Cargo handling vehicle, loading control method, and loading control program

Abstract

To favorably perform loading with a simple configuration.SOLUTION: A forklift 1 includes a movable vehicle body 10, a fork 12 which is provided on the vehicle body 10 to be raised / lowered and can hold a load L, and a control unit 27. The control unit 27 raises the fork 12 up to a height exceeding a maximum height of an expected height of a loading platform 41 when the load L held by the fork 12 is loaded on the loading platform 41, makes the fork 12 approach the loading platform 41 until the load L on the fork 12 is positioned above the loading platform 41, and then lowers the fork 12 until the load L is placed on the loading platform 41.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a cargo handling vehicle, a loading control method, and a loading control program. [Background technology]

[0002] BACKGROUND ART In recent years, unmanned (automatic) operation vehicles such as unmanned forklifts have become widespread as cargo handling vehicles for cargo handling work. When loading cargo onto the bed of a truck using such a cargo handling vehicle, methods are used in which truck information including the height of the bed is obtained in advance from a management system, or the height of the truck bed is detected in advance using marker recognition or a laser sensor, etc. (see, for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-165897 [Patent Document 2] Japanese Patent Application Publication No. 2020-189719 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the conventional methods described above require coordination with a management system that stores truck information, and require sensors to detect the height of the loading platform, which makes the configuration complicated and leads to higher implementation costs. The present invention has been made in view of the above circumstances, and has as its object to provide a simple configuration for suitable loading. [Means for solving the problem]

[0005] The cargo handling vehicle according to the present invention comprises: A drivable vehicle body, a fork that is provided on the vehicle body so as to be able to rise and fall and that can hold a load; a storage unit that stores in advance the height of a platform onto which the load is to be loaded by the forks; a control means; Equipped with the storage unit stores in advance a maximum height among a plurality of possible heights of the mounting table based on a user input when the plurality of possible heights of the mounting table exist; The control means When loading the load held by the forks onto the platform, the platform is not detected, The data stored in the storage unit first means for raising the forks to a height above a maximum height; a second means for moving the forks toward the platform until the load on the forks is positioned on the platform; a third means for lowering the forks until the load is placed on the platform; Includes:

[0006] The present invention provides A method for controlling loading of a cargo handling vehicle including a travelable vehicle body and a fork that is provided on the vehicle body in a manner that allows it to be raised and lowered and that can hold a load, comprising: The cargo handling vehicle includes a storage unit that stores in advance the height of a platform onto which the cargo is loaded by the forks, the storage unit stores in advance a maximum height among a plurality of possible heights of the mounting table based on a user input when the plurality of possible heights of the mounting table exist; The control means When loading the load held by the forks onto the platform, the platform is not detected, The data stored in the storage unit a first step of raising the forks to a height exceeding a maximum height; a second step of moving the forks toward the platform until the load on the forks is positioned on the platform; a third step of lowering the forks until the load is placed on the platform; Execute.

[0007] The present invention provides A loading control program for a cargo handling vehicle including a travelable vehicle body and a fork that is provided on the vehicle body in a liftable manner and can hold a load, the program comprising: The cargo handling vehicle includes a storage unit that stores in advance the height of a platform onto which the cargo is loaded by the forks, the storage unit stores in advance a maximum height among a plurality of possible heights of the mounting table based on a user input when the plurality of possible heights of the mounting table exist; Computer, When loading the load held by the forks onto the platform, the platform is not detected, The data stored in the storage unitfirst means for raising the forks to a height above a maximum height; second means for moving the forks toward the platform until the load on the forks is positioned on the platform; a third means for lowering the forks until the load is placed on the platform; Function as. [Effects of the Invention]

[0008] According to the present invention, loading can be performed suitably with a simple configuration. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a side view of a forklift according to an embodiment. [Figure 2] 1 is a block diagram showing a schematic control configuration of a forklift according to an embodiment. FIG. [Figure 3] 10 is a flowchart showing the flow of a loading process according to the embodiment. [Figure 4] FIG. 10 is a diagram for explaining a loading process according to the embodiment. [Figure 5] FIG. 10 is a diagram for explaining a loading process according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0011] [Forklift configuration] FIG. 1 is a side view of a forklift 1 according to this embodiment. The forklift 1 according to this embodiment is an example of a cargo handling vehicle according to the present invention, and performs cargo handling work including loading cargo L onto a loading platform 41 (see FIG. 4) of a truck 40. The forklift 1 is, although not particularly limited to, an automated guided forklift (AGF) that can operate unmanned (automatically).

[0012] Specifically, the vehicle body 10 of the forklift 1 includes a vehicle body 11, forks 12, a lift (lift) 13, a mast 14, and wheels 15. The mast 14 is provided at the front of the vehicle body 11 and is driven by a drive source (not shown) to tilt the vehicle body 11 forward and backward. The lift 13 is driven by a drive source (not shown) to rise and fall along the mast 14. A pair of left and right forks 12 for holding loads L, pallets 30, etc. are attached to the lift 13. The pair of forks 12 can tilt and rise and fall relative to the vehicle body 11 and move forward and backward by driving the mast 14 and the lift 13, etc. The pallet 30 is a load-receiving platform on which the load L is placed. The pallet 30 is formed in the shape of a short rectangular plate, and has two holes (fork pockets) 32 into which the pair of forks 12 are inserted.

[0013] FIG. 2 is a block diagram showing a schematic control configuration of the forklift 1. As shown in FIG. As shown in this figure, in addition to the above configuration, the forklift 1 is equipped with a travel drive unit 21, a load handling drive unit 22, a load sensor 23, an operation unit 24, a display unit 28, a communication unit 29, a position measurement device 25, a memory unit 26, and a control unit 27.

[0014] The travel drive unit 21 includes a travel motor and a steering motor (both not shown) that are drive sources for traveling the forklift 1. The travel motor drives the drive wheels of the wheels 15. The steering motor rotates the steering wheels of the wheels 15 (performs a steering operation). The cargo handling drive unit 22 includes a cargo handling actuator (not shown) which is a drive source for the cargo handling operation of the forklift 1. The cargo handling actuator is a drive source for performing various operations such as raising and lowering the lifting body 13 and tilting the mast 14.

[0015] The load sensor 23 is a sensor that detects the load (load) of the cargo handling drive unit 22 (cargo handling actuator). The load sensor 23 includes, for example, a hydraulic sensor that detects the hydraulic pressure of a hydraulic actuator that raises and lowers the lifting body 13.

[0016] The operation unit 24 is an operation means by which a driver performs various operations during, for example, manned (manual) driving. The operation unit 24 includes, for example, a steering wheel, pedals, levers, various buttons, etc., and outputs operation signals to the control unit 27 according to the operation content of these. Display unit 28 is, for example, a liquid crystal display, an organic electroluminescence display, or other display, and displays various information based on a display signal input from control unit 27. Display unit 28 may be a touch panel that also serves as part of operation unit 24. Display unit 28 may also include an audio output unit that is capable of outputting audio. The communication unit 29 is a communication device capable of sending and receiving various types of information to and from a management server or the like.

[0017] The position measurement device 25 measures the position of the forklift 1 itself. There are no particular limitations on the specific configuration of the position measurement device 25, and it may be one that uses a GNSS (Global Navigation Satellite System), for example. Alternatively, it may be one that uses a sensor (such as an inertial measurement unit) that measures the traveling direction and a traveling distance sensor to measure the position by sequentially integrating the direction and distance traveled over a very short period of time, or one that uses an optical sensor to detect reflectors (markers) placed at various locations in the work area and compares the detected reflectors with preset reflector placement information to measure the position of the forklift 1.

[0018] The storage unit 26 is a memory configured, for example, by RAM (Random Access Memory) or ROM (Read Only Memory), and stores various programs and data, and also functions as a work area for the control unit 27. The storage unit 26 of this embodiment stores in advance a loading program 260 for executing the loading process (see FIG. 3) described below. The control unit 27 is configured with, for example, a CPU (Central Processing Unit) and controls the operation of each part of the forklift 1. Specifically, the control unit 27 loads a program pre-stored in the storage unit 26 and executes various processes in cooperation with the loaded program.

[0019] [Loading process] Next, the operation of the forklift 1 during loading operation will be described. FIG. 3 is a flowchart showing the flow of the loading process, and FIGS. 4 and 5 are diagrams for explaining the loading process.

[0020] The loading process is executed when the forklift 1 loads the load L onto the loading platform 41 of the truck 40. The loading process is executed by the control unit 27 of the forklift 1 reading and executing the loading program 260 from the memory unit 26. In the following description, the side closer to the forklift 1 in the front-to-back direction (depth direction) as viewed from the forklift 1 may be referred to as the "front side" and the side further away from the forklift 1 as the "rear side."

[0021] 3, when the loading process is executed, the control unit 27 first picks up the load L on the pallet 30 from, for example, a warehouse or the like with the forks 12 (step S1). Note that the loading process may be executed only during loading of the load handling work including picking up and transporting the load.

[0022] Next, the control unit 27 causes the forklift 1 to travel (move) along a predetermined travel path and stops the forklift 1 with the vehicle body 10 facing directly to the side of the loading platform 41 of the truck 40 (step S2; FIG. 4(a)). "Facing the vehicle body 10 directly to the side of the loading platform 41" means that the front of the vehicle body 10 faces the loading platform 41 at the side of the truck 40 (however, it is sufficient that the vehicle body 10 faces the loading platform 41 within a predetermined angle range). The truck 40 has the loading platform 41 exposed with the front gate (side gate) 42 of the loading platform 41 open. When transporting the load L (pallet 30), the forklift 1 moves with the forks 12 positioned at a relatively low height (for example, 300 mm from the ground). It is assumed that the forklift 1 and the loading platform 41 are both approximately horizontal.

[0023] Next, the control unit 27 raises the lifting body 13 (forks 12) to a height exceeding the maximum height of the expected height of the loading platform 41 (step S3; FIG. 4(b)). For example, if there are multiple types of trucks 40 (40A to 40C) that can be loaded and the heights of their beds 41 (41A to 41C) are different, the forks 12 are raised to a height that exceeds the highest bed 41C. In this embodiment, the forks 12 are raised to a position that is a predetermined height h1 higher than the upper surface 41a of the highest bed 41C. The expected maximum height of the loading platform 41 and the predetermined height h1 (or the sum of these) are set (input) in advance and stored in the memory unit 26. The height h1 is not particularly limited, but is, for example, the minimum height at which contact between the loading platform 41 and the pallet 30 can be reliably avoided even when expected error factors are taken into consideration.

[0024] Next, the control unit 27 moves the forks 12 closer to the loading platform 41 until the load L is located at a predetermined loading position (depth position) (step S4; FIG. 5(a)). The predetermined loading position is a depth position where the load L on the forks 12 is located on the loading platform 41, and for example, a position (coordinate) is set in advance. In this case, the approaching manner of the forks 12 includes the forward movement of at least one of the vehicle body 10 and the forks 12.

[0025] Next, the control unit 27 lowers the lifting body 13 (forks 12) to lower the load L onto the loading platform 41 (step S5; FIG. 5(b)).

[0026] Next, the control unit 27 determines whether or not the load L has been properly placed on the loading platform 41 based on the detection result of the load sensor 23 (step S6). Specifically, in this step, the control unit 27 determines whether the load (load) of the lifting body 13 that lifts and lowers the forks 12 has decreased sufficiently (for example, to a predetermined threshold or less) by detecting the hydraulic pressure of the hydraulic actuator that lifts and lowers the lifting body 13 in the cargo handling drive unit 22 with the load sensor 23. Then, when the load of the lifting body 13 has decreased sufficiently, the control unit 27 determines that the load L has been properly placed on the platform 41 (the weight of the load L is supported by the platform 41 and not by the forks 12). In this step S6, the forks 12 are gradually lowered, and if the load on the lifting body 13 is not relieved even when the forks 12 are lowered to the height where the upper surface 41a of the loading platform 41 should be, it may be determined that the load L is not properly placed on the loading platform 41. Furthermore, in order to accurately measure whether the load on the lifting body 13 has been sufficiently reduced, it is preferable to periodically (for example, before work begins on the day of work) calibrate the load sensor 23 in an unloaded state.

[0027] In step S6, if it is determined that the load L is not properly placed on the loading platform 41 (the forks 12 are still supporting the weight of the load L) (step S6; No), the control unit 27 stops the vehicle body 10, notifies the management server or nearby workers, etc. that an abnormality has occurred (step S7), and then proceeds to step S9, which will be described later. In this case, the notification method is not particularly limited, and may include transmitting a notification signal to the management server, displaying a warning on the display unit 28, or outputting a warning sound.

[0028] On the other hand, if it is determined in step S6 that the load L has been properly placed on the loading platform 41 (step S6; Yes), the control unit 27 causes the forklift 1 to move backward and remove the forks 12 from the holes 32 in the pallet 30 (step S8). This completes the loading of the load L (pallet 30) onto the loading platform 41.

[0029] Next, the control unit 27 determines whether or not to end the loading process (step S9), and if it determines not to end it (step S9; No), it shifts the process to the above-mentioned step S1 and continues the loading work. Then, when it is determined that the loading process should be ended, for example, due to the end of the loading work (step S9; Yes), the control unit 27 ends the loading process.

[0030] [Technical effect of this embodiment] As described above, according to this embodiment, when loading a load L held by the forks 12 onto the loading platform 41, the forks 12 are raised to a height exceeding the maximum height of the expected height of the loading platform 41, the forks 12 are moved closer to the loading platform 41 until the load L on the forks 12 is positioned on the loading platform 41, and the forks 12 are lowered until the load L is placed on the loading platform 41. This allows the load L to be loaded onto the loading platform 41 in an optimal manner, unlike conventional methods, without the need for cooperation with a management system that has truck information or the installation of a sensor or the like that detects the loading platform height. Therefore, compared to the conventional method, loading can be performed preferably with a simpler configuration. Furthermore, loading can be performed particularly effectively when multiple types of trucks 40 with different heights of loading platforms 41 arrive multiple times.

[0031] Furthermore, according to this embodiment, it is determined whether or not the load L is placed on the loading platform 41 based on the detection result of the load sensor 23 that detects the load on the lifting body 13. A load sensor that measures the load of the load handling drive unit is installed as standard in a typical forklift, so in that sense, there is no need to install an additional sensor, and the placement state of the load L can be suitably and simply determined.

[0032] [others] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments (including modifications). For example, in the above embodiment, in step S3 of the loading process, the forks 12 are raised while facing the loading platform 41, but the forks 12 may be raised before facing the loading platform 41 in step S2. However, in this case, there is a risk that the speed may be limited due to deterioration in the balance of the vehicle body 10 while traveling, or that the load L may come into contact with a low ceiling or beams during transportation as the load L is raised. Furthermore, the forklift 1 does not need to stop in steps S2 and S3 as long as the forks 12 are raised so that the vehicle body 10 does not come into contact with the loading platform 41 (truck 40). For example, the forklift 1 may raise the forks 12 while moving forward toward the loading platform 41.

[0033] In the above embodiment, in step S6 of the loading process, it is determined whether or not the load L has been properly placed on the loading platform based on the detection result of the load sensor 23 that detects the load on the actuator that drives the lifting body 13. However, this determination method is not particularly limited, and for example, the load on the actuator may be measured by a method other than hydraulic pressure measurement, or the determination may be made based on image information acquired by a camera that photographs the top of the loading platform 41.

[0034] In the above embodiment, an example has been described in which the load L is loaded onto the bed 41 of the truck 40. However, the loading platform according to the present invention is not limited to the bed of the truck, and may be, for example, a shelf (board) or the like, as long as it is a platform-like portion that is higher than the ground (floor) and on which the load is placed.

[0035] In the above embodiment, the forklift 1 operates independently, but it may also be linked to a higher-level management system (management server) that controls the operation of the forklift 1, including position guidance. Even in this case, the management system does not need to detect which truck has come to load the forklift, in order to obtain the height of the loading platform.

[0036] In the above embodiment, the forklift 1 is an unmanned transport forklift. However, the cargo handling vehicle according to the present invention includes vehicles that can be operated by a person (including remote control) and vehicles that can switch between manned and unmanned operation. The present invention can also be used as an assist function for manned operation. Furthermore, the cargo handling vehicle according to the present invention is not limited to a forklift, as long as it can move while holding a load with forks (or similar), but also includes, for example, an automated guided vehicle (AGV) that moves without a driver. In addition, the details shown in the above embodiment can be modified as appropriate without departing from the spirit of the invention. [Explanation of symbols]

[0037] 1. Forklift (cargo handling vehicle) 10. Body 12 forks 13 Elevating body 22 Load handling drive unit (drive means) 23 Load sensor (detection means) 27 Control unit (control means) 28 Display unit (notification means) 30 palettes 40 tracks 41 Cargo bed (loading platform) 41a Top side 260 Loading program (loading control program) L load

Claims

1. A drivable vehicle body, a fork that is provided on the vehicle body so as to be able to rise and fall and that can hold a load; a storage unit that stores in advance the height of a platform onto which the load is to be loaded by the forks; a control means; Equipped with the storage unit stores in advance a maximum height among a plurality of possible heights of the mounting table based on a user input when the plurality of possible heights of the mounting table exist; The control means a first means for lifting the forks to a height exceeding a maximum height stored in the memory unit without detecting the loading platform when loading the load held by the forks onto the loading platform; a second means for moving the forks toward the platform until the load on the forks is positioned on the platform; a third means for lowering the forks until the load is placed on the platform; Including, Loading vehicle.

2. a driving means for raising and lowering the forks; a detection means for detecting a load on the driving means, The third means determines whether or not the load is placed on the platform based on the detection result of the detection means. The cargo handling vehicle according to claim 1.

3. and a notification means for notifying a determination result when the third means determines that the load is not placed on the platform. The cargo handling vehicle according to claim 2.

4. The cargo handling vehicle is an unmanned vehicle that operates without a driver. The cargo handling vehicle according to any one of claims 1 to 3.

5. A method for controlling loading of a cargo handling vehicle including a travelable vehicle body and a fork that is provided on the vehicle body in a manner that allows it to be raised and lowered and that can hold a load, comprising: The cargo handling vehicle includes a storage unit that stores in advance the height of a platform onto which the cargo is loaded by the forks, the storage unit stores in advance a maximum height among a plurality of possible heights of the mounting table based on a user input when the plurality of possible heights of the mounting table exist; The control means a first step of lifting the forks to a height exceeding a maximum height stored in the memory unit without detecting the loading platform when loading the load held by the forks onto the loading platform; a second step of moving the forks toward the platform until the load on the forks is positioned on the platform; a third step of lowering the forks until the load is placed on the platform; A loading control method that performs the above.

6. A loading control program for a cargo handling vehicle including a travelable vehicle body and a fork that is provided on the vehicle body in a liftable manner and can hold a load, the program comprising: The cargo handling vehicle includes a storage unit that stores in advance the height of a platform onto which the cargo is loaded by the forks, the storage unit stores in advance a maximum height among a plurality of possible heights of the mounting table based on a user input when the plurality of possible heights of the mounting table exist; Computer, a first means for lifting the forks to a height exceeding the maximum height stored in the memory unit without detecting the loading platform when loading the load held by the forks onto the loading platform; second means for moving the forks toward the platform until the load on the forks is positioned on the platform; a third means for lowering the forks until the load is placed on the platform; A loading control program that acts as a

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