Angle calibration device and method for lidar

Abstract

The present application relates to an angle calibration device and an angle calibration method for a lidar. The method includes: calibrating the horizontal center angle of the movement, the horizontal included angle between different movements, and the horizontal offset angle between different mirror surfaces of the rotating mirror according to the point cloud data detected by the movement of the lidar on the horizontal angle marking body and the horizontal angle marking background board; after completing the calibration of the horizontal angles of all the movements of the lidar, calibrating the vertical angles of different movements of the lidar according to the differences between the point clouds detected by different movements of the lidar on the vertical angle marking board under the same mirror surface of the rotating mirror, and calibrating the pitch angles of different mirror surfaces of the rotating mirror according to the differences between the point clouds detected by the same movement of the lidar on the vertical angle marking board under different mirror surfaces of the rotating mirror. Through the present application, the problem of high cost of the angle calibration method for lidar in the related art is solved.

Description

Technical Field

[0001] This application relates to the technical field of lidar, and particularly to an angle calibration device and an angle calibration method for lidar. Background Art

[0002] In related technologies, the angular deviation of lidar is mainly reduced by improving the manufacturing and processing accuracy of structural parts and the assembly accuracy, but this will result in very high manufacturing costs. There are also some related technologies that, under a fixed tooling, use a light card to display the light spot emitted by the laser, and then calculate the deviation between the theoretical value and the actual value of the lidar's movement mechanism, rotating mirror, etc. based on the offset angle of the light spot in different states; this calibration method not only faces the problem of poor reduction of the point cloud field of view in the real scene, but also has a complex calibration process and high labor costs, so it is not suitable for mass production. Summary of the Invention

[0003] The angle calibration device and the angle calibration method for lidar provided by the embodiments of the present invention at least solve the problem of high cost in the angle calibration method of lidar in related technologies.

[0004] An angle calibration device for lidar includes: a standard tooling table, a horizontal angle marking body, a horizontal angle marking background board, and a vertical angle marking board; wherein,

[0005] The extension direction Z-axis of the axis of the standard tooling table is perpendicular to the vertical angle marking board, and the standard tooling table is used to fix the lidar;

[0006] The extension direction Z-axis of the axis of the horizontal angle marking body is perpendicular to the vertical angle marking board, and the horizontal angle marking body includes a pair of sides parallel to the axis of the horizontal angle marking body;

[0007] The horizontal angle marking board is located behind the horizontal angle marking body relative to the standard tooling table, the plane X-Z plane of the horizontal angle marking background board is perpendicular to the plane X-Y plane of the vertical angle marking board, and is perpendicular to the plane Y-Z plane which is the common plane of the axis of the horizontal angle marking body and the axis of the standard tooling table;

[0008] The standard tooling table further includes a pitch angle adjustment mechanism for rotating the lidar within the plane Y-Z plane which is the common plane of the axis of the horizontal angle marking body and the axis of the standard tooling table.

[0009] In some of the embodiments, the distance between the standard tooling table and the horizontal angle marking body is 4 to 5 meters; the distance between the horizontal angle marking board and the horizontal angle marking body is 0.8 to 1.2 meters; the distance between the distal end of the vertical angle marking board and the standard tooling table is 10 to 15 meters.

[0010] In some of these embodiments, the device further includes an electronic device, which is configured to acquire the point cloud data detected by the lidar and calibrate the installation angle of the lidar, the installation angle of the movement, and the installation angle of the rotating mirror.

[0011] An angle calibration method for a lidar, which is applied to the above-mentioned angle calibration device. The angle calibration method includes:

[0012] According to the point cloud data detected by the movement of the lidar on the horizontal angle marking body and the horizontal angle marking background board, calibrate the horizontal center angle of the movement, the horizontal included angle between different movements, and the horizontal offset angle between different rotating mirror surfaces;

[0013] After completing the calibration of the horizontal angles of all the movements of the lidar, according to the differences between the point clouds detected by different movements of the lidar on the vertical angle marking board under the same rotating mirror surface, calibrate the vertical angles of different movements of the lidar, and according to the differences between the point clouds detected by the same movement of the lidar on the vertical angle marking board under different rotating mirror surfaces, calibrate the pitch angles of different rotating mirror surfaces.

[0014] Calibrating the horizontal center angle of the movement according to the point cloud data detected by the movement of the lidar on the horizontal angle marking body and the horizontal angle marking background board includes:

[0015] Obtain the ranging values of multiple point cloud columns with a horizontal angle of 90°±α detected by the movement of the lidar under the same rotating mirror surface, where α is not less than the maximum value of the design deviation;

[0016] Determine a specific point cloud column according to the ranging values of each point cloud in the point cloud column, and record the initial horizontal angle value corresponding to the specific point cloud column. The specific point cloud column includes one of the following: some point clouds in the specific point cloud column are on the horizontal angle marking body, and the other part of the point clouds are on the horizontal angle marking background board; all the point clouds in the specific point cloud column are on the horizontal angle marking body, and all the point clouds in the point cloud column adjacent to the specific point cloud column are on the horizontal angle marking background board;

[0017] Determine the horizontal angle correction amount of the point cloud of the first movement according to the difference between the initial horizontal angle value and 90°.

[0018] In some of these embodiments, the method further includes:

[0019] Correct the horizontal angle of the movement multiple times until the absolute value of the horizontal angle correction amount is less than the set threshold.

[0020] In some of these embodiments, calibrating the horizontal angle between different cores based on the point cloud data detected by the cores of the lidar on the horizontal angle marking body and the horizontal angle marking background board includes:

[0021] Obtain the horizontal coordinates of the point cloud columns on the horizontal angle marking body detected by the first core and the second core of the lidar under the same rotating mirror surface;

[0022] Obtain the first light emission angle correction value of the second core, and the first light emission angle correction value makes the horizontal coordinates of the point cloud columns corresponding to the same horizontal angle detected by the first core and the second core coincide.

[0023] In some of these embodiments, calibrating the horizontal angle between different cores based on the point cloud data detected by the cores of the lidar on the horizontal angle marking body and the horizontal angle marking background board further includes:

[0024] Obtain the horizontal coordinates of the point cloud columns on the horizontal angle marking background board detected by the first core or the second core of the lidar under the same rotating mirror surface;

[0025] Obtain the second light emission angle correction value of the first core and the second core, and the second light emission angle correction value makes the sum of the maximum horizontal coordinate value and the minimum horizontal coordinate value of the point cloud column detected by the first core or the second core on the horizontal angle marking background board zero, where the horizontal coordinate value of the axis of the horizontal angle marking background board is zero.

[0026] In some of these embodiments, calibrating the horizontal offset angle between different rotating mirror surfaces based on the point cloud data detected by the cores of the lidar on the horizontal angle marking body and the horizontal angle marking background board includes:

[0027] Obtain the horizontal coordinates of the point cloud columns on the horizontal angle marking background board detected by the same core of the lidar under the first rotating mirror surface and the second rotating mirror surface, and calculate the mean value of the horizontal coordinates of the point cloud column corresponding to the first rotating mirror surface and the mean value of the horizontal coordinates of the point cloud column corresponding to the second rotating mirror surface respectively;

[0028] Obtain the horizontal offset angle correction value of the second rotating mirror surface, and the horizontal offset angle correction value makes the mean difference of the horizontal coordinates of the point cloud columns corresponding to the first rotating mirror surface and the second rotating mirror surface less than a preset threshold.

[0029] In some of these embodiments, calibrating the vertical angles of different cores of the lidar based on the differences between the point clouds detected by different cores of the lidar under the same rotating mirror surface includes:

[0030] Obtain the height coordinates of the point clouds located on the vertical angle marking board detected by the first movement and the second movement of the lidar under the same rotating mirror surface, and calculate the mean value of the height coordinates of the point clouds corresponding to the first movement and the mean value of the height coordinates of the point clouds corresponding to the second movement respectively;

[0031] Obtain the first pitch angle correction value of the second movement, and the first pitch angle correction value makes the mean difference of the height coordinates of the point clouds corresponding to the first movement and the second movement less than a preset threshold.

[0032] In some embodiments, calibrating the vertical angles of different movements of the lidar according to the differences between the point clouds detected by different movements of the lidar under the same rotating mirror surface further includes:

[0033] Obtain the height coordinates of the point clouds located on the vertical angle marking board detected by the first movement or the second movement of the lidar under the same rotating mirror surface, and calculate the extreme difference of the height coordinates of the point clouds corresponding to the first movement or the extreme difference of the height coordinates of the point clouds corresponding to the second movement;

[0034] Obtain the second pitch angle correction values of the first movement and the second movement, and the second pitch angle correction values make the extreme difference of the height coordinates of the point clouds corresponding to the first movement or the extreme difference of the height coordinates of the point clouds corresponding to the second movement less than a preset threshold.

[0035] In some embodiments, calibrating the pitch angles of different rotating mirror surfaces according to the differences between the point clouds located on the vertical angle marking board detected by the same movement of the lidar under different rotating mirror surfaces includes:

[0036] Obtain the height coordinates of the point clouds located on the vertical angle marking board detected by the same movement of the lidar under the first rotating mirror surface and the second rotating mirror surface, and calculate the mean value of the height coordinates of the point clouds corresponding to the first rotating mirror surface and the mean value of the height coordinates of the point clouds corresponding to the second rotating mirror surface respectively;

[0037] Obtain the pitch angle correction value of the second rotating mirror surface, and the pitch angle correction value makes the mean difference of the height coordinates of the point clouds corresponding to the first rotating mirror surface and the second rotating mirror surface less than a preset threshold.

[0038] In some embodiments, before calibrating the vertical angles of different movements of the lidar according to the differences between the point clouds located on the vertical angle marking board detected by different movements of the lidar under the same rotating mirror surface, and calibrating the pitch angles of different rotating mirror surfaces according to the differences between the point clouds located on the vertical angle marking board detected by the same movement of the lidar under different rotating mirror surfaces, the method further includes:

[0039] Adjust the pitch angle adjustment mechanism so that the vertical field of view angle of the lidar is fully presented on the vertical angle indicator board.

[0040] An electronic device includes: a processor, and a memory storing a program, where the program includes instructions that, when executed by the processor, cause the processor to execute the above method.

[0041] A non-transitory machine-readable medium storing computer instructions for causing a computer to execute the above method.

[0042] The lidar angle calibration device and method provided by the embodiments of the present invention calibrate the horizontal center angle of the movement, the horizontal included angle between different movements, and the horizontal offset angle between different rotating mirror surfaces according to the point cloud data detected by the movement of the lidar on the horizontal angle marking body and the horizontal angle marking background board; after calibrating the horizontal angles of all movements of the lidar, according to the differences between the point clouds detected by different movements of the lidar on the vertical angle indicator board under the same rotating mirror surface, calibrate the vertical angles of different movements of the lidar, and according to the differences between the point clouds detected by the same movement of the lidar on the vertical angle indicator board under different rotating mirror surfaces, calibrate the pitch angles of different rotating mirror surfaces, thus solving the problem of high cost of the lidar angle calibration method in the related art and providing a lidar angle calibration method suitable for mass production.

[0043] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects, and advantages of the present invention more concise and understandable. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following briefly introduces the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention, and those of ordinary skill in the art can obtain other embodiments according to these drawings without creative efforts.

[0045] Figure 1 is the front view of the lidar angle calibration device of this embodiment.

[0046] Figure 2 is the side view of the lidar angle calibration device of this embodiment.

[0047] Figure 3 is the flowchart of the lidar angle calibration method of this embodiment.

[0048] Figure 4It is a schematic diagram of the 45° projection of the point cloud detected by the lidar during the angle calibration of this embodiment.

[0049] Figure 5 It is a flowchart for calibrating the central angle of each movement mechanism in this embodiment.

[0050] Figure 6 It is a schematic diagram of a specific point cloud column in this embodiment.

[0051] Figure 7 It is the process of calibrating the horizontal included angle between movement mechanisms in this embodiment Figure 1 。

[0052] Figure 8 It is the process of calibrating the horizontal included angle between movement mechanisms in this embodiment Figure 2 。

[0053] Figure 9 It is a flowchart for calibrating the horizontal angle of each mirror surface in this embodiment.

[0054] Figure 10 It is a schematic diagram of the structure of the electronic device in this embodiment. Detailed implementation manners

[0055] The embodiments of this embodiment will be described in more detail below with reference to the accompanying drawings. Although some embodiments of this embodiment are shown in the drawings, it should be understood that this embodiment can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand this embodiment. It should be understood that the drawings and embodiments of this embodiment are only for exemplary purposes and are not used to limit the protection scope of this embodiment.

[0056] Term explanation

[0057] Angle calibration: Provide real angle information for the analytical formula of the point cloud. The 3D lidar calculates the distance through the flight time and the speed of light of the laser, provides the horizontal angle information through the encoder scale line, and provides the vertical angle information by the installation position of the laser board (the circuit board that drives the laser to emit light, which determines the initial position of the laser), the installation position of the movement mechanism, and the pitch angle of the rotating mirror. Due to manufacturing process limitations, there are deviations between the theoretical angle values of the analytical space coordinate system and the actual angles, resulting in blurred or incorrect deviations of objects in the real physical scene. Angle calibration is used to compensate for the deviation angles.

[0058] Radar field of view: That is, the range covered by a frame of point cloud of the radar, which is described by the horizontal coverage angle and the vertical coverage angle based on the physical origin of the radar. The methods to increase the radar field of view include increasing the number of lasers (increasing the angle covered by the light-emitting area), increasing the number of cores (two cores are responsible for different detection areas respectively), and increasing the number of rotating mirrors (increasing the vertical field of view angle of the radar by the pitch angle of the rotating mirror).

[0059] Calibration mirror: In order for the laser to obtain a larger field of view and denser point cloud, multiple rotating mirrors are used to achieve the multiplication of point cloud. Generally, the angle calibration is completed using the data of one of the mirrors, and the selected calibration mirror has more precise dimension control in mechanical design.

[0060] In order to achieve the angle calibration of the lidar, this embodiment provides an angle calibration device for the lidar. Figure 1 is the front view of the angle calibration device of the lidar in this embodiment; Figure 2 is the side view of the angle calibration device of the lidar in this embodiment. As Figure 1 and Figure 2 shown, the angle calibration device includes: a standard tooling table 10, a horizontal angle marking body 20, a horizontal angle marking background board 30, and a vertical angle marking board 40; among them,

[0061] The extension direction Z-axis of the axis of the standard tooling table 10 is perpendicular to the vertical angle marking board 40, and the standard tooling table 10 is used to fix the lidar.

[0062] The extension direction Z-axis of the axis of the horizontal angle marking body 20 is perpendicular to the vertical angle marking board 40, and the horizontal angle marking body 20 includes a pair of sides parallel to the axis of the horizontal angle marking body 20.

[0063] The horizontal angle marking board is located behind the horizontal angle marking body 20 relative to the standard tooling table 10. The plane X-Z plane of the horizontal angle marking background board 30 is perpendicular to the plane X-Y plane of the vertical angle marking board 40, and perpendicular to the plane Y-Z plane which is the common plane of the axis of the horizontal angle marking body 20 and the axis of the standard tooling table 10.

[0064] The standard tooling table 10 further includes a pitch angle adjustment mechanism (not shown in the figure) for rotating the lidar in the plane Y-Z plane which is the common plane of the axis of the horizontal angle marking body 20 and the axis of the standard tooling table 10.

[0065] The lidar 50 to be calibrated is fixed at the top of the standard tooling table 10, and its pitch angle can be adjusted by the pitch angle adjustment mechanism.

[0066] In some of these embodiments, the distance between the standard tooling table 10 and the horizontal angle marking body 20 is 4 to 5 meters; the distance between the horizontal angle marking board and the horizontal angle marking body 20 is 0.8 to 1.2 meters; the distance between the distal end of the vertical angle marking board 40 and the standard tooling table 10 is 10 to 15 meters.

[0067] In some of these embodiments, the device further includes an electronic device, which is used to acquire the point cloud data detected by the lidar, and calibrate the installation angle of the lidar, the installation angle of the movement, and the installation angle of the rotating mirror.

[0068] Specifically, the above computing device is used to implement the angle calibration method of the lidar.

[0069] Figure 3 is a flowchart of the angle calibration method of the lidar in this embodiment, which is applied to the above-mentioned lidar angle calibration device. The method includes the following processes:

[0070] Step S301: According to the point cloud data detected by the movement of the lidar on the horizontal angle marking body 20 and the horizontal angle marking background board 30, calibrate the horizontal center angle of the movement, the horizontal included angle between different movements, and the horizontal offset angle between different rotating mirror surfaces.

[0071] Step S302: After completing the calibration of the horizontal angles of all the movements of the lidar, according to the differences between the point clouds detected by different movements of the lidar on the vertical angle marking board 40 under the same rotating mirror surface, calibrate the vertical angles of different movements of the lidar, and according to the differences between the point clouds detected by the same movement of the lidar on the vertical angle marking board 40 under different rotating mirror surfaces, calibrate the pitch angles of different rotating mirror surfaces.

[0072] The angle calibration method provided by the above steps, on the one hand, uses the point cloud of the angle calibration device detected by the lidar for angle calibration without the need to rely on expensive equipment such as a display card, and on the other hand, calibrates the horizontal angle and the vertical angle separately during angle calibration, reducing the complexity of calibration.

[0073] The point cloud detected by the lidar is a three-dimensional point cloud. In this embodiment, the X-Y-Z axis coordinate system is used to represent the space of the point cloud, where the X axis represents the horizontal direction, the Z axis represents the height direction, and the Y axis is parallel to the X axis and the Z axis respectively. To simplify the calculation, the center point of the lidar is defined as the origin of the coordinate system.

[0074] Figure 4 is a schematic diagram of the 45° projection of the point cloud detected by the lidar during angle calibration in this embodiment, Figure 4The point cloud shown is the point cloud seen when the human eye looks down at the three-dimensional point cloud at an angle of 45° to the horizontal plane. Among them, the rectangular point cloud near the upper center of the picture represents the point cloud corresponding to the horizontal angle marking background board 30, the strip-shaped point cloud in front of it represents the point cloud corresponding to the horizontal angle marking body 10, and the reticular point clouds on both sides of the rectangular point cloud represent the point clouds corresponding to the vertical angle marking board 40.

[0075] The angle calibration method provided in this embodiment first calibrates the horizontal angle and then calibrates the vertical angle. The calibration objects include the position of the lidar, the positions of each movement, and the position of the rotating mirror surface. More specifically, the angle calibration of the lidar includes the following five parts, namely: A. Calibration of the central angle of each movement; B. Calibration of the horizontal included angle between movements; C. Calibration of the horizontal angle of each mirror surface; D. Calibration of the vertical included angle between movements; E. Calibration of the pitch angle of each rotating mirror surface. When calibrating, the calibration is carried out one by one in the order of ABCDEF, and finally the calibration of the horizontal central angle of the lidar movement, the horizontal included angle between different movements, the horizontal offset angle between different rotating mirror surfaces, the vertical angle of different movements, and the pitch angle of different rotating mirror surfaces is realized.

[0076] The following will describe each calibration process separately.

[0077] A. Calibration of the central angle of each movement

[0078] Obtain the ranging values of multiple point cloud columns with a horizontal angle of 90°±α detected by the movement of the lidar under the same rotating mirror surface, where α is not less than the maximum value of the design deviation; determine a specific point cloud column according to the ranging values of each point cloud in the point cloud column, and record the initial horizontal angle value corresponding to the specific point cloud column, where the specific point cloud column includes one of the following: part of the point clouds in the specific point cloud column are on the horizontal angle marking body 20, and the other part of the point clouds are on the horizontal angle marking background board 30; all the point clouds in the specific point cloud column are on the horizontal angle marking body 20, and all the point clouds in the point cloud column adjacent to the specific point cloud column are on the horizontal angle marking background board 30; determine the horizontal angle correction amount of the point cloud of the first movement according to the difference between the initial horizontal angle value and 90°.

[0079] The above maximum value of the design deviation refers to the sum of the horizontal offset angle of the mechanical design movement and the maximum error angle of the code disk for measuring angle information. If α is less than the maximum value of the design deviation, a specific point cloud column that meets the conditions may not be found in the obtained point clouds; if α is too large, the amount of calculation may increase. The value range of α can be 5° to 10°. In addition, since the direct correction of the cumulative error is adopted in this embodiment, there is no need to separately correct the measuring devices such as the code disk of the lidar, thus simplifying the calibration steps.

[0080] Figure 5 This is the flowchart for calibrating the central angle of each movement in this embodiment. As Figure 5 shown, based on the selected point cloud information, using the ranging values of each column of point clouds (Method 1: There is a part of the ranging value of a column of point clouds on the horizontal angle marker and a part on the horizontal angle marker background board; Method 2: Comparing the point cloud data of the front and rear columns, there is a ranging value of the front column of point clouds on the horizontal angle marker background board, and a specific column of point clouds on the horizontal angle marker, as Figure 6 shown), judge the point cloud angle information on the horizontal angle marker, and record this angle information. Calculate the correction amount and correction value based on the recorded angle information and the 90-degree difference. The correction value is the accumulation of each correction amount (the correction value is written into the offset of the radar at the fixed origin). The correction amount is the difference between each recorded angle information and 90 degrees. The correction value is the calibration value applied to the analytical formula of the point cloud.

[0081] In some of these embodiments, a small-step and multiple-time method is adopted to correct the horizontal angle of the movement multiple times until the absolute value of the horizontal angle correction amount is less than the set threshold. Continuing to refer to Figure 5 , judge whether the central angle calibration is completed based on the correction amount. When the correction amount is less than a certain threshold (this threshold is less than the horizontal angle resolution of the radar), the angle calibration is completed. When it is greater than the threshold, write the correction value into the radar and apply it to the analytical formula for calibration repeatedly.

[0082] B. Calibration of the horizontal included angle between movements

[0083] Obtain the horizontal coordinates of the point cloud columns on the horizontal angle marker 20 detected by the first movement and the second movement of the lidar under the same rotating mirror surface; obtain the first light emission angle correction value of the second movement, and the first light emission angle correction value makes the horizontal coordinates of the corresponding point cloud columns detected by the first movement and the second movement coincide at the same horizontal angle.

[0084] Each movement has a light emission angle, and the included angle of the light emission angles represents the included angle between the movements.

[0085] Figure 7 This is the process for calibrating the horizontal included angle between movements in this embodiment Figure 1 , as Figure 7 shown, based on the movement information, mirror information, horizontal angle information, and distance information in the point cloud protocol, screen the point cloud information on the horizontal angle marker, calculate the coincidence degree of the point clouds on the horizontal angle marker under the same mirror of different movements, and make the point clouds of the two movements coincide on the horizontal angle marker by setting the light emission angle of one of the movements (rotating the point cloud as a whole).

[0086] In some of these embodiments, calibrating the horizontal angle between different movement units based on the point cloud data detected by the movement unit of the lidar on the horizontal angle marking body 20 and the horizontal angle marking background board 30 further includes: obtaining the horizontal coordinates of the point cloud columns detected by the first movement unit or the second movement unit of the lidar on the horizontal angle marking background board 30 under the same rotating mirror surface; obtaining the second light emission angle correction values of the first movement unit and the second movement unit, where the second light emission angle correction values make the sum of the maximum horizontal coordinate value and the minimum horizontal coordinate value of the point cloud columns detected by the first movement unit or the second movement unit on the horizontal angle marking background board 30 equal to zero, and the horizontal coordinate value of the axis of the horizontal angle marking background board 30 is zero.

[0087] Figure 8 This is the process of calibrating the horizontal angle between movement units in this embodiment Figure 2 , such as Figure 8 As shown, after the horizontal coordinates of the point cloud columns corresponding to the same horizontal angle detected by the first movement unit and the second movement unit coincide, the deviation of the horizontal coordinates of the point cloud caused by the angle deviation between the movement units is eliminated. However, the deviation of the lidar in the horizontal angle is not eliminated. Therefore, the overall rotation of the horizontal angle of all movement units is continued. Filter the point cloud information on the horizontal angle marking background board according to the movement unit information, mirror surface information, horizontal angle information, and distance information in the point cloud protocol, calculate the sum of the maximum value and the minimum value of the X value of the point cloud on the horizontal angle marking background board, synchronously correct the light emission angles of the left and right movement units, so that the sum of the extreme values is within the range near 0, and the correction value is used as the calibration value for the point cloud analysis formula.

[0088] C. Calibration of the horizontal angle of each mirror surface

[0089] Obtain the horizontal coordinates of the point cloud columns detected by the same movement unit of the lidar on the horizontal angle marking background board 30 under the first rotating mirror surface and the second rotating mirror surface, and calculate the mean value of the horizontal coordinates of the point cloud column corresponding to the first rotating mirror surface and the mean value of the horizontal coordinates of the point cloud column corresponding to the second rotating mirror surface respectively; obtain the horizontal offset angle correction value of the second rotating mirror surface, where the horizontal offset angle correction value makes the mean difference of the horizontal coordinates of the point cloud columns corresponding to the first rotating mirror surface and the second rotating mirror surface less than a preset threshold.

[0090] Figure 9 This is the flowchart of calibrating the horizontal angle of each mirror surface in this embodiment. As Figure 9 shown, filter the point cloud data of each mirror surface on the horizontal angle marking body according to the movement unit information, mirror surface information, and distance information, and complete the horizontal offset angle calibration of other mirror surfaces by using the difference between the mean value of the X value of other mirror surfaces and the calibrated mirror surface.

[0091] D. Calibration of the vertical angle between movement units

[0092] Obtain the height coordinates of the point clouds located on the vertical angle marking board 40 detected by the first movement and the second movement of the lidar under the same rotating mirror surface, and calculate the mean value of the height coordinates of the point clouds corresponding to the first movement and the mean value of the height coordinates of the point clouds corresponding to the second movement respectively; obtain the first pitch angle correction value of the second movement, and the first pitch angle correction value makes the mean difference of the height coordinates of the point clouds corresponding to the first movement and the second movement less than a preset threshold.

[0093] In this embodiment, adjust the pitch angle of the radar to completely cover the vertical field of view angle of the radar in the ground calibration area, filter the ground data of the fixed horizontal angles of the calibration mirrors of each movement, calculate the mean value of the Z values of the point cloud data, and use the mean difference of each movement to adjust the pitch angle of one movement to achieve the coincidence of the point clouds of the two movements.

[0094] Similar to adjusting the horizontal angle between the movements, after the height coordinates of the corresponding point clouds detected by the first movement and the second movement coincide, the deviation of the height coordinates of the point clouds caused by the pitch angle deviation between the movements is eliminated, but the deviation of the lidar in the vertical angle is not eliminated. Therefore, continue to perform an overall rotation of the pitch angle for all movements. Obtain the height coordinates of the point clouds located on the vertical angle marking board 40 detected by the first movement or the second movement of the lidar under the same rotating mirror surface, and calculate the extreme difference of the height coordinates of the point clouds corresponding to the first movement or the extreme difference of the height coordinates of the point clouds corresponding to the second movement; obtain the second pitch angle correction value of the first movement and the second movement, and the second pitch angle correction value makes the extreme difference of the height coordinates of the point clouds corresponding to the first movement or the extreme difference of the height coordinates of the point clouds corresponding to the second movement less than a preset threshold.

[0095] E. Calibration of the pitch angle of each rotating mirror surface.

[0096] Obtain the height coordinates of the point clouds located on the vertical angle marking board 40 detected by the same movement of the lidar under the first rotating mirror surface and the second rotating mirror surface, and calculate the mean value of the height coordinates of the point clouds corresponding to the first rotating mirror surface and the mean value of the height coordinates of the point clouds corresponding to the second rotating mirror surface respectively; obtain the pitch angle correction value of the second rotating mirror surface, and the pitch angle correction value makes the mean difference of the height coordinates of the point clouds corresponding to the first rotating mirror surface and the second rotating mirror surface less than a preset threshold.

[0097] Adjust the pitch angle of the radar to completely cover the vertical field of view angle of the radar on the vertical angle marking board, filter the point cloud data of each mirror surface of a single movement on the vertical angle marking board, and use the mean value of the Z values of the point clouds of each mirror surface to coincide the non-calibration mirror surface and the calibration mirror surface.

[0098] In some of these embodiments, before performing the calibration of the vertical angle, the method further includes: adjusting the pitch angle adjustment mechanism so that the vertical field of view angle of the lidar is completely presented on the vertical angle marking board 40.

[0099] An embodiment of the present invention also provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the embodiment of the present invention.

[0100] An embodiment of the present invention also provides an electronic device, including: at least one processor; and a memory communicatively connected to the at least one processor. The memory stores a computer program executable by the at least one processor, and the computer program, when executed by the at least one processor, is used to cause the electronic device to execute the method of the embodiment of the present invention.

[0101] Reference Figure 10 , a block diagram of an electronic device that can be a server or a client as an embodiment of the present invention will now be described. It is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as, a laptop computer, a desktop computer, a workbench, a personal digital assistant, a server, a blade server, a mainframe computer, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as, a personal digital processor, a cellular phone, a smart phone, a wearable device, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or claimed herein.

[0102] As Figure 10 shown, the electronic device includes a computing unit 1001, which can execute various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 1002 or a computer program loaded from a storage unit 1008 into a random access memory (RAM) 1003. In the RAM 1003, various programs and data required for the operation of the electronic device can also be stored. The computing unit 1001, the ROM 1002, and the RAM 1003 are connected to each other through a bus 1004. An input / output (I / O) interface 1005 is also connected to the bus 1004.

[0103] Multiple components in the electronic device are connected to the I / O interface 1005, including: an input unit 1006, an output unit 1007, a storage unit 1008, and a communication unit 1009. The input unit 1006 can be any type of device capable of inputting information into the electronic device. The input unit 1006 can receive input digital or character information and generate key signal inputs related to the user settings and / or function controls of the electronic device. The output unit 1007 can be any type of device capable of presenting information and can include, but is not limited to, a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 1008 can include, but is not limited to, magnetic disks and optical discs. The communication unit 1009 allows the electronic device to exchange information / data with other devices via a computer network such as the Internet and / or various telecommunication networks and can include, but is not limited to, a modem, a network card, an infrared communication device, and / or a wireless communication transceiver, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0104] The computing unit 1001 can be various general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of the computing unit 1001 include, but are not limited to, a CPU, a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing units, various computing units running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. The computing unit 1001 executes the various methods and processes described above. For example, in some embodiments, the method embodiments of the present invention can be implemented as a computer program tangibly contained in a machine-readable medium, such as the storage unit 1008. In some embodiments, part or all of the computer program can be loaded and / or installed onto the electronic device via the ROM 1002 and / or the communication unit 1009. In some embodiments, the computing unit 1001 can be configured to execute the above-described method by any other suitable means (e.g., by means of firmware).

[0105] The computer program for implementing the method of the embodiments of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to the processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when the computer program is executed by the processor or controller, the functions / operations specified in the flowchart and / or block diagram are implemented. The computer program can be executed entirely on the machine, partially on the machine, executed partially on the machine and partially on a remote machine as an independent software package, or executed entirely on a remote machine or server.

[0106] In the context of embodiments of the present inventive concept, a machine-readable medium may be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, or infrared system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of a machine-readable storage medium would include an electrical connection based on one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0107] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open-ended, that is, "including but not limited to". The term "based on" means "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "a plurality" mentioned in the embodiments of the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless clearly specified otherwise in the context, it should be understood as "one or more".

[0108] In the method embodiments provided by the embodiments of the present invention, the steps recorded in the method embodiments may be executed in different orders and / or executed in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The protection scope of the present invention is not limited in this regard.

[0109] The term "embodiment" in this specification means that the specific features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment of the present invention. The phrase appears in various positions in the specification and does not necessarily mean the same embodiment, nor does it mean being independent or alternative to other embodiments and mutually exclusive. The embodiments in this specification are all described in a related manner, and the same or similar parts among the embodiments are referred to each other. In particular, for device, apparatus, and system embodiments, since they are basically similar to method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiments.

[0110] The above-described embodiments merely represent several implementation manners of the present invention. The description thereof is relatively specific and detailed, but it should not be construed as a limitation on the scope of patent protection. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the appended claims.

Claims

1. An angle calibration device for a laser radar, comprising: Standard workbench, horizontal angle marking body, horizontal angle marking background board, vertical angle marking board; among them, The extension direction of the axis of the standard tooling table is perpendicular to the vertical angle marking plate, and the standard tooling table is used to fix the laser radar; The extending direction of the axis of the horizontal angle marking body is perpendicular to the vertical angle marking plate, and the horizontal angle marking body includes a pair of side edges parallel to the axis of the horizontal angle marking body; The horizontal angle marking background plate is located behind the horizontal angle marking body relative to the standard tooling table, and the plane where the horizontal angle marking background plate is located is perpendicular to the plane where the vertical angle marking plate is located, and is perpendicular to the common plane of the axis of the horizontal angle marking body and the axis of the standard tooling table; The standard tooling platform also includes a pitch angle adjustment mechanism that enables the laser radar to rotate within a common plane of the axis of the horizontal angle marking body and the axis of the standard tooling platform.

2. The device according to claim 1, characterized in that The distance between the standard tooling platform and the horizontal angle marking body is 4 to 5 meters; the distance between the horizontal angle marking background plate and the horizontal angle marking body is 0.8 to 1.2 meters; the distance between the far end of the vertical angle marking plate and the standard tooling platform is 10 to 15 meters.

3. The device according to claim 1, characterized in that The device also includes an electronic device, which is used to obtain point cloud data detected by the laser radar and calibrate the installation angle of the laser radar, the installation angle of the movement, and the installation angle of the rotating mirror.

4. A laser radar angle calibration method, applied to the angle calibration device according to any one of claims 1 to 3, characterized in that: The angle calibration method comprises: According to the data of the point cloud located on the horizontal angle marking body and the horizontal angle marking background plate detected by the laser radar movement, the horizontal center angle of the movement, the horizontal angles between different movements, and the horizontal offset angles between different rotating mirror surfaces are calibrated; After completing the calibration of the horizontal angles of all the laser radar's movements, the vertical angles of different movements of the laser radar are calibrated according to the differences between the point clouds located on the vertical angle marking plate detected by different movements of the laser radar under the same rotating mirror surface, and the pitch angles of different rotating mirror surfaces are calibrated according to the differences between the point clouds located on the vertical angle marking plate detected by the same movement of the laser radar under different rotating mirror surfaces.

5. According to the angle calibration method of claim 4, calibrating the horizontal center angle of the core according to the point cloud data located on the horizontal angle marking body and the horizontal angle marking background plate detected by the core of the laser radar comprises: Obtaining the ranging values ​​of multiple point cloud columns with a horizontal angle of 90°±α detected by the core of the laser radar under the same rotating mirror surface, wherein α is not less than the maximum value of the designed deviation; Determine a specific point cloud column according to the distance measurement value of each point cloud in the point cloud column, and record the initial horizontal angle value corresponding to the specific point cloud column, wherein the specific point cloud column includes one of the following: a part of the point clouds in the specific point cloud column are on the horizontal angle marking body, and another part of the point clouds are on the horizontal angle marking background board; all the point clouds in the specific point cloud column are on the horizontal angle marking body, and all the point clouds in the point cloud column adjacent to the specific point cloud column are on the horizontal angle marking background board; The horizontal angle correction amount of the point cloud of the movement is determined according to the difference between the initial horizontal angle value and 90°.

6. The angle calibration method according to claim 5, characterized in that: The method further comprises: The horizontal angle of the movement is corrected multiple times until the absolute value of the horizontal angle correction amount is less than a set threshold.

7. The angle calibration method according to claim 4, characterized in that: According to the point cloud data located on the horizontal angle marking body and the horizontal angle marking background plate detected by the laser radar movement, calibrating the horizontal angles between different movements includes: Acquire the horizontal coordinates of the point cloud column located on the horizontal angle marking body detected by the first movement and the second movement of the laser radar under the same rotating mirror surface; A first luminous angle correction value of the second movement is obtained, wherein the first luminous angle correction value makes the horizontal coordinates of the point cloud columns corresponding to the same horizontal angle detected by the first movement and the second movement coincide with each other.

8. The angle calibration method according to claim 7, characterized in that: According to the point cloud data located on the horizontal angle marking body and the horizontal angle marking background plate detected by the laser radar movement, calibrating the horizontal angles between different movements also includes: Obtaining the horizontal coordinates of the point cloud column located on the horizontal angle marking background plate detected by the first movement or the second movement of the laser radar under the same rotating mirror surface; Obtain a second luminous angle correction value of the first movement and the second movement, wherein the second luminous angle correction value makes the sum of the maximum horizontal coordinate value and the minimum horizontal coordinate value of the point cloud column detected by the first movement or the second movement on the horizontal angle marking background plate be zero, wherein the horizontal coordinate value of the axis of the horizontal angle marking background plate is zero.

9. The angle calibration method according to claim 4, characterized in that: According to the point cloud data located on the horizontal angle marking body and the horizontal angle marking background plate detected by the laser radar core, calibrating the horizontal offset angle between different rotating mirror surfaces includes: Obtaining the horizontal coordinates of the point cloud column located on the horizontal angle marking background plate detected by the same movement of the laser radar under the first rotating mirror surface and the second rotating mirror surface, and calculating the mean value of the horizontal coordinates of the point cloud column corresponding to the first rotating mirror surface and the mean value of the horizontal coordinates of the point cloud column corresponding to the second rotating mirror surface respectively; A horizontal offset angle correction value of the second rotating mirror surface is obtained, wherein the horizontal offset angle correction value makes the mean difference of horizontal coordinates of the point cloud columns corresponding to the first rotating mirror surface and the second rotating mirror surface less than a preset threshold.

10. The angle calibration method according to claim 4, characterized in that: According to the difference between the point clouds detected by the different cores of the laser radar under the same rotating mirror surface, calibrating the vertical angles of the different cores of the laser radar includes: Obtaining the height coordinates of the point cloud located on the vertical angle marking plate detected by the first movement and the second movement of the laser radar under the same rotating mirror surface, and respectively calculating the mean value of the height coordinates of the point cloud corresponding to the first movement and the mean value of the height coordinates of the point cloud corresponding to the second movement; A first pitch angle correction value of the second movement is obtained, where the first pitch angle correction value makes the mean difference of height coordinates of the point clouds corresponding to the first movement and the second movement smaller than a preset threshold.

11. The angle calibration method according to claim 9, characterized in that: According to the difference between the point clouds detected by the different cores of the laser radar under the same rotating mirror surface, calibrating the vertical angles of the different cores of the laser radar also includes: Obtaining the height coordinates of the point cloud located on the vertical angle marking plate detected by the first movement or the second movement of the laser radar under the same rotating mirror surface, and calculating the extreme value difference of the height coordinates of the point cloud corresponding to the first movement or the extreme value difference of the height coordinates of the point cloud corresponding to the second movement; A second pitch angle correction value of the first movement and the second movement is obtained, wherein the second pitch angle correction value makes the extreme value difference of the height coordinate of the point cloud corresponding to the first movement or the extreme value difference of the height coordinate of the point cloud corresponding to the second movement smaller than a preset threshold.

12. The angle calibration method according to claim 4, characterized in that: According to the difference between the point clouds located on the vertical angle marking plate detected by the same core of the laser radar under different rotating mirror surfaces, calibrating the pitch angles of different rotating mirror surfaces includes: Obtaining the height coordinates of the point cloud located on the vertical angle marking plate detected by the same movement of the laser radar under the first rotating mirror surface and the second rotating mirror surface, and respectively calculating the average value of the height coordinates of the point cloud corresponding to the first rotating mirror surface and the average value of the height coordinates of the point cloud corresponding to the second rotating mirror surface; A pitch angle correction value of the second rotating mirror surface is obtained, wherein the pitch angle correction value makes the mean difference of height coordinates of corresponding point clouds of the first rotating mirror surface and the second rotating mirror surface less than a preset threshold.

13. The angle calibration method according to any one of claims 10 to 12, characterized in that: Before calibrating the vertical angles of different laser radars according to the difference between the point clouds located on the vertical angle marking plate detected by different laser radars under the same rotating mirror surface, and before calibrating the pitch angles of different rotating mirror surfaces according to the difference between the point clouds located on the vertical angle marking plate detected by the same laser radar under different rotating mirror surfaces, the method further includes: The pitch angle adjustment mechanism is adjusted so that the vertical angle of view of the laser radar is fully presented on the vertical angle marking plate.

14. An electronic device comprising: A processor, and a memory storing a program, wherein the program comprises instructions, which, when executed by the processor, cause the processor to perform the method according to any one of claims 4 to 13.

15. A non-transitory machine-readable medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer to execute the method according to any one of claims 4 to 13.

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