Position specifying system

Abstract

To specify an edge position in an X-axis coordinate of an object adjacent to a cargo storage space in a relatively simple and versatile manner to determine a cargo handling position in the X-axis coordinate.SOLUTION: A position specifying system includes a point cloud acquisition unit 22 that horizontally emits light onto a space above a loading platform Ta to acquire a point cloud PG, an analysis unit, and a position specifying unit. The analysis unit analyzes the acquired point cloud PG by using a frequency distribution with a distance in an X-axis direction as an axis. Based on analysis results of the point cloud PG, the position specifying unit specifies an area D2 with virtually no frequency as a loading space, and specifies sections S1 and S2 adjacent to the loading space with a frequency equal to or greater than a predetermined value as an edge position in an X-axis coordinate of an object adjacent to the loading space.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a position specifying system for specifying the position of an edge of an object related to a loading position of a transport vehicle. [Background technology]

[0002] As disclosed in Patent Document 1, an automated guided vehicle that travels autonomously and performs loading and unloading work is known. This type of automated guided vehicle is equipped with forks, a lifting device that raises and lowers the forks, and a laser scanner that detects its own position. The automated guided vehicle is configured to move to a predetermined loading and unloading position while detecting its own position, and then raise and lower the forks to perform loading and unloading work.

[0003] As shown in FIG. 10, this type of automated guided vehicle 100 may perform loading and unloading operations on the loading platform Ta of a truck T. However, unlike a fixed shelf, the truck T may not stop at a fixed position. For this reason, the loading position of the automated guided vehicle 100 cannot be determined in advance. Also, since the length of the loading platform Ta of the truck T differs depending on the vehicle model, the loading position will differ for each truck T even if the truck stops at a fixed position. Furthermore, to make effective use of the loading platform Ta of the truck T, it is necessary to pack and store the loads L. However, in order to do this, the position of the load L loaded on the loading platform Ta must first be identified before the position of the load L to be placed next can be determined.

[0004] For example, there is an automated guided vehicle (forklift) as disclosed in Literature 2. This automated guided vehicle is equipped with an external sensor that detects the position of an object using coordinates in a three-dimensional coordinate system, and (1) extracts points representing a horizontal plane from point cloud data, which is a collection of points representing the position of the object, (2) extracts points within a predetermined range in the vertical direction from the horizontal plane as points representing the loading platform, and (3) extracts points representing the edge of the loading platform from the points representing the loading platform. Furthermore, this automated guided vehicle is configured to (4) detect a straight line representing the edge from the points representing the edge, (5) extract points that are a predetermined distance or more above the horizontal plane as points representing loads placed on the loading platform, and (6) detect a position that is a specified distance away from the load in the direction of the straight line as a loading position for loading the load onto the loading platform.

[0005] However, this type of object detection (extraction) method using point cloud data involves processes such as clustering (classifying multiple point clouds into certain sets) and pattern matching (e.g., extracting straight lines). This method requires high accuracy (high resolution of point cloud data), and as a result, it requires the use of a computer with high data processing capabilities. In addition, this method requires that the judgment algorithm and pattern be adjusted for each object, making it difficult to make it versatile. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-030642 [Patent Document 2] Japanese Patent Publication No. 2023-030983 Summary of the Invention [Problem to be solved by the invention]

[0007] As shown in FIG. 10A, a truck T to be loaded usually stops in a parking area SE in a predetermined orientation. The width W of the load L can also be the width of a specified pallet on which the load is placed. Therefore, if the edge position Ex on the X-axis of an object (e.g., load L) adjacent to the loading space can be identified, a position located half the width W from the edge position Ex in the opposite direction of the object can be determined as the loading position LPx in the X-axis coordinate when the load is placed. Also, as shown in FIG. 10B, if the edge position Ex on the X-axis of the load L placed on the loading platform Ta can be identified, a position located half the width W from the edge position Ex toward the center of the load L can be determined as the loading position LPx in the X-axis coordinate when the load is removed. Note that, for simplicity of explanation in FIG. 10, the width W of the load L is set to the width of the pallet, but the width W of the load L does not have to be the same as the pallet. For example, even if the width W of the load L is longer or shorter than the width of the pallet, the load handling position LPx can be determined as long as the width W of the load L is known or within a predetermined range.

[0008] Therefore, the problem that the present invention aims to solve is to provide a position identification system that can relatively easily and versatility identify the edge position in the X-axis coordinate of an object adjacent to a loading space in order to determine the loading position in the X-axis coordinate. [Means for solving the problem]

[0009] In order to solve the above problem, the positioning system according to the present invention comprises: The position identification system for use in a transport vehicle includes a point cloud acquisition unit that horizontally irradiates a load space with light to acquire a point cloud, an analysis unit that analyzes the acquired point cloud using a frequency distribution with the distance in the X-axis direction as an axis, and a position identification unit that, based on the analysis results of the point cloud, identifies an area with virtually no frequency as a load space and identifies a section adjacent to the load space with a frequency equal to or greater than a predetermined value as the edge position in the X-axis coordinate of an object adjacent to the load space. Note that "horizontal" in this invention also includes angles that are not perpendicular to the direction of gravity when, for example, the ground is sloped.

[0010] The location system preferably comprises: The position identification unit identifies the section as the edge position in the X-axis coordinate of an object adjacent to the loading space only when the position of the point cloud acquisition unit is included in an area on the X-axis with substantially no power and there are sections with a power of a predetermined value or more on both sides of the area with substantially no power.

[0011] The location system preferably comprises: The system further includes a loading target determination unit that determines an object adjacent to the loading space as a loading target.

[0012] The location system preferably comprises: The position specifying unit does not specify, as a luggage space, an area on the X axis that is substantially free of power and that is less than a predetermined distance away.

[0013] The location system preferably comprises: The point cloud acquisition unit horizontally irradiates light onto a surrounding space that includes the loading space and is wider in the horizontal direction than the loading space.

[0014] The location system preferably comprises: The position identification unit identifies, on the X axis, an area with substantially no power adjacent to the center of the loading space of the endmost area among the areas with multiple powers, as a loading space, and identifies, on the X axis, the position of another section with a power equal to or greater than a predetermined value adjacent to the identified loading space, as a position related to the loading position of the transport vehicle.

[0015] The location system preferably comprises: The position identification unit identifies, on the X-axis, an area with virtually no power adjacent to the center of the loading space of the most extreme area among the areas with multiple powers, as a loading space, and identifies the position of a section of the most extreme area with a power equal to or greater than a predetermined value as a position related to the loading position of the transport vehicle.

[0016] In order to solve the above problem, a transport vehicle according to the present invention includes any one of the above-described position specifying systems.

[0017] In order to solve the above problem, a location identification method according to the present invention includes: A position identification method used in a transport vehicle, comprising: acquiring a point cloud by irradiating light horizontally onto a loading space using a point cloud acquisition unit; analyzing the acquired point cloud using a frequency distribution with distance in the X-axis direction as an axis; identifying an area with substantially no frequency as a loading space based on the analysis results of the point cloud; and identifying a section adjacent to the loading space with a frequency equal to or greater than a predetermined value as the edge position in the X-axis coordinate of an object adjacent to the loading space.

[0018] The location determination method preferably comprises: Only when the position of the point cloud acquisition unit is included in an area on the X axis where there is essentially no power, and there are sections on both sides of this area where there is essentially no power that have a power equal to or greater than a predetermined value, is that section identified as the position of the edge on the X axis of an object adjacent to the loading space.

[0019] The location determination method preferably comprises: The method further includes determining an object adjacent to the loading space as a loading target.

[0020] The location determination method preferably comprises: Among the areas on the X axis where there is substantially no power, areas that are less than a predetermined distance away are not identified as luggage storage spaces.

[0021] The location determination method preferably comprises: A point cloud is acquired by irradiating light horizontally onto the surrounding space, which includes the loading space and is wider in the horizontal direction than the loading space, On the X axis, an area with substantially no power adjacent to the center of the loading space of the end area among the areas with multiple powers is identified as the cargo storage space; On the X-axis, the position of another section adjacent to the identified loading space and having a frequency equal to or greater than a predetermined frequency is identified as the position related to the loading position of the transporting vehicle.

[0022] The location determination method preferably comprises: A point cloud is acquired by irradiating light horizontally onto the surrounding space, which includes the loading space and is wider in the horizontal direction than the loading space, On the X axis, an area with substantially no power adjacent to the center of the loading space of the end area among the areas with multiple powers is identified as the cargo storage space; The position of the section in the endmost region where the frequency is equal to or greater than a predetermined value is identified as the position related to the loading position of the transport vehicle.

[0023] In order to solve the above problem, a location identification program according to the present invention includes: A program used in a transport vehicle including a point cloud acquisition unit that horizontally irradiates a loading space with light to acquire a point cloud, and a computer, On the computer, Analyzing the acquired point cloud using a frequency distribution with the distance in the X-axis direction as an axis; Identifying a substantially non-frequency region as a loading space based on the analysis result of the point cloud; and identifying a section adjacent to the loading space having a frequency equal to or greater than a predetermined frequency as the position of an edge in the X-axis coordinate of an object adjacent to the loading space. [Effects of the Invention]

[0024] The position specifying system according to the present invention can specify the edge position in the X-axis coordinate of an object adjacent to a loading space relatively easily and with versatility. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a plan view showing a truck and an automated guided vehicle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a side view showing the automated guided vehicle shown in FIG. [Figure 3] FIG. 2 is a block diagram of an automated guided vehicle. [Figure 4] 3A and 3B show the connecting portion shown in FIG. 2, in which A is a perspective view from above the rear, B is a plan view, and C is a rear view. [Figure 5]A is a plan view showing the laser irradiation of the 2D LiDAR sensor on the right, B is a diagram showing the point cloud acquired by the 2D LiDAR sensor on the right, C is a diagram showing mask processing of the point cloud in B within a specified range, and D is a diagram showing the point cloud in C displayed as a histogram in the X-axis direction. [Figure 6] A shows the point cloud data when the point cloud was acquired at a position behind the truck, and B shows the point cloud data when the point cloud was acquired at the side of the truck cab. [Figure 7] A is a plan view showing the loading platform on which protective materials and pallets are placed, B is a diagram showing the point cloud acquired by the 2D LiDAR sensor on the right side of the loading platform in A, and C is a diagram showing the point cloud in B displayed as a histogram in the X-axis direction. [Figure 8] A is a plan view showing the loading platform on which the cylindrical members are placed, B is a diagram showing the point cloud acquired by the 2D LiDAR sensor on the right side of the loading platform in A, and C is a diagram showing the point cloud in B displayed as a histogram in the X-axis direction. [Figure 9] FIG. 10 is a flow diagram showing the flow of operation of the automated guided vehicle. [Figure 10] FIG. 1 is a plan view showing a conventional automated guided vehicle and a truck bed. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, an embodiment of a positioning system and a transport vehicle equipped with the positioning system of the present invention will be described with reference to the accompanying drawings. In the drawings, a double-headed arrow X indicates the front-rear direction (X axis), a double-headed arrow Y indicates the left-right direction, and a double-headed arrow Z indicates the up-down direction.

[0027] FIG. 1 is a plan view showing a truck T and a transport vehicle 1 according to this embodiment. As shown in FIG. 1, the truck T has a loading platform Ta at the rear and stops in a stopping area SE surrounded by a white line WL. The space above the loading platform Ta corresponds to the "loading space" of the present invention, and the space above the stopping area SE corresponds to the "surrounding space" of the present invention. However, these are merely examples, and the place where loading and unloading is performed in the present invention is not limited to the loading platform Ta of the truck T. For example, if loading and unloading is performed on a shelf or a container, the space above the shelf or container corresponds to the "loading space" of the present invention, and the surrounding space including this shelf or container corresponds to the "surrounding space" of the present invention.

[0028] In this embodiment, the transport vehicle 1 is configured to acquire a point cloud PG while traveling from the rear to the front of the truck T on the left and right sides of the truck T, and to perform cargo handling operations at a cargo handling position LPx determined based on the acquired point cloud PG. In this embodiment, the transport vehicle 1 is configured to deposit cargo from the space in front of the loading platform Ta, and to retrieve cargo from the rearmost load L among multiple loads L loaded on the loading platform Ta. The transport vehicle 1 according to this embodiment is an unmanned transport vehicle that autonomously travels and handles cargo, but this is merely an example, and the transport vehicle according to the present invention is not limited to this. For example, the transport vehicle according to the present invention may be a transport vehicle that can be used both as a manned and an unmanned transport vehicle.

[0029] <Configuration of the transport vehicle> Fig. 2 is a side view of the transport vehicle 1, and Fig. 3 is a block diagram of the transport vehicle 1. As shown in Figs. 2 and 3, 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 lift unit 17, a backrest 18, left and right 2D LiDAR sensors 22, left and right connecting units 23, and a control unit 30. The transport vehicle 1 is a reach forklift, but this is also just one example, and the transport vehicle 1 according to the present invention may also be a counter-load forklift.

[0030] 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 and stop the wheels 10.

[0031] The laser scanner 13 is disposed above the vehicle body 11 and rotates horizontally to irradiate a laser beam and scan the reflected laser light.

[0032] The left and right masts 14 extend vertically and are disposed at the rear of the vehicle body 11. The lift bracket 15 has finger bars for fixing the left and right forks 16, and is configured to be raised and lowered along the left and right masts 14 by the lifting unit 17. In this embodiment, the number of forks 16 is four, but it may be two or six, and is not particularly limited.

[0033] The backrest 18 is formed in a frame shape, extends vertically and horizontally, and is configured to receive a load L. In FIG. 4, only the outer frame of the backrest 18 is shown, and this outer frame is disposed outward in the left-right direction from the vehicle body 11.

[0034] The left and right 2D LiDAR sensors 22 are configured as laser scanners that rotate horizontally while emitting a laser and scanning the reflected light of the laser to acquire the distance to the object irradiated with the laser as a point cloud PG. The 2D LiDAR sensors 22 correspond to the "point cloud acquisition unit" of the present invention. The point cloud acquisition unit of the present invention may be, for example, a 3D LiDAR sensor or a 3D ToF (Time of Flight) camera instead of the 2D LiDAR sensor 22, and is not limited to a 2D LiDAR sensor. As such, "light" in the present invention includes not only visible light but also invisible light.

[0035] FIG. 4 shows the connecting portion 23, with A being a perspective view from above of the rear surface (the fork 16 side), B being a plan view, and C being a rear view. The connecting portion 23 has a first end portion 23a, an intermediate 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 intermediate portion 23b extends from the first end portion 23a diagonally forward of the backrest 18 in a plan view. The second end portion 23c has a horizontal surface continuing from the intermediate portion 23b, and this horizontal surface supports the 2D LiDAR sensor 22. The second end portion 23c is configured to be positioned outward in the left-right direction from the load L loaded on the fork 16 and the side surface of the vehicle body 11. This allows the laser of the 2D LiDAR sensor 22 to be irradiated toward the parking area SE, including the loading platform Ta, without being blocked by the loaded load L or the vehicle body 11.

[0036] FIG. 5A shows an example of the laser irradiation range LE of the 2D LiDAR sensor 22 and indicates the traveling direction of the guided vehicle 1. Note that the laser irradiation range LE is not limited to this range, and the laser may be irradiated to reach the entire stopping area SE. As shown in FIG. 5A, the guided vehicle 1 travels beside the truck T from rear to front, and the 2D LiDAR sensor 22 rotates horizontally while emitting a laser and receiving reflected light, thereby acquiring the distance to the object for each irradiation angle. This distance data is acquired as a point cloud PG as shown in FIG. 5B. The intersection of the X-axis and Y-axis in FIG. 5B indicates the position of the 2D LiDAR, which is the origin X0. Note that the point cloud PG in the attached figure is an image diagram showing an example of the acquired point cloud PG and is not the actually acquired point cloud PG.

[0037] In the present invention, the acquisition of the point cloud PG by the two-dimensional LiDAR sensor 22 may be performed while the guided vehicle 1 is stopped, and the guided vehicle 1 does not necessarily need to run parallel to the truck T to acquire the point cloud PG.

[0038] Naturally, if the absolute position coordinates of the transport vehicle 1 can be recognized by known technology, the absolute position coordinates of the 2D LiDAR sensor 22 can also be identified, and the position of the acquired point cloud PG can also be identified on the absolute coordinate axes. In other words, Fig. 5B is also a diagram showing the point cloud PG shown on the absolute coordinate axes and the current positional relationship of the transport vehicle 1 with respect to the point cloud PG.

[0039] 2, the control unit 30 is disposed inside the vehicle body 11. The control unit 30 is configured by a computer having a storage device, a calculation unit, and a memory. The storage device stores a position identification program that causes the computer to execute the edge position identification method.

[0040] <Functional configuration of the control unit> Next, the functional configuration of the control unit 30 will be described. As shown in Fig. 3, the control unit 30 has a memory unit 301, an own aircraft position recognition unit 302, an analysis unit 303, a position identification unit 305, a loading object determination unit 306, a loading position determination unit 307, a travel control unit 308, and an elevation control unit 309. A system including the two-dimensional LiDAR sensor 22 (point cloud acquisition unit), the analysis unit 303, the position identification unit 305, and the loading object determination unit 306 corresponds to the "position identification system" of the present invention.

[0041] The memory unit 301 stores the position (X coordinate, Y coordinate) of the stopping area SE, the front or rear orientation of the stopped truck T, the width W of the load L, and the height to which the forks 16 are raised during loading.

[0042] The vehicle position recognition unit 302 detects the position of a reflector placed within the facility from the reflected light scanned by the laser scanner 13, thereby recognizing the current position of the transportation vehicle 1.

[0043] The analysis unit 303 analyzes the acquired point cloud PG using a frequency distribution with the distance in the X-axis direction as an axis. Specifically, the analysis unit 303 first limits the acquired point cloud PG to a point cloud PG within a region of interest (ROI), which is the range indicated by the dashed line in FIG. 5, as shown in FIG. 5C. In this way, the analysis unit 303 eliminates unnecessary point clouds PG. Next, the analysis unit 303 analyzes the point cloud PG within the ROI using a frequency distribution at a distance in the X-axis direction from an origin X0 on the X-axis (front-back direction), as shown in FIG. 5D.

[0044] The area D2 with no power in FIG. 5D indicates an area where the reflection of the laser by the 2D LiDAR sensor 22 is extremely lower than other areas or is nonexistent. In the present invention, "substantially no power" means excluding cases where there is power in an area where there is nothing due to noise or the like. The analysis unit 303 may use known technology to remove power due to noise or the like, or may ignore low power during analysis. Hereinafter, the term "substantially no power" will be abbreviated to "no power."

[0045] Since each interval has its own range of values, the average value of the values ​​in each interval may be used as the position (X coordinate) of that interval, or the minimum or maximum value in each interval may be used as the position (X coordinate) of that interval.

[0046] Based on the analysis results of the point cloud PG, the position identification unit 305 identifies the area D2 with no frequency as a storage space, and identifies sections S1 and S2 adjacent to the storage space with a frequency equal to or greater than a predetermined value as the position of an edge on the X-axis coordinate of an object adjacent to the storage space, as shown in FIG. 5D. By using "a frequency equal to or greater than a predetermined value," the position identification unit 305 can appropriately identify the section of the area D1 or D2 with frequency that corresponds to the edge of the object on the X-axis. The minimum frequency for identifying the edge position is appropriately set in advance so as to identify the section of the edge of the object while avoiding erroneously recognizing other sections as edge sections.

[0047] The position identification unit 305 preferably identifies the sections S1 and S2 as the edge positions in the X-axis coordinate of an object adjacent to the loading space only when the position of the two-dimensional LiDAR sensor 22 (origin X0) is included in the area D2 with no degree on the X-axis and when there are sections S1 and S2 with a degree of a predetermined value or more on both sides of the area D2 with no degree at that time.

[0048] This prevents the position identification unit 305 from erroneously recognizing a simple space as a cargo space. For example, since the stopping area SE has a length that is sufficiently longer than the overall length of the truck T, it is assumed that there is space in front of and behind the stopped truck T. The 2D LiDAR sensor 22 does not acquire a point cloud PG from the space in this space. Therefore, the position identification unit 305 does not erroneously recognize a simple space in front of and behind the truck T as a cargo space. An example of erroneous recognition is when the stopping position of the truck T extends significantly rearward from the stopping area SE, resulting in the cab of the truck T being recognized as the extreme area D1 on the side where the truck T starts traveling, and therefore the simple space in front of the cab being erroneously recognized as a cargo space. Even in such a case, the position identifying unit 305 identifies the sections S1 and S2 as the edge position in the X-axis coordinate of the object adjacent to the storage space only when the position (origin X0) of the 2D LiDAR sensor 22 is included in the region D2 with no power and there are sections S1 and S2 with a power of a predetermined level or more on both sides of the region D2. In other words, the position identifying unit 305 identifies the region D2 with no power as a storage space only when the position (origin X0) of the 2D LiDAR sensor 22 is included in the region D2 with no power and there are sections S1 and S2 with a power of a predetermined level or more on both sides of the region D2. In this way, the position identifying unit 305 prevents a simple space from being mistakenly recognized as a storage space.

[0049] Furthermore, the effect of the edge position identification method by the position identification unit 305 will be described with reference to FIG. 6. FIG. 6A shows data of the point cloud PG when the point cloud PG is acquired at a position behind the truck T, and FIG. 6B shows data of the point cloud PG when the 2D LiDAR sensor 22 is positioned to the side of the cab of the truck T. As shown in FIGS. 6A and 6B, gaps in the point cloud PG occur in regions of the point cloud PG associated with objects in a blind spot from the position of the 2D LiDAR sensor 22. However, as shown in FIG. 5D, the position identification unit 305 identifies the region D2 with no power as a load space only when the origin X0 is included in the region D2 with no power and when sections S1 and S2 with a power equal to or greater than a predetermined value are located on both sides of the region D2. Therefore, the apparent gaps in the point cloud PG associated with the blind spot are not erroneously recognized as a load space.

[0050] In particular, as shown in Fig. 5D, the position specifying unit 305 (1) specifies, on the X axis, among the regions with multiple frequencies, a region D2 with no frequency adjacent to the center of the loading space of the region D1 at the extreme end on the side where travel for point cloud acquisition starts, as the loading space, and (2) then specifies, on the X axis, the position of a section S2 with a frequency equal to or greater than a predetermined value in the other region D3 (on the traveling direction side) adjacent to the loading space, as the position Ex related to the loading position LPx of the transporting vehicle 1. This makes it possible for the position specifying unit 305 to further prevent erroneous recognition of gaps in the apparent point cloud PG in Figs. 6A and 6B as loading spaces.

[0051] When picking up an object, the handling object determination unit 306 determines, of two objects adjacent to the loading space, the object on the traveling direction side (front side) on the X axis as the object to be picked up. In another embodiment, when the loading system is set to pick up multiple objects L loaded on the loading platform Ta in order from the front, the handling object determination unit 306 determines, of the two objects adjacent to the loading space, the object on the opposite side of the traveling direction on the X axis (rear side) as the object to be picked up.

[0052] When placing a load, the loading position determination unit 307 determines a position on the X-axis coordinate that is half the width W of the load L from the position Ex in the direction opposite to the traveling direction as the loading position LPx. When picking up a load, the loading position determination unit 307 determines a position on the X-axis coordinate that is half the width W from the position Ex in the traveling direction as the loading position LPx. Note that the loading position determination unit 307 determines the Y coordinate by referring to the Y coordinate of the stopping area SE stored in the memory unit 301. Alternatively, the loading position determination unit 307 may determine the Y coordinate by other known techniques, and there is no particular limitation on the method for determining the Y coordinate of the loading position.

[0053] The travel control unit 308 is configured to control the drive unit 12, and when the loading position LPx is determined by the loading position determination unit 307, the travel control unit 308 causes the transport vehicle 1 to travel to the loading position LPx while referring to the current position acquired by the laser scanner 13.

[0054] The lifting control unit 309 is configured to control the lifting unit 17, and causes the lifting unit 17 to raise the fork 16 to the height at the time of loading and unloading stored in the memory unit 301, thereby causing the transport vehicle 1 to perform loading and unloading work.

[0055] In this way, the transport vehicle 1 can identify the edge position Ex on the X-axis of an object adjacent to the loading space by analyzing the point cloud PG acquired by the 2D LiDAR sensor 22 using the frequency distribution. This allows the transport vehicle 1 to identify the edge position Ex relatively easily and versatility, and determine the loading position LPx. Note that the histogram in Figure 5D is for explaining the frequency distribution in this specification, and there is no particular need for the control unit 30 to create a histogram.

[0056] 7 and 8 show another example in which the edge position Ex can be obtained by frequency distribution analysis using the carrier 1. FIG.

[0057] FIG. 7A is a plan view showing an example in which a pallet P is loaded in place of a spacer at the front of the loading platform Ta, and protective material PM is placed at the rear of the loading platform Ta. In this case, too, the transport vehicle 1 acquires a point cloud PG using the 2D LiDAR sensor 22 as shown in FIG. 7B, and analyzes it using a frequency distribution as shown in FIG. 7C, thereby appropriately identifying the loading space. Furthermore, the transport vehicle 1 appropriately identifies the edge positions of the pallet P and the protective material PM at the front and rear of the loading space as the edge positions of the objects at the front and rear of the loading space. This allows the transport vehicle 1 to appropriately place the load L in the loading space even when an irregular obstacle is placed on the loading platform Ta.

[0058] FIG. 8A is a plan view showing an example in which a cylindrical member RM is placed at the front of the loading platform Ta. In this case, too, the transport vehicle 1 acquires a point cloud PG as shown in FIG. 8B and analyzes it using a frequency distribution as shown in FIG. 8C, thereby appropriately identifying the loading space. Furthermore, the transport vehicle 1 appropriately identifies the edge position of the cylindrical member RM in front of the loading space as the edge position of the front object adjacent to the loading space. This allows the transport vehicle 1 to appropriately place the load L in the loading space even when an obstacle with a rounded side is placed on the loading platform Ta.

[0059] <Transport vehicle operation flow> Next, the flow of operations of the transport vehicle 1 according to this embodiment will be described with reference to FIG.

[0060] (1) First, the guided vehicle 1 travels from the rear to the front of the truck T, and acquires a point cloud PG of the stopping area SE (see S (step) 1 in FIG. 9).

[0061] (2) Next, the transfer vehicle 1 analyzes the acquired point cloud PG using frequency distribution (see S2 in FIG. 9).

[0062] (3) Next, if the position of the 2D LiDAR sensor 22 (origin X0) is included in the area D2 with no degree on the X-axis, and there are sections S1 and S2 with a degree of a predetermined value or more on either side of the area D2 with no degree at this time (Yes in S3 of Figure 9), the transport vehicle 1 identifies the area D2 with no degree as a loading space (S4 of Figure 9).

[0063] (4) Next, the transporting vehicle 1 identifies the position of the section S2 adjacent to the loading space in the traveling direction and having a frequency equal to or greater than a predetermined frequency as the position Ex related to the loading position LPx of the transporting vehicle 1 (S5 in FIG. 9).

[0064] (5) Next, when picking up cargo (Yes in S6 of Figure 9), the transport vehicle 1 determines the position that is half the width W of the cargo L in the direction of travel from the position of section S2 as the loading position LPx (S7 of Figure 9), and when putting down cargo (No in S6 of Figure 9), it determines the position that is half the width W of the cargo L in the opposite direction of travel from the position of section S2 as the loading position LPx (S8 of Figure 9).

[0065] (6) Next, the transport vehicle 1 moves to the determined loading position LPx and performs loading work (S9 in FIG. 9).

[0066] By operating in this manner, the transport vehicle 1 can determine the loading position LPx and autonomously perform loading and unloading work while relatively easily identifying the edge position Ex on the X-axis of the object adjacent to the loading space. Furthermore, even if the length of the loading platform Ta differs for each truck T or the positions of the front and rear stopping positions of the truck T differ for each driver, the transport vehicle 1 can stably identify the edge position Ex and determine the loading and unloading position LPx.

[0067] Although one embodiment of the positioning system and the transport vehicle equipped with the positioning system of the present invention has been described above, the present invention is not limited to the above embodiment. For example, the positioning system and the transport vehicle according to the present invention may be implemented by each of the following modifications or by combining the following modifications as appropriate.

[0068] <Modification>

[0069] (1) In the case where the load L is set to be placed from the rear of the loading platform Ta, the position identification unit 305 identifies, among the regions with multiple intensities on the X axis, an area D2 (see FIG. 5D) with substantially no intensities adjacent to the center of the loading space of the area D1 (see FIG. 5D) on the side where travel starts, as the load placement space, and then identifies the position of a section S1 (see FIG. 5D) in area D2 with an intensities equal to or greater than a predetermined value as the position Ex related to the loading position LPx of the transporting vehicle 1. Then, the loading position determination unit 307 determines, when picking up the load, a position at a distance half the width W of the load L from the position Ex in the direction opposite to the traveling direction as the loading position LPx, and when placing the load, determines, when picking up the load, a position at a distance half the width W of the load L from the position Ex in the traveling direction as the loading position LPx.

[0070] (2) The transport vehicle 1 may be configured to travel in the opposite direction to the above embodiment, i.e., from the front of the truck T, and acquire the point cloud PG. In this case, the position identification unit 305 identifies, on the X-axis, among areas with multiple intensities, an area D2 (see FIG. 5D) with substantially no intensities adjacent to the center of the loading space of an area D1 (see FIG. 5D) at the extreme end in the traveling direction, as the loading space. Next, the position identification unit 305 identifies the position of a section S2 (see FIG. 5D) on the other side adjacent to the identified loading space, which has an intensities equal to or greater than a predetermined value, as the position Ex related to the loading position LPx of the transport vehicle 1. Then, the loading position determination unit 307 determines, when picking up a load, a position at a distance half the width W of the load L from the position Ex in the opposite direction to the traveling direction as the loading position LPx. When putting a load down, the position at a distance half the width W of the load L from the position Ex in the traveling direction as the loading position LPx.

[0071] (3) The position identifying unit 305 may be configured not to identify, as a cargo space, an area of ​​no power on the X-axis that is less than a predetermined distance. This allows the position identifying unit 305 to prevent the area of ​​this gap from being identified as a cargo space, even when, for example, an area of ​​no power is generated in the gap between the cab and the loading platform Ta. Furthermore, even when there is a gap between components disposed on the loading platform Ta, such as that shown in FIG. 8, the position identifying unit 305 can prevent the area from being identified as a cargo space.

[0072] (4) The transport vehicle 1 may be provided with the point cloud acquisition unit 22 on only one side, either the left or right. In this case, if the transport vehicle 1 has the point cloud acquisition unit 22 only on the right side, the transport vehicle 1 can appropriately acquire the point cloud PG by traveling from the rear to the front of the truck T on the left side of the truck T and traveling from the front to the rear of the truck T on the right side of the truck T. [Explanation of symbols]

[0073] L load LE laser irradiation range LPx Loading position P Palette PG point cloud PM curing material ROI Region of Internet RM cylindrical member SE Stop Area T-track Ta Cargo bed WL white line W Load width 1 transport vehicle 10 wheels 11 Body 12 Drive unit 13 Laser scanner 14 Mast 15 Lift bracket 16 forks 17 Lifting section 18 Backrest 22 2D LiDAR sensor (point cloud acquisition unit) 23 Connecting part 23a First end 23b Middle part 23c 2nd end 30 Control Unit 301 Storage section 302 Own aircraft position recognition unit 303 Analysis Department 305 Location identification part 306 Cargo Handling Determination Department 307 Loading position determination unit 308 Driving control unit 309 Lift control section

Claims

1. A position identification system for use in a transport vehicle, comprising: a point cloud acquisition unit that horizontally irradiates light onto the loading space to acquire a point cloud; an analysis unit that analyzes the acquired point cloud using a frequency distribution with the distance in the X-axis direction as an axis; and a position identification unit that, based on the analysis results of the point cloud, identifies an area with substantially no frequency as a loading space, and identifies a section adjacent to the loading space with a frequency equal to or greater than a predetermined value as the edge position in the X-axis coordinate of an object adjacent to the loading space.

2. 2. The position identification system according to claim 1, wherein the position identification unit identifies an area on the X-axis with substantially no power as the position of an edge in the X-axis coordinate of an object adjacent to the loading space only when the position of the point cloud acquisition unit is included in an area on the X-axis with substantially no power and when there are areas with a power of a predetermined value or more on both sides of the area with substantially no power.

3. The position specifying system according to claim 1 , further comprising a loading target determining unit that determines an object adjacent to the loading space as a loading target.

4. The position specifying system according to claim 1 , wherein the position specifying unit does not specify, as the loading space, an area on the X axis that is substantially free of power and that is less than a predetermined distance away.

5. The position specifying system according to claim 1 , wherein the point cloud acquisition unit horizontally irradiates light onto a surrounding space that includes the loading space and is wider in the horizontal direction than the loading space.

6. The position identification unit On the X axis, an area with substantially no power that is adjacent to the center of the loading space of the end area among the areas with multiple powers is identified as the loading space, 6. The position specifying system according to claim 5, wherein the position of another section on the X axis adjacent to the specified loading space and having a frequency equal to or greater than a predetermined frequency is specified as the position related to the loading position of the transport vehicle.

7. The position identification unit 6. The position identification system according to claim 5, wherein an area on the X-axis with substantially no power adjacent to the center of the loading space of the most extreme area among areas with multiple powers is identified as the loading space, and the position of a section of the most extreme area with a power equal to or greater than a predetermined value is identified as a position related to the loading position of the transport vehicle.

8. A transport vehicle equipped with the position specifying system according to any one of claims 1 to 7.

9. A location identification method for use in a transport vehicle, comprising: A point cloud is acquired by irradiating light horizontally onto the loading space using a point cloud acquisition unit; Analyzing the acquired point cloud using a frequency distribution with the distance in the X-axis direction as an axis; Identifying a region with substantially no frequency as a storage space based on the analysis result of the point cloud; and identifying a section adjacent to the loading space having a frequency equal to or greater than a predetermined frequency as the position of an edge in the X-axis coordinate of an object adjacent to the loading space.

10. 10. The position identification method according to claim 9, wherein only when the position of the point cloud acquisition unit is included in an area on the X-axis with substantially no power, and when there are sections with a power of a predetermined value or more on both sides of the area with substantially no power, the section is identified as the edge position in the X-axis coordinate of an object adjacent to the loading space.

11. The method of claim 9 further comprising determining an object adjacent to the loading space as a loading target.

12. The position specifying method according to claim 9, wherein an area on the X axis with substantially no power that is less than a predetermined distance away is not specified as the loading space.

13. acquiring the point cloud by irradiating light horizontally onto a surrounding space that includes the loading space and is wider in the horizontal direction than the loading space; On the X axis, an area with substantially no power that is adjacent to the center of the loading space of the end area among the areas with multiple powers is identified as the loading space, The position specifying method according to claim 9, wherein the position of another section on the X axis adjacent to the specified loading space and having a frequency equal to or greater than a predetermined frequency is specified as the position related to the loading position of the transporting vehicle.

14. acquiring the point cloud by irradiating light horizontally onto a surrounding space that includes the loading space and is wider in the horizontal direction than the loading space; 10. The position identification method according to claim 9, wherein an area on the X-axis with substantially no power adjacent to the center of the loading space of the most extreme area among areas with multiple powers is identified as the loading space, and the position of a section of the most extreme area with a power equal to or greater than a predetermined value is identified as a position related to the loading position of the transport vehicle.

15. a point cloud acquisition unit that horizontally irradiates light onto the loading space to acquire a point cloud; A program used in a transport vehicle equipped with a computer, The computer, Analyzing the acquired point cloud using a frequency distribution with the distance in the X-axis direction as an axis; Identifying a region with substantially no frequency as a storage space based on the analysis result of the point cloud; and identifying a section adjacent to the loading space having a frequency equal to or greater than a predetermined frequency as the position of an edge in the X-axis coordinate of an object adjacent to the loading space.

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