Cargo handling control device

Abstract

To provide a cargo handling control device capable of improving the success rate of cargo handling by a forklift.SOLUTION: A cargo handling control device 20 includes a guidance control unit 34 that controls a forklift 1 to approach a loading position P corresponding to the position of a pallet 11A to be loaded based on the position of the pallet 11A to be loaded relative to the forklift 1 when the forklift 1 is at the starting position P0, an approach determination unit 35 that determines whether the approach of the forklift 1 is successful or not based on the position of the pallet 11A to be loaded when the forklift 1 reaches the loading position P, and a re-guiding control unit 37 that controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be loaded relative to the forklift 1 if it is determined that the approach of the forklift 1 to the loading position P has failed.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a cargo handling control device. [Background technology]

[0002] Known as a conventional cargo handling control device is, for example, the technology described in Patent Document 1. The cargo handling control device described in Patent Document 1 detects the position and attitude of the transport object (target object) by a sensor when a forklift moves along a first path across an installation area in which the transport object (target object) is placed, with cargo loaded on a pallet, and sets a second path to a target position where the transport object has a predetermined position and attitude based on the position and attitude of the transport object, and moves the forklift along the second path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-70559 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above-mentioned conventional technology has the following problems. That is, the detection of the position of the target by the sensor may fail due to a detection error, although the probability is low. If the detection of the position of the target fails, even if the set route of the forklift is appropriate, the position of the forklift will deviate from the target, and it may not be possible to unload the pallet. Also, errors may occur in the estimation of the self-position of the forklift and in the guidance of the forklift due to obstacles, etc. If an estimation error in the self-position of the forklift or a guidance error occurs, the forklift will fail to approach the target, and the position of the forklift will deviate from the target, and it may not be possible to unload the pallet.

[0005] An object of the present invention is to provide a cargo handling control device that can improve the success rate of cargo handling by a forklift. [Means for solving the problem]

[0006] (1) One aspect of the present invention is a loading control device that moves a forklift from a start position toward a loading target to perform loading and unloading, and includes: an object detection unit that detects the loading target; a position calculation unit that calculates a position of the loading target relative to the forklift based on detection data from the object detection unit; an approach control unit that controls the forklift to approach a loading position corresponding to the loading target based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift is at the start position; an approach determination unit that determines whether the forklift has successfully approached the loading position based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position; a loading control unit that controls the forklift to perform loading and unloading on the loading target when the approach determination unit determines that the forklift has successfully approached the loading position; and a re-approach control unit that controls the forklift to approach the loading position again based on the position of the loading target relative to the forklift calculated by the position calculation unit when the approach determination unit determines that the forklift has failed to approach the loading position.

[0007] In such a loading control device, first, the object to be loaded is detected by the object detection unit at the start position, and the position of the object to be loaded relative to the forklift is calculated. Then, based on the position of the object to be loaded relative to the forklift, the forklift is controlled to approach the loading position corresponding to the object to be loaded. When the forklift reaches the loading position, the object detection unit detects the object to be loaded, and the position of the object to be loaded relative to the forklift is calculated. Then, based on the position of the object to be loaded relative to the forklift, it is determined whether the forklift has successfully approached the loading position. If it is determined that the forklift has failed to approach the loading position, the forklift is controlled to approach the loading position again based on the position of the object to be loaded relative to the forklift. In this way, if the forklift has failed to approach the loading position, the forklift is retried to approach the loading position, thereby increasing the probability that the forklift will reach an appropriate loading position corresponding to the object to be loaded. This improves the success rate of loading and unloading by the forklift.

[0008] (2) In (1) above, if it is determined that the forklift's approach to the loading position has failed, the re-approach control unit may control the forklift to temporarily retreat from the loading position and then re-approach the loading position based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift is at the loading position.

[0009] In this configuration, if the forklift fails to approach the loading position, the object is detected by the object detection unit at the loading position, and the position of the object relative to the forklift is calculated. Then, based on the position of the object relative to the forklift, the forklift is controlled to retreat from the loading position and then approach the loading position again. This allows the forklift to retry approaching the loading position while ensuring sufficient positional accuracy of the object relative to the forklift. This further increases the probability that the forklift will reach an appropriate loading position corresponding to the object.

[0010] (3) In (1) above, if the re-approach control unit determines that the forklift's approach to the loading position has failed, it may control the forklift to temporarily retreat from the loading position, and then control the forklift to re-approach the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit.

[0011] In this configuration, if the forklift fails to approach the loading position, the forklift is first controlled to retreat from the loading position. Then, based on the position of the loading object relative to the forklift, the forklift is controlled to approach the loading position again. This shortens the travel distance of the forklift after a travel route is set for retrying the forklift's approach to the loading position. This further increases the probability that the forklift will reach an appropriate loading position corresponding to the loading object.

[0012] (4) In (3) above, the re-approach control unit may control the forklift to temporarily retreat to a start position relative to the loading position, and then control the forklift to re-approach the loading position based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift is at the start position.

[0013] In such a configuration, if the forklift fails to approach the loading position, the forklift can be temporarily retreated to the start position that is known in advance as position information, thereby simplifying the process.

[0014] (5) In the above (1), the loading control device further includes a detection feasibility determination unit which determines whether the object detection unit is able to detect the loading object at the loading position when the approach determination unit determines that the approach of the forklift to the loading position has failed, and the re-approach control unit, when the detection feasibility determination unit determines that the object detection unit is able to detect the loading object at the loading position, controls the forklift to temporarily retreat to the loading position and then approach the loading position again based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the loading position, and when the detection feasibility determination unit determines that the object detection unit is not able to detect the loading object at the loading position, controls the forklift to temporarily retreat to the loading position, and then controls the forklift to approach the loading position again based on the position of the loading object relative to the forklift calculated by the position calculation unit.

[0015] In such a configuration, when the object detection unit can detect the loading object at the loading position, the forklift is controlled to retreat from the loading position and then re-approach the loading position based on the position of the loading object relative to the forklift at the loading position. When the object detection unit cannot detect the loading object at the loading position, the forklift is controlled to retreat from the loading position and then re-approach the loading position based on the position of the loading object relative to the forklift. In this way, by switching the retry method for the forklift's approach to the loading position depending on whether the object detection unit at the loading position can detect the loading object, the forklift's retry of approaching the loading position is appropriately performed depending on the usage environment.

[0016] (6) In (5) above, when the object detection unit determines that the object to be loaded cannot be detected, the re-approach control unit may control the forklift to temporarily retreat to a start position relative to the loading position, and then control the forklift to re-approach the loading position based on the position of the object to be loaded relative to the forklift calculated by the position calculation unit when the forklift is at the start position.

[0017] In such a configuration, when it is determined that the object detection unit is unable to detect the loading object, the forklift is temporarily retreated to a start position that is known in advance as position information, thereby simplifying processing.

[0018] (7) In any of (1) to (6) above, the forklift has a side shift cylinder that moves the forks in the left and right direction of the forklift, and the approach determination unit determines whether or not the amount of lateral slippage of the forklift relative to the loading object is equal to or less than a predetermined specified amount based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the loading position, and if the amount of lateral slippage of the forklift relative to the loading object is equal to or less than the specified amount, it may determine that the approach of the forklift to the loading position has been successful, and if the amount of lateral slippage of the forklift relative to the loading object is not equal to or less than the specified amount, it may determine that the approach of the forklift to the loading position has been unsuccessful.

[0019] In this configuration, when the lateral deviation of the forklift with respect to the loading target is equal to or less than a specified amount, it is determined that the forklift has successfully approached the loading target by moving the forks left and right using the side shift cylinders, and therefore it is not necessary to retry the forklift's approach to the loading target, which simplifies the process.

[0020] (8) In any of (1) to (7) above, the loading / unloading control device further includes a re-approach determination unit that determines whether the forklift has successfully re-approached the loading / unloading position based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position again, and a notification unit that issues an abnormality notification when the re-approach determination unit determines that the forklift has successfully re-approached the loading / unloading position. When the re-approach determination unit determines that the forklift has successfully re-approached the loading / unloading position, the loading / unloading control unit may control the forklift to perform loading / unloading on the loading target.

[0021] In such a configuration, if the forklift fails to re-approach the loading position, an abnormality notification can be sent to inform those in the vicinity that the forklift has failed to approach the loading position twice in a row and loading will be stopped.

[0022] (9) In any one of the above (1) to (8), the object detection unit may detect the object while the forklift is facing the object.

[0023] In this configuration, when the forklift is in either the start position or the loading position, the object detection unit detects the loading object with the forklift facing the loading object, thereby minimizing the number of object detection units used and reducing costs.

[0024] (10) In any of (1) to (8) above, the object detection unit may include a first detection unit that detects the object to be loaded when the forklift is facing sideways toward the object to be loaded, and a second detection unit that detects the object to be loaded when the forklift is facing frontward toward the object to be loaded, and the position calculation unit may calculate the position of the object to be loaded relative to the forklift based on detection data from the first detection unit when the forklift is in the starting position, and may calculate the position of the object to be loaded relative to the forklift based on detection data from the second detection unit when the forklift is in the loading position.

[0025] In this configuration, when the forklift is in the starting position, the first detection unit detects the object while the forklift is facing the side of the object. Then, the forklift is controlled to approach the loading position. Therefore, even if the space in front of the object is narrow, the forklift can be driven to the loading position corresponding to the object to load the object.

[0026] (11) In any of (1) to (10) above, the loading object is a pallet having a pair of fork holes into which a pair of left and right forks of a forklift are inserted, the position calculation unit calculates a position and attitude of the pallet relative to the forklift based on detection data from the object detection unit, the approach control unit controls the forklift to approach a loading position corresponding to the position of the pallet based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift is at the start position, the approach determination unit determines whether the forklift has successfully approached the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position, and the loading control unit controls the forklift to retrieve the pallet as loading if the approach determination unit determines that the forklift has successfully approached the loading position, and the re-approach control unit controls the forklift to approach the loading position again based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit if the approach determination unit determines that the forklift has failed to approach the loading position.

[0027] In this configuration, if the forklift fails to approach the loading position, the forklift will retry the approach to the loading position, increasing the probability that the forklift will reach the appropriate loading position corresponding to the position of the pallet to be loaded, thereby improving the success rate of loading by the forklift.

[0028] (12) In the above (11), the cargo handling control device further includes a loading feasibility determination unit that determines whether the forklift is likely to be able to successfully load the pallet by re-approaching the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position when the approach determination unit determines that the forklift's approach to the loading position has failed, and an abnormality stop control unit that controls the forklift to abnormally stop the forklift when the loading feasibility determination unit determines that the forklift is likely to be able to successfully load the pallet even if it re-approaches the loading position, and the re-approach control unit may control the forklift to re-approach the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the loading feasibility determination unit determines that the forklift is likely to be able to successfully load the pallet by re-approaching the loading position.

[0029] In this configuration, if it is determined that the forklift has failed to approach the loading position, and if it is determined that there is no possibility of the forklift successfully picking up the pallet even if it re-approaches the loading position, the forklift is brought to an abnormal stop, which eliminates the need to retry the forklift's approach, thereby reducing the total loading time.

[0030] (13) In (12) above, the forklift has a side shift cylinder that moves the forks in the left and right directions of the forklift, and the approach determination unit determines whether a first condition is met, where a roll angle of the forklift relative to the pallet is equal to or less than a predetermined first specified angle, a second condition is met, where a pitch angle of the forklift relative to the pallet is equal to or less than a predetermined second specified angle, a third condition is met, where a lateral deviation of the forklift relative to the pallet is equal to or less than a predetermined specified amount, and a fourth condition is met, where a yaw angle of the forklift relative to the pallet is equal to or less than a predetermined third specified angle. If all of the first, second, third and fourth conditions are met, it may be determined that the approach of the forklift to the loading position is successful, and if any of the first, second, third and fourth conditions are not met, it may be determined that the approach of the forklift to the loading position is unsuccessful.

[0031] In this configuration, if the position or posture of the pallet to be loaded relative to the forklift deviates by a certain amount or more, it is determined that the forklift has failed to approach the loading position. Therefore, the success or failure of the forklift's approach to the loading position is appropriately determined.

[0032] (14) In (13) above, the loading feasibility determination unit may determine that there is a possibility that the forklift will be able to successfully load the pallet by re-approaching the loading position when the first condition and the second condition are satisfied, and may determine that there is no possibility that the forklift will be able to successfully load the pallet by re-approaching the loading position when either the first condition or the second condition is not satisfied.

[0033] With this configuration, for example, if the pallet to be loaded is tilted and the roll angle of the forklift relative to the pallet to be loaded exceeds a first specified angle, or the pitch angle of the forklift relative to the pallet to be loaded exceeds a second specified angle, there is no need to perform unnecessary retries of the forklift approach.

[0034] (15) In any of (11) to (14) above, the loading control device further includes a re-approach determination unit which determines whether the forklift has successfully re-approached the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position again, and if the re-approach determination unit determines that the forklift has failed to re-approach the loading position, the re-approach control unit controls the forklift to re-approach the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit, and if the re-approach determination unit determines that the forklift has successfully re-approached the loading position, the loading control unit may control the forklift to unload the pallet.

[0035] In this configuration, if the forklift fails to re-approach the loading position, the forklift will retry the approach to the loading position, increasing the probability that the forklift will reach the appropriate loading position corresponding to the position of the pallet to be loaded, thereby further improving the success rate of loading by the forklift.

[0036] (16) In (15) above, the loading and unloading control device may further include a re-approach count determination unit which determines whether the number of forklift re-approaches to the loading and unloading position has reached a predetermined upper limit value when the re-approach determination unit determines that the forklift has failed to re-approach the loading and unloading position, and an abnormality stop control unit which controls the forklift to abnormally stop traveling when the re-approach count determination unit determines that the number of forklift re-approaches to the loading and unloading position has reached the upper limit value.

[0037] In this configuration, when the number of retries of the forklift to approach the loading position reaches the upper limit, the forklift is stopped abnormally, so that the forklift does not have to retry the approach more than necessary, thereby reducing the total loading time. Effect of the Invention

[0038] According to the present invention, the success rate of loading and unloading by a forklift can be improved. [Brief description of the drawings]

[0039] [Figure 1] 1 is a side view showing a forklift to which a cargo handling control device according to an embodiment of the present invention is applied. [Diagram 2] 1 is a block diagram showing a configuration of a cargo handling control device according to a first embodiment of the present invention. [Diagram 3] FIG. 2 is a schematic plan view showing an operation of a forklift moving from a start position to a loading position and picking up a load. [Figure 4] 3 is a flowchart showing a procedure of an item-receiving control process executed by a controller shown in FIG. 2. [Diagram 5] 5 is a flowchart showing details of step S111 shown in FIG. 4. [Figure 6] 11 is a schematic plan view showing an operation of retrying an approach of a forklift to a loading position when the forklift has failed to approach the loading position; FIG. [Figure 7] FIG. 5 is a block diagram showing the configuration of a cargo handling control device according to a second embodiment of the present invention. [Figure 8] 8 is a flowchart showing a procedure of an item-receiving control process executed by a controller shown in FIG. 7. [Figure 9] 11 is a schematic plan view showing an operation of retrying an approach of a forklift to a loading position when the forklift has failed to approach the loading position; FIG. [Figure 10]FIG. 11 is a block diagram showing the configuration of a cargo handling control device according to a third embodiment of the present invention. [Figure 11] 11 is a flowchart showing a procedure of an item-receiving control process executed by a controller shown in FIG. [Figure 12] This is a schematic plan view showing the operation of retrying the forklift's approach to the loading position when the forklift's approach to the loading position fails and it is determined that the camera at the loading position is unable to detect the pallet to be loaded. [Figure 13] FIG. 11 is a block diagram showing the configuration of a cargo handling control device according to a fourth embodiment of the present invention. [Figure 14] 14 is a flowchart showing a procedure of an item-receiving control process executed by a controller shown in FIG. 13. [Figure 15] FIG. 2 is a schematic plan view showing an operation of a forklift moving from a start position to a loading position and performing loading and unloading. [Figure 16] This is a schematic plan view showing the operation of retrying the forklift's approach to the loading position when the forklift's approach to the loading position fails and it is determined that the camera at the loading position can detect the pallet to be loaded. [Figure 17] This is a schematic plan view showing the operation of retrying the forklift's approach to the loading position when the forklift's approach to the loading position fails and it is determined that the camera at the loading position is unable to detect the pallet to be loaded. [Figure 18] FIG. 13 is a block diagram showing the configuration of a cargo handling control device according to a fifth embodiment of the present invention. [Figure 19] 20 is a flowchart showing a procedure for a cargo unloading control process executed by a controller shown in FIG. 18. [Figure 20] This figure (including plan and front views) shows an example of a pattern in which the success rate of cargo pickup increases by retrying the forklift approach, and an example of a pattern in which the success rate of cargo pickup does not increase even by retrying the forklift approach. [Figure 21] 20 is a flowchart showing details of steps S111 and S131 shown in FIG. 19. [Figure 22] FIG. 1 is a diagram (including a plan view, a front view, and a cross-sectional view) showing a state in which a forklift fails to approach a loading position. [Diagram 23] FIG. 2 is a perspective view showing the dimensions of the fork holes and forks of the pallet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, the same or equivalent elements are designated by the same reference numerals, and duplicated explanations will be omitted.

[0041] Fig. 1 is a side view showing a forklift to which a cargo handling control device according to an embodiment of the present invention is applied. In Fig. 1, the forklift 1 is a reach forklift. Here, the front-rear direction of the forklift 1 is defined as the X-axis direction, the left-right direction (lateral direction) of the forklift 1 is defined as the Y-axis direction, and the up-down direction (height direction) of the forklift 1 is defined as the Z-axis direction (see Fig. 22). The forklift 1 is equipped with a traveling device 2 and a cargo handling device 3.

[0042] The traveling device 2 has a body 4, a pair of left and right reach legs 5 extending forward from the bottom of the body 4, left and right front wheels 6 disposed at the tip (front end) of each reach leg 5, and rear wheels 7 serving as drive wheels and steering wheels disposed at the left rear part of the body 4. Caster wheels (not shown) are disposed at the right rear part of the body 4.

[0043] The loading device 3 has a mast 8 that is disposed between each reach leg 5 and is movable along the reach leg 5 in the fore-and-aft direction (X-axis direction) of the vehicle body 4, a pair of left and right forks 12 that are attached to the mast 8 via a lift bracket 9 and a load bracket 10 so as to be able to be raised and lowered in the vertical direction (Z-axis direction) and hold a pallet 11, a lift cylinder 13 that raises and lowers the forks 12 via the lift bracket 9 and the load bracket 10, a reach cylinder 14 (see Figure 2) that moves the mast 8 in the fore-and-aft direction of the vehicle body 4, thereby moving the forks 12 (advancing and retreating) in the fore-and-aft direction of the vehicle body 4, and a side shift cylinder 15 (see Figure 2) that moves the forks 12 laterally (Y-axis direction) via the load bracket 10.

[0044] The pallet 11 is, for example, a flat pallet made of plastic or wood. The pallet 11 has a square or approximately square shape in a plan view. A cargo M is placed on the pallet 11. The pallet 11 is provided with a pair of fork holes 11a (see FIG. 20(b)) into which the forks 12 are inserted.

[0045] 2 is a block diagram showing the configuration of a cargo handling control device according to a first embodiment of the present invention. In FIG. 2, a cargo handling control device 20 of this embodiment is a device that performs cargo handling by automatically driving a forklift 1.

[0046] As shown in Fig. 3, the cargo handling control device 20 unloads the pallet 11 loaded on the bed 18 of the truck 17, i.e., performs so-called cargo handling. The cargo handling control device 20 moves the forklift 1 from a start position P0 toward the pallet 11 to be handled (hereinafter, referred to as the pallet to be handled 11A) to carry out cargo handling. The pallet to be handled 11A is the cargo handling target. The start position P0 is a position to the side of the truck 17 where the forklift 1 starts moving toward the pallet to be handled 11A.

[0047] The cargo handling control device 20 includes a camera 21, a laser sensor 22, a map storage unit 23, a traveling drive unit 24, a lift drive unit 25, a reach drive unit 26, a side shift drive unit 27, an alarm 28, and a controller 30. These are mounted on the forklift 1.

[0048] The camera 21 is an image sensor that captures an image of a predetermined angle range (angle of view θ) including the area in front of the forklift 1 and outputs image data. The camera 21 captures an image of the pallet 11 loaded on the loading platform 18 of the truck 17. The camera 21 constitutes an object detection unit that detects the pallet 11A to be removed. The camera 21 detects the pallet 11A to be removed while the forklift 1 is facing forward toward the pallet 11A to be removed, and outputs image data that is detection data.

[0049] The laser sensor 22 irradiates a laser around the forklift 1 and receives reflected laser light to detect the distance to an object present around the forklift 1 and output detection data. As the laser sensor 22, for example, a LIDAR (light detection and ranging) or a laser range finder is used.

[0050] The map storage unit 23 stores map data of an area where cargo handling is performed by the forklift 1. The map data includes buildings, pillars, shelves, walls, etc. The map data is created in advance by the laser sensor 22.

[0051] The traveling drive unit 24 is a drive unit that drives the forklift 1. The traveling drive unit 24 has, for example, a traveling motor that rotates the rear wheels 7 and a steering motor that steers the rear wheels 7, although not shown.

[0052] The lift drive unit 25 is a drive unit that extends and retracts the lift cylinder 13. The lift drive unit 25 is, for example, an electromagnetic control valve (not shown) disposed between a hydraulic pump and the lift cylinder 13.

[0053] The reach drive unit 26 is a drive unit that extends and retracts the reach cylinder 14. The reach drive unit 26 is, for example, an electromagnetic control valve (not shown) that is arranged between a hydraulic pump and the reach cylinder 14.

[0054] The side shift drive unit 27 is a drive unit that extends and retracts the side shift cylinder 15. The side shift drive unit 27 is, for example, an electromagnetic control valve (not shown) that is disposed between a hydraulic pump and the side shift cylinder 15.

[0055] The alarm device 28 is a device that issues an alarm when an abnormality occurs during loading and unloading operations. The alarm device 28 issues an alarm by sounding or displaying an alarm.

[0056] The controller 30 is composed of a CPU, RAM, ROM, an input / output interface, etc. The controller 30 has a pallet position calculation unit 31, a self-position estimation unit 32, a route generation unit 33, a guidance control unit 34, an approach determination unit 35, a re-route generation unit 36, a re-guiding control unit 37, a re-approach determination unit 38, a cargo handling control unit 39, and an alarm control unit 40.

[0057] The pallet position calculation unit 31 calculates the position and orientation of the target pallet 11A relative to the forklift 1 based on image data from the camera 21. The pallet position calculation unit 31 calculates the position and orientation of the target pallet 11A relative to the forklift 1 at the start position P0 and the handling position P. The handling position P is a position corresponding to the target pallet 11A. Specifically, the handling position P is a position in front of the target pallet 11A. The pallet position calculation unit 31 constitutes a position calculation unit that calculates the position of the target pallet 11A relative to the forklift 1.

[0058] The self-position estimation unit 32 estimates the self-position of the forklift 1 based on the detection data of the laser sensor 22 and the map data stored in the map storage unit 23. Specifically, the self-position estimation unit 32 matches the detection data of the laser sensor 22 with the map data using, for example, a SLAM (simultaneous localization and mapping) method to estimate the self-position of the forklift 1. SLAM is a self-position estimation technology that estimates the self-position using sensor data and map data.

[0059] The path generating unit 33 generates a travel path D (see FIG. 3(a)) from the start position P0 to the loading position P based on the position and attitude of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculating unit 31 and the self-position of the forklift 1 estimated by the self-position estimating unit 32. The path generating unit 33 generates a travel path D that moves the forklift 1 forward from the start position P0 to the loading position P.

[0060] The guidance control unit 34 controls the traveling drive unit 24 to guide the forklift 1 to the loading position P according to the traveling route D generated by the route generation unit 33 based on the self-position of the forklift 1 estimated by the self-position estimation unit 32.

[0061] The guidance control unit 34, in cooperation with the self-position estimation unit 32 and the route generation unit 33, constitutes an approach control unit that controls the forklift 1 to approach the loading position P corresponding to the position of the pallet 11A to be loaded, based on the position of the pallet 11A to be loaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 is at the start position P0.

[0062] The approach determination unit 35 determines whether the approach of the forklift 1 to the loading position P is successful based on the position and posture of the pallet 11A to be loaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 reaches the loading position P.

[0063] When the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed, the re-route generation unit 36 ​​regenerates a travel route to the loading position P based on the position and attitude of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculation unit 31 at the loading position P and the self-position of the forklift 1 estimated by the self-position estimation unit 32. The re-route generation unit 36 ​​generates a travel route that moves the forklift 1 backward once from the loading position P and then forward toward the loading position P (see FIG. 6).

[0064] The re-guiding control unit 37 controls the traveling drive unit 24 to re-guide the forklift 1 to the loading position P according to the traveling route generated by the re-route generating unit 36 ​​based on the self-position of the forklift 1 estimated by the self-position estimating unit 32.

[0065] The re-guiding control unit 37, in cooperation with the self-position estimation unit 32 and the re-route generation unit 36, constitutes a re-approach control unit that controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be unloaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed.

[0066] If the re-approach control unit determines that the approach of the forklift 1 to the loading position P has failed, the re-approach control unit controls the forklift 1 to temporarily retreat from the loading position P and then re-approach the loading position P based on the position of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 is at the loading position P.

[0067] The re-approach determination unit 38 determines whether the forklift 1 has successfully re-approached the loading position P based on the position and posture of the pallet 11A to be unloaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 reaches the loading position P again.

[0068] When the approach determination unit 35 determines that the forklift 1 has successfully approached the loading position P, the loading control unit 39 controls the lift drive unit 25, the reach drive unit 26, and the side shift drive unit 27 to load the load onto the target pallet 11A. When the re-approach determination unit 38 determines that the forklift 1 has successfully re-approached the loading position P, the loading control unit 39 controls the lift drive unit 25, the reach drive unit 26, and the side shift drive unit 27 to load the load onto the target pallet 11A.

[0069] The warning control unit 40 issues a warning by outputting an abnormality notification signal to the alarm 28 when the re-approach determination unit 38 determines that the forklift 1 has failed to re-approach the loading position P. The warning control unit 40 constitutes a notification unit that issues an abnormality notification when the re-approach determination unit 38 determines that the forklift 1 has failed to re-approach the loading position P.

[0070] Fig. 4 is a flowchart showing the procedure of the goods-receiving control process executed by the controller 30. This process is executed when the forklift 1 reaches the start position P0, as shown in Fig. 3(a). When the forklift 1 reaches the start position P0, it faces the front of the goods-receiving target pallet 11A, and the goods-receiving target pallet 11A can be recognized by the camera 21.

[0071] 4, the controller 30 first acquires image data from the camera 21 (step S101). Then, the controller 30 calculates the position and attitude of the target pallet 11A relative to the forklift 1 based on the image data from the camera 21 (step S102).

[0072] Next, the controller 30 estimates the self-position of the forklift 1 based on the detection data of the laser sensor 22 and the map data stored in the map storage unit 23 (step S103). Next, the controller 30 generates a travel route D from the start position P0, which is the current position of the forklift 1, to the loading position P, as shown in Fig. 3(a) (step S104). Next, the controller 30 controls the travel drive unit 24 to make the forklift 1 approach the loading position P according to the travel route D (step S105).

[0073] Next, the controller 30 estimates the own position of the forklift 1 based on the detection data of the laser sensor 22 and the map data (step S106). Then, the controller 30 judges whether the forklift 1 has reached the loading position P based on the own position of the forklift 1 (step S107). When the controller 30 judges that the forklift 1 has not reached the loading position P, it executes the above step S105 again.

[0074] 3(b), when the controller 30 determines that the forklift 1 has reached the loading position P, the controller 30 controls the travel drive unit 24 to stop the travel of the forklift 1 (step S108). Next, the controller 30 acquires image data from the camera 21 (step S109). Then, the controller 30 calculates the position and attitude of the target pallet 11A relative to the forklift 1 based on the image data from the camera 21 (step S110).

[0075] Next, the controller 30 determines whether the approach of the forklift 1 to the loading position P has been successful, based on the position and attitude of the target pallet 11A relative to the forklift 1 (step S111).

[0076] Fig. 5 is a flowchart showing the details of step S111. In Fig. 5, the controller 30 determines whether the amount of lateral deviation of the forklift 1 with respect to the target pallet 11A is equal to or less than a predetermined amount based on the position of the target pallet 11A with respect to the forklift 1 (step S151).

[0077] The lateral deviation of the forklift 1 is the deviation in the lateral direction (left-right direction) of the forklift 1. The specified amount is a value set so that the forks 12 can be inserted into the fork holes 11a of the target pallet 11A by moving the forks 12 in the lateral direction by the side shift cylinders 15. The specified amount is, for example, the maximum lateral movement amount of the forks 12 from the center position of the forklift 1 in the left-right direction.

[0078] When the controller 30 determines that the amount of lateral deviation of the forklift 1 relative to the pallet 11A to be picked up is less than or equal to a specified amount, it determines, based on the posture of the pallet 11A to be picked up, whether the deviation angle of the forklift 1 relative to the pallet 11A to be picked up is less than or equal to a predetermined specified angle (step S152).

[0079] The deviation angle of the forklift 1 is the deviation amount of the yaw angle of the forklift 1. The specified angle is set so that the forks 12 can be inserted into the fork holes 11a of the target pallet 11A by moving the forks 12 laterally using the side shift cylinders 15.

[0080] When the controller 30 determines that the deviation angle of the forklift 1 with respect to the loading target pallet 11A is equal to or smaller than the specified angle, it determines that the forklift 1 has successfully approached the loading position P (step S153).

[0081] When the controller 30 determines in step S151 that the amount of lateral deviation of the forklift 1 relative to the pallet 11A to be loaded is not equal to or less than a specified amount, or when the controller 30 determines in step S152 that the deviation angle of the forklift 1 relative to the pallet 11A to be loaded is not equal to or less than a specified angle, it determines that the approach of the forklift 1 to the loading position P has failed (step S154).

[0082] Returning to Fig. 4, when the controller 30 determines in step S111 that the approach of the forklift 1 to the loading position P has been successful, it controls the lift drive unit 25 and the side shift drive unit 27 to align the forks 12 with the fork holes 11a of the target pallet 11A (step S112). Then, as shown in Fig. 3(c), the controller 30 controls the reach drive unit 26 and the lift drive unit 25 to insert the forks 12 into the fork holes 11a of the target pallet 11A to load the target pallet 11A (step S113).

[0083] When the controller 30 determines in step S111 that the approach of the forklift 1 to the loading position P has failed, it estimates the own position of the forklift 1 based on the detection data of the laser sensor 22 and the map data stored in the map memory unit 23 (step S114).

[0084] Next, the controller 30 generates again a travel route from the current position of the forklift 1 to the loading position P as shown in Fig. 6 (step S115). At this time, the controller 30 generates a travel route that moves the forklift 1 backward a predetermined amount from the current position and then forward. Next, the controller 30 controls the traveling drive unit 24 to make the forklift 1 approach the loading position P again according to the travel route (step S116).

[0085] Next, the controller 30 estimates the own position of the forklift 1 based on the detection data of the laser sensor 22 and the map data (step S117). Then, the controller 30 judges whether the forklift 1 has reached the loading position P based on the own position of the forklift 1 (step S118). When the controller 30 judges that the forklift 1 has not reached the loading position P, it executes the above step S116 again.

[0086] When the controller 30 determines that the forklift 1 has reached the loading position P, it controls the travel drive unit 24 to stop the travel of the forklift 1 (step S119). Next, the controller 30 acquires image data from the camera 21 (step S120). Then, the controller 30 calculates the position and attitude of the target pallet 11A relative to the forklift 1 based on the image data from the camera 21 (step S121).

[0087] Next, the controller 30 determines whether the forklift 1 has successfully re-approached the loading position P based on the position and attitude of the target pallet 11A relative to the forklift 1 (step S122). Details of step S122 are the same as those of step S111 described above.

[0088] When the controller 30 determines that the re-approach of the forklift 1 to the loading position P is successful, the controller 30 executes the above-mentioned step S112. When the controller 30 determines that the re-approach of the forklift 1 to the loading position P is unsuccessful, the controller 30 outputs an abnormality notification signal to the alarm 28 (step S123).

[0089] Here, the pallet position calculation unit 31 executes procedures S101, S102, S109, S110, S120, and S121. The self-position estimation unit 32 executes procedures S103, S106, S114, and S117. The route generation unit 33 executes procedure S104. The guidance control unit 34 executes procedures S105 to S108. The approach determination unit 35 executes procedure S111. The re-route generation unit 36 ​​executes procedure S115. The re-guiding control unit 37 executes procedures S116 to S119. The re-approach determination unit 38 executes procedure S122. The loading and unloading control unit 39 executes procedures S112 and S113. The warning control unit 40 executes procedure S123.

[0090] In the cargo handling control device 20 as described above, the forklift 1 performing cargo handling travels toward a truck 17 having a pallet 11 loaded on its loading platform 18, as shown in Figure 3(a), and stops at a starting position P0 a certain distance away from the side of the truck 17, facing directly toward the pallet 11A to be handled.

[0091] In this state, the target pallet 11A is imaged by the camera 21. Then, based on the image data of the camera 21, the position and attitude of the target pallet 11A relative to the forklift 1 are calculated, and a travel route D to a loading position P in front of the target pallet 11A is generated. Then, the forklift 1 approaches the loading position P along the travel route D.

[0092] 3(b), when the forklift 1 reaches the loading position P, the camera 21 captures an image of the target pallet 11A. Then, based on the image data from the camera 21, the position and attitude of the target pallet 11A relative to the forklift 1 are calculated, and based on the calculation result, it is determined whether the forklift 1 has successfully approached the loading position P.

[0093] When the forklift 1 successfully approaches the loading position P, the pallet 11A to be loaded is loaded, as shown in Fig. 3(c). Specifically, the forks 12 of the forklift 1 are inserted into the fork holes 11a of the pallet 11A to be loaded, and the forks 12 are raised in this state, so that the pallet 11A to be loaded is held by the forks 12. Then, the forklift 1 transports the pallet 11A to be loaded to the designated location.

[0094] On the other hand, as shown in Fig. 6(a), when the forklift 1 fails to approach the loading position P due to deviation of the forklift 1 from the target pallet 11A, a new travel route to the loading position P is generated. Then, the forklift 1 approaches the loading position P again along the new travel route as shown in Figs. 6(b) and (c).

[0095] If the forklift 1 is successful in re-approaching the loading position P, the loading target pallet 11A is unloaded. If the forklift 1 is also unsuccessful in re-approaching the loading position P, an alarm is issued by the alarm 28.

[0096] As described above, in this embodiment, the camera 21 first detects the pallet 11A to be picked up at the start position P0, and the position of the pallet 11A to be picked up relative to the forklift 1 is calculated. Then, based on the position of the pallet 11A to be picked up relative to the forklift 1, the forklift 1 is controlled to approach the loading position P corresponding to the position of the pallet 11A to be picked up. When the forklift 1 reaches the loading position P, the camera 21 detects the pallet 11A to be picked up, and the position of the pallet 11A to be picked up relative to the forklift 1 is calculated. Then, based on the position of the pallet 11A to be picked up relative to the forklift 1, it is determined whether the approach of the forklift 1 to the loading position P was successful. If it is determined that the approach of the forklift 1 to the loading position P has failed, the forklift 1 is controlled to approach the loading position P again based on the position of the pallet 11A to be picked up relative to the forklift 1. In this way, if the forklift 1 fails to approach the loading position P, the forklift 1 can retry the approach to the loading position P, thereby increasing the probability that the forklift 1 will reach the appropriate loading position P that corresponds to the position of the pallet 11A to be picked up. This improves the success rate of loading by the forklift 1.

[0097] Furthermore, in this embodiment, if it is determined that the approach of the forklift 1 to the loading position P is successful, loading is performed on the target pallet 11A. Therefore, the travel distance of the forklift 1 becomes long only if the approach of the forklift 1 to the loading position P is unsuccessful. Therefore, the travel time of the forklift 1 can be reduced.

[0098] In this embodiment, if the forklift 1 fails to approach the loading position P, the camera 21 detects the target pallet 11A at the loading position P, and the position of the target pallet 11A relative to the forklift 1 is calculated. Then, based on the position of the target pallet 11A relative to the forklift 1, the forklift 1 is controlled to temporarily retreat from the loading position P and then approach the loading position P again. Therefore, the forklift 1 retry approaching the loading position P while sufficiently ensuring the positional accuracy of the target pallet 11A relative to the forklift 1. This further increases the probability that the forklift 1 will reach the appropriate loading position P corresponding to the position of the target pallet 11A.

[0099] In this embodiment, when the amount of lateral deviation of the forklift 1 from the target pallet 11A is equal to or less than a specified amount, it is determined that the forks 12 can be moved left and right by the side shift cylinders 15 to adjust the forks 12 to an appropriate position with respect to the target pallet 11A, and the approach of the forklift 1 to the loading position P is successful. Therefore, since it is not necessary to retry the approach of the forklift 1 to the loading position P, the processing of the controller 30 can be simplified.

[0100] In addition, in this embodiment, if the forklift 1 fails to re-approach the loading position P, an abnormality notification can be sent to inform those in the vicinity that the forklift 1 has failed to approach the loading position P twice in a row and therefore loading will be discontinued.

[0101] Furthermore, in this embodiment, the camera 21 detects the target pallet 11A with the forklift 1 facing the target pallet 11A, whether the forklift 1 is at the start position P0 or the loading position P. Therefore, the number of cameras 21 used is kept to a minimum, which contributes to cost reduction.

[0102] Fig. 7 is a block diagram showing the configuration of a cargo handling control device according to a second embodiment of the present invention. In Fig. 7, a cargo handling control device 20A of this embodiment includes a controller 30A instead of the controller 30 in the first embodiment.

[0103] The controller 30A has a pallet position calculation unit 31, a self-position estimation unit 32, a route generation unit 33, a guidance control unit 34, an approach determination unit 35, an evacuation control unit 41, a re-route generation unit 36A, a re-guidance control unit 37A, a re-approach determination unit 38, a loading and unloading control unit 39, and an alarm control unit 40.

[0104] When the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed, the evacuation control unit 41 controls the traveling drive unit 24 to temporarily evacuate the forklift 1 to the loading position P. The evacuation control unit 41 controls the traveling drive unit 24 to temporarily evacuate the forklift 1 to the start position P0 from the loading position P.

[0105] When the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed, the re-route generation unit 36A regenerates a travel route to the loading position P based on the position and attitude of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculation unit 31 at the start position P0 and the self-position of the forklift 1 estimated by the self-position estimation unit 32. Similar to the route generation unit 33, the re-route generation unit 36A generates a travel route that moves the forklift 1 forward toward the loading position P.

[0106] The re-guiding control unit 37A controls the traveling drive unit 24 to re-guide the forklift 1 to the loading position P according to the traveling route generated by the re-route generating unit 36A based on the self-position of the forklift 1 estimated by the self-position estimating unit 32.

[0107] The re-guiding control unit 37A works in cooperation with the self-position estimation unit 32, the evacuation control unit 41 and the re-route generation unit 36A to constitute a re-approach control unit that controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be unloaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed.

[0108] If the re-approach control unit determines that the approach of the forklift 1 to the loading position P has failed, it controls the forklift 1 to temporarily retreat to the start position P0 relative to the loading position P, and then controls the forklift 1 to re-approach the loading position P based on the position of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 is at the start position P0.

[0109] Fig. 8 is a flow chart showing the procedure of the cargo unloading control process executed by the controller 30A, and corresponds to Fig. 4. In Fig. 8, the controller 30A executes steps S101 to S111 in the same manner as in the first embodiment.

[0110] If the controller 30A determines in step S111 that the approach of the forklift 1 to the loading position P has failed, it controls the traveling drive unit 24 so that the forklift 1 returns to the starting position P0, as shown in Figures 9(a) and (b) (step S125).

[0111] Next, the controller 30A acquires image data from the camera 21 (step S126). Then, the controller 30A calculates the position and attitude of the target pallet 11A relative to the forklift 1 based on the image data from the camera 21 (step S127). Next, the controller 30A executes step S114 in the same manner as in the first embodiment.

[0112] Next, the controller 30A generates again a travel route from the start position P0, which is the current position of the forklift 1, to the loading position P (step S115A). Next, the controller 30A controls the traveling drive unit 24 so as to make the forklift 1 approach the loading position P again along the travel route (step S116A). Then, the controller 30A executes steps S117 and onwards, similarly to the first embodiment.

[0113] Here, the pallet position calculation unit 31 executes steps S101, S102, S109, S110, S126, S127, S120, and S121. The self-position estimation unit 32 executes steps S103, S106, S114, and S117. The route generation unit 33 executes step S104. The guidance control unit 34 executes steps S105 to S108. The approach determination unit 35 executes step S111. The evacuation control unit 41 executes step S125. The re-route generation unit 36A executes step S115A. The re-guiding control unit 37A executes steps S116A to S119. The re-approach determination unit 38 executes step S122. The loading and unloading control unit 39 executes steps S112 and S113. The warning control unit 40 executes step S123.

[0114] In such a loading control device 20A, as shown in Figure 9(a), when the forklift 1 reaches the loading position P, the camera 21 captures an image of the pallet 11A to be unloaded, and as in the first embodiment described above, it is determined whether the forklift 1 has successfully approached the loading position P.

[0115] When the forklift 1 fails to approach the loading position P due to deviation of the forklift 1 from the target pallet 11A, the forklift 1 returns to the start position P0 as shown in FIG. 9(b).

[0116] Then, at the start position P0, the camera 21 captures an image of the target pallet 11A, the position and attitude of the target pallet 11A relative to the forklift 1 are calculated, and a travel route to the loading position P is generated again. Then, as shown in Fig. 9(c), the forklift 1 again approaches the loading position P along the travel route. The subsequent operations are the same as those in the first embodiment described above.

[0117] As described above, in this embodiment, if the forklift 1 fails to approach the loading position P, the forklift 1 is first controlled to retreat to the loading position P. Then, based on the position and posture of the target pallet 11A relative to the forklift 1, the forklift 1 is controlled to approach the loading position P again. This shortens the travel distance of the forklift 1 after a travel route is set for retrying the forklift 1's approach to the loading position P. This further increases the probability that the forklift 1 will reach the appropriate loading position P corresponding to the position of the target pallet 11A.

[0118] In addition, in this embodiment, if the approach of the forklift 1 to the loading position P fails, the forklift 1 is temporarily retreated to the start position P0, which is known in advance as position information, thereby simplifying the processing of the controller 30A.

[0119] Fig. 10 is a block diagram showing the configuration of a cargo handling control device according to a third embodiment of the present invention. In Fig. 10, a cargo handling control device 20B of this embodiment includes a controller 30B instead of the controller 30 in the first embodiment.

[0120] The controller 30B has a pallet position calculation unit 31, a self-position estimation unit 32, a route generation unit 33, a guidance control unit 34, an approach determination unit 35, a detection feasibility determination unit 42, an evacuation control unit 41, a re-route generation unit 36B, a re-guidance control unit 37B, a re-approach determination unit 38, a loading and unloading control unit 39, and an alarm control unit 40.

[0121] The detection feasibility determination unit 42 determines whether the camera 21 can detect the target pallet 11A at the loading position P when the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed.

[0122] When the detection feasibility determination unit 42 determines that the camera 21 cannot detect the target pallet 11A at the loading position P, the evacuation control unit 41 controls the traveling drive unit 24 to temporarily evacuate the forklift 1 to the loading position P. The evacuation control unit 41 controls the traveling drive unit 24 to temporarily evacuate the forklift 1 to the start position P0 from the loading position P.

[0123] When the detection feasibility determination unit 42 determines that the camera 21 can detect the target pallet 11A at the loading position P, the re-route generation unit 36B re-generates a travel route to the loading position P based on the position and attitude of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculation unit 31 at the loading position P and the self-position of the forklift 1 estimated by the self-position estimation unit 32. At this time, the re-route generation unit 36B generates a travel route to the loading position P such that the forklift 1 moves backward once from the loading position P and then moves forward toward the loading position P (see FIG. 6).

[0124] When the detection feasibility determination unit 42 determines that the camera 21 cannot detect the target pallet 11A at the loading position P, the re-route generation unit 36B re-generates a travel route to the loading position P based on the position and attitude of the target pallet 11A relative to the forklift 1 calculated by the pallet position calculation unit 31 at the start position P0 and the self-position of the forklift 1 estimated by the self-position estimation unit 32. At this time, the re-route generation unit 36B generates a travel route that moves the forklift 1 forward toward the loading position P (see FIG. 12).

[0125] The re-guiding control unit 37B controls the traveling drive unit 24 to re-guide the forklift 1 to the loading position P according to the traveling route generated by the re-route generating unit 36B based on the self-position of the forklift 1 estimated by the self-position estimating unit 32.

[0126] The re-guiding control unit 37B works in cooperation with the self-position estimation unit 32, the evacuation control unit 41 and the re-route generation unit 36B to constitute a re-approach control unit that controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be unloaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed.

[0127] When the detection feasibility determination unit 42 determines that the camera 21 is capable of detecting the pallet 11A to be loaded at the loading position P, the re-approach control unit controls the forklift 1 to temporarily retreat from the loading position P and then re-approach the loading position P based on the position of the pallet 11A to be loaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 is at the loading position P.

[0128] When the detection feasibility determination unit 42 determines that the camera 21 cannot detect the pallet 11A to be loaded at the loading position P, the re-approach control unit controls the forklift 1 to temporarily retreat to the start position P0 relative to the loading position P, and then controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be loaded relative to the forklift 1 calculated by the pallet position calculation unit 31.

[0129] Fig. 11 is a flowchart showing the procedure of the cargo handling control process executed by the controller 30B, and corresponds to Fig. 4 and Fig. 8. In Fig. 11, the controller 30B executes steps S101 to S111 in the same manner as in the first and second embodiments.

[0130] When the controller 30B determines in step S111 that the approach of the forklift 1 to the loading position P has failed, it determines whether the camera 21 can detect the pallet 11A to be loaded at the loading position P based on the position and attitude of the pallet 11A to be loaded relative to the forklift 1 calculated in step S110 (step S129).

[0131] At this time, if the pallet 11A to be removed is within the angle of view θ of the camera 21 (see FIG. 9(a)), the camera 21 can detect the pallet 11A to be removed. If the pallet 11A to be removed is outside the angle of view θ of the camera 21 (see FIG. 12(a)), the camera 21 cannot detect the pallet 11A to be removed.

[0132] When the controller 30B determines that the camera 21 can detect the target pallet 11A at the loading position P, it executes step S114 in the same manner as in the first embodiment.

[0133] When the controller 30B determines that the camera 21 cannot detect the target pallet 11A at the loading position P, it executes steps S125 to S127 and S114 in the same manner as in the second embodiment.

[0134] After executing step S114, the controller 30B again generates a travel route from the current position of the forklift 1 to the loading position P (step S115B). Next, the controller 30B controls the traveling drive unit 24 so as to cause the forklift 1 to approach the loading position P again along the travel route (step S116B). Then, the controller 30B executes steps S117 and onwards, similarly to the first and second embodiments.

[0135] Here, the pallet position calculation unit 31 executes steps S101, S102, S109, S110, S126, S127, S120, and S121. The self-position estimation unit 32 executes steps S103, S106, S114, and S117. The route generation unit 33 executes step S104. The guidance control unit 34 executes steps S105 to S108. The approach determination unit 35 executes step S111. The detection feasibility determination unit 42 executes step S129. The evacuation control unit 41 executes step S125. The re-route generation unit 36B executes step S115B. The re-guiding control unit 37B executes steps S116B to S119. The re-approach determination unit 38 executes step S122. The loading and unloading control unit 39 executes steps S112 and S113. The warning control unit 40 executes step S123.

[0136] In such a cargo handling control device 20B, as shown in Fig. 12(a), when the forklift 1 reaches the loading position P, it is determined whether the forklift 1 has successfully approached the loading position P. If the forklift 1 has failed to approach the loading position P, it is determined whether the camera 21 can detect the target pallet 11A.

[0137] When the target pallet 11A can be detected by the camera 21, similarly to the above-described first embodiment, a travel route to the loading position P is generated again based on the position and posture of the target pallet 11A relative to the forklift 1 at the loading position P. Then, the forklift 1 approaches the loading position P again along the travel route.

[0138] When the camera 21 cannot detect the target pallet 11A, the forklift 1 returns to the start position P0 as shown in FIG. 12(b), in the same manner as in the second embodiment.

[0139] Then, at the start position P0, the camera 21 captures an image of the target pallet 11A, the position and attitude of the target pallet 11A relative to the forklift 1 are detected, and a travel route to the loading position P is generated again. Then, as shown in Fig. 12(c), the forklift 1 again approaches the loading position P along the travel route. The subsequent operations are the same as those in the second embodiment described above.

[0140] As described above, in this embodiment, when the camera 21 can detect the target pallet 11A at the loading position P, the forklift 1 is controlled to retreat to the loading position P and then re-approach the loading position P based on the position of the target pallet 11A relative to the forklift 1 at the loading position P. When the camera 21 cannot detect the target pallet 11A at the loading position P, the forklift 1 is controlled to retreat to the loading position P and then re-approach the loading position P based on the position of the target pallet 11A relative to the forklift 1. In this way, by switching the retry method of the forklift 1's approach to the loading position P depending on whether the camera 21 can detect the target pallet 11A at the loading position P, the forklift 1 can appropriately retry its approach to the loading position P depending on the usage environment.

[0141] In addition, in this embodiment, when it is determined that the camera 21 cannot detect the pallet 11A to be picked up, the forklift 1 is temporarily retreated to the start position P0, which is known in advance as position information, thereby simplifying the processing of the controller 30B.

[0142] Fig. 13 is a block diagram showing the configuration of a cargo handling control device according to a fourth embodiment of the present invention. In Fig. 13, a cargo handling control device 20C of this embodiment includes a side camera 51 and a front camera 52 instead of the camera 21 in the third embodiment.

[0143] The side camera 51 and the front camera 52 are image sensors that capture images of the pallet 11 loaded on the loading platform 18 of the truck 17. The side camera 51 and the front camera 52 constitute an object detection unit that detects the pallet 11A to be unloaded.

[0144] The side camera 51 captures an image within a predetermined angle range including the side of the forklift 1 and outputs image data. The side cameras 51 are disposed on both the left and right sides of the forklift 1. The side cameras 51 are first detection units that detect the target pallet 11A when the forklift 1 faces the side of the target pallet 11A.

[0145] The front camera 52, like the above-mentioned camera 21, captures an image of a predetermined angle range including the front of the forklift 1 and outputs image data. The front camera 52 is a second detection unit that detects the target pallet 11A when the forklift 1 faces the front of the target pallet 11A.

[0146] The cargo handling control device 20C includes a controller 30C instead of the controller 30B in the third embodiment. The controller 30C includes a pallet position calculation unit 31C, a self-position estimation unit 32, a route generation unit 33, a guidance control unit 34, an approach determination unit 35, a detection feasibility determination unit 42C, an evacuation control unit 41, a re-route generation unit 36B, a re-guiding control unit 37B, a re-approach determination unit 38, a cargo handling control unit 39, and an alarm control unit 40.

[0147] The pallet position calculation unit 31C calculates the position and attitude of the target pallet 11A relative to the forklift 1 at the start position P0 based on image data from the side camera 51. The pallet position calculation unit 31C calculates the position and attitude of the target pallet 11A relative to the forklift 1 at the loading position P based on image data from the front camera 52.

[0148] The pallet position calculation unit 31C constitutes a position detection unit that calculates the position of the target pallet 11A relative to the forklift 1 based on the detection data from the side camera 51 when the forklift 1 is at the starting position P0, and calculates the position of the target pallet 11A relative to the forklift 1 based on the detection data from the front camera 52 when the forklift 1 is at the loading position P.

[0149] The detection feasibility determination unit 42C determines whether the front camera 52 can detect the pallet 11A to be unloaded at the loading position P when the approach determination unit 35 determines that the approach of the forklift 1 to the loading position P has failed.

[0150] Fig. 14 is a flowchart showing the procedure of the goods removal control process executed by the controller 30C, and corresponds to Fig. 11. This process is executed when the forklift 1 reaches the start position P0, as shown in Fig. 15(a). When the forklift 1 reaches the start position P0, it faces sideways (side surface) with respect to the goods removal target pallet 11A, and the goods removal target pallet 11A can be recognized by the side camera 51.

[0151] 14, the controller 30C first acquires image data from the side camera 51 (step S101C). Then, the controller 30C calculates the position and attitude of the target pallet 11A based on the image data from the side camera 51 (step S102C). Then, the controller 30C executes steps S103 to S108 in the same manner as in the third embodiment.

[0152] After executing step S108, the controller 30C acquires image data from the front camera 52 (step S109C). Then, the controller 30C calculates the position and attitude of the target pallet 11A based on the image data from the front camera 52 (step S110C). Then, the controller 30C executes step S111, similar to the third embodiment.

[0153] When the controller 30C determines in step S111 that the approach of the forklift 1 to the loading position P has failed, it determines whether the front camera 52 can detect the pallet 11A to be loaded at the loading position P based on the position and attitude of the pallet 11A to be loaded relative to the forklift 1 calculated in step S110C (step S129C).

[0154] When the controller 30C determines that the front camera 52 can detect the target pallet 11A at the loading position P, it executes steps S114 to S119 in the same manner as in the third embodiment.

[0155] When the controller 30C determines that the front camera 52 cannot detect the target pallet 11A at the loading position P, it executes step S125 and then acquires image data from the side camera 51 (step S126C). Then, the controller 30C calculates the position and attitude of the target pallet 11A based on the image data from the side camera 51 (step S127C). Then, the controller 30C executes steps S114 to S119 in the same manner as in the third embodiment.

[0156] After executing step S119, the controller 30C acquires image data from the front camera 52 (step S120C). Then, the controller 30C calculates the position and attitude of the target pallet 11A based on the image data from the front camera 52 (step S121C). Then, the controller 30C executes steps S122 and onward, similar to the third embodiment.

[0157] Here, the pallet position calculation unit 31C executes steps S101C, S102C, S109C, S110C, S126C, S127C, S120C, and S121C. The self-position estimation unit 32 executes steps S103, S106, S114, and S117. The route generation unit 33 executes step S104. The guidance control unit 34 executes steps S105 to S108. The approach determination unit 35 executes step S111. The detection feasibility determination unit 42C executes step S129C. The evacuation control unit 41 executes step S125. The re-route generation unit 36B executes step S115B. The re-guiding control unit 37B executes steps S116B to S119. The re-approach determination unit 38 executes step S122. The cargo handling control section 39 executes steps S112 and S113. The warning control section 40 executes step S123.

[0158] In such a cargo handling control device 20C, as shown in Fig. 15(a), the forklift 1 travels straight along one side (here, the right side) of the truck 17 in the front-rear direction of the truck 17. Then, when the forklift 1 reaches a start position P0 where it is oriented sideways with respect to the target pallet 11A, the forklift 1 stops traveling.

[0159] In this state, the pallet 11A to be removed is imaged by the side camera 51. Then, based on the image data from the side camera 51, the position and attitude of the pallet 11A to be removed relative to the forklift 1 are calculated, and a travel route D to the loading position P corresponding to the position of the pallet 11A to be removed is generated. At this time, as shown in Fig. 15(b), the travel route D is generated such that the forklift 1 moves backwards straight for a certain distance and then moves forward while turning right toward the loading position P. Then, the forklift 1 approaches the loading position P along the travel route D.

[0160] 15(c), when the forklift 1 reaches the loading position P, the image of the target pallet 11A is captured by the front camera 52. Then, based on the image data of the front camera 52, the position and attitude of the target pallet 11A relative to the forklift 1 are calculated, and it is determined whether the forklift 1 has successfully approached the loading position P.

[0161] If the forklift 1 fails to approach the loading position P, and the target pallet 11A can be detected by the front camera 52 as shown in Fig. 16(a), a travel route to the loading position P is generated again. At this time, as shown in Fig. 16(b), a travel route is generated in which the forklift 1 retreats while turning right once toward the loading position P, and then advances while turning right again toward the loading position P. Then, the forklift 1 approaches the loading position P again along the travel route as shown in Fig. 16(c).

[0162] If the forklift 1 fails to approach the loading position P and the target pallet 11A cannot be detected by the front camera 52 as shown in Fig. 17(a), the forklift 1 returns to the start position P0. At this time, the forklift 1 reaches the start position P0 by turning right with respect to the loading position P while retreating and then moving forward as shown in Fig. 17(b).

[0163] The target pallet 11A is then imaged again by the side camera 51. The position and attitude of the target pallet 11A relative to the forklift 1 are calculated based on the image data from the side camera 51, and a travel route to the loading position P is generated again. The forklift 1 then approaches the loading position P again along the travel route, as shown in FIG. 17(c).

[0164] As described above, in this embodiment, when the forklift 1 is at the start position P0, the side camera 51 detects the target pallet 11A while the forklift 1 faces sideways toward the target pallet 11A. Then, the forklift 1 is controlled to approach the loading position P. Therefore, even if the space in front of the target pallet 11A is narrow, the forklift 1 can be driven to the loading position P corresponding to the position of the target pallet 11A to perform loading.

[0165] In this embodiment, processing corresponding to the controller 30B in the above-described third embodiment is executed, but processing corresponding to the controller 30 in the above-described first embodiment or the controller 30A in the above-described second embodiment may also be executed.

[0166] Fig. 18 is a block diagram showing the configuration of a cargo handling control device according to a fifth embodiment of the present invention. In Fig. 18, a cargo handling control device 20D of this embodiment includes a controller 30D instead of the controller 30 in the first embodiment.

[0167] The controller 30B has a pallet position calculation unit 31, a self-position estimation unit 32, a route generation unit 33, a guidance control unit 34, an approach determination unit 35D, a cargo pickup feasibility determination unit 45, a re-route generation unit 36D, a re-guidance control unit 37D, a re-approach determination unit 38D, a re-approach count determination unit 46, a loading and unloading control unit 39D, an abnormal stop control unit 47, and an alarm control unit 40.

[0168] The approach determination unit 35D determines whether the approach of the forklift 1 to the loading position P is successful based on the position and posture of the pallet 11A to be loaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 reaches the loading position P.

[0169] The approach determination unit 35D determines whether the following conditions are satisfied: a first condition that the roll angle of the forklift 1 relative to the pallet 11A to be loaded is equal to or less than a predetermined first specified angle; a second condition that the pitch angle of the forklift 1 relative to the pallet 11A to be loaded is equal to or less than a predetermined second specified angle; a third condition that the lateral deviation amount of the forklift 1 relative to the pallet 11A to be loaded is equal to or less than a predetermined specified amount; and a fourth condition that the yaw angle of the forklift 1 relative to the pallet 11A to be loaded is equal to or less than a predetermined third specified angle.

[0170] When the first condition, the second condition, the third condition, and the fourth condition are all satisfied, the approach determination unit 35D determines that the approach of the forklift 1 to the loading position P is successful. When any of the first condition, the second condition, the third condition, and the fourth condition is not satisfied, the approach determination unit 35D determines that the approach of the forklift 1 to the loading position P is unsuccessful.

[0171] When the approach determination unit 35D determines that the approach of the forklift 1 to the loading position P has failed, the loading feasibility determination unit 45 determines whether there is a possibility that the forklift 1 will be able to successfully load the pallet 11A to be loaded by re-approaching the loading position P, based on the position and posture of the pallet 11A to be loaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 reaches the loading position P.

[0172] When the above first condition and second condition are satisfied, the pickup feasibility determination unit 45 determines that there is a possibility that the pickup of the target pallet 11A can be successful by the forklift 1 re-approaching the loading position P. When either the above first condition or second condition is not satisfied, the pickup feasibility determination unit 45 determines that there is no possibility that the pickup of the target pallet 11A can be successful even if the forklift 1 re-approaches the loading position P.

[0173] When the unloading feasibility determination unit 45 determines that there is a possibility that the forklift 1 will be able to successfully unload the pallet 11A to be unloaded by re-approaching the loading position P, the re-route generation unit 36D regenerates a driving route to the loading position P based on the position and attitude of the pallet 11A to be unloaded relative to the forklift 1 at the loading position P calculated by the pallet position calculation unit 31 and the self-position of the forklift 1 estimated by the self-position estimation unit 32.

[0174] The re-guiding control unit 37D controls the traveling drive unit 24 to re-guide the forklift 1 to the loading position P according to the traveling route regenerated by the re-route generating unit 36D based on the self-position of the forklift 1 estimated by the self-position estimating unit 32.

[0175] The re-guiding control unit 37D, in cooperation with the self-position estimation unit 32 and the re-route generation unit 36D, constitutes a re-approach control unit that controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be loaded relative to the forklift 1 calculated by the position calculation unit when the loading feasibility determination unit 45 determines that there is a possibility that the loading of the target pallet 11A can be successfully performed by the forklift 1 re-approaching the loading position P.

[0176] If the re-approach determination unit 38D described later determines that the forklift 1's re-approach to the loading position P has failed, the re-approach control unit controls the forklift 1 to re-approach the loading position P based on the position of the pallet 11A to be unloaded relative to the forklift 1 calculated by the position calculation unit.

[0177] The re-approach determination unit 38D determines whether the forklift 1 has successfully re-approached the loading position P based on the position and posture of the pallet 11A to be unloaded relative to the forklift 1 calculated by the pallet position calculation unit 31 when the forklift 1 reaches the loading position P again.

[0178] When the re-approach determination unit 38D determines that the re-approach of the forklift 1 to the loading position P has failed, the re-approach count determination unit 46 determines whether the number of re-approaches of the forklift 1 to the loading position P has reached a predetermined upper limit value.

[0179] When the approach determination unit 35D determines that the forklift 1 has successfully approached the loading position P, the cargo handling control unit 39D controls the lift drive unit 25, the reach drive unit 26, and the side shift drive unit 27 to load the target pallet 11A. When the re-approach determination unit 38D determines that the forklift 1 has successfully re-approached the loading position P, the cargo handling control unit 39D controls the lift drive unit 25, the reach drive unit 26, and the side shift drive unit 27 to load the target pallet 11A.

[0180] The abnormal stop control unit 47 controls the traveling drive unit 24 to abnormally stop the traveling of the forklift 1 when the unloading feasibility determination unit 45 determines that there is no possibility of successful unloading of the target pallet 11A even if the forklift 1 re-approaches the loading position P. In addition, the abnormal stop control unit 47 controls the traveling drive unit 24 to abnormally stop the traveling of the forklift 1 when the re-approach count determination unit 46 determines that the number of re-approaches of the forklift 1 to the loading position P has reached an upper limit.

[0181] FIG. 19 is a flowchart showing the procedure of the cargo unloading control process executed by the controller 30D, and corresponds to FIG.

[0182] 19, the controller 30D executes steps S101 to S111 in the same manner as in the first embodiment. When the controller 30D determines in step S111 that the forklift 1 has successfully approached the loading position P, it executes steps S112 and S113.

[0183] When the controller 30D determines in step S111 that the forklift 1 has failed to approach the loading position P, it determines, based on the position and attitude of the pallet 11A to be loaded relative to the forklift 1 calculated in step S110, whether there is a possibility that the forklift 1 will be able to successfully load the pallet 11A to be loaded by re-approaching the loading position P (step S131).

[0184] Here, patterns in which the loading of the target pallet 11A fails include a pattern in which the success rate of the loading increases by re-approaching (retrying) the forklift 1 to the loading position P, and a pattern in which the success rate of the loading does not increase even if the forklift 1 re-approaches the loading position P.

[0185] 20(a), a pattern in which the success rate of loading is increased by retrying the forklift 1's approach occurs due to a self-location estimation error or a guidance error of the forklift 1, and the forklift 1 is not in a position or posture that allows loading from the target pallet 11A, as shown in FIG. 20(a). Examples of such a state include a state in which the lateral deviation (deviation in the Y-axis direction) of the forklift 1 relative to the target pallet 11A is large, and a state in which the yaw angle (tilt angle around the Z-axis) of the forklift 1 relative to the target pallet 11A is large.

[0186] On the other hand, a pattern in which the success rate of pickup does not increase even if the forklift 1 retry the approach is a state in which the loading platform 18 of the truck 17 or the target pallet 11A itself is tilted, as shown in Fig. 20(b), so that the forklift 1 fails to pick up the target pallet 11A even if it moves along the ideal path and reaches the front of the target pallet 11A, as shown in Fig. 20(b). Examples of such a state include a state in which the roll angle (tilt angle around the X-axis) of the forklift 1 with respect to the target pallet 11A is large, and a state in which the pitch angle (tilt angle around the Y-axis) of the forklift 1 with respect to the target pallet 11A is large.

[0187] The amount of deviation in the X-axis direction of the forklift 1 from the target pallet 11A can be accommodated by changing the front-to-rear position of the forks 12 with the reach cylinder 14, or by moving the forklift 1 forward or backward to change the front-to-rear position of the forks 12. The amount of deviation in the Z-axis direction of the forklift 1 from the target pallet 11A can be accommodated by changing the height position of the forks 12 with the lift cylinder 13.

[0188] FIG. 21 is a flowchart showing the details of steps S111 and S131 shown in FIG.

[0189] 21, the controller 30D first determines whether the roll angle of the forklift 1 relative to the target pallet 11A is equal to or smaller than a first specified angle θx based on the attitude of the target pallet 11A relative to the forklift 1 obtained in step S110 (step S161). In other words, the controller 30D determines whether the roll angle of the forklift 1 relative to the target pallet 11A satisfies a first condition that the roll angle is equal to or smaller than a first specified angle θx.

[0190] The first specified angle θx is an angle at which the forks 12 can be inserted into the fork holes 11a of the target pallet 11A when the forklift 1 is tilted about the X-axis with respect to the target pallet 11A (see FIG. 22(b)).

[0191] Specifically, as shown in FIG. 23, if the width of the forks 12 is Fw, the distance between the centers of the two forks 12 is Fd, the thickness of the forks 12 is Fh, and the height of the fork holes 11a of the target pallet 11A is Ph, when the roll angle of the forklift 1 relative to the target pallet 11A, as expressed by the following formula, is greater than the first specified angle θx, the forks 12 cannot be inserted into the fork holes 11a of the target pallet 11A.

[0192]

number

[0193] The second specified angle θy is an angle at which the forks 12 inserted into the fork holes 11a of the pallet 11A to be loaded do not interfere with the inner wall surface of the pallet 11A to be loaded when the forklift 1 is tilted around the Y axis relative to the pallet 11A to be loaded (see Figure 22 (c)).

[0194] Specifically, as shown in Figure 23, if the thickness of the forks 12 is Fh, the height of the fork holes 11a of the pallet 11A to be loaded is Ph, and the depth length of the fork holes 11a is Pd, when the pitch angle of the forklift 1 relative to the pallet 11A to be loaded, expressed by the following formula, is greater than the second specified angle θy, the forks 12 inserted into the fork holes 11a of the pallet 11A to be loaded will interfere with the inner wall surface of the pallet 11A to be loaded.

[0195]

number

[0196] The specified amount J is a value that does not exceed the maximum side shift amount of the forks 12 by the side shift cylinders 15. If the center position of the target pallet 11A exceeds the maximum side shift amount of the forks 12 by the side shift cylinders 15, the lateral displacement amount of the forks 12 relative to the target pallet 11A becomes larger than the specified amount J (see FIG. 22(a)).

[0197] When the controller 30D determines that the lateral deviation of the forks 12 relative to the target pallet 11A is equal to or less than the specified amount J, it determines whether or not the yaw angle of the forks 12 relative to the target pallet 11A is equal to or less than a predetermined third specified angle θz based on the attitude of the target pallet 11A relative to the forklift 1 (step S164). In other words, the controller 30D determines whether or not the fourth condition that the yaw angle of the forklift 1 relative to the target pallet 11A is equal to or less than the predetermined third specified angle θz is satisfied.

[0198] The third specified angle θz is an angle at which the forks 12 inserted into the fork holes 11a of the pallet 11A to be loaded do not interfere with the inner wall surface of the pallet 11A to be loaded when the forklift 1 is tilted around the Z axis relative to the pallet 11A to be loaded (see Figure 22 (d)).

[0199] Specifically, as shown in Figure 23, if the width of the fork 12 is Fw, the width of the fork hole 11a of the pallet 11A to be loaded is Pw, and the depth length of the fork hole 11a is Pd, when the yaw angle of the forklift 1 relative to the pallet 11A to be loaded, expressed by the following formula, is greater than the third specified angle θz, the fork 12 inserted into the fork hole 11a of the pallet 11A to be loaded will interfere with the inner wall surface of the pallet 11A to be loaded.

[0200]

number

[0201] When the controller 30D determines in step S163 that the amount of lateral deviation of the forks 12 relative to the pallet 11A to be loaded is greater than the specified amount J, or when the controller 30D determines in step S164 that the yaw angle of the forks 12 relative to the pallet 11A to be loaded is greater than the third specified angle θz, it determines that the approach of the forklift 1 to the loading position P has failed (step S166).

[0202] Then, the controller 30D determines that there is a possibility that the forklift 1 will be able to successfully pick up the object pallet 11A by retrying to approach the loading position P again (step S167). Then, the controller 30D executes step S114 in FIG.

[0203] When the controller 30D determines in step S161 that the roll angle of the forklift 1 relative to the pallet 11A to be loaded is greater than the first specified angle θx, or when the controller 30D determines in step S162 that the pitch angle of the forklift 1 relative to the pallet 11A to be loaded is greater than the second specified angle θy, it determines that the approach of the forklift 1 to the loading position P has failed (step S168).

[0204] Then, the controller 30D determines that there is no possibility of successful pickup of the pickup target pallet 11A even if the forklift 1 re-approaches (retry) the loading position P (step S169). Then, the controller 30D executes step S132 (described later) in FIG. 19.

[0205] Here, step S111 in Fig. 19 corresponds to steps S161 to S166 and S168. Step S131 in Fig. 19 corresponds to steps S161 to S164, S167 and S169.

[0206] 19, when the controller 30D determines in step S131 that there is a possibility that the forklift 1 will be able to successfully pick up the target pallet 11A by re-approaching the loading position P, the controller 30D executes steps S114 to S122. Details of step S122 are the same as those of step S111 described above.

[0207] When the controller 30D determines in step S131 that there is no possibility of the forklift 1 successfully picking up the target pallet 11A even if the forklift 1 approaches the loading position P again, the controller 30D controls the traveling drive unit 24 to abnormally stop the traveling of the forklift 1 (step S132). Then, the controller 30D executes step S123.

[0208] When the controller 30D determines in step S122 that the re-approach of the forklift 1 to the loading position P has failed, it determines whether the number of re-approaches (number of retries) of the forklift 1 to the loading position P has reached a predetermined upper limit (step S133). The upper limit may be one time, as in the first embodiment, or may be multiple times. When the controller 30D determines that the number of re-approaches of the forklift 1 to the loading position P has not reached the upper limit, it executes the above step S114 again.

[0209] When the controller 30D determines that the number of re-approaches of the forklift 1 to the loading position P has reached the upper limit, the controller 30D controls the traveling drive unit 24 to abnormally stop the traveling of the forklift 1 (step S132). Then, the controller 30D executes step S123.

[0210] Here, the pallet position calculation unit 31 executes steps S101, S102, S109, S110, S120, and S121. The self-position estimation unit 32 executes steps S103, S106, S114, and S117. The route generation unit 33 executes step S104. The guidance control unit 34 executes steps S105 to S108. The approach determination unit 35D executes step S111. The cargo pickup feasibility determination unit 45 executes step S131. The re-route generation unit 36D executes step S115. The re-guiding control unit 37D executes steps S116 to S119. The re-approach determination unit 38D executes step S122. The re-approach count determination unit 46 executes step S133. The cargo handling control unit 39D executes steps S112 and S113. The abnormal stop control unit 47 executes step S132. The warning control unit 40 executes step S123.

[0211] Incidentally, when the success rate of cargo pick-up is increased, the number of times abnormality measures are taken can be reduced and the cargo pick-up cycle time can be shortened by retrying the approach of the forklift 1 to the cargo handling position P. However, when the success rate of cargo pick-up is not increased but the approach of the forklift 1 to the cargo handling position P is retried, the response to the abnormality measures is delayed by the time required for the retry of the approach of the forklift 1 compared to the case where the travel of the forklift 1 is immediately stopped due to the abnormality, resulting in an increase in the cargo pick-up cycle time.

[0212] Therefore, in this embodiment, when it is determined that the approach of the forklift 1 to the loading position P has failed, it is determined whether there is a possibility that the loading of the target pallet 11A will be successful by the forklift 1 approaching the loading position P again. Then, when it is determined that there is no possibility that the loading of the target pallet 11A will be successful even if the forklift 1 approaches the loading position P again, the travel of the forklift 1 is stopped due to an abnormality, so that it is not necessary to retry the approach of the forklift 1, which would be wasteful. Therefore, the total time required for dealing with the abnormality and the loading time are reduced.

[0213] In this embodiment, if the position or posture of the target pallet 11A relative to the forklift 1 deviates by a certain amount or more, it is determined that the approach of the forklift 1 to the loading position P has failed. Therefore, the success or failure of the approach of the forklift 1 to the loading position P is appropriately determined.

[0214] In addition, in this embodiment, for example, if the pallet 11A to be removed is tilted and the roll angle of the forklift 1 relative to the pallet 11A to be removed exceeds the first specified angle θx, or the pitch angle of the forklift 1 relative to the pallet 11A to be removed exceeds the second specified angle θy, there is no need to perform a wasteful retry of the approach of the forklift 1.

[0215] In addition, in this embodiment, if the forklift 1 fails to re-approach the loading position P, the forklift 1 will retry approaching the loading position P, thereby increasing the probability that the forklift 1 will reach the appropriate loading position P corresponding to the position of the pallet 11A to be picked up. This further improves the success rate of loading by the forklift 1.

[0216] In addition, in this embodiment, when the number of retries of the forklift 1 to approach the loading position P reaches an upper limit, the forklift 1 is stopped due to an abnormality, so that the forklift 1 does not need to retry the approach more than necessary. Therefore, the total time required for dealing with the abnormality and the loading / unloading time are further reduced.

[0217] In this embodiment, the process corresponding to the controller 30 in the first embodiment is executed, but the process corresponding to the controllers 30A to 30C in the second to fourth embodiments may be executed.

[0218] Although several embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments. For example, in the second to fourth embodiments, when the approach of the forklift 1 to the loading position P fails, the forklift 1 is temporarily retreated from the loading position P to the start position P0, but the present invention is not limited to this embodiment, and the forklift 1 may be temporarily retreated to a position away from the loading position P.

[0219] In addition, in the above embodiment, unloading is performed from the pallet 11 loaded on the loading platform 18 of the truck 17, but this is not limited to a particular form, and unloading may be performed from the pallet 11 loaded on, for example, a truck berth or a designated floor surface, etc.

[0220] In addition, in the above embodiment, the loading is performed on the pallet 11, but the loading is not limited to loading, and the pallet 11 held by the forks 12 of the forklift 1 may be placed on the loading platform 18 of the truck 17, or the like, in other words, loading may be performed.

[0221] In addition, in the above embodiment, the position and posture of the pallet 11A to be picked up relative to the forklift 1 are calculated based on the image data from the camera 21 or the side camera 51 and the front camera 52, but this is not limited to a particular form, and only the position of the pallet 11A to be picked up relative to the forklift 1 may be calculated.

[0222] In addition, in the above embodiment, the pallet 11A to be loaded is detected by the camera 21 or the side camera 51 and the front camera 52, but the object detection unit for detecting the object to be loaded is not limited to a camera, and a laser sensor, an ultrasonic sensor, an optical sensor, etc. may also be used.

[0223] In the above embodiment, the forklift 1 is a reach forklift, but the forklift 1 may be a counter-loading forklift. In this case, when a load is to be picked up, the forklift 1 is driven forward to insert the forks 12 into the fork holes of the load-receiving target pallet 11A.

[0224] Further, in the above embodiment, the forklift 1 is equipped with the side shift cylinder 15, however, the present invention is also applicable to a forklift that is not equipped with the side shift cylinder 15. [Explanation of symbols]

[0225] 1...Forklift, 11A...Pallet to be picked up (loading object), 12...Fork, 15...Side shift cylinder, 20, 20A, 20B, 20C, 20D...Load handling control device, 21...Camera (object detection unit), 31, 31C...Pallet position calculation unit (position calculation unit), 32...Self-position estimation unit (approach control unit), 33...Route generation unit (approach control unit), 34...Guidance control unit (approach control unit), 35, 35D...Approach determination unit, 36, 36A, 36B, 36D...Re-route generation unit (re-approach control unit), 37, 37A, 37B, 37D...re-guidance control unit (re-approach control unit), 38, 38D...re-approach determination unit, 39, 39D...loading control unit, 40...alarm control unit (notification unit), 41...evacuation control unit (re-approach control unit), 42...detection feasibility determination unit, 45...loading feasibility determination unit, 46...re-approach count determination unit, 47...abnormal stop control unit, 51...side camera (first detection unit, target detection unit), 52...front camera (second detection unit, target detection unit), P0...starting position, P...loading position, J...prescribed amount, θx...first prescribed angle, θy...second prescribed angle, θz...third prescribed angle.

Claims

1. A cargo handling control device that moves a forklift from a start position toward a cargo handling target, An object detection unit that detects the loading object; a position calculation unit that calculates a position of the loading object relative to the forklift based on detection data from the object detection unit; an approach control unit that controls the forklift to approach a loading position corresponding to the loading object based on a position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the start position; an approach determination unit that determines whether the approach of the forklift to the loading position has been successful based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position; a loading control unit that controls the forklift to perform loading on the loading target when the approach determination unit determines that the approach of the forklift to the loading position is successful; A loading and unloading control device comprising: a re-approach control unit that controls the forklift to re-approach the loading and unloading position based on the position of the loading object relative to the forklift calculated by the position calculation unit when the approach determination unit determines that the forklift's approach to the loading and unloading position has failed.

2. 2. The loading control device according to claim 1, wherein, when it is determined that the forklift's approach to the loading position has failed, the re-approach control unit controls the forklift to temporarily retreat from the loading position and then re-approach the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the loading position.

3. 2. The loading control device according to claim 1, wherein, when it is determined that the forklift's approach to the loading position has failed, the re-approach control unit controls the forklift to temporarily retreat from the loading position, and then controls the forklift to re-approach the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit.

4. 4. The loading control device according to claim 3, wherein the re-approach control unit controls the forklift to temporarily retreat to the starting position relative to the loading position, and then controls the forklift to re-approach the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the starting position.

5. a detection feasibility determination unit that determines whether the object detection unit can detect the loading object at the loading position when the approach determination unit determines that the approach of the forklift to the loading position has failed, 2. The loading control device according to claim 1, wherein, when the detection feasibility determination unit determines that the object detection unit is capable of detecting the loading object at the loading position, the re-approach control unit controls the forklift to temporarily retreat to the loading position and then re-approach the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the loading position, and when the detection feasibility determination unit determines that the object detection unit is not capable of detecting the loading object at the loading position, the re-approach control unit controls the forklift to temporarily retreat to the loading position and then re-approach the forklift to the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit.

6. 6. The loading control device as described in claim 5, wherein when it is determined that the object detection unit is unable to detect the loading object, the re-approach control unit controls the forklift to temporarily retreat to the start position relative to the loading position, and then controls the forklift to re-approach the loading position based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the start position.

7. The forklift has a side shift cylinder that moves the forks in the left and right directions of the forklift, 2. The loading control device according to claim 1, wherein the approach determination unit determines whether or not a lateral deviation amount of the forklift relative to the loading object is equal to or less than a predetermined specified amount based on the position of the loading object relative to the forklift calculated by the position calculation unit when the forklift is at the loading position, and determines that the approach of the forklift to the loading position has been successful if the lateral deviation amount of the forklift relative to the loading object is equal to or less than the specified amount, and determines that the approach of the forklift to the loading position has been unsuccessful if the lateral deviation amount of the forklift relative to the loading object is not equal to or less than the specified amount.

8. a re-approach determination unit that determines whether or not the forklift has successfully re-approached the loading position based on the position of the loading target relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position again; a notification unit that issues an abnormality notification when the re-approach determination unit determines that the re-approach of the forklift to the loading position has failed, The loading control device according to claim 1, wherein the loading control unit controls the forklift to perform loading on the loading target when the re-approach determination unit determines that the forklift has successfully re-approached the loading position.

9. The cargo handling control device according to claim 1 , wherein the object detection unit detects the cargo handling object when the forklift is facing the cargo handling object.

10. The object detection unit includes a first detection unit that detects the object when the forklift is facing sideways with respect to the object, and a second detection unit that detects the object when the forklift is facing frontward with respect to the object, 2. The loading control device according to claim 1, wherein the position calculation unit calculates the position of the loading object relative to the forklift based on the detection data of the first detection unit when the forklift is at the starting position, and calculates the position of the loading object relative to the forklift based on the detection data of the second detection unit when the forklift is at the loading position.

11. The loading object is a pallet having a pair of fork holes into which a pair of left and right forks of the forklift are inserted, The position calculation unit calculates a position and an attitude of the pallet relative to the forklift based on the detection data of the object detection unit, the approach control unit controls the forklift to approach a loading position corresponding to the position of the pallet based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift is at the start position, the approach determination unit determines whether the approach of the forklift to the loading position has been successful based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position; the loading / unloading control unit controls the forklift to unload the pallet as the loading / unloading operation when the approach determination unit determines that the approach of the forklift to the loading / unloading position has been successful; 2. The loading control device as described in claim 1, wherein, when the approach determination unit determines that the forklift's approach to the loading position has failed, the re-approach control unit controls the forklift to re-approach the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit.

12. a loading possibility determination unit that, when it is determined by the approach determination unit that the approach of the forklift to the loading position has failed, determines whether or not there is a possibility that the forklift will be able to successfully load the pallet by re-approaching the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position; an abnormality stop control unit that controls the forklift to make an abnormal stop of the travel of the forklift when the object-removal possibility determination unit determines that there is no possibility of successful removal of the object from the pallet even if the forklift re-approaches the loading position, A loading control device as described in claim 11, wherein when the loading feasibility determination unit determines that there is a possibility that the loading of the pallet will be successful by the forklift re-approaching the loading position, the re-approach control unit controls the forklift to re-approach the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit.

13. The forklift has a side shift cylinder that moves the forks in the left and right directions of the forklift, 13. The loading control device according to claim 12, wherein the approach determination unit determines whether a first condition is satisfied, that is, a roll angle of the forklift relative to the pallet is equal to or less than a predetermined first specified angle, a second condition is satisfied, that a pitch angle of the forklift relative to the pallet is equal to or less than a predetermined second specified angle, a third condition is satisfied, that a lateral deviation of the forklift relative to the pallet is equal to or less than a predetermined specified amount, and a fourth condition is satisfied, that a yaw angle of the forklift relative to the pallet is equal to or less than a predetermined third specified angle. When the first condition, the second condition, the third condition, and the fourth condition are all satisfied, the approach determination unit determines that the approach of the forklift to the loading position is successful, and when any of the first condition, the second condition, the third condition, and the fourth condition is not satisfied, the approach determination unit determines that the approach of the forklift to the loading position is unsuccessful.

14. The loading control device of claim 13, wherein the loading feasibility determination unit determines that there is a possibility that the loading of the pallet will be successful if the forklift re-approaches the loading position when the first condition and the second condition are satisfied, and determines that there is no possibility that the loading of the pallet will be successful even if the forklift re-approaches the loading position when either the first condition or the second condition is not satisfied.

15. a re-approach determination unit that determines whether or not the forklift has successfully re-approached the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the forklift reaches the loading position again, the re-approach control unit controls the forklift to re-approach the loading position based on the position and attitude of the pallet relative to the forklift calculated by the position calculation unit when the re-approach determination unit determines that the re-approach of the forklift to the loading position has failed, The cargo handling control device according to claim 11, wherein the cargo handling control unit controls the forklift to unload the pallet when the re-approach determination unit determines that the forklift has successfully re-approached the cargo handling position.

16. a re-approach count determination unit that determines whether or not the number of re-approaches of the forklift to the loading position has reached a predetermined upper limit value when the re-approach determination unit determines that the re-approach of the forklift to the loading position has failed; The loading control device according to claim 15, further comprising an abnormality stop control unit that controls the forklift to abnormally stop traveling of the forklift when the re-approach count determination unit determines that the number of re-approaches of the forklift to the loading position has reached the upper limit value.

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