Position determination system, transport vehicle, position determination method, and storage medium

Abstract

The invention provides a position determination system, a transport vehicle, a position determination method, and a storage medium, for determining an edge position on an X-axis coordinate of an object adjacent to a loading space in a relatively simple and versatile manner in order to determine a loading / unloading position on the X-axis coordinate. A position determination system is provided with: a point group acquisition unit (22) that acquires a point group (PG) by horizontally irradiating light onto a space on a cargo box (Ta); an analysis unit; and a position determination unit. The analysis unit analyzes the acquired point group (PG) using a degree distribution with the distance in the X-axis direction as the axis. On the basis of the analysis result of the point group (PG), the position specifying unit specifies a region (D2) having substantially no degree as a loading space, and specifies sections (S1, S2) adjacent to the loading space and having a degree equal to or greater than a predetermined degree as the position of the edge of an object adjacent to the loading space on the X-axis coordinate.

Description

Technical Field

[0001] The present invention relates to a position determination system for determining the position of an edge of an object at a loading and unloading position of a transport vehicle, a transport vehicle, a position determination method, and a storage medium. Background Art

[0002] As disclosed in Patent Document 1, an unmanned guided vehicle (AGV) is known that autonomously travels and performs loading and unloading operations. This AGV includes a fork, a lifting device that raises and lowers the fork, and a laser scanner that detects the vehicle's position. The AGV is configured to move to a predetermined loading and unloading position while detecting the vehicle's position, then raise and lower the fork to perform loading and unloading operations.

[0003] Let's say, Figure 10 A. Figure 10 As shown in Figure B, this type of automated guided vehicle 100 sometimes performs loading and unloading operations on the cargo box Ta of a truck T. However, unlike fixed cargo racks, trucks T may not stop at a predetermined location. Therefore, the automated guided vehicle 100 cannot predetermine the loading and unloading locations. In addition, the length of the cargo box Ta of a truck T varies depending on the vehicle model. Therefore, even if the truck T stops at a predetermined location, the loading and unloading location will vary for each truck T. Furthermore, in order to effectively utilize the cargo box Ta of a truck T, the cargo L must be fully loaded. Therefore, if the location of the cargo L previously accumulated in the cargo box Ta is not determined, it is impossible to determine the location of the next cargo L to be placed.

[0004] Therefore, for example, there is an unmanned guided vehicle (forklift) as disclosed in Document 2. The unmanned guided vehicle includes an external sensor that detects the position of an object using coordinates in a three-dimensional coordinate system, (1) extracts points representing a horizontal plane from a set of points representing the position of the object, i.e., point group data, (2) extracts points within a predetermined range in the vertical direction from the horizontal plane as points representing a cargo box, and (3) extracts points representing the edge of the cargo box from the points representing the cargo box. Furthermore, the unmanned guided vehicle is configured to: (4) detect a straight line representing an edge from the points representing the edge, (5) extract a point that is at least a predetermined distance above the horizontal plane as a point representing a load loaded in the cargo box, and (6) detects a position that is a predetermined distance away from the load in the extension direction of the straight line as a stacking position for stacking the cargo in the cargo box.

[0005] However, object detection (extraction) methods using this type of point cloud data involve processes such as clustering (dividing multiple point clusters into specific sets) and pattern matching (for example, extracting straight lines). These methods require high precision (high resolution of the point cloud data), necessitating the use of computers with high data processing capabilities. Furthermore, these methods require adjustments to the detection algorithm and pattern for each object, making them difficult to apply universally.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2020-030642

[0009] [Patent Document 2] Japanese Patent Application Laid-Open No. 2023-030983 Summary of the Invention

[0010] [Problems to be solved by the invention]

[0011] Let's say, Figure 10 As shown in A, the truck T to be loaded and unloaded is usually parked in the parking area SE in a specified direction. In addition, the width W of the cargo L can also be set to the width of a specified pallet on which the cargo is placed. Therefore, if the edge position Ex on the X axis of an object (for example, cargo L) adjacent to the loading space can be determined, the position separated from the edge position Ex by half the width W in the opposite direction of the object can be determined as the loading and unloading position LPx of the X axis coordinate during loading. In addition, as Figure 10 As shown in FIG. 1B, if the edge position Ex of the cargo L placed on the cargo box Ta on the X axis can be determined, the distance from the edge position Ex toward the center of the cargo L, which is half the width W, can be determined as the loading and unloading position LPx of the X axis coordinate when unloading. Figure 10 A. Figure 10 Although the width W of the cargo L is set to the width of the pallet in the description of B, the width W of the cargo L does not necessarily have to be the same as the pallet. For example, even if the width W of the cargo L is longer or shorter than the pallet width, the loading and unloading position LPx can be determined if the width W of the cargo L is known or falls within a predetermined range.

[0012] Therefore, the problem to be solved by the present invention is to provide a positioning system that can relatively simply and universally determine the edge position of an object adjacent to a loading space on the X-axis coordinate in order to determine the loading and unloading position on the X-axis coordinate.

[0013] [Technical means to solve the problem]

[0014] In order to solve the above-mentioned problem, the position determination system of the present invention is used for a transport vehicle, and the position determination system includes:

[0015] The point cloud acquisition unit horizontally illuminates the loading space to acquire a point cloud; the analysis unit analyzes the acquired point cloud using a degree distribution with distance in the X-axis direction as the axis; and the position determination unit, based on the point cloud analysis results, determines an area with substantially no degree as the loading space, and determines an area adjacent to the loading space with a degree greater than a specified value as the edge of the object adjacent to the loading space on the X-axis coordinate. The term "horizontal" in the present invention also includes angles that are not perpendicular to the direction of gravity, such as when the ground has a gradient.

[0016] The position determination system is preferably:

[0017] The position determination unit includes the position of the point cloud acquisition unit only in an area with substantially no degree on the X-axis and when there are intervals with a degree greater than a specified degree on both sides of the area with substantially no degree at this time, the interval is determined as the position of the edge on the X-axis coordinate of the object adjacent to the loading space.

[0018] The position determination system is preferably:

[0019] The system further includes a loading and unloading target determination unit configured to determine an object adjacent to the loading space as an unloading target.

[0020] The position determination system is preferably:

[0021] The position identifying unit does not identify an area smaller than a predetermined distance in an area having substantially no degree on the X-axis as a loading space.

[0022] The position determination system is preferably:

[0023] The point cloud acquisition unit irradiates light horizontally to a surrounding space including the loading space and being wider than the loading space in the horizontal direction.

[0024] The position determination system is preferably:

[0025] The position determination unit determines an area with substantially no degree, which is adjacent to the center side of the loading space of the endmost area among multiple areas with degrees on the X-axis, as a loading space, and determines the position of another interval with a degree greater than a specified degree, which is adjacent to the determined loading space on the X-axis, as a position involved in the loading and unloading position of the transport vehicle.

[0026] The position determination system is preferably:

[0027] The position determination unit determines an area with substantially no degree adjacent to the center side of the loading space of the endmost area among multiple areas with degrees on the X-axis as a loading space, and determines the position of the interval with a degree greater than a specified value in the endmost area as a position related to the loading and unloading position of the transport vehicle.

[0028] In order to solve the above-mentioned problems, a transport vehicle according to the present invention includes any one of the above-mentioned position determining systems.

[0029] In order to solve the above-mentioned problem, the position determination method of the present invention is used for a transport vehicle, and the position determination method includes:

[0030] A point group is acquired by horizontally irradiating light onto the loading space through a point group acquisition unit; the acquired point group is analyzed using a degree distribution with distance in the X-axis direction as the axis; based on the analysis results of the point group, an area with substantially no degree is determined as the loading space; and an interval adjacent to the loading space with a degree greater than a specified value is determined as the position of an edge on the X-axis coordinate of an object adjacent to the loading space.

[0031] The position determination method is preferably:

[0032] When the position of the point cloud acquisition unit is included only in an area with substantially no degree on the X-axis and when there are intervals with a degree greater than a specified degree on both sides of the area with substantially no degree at this time, the interval is determined as the position of the edge of the object adjacent to the loading space on the X-axis.

[0033] The position determination method is preferably:

[0034] It also includes determining objects adjacent to the loading space as unloading targets.

[0035] The position determination method is preferably:

[0036] In the region with substantially no degree on the X-axis, a region smaller than a predetermined distance is not determined as a loading space.

[0037] The position determination method is preferably:

[0038] Light is irradiated horizontally to the surrounding space including the loading space, which is wider than the loading space in the horizontal direction, to obtain a point group.

[0039] An area with substantially no degree of latitude adjacent to the center of the loading space of the endmost area among the multiple areas with degree of latitude on the X-axis is determined as the loading space.

[0040] The position of another section having a predetermined angle or greater, adjacent to the determined loading space on the X-axis, is determined as a position related to the loading and unloading position of the transport vehicle.

[0041] The position determination method is preferably:

[0042] Light is irradiated horizontally to the surrounding space including the loading space, which is wider than the loading space in the horizontal direction, to obtain a point group.

[0043] An area with substantially no degree of latitude adjacent to the center of the loading space of the endmost area among the multiple areas with degree of latitude on the X-axis is determined as the loading space.

[0044] The position of a section having a predetermined degree or higher in the area at the end is determined as a position related to the loading and unloading position of the transport vehicle.

[0045] In order to solve the above-mentioned problem, a position determination program of the present invention is a program for a transport vehicle, the transport vehicle including a point cloud acquisition unit for horizontally irradiating light onto a loading space to acquire a point cloud, and

[0046] computer,

[0047] The position determination program causes the computer to execute

[0048] The obtained point group is analyzed using the degree distribution with the distance in the X-axis direction as the axis;

[0049] Based on the analysis results of the point group, determining an area with substantially no degree as a loading space; and

[0050] A section adjacent to the cargo space having a degree greater than or equal to a predetermined value is determined as the position of an edge of the object adjacent to the cargo space on the X-axis coordinate.

[0051] [Effects of the Invention]

[0052] The position determination system of the present invention can determine the edge position of an object adjacent to a loading space on the X-axis coordinate in a relatively simple and universal manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a plan view showing a truck and an automated guided vehicle according to one embodiment of the present invention.

[0054] Figure 2 Yes Figure 1 A side view of an automated guided vehicle is shown.

[0055] Figure 3 This is a block diagram of an unmanned guided vehicle.

[0056] Figure 4 A~ Figure 4 C represents Figure 2 The connecting portion shown, Figure 4 A is a three-dimensional view viewed from the back. Figure 4 B is a planar graph, Figure 4 C is the back view.

[0057] Figure 5 A is a plan view showing the laser irradiation of the two-dimensional LiDAR sensor on the right. Figure 5 B is a diagram showing a point group acquired by the two-dimensional LiDAR sensor on the right. Figure 5 The C stands for Figure 5 The point group of B is masked within a specified range. Figure 5 D is represented by a histogram in the X-axis direction Figure 5 The graph of the point group of C.

[0058] Figure 6 A represents the point cloud data obtained at the rear of the truck. Figure 6 B represents point cloud data obtained on one side of the truck cab.

[0059] Figure 7 A is a plan view of a cargo box equipped with maintenance materials and pallets. Figure 7 B represents the two-dimensional LiDAR sensor on the right. Figure 7 The graph of the point group obtained by A's cargo box, Figure 7 C is represented by a histogram in the X-axis direction Figure 7 The graph of the point group of B.

[0060] Figure 8 A is a plan view showing a container equipped with cylindrical components. Figure 8 B represents the two-dimensional LiDAR sensor on the right. Figure 8 The graph of the point group obtained by A's cargo box, Figure 8 C is represented by a histogram in the X-axis direction Figure 8 The graph of the point group of B.

[0061] Figure 9 This is a flowchart showing the flow of operations of the automated guided vehicle.

[0062] Figure 10 A. Figure 10 B is a plan view showing a conventional automated guided vehicle and a truck container.

[0063] [Explanation of Symbols]

[0064] L: cargo

[0065] LE: Laser irradiation range

[0066] LPx: loading and unloading position

[0067] P: Pallet

[0068] PG: Point Group

[0069] PM: Maintenance material

[0070] ROI: Region of Interest

[0071] RM: Cylindrical member

[0072] SE: Parking area

[0073] T: Truck

[0074] Ta:Cargo box

[0075] WL: White Line

[0076] W: Cargo width

[0077] 1: Transport vehicle

[0078] 10: Wheel

[0079] 11: Car body

[0080] 12: Drive unit

[0081] 13: Laser Scanner

[0082] 14: Mast

[0083] 15: Lifting bracket

[0084] 16: Fork

[0085] 17: Lifting unit

[0086] 18: Backrest

[0087] 22: 2D LiDAR sensor (point cloud acquisition unit)

[0088] 23: Connection

[0089] 23a: First end

[0090] 23b: Middle part

[0091] 23c: Second end

[0092] 30: Control Department

[0093] 301: Storage

[0094] 302: Local location identification unit

[0095] 303: Analysis Department

[0096] 305: Position determination unit

[0097] 306: Loading and unloading object determination unit

[0098] 307: Loading and unloading position determination unit

[0099] 308: Driving control unit

[0100] 309: Lifting control unit DETAILED DESCRIPTION

[0101] The double arrow X in the figure indicates the front-back direction (X axis), the double arrow Y indicates the left-right direction, and the double arrow Z indicates the up-down direction.

[0102] Figure 1 FIG. 1 is a plan view showing a truck T and a transport vehicle 1 according to the present embodiment. Figure 1 As shown, a truck T has a cargo box Ta at its rear and is parked in a parking area SE surrounded by white lines WL. The space above the cargo box Ta corresponds to the "loading space" of the present invention, and the space above the parking area SE corresponds to the "surrounding space" of the present invention. However, these are merely examples, and the location for loading and unloading in the present invention is not limited to the cargo box Ta of the truck T. For example, if loading and unloading occurs on a cargo rack or container, the space above the cargo rack or container corresponds to the "loading space" of the present invention, and the space surrounding the cargo rack or container corresponds to the "surrounding space" of the present invention.

[0103] In this embodiment, the transport vehicle 1 is configured to acquire a point group PG while traveling on the left and right sides of the truck T, from behind the truck T toward the front, and perform loading and unloading operations at a loading and unloading position LPx determined based on the acquired point group PG. In this embodiment, the transport vehicle 1 is configured to load cargo from the space in front of the cargo box Ta during loading, and to unload cargo from the rear of the multiple cargo items L loaded in the cargo box Ta during unloading. The transport vehicle 1 in this embodiment is an unmanned transport vehicle that autonomously travels and loads and unloads, but this is merely an example, and the transport vehicle of the present invention is not limited to this. For example, the transport vehicle of the present invention may also be a transport vehicle that can be used for both manned and unmanned transportation.

[0104] <Transporter Vehicle Structure>

[0105] Figure 2 is a side view of the transport vehicle 1. Figure 3 This is a block diagram of the transport vehicle 1. Figure 2 as well as Figure 3As shown, the transport 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, left and right two-dimensional LiDAR (Light Detection and Ranging) sensors 22, left and right connecting units 23, and a control unit 30. The transport vehicle 1 is a reach forklift, but this is merely an example; the transport vehicle 1 of the present invention may also be a counter-forklift.

[0106] The vehicle body 11 is disposed on the wheel 10, and the driving unit 12 is disposed inside the vehicle body 11. The driving unit 12 is configured to rotate or stop the wheel 10.

[0107] The laser scanner 13 is disposed above the vehicle body 11 , irradiates laser light while rotating horizontally, and scans reflected light of the laser light.

[0108] Left and right masts 14 extend vertically and are positioned at the rear of the vehicle body 11. A lifting bracket 15 includes fingers to which left and right forks 16 are fixed, and is raised and lowered along the left and right masts 14 by a lifting unit 17. In this embodiment, the number of forks 16 is four, but the number may be two or six, and is not particularly limited.

[0109] The backrest 18 is formed in a frame shape and extends vertically and horizontally to receive the loaded cargo L. Figure 4 A~ Figure 4 In FIG. 1C , only the outer frame of the seat back 18 is shown in the figure, and the outer frame is arranged further outward in the left-right direction than the vehicle body 11 .

[0110] The left and right 2D LiDAR sensors 22 are configured as laser scanners. They radiate laser light while rotating horizontally, scanning the reflected laser light to acquire the distance to the laser-irradiated object in the form of a point group PG. The 2D LiDAR sensors 22 correspond to the "point group acquisition unit" of this invention. The point group acquisition unit of this invention can be, for example, a 3D LiDAR sensor or a 3D Time of Flight (ToF) camera instead of the 2D LiDAR sensors 22, but is not limited to 2D LiDAR sensors. As such, "light" in this invention includes not only visible light but also invisible light.

[0111] Figure 4 A~ Figure 4 C represents the connecting portion 23, Figure 4 A is a perspective view viewed from above on the back side (fork 16 side), Figure 4 B is a planar graph, Figure 4C is a rear view. The connecting portion 23 has a first end portion 23a, a middle portion 23b, and a second end portion 23c. The first end portion 23a is fixed to the left and right ends of the backrest 18, and the middle portion 23b extends from the first end portion 23a to the oblique front of the backrest 18 when viewed from above. The second end portion 23c has a horizontal surface that is continuous from the middle portion 23b, and the two-dimensional LiDAR sensor 22 is supported by the horizontal surface. The position of the second end portion 23c is configured to be arranged at a position further to the left and right outside than the cargo L loaded on the fork 16 and the side of the vehicle body 11. As a result, the laser of the two-dimensional LiDAR sensor 22 is not blocked by the loaded cargo L or the vehicle body 11, but is irradiated toward the parking area SE including the cargo box Ta.

[0112] Figure 5 A represents an example of the irradiation range LE of the laser of the two-dimensional LiDAR sensor 22 and indicates the traveling direction of the transport vehicle 1. In addition, the irradiation range LE of the laser is not limited to the above range, and the laser may be irradiated to reach the entire range of the parking area SE. Figure 5 As shown in A, the transport vehicle 1 travels from the rear to the front on one side of the truck T, and the two-dimensional LiDAR sensor 22 irradiates laser light while rotating horizontally and receives reflected light, thereby obtaining the distance to the object at each irradiation angle. Figure 5 As shown in B, the distance data is obtained as a point group PG. Figure 5 The intersection of the X and Y axes in B represents the origin X0, that is, the position of the two-dimensional LiDAR. Note that the point group PG in the drawings is an image diagram showing an example of the acquired point group PG, and is not the point group PG actually acquired.

[0113] In the present invention, the point cloud PG can be acquired by the two-dimensional LiDAR sensor 22 while the transport vehicle 1 is stopped. The transport vehicle 1 does not necessarily need to travel parallel to the truck T in order to acquire the point cloud PG.

[0114] If the absolute position coordinates of the transport vehicle 1 can be recognized by known techniques, the absolute position coordinates of the two-dimensional LiDAR sensor 22 can also be determined, and the position of the acquired point group PG can also be determined on the absolute coordinate axis. Figure 5 B is also a diagram showing the point group PG shown on the absolute coordinate axis and the current positional relationship of the transport vehicle 1 relative to the point group PG.

[0115] like Figure 2 As shown, the control unit 30 is disposed inside the vehicle body 11. The control unit 30 includes a computer having a storage device, a computing unit, and a memory. The storage device stores a position determination program for causing the computer to execute the edge position determination method.

[0116] Functional structure of the control unit

[0117] Next, the functional structure of the control unit 30 will be described. Figure 3 As shown, the control unit 30 includes a storage unit 301, an aircraft position recognition unit 302, an analysis unit 303, a position determination unit 305, a loading / unloading target determination unit 306, a loading / unloading position determination unit 307, a travel control unit 308, and a lift control unit 309. The system including the two-dimensional LiDAR sensor 22 (point cloud acquisition unit), the analysis unit 303, the position determination unit 305, and the loading / unloading target determination unit 306 corresponds to the "position determination system" of the present invention.

[0118] The storage unit 301 stores the position (X coordinate, Y coordinate) of the parking area SE, the front and rear directions of the parked truck T, the width W of the cargo L, and the height to raise the fork 16 during loading and unloading.

[0119] The local position recognition unit 302 detects the position of a reflector disposed in the facility based on the reflected light scanned by the laser scanner 13 , thereby recognizing the current position of the transport vehicle 1 .

[0120] The analysis unit 303 analyzes the obtained point group PG using the degree distribution with the distance in the X-axis direction as the axis. Figure 5 As shown in C, the analysis unit 303 first defines the point group PG obtained as Figure 5 A~ Figure 5 The range indicated by the dotted line in D is the point group PG within the region of interest (ROI). Thus, the analysis unit 303 excludes unnecessary point groups PG. Figure 5 As shown in D, the analysis unit 303 analyzes the point group PG within the ROI using the degree distribution based on the distance in the X-axis direction from the origin X0 on the X-axis (front-back direction).

[0121] Figure 5 The region D2 with no intensity in D represents an area where the reflection of laser light from the two-dimensional LiDAR sensor 22 is extremely low or absent compared to other areas. The term "substantially no intensity" in this invention refers to areas where there is no intensity due to noise, etc. The analysis unit 303 can perform analysis by using known techniques to delete intensity caused by noise, etc., or to ignore low intensity. Hereinafter, the phrase "substantially no intensity" will be abbreviated as "no intensity."

[0122] Furthermore, since each interval has a numerical width, the average value of the numerical values of each interval can be used as the position (X coordinate) of the interval, or the minimum value or maximum value in each interval can be used as the position (X coordinate) of each interval.

[0123] The position determination unit 305 is based on the analysis result of the point group PG, such as Figure 5 As shown in D, area D2 with no intensity is determined as the loading space, and sections S1 and S2 adjacent to the loading space with an intensity greater than a predetermined value are determined as the edges of the object adjacent to the loading space on the X-axis coordinate. By forming "an intensity greater than a predetermined value," the position determination unit 305 can appropriately determine the sections within the sections of areas D1 and D3 with intensity that are the edges of the object on the X-axis. The minimum intensity for edge determination is appropriately set in advance to ensure that while determining the sections of the object's edge, sections other than the predetermined value are not mistakenly identified as edge sections.

[0124] The position determination unit 305 preferably includes the position of the two-dimensional LiDAR sensor 22 (origin X0) only in the area D2 with no degree on the X-axis, and when there are intervals S1 and intervals S2 with degrees above the specified value on both sides of the area D2 with no degree at this time, the intervals S1 and intervals S2 are determined as the positions of the edges on the X-axis coordinates of the object adjacent to the loading space.

[0125] This prevents the position determination unit 305 from misidentifying a simple space as a loading space. For example, if the parking area SE is sufficiently longer than the total length of the truck T, it is assumed that there is space in front of and behind the parked truck T. Furthermore, the two-dimensional LiDAR sensor 22 does not acquire the point cloud PG from the space above this space. Therefore, the position determination unit 305 does not misidentify the simple spaces in the space in front of and behind the truck T as loading spaces. Another example of misidentification is when the truck T is parked significantly beyond the parking area SE, resulting in the cab of the truck T being identified as the end area D1 at the start of travel, causing the simple space in front of the cab to be misidentified as a loading space. Even in such a case, the position determination unit 305 only identifies the position of the two-dimensional LiDAR sensor 22 (origin X0) as the edge of the object adjacent to the loading space on the X-axis coordinate when the area D2 with no degree of resolution includes the position of the two-dimensional LiDAR sensor 22 (origin X0) and when there are intervals S1 and S2 with a degree of resolution or higher on both sides of the area D2. The position determination unit 305 identifies these intervals S1 and S2 as the positions of the edges of the object adjacent to the loading space on the X-axis coordinate. In other words, the position determination unit 305 determines the area D2 without a reading as a loading space only when the position of the two-dimensional LiDAR sensor 22 (origin X0) is included in the area D2 without a reading, and when there are two adjacent sections S1 and S2 with a reading of at least a predetermined value. This prevents the position determination unit 305 from mistakenly identifying a simple space as a loading space.

[0126] Furthermore, refer to Figure 6 A and Figure 6B, the effect of the position determination method based on the edge of the position determination unit 305 is described. Figure 6 A represents the data of the point group PG when the point group PG is acquired at the rear position of the truck T. Figure 6 B represents the data of the point group PG when the position of the two-dimensional LiDAR sensor 22 is on one side of the cab of the truck T. Figure 6 A and Figure 6 As shown in FIG. 1B , a gap in the point group PG occurs in the region from the position of the two-dimensional LiDAR sensor 22 to the point group PG associated with the object that becomes a blind spot. Figure 5 As shown in D, the position determination unit 305 determines the area D2 without degree as the loading space only when the origin X0 is included in the area D2 without degree and there are intervals S1 and interval S2 with degrees above the specified value on both sides of the area D2. Therefore, the gaps in the apparent point group PG involved in the blind spot will not be mistakenly identified as the loading space.

[0127] In particular, Figure 5 As shown in D, regarding the position determination unit 305, (1) the area D2 without degree adjacent to the center of the loading space of the area D1 at the end of the side where the travel for point group acquisition starts among the multiple areas with degree on the X axis is determined as the loading space, and (2) then, the position of the interval S2 with a degree greater than the prescribed degree in the other area D3 (traveling direction side) adjacent to the loading space on the X axis is determined as the position Ex involved in the loading and unloading position LPx of the transport vehicle 1. In this way, the position determination unit 305 can further prevent Figure 6 A and Figure 6 The gaps in the apparent point group PG in B are mistakenly identified as loading spaces.

[0128] When unloading, the loading / unloading target determination unit 306 determines the object on the side of the two objects adjacent to the loading space facing the travel direction on the X-axis (front side) as the unloading target. Furthermore, in another embodiment, when the unloading is set to proceed sequentially from the front side of the plurality of items L loaded on the container Ta, the loading / unloading target determination unit 306 determines the object on the side opposite to the travel direction on the X-axis (rear side) of the two objects adjacent to the loading space as the unloading target.

[0129] During loading, the loading / unloading position determination unit 307 determines a position spaced from position Ex in the direction opposite to the travel direction by half the width W of the cargo L as the loading / unloading position LPx on the X-axis coordinate. Furthermore, during unloading, the loading / unloading position determination unit 307 determines a position spaced from position Ex in the direction of travel by half the width W as the loading / unloading position LPx on the X-axis coordinate. Furthermore, the loading / unloading position determination unit 307 determines the Y coordinate by referring to the Y coordinate of the parking area SE stored in the storage unit 301, for example. Alternatively, the loading / unloading position determination unit 307 may determine the Y coordinate using other known techniques; the method for determining the Y coordinate of the loading / unloading position is not particularly limited.

[0130] The travel control unit 308 is configured to control the drive unit 12 and, when the loading and unloading position LPx is determined by the loading and unloading position determination unit 307 , travel the transport vehicle 1 to the loading and unloading position LPx while referring to the current position acquired by the laser scanner 13 .

[0131] The lifting control unit 309 is configured to control the lifting unit 17 so that the fork 16 is raised to the height for loading and unloading stored in the storage unit 301 by the lifting unit 17 , thereby causing the transport vehicle 1 to perform loading and unloading operations.

[0132] In this way, the transport vehicle 1 analyzes the point group PG acquired by the two-dimensional LiDAR sensor 22 using the degree distribution to determine the edge position Ex of the object adjacent to the loading space on the X axis. As a result, the transport vehicle 1 can determine the edge position Ex relatively easily and universally, and determine the loading and unloading position LPx. Figure 5 The histogram of D is a diagram for explaining the frequency distribution in this specification, and the control unit 30 does not need to specially create a histogram.

[0133] Figure 7 A~ Figure 7 C and Figure 8 A~ Figure 8 C represents another example of obtaining the edge position Ex through frequency distribution analysis performed by the transport vehicle 1 .

[0134] Figure 7 A is a plan view showing an example in which a pallet P is loaded on the front of the container Ta instead of a spacer and a curing material PM is placed on the rear of the container Ta. Figure 7 As shown in B, the transport vehicle 1 also obtains the point group PG through the two-dimensional LiDAR sensor 22, as shown in FIG. Figure 7As shown in C, by using the degree distribution for analysis, the loading space is appropriately determined. Furthermore, the transport vehicle 1 appropriately determines the edge positions of the pallet P and the curing material PM in front and behind the loading space as the edge positions of objects adjacent to and in front of the loading space. This allows the transport vehicle 1 to appropriately place the cargo L in the loading space even when an irregular obstacle is placed in the cargo box Ta.

[0135] Figure 8 A is a plan view showing an example of placing a cylindrical member RM on the front of the cargo box Ta. In this case, Figure 8 As shown in B, the transport vehicle 1 also obtains the point group PG, such as Figure 8 As shown in C, by using the degree distribution for analysis, the loading space is appropriately determined. Furthermore, the transport vehicle 1 appropriately determines the edge position of the cylindrical member RM in front of the loading space as the edge position of the object in front of the loading space. Thus, the transport vehicle 1 can appropriately place the cargo L in the loading space even if an obstacle with a circular side is placed in the cargo box Ta.

[0136] <Flow of the transport vehicle's movement>

[0137] Next, refer to Figure 9 , the flow of the operation of the transport vehicle 1 according to this embodiment will be described.

[0138] (1) The transport vehicle 1 first moves from the rear to the front of the truck T while acquiring the point group PG of the parking area SE (see Figure 9 S (step) 1).

[0139] (2) Next, the transport vehicle 1 analyzes the acquired point group PG using the degree distribution (see Figure 9 S2).

[0140] (3) Next, when the transport vehicle 1 includes the position of the two-dimensional LiDAR sensor 22 (origin X0) in the area D2 with no degree on the X axis and there are sections S1 and S2 with a degree greater than a predetermined degree on both sides of the area D2 with no degree at this time ( Figure 9 If the answer in S3 is Yes, the area D2 without a degree is determined as the loading space ( Figure 9 S4).

[0141] (4) Next, the transport vehicle 1 determines the position of the section S2 adjacent to the loading space in the traveling direction and having a predetermined angle or more as the position Ex related to the loading and unloading position LPx of the transport vehicle 1 ( Figure 9 S5).

[0142] (5) Next, when the transport vehicle 1 is unloading ( Figure 9If the value of S6 is yes), the position that is half the width W of the stacked cargo L along the travel direction from the position of the section S2 is determined as the loading and unloading position LPx ( Figure 9 S7), when loading ( Figure 9 If the result of S6 is No, the position which is half the width W of the stacked cargo L in the opposite direction of the traveling direction from the position of the section S2 is determined as the loading and unloading position LPx ( Figure 9 S8).

[0143] (6) Next, the transport vehicle 1 moves to the determined loading and unloading position LPx and performs the loading and unloading operation ( Figure 9 S9).

[0144] By operating in this manner, the transport vehicle 1 can relatively easily determine the edge position Ex on the X-axis of an object adjacent to the loading space, simultaneously determine the loading and unloading position LPx, and autonomously perform loading and unloading operations. Furthermore, even if the length of the cargo box Ta varies from truck to truck T, or the front and rear parking positions of the truck T vary from operator to operator, the transport vehicle 1 can stably determine the edge position Ex and thereby determine the loading and unloading position LPx.

[0145] While one embodiment of the positioning system and transport vehicle incorporating the positioning system of the present invention has been described above, the present invention is not limited to the aforementioned embodiment. For example, the positioning system and transport vehicle of the present invention may be implemented according to each of the following variations or any combination thereof.

[0146] Modifications

[0147] (1) When the cargo L is placed from the rear of the cargo box Ta, the position determination unit 305 determines the area D1 on the starting travel side (see FIG. Figure 5 D) of the loading space center side adjacent to the substantially no degree of area D2 (refer to Figure 5 D) is determined as the loading space, and then the interval S1 (refer to Figure 5 The position D) is determined as the position Ex related to the loading and unloading position LPx of the transport vehicle 1. Furthermore, the loading and unloading position determination unit 307 determines, during unloading, a position that is half the width W of the stacked goods L in the direction opposite to the traveling direction from the position Ex as the loading and unloading position LPx, and during loading, a position that is half the width W of the stacked goods L in the traveling direction from the position Ex as the loading and unloading position LPx.

[0148] (2) The transport vehicle 1 may also be configured to acquire the point group PG by traveling in the opposite direction to that of the above embodiment, that is, in front of the truck T. In this case, the position determination unit 305 locates the area D1 (refer to the figure) at the end of the traveling direction among the multiple areas with degrees on the X axis. Figure 5 D) of the loading space center side adjacent to the substantially no degree of area D2 (refer to Figure 5 D) is determined as the loading space, and then the interval S2 (refer to Figure 5 The position D) is determined as the position Ex related to the loading and unloading position LPx of the transport vehicle 1. Furthermore, the loading and unloading position determination unit 307 determines, during unloading, a position that is half the width W of the stacked goods L in the direction opposite to the traveling direction from the position Ex as the loading and unloading position LPx, and during loading, a position that is half the width W of the stacked goods L in the traveling direction from the position Ex as the loading and unloading position LPx.

[0149] (3) The position determination unit 305 may be configured not to determine an area smaller than a predetermined distance in an area without a degree on the X-axis as a loading space. Thus, for example, even if an area without a degree is generated in the gap between the cab and the cargo box Ta, the position determination unit 305 may prevent the area in the gap from being determined as a loading space. Furthermore, in other areas, such as those located in the cargo box Ta, Figure 8 A~ Figure 8 Even when there is a gap between the components as shown in C, the position identification unit 305 can prevent the gap from being identified as the loading space.

[0150] (4) The transport vehicle 1 may include the point cloud acquisition unit 22 only on one side, either the left or right side. In this case, if the transport vehicle 1 includes the point cloud acquisition unit 22 only on the right side, the point cloud PG can be appropriately acquired by traveling from the rear to the front of the truck T on the left side of the truck T and from the front to the rear of the truck T on the right side of the truck T.

Claims

1. A position determination system for a transport vehicle, comprising: a point cloud acquisition unit that horizontally irradiates light into the loading space to acquire a point cloud; an analyzing unit for analyzing the obtained point group using a degree distribution with a distance in the X-axis direction as an axis; as well as The position determination unit determines, based on the analysis result of the point group, an area with substantially no degree as a loading space, and determines an interval with a degree greater than a specified degree adjacent to the loading space as the position of an edge on the X-axis coordinate of an object adjacent to the loading space.

2. The position determination system according to claim 1, wherein: The position determination unit includes the position of the point group acquisition unit only in an area with substantially no degree on the X-axis and when there are intervals with a degree greater than a specified degree on both sides of the area with substantially no degree at this time, the interval is determined as the position of the edge on the X-axis coordinate of the object adjacent to the loading space. 3 . The position determining system according to claim 1 , further comprising a loading and unloading object determining unit configured to determine an object adjacent to the loading space as a loading object.

4. The position determination system according to claim 1, wherein: The position identifying unit does not identify an area smaller than a predetermined distance in an area having substantially no degree on the X-axis as the cargo space.

5. The position determination system according to claim 1, wherein: The point cloud acquisition unit irradiates light horizontally to a surrounding space including the loading space and being wider than the loading space in a horizontal direction.

6. The position determination system according to claim 5, wherein: The position determining unit is An area with substantially no degree of angular momentum adjacent to the center of the loading space at the end of the plurality of areas with angular momentum on the X-axis is determined as the loading space. A position of another section having a predetermined angle or greater, adjacent to the determined loading space on the X-axis, is determined as a position related to the loading and unloading position of the transport vehicle.

7. The position determination system according to claim 5, wherein: The position determining unit is An area with substantially no degree adjacent to the center side of the loading space of the endmost area among multiple areas with degrees on the X-axis is determined as the loading space, and the position of the interval with a degree greater than the specified value in the endmost area is determined as the position related to the loading and unloading position of the transport vehicle.

8. A transport vehicle comprising the position determination system according to any one of claims 1 to 7.

9. A method for determining a position of a transport vehicle, the method comprising: The point cloud acquiring unit horizontally irradiates the loading space with light to acquire a point cloud. Analyzing the obtained point group using a degree distribution with the distance in the X-axis direction as an axis; Based on the analysis results of the point group, determining an area with substantially no degree as a loading space; as well as A section having a predetermined degree or greater and adjacent to the cargo space is determined as a position of an edge of the object adjacent to the cargo space on the X-axis coordinate.

10. The position determination method according to claim 9, wherein: When the position of the point group acquisition unit is included only in an area with substantially no degree on the X-axis and when there are intervals with a degree greater than a specified degree on both sides of the area with substantially no degree at this time, the interval is determined as the position of the edge on the X-axis coordinate of the object adjacent to the loading space.

11. The method for determining a position according to claim 9, wherein: The method further includes determining an object adjacent to the loading space as a discharge target.

12. The position determination method according to claim 9, wherein: In the region with substantially no degree on the X-axis, a region smaller than a predetermined distance is not determined as the cargo space.

13. The position determination method according to claim 9, wherein: acquiring the point group by horizontally irradiating light onto a surrounding space including the loading space and being wider than the loading space in a horizontal direction; An area with substantially no degree of angular momentum adjacent to the center of the loading space at the end of the plurality of areas with angular momentum on the X-axis is determined as the loading space. A position of another section having a predetermined angle or greater, adjacent to the determined loading space on the X-axis, is determined as a position related to the loading and unloading position of the transport vehicle.

14. The position determination method according to claim 9, wherein: acquiring the point group by horizontally irradiating light onto a surrounding space including the loading space and being wider than the loading space in a horizontal direction; An area with substantially no degree adjacent to the center side of the loading space of the endmost area among multiple areas with degrees on the X-axis is determined as the loading space, and the position of the interval with a degree greater than the specified value in the endmost area is determined as the position related to the loading and unloading position of the transport vehicle.

15. A computer-readable storage medium having a position determination program stored thereon, the computer-readable storage medium being a program for a transport vehicle, the transport vehicle comprising a point cloud acquisition unit for horizontally irradiating light onto a loading space to acquire a point cloud, and computer, The position determination program causes the computer to execute Analyzing the obtained point group using a degree distribution with the distance in the X-axis direction as an axis; Based on the analysis results of the point group, determining an area with substantially no degree as a loading space; as well as A section having a predetermined degree or greater and adjacent to the cargo space is determined as a position of an edge of the object adjacent to the cargo space on the X-axis coordinate.

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