on the operator in checking for safety behind the vehicle and operating the vehicle can be reduced. Note that the sensor head 8 described above and an imaging camera (such as a monocular camera or stereo camera) may be used in combination as the object image acquisition unit to acquire data on the object images of objects around the vehicle and the distance to those object images.

[0185] Furthermore, in the above embodiment, the sensor head 8 is provided at one location on the rear end of the vehicle, and the side cameras 9L and 9R are provided at two locations on the side of the vehicle. However, the system is not limited to this, and the sensor head 8 may be provided at two locations on the side of the vehicle instead of the side cameras 9L and 9R. Alternatively, the sensor head may be provided at one location on the side of the vehicle, and the rear camera may be provided at one location on the rear end of the vehicle.

[0186] In the above embodiment, 3D polar coordinate data (L,θ,φ) was converted to XYZ Cartesian coordinate data (Px,Py,Pz), and recognition processing for container 2, etc., was performed based on this XYZ Cartesian coordinate data. However, recognition processing for container 2, etc., may also be performed directly based on the 3D polar coordinate data without performing coordinate conversion.

[0187] In the above embodiment, an example of applying the present invention to a container handling vehicle 1 configured to slide the hook 38c (hook frame 38) in the front-rear direction using a slide cylinder 39 was described. However, the present invention is not limited to this and can also be applied to container handling vehicles configured to swing (oscillate) the hook 38c in the front-rear direction using a cylinder. Furthermore, the present invention can also be applied to handling vehicles configured to load and unload containers while keeping them horizontal, such as the one disclosed in Japanese Patent Publication No. 63-036973.

[0188] The above describes the application of the present invention to container handling vehicles, but the scope of application of the present invention is not particularly limited as long as it is a work vehicle equipped with a bodywork on a chassis, and is capable of loading and unloading cargo onto the chassis using the bodywork, or a work vehicle capable of loading transported cargo onto the chassis using the bodywork. In short, the work vehicle of the present invention is not particularly limited as long as it is a work vehicle capable of loading and / or unloading cargo onto the chassis using the bodywork. For example, the present invention can also be applied to vehicle carriers such as those disclosed in Japanese Patent Application Publication No. 2016-5928. An appropriate rearward position can be set based on the front-to-rear dimensions of the cargo bed on which the transported vehicle is loaded, and by setting it in this way, it becomes easier to reverse the vehicle toward the transported vehicle in sites where it is difficult to secure loading and unloading space in the front-to-rear direction.

[0189] Furthermore, the present invention can also be applied to vehicle carriers of the type disclosed in, for example, Japanese Patent Publication No. 2000-108769, in which the loading platform for transporting vehicles is detachably configured, and a loading / unloading arm is engaged with the loading platform to load and unload vehicles. In the case of such vehicles, it becomes possible to automatically move the loading / unloading arm by recognizing the engaged portion on the loading platform, and to detect obstacles (safety check) when loading and unloading vehicles from the loading platform.

[0190] Furthermore, the present invention can also be applied to mixer trucks that transport ready-mix concrete to construction sites while stirring it, such as those disclosed in Japanese Patent Publication No. 2010-149638. Generally, mixer trucks are used in a manner in which, after arriving at the construction site, they are moved backward toward the concrete pump truck, and the chute is turned backward to supply the ready-mix concrete to the concrete pump truck. Therefore, by setting the appropriate backward position based on the dimensions of the chute, the operation of moving the truck backward toward the concrete pump truck becomes easier.

[0191] On the other hand, the present invention can also be applied to loading platform lifting devices such as those disclosed in Japanese Patent Publication No. 2006-240380. By positioning the sensor head above the loading platform, on the arm portion of the loading platform, or on the loading platform itself, data corresponding to objects on the loading platform can be extracted, and the presence or absence of object images extending beyond the outside of the loading platform in a plan view can be determined, thereby preventing objects from being caught between the chassis and the loading platform when the loading platform is raised. In particular, if the determination can be made before the loading platform is raised, it is preferable because it can prevent multiple loads stacked on the trolley from collapsing, compared to stopping the process midway through the rise. Furthermore, by attaching the sensor head to the arm portion of the loading platform so that obstacles in the area below the loading platform (objects that would obstruct descent) can be recognized, safety during loading platform descent can be enhanced by stopping the descent based on the determination of the presence of obstacles. Furthermore, it can also be applied to a loading platform lifting device of the type in which a loading platform moves up and down along a vertically installed post, such as the one disclosed in Japanese Patent Publication No. 2007-203906. In this case, by attaching the sensor head to the post, it is possible to prevent objects from getting caught.

[0192] Here, when applying the present invention to a loading platform lifting device as part of a vehicle body, the following form may be used. In this case, the object image acquisition unit acquires data on the object image of a part of the vehicle body whose shape is changing and the distance to the object image, so that the control unit recognizes the three-dimensional shape of the part and the distance from the vehicle to that part. The control unit then recognizes the change in shape of the vehicle body and operates the drive actuator. This modified example will be explained with reference to Figures 33 to 36. Figure 33 is a rear perspective view showing the schematic configuration of a vehicle equipped with a loading platform lifting device 200. Figure 34 is a side view showing the operating state of the loading platform lifting device 200. Figure 35 is a circuit diagram of the control device and hydraulic device provided in the loading platform lifting device 200. Figure 36 is a flowchart showing an example of the operation of the loading platform lifting device 200.

[0193] As shown in Figures 33 and 34, the loading platform lifting device 200 is attached to the rear of the chassis frame, which consists of the vehicle's main frame, via a support member 201. It comprises a loading platform 202, a pair of left and right tilt links 203, a lift arm 204, a tilt cylinder 205, a lift cylinder 206, and a sensor 208 for detecting the rotation angle of the loading platform. When the loading platform 202 is not in use, it is in an upright position facing the rear of the cargo box 209, which is part of the bodywork mounted on the chassis frame. Below the cargo box 209, there is a bumper 210 divided into three sections (210C, 210L, 210R).

[0194] The support member 201 includes a frame member 211 extending in the vehicle width direction below the rear end of the chassis frame, a pair of left and right fixing brackets 212 that secure the frame member 211 to the rear end of the chassis frame, and support brackets 213 provided at both left and right ends of the frame member 211. The tilt link 203 is formed in a substantially U-shape in cross-section that opens to the rear of the vehicle and extends vertically. Its upper part is rotatably connected to the upper part of the support bracket 213 via a pin 231, and its lower part is formed to swing in the front-rear direction of the vehicle. The base end of the lift arm 204 is rotatably connected to the upper part of the tilt link 203 via a pin 241. The tip of the lift arm 204 is rotatably connected to the upper end of the load receiving platform 202 via a pin 242.

[0195] The tilt cylinder 205 is a drive actuator for the loading platform lifting device 200 and functions as a hydraulic cylinder for rotating the loading platform 202, and is located below the lift arm 204. The base end of the tilt cylinder 205 is rotatably connected via a pin 251 between a support bracket 213 and a bracket 214 that faces the support bracket 213 from the outside. The tip of the tilt cylinder 205 is rotatably connected via a pin 252 to the lower end of the loading platform 202.

[0196] The lift cylinder 206 is a drive actuator for the loading platform lifting device 200 and functions as a hydraulic cylinder for raising and lowering the loading platform 202, and is located below the tilt cylinder 205. The base end of the lift cylinder 206 is rotatably connected to the lower part of the tilt link 203 via a pin 261. The tip of the lift cylinder 206 is rotatably connected to the middle part of the lift arm 204 via a pin 262.

[0197] A known proximity sensor is used for the sensor 208 that detects the rotation angle of the loading platform 202. It consists of a detection piece 281 provided on a pin 242 used to connect the tip of the lift arm 204 and the loading platform 202, and a detection unit 282 provided on the loading platform 202 that detects the detection piece 281. The detection piece 281 is rotatably mounted on the pin 242, which is the rotation center of the loading platform 202, and is connected to the loading platform 202 by a connecting member (not shown) so as to rotate in conjunction with the rotational movement of the loading platform 202.

[0198] In the loading platform lifting device 200 having this configuration, the loading platform 202 is in an upright position when the vehicle is in motion, as shown in Figures 33 and 34(a). In this upright position, the tilt cylinder 205 and the lift cylinder 206 are extended.

[0199] On the other hand, in order to load and unload cargo after the vehicle has stopped, the upright loading platform 202 is lowered to a nearly horizontal position at approximately the same height as the loading platform floor 207, as shown by the solid line in Figure 34(b). At this time, the lift cylinder 206 remains extended, but the tilt cylinder 205 is retracted, and the loading platform 202 is rotated by the retraction of the tilt cylinder 205.

[0200] Furthermore, when loading and unloading cargo between the ground and the cargo bed floor 207, the horizontal loading platform 202 is lowered until it touches the ground, as shown by the dashed line in Figure 34(b). At this time, the tilt cylinder 205 remains retracted, and the lift cylinder 206 is also retracted. By retracting the tilt cylinder 205 in this state, the loading platform 202 can be tilted until its front end touches the ground. The operating devices (not shown) for extending and retracting the tilt cylinder 205 and the lift cylinder 206 are located on the side of the rear of the vehicle, allowing the operator to visually confirm the operation status of the loading platform 202.

[0201] Furthermore, as shown in Figure 33, a sensor head 220 is provided on the upper part of the rear surface of the cargo box 209. The sensor head 220 has substantially the same configuration as the sensor head 8 in the above embodiment. The sensor head 220 is configured to irradiate a laser beam as measurement light toward a predetermined area behind the cargo box 209 and to receive the laser beam (reflected light) reflected by an object (see Figure 5, etc.). By scanning the area behind the cargo box 209 with the laser pulse emitted from the sensor head 220, the vertical angle α and horizontal angle β of the laser pulse when the laser pulse is irradiated onto the measurement point P on the object are obtained as 3D polar coordinate data (distance D, vertical angle α, horizontal angle β), which is the position information of the measurement point P.

[0202] As shown in Figure 35(a), the sensor head 220 is connected to the control unit 230, and the 3D polar coordinate data (distance D, vertical angle α, horizontal angle β), which is the position information of the measurement point P acquired by the sensor head 220, is input to the control unit 230. In addition, the sensor 208 described above is connected to the control unit 230, and the detection signal (ON signal) from the sensor 208 is input to the control unit 230. The control unit 230 also has substantially the same functions as the laser control unit 8a in the above embodiment.

[0203] Furthermore, side cameras 221L and 221R are connected to the control unit 230. The side cameras 221L and 221R are substantially the same as the side cameras 9L and 9R in the above embodiment, but the optical axis of the imaging lens of the side cameras 221L and 221R is oriented rearward along the horizontal direction. One side camera 221L is mounted to photograph a predetermined range to the left rear of the vehicle, and the other side camera 221R is mounted to photograph a predetermined range to the right rear of the vehicle. The control unit 230 also has substantially the same functions as the image processing unit 9a in the above embodiment.

[0204] The control unit 230 is connected to an opening / closing switch 232 provided on the operating means 230a for changing the orientation of the loading platform 202 from an upright state to a horizontal state (opening operation) or from a horizontal state to an upright state (closing operation), an upward switch 233 for raising the loading platform 202 in a horizontal state, and a downward switch 234 for lowering the loading platform 202 in a horizontal state. The control unit 230 is also connected to an opening solenoid 238 that is energized by the ON operation of the opening / closing switch 232 and the downward switch 234 to retract the tilt cylinder 205, a closing solenoid 237 that is energized by the ON operation of the opening / closing switch 232 and the upward switch 233 to extend the tilt cylinder 205, and a downward solenoid 236 that is energized by the ON operation of only the downward switch 234 to retract the lift cylinder 206. Furthermore, a buzzer 239 is connected to the control unit 230.

[0205] Furthermore, the control unit 230 is connected to a relay CT1 that closes when the on / off switch 232 is turned on, and the opening and closing of the connection circuit to the motor M1, which is connected to the battery, is controlled by the relay CT1. The motor M1 drives a hydraulic pump P1 that supplies and discharges the hydraulic fluid that causes the tilt cylinder 205 and lift cylinder 206 to contract.

[0206] Each of the solenoids 236 to 238 described above is arranged as shown in Figure 35(b) within a power unit 240 located at a predetermined position on the side of the vehicle. The power unit 240 has a configuration in which a motor M1 and a hydraulic pump P1 are connected to a tilt cylinder 205 or a lift cylinder 206 via a hydraulic fluid supply passage or the like.

[0207] As shown in Figure 35(b), the hydraulic pump P1 has its suction side connected to the oil tank T1 and its discharge side connected to the bottom side of each lift cylinder 206 via a first supply passage 243a. One end of the second supply passage 243b, equipped with a closing solenoid 237, is connected to the first supply passage 243a, and the other end is connected to the bottom side of the tilt cylinder 205. In the first supply passage 243a, a first discharge passage 244a equipped with a lowering solenoid 236 is connected to the lift cylinder 206 side of the connection point with the second supply passage 243b. Also, in the second supply passage 243b, a second discharge passage 244b equipped with an opening solenoid 238 is connected to the tilt cylinder 205 side of the closing solenoid 237. Both the first and second discharge passages 244a and 244b are connected to the oil tank T1. Furthermore, in the first discharge passage 244a, a throttle valve 245 is positioned downstream of the lower solenoid 236 to limit the maximum flow rate of the hydraulic fluid flowing through the first discharge passage 244a, and a relief valve 246 is provided to define the maximum discharge pressure of the hydraulic pump P1.

[0208] In this modified example, obstacle detection processing is performed during the closing operation of the loading platform 202 by the extension movement of the tilt cylinder 205. If there is an obstacle in the area to be closed by the loading platform 202, or if there is an obstacle approaching the area to be closed by the loading platform 202, the closing operation of the loading platform 202 is stopped. On the other hand, if there is no obstacle in the area to be closed by the loading platform 202, and no obstacles approaching the area to be closed by the loading platform 202, the closing operation of the loading platform 202 is performed. This point will be explained with reference to the flowchart in Figure 36.

[0209] First, in step T11, the system remains in a standby state until the ACC power is turned on, or in other words, until power corresponding to the ACC power being turned on is input to the control unit 230. Then, once power is input, the system proceeds to step T12. In step T12, the control unit 230 performs initialization processing and proceeds to step T13.

[0210] In step T13, the control unit 230 determines whether an ON operation signal for the power unit 240 and an ON operation signal for the on / off switch 232 have been input to the control unit 230. If these ON operation signals have been input, the process proceeds to step T14; if these ON operation signals have not been input, the process waits until these signals are input.

[0211] In step T14, the side cameras 221L and 221R are turned on to capture images of the area behind the vehicle. The image data captured by the side cameras 221L and 221R is set as background reference image data and stored in the memory of the control unit 230.

[0212] Then, in step T15, while the loading platform 202 is closing, the sensor head 220 performs a scan and recognizes obstacles within the area to be closed. The area to be closed of the loading platform 202 is a predetermined area that the loading platform 202 passes through when it opens and closes between a horizontal and an upright position, and is stored in memory. This recognition process is substantially the same as the obstacle recognition process in the container unloading area R2 of the above embodiment (step S44 in Figure 18), and its explanation is omitted here.

[0213] In step T16, based on the recognition process in step T15, it is determined whether or not there is an obstacle in the area of ​​the loading platform 202 that is to be closed. If there is no obstacle in the area of ​​the loading platform 202 that is to be closed, the process proceeds to step T17. On the other hand, if there is an obstacle in the area of ​​the loading platform 202 that is to be closed, the process proceeds to step T20.

[0214] In step T17, during the closing operation of the loading platform 202, obstacle recognition processing is performed by the side cameras 221L and 221R to determine whether there are any obstacles approaching the loading platform 202 (the area of ​​the loading platform 202 that is to be closed). In other words, the presence or absence of obstacles approaching the loading platform 202 during the closing operation of the loading platform 202 is determined using image data captured by the side cameras 221L and 221R. This obstacle recognition processing by the side cameras 221L and 221R is substantially the same as the obstacle recognition processing by the side cameras 9L and 9R in the above embodiment (step S46 in Figure 18), and therefore the explanation is omitted here.

[0215] In step T18, if, based on the recognition process in step T17, there are no obstacles approaching the loading platform 202 (the area of ​​the loading platform 202 that is scheduled to be closed), the process proceeds to step T19. On the other hand, if there are obstacles approaching the loading platform 202 (the area of ​​the loading platform 202 that is scheduled to be closed), the process proceeds to step T20.

[0216] In step T19, the tilt cylinder 205 is moved a predetermined distance toward the fully extended position, and the loading platform 202 is rotated toward the upright position. In this case, the lift cylinder 206 maintains the extended state. In step T21, the control unit 230 determines whether the tilt cylinder 205 has moved to the fully extended position, that is, whether the loading platform 202 has moved to the upright position, based on whether or not the sensor 208 detects anything. If the tilt cylinder 205 has moved to the fully extended position, the process proceeds to step T22. On the other hand, if the tilt cylinder 205 has not moved to the fully extended position, the process in steps T15 to T21 is repeated until a positive determination is obtained.

[0217] In step T20, the tilt cylinder 205 is stopped, the movement of the loading platform 202 is halted, and an alarm is sounded by the buzzer 239 to notify the worker. In this case, the movement of the loading platform 202 is stopped midway, but if the worker removes the obstacle causing the alarm, the process in steps T15 to T21 is automatically resumed, and the movement of the loading platform 202 resumes. Alternatively, instead of automatic resumption, the process in steps T15 to T21 may be resumed by the worker operating a button or the like after removing the obstacle.

[0218] In step T22, the buzzer 239 notifies the operator that the tilt cylinder 205 has finished moving to its fully extended position, and the process proceeds to step T23. In step T23, it is determined whether or not the power unit 240 has been turned off, and if the off operation is confirmed, the process proceeds to step T24. In step T24, the scanning of the sensor head 220 is terminated, and the side cameras 221L and 221R are turned off, ending the flow.

[0219] Furthermore, when the present invention is applied to a loading platform lifting device as part of a frame, the following forms may be used. These modified forms will be explained with reference to Figures 33 to 35, 37, and 38. Figure 37 is a perspective view of the main part showing the caster stopper 270 of the loading platform 202 and a cross-sectional view thereof along the line X1-X1. Figure 38 is a flowchart showing an example of the operation of the loading platform lifting device 200.

[0220] In this modified example, the sensor head 220 (object image acquisition unit) shown in Figure 33, located on the upper part of the rear surface of the cargo box 209, acquires data on the object image of a part of the load-receiving platform lifting device 200 that changes shape, and the distance to that object image. Based on the acquisition results from the sensor head 220, the control unit 230 controls the drive actuators (tilt cylinder 205, lift cylinder 206) of the load-receiving platform lifting device 200. Specifically, in this modified example, the part of the load-receiving platform lifting device 200 that changes shape refers to the caster stopper 270 for preventing the fall of cargo or the trolley used to carry the cargo. As shown in Figure 37, this caster stopper 270 is located at the tip of the load-receiving platform 202 (Figures 33 to 35) of the load-receiving platform lifting device 200 in the modified example described above. The caster stopper 270 is located on the load-receiving platform body 202a that forms the cargo-placing surface of the load-receiving platform 202, and is movable between an upright state and a collapsed state.

[0221] In detail, the loading platform body 202a is made up of connected block-shaped members having a hollow section with the vehicle width direction as the longitudinal direction, and a caster stopper 270 is rotatably attached to the loading platform body 202a so as to open and close the hollow section 202b, which is open at the top. The caster stopper 270 is pivotally supported by a pin 270b, and its tip 270a has a bent shape.

[0222] The caster stopper 270 is held (secured) or released in a folded state via a lever 271 provided on the side of the loading platform body 202a. As shown in Figure 37(a), the lever 271 is configured to release the caster stopper 270 when positioned on one notch 272a of the fastener 272, and to secure it when positioned on the other notch 272b. Although the securing means are not shown, the lever 271 is connected to one end of a rod inserted through the side molding 202c, and the caster stopper 270 can be secured or released by engaging or disengaging a hook connected to the other end of the rod with an engaged portion provided on the front and rear ends of the caster stopper 270 on the vehicle side.

[0223] In this modified example, when the loading platform 202 is raised or lowered by the extension and retraction of the lift cylinder 206, the control unit 230 recognizes the caster stopper 270 of the loading platform 202 and checks the state of the caster stopper 270 (upright or retracted). If the caster stopper 270 is in the upright position, it is presumed that there is luggage or a trolley on the loading platform 202, so the system checks for the presence of luggage on the loading platform 202 and raises or lowers the loading platform 202. On the other hand, if the caster stopper 270 is in the retracted position, it is presumed that there is no luggage or a trolley on the loading platform 202, so the system stops the raising or lowering of the loading platform 202. This point will be explained with reference to the flowchart in Figure 38. The explanation above describes the case where the loading platform 202 is raised by the extension of the lift cylinder 206, but the same applies when the loading platform 202 is lowered by the contraction of the lift cylinder 206.

[0224] First, in step T31, the system remains in a standby state until the ACC power is turned on, or in other words, until power corresponding to the ACC power being turned on is input to the control unit 230. Then, once power is input, the system proceeds to step T32. In step T32, the control unit 230 performs initialization processing and proceeds to step T33.

[0225] In step T33, the control unit 230 determines whether or not an ON operation signal for the power unit 240 has been input to the control unit 230. If an ON operation signal is input, the process proceeds to step T34; if no ON operation signal is input, the process waits until such signals are input.

[0226] In step T34, the sensor head 220 performs scanning and recognizes the upright state of the caster stopper 270 (recognition of upright or downed state). This recognition process is substantially the same as in step T15 (Figure 36) of the modified example described above, and its explanation is omitted here.

[0227] In step T35, based on the recognition process in step T34, it is determined whether the caster stopper 270 is in an upright position. If the caster stopper 270 is in an upright position, it is presumed that there is luggage or a trolley on the loading platform 202, and the process proceeds to step T36. On the other hand, if the caster stopper 270 is in a downed position, it is presumed that there is no luggage or a trolley on the loading platform 202, and the process proceeds to step T39.

[0228] In step T36, the sensor head 220 performs a scan to confirm the presence or absence of an object on the loading platform 202. This recognition process is substantially the same as in step T15 (Figure 36) of the modified example described above, and is therefore omitted from this explanation. In step T37, the control unit 230 determines whether or not there is any cargo on the loading platform 202 based on the recognition process in step T36. In other words, if no object is found on the loading platform 202, it is presumed that no cargo is placed on the loading platform 202, and the process proceeds to step T39. On the other hand, if an object is found on the loading platform 202, it is presumed that cargo is placed on the loading platform 202, and the process proceeds to step T38.

[0229] In step T38, the control unit 230 extends the lift cylinder 206 by a predetermined distance toward its maximum extension position, and the loading platform 202 is raised. In step T40, based on the presence or absence of detection by the sensor 208, the control unit 230 determines whether the lift cylinder 206 has moved to its maximum extension position, that is, whether the loading platform 202 has moved to the raised position (the position shown by the solid line in Figure 34). If the lift cylinder 206 has moved to its maximum extension position, the process proceeds to step T41. On the other hand, if the lift cylinder 206 has not moved to its maximum extension position, the process in steps T34 to T40 is repeated until a positive determination is obtained.

[0230] In step T39, the drive of the lift cylinder 206 is stopped, the movement of the loading platform 202 is stopped, and an alarm sound is emitted by the buzzer 239 to notify the worker. In this case, the movement of the loading platform 202 is stopped midway, but if the worker resolves the cause of the alarm, the process in steps T34 to T40 is automatically resumed, and the movement of the loading platform 202 resumes. Alternatively, instead of automatic resumption control, the process in steps T34 to T40 may be resumed by operating a button or the like.

[0231] In step T41, the buzzer 239 notifies the operator that the lift cylinder 206 has moved to its fully extended position, and the process proceeds to step T42. In step T42, the control unit 230 determines whether the power unit 240 has been turned off, and after confirmation that the power unit has been turned off, the process proceeds to step T43. In step T43, the control unit 230 terminates the scanning of the sensor head 220 and ends the process.

[0232] Furthermore, the present invention can also be applied to feed transport vehicles, such as those disclosed in Japanese Patent Publication No. 2018-088898. When the present invention is applied to a feed transport vehicle, the following forms may be used. These modified forms will be described with reference to Figures 39 to 43. Figure 39 is a side view showing the feed transport vehicle 300. Figure 40 is a rear view showing the feed transport vehicle 300. Figure 41 is a rear view showing the feed transport vehicle 300 loading feed into the silo 350. Figure 42 is a plan view showing the oscillating operation of the discharge unit 311. Figure 43 is a flowchart showing an example of the operation of the feed transport vehicle 300.

[0233] As shown in Figures 39 and 40, the feed transport vehicle 300 has a drivable chassis 301 and a driver's cab 302. A feed storage tank 304 is mounted on the chassis 301 via a subframe 303. The feed storage tank 304 is long in the front-to-back direction, and for example, its interior is divided into four internal spaces from front to back, and each internal space is provided with an opening cover 305 that can be opened and closed. The internal spaces of the feed storage tank 304 contain feed, such as a mixture of nuts, wheat, hay, corn, milo, etc.

[0234] A bottom screw 306 is rotatably mounted at the bottom of the feed storage tank 304, extending forward and backward, allowing for selective transport of the feed from the feed storage tank 304 to the rear. The bottom screw 306 is rotated at a predetermined speed by a drive actuator, such as a hydraulic motor 306a, to transport the feed stored in the feed storage tank 304 backward while agitating it. In other words, the bottom screw 306 has spiral blades 306b that extend in a spiral shape, and when rotated in one direction, the feed is transported backward.

[0235] A vertical conveying section 309 is provided behind the feed storage tank 304, extending almost vertically. Inside this vertical conveying section 309 is a vertical screw 310 that vertically lifts the feed conveyed by the bottom screw 306. The vertical screw 310 is rotated at a predetermined speed by a drive actuator, such as a hydraulic motor 310a.

[0236] Furthermore, the rear end of the bottom screw 306 protrudes rearward from the rear surface of the feed storage tank 304, and the rear end of the bottom screw 306 is surrounded by a cylindrical section 313. At the part of this cylindrical section 313 that connects to the vertical conveying section 309, a confluence section 314 is provided that bulges horizontally from the cylindrical section 313. At this confluence section 314, the feed conveyed by the bottom screw 306 is sent to the vertical screw 310. In addition, the tip of a screw feeder section 319 for adding additives to the feed is connected to the cylindrical section 313. An additive hopper section 320 for introducing additives is provided at the base end of the screw feeder section 319.

[0237] A discharge unit 311, which houses a discharge screw 312, is connected to the upper part of the vertical conveying unit 309 so as to be rotatable in the vertical direction. For example, the discharge screw 312 is rotated at a predetermined speed by a drive actuator such as a hydraulic motor 312a. The discharge unit 311 is also raised and lowered by a luffing cylinder 311a, which is composed of a hydraulic cylinder, for example. This luffing motion makes it possible to adjust the height of the discharge port 311b provided at the tip of the discharge unit 311. The discharge screw 312 conveys the feed that has been conveyed by the vertical screw 310 to the tip of the discharge unit 311. Then, from the discharge port 311b at the tip of the discharge unit 311, the feed is fed into an inlet 351 of a silo 350 owned by a dairy farmer, for example, as shown in Figure 41.

[0238] Furthermore, the vertical transport unit 309 is made rotatable relative to the chassis 301 by driving a slewing motor 309a, which is composed of, for example, an electric motor. By driving the slewing motor 309a and rotating the vertical transport unit 309 relative to the chassis 301, the discharge unit 311 can swivel left and right, as shown in Figure 42, for example. This swivel motion makes it possible to adjust the horizontal position of the discharge port 311b of the discharge unit 311.

[0239] Furthermore, as shown in Figure 39, a sensor head 330 is provided near the discharge port 311b of the discharge unit 311. The sensor head 330 has substantially the same configuration as the sensor head 8 in the above embodiment. The sensor head 330 is configured to irradiate a laser beam as measurement light toward a predetermined area below the discharge port 311b of the discharge unit 311, and to receive the laser beam (reflected light) reflected by an object (see Figure 5, etc.). By scanning the area below the discharge port 311b of the discharge unit 311 with the laser pulse emitted from the sensor head 330, the vertical angle α and horizontal angle β of the laser pulse when the laser pulse is irradiated onto the measurement point P on the object are acquired as 3D polar coordinate data (distance D, vertical angle α, horizontal angle β), which is the position information of the measurement point P.

[0240] The sensor head 330 is connected to the control unit 340, and the 3D polar coordinate data (distance D, vertical angle α, horizontal angle β), which is the position information of the measurement point P acquired by the sensor head 330, is input to the control unit 340. The control unit 340 also has substantially the same functions as the laser control unit 8a in the above embodiment. Furthermore, the control unit 340 is connected to the hydraulic motor 306a of the bottom screw 306, the hydraulic motor 310a of the vertical screw 310, and the hydraulic motor 312a of the discharge screw 312. In addition, the control unit 340 is connected to the slewing motor 309a and the luffing cylinder 311a. Furthermore, the control unit 340 is connected to the buzzer 341.

[0241] In this modified example, the extension and retraction direction and amount of the luffing cylinder 311a, and the rotation direction and amount of the slewing motor 309a are controlled to ensure that the discharge port 311b of the discharge unit 311 is positioned above the inlet 351 of the silo 350, for example, as shown in Figure 42. This point will be explained with reference to the flowchart in Figure 43.

[0242] First, in step U11, it waits in a standby state until the ACC power supply is turned on, that is, until the power corresponding to the turning on of the ACC power supply is input to the control unit 340. When there is power input, it proceeds to step U12.

[0243] Next, in step U12, the control unit 340 performs scanning by the sensor head 330 to recognize the silo 350 and its inlet 351. As a prerequisite for this recognition process, the operator manually raises and lowers and turns the discharge unit 311 so that the discharge port 311b is approximately above the inlet 351 (so that the sensor head 330 is located above the inlet 351). Then, in substantially the same manner as the recognition process of the front wall 2b and the round bar 22 of the container 2 in the above embodiment (step S21 in FIG. 10), the control unit 340 performs the recognition process of the inlet 351. And in step U13, based on the data of the inlet 351 extracted in step U12, XYZ orthogonal coordinate data indicating the position of the inlet 351 is calculated.

[0244] Next, in step U14, the control unit 340 calculates the expansion / contraction direction and amount of the lifting cylinder 311a and the rotation direction and amount of the turning motor 309a necessary to move the discharge port 311b of the discharge unit 311 above the inlet 351 of the silo 350 at the position calculated in step U13.

[0245] In step U15, the control unit 340 drives the lifting cylinder 311a and the turning motor 309a by a predetermined amount smaller than the expansion / contraction amount and the rotation amount calculated in step U14, moves the discharge unit 311, and moves the discharge port 311b toward the charging start position where feed can be charged into the inlet 351 of the silo 350. The charging start position is set above the inlet 351 of the silo 350.

[0246] Next, in step U16, the control unit 340 performs an obstacle recognition process between the discharge unit 311 and the silo 350. This recognition process is substantially the same as the obstacle recognition process between the vehicle and the container 2 in the above embodiment (step S25 in FIG. 10), and the description thereof is omitted here. If it is determined that there is an obstacle (there is an obstacle with a certain area or more between the discharge unit 311 and the silo 350), the process proceeds to step U17. On the other hand, if it is determined that there is no obstacle, the process proceeds to step U18. In step U17, the control unit 340 stops the driving of the undulation cylinder 311a and the turning motor 309a to stop the movement of the discharge unit 311, and generates an alarm from the buzzer 341 to prompt the operator. Then, in step U18, if an alarm is being generated from the buzzer 341, the alarm is canceled and the process proceeds to step U19.

[0247] In step U19, it is determined by the control unit 340 whether the discharge port 311b of the discharge unit 311 has moved to the input start position where feed can be input into the input port 351 of the silo 350. In this case, based on the output value of a sensor (not shown), it is determined whether the undulation cylinder 311a and the turning motor 309a have been driven by the amount of expansion / contraction and the amount of rotation calculated in step U14. If the discharge port 311b has moved to the input start position, the process proceeds to step U20. On the other hand, if the discharge port 311b has not moved to the input start position, the processes of steps U15 to U19 are repeatedly performed until an affirmative determination is obtained (until the discharge port 311b moves to the input start position).

[0248] Note that in step U17, the movement of the discharge unit 311 is stopped halfway. However, if the operator removes the obstacle causing the alarm, etc., the processes of steps U15 to U19 are automatically restarted. On the other hand, instead of the control for automatic restart, after the operator removes the obstacle, etc., the processes of steps U15 to U19 may be restarted by operating a button or the like.

[0249] In step U20, hydraulic motors 306a, 310a, and 312a are driven to operate the bottom screw 306, the vertical screw 310, and the discharge screw 312. As a result, the feed in the feed storage tank 304 is transported by the bottom screw 306, the vertical screw 310, and the discharge screw 312, and the feed is fed from the discharge port 311b of the discharge section 311 toward the inlet 351 of the silo 350.

[0250] Next, in step U21, the sensor head 330 detects the surface 352 of the feed placed in the silo 350, and the control unit 340 determines whether or not there is an imbalance in the feed in the silo 350. In this case, the three-dimensional shape of the surface 352 of the feed placed in the silo 350 is recognized, and based on the recognized three-dimensional shape of the feed surface 352 (especially the variation in distance in the height direction), it is determined whether or not the surface 352 of the feed in the silo 350 is approximately horizontal. If the surface 352 of the feed in the silo 350 is approximately horizontal, it is determined that there is no imbalance in the feed in the silo 350, and the process proceeds to step U23. On the other hand, if the surface 352 of the feed in the silo 350 is not approximately horizontal but sloped, it is determined that there is an imbalance in the feed in the silo 350, and the process proceeds to step U22.

[0251] In step U22, the control unit 340 drives the swivel motor 309a, causing the discharge unit 311 to oscillate left and right. In other words, by driving the swivel motor 309a to rotate the vertical transport unit 309 relative to the chassis 301, the discharge unit 311 is rotated by a predetermined amount. This oscillating motion of the discharge unit 311 causes the slope of the feed surface 352 inside the silo 350 to become gentler, and the feed surface 352 inside the silo 350 approaches a nearly horizontal surface. The oscillating motion of the discharge unit 311 continues until a positive result is obtained in step U21, bringing the feed surface 352 inside the silo 350 closer to a nearly horizontal surface.

[0252] Next, in step U23, the sensor head 330 detects the surface 352 of the feed placed in the silo 350, and the control unit 340 determines whether the filling rate of the feed placed in the silo 350 is above a predetermined value. For example, if the difference between the distance to the top of the silo 350 and the distance to the surface 352 of the feed inside the silo 350 is less than a threshold, it is determined that the filling rate is above a predetermined value. If the filling rate of the feed inside the silo 350 is above a predetermined value, the process proceeds to step U24. On the other hand, if the filling rate of the feed inside the silo 350 is below a predetermined value, the process in steps U21 to U23 is repeated until a positive determination is obtained.

[0253] In step U24, the control unit 340 stops the hydraulic motors 306a, 310a, and 312a, stopping the bottom screw 306, the vertical screw 310, and the discharge screw 312, thus ending the flow. [Industrial applicability]

[0254] The present invention can be used in work vehicles that can load and unload cargo onto a chassis by the operation of a drive actuator on a body, or in work vehicles that can load transported cargo onto a chassis by the operation of a drive actuator on a body. [Explanation of symbols]

[0255] 1. Container handling vehicle (work vehicle) 2 containers (items to be handled) 3. Cargo handling equipment (bodywork) 8. Sensor head (object image acquisition unit) 35,36 Lift cylinder (drive actuator) 39. Slide cylinder (drive actuator) 70 Control Unit

Claims

1. A loading platform lifting device mounted on a vehicle, which rises and lowers between the loading platform floor and the ground for loading and unloading cargo, The vehicle comprises a loading platform supported at the end of a rotatable lift arm and rotating and moving up and down in a substantially horizontal position; a drive actuator that rotates the lift arm to raise and lower the loading platform; a control unit that controls the drive actuator; an operation unit located on the rear side of the vehicle that outputs a drive signal for the drive actuator to the control unit only when operated by an operator; and a sensor that detects when the loading platform has rotated and risen to a completed position at a height substantially equal to the loading platform floor and adjacent to the loading platform floor. When the operator located at the rear of the vehicle continues to operate the rotation and upward movement using the control unit, the loading platform rotates and rises, and as a result of this rotation and upward movement, the drive actuator extends by a predetermined distance, causing the loading platform to rotate and rise to the completed position. A loading platform lifting device characterized in that the loading platform can be visually confirmed by the worker when it is positioned at the completed position, and when the sensor detects that the loading platform has rotated and risen to the completed position, the notification unit to the worker is configured to start notifying the worker while the drive signal is being output.

2. In the loading platform lifting device according to claim 1, A loading platform lifting device characterized by further comprising an illumination unit that illuminates a predetermined area behind the vehicle.

3. A work vehicle characterized by being equipped with a loading platform lifting device as described in claim 1 or 2.

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