Laser radar lens distortion calibration method and device, medium and computer equipment

Abstract

The invention discloses a laser radar lens distortion calibration method and device, a storage medium and computer equipment, and relates to the technical field of laser radars. The method comprises the following steps: determining a theoretical position range of each light spot projection of an optical module according to an initial lens distortion parameter and an initial distortion center principal point; determining a new lens distortion parameter or a new distortion center principal point of the optical module according to the actual position information and the theoretical position range of the projection of each light spot of the optical module after the adjustment; and determining a calibration result of the laser radar according to the new lens distortion parameter or the new distortion center principal point. According to the invention, the problem of consistency of lens parameters and optical module assembly adjustment can be solved, so that the calibration precision of the laser radar can be improved.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a laser radar lens distortion calibration method, device, medium and computer equipment. Background Art

[0002] Unlike hybrid solid-state LiDAR, pure solid-state LiDAR that uses the Flash solution uses optical lenses that are significantly different from hybrid solid-state LiDAR. For hybrid solid-state radar, a larger field of view is achieved through devices such as motors, and the optical lens itself is only responsible for non-imaging parts such as collimation and spot shaping. The large field of view of the Flash LiDAR is achieved by matching the lens with the image plane chip, and its principle is closer to the imaging principle of the camera. However, lenses with a large field of view are usually accompanied by large distortion, which causes distortion in the restoration of the radar point cloud. Therefore, the calibration of the distortion angle is very important for the restoration of the radar point cloud.

[0003] At present, the distortion correction parameters are usually determined based on the lens design parameters to achieve laser radar lens distortion calibration. However, this method of the prior art does not take into account the consistency of the lens itself, as well as the consistency of the lens and chip assembly in the optical module, which leads to poor calibration results, thus affecting the calibration accuracy of the laser radar, and further resulting in a low yield rate of the optical module, resulting in a lot of material waste. Summary of the invention

[0004] In view of this, the present application provides a laser radar lens distortion calibration method, device, storage medium and computer equipment, the main purpose of which is to solve the consistency problem of lens parameters and optical module assembly and adjustment, thereby improving the calibration accuracy of the laser radar and ensuring the yield rate of the optical module.

[0005] According to the first aspect of the present application, a laser radar lens distortion calibration method is provided, the method comprising:

[0006] Determine the theoretical position range of each light spot projection of the optical module according to the initial lens distortion parameters and the initial distortion center principal point;

[0007] Determine the new lens distortion parameter or the new distortion center principal point of the optical module according to the actual position information and theoretical position range of each light spot projection of the optical module after adjustment;

[0008] The calibration result of the laser radar is determined according to the new lens distortion parameter or the new distortion center principal point.

[0009] According to a second aspect of the present application, a laser radar lens distortion calibration device is provided, the device comprising:

[0010] A first determining unit, used to determine a theoretical position range of each light spot projection of the optical module according to an initial lens distortion parameter and an initial distortion center principal point;

[0011] A second determination unit is used to determine a new lens distortion parameter or a new distortion center principal point of the optical module according to actual position information and a theoretical position range of each light spot projection of the optical module after adjustment;

[0012] The third determination unit is used to determine the calibration result of the laser radar according to the new lens distortion parameter or the new distortion center principal point.

[0013] According to a third aspect of the present application, a storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the above-mentioned laser radar lens distortion calibration method is implemented.

[0014] According to the fourth aspect of the present application, a computer device is provided, including a storage medium, a processor, and a computer program stored on the storage medium and executable on the processor, wherein the processor implements the above-mentioned laser radar lens distortion calibration method when executing the program.

[0015] Through the above-mentioned technical scheme, the present application provides a laser radar lens distortion calibration method, device, storage medium and computer equipment. Compared with the prior art, the theoretical position range of each light spot projection is determined through the initial lens distortion parameters and the initial distortion center principal point, and the lens distortion parameters and the distortion center principal point are corrected according to the relationship between the actual position information of each light spot projection and the corresponding theoretical position range, and the new lens distortion parameters or the new distortion center principal point are determined. This can ensure that the lens distortion parameters of the laser radar after calibration are consistent with the actual distortion parameters, so that the lens has a high consistency, and at the same time can ensure that the optical module is adjusted consistently, thereby improving the calibration accuracy of the laser radar, ensuring the yield of the optical module, and avoiding material waste.

[0016] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0018] Figure 1 A schematic diagram of a process flow of a laser radar lens distortion calibration method provided in an embodiment of the present application is shown;

[0019] Figure 2 A schematic diagram of a surface array vcsel chip provided in an embodiment of the present application is shown;

[0020] Figure 3 A schematic diagram showing the structure of a light spot testing device provided by an embodiment of the present application from one viewing angle is shown;

[0021] Figure 4 A schematic diagram showing the theoretical position range of the light spot projection provided by the embodiment of the present application is shown;

[0022] Figure 5 A schematic diagram of a process for determining new lens distortion parameters or new distortion center principal points provided in an embodiment of the present application is shown;

[0023] Figure 6 A schematic diagram of light spot projection under ideal conditions provided by an embodiment of the present application is shown;

[0024] Figure 7 A schematic projection diagram of the central light spot offset provided in an embodiment of the present application is shown;

[0025] Figure 8 A schematic diagram of projection of other light spot offsets provided in the embodiments of the present application is shown;

[0026] Fig. 9 A schematic diagram of a light spot projection of a new lens distortion parameter provided in an embodiment of the present application is shown;

[0027] Fig.10 A schematic diagram of a light spot projection of a new distortion center principal point provided in an embodiment of the present application is shown;

[0028] Fig.11 A schematic diagram of the overall calibration process provided by an embodiment of the present application is shown;

[0029] Fig.12 A schematic structural diagram of a laser radar lens distortion calibration device provided in an embodiment of the present application is shown. DETAILED DESCRIPTION

[0030] The present application will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict.

[0031] The existing technology does not take into account the consistency of the lens itself, as well as the consistency of the lens and chip assembly in the optical module, which leads to poor calibration results, thereby affecting the calibration accuracy of the lidar, and further resulting in a low yield rate of the optical module, causing a lot of material waste.

[0032] In order to solve the above problems, an embodiment of the present invention provides a laser radar lens distortion calibration method, such as Figure 1 As shown, the method includes:

[0033] Step 10: Determine the theoretical position range of each light spot projection of the optical module according to the initial lens distortion parameters and the initial distortion center principal point.

[0034] The optical module includes a lens and a chip. When the chip specifications are determined, the parameters that affect the pointing angle of each ranging channel of the laser radar include the lens distortion parameters (k1, k2, k3, ..., k n ) and the principal point of the distortion center (x0, y0). The lens distortion parameters and the principal point of the distortion center affect the actual position information of the light spot projection of each channel of the optical module by affecting the pointing angle of each ranging channel. The principal point of the distortion center indicates the coordinates of the center point of the lens corresponding to the point on the chip coordinate system, which represents the degree of alignment between the center point of the chip and the main optical axis of the lens center. Usually, the principal point of the distortion center of a well-adjusted optical module is (0, 0). The lens distortion parameters indicate the distortion characteristics of the lens itself, which can be specifically represented by the coefficients of each order of the radial distortion Taylor expansion. The higher the order of the expansion, the more coefficients there are and the better the fit. Taking the 5th order coefficient as an example, the lens distortion parameters are (k1, k2, k3, k4, k5). LiDAR specifically includes Flash LiDAR.

[0035] The embodiment of the present invention is mainly applicable to the scene of Flash laser radar lens distortion calibration. The execution subject of the embodiment of the present invention is a device or equipment capable of calibrating the Flash laser radar.

[0036] For the embodiment of the present invention, in order to calibrate the laser radar, it is necessary to obtain in advance the initial lens distortion parameters and the initial distortion center principal point, as well as the actual position information of each light spot projection of the optical module, and determine the theoretical position range of each light spot projection of the optical module based on the initial lens distortion parameters and the initial distortion center principal point.

[0037] Among them, the initial lens distortion parameters and the initial distortion center principal point when the optical module is adjusted and aligned are theoretical parameters of the optical lens, that is, standard parameters, which can be obtained from the manufacturer.

[0038] The embodiment of the present invention adopts a planar array vcsel chip as the emitting light source of the Flash laser radar. Figure 2 As shown, the specification of the VCSEL chip is a light-emitting cavity surface with 9 rows and 13 columns. The interval between adjacent light-emitting points in each row and column is 0.0005m, and the coordinates of each point can be expressed by (x, y).

[0039] In order to obtain the actual position information of each light spot projection of the optical module, the embodiment of the present invention further provides a light spot testing device 100, such as Figure 3 As shown, it includes: a base 110; a carrier 120, which is arranged on the base 110 and is used to carry the laser radar; a camera assembly 130, which is arranged on the base 110, and the camera assembly 130 includes a fine-tuning module 132 and a camera 131, and the camera 131 is movably connected to the base 110 through the fine-tuning module 132; wherein, the two cameras 131 are distributed on both sides of the carrier 120. The spot test device 100 also includes: a spot receiving screen, which is arranged at intervals from the base 110 and is located in front of the base 110 (in the positive direction of the Y axis), and the spot receiving screen is opposite to the carrier 120. Therefore, the laser radar installed on the carrier 120 emits laser, and the spot can be displayed on the spot receiving screen, and then the spot can be captured on the spot receiving screen by the camera 131, so that the spot test can be realized.

[0040] Specifically, the light spot testing device 100 includes a base 110, a carrier 120 and a camera assembly 130, wherein the laser radar is installed on the base 110 through the carrier 120, the camera assembly 130 is arranged on the base 110, and the camera 131 of the camera assembly 130 is movably connected to the base 110 through the fine-tuning module 132, thereby, the position of the camera 131 relative to the base 110 can be adjusted by the fine-tuning module 132 to achieve the adjustment of the field of view of the camera 131. With two cameras 131 distributed on both sides of the carrier 120, the positions of the two cameras 131 relative to the base 110 can be adjusted by the fine-tuning module 132, therefore, through the cooperation of the two cameras 131, the sum of the field of view of the two cameras 131 can fully cover the field of view of the laser radar, so as to achieve accurate and rapid detection of the light spot of the laser radar. In addition, the light spot receiving screen and the base 110 of the embodiment of the present invention are arranged at intervals, that is, the light spot receiving screen and the base 110 are two separate components. In this way, the light spot receiving screen can be placed at a suitable position in front of the base 110 according to the test accuracy requirements of the laser radar, so as to meet the test accuracy requirements of different laser radars, or meet the different test accuracy requirements of the same laser radar, thereby expanding the scope of application and being suitable for popularization and application.

[0041] The light spot testing device 100 provided in the embodiment of the present invention has a simple structure and is easy to operate. It can reduce the manufacturing cost of the light spot testing device 100 and quickly test the light spot of the laser radar, thereby greatly improving the light spot detection efficiency of the laser radar before leaving the factory.

[0042] When using the above-mentioned light spot testing device, the embodiment of the present invention first fixes the laser radar on the supporting frame, and then adjusts the rotation angle of the camera relative to the base and the flip angle of the camera through the fine-tuning module, so that the sum of the field of view angles of the two cameras covers the field of view angle of the laser radar, and then controls the laser radar to emit laser to the light spot receiving screen of the light spot testing device, and finally controls the camera to capture the light spot on the light spot receiving screen of the light spot testing device, so as to obtain the actual position information of each light spot projection.

[0043] Furthermore, since the initial lens distortion parameters and the initial distortion center principal point are known, the theoretical position range of each light spot projection can be inferred based on the initial lens distortion parameters and the initial distortion center principal point. For this process, step 20 specifically includes: obtaining the installation position information of the optical module, the installation position information of the camera, and the installation position information of the light spot receiving screen; according to the installation position information of the optical module, the installation position information of the camera, the installation position information of the light spot receiving screen, the initial lens distortion parameters and the initial distortion center principal point, determine the theoretical position range of each light spot projection.

[0044] For example, the initial lens distortion parameters are (-83354.5451, -1.22608e+10, 1.13298e+15, 1, 1), and the initial distortion center principal point is (0, 0). At this time, based on the initial lens distortion parameters and the initial distortion center principal point, the pointing angles of each ranging channel under ideal conditions can be obtained. At the same time, combined with the installation position information of the optical module, camera and light spot receiving screen, the theoretical position of each light spot projection at the pixel level can be inferred (for example, through optical simulation), that is, the theoretical position of the center point of the light spot captured by the camera. Based on the theoretical position of the center point of the light spot and the artificially set allowable error range, the theoretical position range of each light spot projection at the pixel level (that is, in the image captured by the camera) can be determined. Figure 4 As shown, the theoretical position range of the light spot projection formed by each channel of the optical module is a circle with the center point of the light spot as the center and the allowable error as the radius. The size of the theoretical position range (circle) can be adjusted according to the allowable error range.

[0045] Step 20: Determine new lens distortion parameters or a new distortion center principal point of the optical module according to actual position information and theoretical position range of each light spot projection of the assembled optical module.

[0046] According to the embodiment of the present invention, the optical module is assembled using Figure 3The device uses a camera to capture the actual position information of each light spot projected on the light spot receiving screen, and can determine whether the projection position of each light spot is within the corresponding theoretical position range. According to the determination result, the lens distortion parameter correction or the distortion center principal point correction is performed to determine the new lens distortion parameter or new distortion center principal point of the optical module.

[0047] The process of determining the new lens distortion parameters or the new distortion center principal point is as follows: Figure 5 As shown, including:

[0048] Step 21: According to the actual position information of the center point light spot among the light spots, determine whether the center point light spot is projected within the corresponding theoretical position range.

[0049] The number of the central point light spots may be one, two or four.

[0050] For the embodiment of the present invention, the center point light spot is the center of all light spots, and the number of the center point light spots mainly depends on the arrangement of the light source array of the chip. If the light source is an odd number of rows and an odd number of columns, the number of the center point light spots is one; if the light source is an odd number of rows and an even number of columns or an even number of rows and an odd number of columns, the number of the center point light spots is two; if the light source is an even number of rows and an even number of columns, the number of the center point light spots is four. In addition, according to the distance between each light spot and the center point of the lens, one, two or four light spots closest to the center point of the lens can be selected from each light spot as the center point light spot. When the number of the center point light spots is two or four, the center point light spots are usually symmetrically distributed around the center point of the lens. Therefore, according to the arrangement of the light source array and the distance between each light spot and the center point of the lens, the center point light spot can be determined.

[0051] After determining the center spot, determine whether the center spot is projected within the corresponding theoretical position range, that is, the corresponding circle, according to the actual position information of the center spot. If the center spot is not projected within the corresponding theoretical position range, then further determine whether the remaining spots except the center spot are projected within the corresponding theoretical position range. If the remaining spots are also projected within the corresponding theoretical position range, it means that all spots are projected within the corresponding theoretical position range. Figure 6 As shown, all the light spots are within the circle. At this time, the optical module can be determined as a first-class qualified product, that is, a product with accurate distortion parameters and principal points. The initial lens distortion parameters and initial distortion center principal points can be directly used without the need to correct the lens distortion parameters and the distortion center principal points.

[0052] In a specific application scenario, if the number of center point light spots is one, it is only necessary to determine whether one center point light spot is within the corresponding theoretical position range; if the number of center point light spots is two or four, it is necessary to determine whether each center point light spot is projected within the corresponding theoretical position range. Each center point light spot must be projected within the corresponding theoretical position range before the center point light spot is considered to meet the requirements. Then, based on the actual position information of the remaining light spots except the two or four center point light spots, it is determined whether the remaining light spots are projected within the corresponding theoretical position range.

[0053] Step 22: If the center point light spot is not projected within the corresponding theoretical position range, the initial distortion center principal point is adjusted to determine the new distortion center principal point.

[0054] In the embodiment of the present invention, when at least one central spot is not projected within the corresponding theoretical position range, Figure 7 As shown, if the initial distortion center principal point is still used, an angle deviation will be caused. Based on this, the embodiment of the present invention chooses to only use the initial lens distortion parameters and adjust the initial distortion center principal point.

[0055] For this process, step 32 specifically includes: determining the traversal range of the distortion center principal point according to the detection range and detection accuracy of the laser radar; within the traversal range of the distortion center principal point, continuously adjusting the initial distortion center principal point by a preset step size each time to obtain multiple adjusted distortion center principal points; for each of the multiple adjusted distortion center principal points, respectively calculating the second total distance difference between the projection position of each light spot and the corresponding theoretical position range; determining the minimum total distance difference from the second total distance differences corresponding to the multiple adjusted distortion center principal points; and determining the adjusted distortion center principal point corresponding to the minimum total distance difference as the new distortion center principal point.

[0056] The traversal range of the distortion center principal point is related to the detection range and detection accuracy of the laser radar. The wider the detection range of the laser radar and the higher the detection accuracy, the larger the traversal range; on the contrary, the smaller the detection range of the laser radar and the lower the detection accuracy, the smaller the traversal range. The preset progress range can be set according to actual business needs.

[0057] Assume that we choose to use the initial lens distortion parameters (k1, k2, k3, ..., k n), and at the same time, within a certain range, adjust the position of the initial distortion center principal point (x0, y0) in a traversal manner. For example, taking the initial distortion center principal point (x0, y0) as the starting point, within the traversal range (-T, T), that is, within the square surrounded by the four points (x0-T, y0-T), (x0+T, y0-T), (x0-T, y0+T) and (x0+T, y0+T), adjust the preset step amplitude t each time, so as to gradually adjust the position of the distortion center principal point (x0, y0). For example, the first adjustment obtains (x0+t, y0), and the second adjustment obtains (x0+t, y0+t)......., and the adjustment is continuously performed with (-T, T) as the boundary. For each step, for the adjusted distortion center principal point, the second total distance difference δ between the projection position of each light spot and the corresponding theoretical position range is calculated, and the second total distance difference δ is the sum of the distances between all light spots and the theoretical light spot centers corresponding to each light spot. Then, the adjusted distortion center principal point corresponding to the minimum δ is selected as the new distortion center principal point, such as the new distortion center principal point is (0.00015, 0.00011).

[0058] In the embodiment of the present invention, when the center spot is offset, the distortion center principal point is gradually adjusted to determine a new distortion center principal point, thereby ensuring the consistency of the optical module adjustment.

[0059] In order to further ensure the accuracy of the calibration results, the embodiment of the present invention can also set the maximum value δmax of the second total distance difference δ. If the second total distance difference δ obtained by traversing all adjusted distortion center principal points is greater than the maximum value δmax, the optical module is determined to be a defective product.

[0060] Step 23: If the center point light spot is projected within the corresponding theoretical position range, determine whether the remaining light spots are projected within the corresponding theoretical position range according to the actual position information of the remaining light spots except the center point light spot.

[0061] For the embodiment of the present invention, after determining that the central light spot is projected in the corresponding theoretical position range, it is necessary to further determine whether the remaining light spots are projected in the corresponding theoretical position range. For this process, step 33 specifically includes: calculating the distance difference between the remaining light spots and the corresponding theoretical position range according to the actual position information of the remaining light spots; calculating the first total distance difference according to the distance difference corresponding to the remaining light spots; if the first total distance difference is less than the first preset threshold, determining that the remaining light spots are projected in the corresponding theoretical position range; if the first total distance difference is greater than or equal to the first preset threshold, determining that the remaining light spots are not projected in the corresponding theoretical position range.

[0062] Among them, the first preset threshold can be set according to actual business needs.

[0063] When specifically calculating the distance difference corresponding to the remaining light spots, the center of the circle corresponding to the corresponding theoretical position range can be determined first, and then the distance difference between the remaining light spots and their corresponding theoretical position ranges can be calculated based on the actual position information of the remaining light spots and the position information of the center of the circle. For example, the coordinates of the actual light spot A are (x1, y1), and the theoretical light spot A' corresponding to the actual light spot A, that is, the coordinates of the center of the circle are (x1', y1'), then the distance difference for A is And so on. Then, the distance differences corresponding to all the light spots are summed to obtain a first total distance difference. If the first total distance difference is less than the first preset threshold, it is determined that the remaining light spots are projected within the corresponding theoretical position range; if the first total distance difference is greater than or equal to the first preset threshold, it is determined that the remaining light spots are not projected within the corresponding theoretical position range.

[0064] Step 24: If the remaining light spots are not projected within the corresponding theoretical position range, the new lens distortion parameters are obtained according to the actual position information of each light spot.

[0065] For the embodiment of the present invention, when the remaining light spots are not projected within the corresponding theoretical position range, such as Figure 8 As shown, if the initial lens distortion parameters are continued to be used at this time, angle deviation will be caused. Based on this, the embodiment of the present invention chooses to use only the initial distortion center principal point, and re-determines the new lens distortion parameters by Taylor expansion fitting. For this process, step 34 specifically includes: calculating the radius of curvature according to the actual position information of each light spot; fitting based on the radius of curvature, the actual position information of each light spot and the projection position information of each light source on the light-emitting cavity surface of the chip in the optical module when no distortion occurs, to obtain the new lens distortion parameters.

[0066] Specifically, the embodiment of the present invention may determine the new lens distortion parameter by using a Taylor expansion fitting method. Taking a fifth-order Taylor expansion as an example, the formula is as follows:

[0067]

[0068] Among them, (x ′ ,y ′ ) is the projection position information of each light source when it is not distorted, that is, the position information of each light source directly projected onto the light spot receiving screen without lens distortion. Since the installation positions of the chip, camera and light spot receiving screen, as well as the positions of each light source on the chip are known, it is possible to infer the position information of each light source directly projected onto the light spot receiving screen without divergence or distortion; (x, y) is the actual position information of each light spot; r is the radius of curvature; (k1, k2, k3, k4, k5) are the new lens distortion parameters. Therefore, the new lens distortion parameters can be fitted according to the above Taylor expansion.

[0069] For example, according to the coefficients of each order of Taylor expansion, the new lens distortion parameters are determined to be (3.0173e+4, -4.4366e+8, 1.4408e+14, 3.7413e+9, 6.8322e+4), and the initial distortion center principal point (0, 0) is continued to be used.

[0070] It should be noted that the number of new lens distortion parameters depends on the order of Taylor expansion. The higher the order, the greater the number of new lens distortion parameters. The order of Taylor expansion can be set according to actual business needs. The higher the order, the higher the fitting accuracy, but the greater the amount of calculation.

[0071] In the embodiment of the present invention, when the remaining light spots are offset, the lens distortion parameters are determined through Taylor expansion fitting, so as to ensure that the lens parameters meet the theoretical requirements, that is, the consistency problem of the lens parameters can be solved.

[0072] Step 30: Determine the calibration result of the laser radar according to the new lens distortion parameter or the new distortion center principal point.

[0073] For the embodiment of the present invention, after determining the new lens distortion parameter or the new distortion center principal point, it is necessary to further determine whether each light spot can achieve the expected projection effect based on the new lens distortion parameter or the new distortion center principal point. If the expected projection effect can be achieved, the final calibration is completed. For this process, step 40 specifically includes: calculating the third total distance difference between the projection position of each light spot under the new lens distortion parameter or the new distortion center principal point and the corresponding theoretical position range; if the third total distance difference is less than the second preset threshold, the new lens distortion parameter and the initial distortion center principal point are burned into the laser radar as the calibration result, or the initial lens distortion parameter and the new distortion center principal point are burned into the laser radar as the calibration result, and the laser radar is determined to be a qualified product; if the third total distance difference is greater than or equal to the second preset threshold, the laser radar is determined to be a failed product.

[0074] The second preset threshold can be set according to actual business needs.

[0075] If the third total distance difference between the projection position of each light spot and the corresponding theoretical position range under the new lens distortion parameters is less than the second preset threshold, it means that the new angle matrix generated based on the new lens distortion parameters and the initial distortion center principal point is accurate, and it can be determined as a second-class qualified product. Although the angle is different from that of the first-class qualified product, the new lens distortion parameters and the initial distortion center principal point are burned into the laser radar as the calibration results, and the accuracy of the laser radar angle can still be guaranteed. Fig. 9As shown, it can be seen that the actual position of the light spot is highly consistent.

[0076] If the third total distance difference between the projection position of each light spot and the corresponding theoretical position range under the new distortion center principal point is less than the second preset threshold, it means that the new angle matrix generated based on the new distortion center principal point and the initial lens distortion parameters used is accurate, and it can be determined as a third-class qualified product. Although the angle is different from that of the first-class qualified product, the new distortion center principal point and the initial lens distortion parameters used are burned into the laser radar as the calibration results, and the accuracy of the laser radar angle can still be guaranteed, such as Fig.10 As shown in FIG. 1 , it can be seen that the actual position of the light spot has a high degree of fit. The overall calibration process of the embodiment of the present invention is as follows: Fig.11 shown.

[0077] A laser radar lens distortion calibration method provided by an embodiment of the present invention determines the theoretical position range of each light spot projection through the initial lens distortion parameters and the initial distortion center principal point, and performs lens distortion parameter correction and distortion center principal point correction according to the relationship between the actual position information of each light spot projection and the corresponding theoretical position range, and determines new lens distortion parameters or new distortion center principal point, which can ensure that the lens distortion parameters of the laser radar after calibration are consistent with the theoretical distortion parameters, so that the lens has high consistency, and at the same time can ensure that the optical module is adjusted consistently, thereby improving the calibration accuracy of the laser radar, ensuring the yield of the optical module, and avoiding material waste.

[0078] Further, as Figure 1 and Figure 5 The specific implementation of the method shown in the embodiment provides a laser radar lens distortion calibration device, such as Fig.12 As shown, the device includes: a first determining unit 101, a second determining unit 102 and a third determining unit 103.

[0079] The first determination unit 101 may be used to determine a theoretical position range of each light spot projection of the optical module according to the initial lens distortion parameter and the initial distortion center principal point.

[0080] The second determination unit 102 may be used to determine new lens distortion parameters or a new distortion center principal point of the optical module according to actual position information and theoretical position range of each light spot projection of the assembled optical module.

[0081] The third determination unit 103 can be used to determine the calibration result of the laser radar according to the new lens distortion parameter or the new distortion center principal point.

[0082] In some embodiments, the second determination unit 102 includes: a determination module and a determination module.

[0083] The determination module may be used to determine whether the center point light spot is projected within a corresponding theoretical position range according to actual position information of the center point light spot among the light spots.

[0084] The determination module may also be used to determine whether the projection of the central point light spot is within the corresponding theoretical position range according to the actual position information of the remaining light spots except the central point light spot among the light spots if the projection of the central point light spot is within the corresponding theoretical position range.

[0085] The determination module may be configured to obtain the new lens distortion parameter according to actual position information of each light spot if the remaining light spots are not projected within the corresponding theoretical position range.

[0086] In some embodiments, when there are two or four central point light spots, the determination module may be specifically configured to determine whether each central point light spot is projected within a corresponding theoretical position range according to actual position information of the two or four central point light spots;

[0087] The determination module can also be specifically used to determine whether the remaining light spots are projected within the corresponding theoretical position range based on actual position information of the remaining light spots except the two or four center point light spots if each of the center point light spots is projected within the corresponding theoretical position range.

[0088] In some embodiments, the second determining unit 102 further includes: an adjustment module.

[0089] The adjustment module may be used to adjust the initial distortion center principal point if the center point light spot is not projected within the corresponding theoretical position range, so as to determine the new distortion center principal point.

[0090] In some embodiments, the determination module can also be specifically used to calculate the distance difference between the remaining light spots and the corresponding theoretical position range based on the actual position information of the remaining light spots; calculate a first total distance difference based on the distance differences corresponding to the remaining light spots; if the first total distance difference is less than a first preset threshold, it is determined that the remaining light spots are projected in the corresponding theoretical position range; if the first total distance difference is greater than or equal to the first preset threshold, it is determined that the remaining light spots are not projected in the corresponding theoretical position range.

[0091] In some embodiments, the determination module can be specifically used to calculate the radius of curvature based on the actual position information of each light spot; and perform fitting based on the radius of curvature, the actual position information of each light spot and the projection position information of each light source on the light-emitting cavity surface of the chip in the optical module when no distortion occurs, so as to obtain the new lens distortion parameters.

[0092] In some embodiments, the adjustment module can be specifically used to determine the traversal range of the distortion center principal point according to the detection range and detection accuracy of the laser radar; within the traversal range of the distortion center principal point, the initial distortion center principal point is continuously adjusted at a preset step size each time to obtain multiple adjusted distortion center principal points; for each of the multiple adjusted distortion center principal points, the second total distance difference between the projection position of each light spot and the corresponding theoretical position range is calculated; the minimum total distance difference is determined from the second total distance differences corresponding to the multiple adjusted distortion center principal points; and the adjusted distortion center principal point corresponding to the minimum total distance difference is determined as the new distortion center principal point.

[0093] In some embodiments, the third determination unit 103 may be specifically used to calculate a third total distance difference between the actual projection position of each light spot and the corresponding theoretical position range under the new lens distortion parameter or the new distortion center principal point;

[0094] If the third total distance difference is less than the second preset threshold, the new lens distortion parameters and the initial distortion center principal point are burned into the laser radar as the calibration result, or the initial lens distortion parameters and the new distortion center principal point are burned into the laser radar as the calibration result, and the laser radar is determined to be a qualified product; if the third total distance difference is greater than or equal to the second preset threshold, the laser radar is determined to be an unqualified product.

[0095] It should be noted that for other corresponding descriptions of the functional units involved in the laser radar lens distortion calibration device provided in this embodiment, please refer to Figure 1 and Figure 5 The corresponding description in will not be repeated here.

[0096] Based on the above Figure 1 and Figure 5 The method shown in the embodiment also provides a storage medium on which a computer program is stored. When the program is executed by a processor, the above-mentioned Figure 1 and Figure 5 The lidar lens distortion calibration method shown.

[0097] Based on this understanding, the technical solution of the present application can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, USB flash drive, mobile hard disk, etc.), including a number of instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute the methods of various implementation scenarios of the present application.

[0098] Based on the above Figure 1 and Figure 5 The method shown, and Fig.12 In order to achieve the above-mentioned purpose, the embodiment of the present application also provides a computer device, which can be a personal computer, a tablet computer, a server, or other network devices, etc. The device includes a storage medium and a processor; the storage medium is used to store a computer program; the processor is used to execute the computer program to achieve the above-mentioned Figure 1 and Figure 5 The lidar lens distortion calibration method shown.

[0099] Optionally, the above-mentioned physical device may also include a user interface, a network interface, a camera, a radio frequency (RF) circuit, a sensor, an audio circuit, a WI-FI module, etc. The user interface may include a display, an input unit such as a keyboard, etc., and the optional user interface may also include a USB interface, a card reader interface, etc. The network interface may optionally include a standard wired interface, a wireless interface (such as a WI-FI interface), etc.

[0100] Those skilled in the art will appreciate that the above-mentioned physical device structure provided in this embodiment does not constitute a limitation on the physical device, and may include more or fewer components, or a combination of certain components, or different arrangements of components.

[0101] The storage medium may also include an operating system and a network communication module. The operating system is a program that manages the hardware and software resources of the above-mentioned physical device, and supports the operation of the information processing program and other software and / or programs. The network communication module is used to realize the communication between the components inside the storage medium, and the communication with other hardware and software in the information processing physical device.

[0102] Through the description of the above implementation methods, those skilled in the art can clearly understand that the present application can be implemented by means of software plus a necessary general hardware platform, or by hardware.

[0103] The embodiment of the present invention determines the theoretical position range of each light spot projection through the initial lens distortion parameters and the initial distortion center principal point, and performs lens distortion parameter correction and distortion center principal point correction according to the relationship between the actual position information of each light spot projection and the corresponding theoretical position range, and determines new lens distortion parameters or new distortion center principal point, which can ensure that the lens distortion parameters of the laser radar after calibration are consistent with the theoretical distortion parameters, so that the lens has a high consistency, and at the same time can ensure that the optical module is adjusted consistently, thereby improving the calibration accuracy of the laser radar, ensuring the yield rate of the optical module, and avoiding material waste.

[0104] Those skilled in the art will appreciate that the accompanying drawings are only schematic diagrams of a preferred implementation scenario, and the modules or processes in the accompanying drawings are not necessarily necessary for implementing the present application. Those skilled in the art will appreciate that the modules in the devices in the implementation scenario can be distributed in the devices of the implementation scenario according to the description of the implementation scenario, or can be changed accordingly and located in one or more devices different from the present implementation scenario. The modules of the above-mentioned implementation scenario can be combined into one module, or can be further split into multiple submodules.

[0105] The above serial numbers of this application are only for description and do not represent the advantages and disadvantages of the implementation scenarios. The above disclosure is only a few specific implementation scenarios of this application, but this application is not limited to them, and any changes that can be thought of by technicians in this field should fall within the scope of protection of this application.

Claims

1. A laser radar lens distortion calibration method, characterized in that: include: Determine the theoretical position range of each light spot projection of the optical module according to the initial lens distortion parameters and the initial distortion center principal point; Determine the new lens distortion parameter or the new distortion center principal point of the optical module according to the actual position information and theoretical position range of each light spot projection of the optical module after adjustment; A calibration result is determined according to the new lens distortion parameter or the new distortion center principal point.

2. The method according to claim 1, characterized in that Determining new lens distortion parameters or new distortion center principal points of the optical module according to actual position information and theoretical position range of each light spot projection of the optical module after adjustment includes: According to the actual position information of the center point light spot among the light spots, determining whether the center point light spot is projected within the corresponding theoretical position range; If the center point light spot is projected within the corresponding theoretical position range, then judging whether the remaining light spots are projected within the corresponding theoretical position range according to the actual position information of the remaining light spots except the center point light spot among the light spots; If the remaining light spots are not projected within the corresponding theoretical position range, the new lens distortion parameter is obtained according to the actual position information of each light spot.

3. The method according to claim 1, characterized in that The method further comprises: If the center point light spot is not projected within the corresponding theoretical position range, the initial distortion center principal point is adjusted to determine the new distortion center principal point.

4. The method according to claim 2, characterized in that: The determining, based on actual position information of the remaining light spots except the central light spot among the light spots, whether the remaining light spots are projected within a corresponding theoretical position range comprises: Calculating the distance difference between the remaining light spots and the corresponding theoretical position range according to the actual position information of the remaining light spots; Calculating a first total distance difference according to the distance differences corresponding to the remaining light spots; If the first total distance difference is less than a first preset threshold, determining that the remaining light spots are projected within a corresponding theoretical position range; If the first total distance difference is greater than or equal to the first preset threshold, it is determined that the remaining light spots are not projected within the corresponding theoretical position range.

5. The method according to claim 2, characterized in that: The obtaining of the new lens distortion parameter according to the actual position information of each light spot includes: Calculating the radius of curvature according to the actual position information of each light spot; Based on the curvature radius, the actual position information of each light spot and the projection position information of each light source on the light emitting cavity surface of the chip in the optical module when no distortion occurs, fitting is performed to obtain the new lens distortion parameter.

6. The method according to claim 3, characterized in that The step of gradually adjusting the initial distortion center principal point to determine the new distortion center principal point includes: Determine the traversal range of the distortion center principal point; Within the distortion center principal point traversal range, the initial distortion center principal point is continuously adjusted with a preset step size each time to obtain a plurality of adjusted distortion center principal points; For each adjusted distortion center principal point, respectively calculating a second total distance difference between the projection position of each light spot and the corresponding theoretical position range; Determine a minimum total distance difference from the second total distance differences respectively corresponding to the plurality of adjusted distortion center principal points; The adjusted distortion center principal point corresponding to the minimum total distance difference is determined as the new distortion center principal point.

7. The method according to claim 1, characterized in that The determining the calibration result according to the new lens distortion parameter or the new distortion center principal point includes: Calculating a third total distance difference between an actual projection position of each light spot and a corresponding theoretical position range under the new lens distortion parameter or the new distortion center principal point; If the third total distance difference is less than a second preset threshold, the new lens distortion parameter and the initial distortion center principal point are burned into the laser radar as a calibration result, or the initial lens distortion parameter and the new distortion center principal point are burned into the laser radar as a calibration result, and the laser radar is determined to be a qualified product; If the third total distance difference is greater than or equal to the second preset threshold, the laser radar is determined to be a defective product.

8. A laser radar lens distortion calibration device, characterized in that: include: A first determining unit, used to determine a theoretical position range of each light spot projection of the optical module according to an initial lens distortion parameter and an initial distortion center principal point; A second determination unit is used to determine a new lens distortion parameter or a new distortion center principal point of the optical module according to actual position information and a theoretical position range of each light spot projection of the optical module after adjustment; The third determining unit is used to determine a calibration result according to the new lens distortion parameter or the new distortion center principal point.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer device comprising a storage medium, a processor, and a computer program stored in the storage medium and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

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