A point cloud performance test system and test method in laser radar motion scene

Abstract

The present invention discloses a point cloud performance test system and test method under a laser radar motion scene, which belongs to the field of vehicle-mounted radar testing. The point cloud performance test system under the laser radar motion scene includes a reflector, a laser radar, a track, a reflector motion platform, a radar motion platform, a controller, an adapter and a host computer; the reflector is fixed on the reflector motion platform, the laser radar is fixed on the radar motion platform, the light-emitting surface of the laser radar faces the reflector, and the reflector motion platform and the radar motion platform move on the track respectively; the reflector motion platform and the radar motion platform are both electrically connected to the controller. The present invention provides a point cloud performance test system and test method under a laser radar motion scene. Under the premise of ensuring the safety of the test personnel, the motion scene can be set arbitrarily, and the environment is simple and convenient to build. The shape, motion state and true distance value of the target can be known in advance, which is convenient for evaluating the point cloud performance.

Description

Technical Field

[0001] The present invention relates to a point cloud performance test system and a test method in a laser radar motion scene, belonging to the field of vehicle-mounted radar testing. Background Art

[0002] At present, with the development of automobile autonomous driving technology, vehicles have put forward higher precision requirements for environmental perception. LiDAR has become a key sensor for realizing high-level autonomous driving with its high-precision advantage. The scanning frequency of LiDAR is usually 10Hz, that is, it takes 0.1s to obtain a frame of point cloud. During this period, if the vehicle speed is 100km / h, the movement distance is close to 2.8m. In motion scenes, such as when the vehicle is driving at high speed or turning, due to the movement distance of the vehicle, the starting point cloud and the ending point cloud in a frame of point cloud can only be obtained in different coordinate systems, which causes the point cloud to be distorted. In order to solve the above problems, it is necessary to compensate for the motion distortion. At the same time, a test method is also needed to verify the compensation effect and the ranging accuracy in the motion scene. At present, the actual vehicle test method is usually used to verify its point cloud performance on real roads.

[0003] To conduct real vehicle testing on real roads, first of all, it is necessary to install the LiDAR on the real vehicle, which involves the installation of luggage racks, turntables and LiDAR, as well as the external parameter calibration of LiDAR, which is expensive, time-consuming and labor-intensive. Secondly, it is also easily affected by the road environment. Considering the safety of testers, it is impossible to set the motion scene arbitrarily; finally, there are many targets on the real road, such as vehicles, pedestrians, guardrails, etc. The shapes and motion states of the targets are different, and the true distance value cannot be clearly determined, so it is difficult to evaluate the point cloud performance. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a laser radar point cloud performance test system and test method in a motion scene. Under the premise of ensuring the safety of the tester, the motion scene can be set arbitrarily, and the environment construction is simple and convenient. The shape, motion state and true distance value of the target can be known in advance, which is convenient for evaluating the point cloud performance.

[0005] In order to solve the above technical problems, the technical solution of the present invention is:

[0006] On one hand, the present invention provides a point cloud performance test system in a laser radar motion scene, which includes a reflector, a laser radar, a track, a reflector motion platform, a radar motion platform, a controller, an adapter and a host computer;

[0007] The reflector is fixed on the reflector motion platform, the laser radar is fixed on the radar motion platform, the light emitting surface of the laser radar faces the reflector, and the reflector motion platform and the radar motion platform move on the track respectively;

[0008] The reflector motion platform and the radar motion platform are both electrically connected to the controller, and the controller is electrically connected to the host computer;

[0009] The laser radar is electrically connected to the host computer through an adapter.

[0010] Furthermore, the reflector motion platform includes a first electric translation platform, a first electric rotating platform and a reflector, wherein the first electric translation platform is used to move on a track, the first electric rotating platform is fixed on the first electric translation platform, the reflector is fixed on the first electric rotating platform, and the first electric translation platform and the first electric rotating platform are both electrically connected to the controller.

[0011] Furthermore, the radar motion platform includes a second electric displacement platform, a lifting platform, a second electric rotating platform and a laser radar. The second electric displacement platform is used to move on a track. The lifting platform is fixed on the second electric displacement platform. The second electric rotating platform is fixed on the lifting platform. The laser radar is fixed on the second electric rotating platform. The second electric displacement platform, the lifting platform and the second electric rotating platform are all electrically connected to the controller.

[0012] Furthermore, the reflection plate is a Lambertian diffuse reflection plate.

[0013] Furthermore, the plane of the reflector is perpendicular to the ground, and the bottom surface of the laser radar is parallel to the ground.

[0014] Furthermore, the host computer includes a displacement control module, a rotation control module, a true value acquisition module and a point cloud processing module;

[0015] The displacement control module is used to control the displacement of the first electric displacement stage and the second electric displacement stage, thereby driving the displacement of the laser radar and the reflector;

[0016] The rotation control module is used to control the rotation of the first electric rotating platform and the second electric rotating platform, thereby driving the rotation of the laser radar and the reflector;

[0017] The true value acquisition module is used to calculate the distance between the laser radar and the reflector through the motion model, and use the distance between the laser radar and the reflector as the true value of the distance;

[0018] The point cloud processing module is used to obtain point cloud data obtained by the laser radar scanning the reflector, fit the plane of the reflector and calculate the angle between the fitted plane and the ground, and judge whether the motion distortion compensation effect meets the expected requirements through the deviation between the angle between the fitted plane and the ground and the preset angle range; at the same time, the distance measurement accuracy of the laser radar in the motion scene is verified through the difference between the distance measurement value of the reflector and the true value of the distance.

[0019] Another aspect of the present invention provides a method for testing the point cloud performance test system in a laser radar motion scene, which comprises the following steps:

[0020] Step S1, inputting corresponding displacement and rotation parameters through the host computer to preset the motion scene;

[0021] Step S2, start the laser radar, the reflector motion platform and the radar motion platform;

[0022] Step S3: The laser radar scans the reflector to obtain point cloud data;

[0023] Step S4, the host computer obtains the true value of the distance measurement and processes the point cloud data;

[0024] Step S5: The host computer verifies the motion distortion compensation effect and the ranging accuracy.

[0025] Furthermore, in step S4, the host computer obtains the true value of the distance measurement, which specifically includes the following steps:

[0026] The host computer calculates the distance between the laser radar and the reflector through the motion model and uses it as the true value of the distance;

[0027] When the laser radar and reflector are in uniform linear motion:

[0028] The preset initial interval distance is d0;

[0029] The distance traveled by the reflector under uniform linear motion is d R1 =v R t, where v R is the displacement speed of the preset reflector, and t is the displacement time of the reflector;

[0030] The movement distance of the laser radar under uniform linear motion is d L1 =v L t, where v L is the preset displacement speed of the laser radar, and t is the displacement time of the laser radar;

[0031] Then, the distance between the laser radar and the reflector during uniform linear motion is the true distance value, and the true distance value d1 is: d1=d R1 -d L1 +d0;

[0032] When the laser radar and reflector are in uniformly accelerated linear motion:

[0033] The preset initial interval distance is d0;

[0034] The distance traveled by the reflector under uniformly accelerated linear motion is d R2 =v R0 t+1 / 2a R t 2 , where v R0 is the preset initial displacement speed of the reflector, a R is the displacement acceleration of the preset reflector, and t is the displacement time of the reflector;

[0035] The movement distance of the laser radar under uniform acceleration linear motion is d L2 =v L0 t+1 / 2a L t 2 , where v L0 is the preset initial displacement speed of the laser radar, a L is the preset displacement acceleration of the laser radar, and t is the displacement time of the laser radar;

[0036] Then, the distance between the laser radar and the reflector during uniformly accelerated linear motion is the true distance value, and the true distance value d2 is: d2=d R2 -d L2 +d0.

[0037] Furthermore, in step S4, processing the point cloud data specifically includes the following steps:

[0038] The point cloud data obtained by scanning the reflector with the laser radar is obtained, the plane of the reflector is fitted, the angle between the fitted plane of the reflector and the ground is calculated, and the distance measurement value of the reflector is obtained.

[0039] Furthermore, in step S5, the host computer verifies the motion distortion compensation effect and the ranging accuracy, which specifically includes the following steps:

[0040] Whether the motion distortion compensation effect meets the expected requirements is judged by the deviation between the calculated angle between the fitting plane and the ground and the preset angle range, and the ranging accuracy of the lidar in the motion scene is verified by the difference between the distance measurement value of the reflector and the true value of the distance.

[0041] The above technical solution is adopted. The present invention builds a motion platform indoors, drives the movement of the laser radar and the reflector by controlling the displacement and rotation of the motion platform, and can arbitrarily set the movement mode and speed of the laser radar and the reflector by inputting corresponding parameters into the host computer, so as to simulate the movement scene of the real car on the real road. The plane of the reflector is fitted based on the point cloud of the reflector and the angle between the reflector plane and the ground is calculated. Because the reflector is a plane and is perpendicular to the ground, this angle should be 90°, but if there is motion distortion, this angle will have deviations. Based on this, the motion distortion compensation effect can be preliminarily verified. By presetting the motion scene by the host computer, the distance between the laser radar and the reflector can be calculated by the motion model, and this can be used as the true value to verify the ranging accuracy of the laser radar in the motion scene. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a structural schematic diagram of a point cloud performance test system in a laser radar motion scene of the present invention;

[0043] Figure 2 It is a principle block diagram of the host computer of the present invention;

[0044] Figure 3 It is a flow chart of a testing method of a point cloud performance testing system in a laser radar motion scene of the present invention;

[0045] Figure 4 It is a schematic diagram of the fitting plane of the reflection plate of the present invention. DETAILED DESCRIPTION

[0046] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments in conjunction with the accompanying drawings.

[0047] Embodiment 1

[0048] like Figure 1 As shown, this embodiment provides a point cloud performance testing system in a laser radar motion scene, which includes a reflector 6, a laser radar 5, a track 1, a reflector motion platform, a radar motion platform, a controller 7, an adapter 8 and a host computer 10, and the entire system is powered by a power supply 9.

[0049] The reflector 6 is fixed on the reflector moving platform, the laser radar 5 is fixed on the radar moving platform, the light emitting surface of the laser radar 5 faces the reflector 6, and the reflector moving platform and the radar moving platform move on the track 1 respectively.

[0050] The reflector motion platform and the radar motion platform are both electrically connected to the controller 7 , and the controller 7 is electrically connected to the host computer 10 .

[0051] The reflector 6 is a Lambertian diffuse reflector 6 , the plane of the reflector 6 is perpendicular to the ground, and the bottom surface of the laser radar 5 is parallel to the ground.

[0052] The laser radar 5 is electrically connected to the host computer 10 via the adapter 8 .

[0053] like Figure 1 As shown, the reflector motion platform of this embodiment includes a first electric translation platform 21, a first electric rotating platform 41 and a reflector 6. The first electric translation platform 21 is used to move on the track 1. The first electric rotating platform 41 is fixed on the first electric translation platform 21. The reflector 6 is fixed on the first electric rotating platform 41. The first electric translation platform 21 and the first electric rotating platform 41 are both electrically connected to the controller 7.

[0054] like Figure 1 As shown, the radar motion platform of this embodiment includes a second electric displacement platform 22, a lifting platform 3, a second electric rotating platform 42 and a laser radar 5. The second electric displacement platform 22 is used to move on the track 1. The lifting platform 3 is fixed on the second electric displacement platform 22, the second electric rotating platform 42 is fixed on the lifting platform 3, and the laser radar 5 is fixed on the second electric rotating platform 42. The second electric displacement platform 22, the lifting platform 3 and the second electric rotating platform 42 are all electrically connected to the controller 7.

[0055] like Figure 2 As shown, the host computer 10 of this embodiment includes a displacement control module, a rotation control module, a true value acquisition module and a point cloud processing module.

[0056] The displacement control module is used to control the displacement of the first electric displacement platform 21 and the second electric displacement platform 22, thereby driving the displacement of the laser radar 5 and the reflector 6. The controllable displacement parameters include displacement direction, distance, speed, acceleration, etc., so as to simulate the linear motion of the real vehicle.

[0057] The rotation control module is used to control the rotation of the first electric rotating table 41 and the second electric rotating table 42, thereby driving the rotation of the laser radar 5 and the reflector 6. The controllable rotation parameters include rotation direction, angle, speed, etc., so as to simulate the turning movement of the real vehicle.

[0058] The true value acquisition module is used to calculate the distance between the laser radar 5 and the reflector 6 through the motion model, and use the distance between the laser radar 5 and the reflector 6 as the true value of the distance.

[0059] The point cloud processing module is used to obtain the point cloud data obtained by the laser radar 5 scanning the reflector 6, fit the plane of the reflector 6 and calculate the angle between the fitted plane and the ground, and judge whether the motion distortion compensation effect meets the expected requirements through the deviation between the angle between the fitted plane and the ground and the preset angle range; at the same time, the distance measurement accuracy of the laser radar 5 in the motion scene is verified by the difference between the distance measurement value of the reflector 6 and the true value of the distance.

[0060] Embodiment 2

[0061] like Figure 3 As shown, this embodiment provides a method for testing a point cloud performance test system in a laser radar motion scene, which includes the following steps:

[0062] Step S1, inputting corresponding displacement and rotation parameters through the host computer 10 to preset the motion scene;

[0063] Step S2, start the laser radar 5, the reflector motion platform and the radar motion platform;

[0064] Step S3, the laser radar 5 scans the reflector 6 to obtain point cloud data;

[0065] Step S4, the host computer 10 obtains the true value of the distance measurement and processes the point cloud data;

[0066] Step S5: The host computer 10 verifies the motion distortion compensation effect and the ranging accuracy.

[0067] In step S4 of this embodiment, the host computer 10 obtains the true value of the distance measurement, which specifically includes the following steps:

[0068] The host computer 10 calculates the distance between the laser radar 5 and the reflector 6 through the motion model and uses it as the true value of the distance;

[0069] When the laser radar 5 and the reflector 6 are in uniform linear motion:

[0070] The preset initial interval distance is d0;

[0071] The moving distance of the reflector 6 under uniform linear motion is d R1 =v R t, where v R is the preset displacement speed of the reflector 6, and t is the displacement time of the reflector 6;

[0072] The movement distance of the laser radar 5 under uniform linear motion is d L1 =v L t, where v L is the preset displacement speed of the laser radar 5, and t is the displacement time of the laser radar 5;

[0073] Then, the distance between the laser radar 5 and the reflector 6 during the uniform linear motion is the true distance value, and the true distance value d1 is: d1=d R1 -d L1 +d0;

[0074] When the laser radar 5 and the reflector 6 are in uniformly accelerated linear motion:

[0075] The preset initial interval distance is d0;

[0076] The moving distance of the reflector 6 under uniform accelerated linear motion is d R2 =v R0 t+1 / 2a R t 2 , where v R0 is the preset initial displacement speed of the reflector 6, a R is the preset displacement acceleration of the reflector 6, and t is the displacement time of the reflector 6;

[0077] The movement distance of the laser radar 5 under uniform acceleration linear motion is d L2 =v L0 t+1 / 2a L t 2 , where v L0 is the preset initial displacement speed of the laser radar 5, a L is the preset displacement acceleration of the laser radar 5, and t is the displacement time of the laser radar 5;

[0078] Then, the distance between the laser radar 5 and the reflector 6 during the uniformly accelerated linear motion is the true distance value, and the true distance value d2 is: d2=d R2 -d L2 +d0.

[0079] In step S4 of this embodiment, processing the point cloud data specifically includes the following steps:

[0080] The point cloud data obtained by the laser radar 5 scanning the reflector 6 is obtained, the plane of the reflector 6 is fitted, and the angle between the fitted plane of the reflector 6 and the ground is calculated to obtain the distance measurement value of the reflector 6. Because the laser beam emitted by the laser radar 5 has a horizontal angle and a vertical angle, the distance measurement value of the point on the reflector 6 hit by the laser radar 5 should be converted into the distance value from the laser radar 5 to the center point of the reflector 6.

[0081] In step S5 of this embodiment, the host computer 10 verifies the motion distortion compensation effect and the ranging accuracy, which specifically includes the following steps:

[0082] The calculated angle between the fitting plane and the ground and the deviation of the preset angle range are used to determine whether the motion distortion compensation effect meets the expected requirements, and the distance measurement accuracy of the laser radar 5 in the motion scene is verified by the difference between the distance measurement value of the reflector 6 and the true distance value. In addition, when the verification fails, the host computer 10 can automatically save the current motion scene parameters and point cloud data to analyze the cause of the problem.

[0083] The fitting plane of this embodiment is as follows Figure 4 As shown, the scenario in which the laser radar 5 moves and the reflector 6 is stationary is used as an example for explanation:

[0084] In the scene where the laser radar 5 is stationary, the reflector 6 is a plane and is perpendicular to the ground, so the fitted reflector 6 plane will be as follows: Figure 4 As shown by the solid line in , the angle α between it and the ground should be 90°.

[0085] In the moving scene of the laser radar 5, since the laser radar 5 does not emit all laser beams at the same time, the first point of a frame may hit the top of the reflector 6, and as the laser radar 5 moves, the last point of this frame may hit the bottom of the reflector 6. At this time, it is equivalent to the laser radar 5 approaching the reflector 6 for a distance, and the distance of the last point will appear to be closer than the distance of the first point.

[0086] So the fitted plane will be like Figure 4 As shown by the dotted line in , the angle θ between the laser radar 5 and the ground will deviate from α, which means that the shape of the reflector 6 scanned by the laser radar 5 is inconsistent with the shape of the real reflector 6, and the motion distortion compensation is to eliminate this problem. Considering the errors caused by the ranging and fitting plane of the laser radar 5 itself, a deviation range can be preset, for example, the preset angle range is 89° to 91°. If it exceeds this range, it is considered that the motion distortion compensation effect does not meet the expected requirements.

[0087] The specific embodiments described above further illustrate the technical problems, technical solutions and beneficial effects solved by the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A point cloud performance test system for laser radar motion scenes, characterized by: It includes a reflector (6), a laser radar (5), a track (1), a reflector motion platform, a radar motion platform, a controller (7), an adapter (8) and a host computer (10); The reflector (6) is fixed on a reflector motion platform, the laser radar (5) is fixed on a radar motion platform, the light emitting surface of the laser radar (5) faces the reflector (6), and the reflector motion platform and the radar motion platform move on the track (1) respectively; The reflector motion platform and the radar motion platform are both electrically connected to a controller (7), and the controller (7) is electrically connected to a host computer (10); The laser radar (5) is electrically connected to the host computer (10) via an adapter (8); The host computer (10) comprises a displacement control module, a rotation control module, a true value acquisition module and a point cloud processing module; The displacement control module is used to control the displacement of the first electric displacement platform (21) and the second electric displacement platform (22), thereby driving the displacement of the laser radar (5) and the reflector (6); The rotation control module is used to control the rotation of the first electric rotating platform (41) and the second electric rotating platform (42), thereby driving the rotation of the laser radar (5) and the reflector (6); The true value acquisition module is used to calculate the distance between the laser radar (5) and the reflector (6) through a motion model, and use the distance between the laser radar (5) and the reflector (6) as the true value of the distance; The point cloud processing module is used to obtain point cloud data obtained by the laser radar (5) scanning the reflector (6), fit the plane of the reflector (6) and calculate the angle between the fitted plane and the ground, and judge whether the motion distortion compensation effect meets the expected requirements through the deviation between the angle between the fitted plane and the ground and the preset angle range; at the same time, the distance measurement accuracy of the laser radar (5) in the motion scene is verified through the difference between the distance measurement value of the reflector (6) and the true value of the distance; The testing method of the point cloud performance testing system in the laser radar motion scene comprises the following steps: Step S1, inputting corresponding displacement and rotation parameters through the host computer (10) to preset the motion scene; Step S2, starting the laser radar (5), the reflector motion platform and the radar motion platform; Step S3, the laser radar (5) scans the reflector (6) to obtain point cloud data; Step S4, the host computer (10) obtains the true value of the distance measurement and processes the point cloud data; Step S5, the host computer (10) verifies the motion distortion compensation effect and the ranging accuracy; In step S4, the host computer (10) obtains the true value of the distance measurement, which specifically includes the following steps: The host computer (10) calculates the distance between the laser radar (5) and the reflector (6) through the motion model and uses the distance as the true value of the distance; When the laser radar (5) and the reflector (6) are in uniform linear motion: The preset initial interval distance is d0; The distance traveled by the reflector (6) under uniform linear motion is d. R1 =v R t, where v R is a preset displacement speed of the reflecting plate (6), and t is the displacement time of the reflecting plate (6); The distance traveled by the laser radar (5) under uniform linear motion is d L1 =v L t, where v L is the preset displacement speed of the laser radar (5), and t is the displacement time of the laser radar (5); Then, the distance between the laser radar (5) and the reflector (6) during the uniform linear motion is the true distance value, and the true distance value d1 is: d1=d R1 -d L1 +d0; When the laser radar (5) and the reflector (6) are in uniformly accelerated linear motion: The preset initial interval distance is d0; The distance traveled by the reflector (6) under uniformly accelerated linear motion is d. R2 =v R0 t+1 / 2a R t 2 , where v R0 is the preset initial displacement speed of the reflector (6), a R is the preset displacement acceleration of the reflecting plate (6), and t is the displacement time of the reflecting plate (6); The distance traveled by the laser radar (5) under uniformly accelerated linear motion is d L2 =v L0 t+1 / 2a L t 2 , where v L0 is the preset initial displacement speed of the laser radar (5), a L is the preset displacement acceleration of the laser radar (5), and t is the displacement time of the laser radar (5); Then, the distance between the laser radar (5) and the reflector (6) during the uniformly accelerated linear motion is the true distance value, and the true distance value d2 is: d2=d R2 -d L2 +d0; In step S4, processing the point cloud data specifically includes the following steps: Obtaining point cloud data obtained by scanning the reflector (6) with a laser radar (5), fitting the plane of the reflector (6), calculating the angle between the fitting plane of the reflector (6) and the ground, and obtaining a distance measurement value of the reflector (6); In step S5, the host computer (10) verifies the motion distortion compensation effect and the ranging accuracy, which specifically includes the following steps: Whether the motion distortion compensation effect meets the expected requirements is judged by calculating the included angle between the fitting plane and the ground and the deviation within the preset angle range, and the ranging accuracy of the laser radar (5) in the motion scene is verified by the difference between the distance measurement value of the reflector (6) and the true distance value.

2. The laser radar point cloud performance test system in motion scene according to claim 1, characterized in that: The reflector plate motion platform comprises a first electric displacement platform (21), a first electric rotation platform (41) and a reflector plate (6); the first electric displacement platform (21) is used to move on a track (1); the first electric rotation platform (41) is fixed on the first electric displacement platform (21); the reflector plate (6) is fixed on the first electric rotation platform (41); and the first electric displacement platform (21) and the first electric rotation platform (41) are both electrically connected to a controller (7).

3. The point cloud performance test system for laser radar motion scenes according to claim 2, characterized in that: The radar motion platform comprises a second electric displacement platform (22), a lifting platform (3), a second electric rotating platform (42) and a laser radar (5); the second electric displacement platform (22) is used to move on the track (1); the lifting platform (3) is fixed on the second electric displacement platform (22); the second electric rotating platform (42) is fixed on the lifting platform (3); the laser radar (5) is fixed on the second electric rotating platform (42); and the second electric displacement platform (22), the lifting platform (3) and the second electric rotating platform (42) are all electrically connected to a controller (7).

4. The laser radar point cloud performance test system in motion scene according to claim 1, characterized in that: The reflection plate (6) is a Lambertian diffuse reflection plate (6).

5. The laser radar point cloud performance test system in motion scene according to claim 1, characterized in that: The plane of the reflection plate (6) is perpendicular to the ground, and the bottom surface of the laser radar (5) is parallel to the ground.

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