Automated transport system and information processing method

Abstract

To provide an automatic conveyance system that improves the accuracy of automatic travel of an automatic conveyance vehicle.SOLUTION: An automatic conveyance system includes a laser ranging sensor and an information processing device. The information processing device includes: an acquisition unit that acquires, from the laser ranging sensor, measurement data measured by a first direction vector of a scanning line of a laser beam and the scanning line of the laser beam; a calculation unit that calculates an angle θ formed between the first direction vector and a second direction vector of a line connecting two adjacent measurement data; a determination unit that determines whether or not the formed angle θ satisfies a predetermined condition; a first noise identification unit that identifies measurement data at a position farther from the laser ranging sensor as first noise data among the two adjacent measurement data; a second noise identification unit that identifies measurement data within a predetermined range from a position of the laser ranging sensor as second noise data; and a map generation unit that generates a two-dimensional map based on measurement data obtained by excluding the first noise data and the second noise data.SELECTED DRAWING: Figure 1

Description

【Technical Field】 【0001】 One embodiment of the present invention relates to an automatic transport system using an automatic transport vehicle. Another embodiment of the present invention relates to an information processing method for generating a two-dimensional map used in the automatic driving of an automatic transport vehicle. 【Background Art】 【0002】 In recent years, the technological development of automatic guided vehicles (AGVs) has advanced, and attempts have been made to introduce automatic transport vehicles that dive under a cart loaded with materials at a construction site and transport the cart. An automatic transport vehicle can detect obstacles in front of the vehicle by mounting a laser-type distance measuring sensor using laser light such as a laser range finder. However, when the scanning line of the laser light passes near the edge of an obstacle, a so-called multi-echo may occur due to the received light of the reflected light of the obstacle and the reflected light of an obstacle existing further behind. In this case, measurement data as if an obstacle exists is acquired at a location where there is actually no obstacle. Such measurement data due to multi-echo is so-called noise data. For example, Patent Document 1 discloses a method for identifying noise data from measurement data. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 Japanese Patent Application Laid-Open No. 2018-151315 【Summary of the Invention】 【Problems to be Solved by the Invention】 【0004】 In automated guided vehicles (AGVs) that move under the platform of a trolley to transport it, the trolley's casters are within the scanning range of the laser beam, and these casters act as obstacles, resulting in the acquisition of measurement data that always contains noise. In this case, the AGV 100 has to navigate automatically based on a 2D map that contains a lot of noise data, which leads to the problem of low accuracy in the AGV 100's automatic navigation. 【0005】 One embodiment of the present invention aims to provide an automated transport system that improves the accuracy of automated transport vehicle operation in view of the above problems. Another embodiment of the present invention aims to provide an information processing method that can generate a two-dimensional map with improved accuracy in the process of generating a two-dimensional map used for automated transport vehicle operation. [Means for solving the problem] 【0006】 An automated transport system according to one embodiment of the present invention includes an automated transport vehicle equipped with a laser-type distance measuring sensor capable of scanning laser light in a direction parallel to the floor surface, and an information processing device that is communicatively connected to the laser-type distance measuring sensor. The information processing device includes an acquisition unit that acquires a first direction vector of the scanning line of the laser light and measurement data measured by the scanning line of the laser light from the laser-type distance measuring sensor, a calculation unit that calculates a second direction vector of a line connecting two adjacent measurement data points and calculates the angle θ between the first direction vector and the second direction vector, and the information processing device that determines whether the angle θ satisfies predetermined conditions. The system includes a determination unit that determines whether or not noise is present, a first noise identification unit that, when the angle θ between the noises satisfies predetermined conditions, identifies the measurement data located further away from the laser distance measuring sensor as the first noise data, a second noise identification unit that identifies the measurement data located within a predetermined range from the position of the laser distance measuring sensor as the second noise data, and a map generation unit that generates a two-dimensional map based on the measurement data excluding the first and second noise data, wherein the predetermined conditions are 0 degrees or more and α degrees or (180-α) degrees or more and 180 degrees or less. 【0007】 An information processing method according to one embodiment of the present invention acquires a first direction vector of the scanning line of a laser beam and measurement data measured by the scanning line of a laser beam from a laser distance sensor equipped on an automated guided vehicle that is capable of scanning a laser beam in a direction parallel to the floor surface, calculates a second direction vector of a line connecting two adjacent measurement data points, calculates the angle θ between the first direction vector and the second direction vector, and when the angle θ is between 0 degrees and α degrees or between (180-α) degrees and 180 degrees, identifies the measurement data point further away from the laser distance sensor as the first noise data point, identifies the measurement data point within a predetermined range from the position of the laser distance sensor as the second noise data point, and generates a two-dimensional map based on the measurement data excluding the first noise data point and the second noise data point. 【0008】 α may be between 0 and 15 (inclusive). 【0009】 The predetermined range may be set based on the position of the casters of the trolley connected to the automated guided vehicle and the position of the laser rangefinder. [Effects of the Invention] 【0010】 According to an automated guided vehicle (AGV) system of one embodiment of the present invention, the AGV can travel based on a 2D map from which noise data has been removed, enabling highly accurate and stable automated travel. As a result, the range of applications for AGVs can be expanded. [Brief explanation of the drawing] 【0011】 [Figure 1] This is a schematic diagram showing the configuration of an automated transport system according to one embodiment of the present invention. [Figure 2] This is a block diagram showing a part of the configuration of an automated guided vehicle in an automated guided vehicle system according to one embodiment of the present invention. [Figure 3] This is a flowchart illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Figure 4]This is a schematic diagram illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Figure 5] This is a schematic diagram illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Figure 6] This is a schematic diagram illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Figure 7] This is a schematic diagram illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Figure 8] This is a schematic diagram illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Figure 9] This is a schematic diagram illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. [Modes for carrying out the invention] 【0012】 The embodiments of the present invention will be described below with reference to the drawings. It should be noted that these embodiments are merely examples, and any modifications that a person skilled in the art could easily conceive while maintaining the spirit of the invention are naturally included within the scope of the present invention. Furthermore, in order to clarify the explanation, the drawings may schematically represent the width, thickness, shape, etc., of each part compared to the actual embodiment. However, the illustrated shapes are merely examples and do not limit the interpretation of the present invention. 【0013】 In this specification, for the sake of clarity, terms such as "upper," "upper," or "upper part," or "lower," "lower," or "lower part" are used, but these merely describe the hierarchical relationship of each component. For example, when describing the positional relationship of the components of a structure (e.g., a trolley or automated guided vehicle), the side on which the structure is installed (e.g., the floor side) may be referred to as "lower," "lower," or "lower part," based on the normal mode of use of the structure. 【0014】 In this specification, the characters "first", "second", or "third" appended to each component are for convenience of distinction between the components and have no further meaning unless otherwise specified. 【0015】 In this specification and the drawings, when collectively representing a plurality of identical or similar components, the same reference numerals are used, and when separately representing each of these plurality of components, alphabetic characters in upper or lower case may be appended for representation. Further, when separately representing a plurality of parts within one component, hyphens and natural numbers may be used. 【0016】 In this specification, the "automated guided vehicle" refers to a vehicle that can automatically travel while transporting goods to a designated predetermined location. 【0017】 [1. Configuration of Automated Guided Vehicle System 10] [[ID=十六]]Fig. 1 is a schematic diagram showing the configuration of an automated guided vehicle system 10 according to an embodiment of the present invention. Specifically, Figs. 1(A) and 1(B) are respectively a front view and a top view of the automated guided vehicle system 【0018】 As shown in FIGS. 1(A) and 1(B), the automatic transport system 10 includes an automatic transport vehicle 100 and a cart 200. The automatic transport vehicle 100 includes a main body 110, a pair of crawlers 120, a laser distance measuring sensor 130, an information processing device 140, and a coupler 150. The pair of crawlers 120 is installed on the side surface of the main body 110. The laser distance measuring sensor 130 and the information processing device 140 are installed on the front surface of the main body 110. Note that the information processing device 140 may be housed inside the main body 110. The information processing device 140 is communicably connected to the laser distance measuring sensor 130, and can control the laser distance measuring sensor 130 or acquire data from the laser distance measuring sensor 130. The coupler 150 is installed on the upper surface of the main body 110. The cart 200 includes a loading platform 210, casters 220, and a coupler 230. The casters 220 and the coupler 230 are arranged on the bottom surface of the loading platform 210. 【0019】 The automatic transport vehicle 100 can be connected to the cart 200 by diving under the loading platform 210 of the cart 200 and engaging the coupler 150 with the coupler 230. Although not shown, the coupler 150 is connected to a lifting drive unit housed inside the main body 110, and can perform a lifting operation by the lifting drive unit. Therefore, in the automatic transport system 10, the coupler 150 can be lifted to lift the cart 200. Also, in the automatic transport system 10, the automatic transport vehicle 100 can automatically travel with the cart 200 lifted, and the automatic transport vehicle 100 can transport the cart 200 to a predetermined location. For example, materials used at a construction site can be loaded on the loading platform 210 of the cart 200, and the automatic transport system 10 can transport the materials to a predetermined location. Note that inside the main body 110, not only the above-described lifting drive unit but also a crawler drive unit that drives the crawlers 120 and a battery etc. may be housed. By mounting a battery on the automatic transport vehicle 100, power can be supplied to the information processing device 140, the lifting drive unit, or the crawler drive unit etc. of the automatic transport vehicle 100. 【0020】 The automated guided vehicle 100 can move by rotating a pair of crawlers 120. When the pair of crawlers 120 are rotated in the same direction, the automated guided vehicle 100 can move forward or backward. When the pair of crawlers 120 are rotated in different directions, the automated guided vehicle 100 can rotate in its current position. 【0021】 The automated guided vehicle (AGV) 100 is not limited to the above configuration. For example, the AGV 100 may include wheels instead of the pair of crawlers 120. Also, the AGV 100 may tow the trolley 200 using the casters 220 of the trolley 200 without lifting the trolley 200. Furthermore, the AGV 100 may include a plurality of laser-type distance measuring sensors 130, which may be installed not only on the front of the main body 110 but also on the rear. The laser-type distance measuring sensors 130 can also be installed in the gap between the main body 110 and the coupler 150. In the automated transport system 10, the information processing method described later can be applied regardless of where the laser-type distance measuring sensors 130 are installed, and a 2D map of the 360 ​​degrees around the AGV 100 can be generated. 【0022】 The laser distance sensor 130 is positioned in front of the automated guided vehicle 100 and projects laser scanning lines in a fan shape in the XY plane (a plane parallel to the floor) toward the front of the automated guided vehicle 100, measuring the distance to a structure in front of the automated guided vehicle 100 for each scanning line. Therefore, the automated transport system 10 can use the laser distance sensor 130 to detect obstacles and other structures in front of the automated guided vehicle 100. The laser distance sensor 130 is, for example, a laser rangefinder, but is not limited to this. 【0023】 The information processing device 140 is a so-called computer capable of performing arithmetic operations using information or data. The information processing device 140 includes, for example, a central processing unit (CPU), a microprocessor (MPU), or an image processing device (GPU), random access memory (RAM), read-only memory (ROM), flash memory, a storage device such as a hard disk drive (HDD), or a solid state drive (SSD), or a communication interface. 【0024】 As described above, the automated guided vehicle 100 can be connected to a trolley 200 and transport the trolley 200. The automated guided vehicle 100 detects obstacles in front of it using a laser distance sensor 130, but as shown in Figure 1(B), the casters 220 are within the scanning range of the laser beam of the laser distance sensor 130, so the casters 220 are also detected as obstacles. Furthermore, if there is an obstacle behind the casters 220, noise data is generated near the casters 220 due to multi-echo. Therefore, the automated transport system 10 uses an information processing device 140 to perform information processing to remove noise data from the casters 220 and noise data caused by the casters 220, thereby improving the accuracy of the 2D map used by the automated guided vehicle 100 when it is traveling. 【0025】 Figure 2 is a block diagram showing a part of the configuration of an automated guided vehicle 100 of an automated guided vehicle system 10 according to one embodiment of the present invention. Figure 2 shows a laser distance measuring sensor 130 and an information processing device 140 as configurations related to the two-dimensional map generation process described later. By executing a program, the information processing device 140 can realize an acquisition unit 141, a calculation unit 142, a determination unit 143, a first noise identification unit 144, a second noise identification unit 145, and a map generation unit 146, as shown in Figure 2. 【0026】 The acquisition unit 141 communicates with the laser distance measuring sensor 130 and can acquire multiple measurement data from the laser distance measuring sensor 130. The acquisition unit 141 may acquire the measurement data generated by the laser distance measuring sensor 130 as is, or it may acquire data converted from the measurement data generated by the laser distance measuring sensor 130 as measurement data. For example, if the measurement data generated by the laser distance measuring sensor 130 does not include the first direction vector of the laser beam scan line, the acquisition unit 141 can convert the measurement data generated by the laser distance measuring sensor 130 to acquire the first direction vector of the laser beam scan line. The acquisition unit 141 preferably acquires measurement data having XY coordinates, but is not limited to this. 【0027】 The calculation unit 142 can extract two adjacent measurement data points from the multiple measurement data acquired by the acquisition unit 141, and calculate a second direction vector of the line (straight line) connecting the two extracted data points. The calculation unit 142 can also calculate the angle θ between the first direction vector of one or both of the scan lines of the two measurement data points used in the calculation of the second direction vector and the calculated second direction vector. 【0028】 The determination unit 143 can determine whether the angle θ between the first direction vector and the second direction vector satisfies a predetermined condition. The predetermined condition is, for example, 0 degrees or more and α degrees or (180-α) degrees or more and 180 degrees or less. Here, α is an arbitrary set value, for example, α is 0 or more and 15 or less, preferably 0 or more and 5 or less. If α is large, measurement data other than noise data will be excluded, so it is preferable that α is within the above range. Note that the predetermined condition is not limited to the above condition, as it is a condition that allows noise data to be identified using the angle θ between the first direction vector and the second direction vector. 【0029】 The first noise identification unit 144 can identify the measurement data located further away from the laser distance measuring sensor 130 as the first noise data among the two measurement data used in calculating the second direction vector, when the angle θ between the first direction vector and the second direction vector satisfies a predetermined condition. 【0030】 The second noise identification unit 145 can identify measurement data within a predetermined range as second noise data. The predetermined range can be set in advance; for example, the range up to a certain distance from the laser distance sensor 130 can be set as the predetermined range. Preferably, the predetermined range includes the structure of the object being transported by the automated guided vehicle 100 during automatic travel (for example, the casters 220 of the trolley 200), but is not limited to this. The predetermined range may be more than one range. Furthermore, the predetermined range may be set based on a location other than the position of the laser distance sensor 130. 【0031】 The map generation unit 146 can remove first noise data and second noise data from multiple measurement data acquired by the acquisition unit 141 and generate a two-dimensional map that does not contain the first noise data and second noise data. The two-dimensional map generated by the map generation unit 146 is a highly accurate two-dimensional map because much of the noise data has been removed. In addition, because the second noise data caused by the structure of the transported object has been removed, the automated guided vehicle 100 can operate with high accuracy and stability when transporting the transported object. 【0032】 [2. Information processing performed in the automated transport system 10] Referring to Figures 3 to 9, the information processing performed in the automated guided vehicle system 10 will be further explained. Specifically, the process for generating a 2D map used in the automated driving of the automated guided vehicle 100 will be described below. 【0033】 Figure 3 is a flowchart illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. Figures 4 to 9 are schematic diagrams illustrating the process of generating a two-dimensional map performed in an automated transport system 10 according to one embodiment of the present invention. In the following explanation of the flowchart in Figure 3, we will refer to Figures 4 to 9 as appropriate. Figures 4 to 9 show a laser distance measuring sensor 130, a scan line 131 of the laser beam emitted from the laser distance measuring sensor 130, a first structure 500-1, and a second structure 500-2. The first structure 500-1 is a structure of an object to be transported by the automated transport vehicle 100, specifically a caster 220 of a trolley 200. The second structure 500-2 is an obstacle that hinders the automatic movement of the automated transport vehicle 100. 【0034】 As shown in Figure 3, in the 2D map generation process of the automated transport system 10, steps S110 to S170 are executed in order. However, the 2D map generation process is not limited to steps S110 to S170 and may include other steps. 【0035】 In step S110, the acquisition unit 141 acquires the first direction vector of the laser beam scan line 131 and the measurement data 132 measured by the scan line 131 from the laser distance sensor 130 (see Figure 4). Since the measurement data 132 is acquired as data indicating an object in each of the multiple scan lines 131, the acquisition unit 141 can acquire measurement data as an object. The measurement data 132 may be XY coordinate data or distance data. If the measurement data 132 is XY coordinate data, the first direction vector can also be acquired based on the XY coordinates. Even if the measurement data 132 is distance data, the distance data can be converted to XY coordinates based on the first direction vector of the scan line 131 and the distance data, so that a two-dimensional map in the XY plane as shown in Figure 4 can be generated. For this reason, the following explanation assumes that the measurement data 132 has XY coordinates. In Figure 4, the measurement data 132 is shown as black circles. 【0036】 In step S120, the calculation unit 142 calculates a second direction vector of the line connecting two adjacent measurement data points of the laser beam scan line (see Figure 5). 【0037】 In step S130, the calculation unit 142 calculates the angle θ between the first direction vector of the scan line used in step S120 and the second direction vector calculated in step S120 (see Figure 6). The first direction vector may be either one of the two scan lines 131 that measured two adjacent measurement data 132, or the angle θ between the two may be calculated using the first direction vectors of both scan lines 131. 【0038】 In step S140, the determination unit 143 determines whether the angle θ between the first direction vector and the second direction vector satisfies a predetermined condition. The predetermined condition is that it is 0 degrees or more and α degrees or (180-α) degrees or more and 180 degrees or less. When the angle θ between the first direction vector and the second direction vector satisfies the above condition, it indicates that the line connecting two adjacent measurement data points and the scan line 131 are nearly parallel. When the angle θ between the first direction vector and the second direction vector satisfies the above condition (step S140: YES), step S150 is executed. When the angle θ between the first direction vector and the second direction vector does not satisfy the above condition (step S140: NO), step S160 is executed. 【0039】 In step S150, the first noise identification unit 144 identifies the measurement data 132 located further away from the laser distance measuring sensor 130 from two adjacent measurement data 132 whose angle θ between the first direction vector and the second direction vector satisfies the above condition as the first noise data 133 (see Figure 7). The first noise identification unit 144 compares the distance data of the two adjacent measurement data 132 and identifies one of the measurement data 132 as the first noise data 133. In Figure 7, the first noise data 133 is shown as a white circle. As can be seen from Figure 7, the first noise data 133 is noise data originating from the edge of the first structure 500-1. 【0040】 In step S160, the second noise identification unit 145 identifies the measurement data 132 that exists within a predetermined range β as the second noise data 134 (see Figure 8). For example, as shown in Figure 8, the predetermined range β can be set to a semicircular range with a predetermined radius centered on the position of the laser distance measuring sensor 130. The predetermined range β is set to include the first structure 500-1. In Figure 8, the second noise data 134 is shown as a white circle. As can be seen from Figure 8, the second noise data 134 is noise data originating from the first structure 500-1 itself. 【0041】 In step S170, the map generation unit 146 generates a two-dimensional map by excluding the first noise data 133 identified in step S150 and the second noise data 134 identified in step S160 from the measurement data 132 acquired in step S110 (see Figure 9). As shown in Figure 9, the measurement data caused by the first structure 500-1 near the laser distance sensor 130 is excluded, and a two-dimensional map is generated that includes only the measurement data 132 of the second structure 500-2, which is the actual obstacle. In other words, a two-dimensional map with less noise data is generated. When step S170 is executed, the two-dimensional map generation process is completed. 【0042】 As described above, the automated transport system 10 according to this embodiment can generate a highly accurate two-dimensional map that excludes noise data caused by the structure of the transported object and includes only measurement data based on the actual obstacles. Furthermore, since the automated guided vehicle 100 uses the two-dimensional map generated by the automated transport system 10, the automated guided vehicle 100 can perform highly accurate and stable automated driving. Therefore, the applications for which the automated guided vehicle 100 can be applied can be expanded beyond construction sites. 【0043】 The embodiments described above as embodiments of the present invention can be combined and implemented as appropriate, insofar as they do not contradict each other. Furthermore, any additions, deletions, or design changes to components, or additions, omissions, or changes to processes based on these embodiments, made by those skilled in the art, are also included within the scope of the present invention, as long as they retain the essence of the present invention. 【0044】 Any effects or benefits other than those brought about by the embodiments described above, if they are clear from the description herein or can be easily predicted by those skilled in the art, are naturally considered to be brought about by the present invention. [Explanation of symbols] 【0045】 10: Automated transport system, 100: Automated transport vehicle, 110: Main unit, 120: Crawler, 130: Laser distance sensor, 131: Scanning line, 132: Measurement data, 133: First noise data, 134: Second noise data, 140: Information processing device, 141: Acquisition unit, 142: Calculation unit, 143: Judgment unit, 144: First noise identification unit, 145: Second noise identification unit, 146: Map generation unit, 150: Coupler, 200: Trolley, 210: Loading platform, 220: Caster, 230: Coupler, 500-1: First structure, 500-2: Second structure

Claims

[Claim 1] An automated guided vehicle is equipped with a laser-type distance measuring sensor capable of scanning a laser beam parallel to the floor surface, The system includes an information processing device that is communicatively connected to the laser-type distance measuring sensor, The aforementioned information processing device is An acquisition unit that acquires a first direction vector of the scanning line of the laser beam and measurement data measured by the scanning line of the laser beam from the laser distance measuring sensor, A calculation unit calculates a second direction vector of the line connecting two adjacent measurement data points and calculates the angle θ between the first direction vector and the second direction vector, A determination unit that determines whether the angle θ meets a predetermined condition, When the angle θ satisfies a predetermined condition, a first noise identification unit identifies the measurement data at the position further away from the laser distance measuring sensor among the two adjacent measurement data as first noise data, A second noise identification unit identifies the measurement data within a semicircular area having a predetermined radius centered on the position of the laser-type distance measuring sensor as second noise data, The system includes a map generation unit that generates a two-dimensional map based on the measurement data excluding the first noise data and the second noise data, An automated transport system in which the aforementioned predetermined conditions are 0 degrees or more and α degrees or (180-α) degrees or more and 180 degrees. [Claim 2] The automatic transport system according to claim 1, wherein α is 0 or more and 15 or less. [Claim 3] From a laser-type distance measuring sensor equipped in an automated guided vehicle, which is capable of scanning a laser beam parallel to the floor surface, a first direction vector of the scanning line of the laser beam and measurement data measured by the scanning line of the laser beam are acquired. The second direction vector of the line connecting two adjacent measurement data points is calculated. The angle θ between the first direction vector and the second direction vector is calculated, When the angle θ is between 0 degrees and α degrees or between (180-α) degrees and 180 degrees, the measurement data at the position further away from the laser distance measuring sensor among the two adjacent measurement data is identified as the first noise data. The measurement data located within a semicircular area having a predetermined radius centered on the position of the laser-type distance measuring sensor is identified as second noise data. An information processing method for generating a two-dimensional map based on the measurement data from which the first noise data and the second noise data have been excluded. [Claim 4] The information processing method according to claim 3, wherein α is 0 or more and 15 or less.

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