Unmanned conveyance vehicle

Abstract

To provide an unmanned conveyance vehicle capable of precisely detecting an obstruction correspondingly to a width of a pallet to be loaded above, while detecting the obstruction below the unmanned conveyance vehicle.SOLUTION: An unmanned conveyance vehicle 1 that enters below a pallet 19 loaded on a support body 15 to carry out loading / unloading work of the pallet 19 comprises: a machine base 3; a lifter 5 provided on a top part of the machine base 3 to lift / lower the pallet 19; a drive wheel 7 provided on a bottom part of the machine base 3 to move the machine base 3; a first obstruction sensor 9 that detects the obstruction in a direction of travel of the machine base 3; a second obstruction sensor 11 provided above the first obstruction sensor 9 to detect the obstruction in the upper direction of travel of the machine base 3; and a control unit 13 that controls the lifter 5, the drive wheel 7, the first obstruction sensor 9, and the second obstruction sensor 11.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an automated guided vehicle. [Background technology]

[0002] In recent years, automated guided vehicles that can automatically move materials without human intervention are being used in factories and logistics sites. For example, Patent Document 1 discloses an automated guided vehicle that enters the bottom of a pallet with legs with its platform lowered, raises the platform to place the pallet on the platform, and transports the pallet. The entry guidance device of this automated guided vehicle controls the entry of the vehicle to the bottom of the pallet by an approach sensor at the time of entry and a side sensor after entry. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-182744 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, a sensor detects the position of the legs of a pallet and controls the movement of the automated guided vehicle. However, because the width of the detection range of the sensor is narrower than the width of the pallet, it may be difficult for the pallet to avoid various obstacles when the automated guided vehicle is traveling. In other words, there is a problem that the automated guided vehicle cannot travel smoothly while reliably avoiding obstacles when loading and unloading the pallet and transporting the pallet.

[0005] Therefore, an object of the present invention is to provide an unmanned guided vehicle that can detect obstacles below the vehicle while accurately detecting obstacles in accordance with the width of a pallet loaded above. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention employs the following means. In other words, the unmanned guided vehicle of the present invention is an unmanned guided vehicle that enters beneath a pallet placed on a stand (support) to load and unload the pallet, and is equipped with a machine base, a lifter provided on the upper part of the machine base for raising and lowering the pallet, drive wheels provided on the lower part of the machine base for moving the machine base, a first obstacle sensor that detects obstacles in the direction of travel of the machine base, a second obstacle sensor located above the first obstacle sensor that detects obstacles in the upward direction of travel of the machine base, and a control unit that controls the lifter, the drive wheels, the first obstacle sensor, and the second obstacle sensor.

[0007] In one aspect of the present invention, the second obstacle sensor is provided on the lifter and is linked to the up and down movement of the lifter.

[0008] In one embodiment of the present invention, when a pallet is not loaded, the detection widths of the first obstacle sensor and the second obstacle sensor are set to the width of the machine base, and when a pallet is loaded, the detection widths of the first obstacle sensor and the second obstacle sensor are set to the width of the loaded pallet, and when a pallet is loaded and moved to the placement table, the detection width of the first obstacle sensor is set to the width of the machine base and the detection width of the second obstacle sensor is set to the width of the loaded pallet. Effect of the Invention

[0009] According to the present invention, it is possible to provide an unmanned guided vehicle that can detect obstacles below the unmanned guided vehicle while accurately detecting obstacles in accordance with the width of a pallet loaded above. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a plan view for explaining the operation of the automated guided vehicle according to the embodiment of the present invention, showing a pallet placed on a stand. [Diagram 2] FIG. 2 is a side view of FIG. [Diagram 3] FIG. 2 is a plan view for explaining the operation of the automated guided vehicle according to the embodiment of the present invention, showing a pallet being loaded on the automated guided vehicle; [Figure 4] FIG. 4 is a side view of FIG. [Diagram 5] FIG. 1 is a plan view for explaining the operation of an automated guided vehicle according to a prerequisite technique of the present invention, showing a pallet placed on a stand. [Figure 6] FIG. 6 is a side view of FIG. 5. [Figure 7] FIG. 1 is a plan view for explaining the operation of an automated guided vehicle according to a prerequisite technique of the present invention, showing a pallet being loaded onto the automated guided vehicle. [Figure 8] FIG. 8 is a side view of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (Prerequisite technology) Before describing the embodiments of the present invention, the premise technology of the present invention will be described. Fig. 5 is a plan view for explaining the operation of an automated guided vehicle according to the premise technology of the present invention, and Fig. 6 is a side view of Fig. 5. An automated guided vehicle 100 according to the premise technology of the present invention includes a machine base 3, a lifter 5, driving wheels 7, and an obstacle sensor 21. The lifter 5 is provided on the upper part of the machine base 3 and raises and lowers a loaded pallet 19. The driving wheels 7 are provided on the lower part of the machine base 3 and move the machine base 3. The obstacle sensor 21 detects obstacles in the traveling direction of the machine base 3.

[0012] In Fig. 5 and Fig. 6, a pallet 19 is placed on a stand (support) 15. The stand 15 is composed of four legs 15a, 15b, 15c, and 15d, and each of the legs 15a to 15d has a base 23 fixed to a floor G, a column 25 extending vertically from the base 23, and a placement portion 27 provided on the upper part of the column 25. The legs 15a to 15d of the stand 15 are arranged to support the four corners of the rectangular plate-shaped pallet 19, and the placement portion 27 provided on the upper part of each of the legs 15a to 15d is provided with a vane 29, and is configured to stably guide the four corners of the pallet 19 and hold it on the placement portion 27 when the pallet 19 is placed.

[0013] 5 and 6 show a state in which the automated guided vehicle 100 enters under the pallet 19 with the lifter 5 lowered in order to load the pallet 19 placed on the stand 15 onto the lifter 5 for transport. When the automated guided vehicle 100 enters under the pallet 19, the automated guided vehicle 100 detects obstacles with the obstacle sensor 21 in a detection width K that is the same as the width of the machine base 3 in order to avoid colliding with the legs 15a to 15d of the stand 15 and to avoid other obstacles. After entering under the pallet 19, the automated guided vehicle 100 raises the lifter 5 to lift and load the pallet 19, and transports the pallet 19 to the next destination.

[0014] Fig. 7 is a plan view for explaining the operation of an automatic guided vehicle according to the prerequisite technology of the present invention, showing a pallet being loaded on the automatic guided vehicle. Fig. 8 is a side view of Fig. 7. 7 and 8, the pallet 19 is loaded on the automated guided vehicle 100, and the automated guided vehicle 100, with the lifter 5 raised, enters between the legs 15a to 15d of the stand 15 in order to place the pallet 19 being transported on the stand 15. The automated guided vehicle 100 detects an obstacle with the obstacle sensor 21 at a detection width K that is the same as the width of the machine base 3, and enters between the legs 15a to 15d of the stand 15 so as not to collide with the legs 15a to 15d and the obstacle. After entering a predetermined position, the lifter 5 is lowered and the pallet 19 is placed on the stand 15. The movement of the automated guided vehicle may be performed by any method such as a line tracing method, a landmark method, or SLAM (Simultaneous Localization and Mapping), and the description thereof will be omitted here as it is a known technique. In this base technology, the width of the pallet 19 is greater than the width of the machine base 3 , and the detection width K of the obstacle sensor 21 is set to be the same as the width of the machine base 3 .

[0015] In this base technology, the width of the detection range of the obstacle sensor 21 is narrower than the width of the pallet 19, so that when the automated guided vehicle 100 is driven, it may be difficult for the pallet 19 to avoid various obstacles. That is, there is a problem that the automated guided vehicle 100 cannot drive smoothly while reliably avoiding obstacles when loading and unloading the pallet 19 and transporting the pallet 19. Therefore, in order to transport the pallet 19 more reliably and stably, a method of detection by the obstacle sensor 21 was studied. As a result of the study, the automated guided vehicle of the present invention, an embodiment of which will be described next, was devised.

[0016] (Embodiment) 1 and 3 are plan views for explaining the operation of an automatic guided vehicle according to an embodiment of the present invention, and FIGS. 2 and 4 are side views of FIGS. 1 and 3, respectively. The automatic guided vehicle 1 according to this embodiment includes a machine base 3, a lifter 5, driving wheels 7, a first obstacle sensor 9, a second obstacle sensor 11, and a control unit 13. The lifter 5 is provided on the upper part of the machine base 3 and raises and lowers a loaded pallet 19. The driving wheels 7 are provided on the lower part of the machine base 3 and move the machine base 3. The first obstacle sensor 9 detects obstacles in the traveling direction of the machine base 3. The second obstacle sensor 11 is located above the first obstacle sensor 9 and detects obstacles in the upward traveling direction of the machine base 3. Here, the first and second obstacle sensors may be ultrasonic, infrared, laser, or other sensors that can detect obstacles without contact. In this embodiment, the second obstacle sensor 11 is provided on the lifter 5 and is linked to the up and down movement of the lifter. The control unit 13 controls the lifter 5, the driving wheels 7, the first obstacle sensor 9, and the second obstacle sensor 11. Here, the control includes the movement of the automated guided vehicle 1 by the driving wheels 7, the lifting and lowering operation of the lifter 5 when loading the pallet 19, and the setting of the detection width K1 of the first obstacle sensor 9 and the detection width K2 of the second obstacle sensor 11, which will be described later, and the like.

[0017] 1 and 2 show a state in which a pallet 19 is placed on the stand 15, and the pallet 19 is not loaded on the lifter of the automated guided vehicle 1. The stand 15 has the same configuration as that described in the above-mentioned base technology, and therefore its description is omitted here. In FIG. 1 and FIG. 2, the automated guided vehicle 1 enters the lower part of the pallet 19 with the lifter 5 lowered in order to load the pallet 19 placed on the stand 15. When the automated guided vehicle 1 enters the lower part of the pallet 19, the detection width K1 of the first obstacle sensor 9 and the detection width K2 of the second obstacle sensor 11 are set to the same width as the machine base 3 in order to avoid colliding with the legs 15a to 15d of the stand 15 and to avoid other obstacles, and the automated guided vehicle 1 enters while detecting obstacles. After the automatic guided vehicle 1 enters a predetermined position below the pallet 19, the lifter 5 is raised to lift and load the pallet 19, and the pallet 19 is transported to the next transfer location.

[0018] Fig. 3 is a plan view for explaining the operation of the automatic guided vehicle according to the embodiment of the present invention, showing a pallet 19 loaded on the automatic guided vehicle 1. Fig. 4 is a side view of Fig. 3. 3 and 4 show a state in which a pallet 19 is loaded on the automated guided vehicle 1, and the automated guided vehicle 1 enters between the legs 15a to 15d of the stand 15 with the lifter 5 raised in order to place the pallet 19 being transported on the stand 15. At this time, the detection width K1 of the first obstacle sensor 9 is set to the same width as the machine base 3, and the detection width K2 of the second obstacle sensor 11 is set to the same width as the pallet 19. The automated guided vehicle 1 enters between the legs 15a to 15d while detecting obstacles with the detection widths K1 and K2 set in this way, that is, while detecting obstacles with each obstacle sensor so that the first obstacle sensor 9 does not collide with the legs 15a to 15d of the stand 15 and other obstacles, and so that the second obstacle sensor 11 does not collide with the pallet 19. After entering a predetermined position, the automated guided vehicle 1 lowers the lifter 5 and places the pallet 19 on the platform 15. As with the above-mentioned base technology, the automated guided vehicle may move by any method, such as line tracing, landmarks, or SLAM (Simultaneous Localization and Mapping).

[0019] When the automated guided vehicle 1 is transporting the pallet 19 loaded thereon, the detection width K1 of the first obstacle sensor 9 and the detection width K2 of the second obstacle sensor 11 are set to the same width as the pallet, K1, K2, and the automated guided vehicle 1 moves while detecting obstacles at the detection widths K1, K2. Although this state is not particularly shown, in FIG. 3, the pallet 19 is transported in a state in which the detection width K1 of the first obstacle sensor 9 is set to the same width as the pallet 19, just like the detection width K2 of the second obstacle sensor 11. Here, when transporting the pallet 19 loaded thereon, for stability, the lifter 5 may be lowered at a position sufficiently far from the stand 15 to lower the center of gravity.

[0020] In summary, the detection width K1 of the first obstacle sensor 9 and the detection width K2 of the second obstacle sensor 11 are set as follows. (1) When no pallet 19 is loaded, the detection widths K1, K2 of the first obstacle sensor 9 and the second obstacle sensor 11 are set to the width of the machine base 3. (2) When the pallet 19 is loaded, the detection widths K1, K2 of the first obstacle sensor 9 and the second obstacle sensor 11 are set to the width of the loaded pallet 19. (3) When the pallet 19 is loaded and moved to the stand 15, the detection width K1 of the first obstacle sensor 9 is set to the width of the machine base 3, and the detection width K2 of the second obstacle sensor 11 is set to the width of the loaded pallet 19. When the unmanned guided vehicle 1 moves, if an obstacle is detected by the first obstacle sensor 9 or the second obstacle sensor 11, a predetermined obstacle processing flow procedure is taken, such as avoiding the obstacle, or if avoidance is impossible, stopping the vehicle and sending an alarm to a management server.

[0021] As described above, the automated guided vehicle 1 of this embodiment has the first obstacle sensor 9 and the second obstacle sensor 11 located above the first obstacle sensor 9, so while detecting obstacles below, it can also detect obstacles at the height of the pallet 19 above, and can travel stably while avoiding the obstacles. When the automated guided vehicle 1 enters under the pallet 19 placed on the stand 15 to load the pallet 19, the detection widths K1 and K2 of the first obstacle sensor 9 and the second obstacle sensor 11 are set to the same width as the machine base 3, so that the automated guided vehicle 1 can enter under the pallet 19 without colliding with the legs 15a to 15d of the stand 15 and other obstacles. When the pallet 19 is loaded onto the lifter 5 and transported, the detection widths K1 and K2 of the first obstacle sensor 9 and the second obstacle sensor 11 are set to the same width as the pallet 19, so the pallet 19 can be transported without colliding with an obstacle. When the pallet 19 is placed on the stand 15, the detection width K1 of the first obstacle sensor 9 is set to the same width as the machine base 3, and the detection width K2 of the second obstacle sensor 11 is set to the same width as the pallet 19, so the pallet 19 can be placed on the stand 15 while avoiding collision with the legs 15a-15d of the stand 15 and obstacles in front of the lower part of the machine base 3, and avoiding collision between the pallet 19 above the lifter 5 and obstacles. Furthermore, since the second obstacle sensor 11 is provided on the lifter 5 and moves in conjunction with the up and down movement of the lifter 5, it is possible to appropriately set the detection width K2 of the second obstacle sensor 11 when the pallet 19 is loaded, thereby making it possible to avoid collision between the pallet 19 and an obstacle. Thus, it is possible to provide an automated guided vehicle that can detect obstacles below the vehicle, while also accurately detecting obstacles in accordance with the width of the pallet loaded above.

[0022] In addition, it is possible to select and discard the configurations given in the above embodiment, or to change them to other configurations as appropriate, without departing from the spirit of the present invention. [Explanation of symbols]

[0023] 1,100 Automated Guided Vehicle 3 machines 5 Lifter 7 Driving wheels 9 First Obstacle Sensor 11 Second Obstacle Sensor 13 Control section 15 Stand (support) 19 Palettes 21 Obstacle Sensor K, K1, K2 Obstacle sensor detection width

Claims

1. An automated guided vehicle that enters below a pallet placed on a support to load and unload the pallet, Machine base and a lifter provided on an upper portion of the machine base for raising and lowering the pallet; A drive wheel is provided under the machine base to move the machine base; a first obstacle sensor for detecting an obstacle in a traveling direction of the machine; a second obstacle sensor located above the first obstacle sensor and configured to detect an obstacle in an upward traveling direction of the machine base; a control unit that controls the lifter, the drive wheels, the first obstacle sensor, and the second obstacle sensor.

2. The automated guided vehicle according to claim 1 , wherein the second obstacle sensor is provided on the lifter and is linked to the vertical movement of the lifter.

3. When no pallet is loaded, the detection widths of the first obstacle sensor and the second obstacle sensor are set to the width of the machine base; when a pallet is loaded, the detection widths of the first obstacle sensor and the second obstacle sensor are set to the width of the loaded pallet; 3. The automated guided vehicle according to claim 1, wherein, when a pallet is loaded and the automated guided vehicle is moved to a placement table, a detection width of the first obstacle sensor is set to the width of the machine base, and a detection width of the second obstacle sensor is set to the width of the loaded pallet.

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