Three dimensional map generation system, generation method, and program thereof

Abstract

To provide a three dimensional map generation method capable of generating a three dimensional map even in a closed space surrounded on all sides by a structure.SOLUTION: Since the markers are installed at predetermined arrangement intervals on the surface of the structure in the closed space, when the distance measurement unit measures the distance and direction between the structure and the markers, the markers are included in the measurement range of the distance measurement unit. With this configuration, it is possible to provide a method for generating a three dimensional map including a range that cannot be measured from the first position by combining the point cloud data at the first position and the point cloud data at the second position with reference to the information regarding the position of the marker included in the first distance information obtained at the first position and the information regarding the position of the marker included in the second distance information obtained at the second position.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a three-dimensional map generation system, a generation method, and a program therefor. [Background technology]

[0002] Conventionally, methods and devices for real-time mapping analysis, localization analysis, and change analysis, particularly in environments where GPS is unavailable, have been known. For example, Patent Document 1 describes a method for constructing a 3D reference map that can be used in real-time mapping analysis, localization analysis, and change analysis, where the 3D reference map is created using a 3D SLAM (simultaneous localization and mapping) framework based on a mobile laser range scanner, and a mobile laser scanning device for realizing the method. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-198517 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the method described in Patent Document 1 has the problem that it is not possible to generate an accurate three-dimensional map when used in a closed space surrounded on all sides by structures with little change in the surface, such as a sewer.

[0005] The present invention has been made in consideration of these problems, and its main object is to provide a 3D map generation method that can generate a 3D map even for a closed space surrounded on all sides by structures. Another object is to provide a 3D map generation system and program therefor that can generate a 3D map even for a closed space surrounded on all sides by structures. [Means for solving the problem]

[0006] In order to achieve at least one of the above-mentioned objects, the present invention employs the following means.

[0007] A first aspect of a 3D map generation method according to the present invention comprises: A three-dimensional map generation method in which a moving body moving from a first position to a second position moves in a closed space surrounded on all sides by a structure having a plurality of markers set at a predetermined interval on its surface, and a three-dimensional map is generated using information about distances measured by distance measurement means provided on the moving body and measuring distances from the moving body to the surfaces of the structure and the markers, a first distance information acquisition step of acquiring, when the moving body is located at the first position, first distance information measuring a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers; a second distance information acquisition step of acquiring second distance information that measures a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers when the moving body is located at the second position; a combining step of combining first point cloud data indicating the positions of the structure and the marker derived from the first distance information based on information indicating the distance and direction to the surface of the marker, which is included in the first distance information, and second point cloud data indicating the positions of the structure and the marker derived from the second distance information based on information indicating the distance and direction to the surface of the marker, which is included in the second distance information; Including, It is something.

[0008] This three-dimensional map generation method generates a three-dimensional map based on information about the distance and direction from a moving object to the surfaces of the structures and markers placed at a predetermined interval on the surface of the structures. Specifically, first distance information is acquired, which is information about the distance from the moving object to the surfaces of the structures and markers when the moving object is located at a first position, and first point cloud data indicating the positions of the structures and markers is derived based on the first distance information. Next, second distance information is acquired, which is information about the distance from the moving object to the surfaces of the structures and markers when the moving object is located at a second position, and second point cloud data indicating the positions of the structures and markers is derived based on the second distance information. The three-dimensional map is then generated by combining the first point cloud data and the second point cloud data. In this way, by combining the first point cloud data and the second point cloud data, a three-dimensional map can be generated even for areas that cannot be measured from the first position. At this time, for example, in the case of an enclosed space surrounded on all sides by structures, there is little change in the surface of the structures, making it difficult to combine the first point cloud data and the second point cloud data at the correct position. However, in this 3D map generation method, markers are placed on the surface of the structure at intervals equal to or less than a predetermined placement interval, so that information about the markers is included in both the first point cloud data and the second point cloud data. This allows the markers to become feature points in the data, and the first point cloud data and the second point cloud data to be accurately combined, making it possible to generate a 3D map even within a closed space. Here, the "predetermined placement interval" means that adjacent markers are all spaced at the same interval, and also means that even if the spacing between adjacent markers is different, it is still within a predetermined range.

[0009] A second aspect of the method for generating a three-dimensional map according to the present invention comprises: A three-dimensional map generation method in which a moving body moving from a first position to a second position moves in a closed space surrounded on all sides by a structure having a plurality of markers set at a predetermined interval on its surface, and a three-dimensional map is generated using information about distance measured by a distance measurement means provided on the moving body and measuring the distance from the moving body to the surface of the structure and the markers, and information about movement of the moving body acquired by a movement detection means provided on the moving body and measuring information about the movement of the moving body, a first distance information acquisition step of acquiring, when the moving body is located at the first position, first distance information measuring a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers; a second distance information acquisition step of acquiring second distance information that measures a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers when the moving body is located at the second position; a relative position calculation step of calculating a relative position of the second position with respect to the first position based on information about the movement of the moving object acquired by the movement detection means; a combining step of combining the first point cloud data and the second point cloud data based on the relative position of the second position calculated in the relative position calculating step, first point cloud data indicating the positions of the structure and the marker derived from the first distance information based on information indicating the distance and direction to the surface of the marker included in the first distance information, and second point cloud data indicating the positions of the structure and the marker derived from the second distance information based on information indicating the distance and direction to the surface of the marker included in the second distance information; The purpose is to include It is something.

[0010] This three-dimensional map generation method generates a three-dimensional map based on information regarding the distance and direction from a moving object to the surfaces of the structures and markers placed at a predetermined interval on the surfaces of the structures, and on changes in the position of the moving object. Specifically, first distance information is acquired, which is information regarding the distance from the moving object to the surfaces of the structures and markers when the moving object is located at a first position, and first point cloud data indicating the positions of the structures and markers is derived based on the first distance information. Next, second distance information is acquired, which is information regarding the distance from the moving object to the surfaces of the structures and markers when the moving object is located at a second position, and second point cloud data indicating the positions of the structures and markers is derived based on the second distance information. In addition, the relative position of the second position with respect to the first position is calculated based on information regarding the movement of the moving object acquired by a movement detection means. Then, the first point cloud data and the second point cloud data are combined based on the relative position of the second position to generate a three-dimensional map. In this way, by combining the first point cloud data and the second point cloud data, a three-dimensional map can be generated even for areas that cannot be measured from the first position. In this case, for example, in the case of a closed space surrounded by structures on all sides, the surface of the structure is not significantly changed, making it impossible to combine the first point cloud data and the second point cloud data at the correct positions. However, in this 3D map generation method, markers are placed on the surface of the structure at intervals equal to or less than a predetermined spacing, so that both the first point cloud data and the second point cloud data contain information about the markers. This allows the markers to become feature points in the data, enabling the first point cloud data and the second point cloud data to be accurately combined, thereby generating a 3D map even within a closed space. In this case, changes in the relative positions of the first point cloud data and the second point cloud data can be calculated based on changes in the relative positions of the first position and the second position, making it possible to generate a more accurate 3D map compared to when the relative positions of the first position and the second position are not known.

[0011] A third aspect of the method for generating a 3D map according to the present invention is the first or second aspect, wherein the predetermined placement interval may be shorter than a measurement distance that can be measured by the distance measurement means. This ensures that at least one marker is included in the measurement range of the distance measurement means, making it possible to generate a 3D map more accurately.

[0012] A fourth aspect of the map generation method according to the present invention is any of the first to third aspects, wherein the predetermined placement interval is between 0.4 meters and 10 meters. A predetermined placement interval of more than 10 meters is not preferred because the markers do not adequately function as feature points on the surface of the structure. On the other hand, a predetermined placement interval of less than 0.4 meters is not preferred because there are too many markers and the distance to the surface of the structure cannot be adequately measured.

[0013] A fifth aspect of the map generation method according to the present invention is any of the first to fourth aspects, wherein the marker has a hemispherical shape with a diameter of 100 mm to 1000 mm. Markers with a diameter of less than 100 mm are not preferred because they may not be able to be measured sufficiently.

[0014] The program of the present invention is a program for causing one or more computers to execute each step of the 3D map generation method of the first to fifth aspects. This program may be recorded on a computer-readable storage medium (e.g., a hard disk, ROM, CD, DVD, flash memory, etc.), may be transmitted from one computer to another via a transmission medium (a communication network such as the Internet or a wired / wireless LAN), or may be transmitted in any other form. Furthermore, even if the program is executed by a device that executes each step of the 3D map generation method, the device on which the program is executed may be different from the device on which the processing is performed. In either case, by executing this program on a single computer or by having multiple computers share and execute each step, it is possible to obtain the same effects as the above-mentioned 3D map generation method.

[0015] The three-dimensional map generation system of the present invention comprises: A three-dimensional map generation system in which a mobile object moving from a first position to a second position moves in a closed space surrounded on all sides by a structure having a plurality of markers set at predetermined intervals on its surface, and a three-dimensional map is generated using information about distances measured by distance measurement means provided on the mobile object and measuring distances from the mobile object to the surfaces of the structure and the markers, an information acquisition means for acquiring first distance information that measures the distance and direction from the moving body to the surface of at least one of the structure and the plurality of markers when the moving body is located at the first position, and second distance information that measures the distance and direction from the moving body to the surface of at least one of the structure and the plurality of markers when the moving body is located at the second position; a combining means for combining first point cloud data indicating the positions of the structure and the marker derived from the first distance information based on information indicating the distance and direction to the surface of the marker, which is included in the first distance information, and second point cloud data indicating the positions of the structure and the marker derived from the second distance information based on information indicating the distance and direction to the surface of the marker, which is included in the second distance information; The purpose is to provide It is something.

[0016] This three-dimensional map generation system generates a three-dimensional map based on information about the distance and direction from a moving object to the surfaces of the structures and markers placed at a predetermined interval on the surface of the structures. Specifically, the system acquires first distance information, which is information about the distance from the moving object to the surfaces of the structures and markers when the moving object is located at a first position, and derives first point cloud data indicating the positions of the structures and markers based on the first distance information. Next, the system acquires second distance information, which is information about the distance from the moving object to the surfaces of the structures and markers when the moving object is located at a second position, and derives second point cloud data indicating the positions of the structures and markers based on the second distance information. The system then generates a three-dimensional map by combining the first point cloud data and the second point cloud data. In this way, by combining the first point cloud data and the second point cloud data, a three-dimensional map can be generated even for areas that cannot be measured from the first position. In this case, for example, in an enclosed space surrounded by structures on all sides, there is little change in the surface of the structures, making it difficult to combine the first point cloud data and the second point cloud data at the correct positions. However, in this 3D map generation system, markers are placed on the surface of the structure at intervals equal to or less than a predetermined spacing, so that information about the markers is included in both the first point cloud data and the second point cloud data. This makes it possible to accurately combine the first point cloud data and the second point cloud data, making it possible to generate a 3D map even in a closed space. [Brief explanation of the drawings]

[0017] [Figure 1] FIG. 1 is a block diagram showing the electrical connections of a 3D map generation system 20. [Figure 2] FIG. 2 is an explanatory diagram for explaining the inner surface (side surface) of the structure 12. As shown in FIG. [Figure 3] FIG. 3 is a flowchart showing an example of a three-dimensional map generating method. [Figure 4] FIG. 4 is an explanatory diagram showing an example of a three-dimensional map generation method. [Figure 5] FIG. 5 is a block diagram showing the electrical connections of the 3D map generation system 120. [Figure 6] FIG. 6 is a flowchart showing an example of a 3D map generating method according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0018] Next, as an example of an embodiment of the present invention, a 3D map generation system 20 will be described in detail with reference to the drawings. Note that by describing a method for generating a 3D map using the 3D map generation system 20, an example of a 3D map generation method and a 3D map generation program of the present invention will also be clarified.

[0019] The embodiments and drawings described below illustrate examples of embodiments of the present invention and are not intended to limit the scope of the invention. The novel embodiments described below can be implemented in various other forms, and various omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. The following embodiments and their variations are within the scope and spirit of the invention, and are also within the scope of the inventions described in the claims and their equivalents. Note that corresponding components in each drawing are designated by the same or similar symbols.

[0020] 1, a three-dimensional map generation system 20, which is an example of an embodiment of the present invention, includes a mobile object 22 that moves within a closed space to acquire various types of data, and an information processing device 30 that generates a three-dimensional map based on the various types of information output from the mobile object 22, and the mobile object 22 and the information processing device 30 are electrically connected via a wireless communication line. In this three-dimensional map generation system 20, the various types of data acquired by the mobile object 22 are transmitted to the information processing device 30, and the information processing device 30 generates a three-dimensional map based on the various types of data.

[0021] As shown in FIG. 2, the mobile object 22 is movably installed on the floor of a closed space 10 surrounded on all sides by a structure 12 having markers 14 provided at predetermined positions. An operator (not shown) transports the closed space 10, causing the mobile object 22 to move within the closed space 10. As shown in FIG. 1, the mobile object 22 is equipped with a distance measurement unit 26 that measures the distance and direction from the mobile object 22 to the surfaces of the structure 12 and the markers 14, and an output unit 28 that outputs information about the distance and direction measured by the distance measurement unit 26. As the mobile object 22 moves, the distance measurement unit 26 measures the distance and direction to the surfaces of the structure 12 and the markers 14. In this manner, as the mobile object 22 moves, information measuring the distance and direction from the mobile object 22 to the surfaces of the structure 12 and the markers 14 can be obtained for each position of the mobile object 22, based on the initial position of the mobile object 22. The information obtained in this manner is transmitted to an information processing device 30 via the output unit 28. Point cloud data is generated based on this information, and a three-dimensional map is generated. As the moving body 22, for example, Orbis manufactured by FARO can be used.

[0022] Here, the marker 14 is a white hemisphere with a diameter of approximately 100 mm. However, various shapes can be used as long as they have a predetermined area that reflects light differently from the surface of the structure 12. For example, a hemisphere or an approximate hemisphere with a diameter of 100 mm to 1000 mm is preferred, and a diameter of 200 mm to 800 mm is more preferred. A diameter of 100 mm or more is preferred because it allows the distance measurement unit 26 to reliably measure the marker 14 and makes it easy to distinguish from the surface irregularities of the structure 12, even if the surface has irregularities. Furthermore, the shape is not limited to a hemisphere and may be various shapes such as a rectangular parallelepiped or a cylindrical shape, or may be an object such as a chair or a desk, or even a person. The size is also not particularly limited, and various sizes can be selected as long as they are distinguishable from the irregularities on the surface of the structure 12. Furthermore, the marker 14 is not limited to a three-dimensional structure. For example, the marker 14 may be an approximately rectangular shape with a predetermined area painted white, or may have a light reflectance different from the surface of the structure 12. For example, the color is not limited to white, but may be red, black, or any other color that is different from the surface of the structure 12, and may be a combination of multiple colors such as red and white, or may be a single color. For example, if the surface of the structure 12 is white, it is preferable that the color has a different light reflectance from the surface of the structure 12, such as black.

[0023] The distance measurement unit 26 (the distance measurement unit 26 corresponds to the distance measurement means of the present invention) is, for example, a known distance measurement unit such as a laser distance measurement unit. This distance measurement unit 26 measures the distance and direction from the moving body 22 to the surface of the structure 12 and the marker 14 by irradiating light such as near-infrared light, visible light, or ultraviolet light onto the structure 12 and the marker 14 and capturing the reflected light with an optical sensor. By using a laser distance measurement unit 26 in this way, the distance and direction from the moving body 22 to the structure 12 or the marker 14 can be accurately measured. The measurement limit of this distance measurement unit 26 is a maximum radius of 10 meters.

[0024] The information processing device 30 is, for example, a known computer, and as shown in FIG. 1 , includes a control unit 32 that executes various programs including a 3D map generation routine, a memory unit 34 that stores various programs including the 3D map generation routine and various information transmitted from the mobile object 22, and a communication unit 36 ​​that receives various information output from the output unit 28 of the mobile object 22, and the control unit 32, the memory unit 34, and the communication unit 36 ​​are electrically connected via a bus 38. The information processing device 30 generates a 3D map based on information regarding the position and information regarding the distance output from the mobile object 22. The information processing device 30 may be in an on-premise configuration or in a cloud configuration. In the cloud configuration, the above-described functions and processes may be provided, for example, in the form of cloud computing.

[0025] The control unit 32 is, for example, a central processing unit (CPU), and realizes various functions of the information processing device 30 by reading out various programs stored in the storage unit 34. In other words, information processing by software stored in the storage unit 34 is specifically realized by the control unit 32, which is an example of hardware, and can be executed as each functional unit included in the control unit 32. Note that the control unit 32 is not limited to being a single unit, and may be implemented with multiple control units 32 for each function, or a combination thereof. The control unit 32 processes and controls the overall operations related to the information processing device 30, and executes various steps of a 3D map generation processing routine for generating a 3D map.

[0026] The memory unit 34 is, for example, a storage device such as a solid state drive (SSD) or a hard disk drive (HDD) that stores various programs executed by the control unit 32, or a memory such as a random access memory (RAM) that temporarily stores information regarding distance and direction output from the moving body 22.

[0027] The communication unit 36 ​​is a known communication means that receives information about distance and direction output from the output unit 28 of the moving object 22. The various information received by the communication unit 36 ​​is temporarily stored in the memory unit 34 via the bus 38.

[0028] Next, the flow of generating a three-dimensional map of a closed space 10 will be described. For example, the generation of a three-dimensional map of a place surrounded on all sides by structures 12 where there is little change in the surface of the structures 12, such as an underground facility such as a sewer, will be described. When generating a three-dimensional map of a closed space 10 surrounded on all sides by structures 12, markers 14 are placed in advance at predetermined intervals, and then the necessary information is acquired using a mobile object 22. Specifically, the process will be described using FIG. 2. Here, FIG. 2 is an explanatory diagram for explaining the inner surface (side surface) of the structure 12 of the closed space 10.

[0029] When generating a 3D map of a closed space 10, as shown in FIG. 2, multiple markers 14 are placed at a predetermined spacing in the closed space 10, which is surrounded on all four sides by structures 12. Here, the predetermined spacing is preferably 0.4 meters to 10 meters, and more preferably 0.4 meters to 5 meters. A spacing of 10 meters or less is preferable because the distance to the nearest marker 14 is 10 meters or less regardless of the position of the moving object 22, allowing the distance measurement unit 26 to reliably measure the distance to the marker 14. A spacing of 5 meters or less is more preferable because the distance measurement unit 26 can measure the distance to the marker 14 with high accuracy. Furthermore, a spacing of less than 0.4 meters is undesirable because it increases the number of areas where the distance to the structure 12 cannot be measured due to the markers 14, potentially reducing the accuracy of the 3D map. The term "predetermined spacing" refers not only to the fact that adjacent markers 14 are all spaced the same distance apart, but also to the fact that even if the spacing between adjacent markers 14 is different, it is still within the predetermined range. For example, the intervals between adjacent markers 14 may all be 10 meters, or the intervals between adjacent markers 14 may vary, such as 5 meters, 8 meters, or 10 meters, as long as they are all 10 meters or less.

[0030] Furthermore, the intervals between adjacent markers 14 may all be uniform or may differ. For example, if the interval between a first marker 14 and an adjacent second marker 14 is 10 meters, the interval between the second marker 14 and an adjacent third marker 14 may be 9 meters. Furthermore, the installation positions of adjacent markers 14 may all be the same height from the floor or may differ. For example, if a first marker 14 is installed at a height of 1 meter from the floor, an adjacent second marker 14 may be installed at a height of 2 meters from the floor. Furthermore, if a first marker 14 is installed on a wall on the right side facing the direction of travel, an adjacent second marker 14 may be installed on a wall on the left side facing the direction of travel, or an adjacent third marker 14 may be installed on the ceiling. In this way, by making the intervals, installation heights, locations, etc. between adjacent markers 14 different, the appearance positions of the markers 14 become monotonous, thereby reducing the possibility that they will no longer fulfill their role as markers. Furthermore, if the surface of the structure 12 has a distinctive shape, this shape may be used as a marker. For example, if there is a pillar with a diameter of 1 meter located 10 meters from the first marker 14, this pillar can be replaced with a second marker.

[0031] Next, the mobile object 22 is placed at a starting point where generation of the three-dimensional map begins, and a start switch (not shown) of the mobile object 22 is pressed, causing the distance measurement unit 26 to start measuring the distance and direction from the mobile object 22 to the surface positions of the structure 12 and the marker 14 in accordance with a control signal transmitted from the control unit 32 (step S110, see FIG. 3). At this time, the distance measurement unit 26 performs omnidirectional measurement (scanning), so that the distances and directions to the surfaces of the structure 12 and the marker 14 present in all directions around the mobile object 22 are measured, and information on the respective directions and distances is obtained.

[0032] Next, the control unit 32 sets the start point as a first position and transmits information regarding the distance and direction from the moving object 22 to the surface positions of the structures 12 and markers 14, which is acquired by the distance measurement unit 26 at the start point, as first distance information to the information processing device 30 (step S120). Next, the moving object 22 moves from the start point toward the end point, and at a second position a certain distance from the start point, the control unit 32 transmits information regarding the distance and direction from the moving object 22 to the surface positions of the structures 12 and markers 14, which is acquired by the distance measurement unit 26, as second distance information to the information processing device 30 (step S130). The moving object 22 repeats steps S120 and S130, moving back and forth from the start point to the end point and from the end point to the start point. At this time, the distance measurement unit 26 continues to measure the distances and directions to the surfaces of the structures 12 and markers 14, which exist in all directions around the moving object 22, so that information regarding continuous surface information of the surfaces of the structures 12 and markers 14 from the start point to the end point is obtained as the moving object 22 moves. The moving speed of moving body 22 is preferably 4 kilometers per hour or less, and more preferably 2 kilometers per hour or less. A moving speed faster than 4 kilometers per hour is not preferable because the measurements by distance measurement unit 26 may become discontinuous.

[0033] Next, the control unit 32 generates point cloud data based on the first distance information and the second distance information, and generates a three-dimensional map based on this point cloud data (step S140). As a method for generating the three-dimensional map, a known method for generating a three-dimensional map using point cloud data can be used. Here, an example of the method for generating a three-dimensional map will be described in detail with reference to FIG. 4. Here, FIG. 4 is an explanatory diagram showing an example of the method for generating a three-dimensional map.

[0034] As shown in FIG. 4(a), the control unit 32 generates point cloud data based on the first distance information and the second distance information. Next, as shown in FIG. 4(b), the control unit 32 combines the two point cloud data sets, using the positions corresponding to the markers 14 included in the point cloud data as reference positions. Because the moving object 22 measures the distances and directions to the surfaces of the structures 12 and markers 14 in all directions as it moves, the distance information obtained through the measurements partially overlaps. Therefore, by combining the distance information for the first and second positions based on the position of the markers 14, information covering a range greater than the distance that the distance measurement unit 26 can measure in one go can be integrated to generate a single three-dimensional map. While the first and second positions have been described here, a three-dimensional map covering the entire range from the initial position to the final position can be generated by repeating this process.

[0035] At this time, the mobile object 22 travels back and forth from the start point to the end point, so the same location is measured at least twice. By utilizing the overlap of these measurement positions, the movement of the mobile object 22 can be estimated from the overlap, and a continuous three-dimensional map from the start point to the end point can be generated. Note that various known methods using point cloud data can be used to generate the three-dimensional map. For example, when Orbis manufactured by FARO is used as the mobile object 22, the simultaneous localization and mapping (SLAM) technology installed in Orbis can be used.

[0036] When measuring an enclosed space 10 in which there is little change in the surface of the structure 12, it may be impossible to correctly recognize the overlap of the point cloud data. In such cases, the distance from the first position to the second position may not be correctly recognized, and the distance from the first position to the second position on the generated 3D map may be shorter than the actual distance from the first position to the second position. However, by providing markers 14 at a predetermined interval, the markers 14 become feature points, reducing the possibility of incorrectly recognizing the overlap of the point cloud data, and enabling the generation of a more accurate 3D map.

[0037] For example, if the enclosed space 10 is located underground, it is difficult to obtain location information using a GPS system and identify the location using this location information because radio waves have difficulty reaching the enclosed space 10. For this reason, it is very effective to use the marker 14 to correctly recognize the distance from the first location to the second location.

[0038] Next, a three-dimensional map generation system 120 as an example of another embodiment will be described with reference to Fig. 5. Here, Fig. 5 is a block diagram showing the electrical connections of the three-dimensional map generation system 120 of another embodiment. As shown in Fig. 5, this three-dimensional map generation system 120 includes a mobile object 122 that moves within a closed space to acquire various types of data, and an information processing device 30 that generates a three-dimensional map based on the various types of information output from the mobile object 122, and the mobile object 122 and the information processing device 30 are electrically connected via a wireless communication line. In this three-dimensional map generation system 120, the various types of data acquired by the mobile object 122 are transmitted to the information processing device 30, and the information processing device 30 generates a three-dimensional map based on the various types of data.

[0039] In the 3D map generation system 120 of this embodiment, the mobile object 122 includes a movement detection unit 124 that detects the movement of the mobile object 122, a distance measurement unit 26 that measures the distance and direction from the mobile object 122 to the structure 12, and an output unit 28 that outputs information related to the movement and direction detected by the movement detection unit 124 and information related to the distance measured by the distance measurement unit 26. When the mobile object 22 moves, the movement detection unit 124 detects the movement of the mobile object 22, and the distance measurement unit 26 measures the distance and direction to the structure 12. In this manner, as the mobile object 122 moves, distance information can be obtained that measures the distance from the mobile object 122 to the surfaces of the structure 12 and the markers 14 for each position of the mobile object 122, with the initial position of the mobile object 122 as a reference. The distance information obtained in this manner is transmitted to the information processing device 30 via the output unit 28, and point cloud data is generated, and a 3D map is generated.

[0040] The movement detection unit 124 (the movement detection unit 124 corresponds to the movement detection means of the present invention) is, for example, a known inertial measurement unit (IMU). This movement detection unit 124 includes a gyroscope and an accelerometer, and can detect a change in the position of the moving object 122 from a reference position. In other words, it can detect the current relative position of the moving object 122 with reference to the reference position of the moving object 122. By using an inertial measurement unit as the movement detection unit 124 in this way, it is possible to detect the current position of the moving object 122 even in a closed space such as indoors or underground, where the signal strength is low and an accurate position cannot be detected by a GPS system.

[0041] This three-dimensional map generation system 120 is similar to the three-dimensional map generation system 20, except that the mobile body 122 is provided with a movement detection unit 124 that detects the movement of the mobile body 122, and information regarding the movement detected by the movement detection means 124 is transmitted to the information processing device 30. Therefore, similar components are given similar symbols and will not be described here.

[0042] Next, a flow of generating a three-dimensional map of a closed space 10 will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of a three-dimensional map generating method according to another embodiment. For example, a case of generating a three-dimensional map of a place surrounded on all sides by structures 12 and where there is little change in the surface of the structures 12, such as an underground facility such as a sewer, will be described. When generating a three-dimensional map of a closed space 10, a plurality of markers 14 are placed in advance at a predetermined interval in the closed space 10 surrounded on all sides by the structures 12.

[0043] 6, the moving body 122 is placed at a starting point for starting generation of a three-dimensional map, and a start switch (not shown) on the moving body 122 is pressed, causing the movement detection unit 124 to start measuring information related to changes in the position of the moving body 122 (for example, acceleration and rotation angle), and the distance measurement unit 26 to start measuring the distance and direction from the moving body 122 to the surface positions of the structures 12 and markers 14 (step S210). At this time, the distance measurement unit 26 performs an omnidirectional scan, so that the distances and directions to the surfaces of the structures 12 and markers 14 present in all directions around the moving body 122 are measured, and information related to the respective directions and distances is obtained. At the same time, information related to changes in the position of the moving body 122 is obtained, so that relative position information from the starting position of the moving body 122 is obtained.

[0044] Next, the control unit 32 sets the start point as a first position and transmits information regarding the distance and direction from the moving object 22 to the surface positions of the structures 12 and markers 14, which was acquired by the distance measurement unit 26 at the start point, to the information processing device 30 as first distance information (step S220). Next, the control unit 32 moves the moving object 22 from the start point toward the end point, and transmits information regarding the distance and direction from the moving object 22 to the surface positions of the structures 12 and markers 14, which was acquired by the distance measurement unit 26 at a second position a certain distance from the start point, and relative position information of the moving object 122, as second distance information to the information processing device 30 (step S230). The moving object 122 repeats steps S220 and S230 and moves to the end point. At this time, the distance measurement unit 26 continues to measure the distance and direction to the surfaces of the structures 12 and markers 14 that exist in all directions from the center of the moving body 122, so as the moving body 22 moves, information regarding continuous surface information of the surfaces of the structures 12 and markers 14 from the start point to the end point, and relative position information based on the starting position of the moving body 122 are obtained.

[0045] Next, the control unit 32 generates point cloud data based on the relative position information, the first distance information, and the second distance information of the moving object 122, and generates a three-dimensional map based on this point cloud data (step S240). Note that step S240 is the same as step S140 except that point cloud data is generated based on the first distance information, and the relative position information and second distance information of the moving object 122, and therefore a description thereof will be omitted here.

[0046] When measuring an enclosed space 10 with little change in the surface of the structure 12, it may be impossible to correctly recognize the overlap of the point cloud data. In such cases, the distance from the first position to the second position may not be correctly recognized, and the distance from the first position to the second position on the generated 3D map may be shorter than the actual distance from the first position to the second position. However, by providing markers 14 at a predetermined interval, the markers 14 become feature points, reducing the possibility of incorrectly recognizing the overlap of the point cloud data and enabling the generation of a more accurate 3D map. In this case, the distance from the first position to the second position can be calculated more accurately by using relative position information obtained by the movement detection unit 124.

[0047] According to the method for generating a three-dimensional map using the three-dimensional map generation system 20 of the embodiment described above in detail, the markers 14 are placed at predetermined intervals on the surface of the structure 12 in the enclosed space 10, and therefore when the distance measurement unit 26 measures the distance and direction to the structure 12 or the marker 14, the marker 14 is included in the measurement range of the distance measurement unit 26. In this way, by combining the point cloud data of the first position and the point cloud data of the second position based on information about the position of the marker 14 included in the first distance information obtained at the first position and information about the position of the marker 14 included in the second distance information obtained at the second position, it is possible to generate a three-dimensional map that includes an area that cannot be measured from the first position.

[0048] Furthermore, according to the method for generating a three-dimensional map using the three-dimensional map generation system 120, the markers 14 are placed at predetermined intervals on the surface of the structure 12 in the enclosed space 10. Therefore, when the distance measurement unit 26 measures the distance and direction of the structure 12 or the marker 14, the marker 14 is included in the measurement range of the distance measurement unit 26. In this way, a three-dimensional map including an area that cannot be measured from the first position can be generated by combining the point cloud data for the first position and the point cloud data for the second position based on information about the position of the marker 14 included in the first distance information obtained at the first position and information about the position of the marker 14 included in the second distance information obtained at the second position. In this case, a more accurate three-dimensional map can be generated by adding information about the relative position of the second position calculated based on the information about the position obtained by the movement detection unit 124.

[0049] Furthermore, since the markers 14 are placed at a predetermined interval of 10 meters, which is the measurement range of the distance measurement unit 26, at least one marker 14 is always included in the measurement range of the distance measurement unit 26, allowing for more accurate generation of a three-dimensional map.

[0050] Furthermore, because the marker 14 is a hemisphere with a diameter of 100 millimeters, the marker 14 is easy to detect and does not interfere with measuring the distance to the surface of the structure 12, allowing for more accurate generation of a three-dimensional map.

[0051] It goes without saying that the present invention is not limited to the above-described embodiment, and can be embodied in various forms as long as they fall within the technical scope of the present invention.

[0052] For example, in the above-described embodiment, the mobile object 22 or the mobile object 122 and the information processing device 30 are electrically connected via a wireless communication line, but the information processing device 30 may be provided in the mobile object 22. In this case, the same effects as those of the above-described embodiment can be obtained.

[0053] In the above-described embodiment, the mobile unit 22 or the mobile unit 122 and the information processing device 30 are electrically connected via a wireless communication line, but this is not limited to this as long as the information processing device 30 can acquire various data acquired by the mobile unit 22 or the mobile unit 122. For example, the mobile unit 22 or the mobile unit 122 may have a removable storage means for temporarily storing various data, and the storage means removed from the mobile unit 22 or the mobile unit 122 may be attached to the information processing device 30, thereby allowing the information processing device 30 to acquire various data acquired by the mobile unit 22 or the mobile unit 122. In this case, the same effects as those of the above-described embodiment can be obtained.

[0054] In the above-described embodiment, the mobile unit 22 or the mobile unit 122 is moved inside the enclosed space 10 by being carried by an operator, but it may have a moving means such as wheels or caterpillar tracks and move according to commands from a predetermined program or the like, or may move according to commands from outside received via a wireless communication line or the like, or may move autonomously based on the movement of the mobile unit 122 detected by the movement detection unit 124 or the distance from the structure 12 to the mobile unit 22 or the mobile unit 122 measured by the distance measurement unit 26. In any case, the same effects as those of the above-described embodiment can be obtained.

[0055] In the above-described embodiment, a known inertial measurement unit is used as the movement detection unit 124, but the invention is not limited to an inertial measurement unit as long as it can detect the current position of the mobile object 122 relative to a reference position. For example, if the mobile object 122 has wheels, the current position of the mobile object 122 relative to the current position may be detected using a sensor that detects the number of rotations of the wheels and a gyro sensor, or the current position may be detected using only an accelerometer. In either case, the same effects as those of the above-described embodiment can be obtained.

[0056] In the above-described embodiment, a known gyroscope and acceleration sensor are used as the movement detection unit 124. However, in addition to the acceleration sensor, a known inclination sensor such as a tilt sensor may also be combined. In this way, even if the closed space is inclined, the current position of the moving object 122 relative to the initial position can be detected.

[0057] In the above-described embodiment, the information processing device 30 stores point cloud data and performs the process of generating a three-dimensional map, but multiple external devices may be used instead of the information processing device 30. That is, various information and programs may be distributed and stored in multiple external devices using blockchain technology or the like, or an external storage or the like may be used as the storage unit 34. In either case, the same effects as those of the above-described embodiment can be obtained.

[0058] In the above-described embodiment, the markers 14 are provided in advance on the surface of the structure 12, but the markers 14 may be provided only within the measurement range of the distance measurement unit 26. For example, if three markers 14 are provided in advance at 10-meter intervals, the moving body 22 or the moving body 122 may move forward 20 meters, then stop temporarily, and the rearmost marker 14 of the moving body 22 or the moving body 122 may be placed 10 meters apart from the frontmost marker 14, and the moving body 22 or the moving body 122 may be moved repeatedly. In this way, the same effect as in the above-described embodiment can be obtained without using four or more markers 14.

[0059] In the above case, when humans are used as markers 14, for example, three humans may wait at 10 meter intervals, move the moving body 22 or 122 forward 20 meters, then temporarily stop, and have the rearmost human of the moving body 22 or 122 wait at an interval of 10 meters from the forwardmost marker 14, and then move the moving body 22 or 122, repeating this operation. By doing so, even if there are not four or more humans, it is possible to obtain the same effect as in the above embodiment.

[0060] In the above-described embodiment, in steps S120 and S220, the moving person holds the moving body 22 or the moving body 122 and makes a round trip on the moving body 22 from the start point to the end point. However, the moving person may make a round trip multiple times. This allows more point cloud data to be obtained compared to making a single round trip, making it possible to generate a more accurate three-dimensional map. Also, after moving from the start point to the end point, it is not necessary to return to the start point. This reduces the amount of point cloud data obtained compared to making a round trip, reducing the amount of information processing required to generate the three-dimensional map and allowing the three-dimensional map to be generated more quickly. Which case to select can be appropriately selected depending on the purpose of generating the three-dimensional map.

[0061] In the above-described embodiment, step S140 or step S240 is executed after step S130 or step S230, but step S140 or step S240 may be executed after repeatedly executing steps S120 to S130 or steps S220 to S230. This allows a 3D map of a long distance to be generated at one time. [Industrial Applicability]

[0062] As shown in the above-described embodiment, the present invention can be utilized in the field of three-dimensional measurement, particularly in generating three-dimensional maps in enclosed spaces. [Explanation of symbols]

[0063] 10...Enclosed space, 12...Structure, 14...Marker, 20, 120...3D map generation system, 22, 122...Moving body, 26...Distance measurement unit, 28...Output unit, 30...Information processing device, 32...Control unit, 34...Memory unit, 36...Communication unit, 38...Bus, 124...Movement detection unit

Claims

1. A three-dimensional map generation method in which a moving body moving from a first position to a second position moves in a closed space surrounded on all sides by a structure having a plurality of markers set at a predetermined interval on its surface, and a three-dimensional map is generated using information about distances measured by distance measurement means provided on the moving body and measuring distances from the moving body to the surfaces of the structure and the markers, a first distance information acquisition step of acquiring, when the moving body is located at the first position, first distance information measuring a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers; a second distance information acquisition step of acquiring second distance information that measures a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers when the moving body is located at the second position; a combining step of combining first point cloud data indicating the positions of the structure and the marker derived from the first distance information based on information indicating the distance and direction to the surface of the marker, which is included in the first distance information, and second point cloud data indicating the positions of the structure and the marker derived from the second distance information based on information indicating the distance and direction to the surface of the marker, which is included in the second distance information; Including, How to generate a three-dimensional map.

2. A three-dimensional map generation method in which a moving body moving from a first position to a second position moves in a closed space surrounded on all sides by a structure having a plurality of markers set at a predetermined interval on its surface, and a three-dimensional map is generated using information about distance measured by a distance measurement means provided on the moving body and measuring the distance from the moving body to the surface of the structure and the markers, and information about movement of the moving body acquired by a movement detection means provided on the moving body and measuring information about the movement of the moving body, a first distance information acquisition step of acquiring, when the moving body is located at the first position, first distance information measuring a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers; a second distance information acquisition step of acquiring second distance information that measures a distance and a direction from the moving body to a surface of at least one of the structure and the plurality of markers when the moving body is located at the second position; a relative position calculation step of calculating a relative position of the second position with respect to the first position based on information about the movement of the moving object acquired by the movement detection means; a combining step of combining the first point cloud data and the second point cloud data based on the relative position of the second position calculated in the relative position calculating step, first point cloud data indicating the positions of the structure and the marker derived from the first distance information based on information indicating the distance and direction to the surface of the marker included in the first distance information, and second point cloud data indicating the positions of the structure and the marker derived from the second distance information based on information indicating the distance and direction to the surface of the marker included in the second distance information; Including, How to generate a three-dimensional map.

3. the predetermined arrangement interval is shorter than the measurement distance that can be measured by the distance measurement means; The method for generating a three-dimensional map according to claim 1 or 2.

4. The predetermined arrangement interval is 0.4 meters or more and 10 meters or less. The method for generating a three-dimensional map according to claim 3 .

5. The marker has a hemispherical shape with a diameter of 100 mm to 1000 mm. The method for generating a three-dimensional map according to claim 4.

6. 3. A program for executing the three-dimensional map generating method according to claim 1 or 2 on one or more computers.

7. A three-dimensional map generation system in which a mobile object moving from a first position to a second position moves in a closed space surrounded on all sides by a structure having a plurality of markers set at predetermined intervals on its surface, and a three-dimensional map is generated using information about distances measured by distance measurement means provided on the mobile object and measuring distances from the mobile object to the surfaces of the structure and the markers, an information acquisition means for acquiring first distance information that measures the distance and direction from the moving body to the surface of at least one of the structure and the plurality of markers when the moving body is located at the first position, and second distance information that measures the distance and direction from the moving body to the surface of at least one of the structure and the plurality of markers when the moving body is located at the second position; a combining means for combining first point cloud data indicating the positions of the structure and the marker derived from the first distance information based on information indicating the distance and direction to the surface of the marker, which is included in the first distance information, and second point cloud data indicating the positions of the structure and the marker derived from the second distance information based on information indicating the distance and direction to the surface of the marker, which is included in the second distance information; Equipped with A three-dimensional map generation system.

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