Lidar range and angle dynamic testing method

Abstract

The application discloses a kind of laser radar distance and angle dynamic test method, comprising the following steps: two laser radars same height and lateral interval preset distance d x Fixed horizontally on test vehicle, two laser radars are calibrated laser radar and laser radar to be tested respectively;During the movement of test vehicle and target vehicle, two laser radars scan target vehicle to obtain respective scanning data;Theoretical value of scanning data of laser radar to be tested is calculated based on scanning data of calibrated laser radar and translation vector;The deviation between the theoretical value and the measured value of the scanning data of the laser radar to be tested is obtained to obtain the distance and angle accuracy.The laser radar distance and angle dynamic test method takes calibrated laser radar as a reference, and calculates the theoretical value of the scanning data of the laser radar to be tested through the translation vector, so as to obtain the distance and angle deviation.

Description

Technical Field

[0001] This invention relates to the technical field of lidar, and in particular to a dynamic testing method for lidar distance and angle. Background Technology

[0002] LiDAR detects the position of a target by emitting a laser beam and receiving the echo reflected from the target, making the measurement of its distance and angle accuracy particularly important.

[0003] In existing technologies, to test the distance accuracy of a lidar, the distance from the lidar to the reflector is usually measured using a rangefinder or total station as the true distance value; to test the angle accuracy of a lidar, the angle of rotation of the lidar is usually recorded using a turntable as the true angle value.

[0004] The above solution has two main problems: First, it requires the use of a rangefinder or total station and a turntable to obtain the true value; second, if testing is required in a dynamic scenario, an additional motion platform needs to be built, and the required testing area needs to be as large as possible. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] To address this, the present invention proposes a dynamic testing method for lidar distance and angle, which uses a calibrated lidar as a reference and eliminates the need for additional equipment and motion platforms to obtain the true values, enabling testing in dynamic scenarios.

[0007] The dynamic testing method for lidar distance and angle according to an embodiment of the present invention includes the following steps:

[0008] Step 1: Prepare the testing tools: two lidars, one test vehicle, and one target vehicle. The two lidars are a calibrated lidar and a lidar to be tested.

[0009] Step 2: Deploy two lidar units: The two lidar units are at the same height and are horizontally spaced by a preset distance d. x It is horizontally fixed to the test vehicle;

[0010] Step 3: Acquiring Scan Data: During the movement of the test vehicle and the target vehicle, the two lidars scan the target vehicle to acquire their respective scan data;

[0011] Step 4: Calculate the theoretical value: Calculate the theoretical value of the scanning data of the lidar to be tested based on the scanning data and translation vector of the calibrated lidar;

[0012] Step 5: Obtain the distance and angle accuracy of the lidar: The distance and angle accuracy of the lidar under test are obtained by calculating the deviation between the theoretical value and the measured value of the scanning data of the lidar under test.

[0013] The beneficial effects of this invention are that it does not require the use of a rangefinder, total station, or turntable to obtain the true value. Using a calibrated lidar as a reference, the theoretical value of the lidar scanning data to be tested is obtained by calculating the translation vector. The distance and angle accuracy can be obtained based on the deviation between the theoretical value and the measured value. At the same time, the vehicle equipped with lidar can be tested outdoors without the need to build a motion platform or the trouble of indoor environment setup.

[0014] According to one embodiment of the present invention, in the second step, the two lidars are placed horizontally relative to each other to ensure that there is no rotation between their coordinate systems, only translation along the x-axis, and the translation vector is (d x ,0,0), where d x This refers to the preset horizontal spacing.

[0015] According to an embodiment of the present invention, in the fourth step, the coordinates of the measurement point of the target vehicle in the calibrated lidar coordinate system are set as (x1, y1, z1), and the theoretical coordinates of the measurement point of the target vehicle in the lidar coordinate system to be tested are (x2, y2, z2). Since there is no rotation between the coordinate systems of the two lidars, only translation along the x-axis, y2 = y1 and z2 = z1.

[0016] According to one embodiment of the present invention, when the measurement point of the target vehicle is located between two lidars, then |x2|=d x -|x1|, therefore, the theoretical distance between the measurement point of the target vehicle and the lidar under test is [value missing]. The theoretical horizontal angle of the measurement point of the target vehicle relative to the lidar under test is [value missing]. The theoretical vertical angle between the measurement point of the target vehicle and the lidar under test is then...

[0017] According to one embodiment of the present invention, when the measurement point of the target vehicle is located to the left of the two lidars, then |x2|=|x1|+d x Therefore, the theoretical distance between the measurement point of the target vehicle and the lidar under test is [value missing]. The theoretical horizontal angle of the measurement point of the target vehicle relative to the lidar under test is [value missing]. The theoretical vertical angle between the measurement point of the target vehicle and the lidar under test is then...

[0018] According to one embodiment of the present invention, when the measurement point of the target vehicle is located to the right of the two lidars, then |x2|=|x1|-d x Therefore, the theoretical distance between the measurement point of the target vehicle and the lidar under test is [value missing]. The theoretical horizontal angle of the measurement point of the target vehicle relative to the lidar under test is [value missing]. The theoretical vertical angle between the measurement point of the target vehicle and the lidar under test is then...

[0019] According to an embodiment of the present invention, in the fifth step, the distance and angle accuracy can be obtained by calculating the deviation between the theoretical value and the measured value of the scanning data of the lidar to be tested. The distance measurement value of the target vehicle's measurement point relative to the lidar to be tested is the product of the laser flight time t and the speed of light c divided by 2. The angle measurement value of the target vehicle's measurement point relative to the lidar to be tested is the horizontal angle and vertical angle when the laser beam is emitted.

[0020] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the environment setup;

[0024] Figure 2 This is a flowchart of the dynamic testing method for lidar distance and angle;

[0025] Figure 3 This is a diagram of the measurement results. Figure 1 ;

[0026] Figure 4 This is a diagram of the measurement results. Figure 2 ;

[0027] Figure 5 This is a diagram of the measurement results. Figure 3 .

[0028] The labels in the diagram are: 1. Test vehicle; 2. Calibrated lidar; 3. LiDAR to be tested; 4. Target vehicle. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The following describes in detail, with reference to the accompanying drawings, the method for dynamic testing of lidar distance and angle according to an embodiment of the present invention.

[0031] See Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 The dynamic testing method for lidar distance and angle of the present invention includes the following steps:

[0032] Step 1: Prepare the testing tools: two lidars, one test vehicle 1 and one target vehicle 4. The two lidars are the calibrated lidar 2 and the lidar to be tested 3.

[0033] Step 2: Deploy two lidar units: The two lidar units are at the same height and are horizontally spaced by a preset distance d. x The two lidar units are horizontally fixed on test vehicle 1; they are placed horizontally relative to each other to ensure that there is no rotation between their coordinate systems, only translation along the x-axis, and the translation vector is (d...). x ,0,0), where d x This refers to the preset horizontal spacing.

[0034] Step 3: Acquiring Scan Data: During the movement of test vehicle 1 and target vehicle 4, two lidars scan target vehicle 4 to acquire their respective scan data.

[0035] Step 4: Calculate the theoretical values: Based on the scanning data and translation vector of the calibrated LiDAR 2, calculate the theoretical values ​​of the scanning data of the LiDAR 3 under test. Set the coordinates of the measurement point of the target vehicle 4 in the coordinate system of the calibrated LiDAR 2 as (x1, y1, z1), and the theoretical coordinates of the measurement point of the target vehicle 4 in the coordinate system of the LiDAR 3 under test as (x2, y2, z2). Since there is no rotation between the coordinate systems of the two LiDARs, only translation along the x-axis, y2 = y1, z2 = z1. When the measurement point of the target vehicle 4 is located between the two LiDARs, then |x2| = d. x -|x1|, therefore, the theoretical distance between the measurement point of target vehicle 4 and the lidar under test 3 is -|x1|. The theoretical horizontal angle of the measurement point of target vehicle 4 relative to the lidar under test 3 is [value missing]. The theoretical vertical angle between the measurement point of target vehicle 4 and the lidar under test 3 is: When the measurement point of target vehicle 4 is located to the left of the two lidars, then |x2|=|x1|+d x Therefore, the theoretical distance between the measurement point of target vehicle 4 and the lidar under test 3 is [value missing]. The theoretical horizontal angle of the measurement point of target vehicle 4 relative to the lidar under test 3 is [value missing]. The theoretical vertical angle between the measurement point of target vehicle 4 and the lidar under test 3 is: When the measurement point of target vehicle 4 is located to the right of the two lidars, then |x2|=|x1|-d x Therefore, the theoretical distance between the measurement point of target vehicle 4 and the lidar under test 3 is [value missing]. The theoretical horizontal angle of the measurement point of target vehicle 4 relative to the lidar under test 3 is [value missing]. The theoretical vertical angle between the measurement point of target vehicle 4 and the lidar under test 3 is:

[0036] Step 5: Obtaining the distance and angle accuracy of the lidar: The distance and angle accuracy of the lidar 3 under test are obtained by calculating the deviation between the theoretical and measured values ​​of the scanning data. The distance measurement value of the target vehicle 4 relative to the lidar 3 under test is the product of the laser's flight time t and the speed of light c, divided by 2. The angle measurement value of the target vehicle 4 relative to the lidar 3 under test is the horizontal and vertical angles at the time of laser emission.

[0037] Environment setup, such as Figure 1As shown, prepare a test vehicle 1, a calibrated lidar 2, a lidar to be tested 3, and a target vehicle 4. Two lidars are horizontally fixed at the same height on test vehicle 1. One is the calibrated lidar 2, and its measurement value is used as the true value. The other is the lidar to be tested 3. The two lidars are separated by a preset lateral distance d. x The target vehicle 4 is located within the field of view of the two lidar sensors. Firstly, custom-designed fixtures can be used to fix the lidar sensors to the test vehicle 1 to prevent positional shift. Secondly, to ensure accurate measurement results, a clearly visible location on the target vehicle 4 can be selected as the measurement point and marked for identification. Simultaneously, it is crucial to ensure that there are no other interfering objects within the lidar's field of view to avoid affecting data acquisition.

[0038] The measurement steps of the dynamic testing method for lidar distance and angle are as follows: Figure 2 As shown, during the movement of test vehicle 1 and target vehicle 4, two lidar sensors scan target vehicle 4 to acquire their respective scan data. The scan data includes, but is not limited to, xyz coordinate values ​​and intensity values, based on a preset distance d. x By knowing the approximate location of the target vehicle 4, the translation vector between the coordinate systems of the two lidars can be determined. Based on the measured values ​​of the scan data of the calibrated lidar 2, the theoretical values ​​of the scan data of the lidar to be tested 3 can be calculated. By calculating the deviation between the theoretical values ​​and the measured values ​​of the scan data of the lidar to be tested 3, the distance and angle accuracy can be obtained.

[0039] The measurement results of the lidar distance and angle testing methods are as follows: Figures 3-5 As shown, for ease of understanding, a top view is used as an example. Points O1 and O2 are the ranging centers of the lidar. Based on these, the coordinate system O1xy of the calibrated lidar and the coordinate system O2xy′ of the lidar under test are established. The distance between points O1 and O2 is d. x Point D is the selected measurement point on the target vehicle, point A is the position of point D projected onto the x-axis, point B is the position of point D projected onto the y-axis, and point C is the position of point D projected onto the y′-axis.

[0040] When point D is located between the two lidar sensors, from Figure 3 As can be seen from the given information, the coordinates of the set point D in the calibrated lidar coordinate system are (x1, y1, z1). Therefore, the theoretical coordinates of the set point D in the lidar coordinate system to be tested should be (-(d...). x Given the equations -|x1|, y1, z1), the true distance of point D relative to the lidar under test is... The true value of the horizontal angle is The true value of the vertical angle is

[0041] When point D is located to the left of the two lidar sensors, from Figure 4 As can be seen from the given information, the coordinates of the set point D in the calibrated lidar coordinate system are (x1, y1, z1). Therefore, the theoretical coordinates of the set point D in the lidar coordinate system to be tested should be (-(|x1|+d). x If y1, z1), then the true distance of point D relative to the lidar under test is y1, z1). The true value of the horizontal angle is The true value of the vertical angle is

[0042] When point D is located to the right of both lidar sensors, from Figure 5 As can be seen from the given information, the coordinates of the set point D in the calibrated lidar coordinate system are (x1, y1, z1). Therefore, the theoretical coordinates of the set point D in the lidar coordinate system to be tested should be (|x1| - d). x If the distance between point D and the LiDAR under test is (y1, z1), then the true distance is (y1, z1). The true value of the horizontal angle is The true value of the vertical angle is

[0043] Based on the above three scenarios, the distance and angle accuracy can be obtained by calculating the deviation between the theoretical and measured values ​​of the laser radar scanning data under test. The distance measurement value is the product of the laser beam's flight time t and the speed of light c divided by 2, and the angle measurement value is the horizontal and vertical angles when the laser beam is emitted.

[0044] It is worth noting that, by Figure 4 and Figure 5 It can be seen that fixing the two lidars horizontally relative to each other ensures the relative position between the two coordinate systems. There is no need to deliberately adjust the orientation angle of the test vehicle 1 or the target vehicle 4. As long as the target vehicle 4 is within the field of view of the two lidars, the acquisition of the true value will not be affected no matter how it moves.

[0045] It should be noted that the calibrated lidar, i.e. the reference device, can be calibrated by other methods, such as by a ground truth device based on differential positioning. The lidar to be tested can also be used as a reference device after verification. In addition, the calibrated lidar can be replaced with other high-precision devices with ranging and angle measurement capabilities, as long as the translation vector between the reference device and the lidar to be tested is ensured.

[0046] The dynamic testing method for lidar distance and angle of the present invention can ensure the acquisition of true values ​​in dynamic scenes without the use of additional equipment and motion platforms for obtaining true values.

[0047] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A dynamic testing method for lidar distance and angle, characterized in that, Includes the following steps: Step 1: Prepare test tools: two lidars, one test vehicle (1) and one target vehicle (4), wherein the two lidars are a calibrated lidar (2) and a lidar to be tested (3). Step 2: Deploy two lidar units: The two lidar units should be at the same height and horizontally spaced at a predetermined distance. It is horizontally fixed on the test vehicle (1); Step 3: Acquiring scanning data: During the movement of the test vehicle (1) and the target vehicle (4), the two lidars scan the target vehicle (4) to acquire their respective scanning data; Step 4: Calculate the theoretical value: Based on the scanning data and translation vector of the calibrated lidar (2), calculate the theoretical value of the scanning data of the lidar to be tested (3); Step 5: Obtain the distance and angle accuracy of the lidar: The distance and angle accuracy of the lidar under test (3) are obtained by calculating the deviation between the theoretical value and the measured value of the scanning data of the lidar under test (3); In step 2, the two lidars are placed horizontally relative to each other to ensure that there is no rotation between their coordinate systems, only translation along the x-axis, and the translation vector is... ,in, This is the preset horizontal spacing; In step 4, the coordinates of the measurement point of the target vehicle (4) in the coordinate system of the calibrated lidar (2) are set as follows: The theoretical coordinates of the measurement point of the target vehicle (4) in the coordinate system of the lidar under test (3) are: Since there is no rotation between the coordinate systems of the two lidar units, only translation along the x-axis, therefore, , ; In the fifth step, the distance and angle accuracy can be obtained by calculating the deviation between the theoretical value and the measured value of the scanning data of the laser radar (3) under test. The distance measurement value of the target vehicle (4) relative to the laser radar (3) under test is the product of the laser flight time t and the speed of light c divided by 2. The angle measurement value of the target vehicle (4) relative to the laser radar (3) under test is the horizontal angle and vertical angle when the laser beam is emitted.

2. The dynamic testing method for lidar distance and angle according to claim 1, characterized in that: When the measurement point of the target vehicle (4) is located between the two lidars, then Therefore, the theoretical distance between the measurement point of the target vehicle (4) and the lidar under test (3) is [value missing]. The theoretical horizontal angle value of the measurement point of the target vehicle (4) relative to the lidar under test (3) is... The theoretical vertical angle between the measurement point of the target vehicle (4) and the lidar under test (3) is then... .

3. The dynamic testing method for lidar distance and angle according to claim 1, characterized in that: When the measurement point of the target vehicle (4) is located to the left of the two lidars, then Therefore, the theoretical distance between the measurement point of the target vehicle (4) and the lidar under test (3) is [value missing]. The theoretical horizontal angle value of the measurement point of the target vehicle (4) relative to the lidar under test (3) is... The theoretical vertical angle between the measurement point of the target vehicle (4) and the lidar under test (3) is then... .

4. The dynamic testing method for lidar distance and angle according to claim 1, characterized in that: When the measurement point of the target vehicle (4) is located to the right of the two lidars, then Therefore, the theoretical distance between the measurement point of the target vehicle (4) and the lidar under test (3) is [value missing]. The theoretical horizontal angle value of the measurement point of the target vehicle (4) relative to the lidar under test (3) is... The theoretical vertical angle between the measurement point of the target vehicle (4) and the lidar under test (3) is then... .

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