Transport vehicle and handling program

Abstract

To provide a transport vehicle capable of side-shifting a cargo loading unit while referring to the positional relationship of cargo with respect to the cargo loading unit.SOLUTION: A transport vehicle 1 includes: fork prongs 16; a side shift unit 19 that side-shifts the fork prongs 16; a point group acquisition unit 22 that acquires a point group by horizontally irradiating cargo loaded on the fork prongs 16 with a laser; an edge identification unit that identifies a position of an edge of the cargo on the basis of the acquired point group; a cargo position identification unit; and a side shift controller that controls a side shift amount of the side shift unit 19. The cargo position identification unit detects, on the basis of the identified position of the edge of the cargo, whether a positional relationship of the cargo with respect to the fork prongs 16 changes when the fork prongs 16 are side-shifted.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a carrier vehicle for transporting loads and a loading and unloading program.

Background Art

[0002] Conventionally, as shown in Patent Document 1, there is an unmanned carrier vehicle that autonomously travels and performs loading and unloading operations. The unmanned carrier vehicle disclosed in Patent Document 1 includes a fork, a lifting device for lifting and lowering the fork, and a laser scanner for detecting the position of the vehicle itself. The unmanned carrier vehicle is configured to move to a predetermined loading and unloading position while detecting its own position, and perform loading and unloading operations by lifting and lowering the fork. Further, the unmanned carrier vehicle disclosed in Patent Document 2 includes a side shift unit, and the side shift unit moves the backrest and the fork in the left-right direction.

[0003] By the way, when loading a load, there are times when the load must be loaded in a narrow space. At this time, before loading the load, the landing point of the load can be adjusted by side shifting by the side shift unit. However, in the case of a manned carrier vehicle, it is possible to visually recognize that the load has come into contact with surrounding objects, but in the case of an unmanned carrier vehicle, there is a problem that it cannot be detected.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] Therefore, the problem to be solved by the present invention is to provide a carrier vehicle capable of side shifting a load loading section while referring to the positional relationship of a load with respect to the load loading section.

Means for Solving the Problems

[0006] In order to solve the above problems, the carrier vehicle according to the present invention includes: a load loading part; a side shift part for side shifting the load loading part; a point cloud acquisition part that horizontally irradiates a load loaded on the load loading part with a laser to acquire a point cloud, and an edge identification part that identifies the position of the edge of the load based on the acquired point cloud; a load position identification part, and a side shift control part that controls the side shift amount of the side shift part, and is provided with: When the load loading part is side shifting, the load position identification part detects whether the positional relationship of the load with respect to the load loading part changes based on the position of the identified edge of the load.

[0007] Preferably, the above carrier vehicle further includes a side shift stop part, When the load loading part is side shifting, the side shift stop part stops the operation of the side shift part when it is detected that the positional relationship of the load with respect to the load loading part has changed.

[0008] Preferably, the above carrier vehicle When loading a load, the side shift control part side shifts the load loading part by the side shift part until it is detected that the positional relationship of the load with respect to the load loading part has changed.

[0009] Preferably, the above carrier vehicle further includes a distance calculation part, The point cloud acquisition part is arranged at a position where it can irradiate a laser on an object adjacent to the load loading position, The edge identification part further identifies the edge of the object based on the acquired point cloud, The distance calculation part calculates the left - right direction distance between the load and the object based on the positions of the identified edges of the load and the object, The side shift control part determines the side shift amount based on the calculated left - right direction distance between the load and the object.

[0010] The above-described transporter preferably The edge identification unit analyzes the acquired point cloud using a frequency distribution with the distance in the left-right direction as the axis, and identifies an interval with a frequency adjacent to a region substantially without a frequency as the position of the edge of the load in the left-right direction. In the present invention, "substantially without a frequency" means excluding the case where there is a frequency in a region where there is nothing due to noise or the like. The edge identification unit may analyze by deleting the frequency due to noise or the like or ignoring a small frequency by a known technique.

[0011] The above-described transporter preferably The edge identification unit analyzes the acquired point cloud using a frequency distribution with the distance in the front-rear direction as the axis, identifies the interval of the peak value in the upper region as the edge of the object, and identifies the interval of the peak value in the lower region as the position of the edge of the load.

[0012] The above-described transporter preferably When there is no distance in the left-right direction between the load and the object, the side shift control unit side-shifts the load-carrying part in the direction from the object to the load-carrying position.

[0013] The above-described transporter preferably The point cloud acquisition unit is arranged at a position where the load loaded on the load-carrying part and the load-carrying position can be irradiated with a laser.

[0014] The above-described transporter is, for example, a forklift, includes a backrest, The point cloud acquisition unit is provided on the backrest.

[0015] In order to solve the above problems, the handling program according to the present invention operates a computer as the above-described edge identification unit, the above-described load position identification unit, and the above-described side shift control unit.

Effect of the Invention

[0016] The carrier vehicle according to the present invention can perform side shift of the load-carrying part while referring to the positional relationship of the load with respect to the load-carrying part.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Embodiment for Carrying Out the Invention

[0018] Hereinafter, an embodiment of the carrier vehicle and the handling program of the present invention will be described with reference to the accompanying drawings. The double-headed arrow X in the drawings indicates the left-right direction, the double-headed arrow Y indicates the front-rear direction, and the double-headed arrow Z indicates the up-down direction.

[0019] FIG. 1 is a side view of the carrier vehicle 1 according to this embodiment, and FIG. 2 is a functional block diagram of the control unit 30. The carrier vehicle 1 according to this embodiment is an unmanned carrier vehicle that autonomously travels and performs handling, but this is merely an example, and the carrier vehicle 1 according to the present invention is not limited thereto. For example, the carrier vehicle 1 may be a carrier vehicle that can be used for both manned and unmanned operations.

[0020] As shown in FIGS. 1 and 2, the carrier vehicle 1 includes a plurality of wheels 10, a vehicle body 11, a drive unit 12, a laser scanner 13, left and right masts 14, a lift bracket 15, left and right forks 16, a lifting unit 17, a backrest 18, a side shift unit 19, left and right carriages 20, left and right reach legs 21, left and right 2D LiDAR sensors 22, left and right connecting parts 23, and a control unit 30. The carrier vehicle 1 is a reach-type forklift, but this is also merely an example, and the carrier vehicle 1 according to the present invention may be a counterbalanced forklift.

[0021] The vehicle body 11 is disposed on the wheels 10, and the drive unit 12 is disposed inside the vehicle body 11. The drive unit 12 is configured to rotate or stop the wheels 10.

[0022] The laser scanner 13 is disposed above the vehicle body 11 and rotates horizontally to irradiate a laser. Then, the laser scanner 13 identifies the current position of the transport vehicle 1 by identifying the position of the reflector disposed in the facility by scanning the reflected light of the laser.

[0023] The left and right masts 14 extend vertically and are disposed in front of the vehicle body 11. The lift bracket 15 has a finger bar for fixing the left and right forks 16 and is configured to be lifted and lowered along the left and right masts 14 by a lifting part 17. The left and right forks 16 correspond to the "load loading part" of the present invention. In this embodiment, the number of forks 16 is four, but it may be two or six and is not particularly limited. The transport vehicle 1 is provided with four forks 16, so that two pallets (loads) can be lifted simultaneously.

[0024] The backrest 18 is formed in a frame shape, extends vertically and horizontally, and is configured to receive the loaded load W1. Note that the backrest 18 shown in FIGS. 3 and 5 shows only the outer frame, and this outer frame is disposed outside the forks 16 in the left-right direction.

[0025] The side shift part 19 has an actuator and is configured to move the backrest 18 together with the forks 16 in the left-right direction by the actuator. Thereby, the side shift part 19 can adjust the left-right position of the forks 16 with respect to the fork insertion hole of the pallet or adjust the position where the load W1 is loaded. The actuator may be a hydraulic actuator or an electric actuator and is not particularly limited.

[0026] The left and right carriages 20 are respectively provided outside the left and right masts 14, and the left and right reach legs 21 extend forward from the vehicle body 11. Guides for guiding the carriages 20 are provided inside the left and right reach legs 21, and the masts 14 are moved to the forward position or the backward position together with the carriages 20 by a reach cylinder (not shown).

[0027] The two-dimensional LiDAR sensors 22 on the left and right are composed of laser scanners, which rotate horizontally while irradiating lasers, and scan the reflected light of the lasers so as to be able to obtain the distances to objects around the two-dimensional LiDAR sensor 22 as point clouds PG. The two-dimensional LiDAR sensor 22 corresponds to the "point cloud acquisition unit" of the present invention. The point cloud acquisition unit may be, for example, a three-dimensional LiDAR sensor or a three-dimensional ToF (Time of Flight) camera instead of the two-dimensional LiDAR sensor 22, and is not limited to the two-dimensional LiDAR sensor.

[0028] As shown in FIGS. 1 and 3, the left and right connecting parts 23 have a first end part 23a, an intermediate part 23b, and a second end part 23c.

[0029] The first end part 23a is fixed to the left and right ends of the backrest 18, and the intermediate part 23b extends obliquely backward from the first end part 23a to the backrest 18 in a plan view. The second end part 23c has a horizontal plane continuous with the intermediate part 23b, and supports the two-dimensional LiDAR sensor 22 by the horizontal plane.

[0030] The length of the intermediate part 23b is configured such that the two-dimensional LiDAR sensor 22 supported by the second end part 23c is located outside the side surface of the load loaded on the fork 16. That is, if the width of the backrest 18 is narrow and the load protrudes left and right more than the backrest 18, the length of the intermediate part 23b will be configured to be longer accordingly.

[0031] FIG. 4 is a plan view showing the laser irradiation range LE of the two-dimensional LiDAR sensor 22, and FIG. 5 is a perspective view showing the laser irradiation range LE of the two-dimensional LiDAR sensor 22. FIGS. 4 and 5 also show the load W1 loaded on the fork 16 and the load W2 loaded adjacent to the load loading position P in front thereof. The load loading position P is, for example, a predetermined loading position of a moving shelf included in the cargo handling plan, a predetermined loading position of the cargo bed of the truck T, etc.

[0032] As shown in FIGS. 4 and 5, the two-dimensional LiDAR sensor 22 is disposed at a position where it can horizontally irradiate a load W1 mounted on the fork 16 and a load loading position P with a laser. Then, the two-dimensional LiDAR sensor 22 irradiates the laser while rotating horizontally and receives the reflected light, thereby obtaining the distance to an object for each irradiation angle. This distance data is obtained as a point cloud PG.

[0033] FIG. 6A is a diagram showing a point cloud PG obtained by the left two-dimensional LiDAR sensor 22. The X-axis in FIGS. 6A and 6B indicates the distance in the left-right direction, the Y-axis in FIGS. 6A and 6C indicates the distance in the front-rear direction, and the intersection (origin) of the X-axis and the Y-axis indicates the position of the two-dimensional LiDAR sensor 22. Also, the point cloud PG in the attached drawings is an image diagram for showing an example of the point cloud PG to be obtained, and is not the actually obtained point cloud PG. As shown in FIG. 6A, the point cloud PG is obtained along the end face of the load W2 loaded adjacent to the load W1 loaded on the fork 16 and the load loading position P.

[0034] As shown in FIG. 1, the control unit 30 is disposed inside the vehicle body 11. The control unit 30 is configured by a computer having a storage device, an arithmetic unit, and a memory. The storage device stores a handling program that causes the computer to operate as an edge specifying unit 35, a load position specifying unit 37, and a side shift control unit 40 described below.

[0035] As shown in FIG. 2, the control unit 30 includes a storage unit 32, a travel control unit 34, an edge specifying unit 35, a distance calculation unit 36, a load position specifying unit 37, a lifting control unit 38, a side shift control unit 40, and a side shift stop unit 41.

[0036] The storage unit 32 stores a handling schedule, and the handling schedule includes the load loading position P. The storage unit 32 also includes the positions of the left and right two-dimensional LiDAR sensors 22 and the distance from the retracted position to the advanced position of the mast 14.

[0037] The travel control unit 34 is configured to control the drive unit 12, and causes the carrier vehicle 1 to travel to the load position P by referring to the load position P stored in the storage unit 32 and the current position acquired by the laser scanner 13.

[0038] As will be described later, the edge identification unit 35 analyzes the acquired point cloud PG using a frequency distribution with the distances in the front-rear and left-right directions as the X-axis and Y-axis respectively, and identifies an interval with a frequency adjacent to a region substantially without a frequency as the position of the edge of the load W1 or the surrounding object (for example, the load W2) in the left-right and front-rear directions. As described above, "substantially without a frequency" in the present invention means excluding the case where there is a frequency in a region with nothing due to noise or the like. The edge identification unit 35 may analyze by deleting the frequency due to noise or the like or ignoring a small frequency by a known technique. Hereinafter, the description of "substantially without a frequency" will be abbreviated as "without a frequency".

[0039] As will be described later, the distance calculation unit 36 calculates the distances in the left-right and front-rear directions between the load W1 and the object based on the positions of the edges of the load W1 and the object (for example, the load W2) in the left-right and front-rear directions identified by the edge identification unit 35.

[0040] The travel control unit 34 may calculate the forward distance required for unloading based on the distance D2 in the front-rear direction between the load W1 and the load W2 calculated by the distance calculation unit 36 and the distance from the retracted position to the advanced position of the mast 14, and cause the carrier vehicle 1 to advance based on the calculated distance.

[0041] The load position identification unit 37 identifies the positions of the edges of the load W1 (W3) in the left-right and front-rear directions identified by the edge identification unit 35 as the side position and the front position on either the left or right side of the load W1 (W3).

[0042] Further, the load position identification unit 37 calculates the position at the center in the left-right direction of the load W1 (W3) based on the side positions on the left and right of the identified load W1 (W3).

[0043] Furthermore, when the fork 16 is side-shifted by the side-shift unit 19, the load position specifying unit 37 detects a change in the positional relationship between the two-dimensional LiDAR sensor 22 and the load W1 based on the position of the edge of the specified load W1. Also, when the fork 16 is pulled out from the load W1 (W3), the load position specifying unit 37 detects a change in the positional relationship between the two-dimensional LiDAR sensor 22 and the load W1 (W3). Since the positional relationship between the two-dimensional LiDAR sensor 22 and the fork 16 is fixed, ultimately, the load position specifying unit 37 detects whether the positional relationship of the load W1 with respect to the fork 16 (load loading unit) changes.

[0044] The lifting control unit 38 is configured to control the lifting unit 17, and raises and lowers the fork 16 by the lifting unit 17 based on the load loading position P stored in the storage unit 32.

[0045] The side-shift control unit 40 is configured to control the side-shift amount of the side-shift unit 19. Then, the side-shift control unit 40 determines the side-shift amount of the side-shift unit 19 based on the left-right direction distance D1 between the load W1 specified by the distance calculation unit 36 and an object adjacent to the load loading position P.

[0046] Thereby, the side-shift control unit 40 moves the load W1 closer to or away from the object adjacent to the load loading position P. As a result, the side-shift control unit 40 can squeeze between the load W1 and the load W2 to load the load W1, or avoid a state where the load W1 overlaps.

[0047] Note that, as will be described later, if it is desired to press the load W1 against an object during load loading, the side-shift control unit 40 may side-shift the load loading unit by the side-shift unit 19 until a change in the positional relationship between the two-dimensional LiDAR sensor 22 and the load W1 is detected by the load position specifying unit 37.

[0048] When the fork 16 is undergoing side shift, if the load position specifying unit 37 detects a change in the positional relationship between the two-dimensional LiDAR sensor 22 and the load W1, the side shift stop unit 41 stops the operation of the side shift unit 19. As a result, when the load W1 contacts an object (e.g., load W2) adjacent to the load loading position P on the carrier vehicle 1, the lateral movement of the fork 16 by the side shift unit 19 stops, so that, for example, damage to the front panel of the truck T can be prevented.

[0049] <Edge Position Specifying Method and Distance Calculation Method> Next, a method in which the edge specifying unit 35 specifies the positions of the edges of the load W1 and the object, and the distance calculation unit 36 calculates the lateral distance D1 between the load W1 and the load W2 will be described again with reference to FIG. 6. FIGS. 6B and 6C show the point cloud PG of FIG. 6A as histograms in the lateral direction and the vertical direction. In this description, the explanation is based on the point cloud PG acquired by the left two-dimensional LiDAR sensor 22. Therefore, when implementing the edge position specifying method and the distance calculation method according to the present invention based on the point cloud PG acquired by the right two-dimensional LiDAR sensor 22, the left and right are reversed.

[0050] As shown in FIG. 6B, according to the frequency distribution on the X-axis, there is a region with no frequency in the center. This region indicates a region where the reflection of the laser by the two-dimensional LiDAR sensor 22 is extremely low or absent compared to other regions.

[0051] The edge specifying unit 35 specifies the right frequency interval S1 adjacent to the region with no frequency as the position (lateral coordinate) of the left edge of the load W1. Further, the edge specifying unit 35 specifies the left frequency interval S2 adjacent to the region with no frequency as the position (lateral coordinate) of the right edge of the load W2.

[0052] Further, as shown in FIG. 6C, according to the frequency distribution on the Y-axis, there are regions without frequencies that are closest to the origin and regions without frequencies that are second closest to the origin. These regions also indicate regions where the laser reflection by the two-dimensional LiDAR sensor 22 is extremely low or absent compared to other regions.

[0053] The edge identification unit 35 identifies the position (vertical coordinate) of the front edge of the load W1 as seen from the carrier vehicle 1 as the interval S3 with frequency adjacent to the upper side of the region without frequency closest to the origin. Further, the edge identification unit 35 identifies the position (vertical coordinate) of the front edge of the load W2 as the upper interval S4 with frequency adjacent to the region without frequency second closest to the origin.

[0054] Note that since each of the intervals S1, S2, S3, and S4 has a numerical width, the average value of the numerical values of each interval may be used as the position of each edge, or the minimum value or the maximum value in the interval S1 may be used as the position of each edge.

[0055] The distance calculation unit 36 calculates the distance D1 between the positions of the edges of the load W1 and the load W2 identified in the left-right direction, that is, the distance D1 between the coordinates of each edge in the left-right direction. Next, the distance calculation unit 36 calculates the distance D2 between the positions of the edges of the load W1 and the load W2 identified in the up-down direction, that is, the distance D2 between the coordinates of each edge in the up-down direction.

[0056] Incidentally, as shown in FIG. 6C, according to the frequency distribution on the Y-axis, peak values exist in the upper interval group and the lower interval group sandwiching the second region without frequency. Therefore, the edge identification unit 35 may identify the lower interval among these two peak value intervals as the position (vertical coordinate) of the front edge of the load W1 as seen from the carrier vehicle 1. Further, the edge identification unit 35 may identify the upper interval among these two peak value intervals as the position (vertical coordinate) of the front edge of the load W2.

[0057] In this way, the transport vehicle 1 can identify the position of the load W1 and the positions of the edges of each object adjacent to the load placement position P by analyzing the point cloud PG acquired by the two-dimensional LiDAR sensor 22 using the frequency distribution. Furthermore, the transport vehicle 1 can calculate the left-right distance D1 and the front-back distance D2 between the load W1 and the object adjacent to the load placement position P.

[0058] As a result, even if the mobile rack, the truck T, etc. are displaced from the predetermined position, the transport vehicle 1 can correct the load placement position P later, so that the load W1 can be loaded at an appropriate position. Note that the histograms in FIGS. 6B and 6C are for the purpose of explaining the frequency distribution in this specification, and it is not particularly necessary for the edge identification unit 35 to create a histogram.

[0059] FIGS. 7 to 10 show examples of information that can be obtained by frequency distribution analysis by the transport vehicle 1.

[0060] FIG. 7A shows the point cloud PG acquired by the two-dimensional LiDAR sensor 22 when the load placement position P is a frame-shaped rack. The left side of FIG. 7A shows two point clouds PG obtained by irradiating the two frames with laser light. FIGS. 7B and 7C show the acquired point cloud PG as histograms in the left-right direction and the up-down direction.

[0061] The edge identification unit 35 identifies the right-side frequency section S1 adjacent to the region without frequency as the position (left-right coordinate) of the left edge of the load W1 by the same method as described above. Also, the edge identification unit 35 identifies the left-side frequency section S2 adjacent to the region without frequency as the position (left-right coordinate) of the right edge of the frame.

[0062] Furthermore, the edge identification unit 35 identifies the position (vertical coordinate) of the front edge of the load W1 as seen from the carrier 1 as the upper frequency interval S3 adjacent to the region without frequency that is closest to the origin. Also, the edge identification unit 35 identifies the position (vertical coordinate) of the front edge of the frame as the upper frequency interval S4 adjacent to the region without frequency that is the second closest to the origin.

[0063] Next, the distance calculation unit 36 calculates the gap distance D1 between the positions of the edges of the identified load W1 and the edges of the load W2 in the left-right direction by the same method as described above. Also, the distance calculation unit 36 calculates the gap distance D2 between the position of the edge of the identified frame in the vertical direction and the position of the edge of the load W2.

[0064] Also, FIG. 8A shows the point cloud PG acquired by the 2D LiDAR sensor 22 when the position of the 2D LiDAR sensor 22 is arranged at the center of the height of the backrest 18. On the right side of FIG. 8A, the point cloud PG acquired by the reflection of the laser on the end of the backrest 18 is shown.

[0065] In this case, the edge identification unit 35 identifies the lower interval S5 as the position of the front edge of the load W1 as seen from the carrier 1 among the peak value intervals of the upper interval group and the lower interval group, and identifies the upper interval S6 as the position (vertical coordinate) of the front edge of the load W2. Note that the edge identification unit 35 identifies the positions of the edges of the loads W1 and W2 in the left-right direction by the same method.

[0066] Next, the distance calculation unit 36 calculates the gap distances D1 and D2 by the same method.

[0067] Also, FIG. 9A shows the point cloud PG acquired by the 2D LiDAR sensor 22 when there is an abnormality in the loading destination space such as load collapse. On the upper side of FIG. 9A, the point cloud PG acquired by the reflection of the laser on the abnormality occurrence location is shown.

[0068] In this case, as shown in Fig. 9B, there is no region without frequency in the center in the left-right direction. Therefore, the edge identification unit 35 cannot identify the edges of the load W1 and the load W2. In other words, the edge identification unit 35 can identify that there is no gap between the load W1 and the load W2. Thereby, it can be recognized that the handling of the load cannot be performed without interference between the loads, such as when there is an abnormality in the loading destination space. At this time, the control unit 30 may stop the handling operation of the carrier vehicle 1.

[0069] Note that there may be no abnormality in the loading destination space. Therefore, the side shift control unit 40 may be configured to side shift the load loading unit in the direction from the object to the load loading position P when there is no distance in the left-right direction between the load W1 and the object (load W2). The case where there is no distance in the left-right direction between the load W1 and the object (load W2) is, for example, the case where the load W1 and the load W2 overlap in the left-right direction.

[0070] Fig. 10A shows a point cloud PG obtained by irradiating only the load W1 with a laser by the 2D LiDAR sensor 22.

[0071] As shown in Figs. 10B and 10C, the edge identification unit 35 identifies the frequency intervals S7 and S8 closer to the origin as the positions of the left-right and up-down edges of the load W1.

[0072] Next, the distance calculation unit 36 calculates the distances D3 and D4 from the 2D LiDAR sensor 22 (origin) to the positions of the left side and the front side edges of the load W1 identified. Thereby, the positional relationship between the load W1 and the 2D LiDAR sensor 22 can be obtained.

[0073] As briefly described in the Background Art section, conventionally, in analysis using a LiDAR sensor, the distance between surrounding objects and the LiDAR sensor is specified by comparing and matching the shape and features of a pre-specified object with the acquired point cloud PG. In this method, when the unloading destination is a thin frame-shaped structure, when the surrounding structure including the backrest 18 is detected by the LiDAR sensor, or when there is an abnormality in the loading destination space, it is difficult to stably acquire the distance to the surrounding objects.

[0074] Also, in conventional analysis using a LiDAR sensor, since it is a method of recognizing the shape and features of a pre-specified object, the position of the LiDAR sensor is adjusted so that the load W1 is irradiated with a laser and the laser is not blocked. Therefore, with the conventional method, the mutual positional relationship between the transport vehicle 1, the load W1, and the objects adjacent to the load loading position P cannot be acquired only by the LiDAR sensor. Therefore, with the conventional method, it is necessary to separately perform other distance measurements, interference confirmation, etc., and for that purpose, it was necessary to separately arrange other sensors, etc.

[0075] On the other hand, according to the method of the present invention, by using only the two-dimensional LiDAR sensors 22 on the left and right, the mutual positional relationship between the transport vehicle 1, the loaded load W1, and the object or load W2 adjacent to the load loading position P can be acquired. Moreover, according to the method of the present invention, even when the unloading destination is a thin frame-shaped structure, or when the surrounding structure including the backrest 18 is detected by the two-dimensional LiDAR sensor 22, the distance between the load W1 and the load W2 can always be stably acquired. Furthermore, according to the method of the present invention, when there is an abnormality in the loading destination space, the cargo handling operation can be promptly stopped.

[0076] Next, with reference to FIGS. 11 and 12, an example of a series of operations of the transport vehicle 1 according to the present invention will be described. In this description, the transport vehicle 1 in FIGS. 11 and 12 is described as a counterbalanced forklift. Therefore, the position of the mast 14 in the front-rear direction is described as not moving.

[0077] (1)(1-1) As shown in Fig. 11A, before lifting the load W3, the transport vehicle 1 irradiates the load W3 with a laser by means of the left and right two-dimensional LiDAR sensors 22. (1-2) Next, the transport vehicle 1 analyzes the acquired point cloud PG by the edge identification unit 35 using the frequency distribution to identify the edge positions of the left and right ends of this load W3. (1-3) Next, the transport vehicle 1 calculates the position at the center in the left-right direction of the load W3 by the load position identification unit 37, and calculates the distance D5 between the position at the center in the left-right direction of the load W3 and the position at the center in the left-right direction of the backrest 18 by the distance calculation unit 36. (1-4) Further, based on the calculated distance D5, the transport vehicle 1 moves the fork 16 in the left-right direction by the side shift unit 19, thereby correcting the center deviation between the fork 16 and the load W3.

[0078] Note that, for example, when the transport vehicle 1 is a side fork vehicle, the transport vehicle 1 can correct the center deviation between the fork 16 and the load W3 by moving the vehicle body 11 by the travel control unit 34 based on the identified distance D5.

[0079] (2)(2-1) Next, the transport vehicle 1 lifts the load W3 (W1) and transports it to the truck T, and while irradiating the laser toward the loading platform of the truck T by the two-dimensional LiDAR sensor 22 on the truck T side as shown in Fig. 11B, travels parallel to the loading platform of the truck T. (2-2) Next, the transport vehicle 1 analyzes the acquired point cloud PG by the edge identification unit 35 using the frequency distribution to identify the position of the edge of the object (load W2) adjacent to the load loading position P on the loading platform, and calculates the mutual distances (positional relationships) between the identified edge position, the position of the two-dimensional LiDAR sensor 22, and the position of the load W1 by the distance calculation unit 36. (2-3) Next, when the transport vehicle 1 identifies the position of the edge of this object, it changes its direction toward the truck T side by the travel control unit 34 based on the positional relationship between the identified edge position, the position of the two-dimensional LiDAR sensor 22, and the load W1.

[0080] (3)(3-1) Next, as shown in FIG. 11C, before the carrier vehicle 1 moves forward toward the loading position P, it irradiates a laser horizontally with the two-dimensional LiDAR sensor 22. (3-2) Next, the carrier vehicle 1 analyzes the acquired point cloud PG using the frequency distribution by the edge identification unit 35 to identify the positions of the edges of the loads W1 and W2. (3-3) Next, the carrier vehicle 1 calculates the distance D1 between the loads W1 and W2 by the distance calculation unit 36 to determine whether the load W1 interferes with the load W2. At this time, as described above, when the carrier vehicle 1 identifies that an abnormality has occurred, it may stop the handling operation.

[0081] (4)(4-1) Next, the carrier vehicle 1 moves forward to the loading position P by the travel control unit 34 based on the front-rear direction distance D2 between the loads W1 and W2 calculated by the distance calculation unit 36. (4-2) Next, as shown in FIG. 12A, before lowering the load W1, the carrier vehicle 1 irradiates a laser horizontally with the two-dimensional LiDAR sensor 22. (4-3) Next, the carrier vehicle 1 analyzes the acquired point cloud PG using the frequency distribution by the edge identification unit 35 to identify the edges of the loads W1 and W2. (4-4) Next, the carrier vehicle 1 calculates the distance D1 between the loads W1 and W2 by the distance calculation unit 36. (4-5) Next, the carrier vehicle 1 determines an appropriate side shift amount by the side shift control unit 40 based on the calculated distance D1.

[0082] As a result, the carrier vehicle 1 can appropriately move the load W1 closer to the load W2 by the side shift unit 19.

[0083] (5)(5-1) Next, as shown in FIG. 12B, when the side shift unit 19 moves the fork 16 to the left, the carrier vehicle 1 irradiates a laser with the two-dimensional LiDAR sensor 22. (5-2) Next, while the transport vehicle 1 identifies the edge of the load W1 by the edge identification unit 35 and identifies the positional relationship between the two-dimensional LiDAR sensor 22 and the load W1 by the load position identification unit 37, the side shift unit 19 moves the fork 16. (5-3) At this time, when the transport vehicle 1 detects a change in the positional relationship between the two-dimensional LiDAR sensor 22 and the load W1 by the load position identification unit 37, the side shift stop unit 41 stops the operation of the side shift unit 19.

[0084] As a result, the transport vehicle 1 can detect that the load W1 starts to slide on the fork 16. Therefore, for example, the transport vehicle 1 can detect that the load W1 has been pressed against an object such as the front panel or the rear panel of the truck T, and after this detection, by stopping the movement of the fork 16, it can prevent damage to the front panel or the rear panel.

[0085] On the other hand, if the transport vehicle 1 wants to press the load W1 against the load W2, the side shift control unit 40 may cause the side shift unit 19 to side shift the load loading unit until it is detected that the load W1 starts to slide on the fork 16.

[0086] (6)(6-1) Next, as shown in FIG. 12C, when the transport vehicle 1 pulls out the fork 16 from the load W3, the two-dimensional LiDAR sensor 22 irradiates a laser. (6-2) Next, the transport vehicle 1 analyzes the acquired point cloud PG using the frequency distribution by the edge identification unit 35 to identify the edge of the load W3, and pulls out the fork 16 while the load position identification unit 37 identifies the positional relationship between the two-dimensional LiDAR sensor 22 and the load W3. (6-3) At this time, when the transport vehicle 1 detects that there is no change in the positional relationship between the two-dimensional LiDAR sensor 22 and the load W3 by the load position identification unit 37, the travel control unit 34 stops the movement of the transport vehicle 1.

[0087] As a result, the transport vehicle 1 prevents pulling the load W3 by the fork 16.

[0088] As described above, the two-dimensional LiDAR sensor 22 is disposed at a position where it can irradiate the load W1 and the load placement position P with a laser. Thus, the load W1 and an object adjacent to the load placement position P (for example, the load W2) can be irradiated with the laser, and the reflected light from the load W1 and the object adjacent to the load placement position P can be detected to obtain the point group PG. As a result, the transport vehicle 1 can specify the positions of the edges of the load W1 and the load W2 by the edge specifying unit 35, and can calculate the distances D1 and D2 by the distance calculating unit 36. Therefore, even if a movable shelf, a truck T, or the like is displaced from a predetermined position, the load placement position P can be corrected later, and the loading and unloading work can be appropriately performed.

[0089] Moreover, since the transport vehicle 1 detects whether or not the positional relationship of the load W1 with respect to the fork 16 changes by the load position specifying unit 37, it is possible to detect that the load W1 has come into contact with a surrounding object.

[0090] In addition, the transport vehicle 1 can specify the three relative positional relationships among the load W1, the load W2, and the two-dimensional LiDAR sensor 22 (transport vehicle 1) by analyzing the point group PG using the frequency distribution. Therefore, the series of operations (1) to (6) described above can be performed.

[0091] As described above, one embodiment of the transport vehicle and the loading and unloading program according to the present invention has been described. However, the present invention is not limited to the above embodiment. For example, the transport vehicle according to the present invention may be implemented by the following modification examples.

[0092] <Modification Example> · The second end portion 23c of the connecting portion 23 may not be located above the backrest 18. In this case, the point group PG acquired by the two-dimensional LiDAR sensor 22 becomes the point group PG shown in FIG. 8A. However, as already described, the edge specifying unit 35 can specify the positions of the edges of the loads W1 and W2, and the distance calculating unit 36 can calculate the distance between the loads W1 and W2. Further, the first end portion 23a of the connecting portion 23 may be provided at the upper end of the backrest 18.

[0093] · If the two-dimensional LiDAR sensor 22 is arranged at a position where it can irradiate a laser beam, for example, on the load W1 loaded on the load-carrying part 16 and an object adjacent to the load-carrying position P, it may be fixed to the vehicle body 11, the finger bar, or the first end 23a of the connecting part 23 may be fixed to the side surface (see FIG. 1) of the vertically extending part 16a of the fork 16 in the vertical direction. Alternatively, the two-dimensional LiDAR sensor 22 may be fixed to the vehicle body 11, the vertically extending part 16a of the fork 16, or the finger bar via the connecting part.

[0094] · The load-carrying part may be constituted by a platen, for example, instead of the fork 16.

Explanation of Reference Numerals

[0095] W1 Load loaded on the load-carrying part W2 Load loaded adjacent to the load-carrying position W3 Load loaded at the load-carrying position D1 Distance in the left-right direction D2 Distance in the front-rear direction P Load-carrying position LE Laser irradiation range PG Point cloud T Truck 1 Conveyor vehicle 10 Wheels 11 Vehicle body 12 Driving part 13 Laser scanner 14 Mast 15 Lift bracket 16 Fork (load-carrying part) 16a Vertically extending part 17 Lifting part 18 Backrest 19 Side shift part 20 Carriage 21 Reach leg 22 Two-dimensional LiDAR sensor (point cloud acquisition part) 23 Connecting part 23a First end 23b Intermediate part 23c Second End 30 Control Unit 32 Memory Unit 34 Travel Control Unit 35 Edge Identification Unit 36 Distance Calculation Unit 37 Load Position Identification Unit 38 Lifting Control Unit 40 Side Shift Control Unit 41 Side Shift Stop Unit

Claims

1. a load carrying part, a side shift part for side shifting the load carrying part, a point cloud acquisition part whose positional relationship with respect to the load carrying part is fixed, and which irradiates only horizontally the load loaded on the load carrying part with a laser to acquire a horizontal point cloud, an edge identification part capable of identifying the position of the edge of the load based only on the horizontal point cloud acquired by one laser scanner, a load position identification part, and a side shift control part for controlling the side shift amount of the side shift part, the point cloud acquisition part is composed of one laser scanner on either the left or right, or one laser scanner on each of the left and right, the load position identification part detects whether or not the positional relationship of the load with respect to the load carrying part changes based on the position of the edge of the load identified by the edge identification part when the load carrying part is side shifting, a transport vehicle.

2. A load carrying part, a side shift part for side shifting the load carrying part, a point cloud acquisition part that irradiates the load loaded on the load carrying part horizontally with a laser to acquire a point cloud, an edge identification part that identifies the position of the edge of the load based on the acquired point cloud, a load position identification part, a side shift control part for controlling the side shift amount of the side shift part, and a side shift stop part, the load position identification part detects whether or not the positional relationship of the load with respect to the load carrying part changes based on the position of the edge of the load identified when the load carrying part is side shifting, the side shift stop part stops the operation of the side shift part when it is detected that the positional relationship of the load with respect to the load carrying part changes while the load carrying part is side shifting, a transport vehicle.

3. A load carrying part, A side shift unit that side-shifts the load-carrying part, A point cloud acquisition unit that irradiates a load placed on the load-carrying part with a laser horizontally to acquire a point cloud, An edge identification unit that identifies the position of the edge of the load based on the acquired point cloud, A load position identification unit, A side shift control unit that controls the side shift amount of the side shift unit, and includes a transport vehicle that side-shifts the load-carrying part by the side shift unit until it is detected that the positional relationship of the load with respect to the load-carrying part changes during load loading. When the load-carrying part is side-shifting, the load position identification unit detects whether the positional relationship of the load with respect to the load-carrying part changes based on the position of the identified edge of the load. The side shift control unit side-shifts the load-carrying part by the side shift unit until it is detected that the positional relationship of the load with respect to the load-carrying part changes during load loading.

4. A load-carrying part, A side shift unit that side-shifts the load-carrying part, A point cloud acquisition unit that irradiates a load placed on the load-carrying part with a laser horizontally to acquire a point cloud, An edge identification unit that identifies the position of the edge of the load based on the acquired point cloud, A load position identification unit, A side shift control unit that controls the side shift amount of the side shift unit, A distance calculation unit, and includes: The load position identification unit is configured to detect whether the positional relationship of the load with respect to the load-carrying part changes based on the position of the identified edge of the load when the load-carrying part is side-shifting. The point cloud acquisition unit is arranged at a position where it can irradiate a laser even on an object adjacent to the load loading position. The edge identification unit further identifies the edge of the object based on the acquired point cloud. The distance calculation unit calculates the left-right direction distance between the load and the object based on the positions of the identified edges of the load and the object. The side shift control unit determines the side shift amount based on the calculated horizontal distance between the load and the object, the transport vehicle. **Claim 5** The edge identification unit analyzes the acquired point cloud using a frequency distribution with the horizontal distance as the axis, and identifies an interval with frequency adjacent to a region without substantial frequency as the position of the edge of the load in the horizontal direction, the transport vehicle according to claim 4. **Claim 6** The edge identification unit analyzes the acquired point cloud using a frequency distribution with the front-rear distance as the axis, identifies an interval of the peak value in the upper region as the edge of the object, and at the same time identifies an interval of the peak value in the lower region as the position of the edge of the load, the transport vehicle according to claim 5. **Claim 7** When there is no horizontal distance between the load and the object, the side shift control unit side-shifts the load-carrying part in the direction from the object to the load-carrying position, the transport vehicle according to claim 4. **Claim 8** The point cloud acquisition unit is arranged at a position where the load loaded on the load-carrying part and the load-carrying position can be irradiated with a laser, the transport vehicle according to claim 1. **Claim 9** The transport vehicle is a forklift and includes a backrest, The point cloud acquisition unit is provided on the backrest, the transport vehicle according to claim 1. **Claim 10** A cargo handling program that causes a computer to operate as the edge identification unit, the load position identification unit, and the side shift control unit of claim 1.

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