Automated guided vehicles

Abstract

To provide an unmanned guided vehicle capable of suppressing a height of a shelf and suppressing a manufacturing cost of the shelf.SOLUTION: There is provided an unmanned guided vehicle including: a vehicle body; a cargo handling device that is provided on the vehicle body and loads and unloads a cargo W with respect to a shelf 20 for storing cargoes; a laser sensor 50 that is provided on the vehicle body and scans a predetermined range around the vehicle body with a laser beam to detect obstacles; and a controller that estimates a self-position based on a laser point detected by the laser sensor 50, wherein the laser sensor 50 is provided at a height at which a laser beam L passes through a dead space Sd of a storage space of the shelf 20, and a height of the laser sensor 50 is the same as a height at which a plurality of reflectors 13 provided separately from the shelf 50 are installed, and when the cargo W loaded and unloaded by the cargo handling device passes through the dead space Sd and shields the laser beam L for detecting a specific reflector 13, the controller estimates a self-location based on the plurality of detectable reflectors 13, excluding the specific reflector 13.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] As a conventional technique related to an automated guided vehicle, for example, a laser-type shelf for an automated guided vehicle and an automated guided vehicle system using the same are known, as disclosed in Patent Document 1.

[0003] The shelf for a laser-type automated guided vehicle disclosed in Patent Document 1 is a shelf for a laser-type automated guided vehicle used for a laser-type automated guided vehicle. The laser-type automated guided vehicle is equipped with a laser scanner that recognizes a reflector installed in a warehouse, and the laser scanner transmits and receives a laser to the reflector while rotating 360 degrees horizontally. The reflector and the laser scanner are installed at a predetermined set height. The shelf for a laser-type automated guided vehicle is equipped with a plurality of luggage spaces that are provided in the left-right and up-down directions and store luggage, a plurality of laser spaces that are provided in the left-right direction and do not store luggage or block the laser, and a frame that defines the luggage spaces and the laser spaces. The luggage spaces have a predetermined first space height. The laser spaces are arranged at the set height and have a second space height smaller than the first space height, and the laser spaces are arranged between the luggage spaces in the up-down direction.

[0004] The shelf for the laser type automated guided vehicle is provided with a plurality of luggage spaces arranged in the left-right and up-down directions for storing luggage, a plurality of laser spaces arranged in the left-right direction for not storing luggage and not blocking the laser, and a frame that defines the luggage spaces and the laser spaces. Furthermore, the automated guided vehicle system disclosed in Patent Document 1 includes this shelf for the laser type automated guided vehicle and a laser type automated guided vehicle. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6598265 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the laser type automated guided vehicle shelf of Patent Document 1, the laser space is arranged between the luggage spaces in the vertical direction, so there is a problem that the shelf height is increased by the amount of the laser space. Also, in the laser type automated guided vehicle shelf of Patent Document 1, the luggage space and the laser space are provided with a frame that defines the luggage space and the laser space, so the number of members that constitute the shelf increases and the manufacturing cost of the shelf increases compared to when there is no frame that defines the luggage space and the laser space.

[0007] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide an unmanned guided vehicle that can reduce the height of shelves and the manufacturing costs of the shelves. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides a vehicle body and a shelf provided on the vehicle body for storing luggage. Cargo storage area In an unmanned guided vehicle, the unmanned guided vehicle includes a loading device for loading and unloading a load onto and from the vehicle body, a laser sensor provided on the vehicle body for scanning a laser beam within a predetermined range around the vehicle body, and a control device for estimating the vehicle's own position based on a laser point detected by the laser sensor. Cargo storage area Storage space for loads space is set above Required to lift the load from the shelf The laser sensor is installed at a height that passes through a dead space, and the height of the laser sensor is the same as the height at which a plurality of high-brightness components are installed separately from the shelf, and when cargo being loaded or unloaded by the loading and unloading device passes through the dead space and blocks the laser light that detects a specific high-brightness component among the multiple high-brightness components, the control device estimates its own position based on the multiple detectable high-brightness components excluding the specific high-brightness component.

[0009] In the present invention, even if the cargo being loaded and unloaded by the loading and unloading device blocks the laser light that detects a specific high-luminance component among multiple high-luminance components, the control device estimates its own position based on the multiple detectable high-luminance components excluding the specific high-luminance component. Therefore, it is not necessary to provide a dedicated laser space for passing the laser light in addition to the storage space including the dead space on the shelf. As a result, the space efficiency of the shelf is improved, the height of the shelf is reduced, and the number of shelf components can be reduced, thereby reducing manufacturing costs.

[0010] In the above-mentioned automated guided vehicle, the control device may be configured to estimate its own position based on laser points of at least three of the high-brightness members that can be detected by the laser sensor when a laser light that detects the specific high-brightness member is blocked. In this case, when the laser light detecting a specific high-luminance member is blocked, the control device estimates its own position based on the laser points of at least three high-luminance members. By estimating its own position based on the laser points of at least three high-luminance members detected by the laser sensor, it is possible to accurately estimate its own position.

[0011] In addition, the above-mentioned unmanned guided vehicle may be equipped with a drive wheel provided on the vehicle body and an encoder for detecting the amount of rotation of the drive wheel, and the control device may be configured to use the amount of rotation output from the encoder as odometry information when laser light detecting the specific high-brightness component is blocked and a plurality of high-brightness components detectable for estimating the self-position are insufficient, and to estimate the self-position based on the odometry information. In this case, since the amount of rotation of the drive wheels detected by the encoder is used as odometry information, there is no need to add a separate device for self-position estimation.

[0012] In the above-mentioned automated guided vehicle, the laser sensor is The above The vehicle may be configured to include a sensor rotating portion that is capable of scanning the entire periphery of the vehicle body with laser light. In this case, the laser sensor can scan laser light all around the vehicle body, so that even if multiple high-brightness components necessary for estimating the vehicle's position are provided in different positions, the multiple high-brightness components necessary for estimating the vehicle's position can be detected more reliably. Effect of the Invention

[0013] According to the present invention, it is possible to provide an automated guided vehicle that can reduce the height of the shelves and the manufacturing costs of the shelves. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a plan view of a warehouse in which unmanned forklifts and shelves according to a first embodiment are arranged. [Diagram 2] FIG. 1(a) is a front view showing a part of a shelf, and FIG. [Diagram 3] FIG. 1 is a side view of an unmanned forklift according to a first embodiment. [Figure 4] FIG. 1 is a schematic configuration diagram of an unmanned forklift. [Diagram 5] 1A is a side view showing the unmanned forklift facing the load it is removing, FIG. 1B is a side view showing the unmanned forklift removing a load from a shelf, and FIG. 1C is a side view showing the unmanned forklift after it has removed the load from the shelf. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] (First embodiment) Hereinafter, an unmanned guided vehicle according to a first embodiment will be described with reference to the drawings. The unmanned guided vehicle of this embodiment is an unmanned reach-type forklift capable of autonomous travel. In this embodiment, an unmanned reach-type forklift used in a warehouse where shelves are installed will be described as an example.

[0016] First, a warehouse 10 in which an unmanned reach forklift 30 shown in Fig. 1 (hereinafter simply referred to as "unmanned forklift") is used will be described. A plurality of (four) shelves 20 are arranged in the warehouse 10. A travel path 12 along which the unmanned reach forklift 30 can travel is formed between the wall 11 of the warehouse 10 and the shelves 20 and between the shelves 20. The wall 11 of the warehouse 10 includes a wall 11A having an entrance / exit 14, a wall 11B facing the wall 11A, and walls 11C and 11D connecting the wall 11A and the wall 11B.

[0017] A plurality of reflecting materials 13 are attached to the walls 11 of the warehouse 10. Two reflecting materials 13A and 13B are attached to the wall 11A with a gap between them. Two reflecting materials 13C and 13D are attached to the wall 11B. Four reflecting materials 13E, 13F, 13G, and 13H are attached to the wall 11C with a gap between them. Four reflecting materials 13J, 13K, 13L, and 13M are attached to the wall 11D.

[0018] Next, the shelves 20 will be described. As shown in FIG. 1, four shelves 20 are installed in pairs. As shown in FIG. 2(a) and FIG. 2(b), the shelves 20 have a plurality of support columns 21 arranged at a predetermined interval, a plurality of horizontal members 22, 23 connecting the support columns 21, and a load storage section 24 that is partitioned by the support columns 21 and the horizontal members 22, 23 and stores the load W. The shelves 20 of this embodiment have seven openings along the travel path 12 and three load storage sections 24 in upper and lower stages. That is, one shelf 20 has 21 load storage sections 24. The load W is placed on the floor surface of the load storage section 24 at the lowest stage, but the load storage sections 24 at the second and third stages are provided with a receiving member (not shown) for receiving the load W. It is to be noted that a receiving member may be provided in the load storage section 24 at the lowest stage so that the load W is placed on the receiving member instead of on the floor surface. Moreover, the loads W stored on the shelf 20 of this embodiment are of the same size.

[0019] The storage space of the load storage section 24 includes a load space Sw, which is equal to the volume of the load W, as well as a dead space Sd required for lifting the load W from the floor surface or the receiving member when the load W is moved in or out of the shelf 20. In the load storage section 24, the dead space Sd corresponds to the space between the upper surface of the load W and the cross member 23 above the load W when the load W is stored in the load storage section 24. Therefore, when the load W is not stored in the load storage section 24, the dead space Sd is located above the load space Sw.

[0020] Next, the unmanned forklift 30 will be described. As shown in Fig. 3, the unmanned forklift 30 has a loading device 33 that can move forward and backward between a pair of left and right reach legs 32 provided at the front of a vehicle body 31. Front wheels 34 are provided on the reach legs 32, and the rear of the vehicle body 31 is provided with rear wheels 35 as steering wheels and drive wheels, and caster wheels (not shown) for further stabilizing the posture of the vehicle body 31.

[0021] The loading / unloading device 33 is a device for loading / unloading cargo, and includes an outer mast 36 supported by the left and right reach legs 32, and an inner mast 37 supported on the outer mast 36 so as to be able to rise and fall. A pair of left and right forks 38 are supported on the inner mast 37 so as to be able to rise and fall. A lift cylinder 39 for raising and lowering the inner mast 37 is fixed to the rear of the outer mast 36. Therefore, the unmanned forklift 30 can load and unload cargo W onto and from the shelf 20 by using the loading / unloading device 33.

[0022] As shown in FIG. 4, the unmanned forklift 30 includes a traveling drive device 40 that drives the rear wheels 35. The traveling drive device 40 includes a drive motor 41 for rotating the rear wheels 35 and a motor driver 42 that drives the drive motor 41. The motor driver 42 controls the rotation speed of the drive motor 41 in response to a command from a control device 43. The control device 43 controls each part of the unmanned forklift 30. The control device 43 includes a CPU 44 and a storage unit 45 including RAM, ROM, and the like. The control device 43 may include dedicated hardware that executes at least a part of the various processes, such as an application specific integrated circuit (ASIC). The control device 43 may be configured as a circuit including one or more processors that operate according to a computer program, one or more dedicated hardware circuits such as ASIC, or a combination thereof.

[0023] The storage unit 45 stores program codes or instructions configured to cause the CPU 44 to execute processing. The storage unit 45 stores various programs for controlling the unmanned forklift 30, as well as an environmental map relating to the moving space in which the unmanned forklift 30 moves. A technology for simultaneously performing self-location estimation and constructing an environmental map is called SLAM (Simultaneous Localization and Mapping). The storage unit 45, i.e., the computer-readable medium, includes anything that can be accessed by a general-purpose or dedicated computer.

[0024] In this embodiment, an encoder 46 is provided to detect the amount of rotation of the axle (not shown) of the rear wheels 35 serving as steering wheels and drive wheels. The amount of rotation of the axle detected by the encoder 46 is transmitted to the control device 43. The amount of rotation of the axle of the rear wheels 35 output from the encoder 46 is odometry information for estimating the self-position of the unmanned forklift 30.

[0025] 1, the vehicle body 31 is provided with a head guard 47, and a laser sensor 50 is provided on the upper part of the head guard 47. The laser sensor 50 in this embodiment is a laser range finder (LRF). A laser range finder is a distance meter that measures distance by irradiating a laser to the surroundings and receiving light reflected from the area where the laser hits.

[0026] The laser sensor 50 has a sensor base 51 fixed to the head guard 47 and a sensor rotating unit 52 that rotates relative to the sensor base 51. The sensor rotating unit 52 has a light transmitter / receiver 53 that transmits and receives laser light. When the road surface is horizontal, the light transmitter / receiver 53 irradiates laser light in the horizontal direction, and scans a predetermined range of 360° around the vehicle body 31 by the rotation of the sensor rotating unit 52. That is, as shown in FIG. 1, the laser sensor 50 is a two-dimensional laser sensor that scans a search range E indicated by a circle of a predetermined radius R centered on the sensor rotating unit 52. Also, when an obstacle is present in the search range E of the laser light, the light transmitter / receiver 53 receives the laser light reflected from the obstacle. When an obstacle is present in the search range E, the laser sensor 50 detects the obstacle as a laser point cloud, and the control device 43 acquires the measured distance and direction from the laser sensor 50 to each laser point in the laser point cloud, as well as the brightness of each laser point. The measured distance is calculated based on the coordinate data of the laser point.

[0027] The height of the light transmitting / receiving body 53 from the ground (ground clearance) is set according to the position of the shelf 20. Specifically, the ground clearance of the light transmitting / receiving body 53 of the laser sensor 50 is set so that the laser light passes through the dead space Sd of the second-stage load storage section 24 of the shelf 20. Therefore, in addition to the state where the load W is not present in the second-stage load storage section 24, the laser light of the laser sensor 50 passes through the dead space Sd when the load W is stored in the load storage section 24. In addition, in accordance with the ground clearance condition based on the dead space Sd, the light transmitting / receiving body 53 is preferably provided at a position where the laser light is not blocked by the loading device 33 or the like when the unmanned forklift 30 is traveling (when the forks 38 are located close to the floor surface). Incidentally, in the autonomous traveling of the unmanned forklift 30, the unmanned forklift 30 does not travel with the load W raised, except when the load W is entering or leaving the shelf 20.

[0028] In this embodiment, the wall 11 of the warehouse 10 is provided with a plurality of reflectors 13, and the reflectors 13 are attached to the wall 11 at a height that matches the height above the ground of the light transmitting / receiving body 53. The reflecting surface of the reflector 13 is formed in a cylindrical shape. Therefore, the reflector 13 reflects the laser light of the laser sensor 50 of the unmanned forklift 30 with a higher reflectance than other obstacles. The reflector 13 corresponds to a high-brightness member. In this embodiment, the reflector 13 is attached to the wall 11 so that the laser sensor 50 can detect at least four reflectors 13 regardless of which frontage of the shelf 20 the unmanned forklift 30 faces (see FIG. 1). In addition, the reflector 13 is provided on the wall 11 at a position that does not face the frontage of the shelf 20 so that three or more reflectors 13 can be detected.

[0029] When the laser sensor 50 receives the reflected laser light, the control device 43 detects a plurality of laser points of the reflecting material 13 as a high-intensity laser point cloud. Then, in order to estimate the self-position of the unmanned forklift 30 with high accuracy, the control device 43 estimates the self-position of the unmanned forklift 30 by detecting the high-intensity laser point clouds of three or more reflecting materials 13. It is also possible for the control device 43 to estimate the self-position based on the high-intensity laser point clouds of four or more reflecting materials 13.

[0030] Incidentally, when the unmanned forklift 30 moves the load W into or out of the load storage section 24 on the second level of the shelf 20, the load W received by the forks 38 is positioned above the receiving member of the load storage section 24, and the vehicle body 31 is moved, so that the load W is moved into or out of the load storage section 24. When the load W received by the forks 38 is positioned above the receiving member of the load storage section 24, most of the dead space Sd is filled by the load W received by the forks 38. This causes the laser light of the laser sensor 50 to be blocked. When the laser light is blocked by the load W, the laser light cannot pass through the dead space Sd and loses sight of the reflective material 13.

[0031] Even if the control device 43 cannot detect the high-intensity laser point cloud of the reflector 13 due to the load W entering or leaving the vehicle, the control device 43 estimates the self-position of the unmanned forklift 30 without immediately losing sight of the self-position. The control device 43 estimates the self-position based on the high-intensity laser point clouds of multiple (three) reflectors 13, but in a state in which the load W does not block the laser light, the control device 43 always detects the high-intensity laser point clouds of four or more reflectors 13. Therefore, when a specific reflector 13 used for estimating the self-position is not detected, the control device 43 uses the high-intensity laser point clouds of three reflectors 13, including the high-intensity laser point cloud of the reflector 13 not used for estimating the self-position, for self-position estimation.

[0032] When the load / unloading of the load W into / from the load storage section 24 of the shelf 20 is completed and the laser light passes through the dead space Sd, the control device 43 estimates its own position based on the high-intensity laser point clouds of the three reflectors 13, including the high-intensity laser point cloud of the reflector 13 used before the laser light was blocked.

[0033] Next, the loading and unloading of the shelf 20 by the unmanned forklift 30 of this embodiment will be described. A case will be described in which the unmanned forklift 30 in the position shown in FIG. 1 takes out the load W placed in the load storage section 24 of the facing shelf 20. As shown in FIG. 5(a), before the loading device 33 lifts the load W, the laser light of the laser sensor 50 passing through the dead space Sd is not blocked. At this time, the laser sensor 50 detects five reflectors 13A, 13B, 13F, 13J, and 13K (see FIG. 1). Therefore, the control device 43 estimates the self-position of the unmanned forklift 30 based on the high-intensity laser point cloud of three reflectors 13 (the reflectors 13A, 13B, and 13K in order of proximity to the unmanned forklift 30) from among the reflectors 13A, 13B, 13F, 13J, and 13K.

[0034] Next, as shown in Fig. 5(b), the loading device 33 lifts the load W, causing the load W to block the laser light passing through the dead space Sd. As a result, the control device 43 is no longer able to detect the high-intensity laser point cloud of the reflector 13K. When the laser sensor 50 is no longer able to detect the reflector 13K, the control device 43 estimates its own position based on the detected high-intensity laser point cloud of the reflector 13J and the high-intensity laser point clouds of the reflectors 13A and 13B.

[0035] Next, as shown in Fig. 5(c), when removal of the load W from the load storage section 24 of the shelf 20 is completed, the load W no longer blocks the laser light, and the laser light passes through the dead space Sd again. Therefore, the laser sensor 50 detects the reflector 13K again, and the control device 43 detects the high-intensity laser point cloud of the reflector 13K. Therefore, the control device 43 estimates its own position based on the high-intensity laser point clouds of the three reflectors 13A, 13B, and 13K used before the laser light was blocked.

[0036] Furthermore, when the unmanned forklift 30 puts or takes out the load W into or from the load storage section 24 of the facing shelf 20, the control device 43 becomes unable to detect the high-intensity laser point cloud of a specific reflector 13. In this case, the control device 43 estimates its own position based on the high-intensity laser point clouds of three reflectors 13 including the high-intensity laser point cloud of the reflector 13 that was not used in estimating its own position.

[0037] When the load W is moved in or out of the load storage section 24 on the third level of the shelf 20, the load W blocks the laser light passing through the dead space Sd, but in this case too, the control device 43 estimates its own position based on the high-intensity laser point clouds of the three reflectors 13 including the high-intensity laser point cloud of the reflector 13 that was not used to estimate its own position. When the laser light passes through the dead space Sd again, the control device 43 estimates its own position based on the high-intensity laser point clouds of the three reflectors 13 that were used before the laser light was blocked.

[0038] In this embodiment, when a specific reflector 13 used for estimating the self-position is not detected, the control device 43 estimates the self-position based on the high-intensity laser point clouds of three reflectors 13 including the high-intensity laser point cloud of the reflector 13 not used for estimating the self-position. If the laser sensor 50 cannot detect three or more reflectors 13 for some reason when the load W is moved in or out of the shelf 20 and blocks the laser light, the control device 43 estimates the self-position based on the amount of rotation output from the encoder 46, which is odometry information.

[0039] Specifically, when the load W blocks the laser light, the control device 43 controls the travel drive device 40 so that the unmanned forklift 30 approaches or moves away from the shelf 20. The control device 43 can calculate the amount of movement (distance and direction) of the unmanned forklift 30 in a given time by integrating the amount of rotation during the movement of the unmanned forklift 30. Therefore, the self-position of the unmanned forklift 30 can be estimated by using the odometry information.

[0040] Once the removal of the load W from the load storage section 24 of the shelf 20 is completed and the load W no longer blocks the laser light, the specific reflector 13 used to estimate the load's own position will be detected, and the control device 43 will again estimate the load's own position based on the high-brightness laser point cloud of the reflector 13.

[0041] The unmanned forklift 30 of this embodiment has the following advantages. (1) Even if a specific reflector 13 among the multiple reflectors 13 is not detected because the cargo W loaded and unloaded by the cargo handling device 33 blocks the laser light passing through the dead space Sd, the control device 43 estimates its own position based on the multiple reflectors 13 that can be detected excluding the specific reflector 13. Therefore, it is not necessary to provide a dedicated laser space for passing the laser light in addition to the storage space including the dead space Sd on the shelf 20. As a result, the space efficiency of the shelf 20 is improved, the height of the shelf 20 is reduced, and the number of components of the shelf 20 can be reduced, thereby reducing the manufacturing cost.

[0042] (2) When the laser light detecting a specific reflector 13 is blocked, the control device 43 estimates its own position based on the high-intensity laser point clouds of at least three reflectors 13 detectable by the laser sensor 50. Therefore, when the laser light to a specific reflector 13 among the multiple reflectors 13 is blocked, the control device 43 estimates its own position based on the high-intensity laser point clouds of at least three reflectors 13 detected by the laser sensor 50, thereby enabling the control device 43 to accurately estimate its own position.

[0043] (3) The laser sensor 50 is equipped with a sensor rotation unit 52 that enables laser light to be scanned around the entire circumference (360°) of the vehicle body 31. Therefore, even if the multiple reflectors 13 required for estimating the vehicle's own position are provided in different positions, the multiple reflectors 13 required for estimating the vehicle's own position can be detected more reliably.

[0044] (4) At a position where the unmanned forklift 30 faces the frontage of the shelf 20, a plurality of reflectors 13 are attached to the wall 11 so that the laser sensor 50 can detect at least four reflectors 13. Therefore, even if the load W blocks the laser light passing through the dead space Sd and a specific reflector 13 is not detected, the control device 43 can detect the high-intensity laser point clouds of at least three reflectors 13.

[0045] (5) A plurality of reflectors 13 are attached to the wall 11 so that three or more reflectors 13 can be detected at positions other than the frontage of the warehouse 10. Therefore, at positions other than the frontage of the warehouse 10, the control device 43 can detect the high-intensity laser point clouds of three or more reflectors 13, unless the load W is raised to a height that blocks the laser light.

[0046] (6) When a load W is moved in or out of the shelf 20 and blocks the laser light that detects a specific reflector 13, causing a shortage of multiple reflectors 13 that can be detected to estimate the vehicle's own position, if the laser sensor 50 cannot detect three or more reflectors 13 for some reason, the amount of rotation output from the encoder 46 is used as odometry information, and the control device 43 estimates the vehicle's own position based on the odometry information. Since the amount of rotation of the axle of the rear wheels 35 detected by the encoder 46 is used as odometry information, there is no need to add any equipment for estimating the vehicle's own position.

[0047] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.

[0048] In the above embodiment, the laser sensor includes a sensor rotation unit that can scan the entire circumference of the vehicle body with the laser light, but this is not limited to the above. The laser sensor may scan the laser light within a range of, for example, 270°, but may not necessarily scan the entire circumference with the laser light. In the above embodiment, when a specific high-luminance member among the multiple high-luminance members is not detected because the load blocks the laser light passing through the dead space, the self-location is estimated based on the laser points and odometry information of at least three high-luminance members, but this is not limited to this. For example, when the laser light to a specific high-luminance member among the multiple high-luminance members is blocked, the self-location may be estimated based only on the laser points of at least three high-luminance members that can be detected by the laser sensor. Also, when the laser light to a specific high-luminance member among the multiple high-luminance members is blocked, the self-location may be estimated based only on the odometry information. In the above embodiment, the laser sensor is provided so that the laser light passes through the dead space of the second-level storage unit of the shelf, but this is not limited to the above. The height of the laser sensor may be changed depending on the conditions of the automated guided vehicle. For example, the laser light may pass through the dead space of the first-level storage unit. In the above embodiment, the shelf is fixed to the floor surface (fixed shelf), but the present invention is not limited to this. The shelf may be a movable shelf that is movable relative to the floor surface. If the shelf is a movable shelf, no reflective material is provided on the movable shelf. In the above embodiment, the multiple reflective materials are installed only on the walls of the warehouse, but this is not limited to the above. If the shelves are fixed shelves, the reflective materials may be installed on the support columns or cross members of the shelves. Furthermore, the reflective materials may be installed on columns other than the walls of the warehouse or on fixed structures installed in the warehouse. In the above embodiment, an unmanned reach forklift is exemplified as an unmanned guided vehicle, but the present invention is not limited to this. The unmanned guided vehicle is not limited to a forklift and may be of any type or form as long as it is an unmanned guided vehicle that can travel autonomously and can load and unload cargo onto and from a shelf. [Explanation of symbols]

[0049] 10 Stacker Crane 10 Warehouse 11 (11A, 11B, 11C, 11D, 11E) Wall 13(13A, 13B, 13C, 13D, 13E, 13F, 13G) Reflective material 20 Shelves 24 Cargo storage area 30 Unmanned forklift (automated guided vehicle) 31 Body 33 Cargo handling equipment 35 Rear wheels (drive wheels) 38 Fork 43 Control device 46 Encoder 50 Laser Sensor 52 Sensor rotating part 53 Light transmitter / receiver E. Search Range L Laser light R Predetermined radius (search range) Sw Cargo space Sd Dead Space W load

Claims

1. The car body and A loading device is provided on the vehicle body and allows cargo to be loaded and unloaded from a cargo storage section of a shelf that stores cargo; a laser sensor provided on the vehicle body and configured to scan a predetermined area around the vehicle body with a laser beam; A control device that estimates a self-position based on a laser point detected by the laser sensor. The laser sensor is provided at a height such that the laser light passes through a dead space required for lifting a load set above a load space of the storage space of the load storage section from the shelf, The height of the laser sensor is the same as the height at which a plurality of high-luminance members are installed separately from the shelf, When a load being loaded or unloaded by the loading device passes through the dead space and blocks a laser light that detects a specific high-brightness component among the multiple high-brightness components, the control device estimates the vehicle's own position based on a plurality of detectable high-brightness components excluding the specific high-brightness component.

2. The automated guided vehicle according to claim 1, characterized in that the control device estimates its own position based on the laser points of at least three of the high-brightness components that can be detected by the laser sensor when the laser light detecting the specific high-brightness component is blocked.

3. A drive wheel provided on the vehicle body; an encoder for detecting an amount of rotation of the drive wheel; The automated guided vehicle according to claim 1, characterized in that, when a laser light for detecting the specific high-brightness component is blocked and there are insufficient high-brightness components that can be detected for estimating the vehicle's own position, the control device uses the amount of rotation output from the encoder as odometry information and estimates the vehicle's own position based on the odometry information.

4. 3. The automated guided vehicle according to claim 1, wherein the laser sensor includes a sensor rotating portion capable of scanning the entire periphery of the vehicle body with a laser beam.

Images