Survey method and survey system

Abstract

To provide a method and a system for efficiently surveying a laying position of a magnetic marker.SOLUTION: A survey system 1 for surveying a laying position of a magnetic marker 3 while moving includes: an estimation processing circuit for estimating a position and direction of a mobile body 10 by acquiring three-dimensional information of a runway environment with the use of a distance sensor mounted on the mobile body 10; and a survey processing circuit for identifying the laying position of the magnetic marker 3 with the position and direction of the mobile body 10 as a reference. The magnetic marker 3 is the marker to which a mark detectable by the distance sensor is attached at least in surveying. In the surveying system 1, when the magnetic marker 3 is detected by the distance sensor, the position and direction of the mobile body 10 are estimated by acquiring the three-dimensional information of the runway environment to which the magnetic marker 3 belongs. Then, the laying position of the magnetic marker 3 is identified with the position and direction of the mobile body as a reference.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and system for surveying the positions of magnetic markers that are installed so as to be detectable while a vehicle is traveling. [Background technology]

[0002] Conventionally, magnetic markers that are laid on roads so as to be detectable by vehicles have been known (see, for example, Patent Document 1). Magnetic markers can be detected, for example, by using a magnetic sensor mounted on a vehicle. For example, by using magnetic markers laid along the lanes that form the road on which an automobile travels, various driving assistance systems such as automatic steering control and lane departure warning can be realized, as well as automatic driving.

[0003] For example, by installing magnetic markers on the path of a transport vehicle moving within a factory, a system can be constructed that automatically drives the transport vehicle along the path. Such a system can automate the transportation of materials within the factory, reducing the number of workers required and suppressing production costs (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-17383 A [Patent Document 2] JP 2023-50720 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, the conventional systems using magnetic markers have the following problems: In order to control automobiles traveling on roads and transport vehicles moving within factories with high precision, it is necessary to grasp the installation positions of the magnetic markers with high precision, but installing the magnetic markers with high precision may lead to an increase in construction costs.

[0006] The present invention has been made in consideration of the above-mentioned problems in the conventional art, and aims to provide a method and system for efficiently surveying the installation positions of magnetic markers. [Means for solving the problem]

[0007] One aspect of the present invention is a method for measuring, while a moving object is moving, positions of magnetic markers that are laid on a road so as to be magnetically detectable by a magnetic sensor provided in the vehicle, the method comprising the steps of: An estimation process of acquiring three-dimensional information of a road environment using a distance sensor mounted on a moving object and estimating a position and orientation of the moving object; A surveying process for identifying the installation positions of the magnetic markers based on the position and orientation of the moving body, The magnetic marker is a magnetic marker configured to be detectable by the distance sensor, or a mark detectable by the distance sensor is attached to the magnetic marker at least during surveying, This is a surveying method in which, when the magnetic marker is detected by the distance sensor, three-dimensional information of the road environment to which the magnetic marker belongs is obtained to estimate the position and orientation of the moving body, and the installation position of the magnetic marker is identified based on the position and orientation of the moving body.

[0008] One aspect of the present invention is a system for measuring, while a moving object is moving, the positions of magnetic markers that are laid on a road so as to be magnetically detectable by a magnetic sensor equipped in the vehicle, the system comprising: an estimation processing circuit that acquires three-dimensional information of a road environment using a distance sensor mounted on the moving object and estimates a position and orientation of the moving object; A survey processing circuit for identifying the installation position of the magnetic marker based on the position and orientation of the moving body, The magnetic marker is a magnetic marker configured to be detectable by the distance sensor, or a mark detectable by the distance sensor is attached to the magnetic marker at least during surveying, This surveying system is configured so that, when the magnetic marker is detected by the distance sensor, the estimation processing circuit acquires three-dimensional information of the road environment to which the magnetic marker belongs, estimates the position and orientation of the moving body, and the estimation processing circuit identifies the installation position of the magnetic marker based on the position and orientation of the moving body. Effect of the Invention

[0009] The surveying system and the magnetic marker in the surveying system of the present invention are magnetic markers configured to be detectable by a distance sensor, or are magnetic markers to which a mark detectable by a distance sensor is attached at least during surveying. In the present invention, when a magnetic marker is detected by a distance sensor, three-dimensional information of the road environment to which the magnetic marker belongs is obtained to estimate the position and orientation of a moving object, and the installation position of the magnetic marker is specified based on the position and orientation of the moving object.

[0010] The surveying system and surveying method of the present invention are a system or method for surveying and identifying the installation positions of magnetic markers while a moving body is moving. In the present invention, the magnetic markers detected by a distance sensor can be used to estimate the position and orientation of the moving body. According to the present invention, the installation positions of the magnetic markers can be efficiently surveyed and identified while estimating the position and orientation of the moving body using the magnetic markers that are the surveying target. [Brief description of the drawings]

[0011] [Figure 1] FIG. 2 is an explanatory diagram of a track on which magnetic markers are installed in the first embodiment. [Diagram 2] FIG. 2 is a perspective view of a magnetic marker in the first embodiment. [Diagram 3] FIG. 2 is a perspective view of a marker pole erected directly above a magnetic marker in the first embodiment. [Figure 4] FIG. 2 is a perspective view of a measurement vehicle in the first embodiment. [Diagram 5] FIG. 2 is an explanatory diagram of two two-dimensional range sensors provided on a measurement vehicle in the first embodiment. [Figure 6]FIG. 4 is an explanatory diagram showing how a measurement vehicle detects a marker pole in the first embodiment. [Figure 7] FIG. 2 is a block diagram showing the electrical configuration of a measurement vehicle in the first embodiment. [Figure 8] FIG. 4 is a flowchart showing the flow of an estimation process in the first embodiment. [Figure 9] FIG. 4 is a flow diagram showing the flow of a surveying process in the first embodiment. [Figure 10] 4 is an explanatory diagram showing a distance Kp and a relative direction θp from a measurement vehicle to a marker pole in the first embodiment. FIG. [Figure 11] FIG. 2 is an explanatory diagram of a method for measuring the installation position (absolute position) of a magnetic marker in the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] For example, in a roadway surrounded by walls such as a tunnel, the distance sensor can detect the tunnel walls, but there may be few objects that the distance sensor can detect in the direction of the road (travel direction). In such a case, it is easy to identify the position of a moving object in the width direction of the road, but the accuracy of identifying the position in the direction of the road may be impaired. In the present invention, magnetic markers laid on the road can be detected by the distance sensor, and can be used to estimate the position and orientation of a moving object.

[0013] The embodiment of the present invention will be specifically described using the following examples. Example 1 This embodiment relates to a surveying system 1 and a surveying method in which a measurement vehicle 10 (FIG. 1) moves along a road while identifying installation positions of magnetic markers 3. The contents of this embodiment will be described with reference to FIGS.

[0014] In this example, a transport vehicle track (FIG. 1) provided within a facility such as a factory is illustrated, with magnetic markers 3 laid along the route direction. The surveying system 1 is a system in which a measurement vehicle 10, which is an example of a moving body, surveys and identifies the installation positions of the magnetic markers 3 while moving along the track. The track in this example is a circular track for transport vehicles (not shown) to travel around the facility.

[0015] The magnetic marker 3 (FIG. 2) is a small sheet-like magnet with a diameter of 50 mm and a thickness of 2 mm. The magnetic marker 3 is laid by gluing it to the road surface. When surveying the placement position of the magnetic marker 3, a rod-shaped marker pole 3P, which is an example of a marker member, is erected directly above the magnetic marker 3. The marker pole 3P (FIG. 3) is rod-shaped with a diameter of 25 mm and a length of 1 m 20 cm, and is provided with a base 30 with a diameter of 100 mm and a thickness of 25 mm. The base 30 is made of transparent acrylic resin so that the magnetic marker 3 directly below can be seen. The marker pole 3P is configured to reflect light well. In addition, a recess (not shown) with a diameter and depth capable of accommodating the magnetic marker 3 is provided on the back side of the base 30. The marker pole 3P is erected in a state in which the magnetic marker 3 is accommodated in this recess.

[0016] The measurement vehicle 10 (FIG. 4) is a four-wheel vehicle equipped with a pair of steered front wheels 101 on the left and right, and a rear wheel 102 that is a drive wheel with a fixed steering wheel. The measurement vehicle 10 is about 2 m long, 1 m wide, and 1 m high. The measurement vehicle 10 can simultaneously perform self-localization and map creation (mapping) while moving along a road. The surveying system 1 of this example uses the self-localization function of the measurement vehicle 10 to survey and identify the installation position of the magnetic marker 3 while moving. As described above, when surveying the installation position of the magnetic marker 3, a marker pole 3P is erected directly above the magnetic marker 3. The measurement vehicle 10 automatically travels so as to bypass the magnetic marker 3, thereby avoiding interference with the marker pole 3P.

[0017] The measurement vehicle 10 includes two two-dimensional range sensors (2D range sensors) 111 and 112, as shown in FIG. 4 and FIG. 5. The two-dimensional range sensors 111 and 112 are one-axis scanning type range sensors. Both of the two-dimensional range sensors 111 and 112 are LiDARs that measure the distance to an object present within a scanning plane while one-dimensionally scanning a laser beam (an example of an electromagnetic wave). The two-dimensional range sensors 111 and 112 measure the presence of an object and the distance to the object by using the light reflected from the object when scanning with the laser beam. The two-dimensional range sensors 111 and 112 measure the reflection time until the reflected light returns from the object, thereby identifying the distance corresponding to the reflection time.

[0018] The two-dimensional range sensors 111 and 112 acquire point cloud data, which is distance information (three-dimensional information) within a scanning plane. The two-dimensional range sensors 111 and 112 have different installation locations and scanning planes (hereinafter referred to as measurement planes) due to differences in installation purposes.

[0019] A two-dimensional range sensor 111 (FIG. 5), which is an example of a distance sensor, is attached to the upper surface of the measurement vehicle 10. The measurement surface of this two-dimensional range sensor 111 is a horizontal plane Sh parallel to the central axis CL of the vehicle body. The two-dimensional range sensor 111 measures the distance to an object present in the horizontal plane Sh, and outputs point cloud data of the horizontal plane Sh. The point cloud data of the horizontal plane Sh is used in an estimation process for estimating the position (host vehicle position) and orientation of the measurement vehicle 10. The two-dimensional range sensor 111 is attached to the upper surface of the measurement vehicle 10, which is 1 m high. With this two-dimensional range sensor 111, it is possible to reliably detect a marker pole 3P with a length of 1.2 m erected on a magnetic marker 3, as shown in FIG. 6.

[0020] The two-dimensional range sensor 112 (FIGS. 4 and 5) is attached to the front of the measurement vehicle 10. The measurement surface of the two-dimensional range sensor 112 is a vertical plane Sv perpendicular to the central axis CL of the vehicle body. The two-dimensional range sensor 112 measures the distance to an object existing within the vertical plane Sv, and outputs point cloud data of the horizontal plane Sv. The point cloud data of the vertical plane Sv is used to create a three-dimensional map.

[0021] 7, the measurement vehicle 10 includes two-dimensional range sensors 111, 112, a main board 10B, a memory unit 100, a steering unit 22 for the steering wheels (front wheels 101), a drive motor 24 for the drive wheels (rear wheels 102), etc. The main board 10B includes a control circuit 20 for automatic driving, an estimation processing circuit 12 for position estimation, a survey processing circuit 14 for surveying the installation positions of the magnetic markers 3, a mapping circuit 16 for map creation, etc.

[0022] The memory unit 100 stores data acquired in response to movement as needed, and also stores a two-dimensional map of the road in advance. The data acquired in response to movement includes three-dimensional map data created by the mapping circuit 16, data on the installation positions of the magnetic markers 3 identified by surveying processing, and the like. Furthermore, the memory unit 100 stores structure data that represents the three-dimensional structure of a specific point on the road. The structure data has a defined reference orientation, and is linked to position data that represents the absolute position on the two-dimensional map.

[0023] In this example, for example, a plurality of locations exhibiting a characteristic three-dimensional structure are set as specific locations. As described above, the structure data is linked to position data on a two-dimensional map, and the absolute positions of the corresponding specific locations are known. The structure data, in which the absolute positions are known and the reference orientation is determined, can be used for position estimation to identify the absolute position and absolute orientation of the measurement vehicle 10.

[0024] The estimation processing circuit 12 (FIG. 7) is a circuit that executes estimation processing to estimate the vehicle position and orientation using point cloud data acquired by the two-dimensional range sensor 111, whose measurement surface (scanning plane) is the horizontal plane Sh. The specific contents of the estimation processing will be described later with reference to FIG.

[0025] The survey processing circuit 14 (FIG. 7) is a circuit that surveys and identifies the installation position of the magnetic marker 3 by using the point cloud data acquired by the two-dimensional range sensor 111. The survey processing circuit 14 acquires data (distance information, three-dimensional information) related to the marker pole 3P erected directly above the magnetic marker 3 from the point cloud data, and surveys the installation position of the magnetic marker 3. The contents of this survey processing will be described in detail later with reference to FIG. 9.

[0026] The mapping circuit 16 (FIG. 7) is a circuit that creates a three-dimensional map from point cloud data acquired by the two-dimensional range sensor 112, whose measurement plane (scanning plane) is the vertical plane Sv. The mapping circuit 16 creates a three-dimensional map by allocating distance information (three-dimensional information) of each point represented by the point cloud data to a corresponding point on the map.

[0027] The measurement vehicle 10 configured as above automatically travels along a road using a two-dimensional map read from the storage unit 100. During automatic travel, the measurement vehicle 10 repeatedly executes the above estimation process (FIG. 8). In the estimation process, as described above, the position and orientation of the measurement vehicle 10 are estimated using point cloud data acquired by the two-dimensional range sensor 111 whose measurement surface is the horizontal plane Sh.

[0028] In the configuration of this example, the measurement vehicle 10 starts moving from a start position whose absolute position and absolute orientation are known. Therefore, the initial position and initial orientation when starting automatic driving can be grasped on the vehicle side. Furthermore, in the configuration of this example, as described above, structure data of multiple specific locations on the road is stored in the storage unit 100. The structure data is three-dimensional structure data in which the absolute position is specified and the reference orientation is determined. The structure data is used to identify the absolute position and absolute orientation of the measurement vehicle 10 by collating point cloud data acquired by the two-dimensional range sensor 111. The absolute position and absolute orientation of the measurement vehicle 10 can be identified at the start point and can also be identified when the point cloud data acquired by the two-dimensional range sensor 111 can be collated with the structure data.

[0029] The measurement vehicle 10 creates a 3D map while traveling automatically. The measurement vehicle 10 creates a 3D map by allocating 3D information based on point cloud data of the 2D range sensor 112, whose measurement surface is the vertical surface Sv, to each position on the map as described above. When creating a map in this manner, the position and orientation of the measurement vehicle 10 estimated by the above estimation process are used.

[0030] Next, the details of the estimation process (FIG. 8) for estimating the position and orientation of the measurement vehicle 10 and the survey process (FIG. 9) for identifying the installation positions of the magnetic markers 3 will be described. (Estimation process) The flow of the estimation process will be described with reference to the flow diagram of Fig. 8. The estimation process is executed in response to the start of movement of the measurement vehicle 10. When the measurement vehicle 10 starts moving (S101: YES), a predetermined initial position and initial orientation of the measurement vehicle 10 are identified as the vehicle position and orientation (S102).

[0031] After the measurement vehicle 10 starts moving, the estimation processing circuit 12 acquires point cloud data repeatedly acquired by the two-dimensional range sensor 111 at any time (S103). When the estimation processing circuit 12 acquires point cloud data, it stores the immediately preceding point cloud data without erasing it. The estimation processing circuit 12 stores time-series point cloud data over a predetermined time period in the past.

[0032] When the inference processing circuit 12 acquires the point cloud data, it sequentially reads out the structure data of the specific location stored in the storage unit 100 as described above (S104). Then, the inference processing circuit 12 attempts to match the read out structure data with the point cloud data, and determines whether the match is successful (S105). If the match is not successful (S105: NO), the inference processing circuit 12 repeatedly executes the reading out of the structure data (S104) and the determination of whether the match is successful (S105) until there is no unread structure data (S116: NO).

[0033] When it is determined that the point cloud data acquired by the two-dimensional range sensor 111 can be matched with the structure data of any specific location (S105: YES), the estimation processing circuit 12 reads out the position data associated with that structure data (S106). This position data is data that represents the absolute position of the specific location related to the structure data. As described above, the structure data is data in which a reference orientation is defined and an absolute position is specified. Therefore, when the point cloud data can be matched with the structure data, it becomes possible to estimate the absolute position and orientation of the measurement vehicle 10 based on the absolute position and reference orientation of the structure data (S107).

[0034] On the other hand, if the point cloud data acquired by the 2D range sensor 111 cannot be matched with any of the structure data (S105: NO → S116: YES), the estimation processing circuit 12 refers to the point cloud data acquired at the most recent past point when the position and orientation of the measurement vehicle 10 could be estimated, and identifies the amount of change over time in the position and orientation from the past point cloud data to the latest point cloud data (S117).

[0035] The estimation processing circuit 12 estimates the latest position and orientation of the measurement vehicle 10 based on the position and orientation of the measurement vehicle 10 at the most recent past time (S118). Specifically, based on the position and orientation of the measurement vehicle 10 at the most recent past time, the most recent position (vehicle position) and orientation of the measurement vehicle 10 are estimated by shifting the position or orientation by the amount of change in the position and orientation over time.

[0036] When estimating the position and orientation of the measurement vehicle 10 from changes over time in the point cloud data, the marker poles 3P are useful for improving the estimation accuracy. In particular, in an aisle between walls on both sides and with no structures ahead of the road, it may be difficult to ensure the estimation accuracy of the longitudinal position of the measurement vehicle 10. In such cases, the marker poles 3P erected on the road are effective. By using point cloud data that includes distance information (three-dimensional information) from the marker poles 3P, it is possible to improve the estimation accuracy of the longitudinal position of the measurement vehicle 10.

[0037] (Survey processing) The survey processing (FIG. 9) is processing that the survey processing circuit 14 executes in response to the detection of the marker pole 3P by the two-dimensional range sensor 111. If the marker pole 3P has not been detected (S201: NO), the survey processing circuit 14 waits as is. If the marker pole 3P is detected (S201: YES), the survey processing circuit 14 executes processing following step S202 to identify the installation position of the magnetic marker 3.

[0038] When the marker pole 3P is detected (S201: YES), the survey processing circuit 14 extracts distance information of the marker pole 3P from the point cloud data by the two-dimensional range sensor 111. Then, based on the distance information of the marker pole 3P, the survey processing circuit 14 specifies the distance Kp to the marker pole 3P and the orientation θp of the marker pole 3P, as shown in Fig. 10 (S202). The distance Kp to the marker pole 3P is the distance based on the measurement vehicle 10. The orientation θp of the marker pole 3P is the relative orientation based on the central axis CL of the measurement vehicle 10.

[0039] The survey processing circuit 14 reads the position and orientation (absolute position, absolute orientation) of the measurement vehicle 10 estimated by the estimation process (FIG. 8) (S203). Then, as shown in FIG. 11, the absolute position (Xp, Yp) of the magnetic marker 3 is identified based on the position (Xv, Yv) and central axis CL of the measurement vehicle 10 (S204). The orientation θv of the central axis CL of the measurement vehicle 10 estimated by the estimation process is an absolute orientation defined on a two-dimensional coordinate system that is a global coordinate system. The absolute orientation of the marker pole 3P based on the measurement vehicle 10 can be identified by adding the relative orientation θp of the marker pole 3P to the orientation θv of the central axis CL of the measurement vehicle 10.

[0040] Once the absolute orientation of the marker pole 3P is known, the distance Kp to the marker pole 3P can be converted into a relative position (ΔX, ΔY) on a two-dimensional coordinate system, as shown in Fig. 11. By adding this relative position (ΔX, ΔY) on the two-dimensional coordinate system to the position (Xv, Yv) of the measurement vehicle 10, the position (Xp, Yp) of the marker pole 3P on the two-dimensional coordinate system can be identified. Naturally, this position (Xp, Yp) of the marker pole 3P on the two-dimensional coordinate system represents the installation position of the magnetic marker 3. The installation position of the magnetic marker 3 identified by such surveying is stored in the memory unit 100 as needed.

[0041] As described above, the surveying system 1 of this example is a system that estimates the position and orientation of the measurement vehicle 10 using the optically detected magnetic marker 3 (marker pole 3P), and also measures and identifies the installation position of the magnetic marker 3 based on the estimated position and orientation of the measurement vehicle 10. The surveying system 1 of this example can efficiently measure the installation position of the magnetic marker 3 while moving along the course. In particular, the surveying system 1 of this example can improve the accuracy of estimating the position of the measurement vehicle 10 by detecting the marker pole 3P (an example of a component) that serves as a landmark for the magnetic marker 3. If the position and orientation of the measurement vehicle 10 can be estimated with high accuracy, the accuracy of measuring the installation position of the magnetic marker 3 can be improved.

[0042] In this example, a two-dimensional range sensor 111 whose measurement surface is a horizontal plane Sh is used to detect the marker pole 3P and identify the installation position of the corresponding magnetic marker 3. Instead of the two-dimensional positioning sensor 111, a radio wave radar such as a millimeter wave radar that measures the distance to an object using radio waves, which are an example of electromagnetic waves, may be used to detect the marker pole 3P and identify the installation position of the corresponding magnetic marker 3.

[0043] Also, instead of using the two-dimensional range sensor 111, it is also possible to process an image acquired by an imaging camera to detect the marker pole 3P and identify the installation position of the corresponding magnetic marker 3. A stereo camera combining at least two imaging cameras can measure the distance to the marker pole 3P. For example, if it is possible to set a constraint condition such as a flat road surface, it is also possible to estimate the distance to the marker pole 3P based on an image captured by one imaging camera. This is because, if the optical axis of the imaging camera is specified, the vertical position of the marker pole 3P on the image is determined according to the distance.

[0044] In this example, a sheet-shaped magnetic marker is placed on the road surface, but a columnar magnetic marker may be used instead. The columnar magnetic marker may be housed in a hole drilled in the road surface or placed on the road surface.

[0045] Instead of the two-dimensional range sensor 111 that scans the laser light one-dimensionally, a three-dimensional range sensor that scans the laser light two-dimensionally may be used. In this case, it is not essential to erect the marker pole 3P directly above the magnetic marker 3. It is preferable to form the magnetic marker from a material that can be detected by LiDAR, or to paint the surface or outer peripheral side of the magnetic marker with paint that can be detected by LiDAR. In this case, the magnetic marker itself can be detected by the three-dimensional range sensor. Examples of materials that can be detected by LiDAR include materials mixed with light-reflecting beads or aluminum powder.

[0046] It is also possible to lay the magnetic marker so that it can be imaged, or to provide the magnetic marker with a marking that can be imaged. In this case, the magnetic marker can be detected by an imaging camera. When a columnar magnetic marker is housed in a hole, it is also possible to provide a lid for the hole. It is preferable to configure the lid so that it can be detected by a 3D range sensor or an imaging camera. When the magnetic marker is buried, the marking material for the magnetic marker can be paint on the road surface that serves as a marking to indicate the magnetic marker, or the lid of the hole for housing the magnetic marker, etc.

[0047] In the configuration of this example, the structure data of a specific location on the road is stored in advance in a state where it is linked to position data representing an absolute position. For example, if the initial position and initial direction when starting autonomous driving can be specified, the structure data of the specific location is not essential. However, if a specific location is not set on the road, there is a risk that errors will accumulate as the distance of autonomous driving increases. On the other hand, if there is a specific location where the absolute position and absolute direction can be specified, the accumulated errors can be reset and the position estimation accuracy can be improved. In this example, the reference direction of the structure data representing the three-dimensional structure of the specific location on the road is determined in advance. The reference direction of the structure data may be arbitrary. If the reference direction of the structure data is arbitrary, it is advisable to link the reference direction to the structure data together with the absolute position.

[0048] In this example, a measurement vehicle 10 that moves on a road surface is exemplified as a moving body, but it may also be a drone that moves in the air or underwater. The measurement vehicle 10 may be provided with a communication function for exchanging information with an external server device. In this case, among the components shown in Fig. 7, components other than the two-dimensional range sensors 111 and 112, the steering unit 22, and the drive motor 24 can be provided in the server device (not shown).

[0049] Although specific examples of the present invention have been described in detail as examples, these specific examples merely disclose examples of the technology encompassed by the claims. Needless to say, the claims should not be interpreted as being limited by the configurations, numerical values, etc. of the specific examples. The claims encompass technologies that are obtained by variously modifying, changing, or appropriately combining the specific examples by utilizing publicly known technologies and the knowledge of those skilled in the art. [Explanation of symbols]

[0050] 1. Surveying System 10 Measurement vehicle (mobile) 100 Storage section 111 2D Range Sensor (Distance Sensor) 112 2D Range Sensor 12 Estimation processing circuit 14 Survey processing circuit 16 Mapping Circuit 22 Steering unit 24 Drive motor 3 Magnetic marker 3P marker pole (marker, component) CL center axis Sh horizontal plane (measurement plane, scanning plane) Sv Vertical plane (measurement plane, scanning plane)

Claims

1. A method for measuring, while a moving object is moving, the positions of magnetic markers that are laid on a road so as to be magnetically detectable by a magnetic sensor provided in the vehicle, the method comprising the steps of: An estimation process of acquiring three-dimensional information of a road environment using a distance sensor mounted on a moving object and estimating a position and a direction of the moving object; A surveying process for identifying the installation positions of the magnetic markers based on the position and orientation of the moving body, The magnetic marker is a magnetic marker configured to be detectable by the distance sensor, or a mark detectable by the distance sensor is attached to the magnetic marker at least during surveying, A surveying method in which, when the magnetic marker is detected by the distance sensor, three-dimensional information of the road environment to which the magnetic marker belongs is obtained to estimate the position and orientation of the moving body, and the installation position of the magnetic marker is identified based on the position and orientation of the moving body.

2. 2. The distance sensor according to claim 1, wherein the distance sensor measures a distance to an object that corresponds to a reflection time when an electromagnetic wave is irradiated to the object, and A surveying method in which the magnetic marker is a magnetic marker placed on the surface of the track so as to reflect the electromagnetic waves emitted from the distance sensor, or a magnetic marker in which a component provided on the surface of the track so as to reflect the electromagnetic waves emitted from the distance sensor is attached as the landmark.

3. 3. The surveying method according to claim 2, wherein the distance sensor is a two-dimensional range sensor having a measurement surface along a horizontal plane, and the mark is a rod-shaped pole erected at a position where a magnetic marker is to be laid during surveying.

4. 2. The method according to claim 1, wherein the distance sensor is one or more imaging cameras capable of measuring a distance to an object in a photographing area, A surveying method in which the magnetic marker is a magnetic marker placed on the surface of the track so that it can be photographed by the one or more multiple imaging cameras, or a magnetic marker in which a component provided on the surface of the track is attached as the landmark so that it can be photographed by the one or more multiple imaging cameras.

5. A system for measuring the positions of magnetic markers laid on a road so as to be magnetically detectable by a magnetic sensor mounted on the vehicle while the vehicle is moving, comprising: an estimation processing circuit that acquires three-dimensional information of a road environment using a distance sensor mounted on the moving object and estimates a position and a direction of the moving object; A survey processing circuit for identifying the installation position of the magnetic marker based on the position and orientation of the moving body, The magnetic marker is a magnetic marker configured to be detectable by the distance sensor, or a mark detectable by the distance sensor is attached to the magnetic marker at least during surveying, A surveying system configured such that when the magnetic marker is detected by the distance sensor, the position and orientation of the moving body are estimated by the estimation processing circuit which acquires three-dimensional information of the road environment to which the magnetic marker belongs, and the installation position of the magnetic marker is identified by the estimation processing circuit based on the position and orientation of the moving body.

6. According to claim 5, the distance sensor is a sensor that measures a distance to an object corresponding to a reflection time when an electromagnetic wave is irradiated to the object, and A surveying system in which the magnetic marker is a magnetic marker placed on the surface of a track so as to reflect electromagnetic waves emitted from the distance sensor, or a magnetic marker in which a component provided on the surface of the track so as to reflect electromagnetic waves emitted from the distance sensor is attached as the landmark.

7. 7. A surveying system according to claim 6, wherein the distance sensor is a two-dimensional range sensor having a measurement surface along a horizontal plane, and the mark is a rod-shaped pole erected at a position where a magnetic marker is to be laid during surveying.

8. According to claim 5, the distance sensor is one or more imaging cameras capable of measuring a distance to an object in a photographing area, A surveying system in which the magnetic marker is a magnetic marker placed on the surface of the track so that it can be photographed by the one or more multiple imaging cameras, or a magnetic marker in which a component provided on the surface of the track is attached as the landmark so that it can be photographed by the one or more multiple imaging cameras.

Images