Cargo handling vehicle and cargo handling program

Abstract

To detect, with a simple configuration, an object in front.SOLUTION: A cargo handling vehicle 20 includes: a vehicle body 10; a fork 12 mounted on the vehicle body 10 and configured to perform cargo handling; a fork base end sensor 29 disposed below the fork 12; and a control unit 27. The control unit 27 detects the presence or absence of an object B in front on the basis of distance information acquired by the fork base end sensor 29. Thereby, the object in front can be suitably detected with a simpler configuration than that in the related art in which the sensor is disposed above the fork.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a cargo handling vehicle and a cargo handling program.

Background Art

[0002] Conventionally, cargo handling vehicles such as automated guided forklifts (AGF) that perform cargo handling work are known. In this type of cargo handling vehicle, surrounding information is acquired by the mounted sensors. For example, in the technology described in Patent Document 1, an object in front is detected by a sensor provided above the fork.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the technology described in Patent Document 1 above, the size of the cargo placed on the fork is restricted by the sensor. In addition, the configuration for supporting the sensor is complicated and the vehicle body tends to be enlarged. The present invention has been made in view of the above circumstances, and an object thereof is to detect an object in front with a simple configuration.

Means for Solving the Problems

[0005] The cargo handling vehicle according to the present invention includes a cargo handling unit mounted on the vehicle body for performing cargo handling, a distance sensor disposed below the cargo handling unit, and a detection unit that detects the presence or absence of an object in front based on the distance information acquired by the distance sensor. and is provided with.

Effects of the Invention

[0006] According to the present invention, an object in front can be detected with a simple configuration.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Modes for Carrying Out the Invention

[0008] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0009] [Configuration of Cargo Handling System] FIG. 1 is a diagram showing the cargo handling vehicle 20 according to the present embodiment, and FIG. 2 is a block diagram showing a schematic control configuration of the cargo handling system 1 including the cargo handling vehicle 20. As shown in these figures, the cargo handling system 1 performs predetermined cargo handling operations (operations such as loading and unloading of goods, transportation, stacking, picking, sorting, and alignment of goods and associated operations) in the work area by the cargo handling vehicle 20. The cargo handling system 1 is a system including, for example, a WMS (Warehouse Management System), a WES (Warehouse Execution System), a WCS (Warehouse Control System), and the like.

[0010] Specifically, the handling system 1 includes at least one handling vehicle 20 and a management server 30.

[0011] The handling vehicle 20 is a vehicle for performing handling operations, such as a forklift that can travel on the road without using rails or the like. The handling vehicle 20 holds a load L or a pallet 70 by a pair of left and right forks (handling parts) 12 provided on the vehicle body 10 and performs various handling operations. The handling vehicle 20 of the present embodiment is an automated guided forklift (AGF) that can operate automatically (unattended) and operates based on an operation command or the like from the management server 30.

[0012] Specifically, the handling vehicle 20 includes a vehicle body drive unit 21, a fork drive unit 28, an operation unit 22, a display unit 23, a communication unit 24, a position measurement device 25, a fork base end sensor 29, a storage unit 26, and a control unit 27.

[0013] The vehicle body drive unit 21 includes a traveling motor and a steering motor (both not shown), which are drive sources for the vehicle body 10 of the handling vehicle 20. The traveling motor drives the drive wheels among the wheels. The steering motor rotates (steers) the steering wheels among the wheels. Each motor is powered by a battery (not shown). Note that the drive source is not limited to a motor and may be an internal combustion engine or the like.

[0014] The fork drive unit 28 is a drive source for operating a pair of forks 12 protruding forward. The fork drive unit 28 of the present embodiment includes an inclination cylinder, a lifting cylinder, and a reach cylinder (all not shown) that tilt, lift, and extend / retract (stretch) a pair of forks 12 with respect to the vehicle body main body 11. These cylinders are piston cylinders driven by hydraulic pressure (for example, oil pressure). The inclination cylinder tilts the lifting body 13 or the mast 14 that supports a pair of forks 12 forward and backward with respect to the vehicle body. The lifting cylinder raises and lowers the lifting body 13 that holds a pair of forks 12 along the mast 14. The reach cylinder extends and retracts (stretches) a pair of forks 12 forward and backward with respect to the vehicle body 10 (substantially perpendicular to the mast 14).

[0015] The operation unit 22 is an operation means for the driver to perform various operations during manned (manual) driving. The operation unit 22 includes, for example, a steering wheel, pedals, levers, various buttons, etc., and outputs an operation signal corresponding to these operation contents to the control unit 27. The display unit 23 is, for example, a liquid crystal display, an organic electro-luminescence display, or other displays, and displays various information based on the display signal input from the control unit 27. Note that the display unit 23 may be a touch panel that also serves as a part of the operation unit 22, or may include a speaker capable of voice display (output). The communication unit 24 is a communication device capable of transmitting and receiving various information to and from the management server 30, other handling vehicles 20, etc.

[0016] The position measurement device 25 measures the position of the handling vehicle 20 itself. The information on the self-position acquired by the position measurement device 25 is transmitted, for example, to the management server 30 and used for position control of the handling vehicle 20 itself. The specific configuration of the position measurement device 25 is not particularly limited, and for example, it may utilize GNSS (Global Navigation Satellite System), SLAM (Simultaneous Localization and Mapping) technology, indoor positioning (indoor mapping) technology, or other technologies.

[0017] The fork base end sensor 29 is an example of the distance sensor according to the present invention. It acquires distance information within the scan area (measurement area) N in front of the vehicle body and outputs the result to the control unit 27. The fork base end sensor 29 of the present embodiment is a two-dimensional distance sensor (for example, two-dimensional LiDAR (Laser Imaging Detection and Ranging)) having a planar scan area that is substantially orthogonal to the vertical direction along the mast 14. The fork base end sensor 29 is normally arranged at substantially the same height as the fork 12 (not particularly limited, for example, the height at which the scan area N is slightly above the upper surface of the fork 12), and is arranged at the base end portion substantially in the center between the two forks 12 (see FIG. 5). Further, the fork base end sensor 29 is supported by the lifting body 13 so as to be movable in the vertical direction along the mast 14. Specifically, it is configured to be movable in the vertical direction with respect to the fork 12 by a moving cylinder 291 fixed to the lifting body 13. The fork base end sensor 29 of the present embodiment is used for detecting a hole portion (fork pocket) 72 into which the fork 12 is inserted in the pallet 70 during unloading, and as will be described later, it is also used for detecting an object on the loading table T during loading.

[0018] The storage unit 26 is a memory composed of, for example, RAM (Random Access Memory), ROM (Read Only Memory), etc., stores various programs and data, and also functions as a working area for the control unit 27. The storage unit 26 of the present embodiment stores a program for executing the loading process (see FIG. 3) described later.

[0019] The control unit 27 is composed of, for example, a CPU (Central Processing Unit), etc., and controls the operations of each part of the material handling vehicle 20. Specifically, the control unit 27 operates each part based on a control command from the management server 30 or the operation content of the operation unit 22, develops a program stored in advance in the storage unit 26, and executes various processes in cooperation with the developed program.

[0020] The management server 30 centrally controls the material handling system 1 and is configured to be able to control the operation of the material handling vehicle 20. The management server 30 may be a personal computer, a smartphone, a tablet terminal, etc. Specifically, the management server 30 includes an operation unit 31, a display unit 32, a communication unit 34, a storage unit 36, and a control unit 37.

[0021] The operation unit 31 is an operation means for an operator to perform various operations for operating the management server 30, and includes, for example, a pointing device such as a mouse or a keyboard. The display unit 32 is, for example, a liquid crystal display, an organic electroluminescence display, or other display. The display unit 32 displays various information based on the display signal input from the control unit 37. Further, the display unit 32 may be a touch panel that also serves as at least a part of the operation unit 31. The communication unit 34 is a communication device capable of transmitting and receiving various information to and from each handling vehicle 20.

[0022] The storage unit 36 is a memory constituted by, for example, a RAM (Random Access Memory), a ROM (Read Only Memory), etc., stores various programs and data, and also functions as a work area for the control unit 37. The control unit 37 is constituted by, for example, a CPU (Central Processing Unit), etc., and controls the operations of each part of the management server 30. Specifically, the control unit 37 develops a program prestored in the storage unit 36 based on the operation content of the operation unit 31, etc., and executes various processes in cooperation with the developed program.

[0023] [Loading and unloading process] Subsequently, a loading and unloading (unloading) process for placing the load L held by the handling vehicle 20 will be described. FIG. 3 is a flowchart showing the flow of the loading and unloading process. FIGS. 4 to 6 are diagrams for explaining the loading and unloading process.

[0024] The loading and unloading process is a process executed when the handling vehicle 20 places the load L (pallet 70) at a predetermined loading and unloading location. This loading and unloading process is executed by the control unit 27 of the handling vehicle 20 reading out and developing the corresponding program from the storage unit 26. The program may be a part of a handling program executed for a predetermined handling operation. Here, it is assumed that a loading and unloading operation of placing the load L (pallet 70) held by the fork 12 on the loading and unloading table T is executed. Note that the handling vehicle 20, the fork 12, and the loading and unloading table T are all substantially horizontal.

[0025] As shown in FIG. 3, first, the control unit 27 picks up the load L (pallet 70) at a predetermined location based on a command from the management server 30 (step S1). The management server 30, for example, specifies specific coordinates for the handling vehicle 20 and causes the loading and unloading to be performed at that position. As a result, the handling vehicle 20 holds the load L (pallet 70) with the forks 12 inserted into the hole 72. At the time of this loading and unloading, the hole 72 of the pallet 70 is preferably detected by the fork base end sensor 29.

[0026] Next, the control unit 27 drives (moves) the handling vehicle 20 to before the loading platform T (step S2; FIG. 4(a)). The position where the load L is to be placed is instructed by the management server 30. The loading platform T is not particularly limited as long as it is a place where the load L (pallet 70) can be placed on the upper surface, and may be, for example, a storage shelf in a warehouse or a loading platform of a truck.

[0027] Next, the control unit 27 raises (lifts up) the forks 12 by a predetermined height above the upper surface of the loading platform T and detects an object on the loading platform T with the fork base end sensor 29 (step S3; FIGS. 4(b) and 5). Specifically, first, the control unit 27 lowers the fork base end sensor 29 by the movement cylinder 291 while raising the forks 12, and moves the fork base end sensor 29 below the forks 12 and the pallet 70. At this time, as long as the fork base end sensor 29 can protrude below the pallet 70 before reaching the height of the upper surface of the loading platform T without contacting the floor surface, the relative position (height) relationship with the forks 12 is not particularly limited. Then, the control unit 27 raises the fork 12 until the fork base end sensor 29 reaches above the upper surface of the loading table T. At this time, while raising the fork 12, the control unit 27 scans the front with the fork base end sensor 29. Here, at least the entire range on the upper surface of the loading table T where the pallet 70 is placed is scanned. As a result, the distance information (for example, point cloud data) on the loading table T included in the scan area N of the fork base end sensor 29 is acquired, and if there is an object B on the loading table T, it is detected. In addition, when the height of the loading table T is known (previously input), after exposing the fork base end sensor 29 from the fork 12 at the height, the fork base end sensor 29 may perform a scan.

[0028] Next, the control unit 27 determines whether an object B is detected on the loading table T in step S3 (step S4).

[0029] In step S4, if it is determined in step S3 that no object B is detected on the loading table T (step S4; No), the control unit 27 places the load L on the loading table T (step S5). Specifically, the control unit 27 raises the fork base end sensor 29 by the moving cylinder 291 and returns it to the same height as the fork 12, and at the same time, lowers the fork 12 until the pallet 70 is slightly higher than the loading table T (Fig. 6(a)). Then, the control unit 27 moves the vehicle body 10 and the fork 12 forward to position the pallet 70 above the loading table T, and then lowers the fork 12 to place the pallet 70 (load L) on the loading table T (Fig. 6(b)). After that, the control unit 27 moves the vehicle body 10 backward, removes the fork 12 from the hole 72 of the pallet 70, and then proceeds to step S7 described later.

[0030] On the other hand, in step S4, if it is determined in step S3 that an object B is detected on the loading table T (step S4; Yes), the control unit 27 performs a warning output to warn that there is an obstacle on the loading table T (step S6). Here, after stopping the vehicle body 10, the control unit 27 causes the display unit 23 to display a warning or outputs a warning sound to notify the surrounding workers and the management server 30 that there is an obstacle on the loading platform T. The output (notification) mode in this case is not particularly limited, and for example, a rotating light may be lit. At this time, after temporarily stopping the vehicle body 10 and performing a warning output, the control unit 27 waits for the operator (human) to take action. When the obstacle (object B) is removed by the operator, the temporary stop is manually released by the operator, and the loading and unloading work continues.

[0031] Next, the control unit 27 determines whether to end the loading process (step S7). If it is determined not to end (step S7; No), the process proceeds to step S1 described above to pick up the next load to be transported. On the other hand, for example, if it is determined to end the loading process due to reasons such as completion of a predetermined loading and unloading operation (step S7; Yes), the control unit 27 ends the loading process.

[0032] [Technical effects of this embodiment] As described above, according to this embodiment, the fork base end sensor (distance sensor) 29 is disposed below the fork 12 that performs the loading and unloading, and the presence or absence of an object in front is detected based on the distance information acquired by the fork base end sensor 29. Thereby, with a simpler configuration than in the prior art where the sensor was disposed above the fork, it is possible to detect an object in front without the scan area N being blocked by the fork 12 or the load L. As a result, problems during loading (unloading) such as double storage can be preferably prevented.

[0033] Also, according to this embodiment, the fork base end sensor 29 is supported by the vehicle body 10 so as to be movable in the vertical direction. The fork base end sensor 29 is normally located at the same height as the fork 12, and when loading the load held by the fork 12 onto the front loading platform T, it moves below the fork 12 to acquire the distance information on the loading platform T. As a result, the state in which the fork base end sensor 29 is exposed downward from the fork 12 can be minimized. Therefore, it is possible to suppress a situation in which the fork base end sensor 29 is damaged by contacting the floor surface or the like.

[0034] Further, according to the present embodiment, when the pallet 70 is held by the fork 12 and unloaded, the hole portion 72 of the pallet 70 is detected (detected) based on the distance information acquired by the fork base end sensor 29. That is, the sensor that detects the front object B during loading can also be used as the sensor that detects the hole portion 72 of the pallet 70 during unloading.

[0035] [Others] As described above, the embodiments of the present invention have been described, but the present invention is not limited to the above embodiments (including modified examples).

[0036] For example, in the above embodiment, as an example of the distance sensor according to the present invention, the fork base end sensor 29 mounted on the base end portion of the fork 12 is illustrated. However, the type of the sensor and the like of the distance sensor according to the present invention are not particularly limited as long as it is mounted on the vehicle body 10 and can acquire the distance information in front. Further, the structure (mechanism) for raising and lowering the fork base end sensor 29 in the vertical direction is not particularly limited and is not limited to that by the moving cylinder 291. Furthermore, if the fork base end sensor 29 is disposed below the fork 12, it does not necessarily have to be able to move up and down.

[0037] Also, in the above embodiment, the control unit 27 mounted on the material handling vehicle 20 performs various calculations and the like. However, a control means (for example, a management server 30) provided outside the material handling vehicle 20 may perform calculations based on the information transmitted from the material handling vehicle 20 and transmit the results to the material handling vehicle 20. Further, the material handling vehicle 20 and the management server 30 may cooperate in other modes to perform various controls.

[0038] In the above embodiment, the material handling vehicle 20 is an unmanned vehicle (unmanned forklift) that can operate without a driver. However, the material handling vehicle according to the present invention includes those that can be manned (including remote operation) and those that can switch between manned operation and unmanned operation. Further, the present invention can also be used as an assist function for manned operation. Moreover, the material handling vehicle according to the present invention is not limited to a forklift as long as it can hold a load with a fork (or something similar) and travel, and includes, for example, an automated guided vehicle (AGV) that travels without a driver. In addition, the details shown in the above embodiment can be appropriately changed without departing from the gist of the invention.

Explanation of Reference Numerals

[0039] 1 Material handling system 10 Vehicle body 12 Fork (material handling part) 13 Lifting body 14 Mast 20 Material handling vehicle 26 Storage unit 27 Control unit (detection unit) 29 Fork base end sensor (distance sensor) 291 Moving cylinder 30 Management server 70 Pallet 72 Hole part B Object L Load N Scan area T Loading platform

Claims

1. A cargo handling unit mounted on a vehicle body for performing cargo handling, A distance sensor disposed below the cargo handling unit, A detection unit that detects the presence or absence of an object in front based on the distance information acquired by the distance sensor, A cargo handling vehicle comprising the above.

2. The distance sensor is supported by the vehicle body so as to be movable in the vertical direction, The cargo handling vehicle according to Claim 1.

3. The distance sensor, Normally located at the same height as the cargo handling unit, When placing the load held by the cargo handling unit at a forward storage location, it moves below the cargo handling unit to acquire the distance information of the storage location, The cargo handling vehicle according to Claim 2.

4. When the detection unit inserts the cargo handling unit into a hole of a cargo handling platform and holds the cargo handling platform, the detection unit detects the hole based on the distance information acquired by the distance sensor, The cargo handling vehicle according to Claim 3.

5. The cargo handling vehicle is an unmanned vehicle capable of operating without a driver, The cargo handling vehicle according to Claim 1.

6. A computer of a cargo handling vehicle comprising a vehicle body, a cargo handling unit mounted on the vehicle body for performing cargo handling, and a distance sensor disposed below the cargo handling unit, A detection unit that detects the presence or absence of an object in front based on the distance information acquired by the distance sensor, A cargo handling program that functions as such.

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