Point cloud data generation device, point cloud data generation system, and point cloud data generation program

Abstract

To evaluate the quality of a laser point cloud for detecting a terrestrial object.SOLUTION: Provided is a point cloud data generator 1 that generates the three-dimensional coordinate of a terrestrial object as point cloud data on the basis of reflected light of a laser beam. The point cloud data generator 1 comprises: data acquisition means 101 for acquiring the position coordinate of a laser scanner 21 detected by a GNSS 22 / IMU 23 and the attitude of the laser scanner 21; calculation means 103 for calculating an azimuth angle in which a carriage 3 moves as a first azimuth angle on the basis of the attitude acquired by the data acquisition means 101, and calculating an azimuth angle in which the carriage 3 moves as a second azimuth angle on the basis of the plurality of position coordinates acquired by the data acquisition means 101; and determination means 104 that determines that a distortion occurs to the point cloud data in a direction orthogonal to the movement direction of the carriage 3, when the difference between an azimuth angle D1 calculated by the calculation means 103 and a second azimuth angle D2 calculated by the calculation means 103 is greater than or equal to a prescribed azimuth angle threshold ThD.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a point cloud data generation device, a point cloud data generation system, and a point cloud data generation program for generating point cloud data for detecting ground objects.

Background Art

[0002] In recent years, mobile objects such as automobiles and railways have been equipped with laser scanners that emit laser pulses, enabling the acquisition of three-dimensional coordinates (laser point clouds) of ground objects in front of, behind, or on the side of the mobile object.

[0003] Laser point clouds obtained by mobile measurement are generated by integrating distance data acquired by a laser scanner and travel trajectory data calculated for the position and orientation of the laser scanner that changes moment by moment. Although there are no major error factors in the laser scanner data itself, the travel trajectory data is calculated by integrating GNSS (Global Navigation Satellite System) positioning data and inertial measurement data of an IMU (inertial measurement unit). At this time, large errors may occur in the position and orientation in an overhead visibility poor section (non-GNSS section) where GNSS positioning is difficult, such as in a tunnel.

[0004] Patent Document 1 discloses a method of calibrating laser measurement data based on reference points and verification points and determining quality (accuracy) based on the effective distance of laser measurement.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] ​However, the technology described in Patent Document 1 determines quality (accuracy) based on the effective distance of laser measurement. This method assumes positioning in GNSS sections where there is good overhead visibility and GNSS positioning is possible, making it difficult to use in non-GNSS sections where GNSS positioning is difficult, such as tunnels.

[0007] The present invention has been made in view of the above-mentioned problems, and aims to provide a point cloud data generation device, a point cloud data generation system, and a point cloud data generation program for evaluating the quality of laser point clouds used to detect geographic features. [Means for solving the problem]

[0008] To solve the above objective, the first feature of the point cloud data generation device according to the present invention is: A point cloud data generation device that generates the three-dimensional coordinates of geographic features as point cloud data based on the reflected light of laser beams emitted from a laser scanner mounted on a mobile body onto geographic features around the mobile body, An acquisition means for acquiring the position coordinates of the laser scanner detected by the detection means and the orientation of the laser scanner, A calculation means that calculates the azimuth angle at which the moving body moves based on the attitude acquired by the acquisition means as the first azimuth angle (before heading correction), and calculates the azimuth angle at which the moving body moves based on a plurality of position coordinates acquired by the acquisition means as the second azimuth angle (COG), A determination means that determines that distortion occurs in the point cloud data in a direction perpendicular to the direction of movement of the moving object when the difference between the first azimuth angle calculated by the calculation means and the second azimuth angle calculated by the calculation means is greater than or equal to a predetermined azimuth angle threshold, It is equipped with this.

[0009] The second feature of the point cloud data generation device according to the present invention is, If the determination means determines that no distortion occurs, the generation means generates the point cloud data based on the first azimuth angle; if the determination means determines that distortion occurs, the generation means corrects the first azimuth angle using the second azimuth angle and generates the point cloud data based on the corrected first azimuth angle. Furthermore, they have made additional preparations.

[0010] The third feature of the point cloud data generation device according to the present invention is: The calculation means calculates a vector connecting a plurality of position coordinates obtained by the acquisition means, and calculates the direction of the calculated vector as the second azimuth angle. It is the matter.

[0011] The first feature of the point cloud data generation system according to the present invention is, A point cloud data generation system comprising a laser scanner mounted on a mobile body and receiving reflected light from laser beams irradiated onto geographical features around the mobile body, and generating the three-dimensional coordinates of the geographical features as point cloud data based on the received reflected light, Positioning means for detecting the position coordinates of the laser scanner, A posture detection means for detecting the posture of the laser scanner, A calculation means that calculates the azimuth angle at which the moving body moves based on the attitude detected by the attitude detection means as the first azimuth angle (before heading correction), and calculates the azimuth angle at which the moving body moves based on a plurality of position coordinates acquired by the positioning means as the second azimuth angle (COG), A determination means that determines that distortion occurs in the point cloud data in a direction perpendicular to the direction of movement of the moving object when the difference between the first azimuth angle calculated by the calculation means and the second azimuth angle calculated by the calculation means is greater than or equal to a predetermined azimuth angle threshold, It is equipped with this.

[0012] The first feature of the point cloud data generation program according to the present invention is, A point cloud data generation program executed by a point cloud data generation device that generates the three-dimensional coordinates of geographic features as point cloud data based on the reflected light of laser light emitted from a laser scanner mounted on a mobile body onto geographic features around the mobile body, An acquisition step of acquiring the position coordinates of the laser scanner detected by the detection means and the orientation of the laser scanner, A calculation step which calculates the azimuth angle at which the moving body moves based on the attitude acquired in the acquisition step as the first azimuth angle (before heading correction), and calculates the azimuth angle at which the moving body moves based on the multiple position coordinates acquired in the acquisition step as the second azimuth angle (COG), A determination step in which, if the difference between the first azimuth angle calculated by the calculation step and the second azimuth angle calculated by the calculation step is greater than or equal to a predetermined azimuth angle threshold, it is determined that distortion occurs in the point cloud data in a direction perpendicular to the direction of movement of the moving object, The objective is to have the point cloud data generation device perform this operation. [Effects of the Invention]

[0013] According to the point cloud data generation device, point cloud data generation system, and point cloud data generation program of the present invention, the quality of laser point clouds for detecting geographic features can be evaluated. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing the general configuration of a point cloud data generation system, which is one embodiment of the present invention. [Figure 2] This is a schematic diagram illustrating the generation of point cloud data by a point cloud data acquisition device 2 included in a point cloud data generation system 100, which is one embodiment of the present invention. [Figure 3] This is an explanatory diagram that schematically illustrates the occurrence of errors. [Figure 4]This is an explanatory diagram for explaining the processing by the speed determination means 104A included in the point cloud data generation system 100 which is an embodiment of the present invention. Fig. 4(a) is a diagram comparing the first speed V1 and the second speed V2, and Fig. 4(b) is a diagram showing the difference between the first speed V1 and the second speed V2. [Figure 5] This shows the difference DD between the first azimuth angle D1 and the second azimuth angle D2 calculated by the calculation means 103 included in the point cloud data generation system 100 which is an embodiment of the present invention. [Figure 6] This is a diagram comparing the point cloud data before correction and the point cloud data after correction by the generation means 105 in the point cloud data generation system 100 which is an embodiment of the present invention when distortion occurs in the moving direction. [Figure 7] This is a diagram comparing the point cloud data before correction and the point cloud data after correction in the point cloud data generation system 100 which is an embodiment of the present invention when distortion occurs in the direction orthogonal to the moving direction. [Figure 8] This is a flowchart showing the processing content in the point cloud data generation system 100 which is an embodiment of the present invention.

Mode for Carrying Out the Invention

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or equivalent parts and components are denoted by the same or equivalent reference numerals throughout the drawings. However, it should be noted that the drawings are schematic and different from the actual ones. Also, there are parts where the dimensional relationships and ratios are different between the drawings.

[0016] Also, the embodiments shown below are examples of devices for embodying the technical idea of this invention, and the technical idea of this invention does not specify the arrangement of each component part as follows. The technical idea of this invention can be variously modified within the scope of the claims.

[0017] The following describes a point cloud data generation system equipped with a point cloud data generation device, which is one embodiment of the present invention.

[0018] Figure 1 is a schematic diagram showing the general configuration of a point cloud data generation system, which is one embodiment of the present invention.

[0019] As shown in Figure 1, the point cloud data generation system 100 comprises a point cloud data generation device 1, a point cloud data acquisition device 2, a trolley (mobile body) 3, and a monitor 5.

[0020] The point cloud data acquisition device 2 is mounted on a trolley 3 that moves along the rails 4. While the trolley 3 is moving, the point cloud data acquisition device 2 irradiates laser light onto geographical features around the trolley 3. The point cloud data acquisition device 2 then generates the three-dimensional coordinates of the geographical features as point cloud data based on the reflected light of the irradiated laser beam. Geographical features refer to all objects on the ground, such as tunnels, traffic lights, signs, and trees.

[0021] The point cloud data generation device 1 acquires point cloud data and movement data from the point cloud data acquisition device 2, evaluates the quality of the acquired point cloud data, and corrects the point cloud data based on the evaluation.

[0022] Monitor 5 displays various screens, including a screen that displays features based on the point cloud data generated by the point cloud data generation device 1.

[0023] <Generation of point cloud data by point cloud data acquisition device 2> Figure 2 is a schematic diagram illustrating the generation of point cloud data by the point cloud data acquisition device 2 included in the point cloud data generation system 100, which is one embodiment of the present invention.

[0024] As shown in Figures 1 and 2, the point cloud data acquisition device 2 comprises a laser scanner 21, a GNSS (Global Navigation Satellite System) 22, an IMU (inertial measurement unit) 23, a data acquisition means 24, a data temporary storage unit 25, and a DMI (Distance Measuring Instrument) 26.

[0025] The laser scanner 21 is located at the rear of the trolley 3 and rotates while emitting laser light in a 360-degree radius. The range of the emitted laser light is in the range of 1m to 100m. For example, it emits laser light at 1MHz while rotating within a 360-degree range at a period of 200Hz. The laser scanner 21 then receives the reflected light of the emitted laser beam and acquires laser data (Time, θ, L) indicating the measurement time of reception and the angle and distance to the object based on the received reflected light.

[0026] GNSS22 acquires positioning (location coordinate) data using signals transmitted from artificial satellites.

[0027] The IMU 23 can detect inertial measurement (attitude) data from the laser scanner 21. The attitude acquired by these IMU 23s is supplied to the data acquisition means 24 as POS (Position and Orientation System) data, corresponding to the position coordinate data acquired by GNSS 22. That is, the POS data includes data (Time, xi, yi, zi, Roll, Pitch, Yaw, α) that shows the reference position and attitude (measurement time, position coordinates, attitude, acceleration) of the IMU 23, combining the position coordinate data from GNSS 22 and the detected attitude. zi is the elevation value from ground level to which the IMU 23 is attached. The IMU 23 also has an accelerometer and detects acceleration. Among the POS data, Yaw generates a first azimuth angle D1 that indicates the direction in which the IMU 23 is moving on the X-Y plane. The first azimuth angle D1 may be calculated by the IMU 23, or it may be calculated by the calculation means 103 described later.

[0028] The position coordinates of the laser scanner 21 relative to the IMU 23 can be expressed as (Δx, Δy, Δz).

[0029] The DMI26 detects the distance traveled by the trolley 3, i.e., the distance traveled by the laser scanner 21, detects the speed of the laser scanner 21 from the distance traveled per unit time, and sends the detected speed (first speed) V1 data to the data acquisition means 24.

[0030] The data collection means 24 collects POS data acquired from the IMU 23, laser data (Time, θ, L) acquired from the laser scanner 21, and movement data (D1, V1) of the first azimuth angle D1 and first velocity V1 of the trolley 3.

[0031] The temporary data storage unit 25 temporarily stores the laser data (Time, θ, L) collected by the data acquisition means 24, the movement data (D1, V1) of the first azimuth angle D1 and first velocity V1 of the trolley 3, and the POS data in association with each other. The stored data is supplied to the point cloud data generation device 1. Here, we describe an example in which the data stored in the temporary data storage unit 25 is supplied from the temporary data storage unit 25 to the point cloud data generation device 1 when the point cloud data generation device 1 and the point cloud data acquisition device 2 are connected, but this is not the only example. For example, the data may be supplied to the point cloud data generation device 1 in real time via a wireless network.

[0032] <Configuration of Point Cloud Data Generation Device 1> Returning to Figure 1, the point cloud data generation device 1 includes a data acquisition means 101, a data storage unit 102, a calculation means 103, a determination means 104, a generation means 105, a display data storage unit 110, and a display control means 111.

[0033] The data acquisition means 101 acquires movement data, POS data, and laser data supplied from the data temporary storage unit 25 of the point cloud data acquisition device 2, and stores them in the data storage unit 102.

[0034] The data storage unit 102 is composed of, for example, a hard disk drive, and stores movement data, POS data, and laser data.

[0035] The calculation means 103 includes a speed calculation means 103A and an azimuth angle calculation means 103B.

[0036] The speed calculation means 103A calculates the speed of the laser scanner 21 as a second speed V2 based on the POS data stored in the data storage unit 102, that is, data (Time, xi, yi, zi, Roll, Pitch, Yaw, α) indicating the position and attitude of the IMU 23 (measurement time, position coordinates, attitude, acceleration). Specifically, in the GNSS positioning area, where satellite positioning is possible, the speed calculation means 103A calculates the speed of the laser scanner 21 as a second speed V2 based on a plurality of position coordinates (xi, yi, zi) acquired by the data acquisition means 101. Furthermore, in the non-GNSS positioning area, where satellite positioning is difficult, the speed calculation means 103A calculates the direction of movement based on the attitude (Roll, Pitch, Yaw), and calculates the speed of the laser scanner 21 as a second speed V2 based on the calculated direction of movement and the distance traveled obtained by integrating the acceleration α twice. Note that the GNSS positioning area and the non-GNSS positioning area are predetermined.

[0037] As mentioned above, this calculated second velocity V2 is obtained by integrating the positioning (location coordinates) data from GNSS22 and the inertial measurement (attitude, acceleration) data detected by IMU23.

[0038] The inertial measurement (attitude, acceleration) data (Roll, Pitch, Yaw, α) detected by the IMU23 contains errors. Therefore, in areas with poor visibility above the ground where GNSS positioning is difficult, such as tunnels (non-GNSS positioning areas), distance and azimuth (Yaw) are continuously accumulated without correcting for errors, resulting in the accumulation of distance errors (position errors) and azimuth errors over time. Errors in acceleration data from inertial measurement (attitude, acceleration) become velocity errors, errors in azimuth angular velocity become azimuth errors, and ultimately become position errors, which accumulate in non-GNSS positioning areas.

[0039] In areas with good visibility above ground where positioning is possible (GNSS positioning area), these acceleration and azimuth angular velocity errors are corrected by GNSS22 positioning (position coordinate) data, so the errors in acceleration and azimuth angular velocity do not accumulate in the GNSS positioning area.

[0040] Figure 3 is an explanatory diagram that schematically illustrates the occurrence of errors. Figure 3(a) shows an example of point cloud data (X,Y,Z) when the speed of the trolley 3 (speed of the laser scanner 21) is accurately calculated, Figure 3(b) shows an example of point cloud data (X,Y,Z) when the second speed V is calculated as a speed slower than the actual speed of the trolley 3, and Figure 3(c) shows an example of point cloud data (X,Y,Z) when the second speed V is calculated as a speed faster than the actual speed of the trolley 3.

[0041] As shown in Figure 3(a), if the speed of the trolley 3 is calculated accurately, regardless of whether the point cloud data acquisition device 2 is at position 2A, 2B, or 3C, point cloud data (X, Y, Z) is generated based on the appropriately calculated second speed V, so that the utility pole, object A1, is appropriately reproduced.

[0042] On the other hand, as shown in Figure 3(b), if the second speed V is calculated as a speed slower than the actual speed of the trolley 3, the point cloud data (X,Y,Z) is generated in such a way that the distance per unit time is shorter than in reality, resulting in a reproduction where the object A2 is tilted in the opposite direction of travel (rearward).

[0043] Furthermore, as shown in Figure 3(c), if the second velocity V is calculated as a speed faster than the actual speed of the trolley 3, the point cloud data (X,Y,Z) is generated such that the distance per unit time is longer than in reality, resulting in a reproduction that tilts in the direction of travel (forward), as shown in feature A2.

[0044] The determination means 104 includes a speed determination means 104A and an azimuth angle determination means 104B.

[0045] The speed determination means 104A determines that distortion occurs in the direction of movement of the point cloud data acquisition device 2 when the difference (speed difference) between the second speed V2 calculated by the speed calculation means 103A and the first speed V1 detected by the DMI 26 is greater than or equal to a predetermined speed threshold ThV.

[0046] Figure 4 is an explanatory diagram illustrating the processing performed by the velocity determination means 104A of a point cloud data generation system 100, which is one embodiment of the present invention. Figure 4(a) is a diagram comparing the first velocity V1 and the second velocity V2, and Figure 4(b) is a diagram showing the difference between the first velocity V1 and the second velocity V2.

[0047] Figure 4(a) shows the transition between the first speed V1 detected by the DMI 26 and the second speed V2 calculated by the speed calculation means 103A. Figure 4(b) shows the difference between the first speed V1 detected by the DMI 26 and the second speed V2 calculated by the speed calculation means 103A. Here, the value obtained by subtracting the first speed V1 from the second speed V2 is shown.

[0048] In the GNSS positioning domain, the first velocity V1 and the second velocity V2 coincide. However, in non-GNSS positioning domains, such as at time points t1 and t2, the first velocity V1 and the second velocity V2 may not coincide.

[0049] When the first velocity V1 and the second velocity V2 do not coincide, such as at time t1 or t2, the difference (velocity difference) DV between the first velocity V1 and the second velocity V2 will peak, for example, at time t1 or t2, as shown in Figure 4(b).

[0050] Here, at time t2, the value obtained by subtracting the first velocity V1 from the second velocity V2 is less than or equal to -ThV, that is, the difference DV between the first velocity V1 and the second velocity V2 is greater than or equal to a predetermined velocity threshold ThV.

[0051] Therefore, the speed determination means 104A determines that at time t2, distortion occurs in the direction of movement of the point cloud data acquisition device 2.

[0052] In the GNSS positioning area, the azimuth angle calculation means 103B calculates the azimuth angle of the laser scanner 21 as the first azimuth angle D1 based on multiple position coordinates and attitude data, i.e., multiple POS data (Time, xi, yi, zi, Roll, Pitch, Yaw, α) stored in the data storage unit 102.

[0053] Furthermore, in non-GNSS positioning areas, the azimuth angle calculation means 103B calculates the azimuth angle of the laser scanner 21 as the first azimuth angle D1 based on the attitude acquired by the data acquisition means 101. Specifically, since the azimuth angle (Yaw) among the attitude angles (Roll, Pitch, Yaw) detected by the gyroscope of the IMU 23 indicates the direction of movement, the azimuth angle calculation means 103B calculates this as the first azimuth angle D1.

[0054] The azimuth angle calculation means 103B calculates a vector connecting multiple position coordinates based on the multiple position coordinates acquired by the data acquisition means 101, and calculates the direction of the calculated vector, i.e., the azimuth angle (angle relative to local direction) in which the point cloud data acquisition device 2 moves, as the second azimuth angle. Specifically, the calculation means 103 calculates the azimuth angle (angle relative to local direction) in which the point cloud data acquisition device 2 moves, as the second azimuth angle D2, based on Time, xi, yi, zi of the POS data (Time, xi, yi, zi, Roll, Pitch, Yaw, α) stored in the data storage unit 102.

[0055] The azimuth angle determination means 104B determines that distortion occurs in the direction perpendicular to the movement direction of the trolley 3 in the point cloud data if the difference (azimuth angle difference) between the first azimuth angle D1 and the second azimuth angle D2 calculated by the calculation means 103 is greater than or equal to a predetermined azimuth angle threshold ThD.

[0056] Figure 5 shows the difference (azimuth angle difference) DD between the first azimuth angle D1 and the second azimuth angle D2, calculated by the calculation means 103 of the point cloud data generation system 100, which is one embodiment of the present invention. Here, the value obtained by subtracting the first azimuth angle D1 from the second azimuth angle D2 is shown.

[0057] In GNSS positioning areas, the first azimuth angle D1 and the second azimuth angle D2 coincide. However, in non-GNSS positioning areas, such as at time t11 or t12, the first azimuth angle D1 and the second azimuth angle D2 do not coincide, and the difference DD between the first azimuth angle D1 and the second azimuth angle D2 may not be "0".

[0058] The difference DD between the first azimuth angle D1 and the second azimuth angle D2 peaks, for example, at time t11 or t12.

[0059] Here, at time t12, the difference DD is below -ThD, which means that at time t12, the difference DD between the first azimuth angle D1 and the second azimuth angle D2 is greater than or equal to the predetermined velocity threshold ThD, that is, the value obtained by subtracting the first azimuth angle D1 from the second azimuth angle D2 is less than or equal to -ThD.

[0060] Therefore, the azimuth angle determination means 104B determines that at time t12, distortion occurs in the direction perpendicular to the direction of movement of the trolley 3 in the point cloud data, that is, in the transverse direction.

[0061] If the speed determination means 104A determines that no distortion occurs in the direction of movement of the point cloud data acquisition device 2, the generation means 105 generates point cloud data using POS data based on the second speed V2. On the other hand, if the speed determination means 104A determines that distortion occurs in the direction of movement of the point cloud data acquisition device 2, the generation means 105 corrects the position coordinates of the POS data by replacing the second speed V2 with the first speed V1 and generates point cloud data.

[0062] Figure 6 is a diagram comparing the point cloud data before correction and the point cloud data after correction by the generation means 105 when distortion occurs in the direction of movement in a point cloud data generation system 100, which is one embodiment of the present invention. Figure 6(a) shows an example of the point cloud data before correction, and Figure 6(b) shows an example of the point cloud data after correction.

[0063] Figure 6(a) shows the top view G101 and the side view G102 of the uncorrected point cloud data. Here, the direction of travel is from left to right on the page.

[0064] If the second speed V is calculated as a speed slower than the actual speed of the bogie 3, the point cloud data (X,Y,Z) will be generated in such a way that the distance per unit time is shorter than it actually is, resulting in a reproduction where the terrain is tilted in the opposite direction of travel (rearward), as shown in area A101 of the side view G102.

[0065] Furthermore, if the second speed V is calculated as a speed faster than the actual speed of the bogie 3, the point cloud data (X,Y,Z) will be generated in such a way that the distance per unit time is longer than it actually is, resulting in a reproduction that is tilted in the direction of travel (forward), as shown in area A102 of the side view G102.

[0066] On the other hand, Figure 6(b) shows the top view G201 of the corrected point cloud data and the side view G202 of the corrected point cloud data.

[0067] As shown in Figure 6(b), the point cloud data is formed based on the appropriate velocity after correction, so as shown in the top view G201 and the side view G202, the point cloud data does not tilt forward or backward and can be reproduced as appropriate point cloud data.

[0068] Furthermore, if the azimuth angle determination means 104B determines that no distortion occurs in a direction perpendicular to the movement direction of the point cloud data acquisition device 2, the generation means 105 generates point cloud data based on the first azimuth angle D1.

[0069] On the other hand, if the generation means 105 determines that distortion occurs in a direction perpendicular to the movement direction of the point cloud data acquisition device 2 by the azimuth angle determination means 104B, it corrects the first azimuth angle D1 using the second azimuth angle D2 and generates point cloud data based on the corrected first azimuth angle.

[0070] Specifically, the generation means 105 corrects the first azimuth angle D1 using the following (formula). As a result, HeadingAF = COG, so the generation means 105 corrects by replacing the first azimuth angle D1 with the second azimuth angle D2. HeadingAF=HeadingBF-(HeadingBF-COG) (formula) (HeadingAF is the first azimuth angle D1 after correction, HeadingBF is the first azimuth angle D1 before correction, and COG is the second azimuth angle D2)

[0071] Figure 7 is a diagram comparing the uncorrected point cloud data and the corrected point cloud data in a point cloud data generation system 100, which is one embodiment of the present invention, when distortion occurs in a direction orthogonal to the direction of movement.

[0072] Figure 7 is a cross-sectional view showing the front view G301 of the uncorrected point cloud data, the cross-sectional view G302 showing the tunnel wall position based on the corrected point cloud data, and the cross-sectional views G303 and G304 showing the tunnel wall position based on the uncorrected point cloud data. Cross-sectional view G304 corresponds to the front view G301.

[0073] For comparison, the reference position R101 on the tunnel wall surface in cross-sectional diagrams G302, G303, and G304 shows the tunnel wall surface in a state where no distortion has occurred.

[0074] If there is a discrepancy in the actual azimuth angle of the bogie 3, it may be reproduced as tilted to the right with respect to the wall reference position R101 in a cross section perpendicular to the direction of travel, as shown by wall position R203 in the front view G301 and cross section G304, or tilted to the left with respect to the wall reference position R101 in a cross section perpendicular to the direction of travel, as shown by wall position R202 in cross section G303.

[0075] On the other hand, as corrected, the wall reference position R101 and the wall position R201 coincide, as shown in cross-sectional view G302.

[0076] Thus, when the generation means 105 determines that distortion occurs in a direction perpendicular to the direction of movement of the point cloud data acquisition device 2, it corrects the first azimuth angle D1 using the second azimuth angle D2 and generates point cloud data based on the corrected first azimuth angle D1. This eliminates distortion in the direction perpendicular to the direction of movement of the point cloud data acquisition device 2, and allows for the reproduction of appropriate point cloud data.

[0077] The display data storage unit 110 stores the point cloud data generated by the generation means 105.

[0078] The display control means 111 displays features and other objects on the monitor 5 based on the point cloud data stored in the display data storage unit 110.

[0079] Figure 8 is a flowchart showing the processing steps in a point cloud data generation system 100, which is one embodiment of the present invention.

[0080] In step S101, the data acquisition means 101 acquires movement data, POS data, and laser data supplied from the data temporary storage unit 25 of the point cloud data acquisition device 2, and stores them in the data storage unit 102.

[0081] In step S103, the speed calculation means 103A calculates the speed of the laser scanner 21 as the second speed V2 based on the POS data stored in the data storage unit 102.

[0082] In step S105, the azimuth angle calculation means 103B calculates the azimuth angle of the laser scanner 21 as the first azimuth angle D1 based on a plurality of POS data stored in the data storage unit 102.

[0083] In step S107, the speed determination means 104A determines whether the difference between the second speed V2 calculated by the speed calculation means 103A and the first speed V1 detected by the DMI 26 is greater than or equal to a predetermined speed threshold ThV.

[0084] If it is determined that the difference between the second speed V2 and the first speed V1 is greater than or equal to a predetermined speed threshold ThV (step S107; YES), the speed determination means 104A determines that distortion occurs in the direction of movement of the point cloud data acquisition device 2. In step S109, if the speed determination means 104A determines that distortion occurs in the direction of movement of the point cloud data acquisition device 2, the generation means 105 corrects the position coordinates of the POS data by replacing the second speed V2 with the first speed V1.

[0085] In step S111, the azimuth angle determination means 104B determines whether the difference between the first azimuth angle D1 calculated by the calculation means 103 and the second azimuth angle D2 calculated by the calculation means 103 is greater than or equal to a predetermined azimuth angle threshold ThD.

[0086] If it is determined that the difference between the first azimuth angle D1 and the second azimuth angle D2 is greater than or equal to a predetermined azimuth angle threshold ThD (step S111; YES), the azimuth angle determination means 104B determines that distortion occurs in a direction perpendicular to the movement direction of the point cloud data acquisition device 2, and in step S113, the generation means 105 corrects the first azimuth angle D1 using the second azimuth angle D2.

[0087] In step S115, the generation means 105 generates point cloud data based on the second velocity V2 and the first azimuth angle. Specifically, the generation means 105 generates the data by integrating distance data acquired by the laser scanner 21 with travel trajectory data corrected for the constantly changing position and attitude of the laser scanner 21, based on the second velocity V2 and the first azimuth angle.

[0088] As described above, the point cloud data generation system 100, which is one embodiment of the present invention, includes a data acquisition means 101 that acquires the position coordinates of the laser scanner 21 detected by the GNSS 22 / IMU 23 and the orientation of the laser scanner 21; a calculation means 103 that calculates the azimuth angle at which the trolley 3 moves based on the orientation acquired by the data acquisition means 101 as a first azimuth angle, and calculates the azimuth angle at which the trolley 3 moves based on a plurality of position coordinates acquired by the data acquisition means 101 as a second azimuth angle; and a determination means 104 that determines that distortion occurs in the direction perpendicular to the direction of movement of the trolley 3 in the point cloud data when the difference between the first azimuth angle D1 calculated by the calculation means 103 and the second azimuth angle D2 calculated by the calculation means 103 is greater than or equal to a predetermined azimuth angle threshold ThD.

[0089] This allows us to determine whether or not distortion occurs in the direction perpendicular to the movement direction of the trolley 3 (the transverse direction) of the point cloud data used to detect features, thereby enabling us to evaluate the quality of the laser point cloud.

[0090] Furthermore, the point cloud data generation system 100 includes a data acquisition means 101 that acquires the position coordinates and acceleration of the laser scanner detected by the GNSS 22 / IMU 23 and a first velocity V1 which is the speed of the laser scanner 21; a calculation means 103 that calculates the speed of the laser scanner as a second velocity based on the position coordinates and acceleration acquired by the data acquisition means 101; and a determination means 104 that determines that distortion occurs in the direction of movement of the point cloud data trolley 3 when the difference between the second velocity V2 calculated by the calculation means 103 and the first velocity V1 acquired by the data acquisition means 101 is greater than or equal to a predetermined velocity threshold ThV.

[0091] This allows us to determine whether or not distortion occurs in the direction of movement of the point cloud data cart 3 used for detecting geographic features, thereby enabling us to evaluate the quality of the laser point cloud.

[0092] Furthermore, the above-described embodiment can also be realized by running a program installed on a computer. [Explanation of Symbols]

[0093] 1. Point cloud data generation device 2-point cloud data acquisition device 3. Trolley (mobile unit) 5 monitors 21 Laser Scanners 24 Data Collection Methods 25 Data Temporary Storage Unit 100-point cloud data generation system 101 Data acquisition method 102 Data Storage Unit 103 Calculation method 103A Speed ​​calculation means 103B Azimuth calculation means 104 Judgment means 104A Speed ​​judgment means 104B Azimuth determination means 105 Generation means 110 Display data storage unit 111 Display control means

Claims

1. A point cloud data generation device that generates the three-dimensional coordinates of geographic features as point cloud data based on the reflected light of laser beams emitted from a laser scanner mounted on a mobile body onto geographic features in the vicinity of the mobile body, An acquisition means for acquiring the position coordinates of the laser scanner detected by the detection means and the orientation of the laser scanner, A calculation means that calculates the azimuth angle at which the moving body moves based on the posture acquired by the acquisition means as the first azimuth angle, calculates a vector connecting a plurality of position coordinates acquired by the acquisition means, and calculates the direction of the calculated vector as the second azimuth angle, which is the azimuth angle at which the moving body moves, A determination means that determines that distortion occurs in the point cloud data in a direction perpendicular to the direction of movement of the moving object when the difference between the first azimuth angle calculated by the calculation means and the second azimuth angle calculated by the calculation means is greater than or equal to a predetermined azimuth angle threshold, If the determination means determines that no distortion occurs, the point cloud data is generated based on the first azimuth angle; if the determination means determines that distortion occurs, the first azimuth angle is corrected using the second azimuth angle, and the point cloud data is generated by integrating the corrected first azimuth angle, the corrected driving trajectory data of the laser scanner with the corrected position and orientation, and the distance data acquired by the laser scanner. A point cloud data generation device characterized by being equipped with the following features.

2. A point cloud data generation system comprising a laser scanner mounted on a mobile body and receiving reflected light from laser beams irradiated onto geographical features around the mobile body, and generating the three-dimensional coordinates of the geographical features as point cloud data based on the received reflected light, Positioning means for detecting the position coordinates of the laser scanner, A posture detection means for detecting the posture of the laser scanner, A calculation means that calculates the azimuth angle of the moving body as a first azimuth angle based on the posture detected by the posture detection means, calculates a vector connecting a plurality of position coordinates obtained by the positioning means, and calculates the direction of the calculated vector as a second azimuth angle, which is the azimuth angle of the moving body. A determination means that determines that distortion occurs in the point cloud data in a direction perpendicular to the direction of movement of the moving object when the difference between the first azimuth angle calculated by the calculation means and the second azimuth angle calculated by the calculation means is greater than or equal to a predetermined azimuth angle threshold, If the determination means determines that no distortion occurs, the point cloud data is generated based on the first azimuth angle; if the determination means determines that distortion occurs, the first azimuth angle is corrected using the second azimuth angle, and the point cloud data is generated by integrating the corrected first azimuth angle, the corrected driving trajectory data of the laser scanner with the corrected position and orientation, and the distance data acquired by the laser scanner. A point cloud data generation system characterized by having the following features.

3. A point cloud data generation program executed by a point cloud data generation device that generates the three-dimensional coordinates of geographic features as point cloud data based on the reflected light of laser light emitted from a laser scanner mounted on a mobile body onto geographic features around the mobile body, An acquisition step of acquiring the position coordinates of the laser scanner detected by the detection means and the orientation of the laser scanner, A calculation step which calculates the azimuth angle of the moving body as the first azimuth angle based on the posture acquired in the acquisition step, calculates a vector connecting the multiple position coordinates acquired in the acquisition step, and calculates the direction of the calculated vector as the second azimuth angle, which is the azimuth angle of the moving body; A determination step in which, if the difference between the first azimuth angle calculated in the calculation step and the second azimuth angle calculated in the calculation step is greater than or equal to a predetermined azimuth angle threshold, it is determined that distortion occurs in the point cloud data in a direction perpendicular to the direction of movement of the moving object, If the determination step determines that the distortion does not occur, the point cloud data is generated based on the first azimuth angle; if the determination step determines that the distortion occurs, the first azimuth angle is corrected using the second azimuth angle, and the point cloud data is generated by integrating the corrected first azimuth angle, the corrected driving trajectory data with the corrected position and orientation of the laser scanner, and the distance data acquired by the laser scanner. A point cloud data generation program characterized by causing the point cloud data generation device to execute the following.

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