Active alignment method for light-receiving and light-emitting circuit, electronic device and readable storage medium

Abstract

The present application discloses a method for actively aligning a light-receiving and light-emitting circuit, an electronic device, and a readable storage medium. The method comprises: obtaining N frames of first point clouds, wherein the N frames of first point clouds correspond one-to-one to N first candidate positions of a transmitting plate spaced apart along a first direction; selecting a first region, M second regions, and M third regions arranged in sequence along the first direction in the first point cloud; obtaining a first evaluation function value curve for the first region, a second evaluation function curve for the second region, and a third evaluation function value curve for the third region based on the reflectivity information of the N frames of first point clouds; and obtaining a target positioning position of the transmitting plate based on the first evaluation function value curve, the M second evaluation function curves, and the M third evaluation function value curves. Through the above-mentioned method, an evaluation function can be designed based on the reflectivity information to determine the degree of transceiver alignment, and the optimal position can be determined based on the results of the partition calculation, which helps to achieve precise adjustment and height alignment of the light-receiving and light-emitting circuit.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of laser radar technology, and in particular to a method for actively aligning a light-receiving and light-emitting circuit, an electronic device, and a readable storage medium. Background Art

[0002] Active Alignment (AA) is a technology used in optical systems, particularly during the assembly of LiDAR and sensors, to ensure accurate alignment of optical components. This technology typically uses precise mechanical adjustments with real-time feedback to adjust the position and angle of optical components to achieve optimal beam alignment or precise configuration of the optical system. In LiDAR systems, AA is often used to align laser transmitters and receivers to ensure accurate transmission and reception of laser beams, thereby improving measurement accuracy and system performance. Summary of the Invention

[0003] The embodiments of the present application provide a method for active alignment of a light transmitting and receiving circuit, an electronic device, and a readable storage medium. These methods can design an evaluation function based on reflectivity information to determine the degree of transceiver alignment, and determine the optimal position based on the results of partition calculations. This helps to achieve precise adjustment and height alignment of the light transmitting and receiving circuits, thereby improving the performance and reliability of the entire system.

[0004] In a first aspect, an embodiment of the present application provides an active alignment method for a light-receiving and light-emitting circuit applied to a laser radar, wherein the laser radar includes a transmitting board, and the method includes: obtaining N frames of first point clouds collected by the laser radar, wherein N is a positive integer, and the N frames of first point clouds correspond one-to-one to N first candidate positions of the transmitting board, and the N first candidate positions are arranged at intervals along a first direction, and the first direction is perpendicular to the horizontal plane where the optical axis of the laser radar is located or perpendicular to the vertical plane where the optical axis is located; selecting a first area, M second areas and M third areas in the first point cloud, wherein the second area, the first area and the third area are arranged in sequence along the first direction, and M is a positive integer; according to the reflectivity information of the N frames of the first point cloud, obtaining a first evaluation function value curve of the first area, a second evaluation function curve of the M second areas and a third evaluation function value curve of the M third areas, wherein the evaluation function value curve represents the correspondence between the evaluation function value and the first candidate position; according to the first evaluation function value curve, the M second evaluation function curves and the M third evaluation function value curves, obtaining the target positioning position of the transmitting board.

[0005] This method, which uses reflectivity information to design an evaluation function to determine the degree of transceiver alignment, is applicable to all DTOF (Direct Time of Flight) LiDAR systems. It quickly and easily achieves active alignment of the LiDAR's light and receiver paths, enabling automated light adjustment. Furthermore, determining the optimal position based on the partitioning calculation facilitates precise adjustment and alignment of the light and receiver paths, improving overall system performance and reliability.

[0006] In one or more embodiments, the target positioning position of the launch plate is obtained according to the first evaluation function value curve, M second evaluation function curves and M third evaluation function value curves, including: obtaining the first peak point of the first evaluation function value curve, the second peak points of the M second evaluation function curves and the third peak points of the M third evaluation function value curves; determining the target positioning position according to the first peak point, the M second peak points and the M third peak points.

[0007] According to the position corresponding to the first peak point, the position with the best point cloud quality in the first area can be obtained. According to the M second peak points and the M third peak points, the position with the best overall point cloud quality can be obtained. In this way, the target positioning position determined by combining the first peak point, M second peak points and M third peak points can take into account both the center and the overall point cloud quality, which is conducive to the precise adjustment and height alignment of the light receiving and light paths, and improves the performance and reliability of the entire system.

[0008] In one or more embodiments, a target positioning position is obtained based on a first peak point, M second peak points, and M third peak points, including: determining a first positioning position among N first candidate positions based on the first peak point; determining M second positioning positions among N first candidate positions based on the M second peak points; determining M third positioning positions among N first candidate positions based on the M third peak points; calculating the average value of the coordinates of the M second positioning positions and the coordinates of the M third positioning positions to determine a fourth positioning position; and obtaining the target positioning position based on the first positioning position and the fourth positioning position.

[0009] The first positioning position is the position with the best point cloud quality in the first area, and the fourth positioning position is the position with the best overall point cloud quality. Combining the first positioning position with the fourth positioning position for analysis not only considers local details but also the overall structure, and can obtain a target positioning position that takes into account both the central point cloud quality and the overall point cloud quality, effectively improving the accuracy and robustness of the target positioning position, and facilitating the precise adjustment and height alignment of the light-receiving and light-emitting paths, thereby improving the performance and reliability of the entire system.

[0010] In one or more embodiments, obtaining the target positioning position based on the first positioning position and the fourth positioning position includes: obtaining the minimum value between the absolute value of the difference between the coordinates of the first positioning position and the coordinates of the fourth positioning position and a first preset threshold; and obtaining the target positioning position based on the sum or difference between the coordinates of the first positioning position and the minimum value.

[0011] The absolute value of the difference between the coordinates of the first positioning position and the coordinates of the fourth positioning position is used to represent the deviation between the first positioning position and the fourth positioning position. When the deviation is less than or equal to the first preset threshold, the target positioning position obtained by using the sum or difference of the coordinates of the first positioning position and the deviation can have better central point cloud quality and overall point cloud quality at the same time.

[0012] In one or more embodiments, after obtaining the target positioning position of the launch plate, the method also includes: when the launch plate is located at the target positioning position, obtaining a second point cloud collected by the laser radar; selecting an area of ​​interest in the second point cloud, wherein the area of ​​interest includes at least one point cloud block, and the point cloud block includes J rows and K columns of point cloud points, and J and K are both positive integers; obtaining the maximum and minimum values ​​of the reflectivity of each row of point cloud points or each column of point cloud points in each point cloud block; obtaining the point cloud contrast of the area of ​​interest based on the maximum and minimum values ​​corresponding to each point cloud block; and determining the distribution state of the reflectivity of the second point cloud based on the point cloud contrast of the area of ​​interest.

[0013] Checking the reflectivity distribution of the second point cloud, a different approach from the previous optical path calibration process, effectively confirms the success of the aforementioned optical path calibration process. If the reflectivity distribution matches expectations, the light and light paths are correctly aligned, helping to ensure the accuracy and reliability of the alignment.

[0014] In one or more embodiments, the point cloud contrast of the area of ​​interest is obtained based on the maximum and minimum values ​​corresponding to each point cloud block, including: determining J first differences in each point cloud block, wherein the first difference is the difference between the maximum and minimum values ​​of the reflectivity of a single row of point cloud points; determining the point cloud contrast of each point cloud block based on the average value of the J first differences; and obtaining the point cloud contrast of the area of ​​interest based on the average value of the point cloud contrasts of each point cloud block.

[0015] Based on the average value of the J first differences, the maximum fluctuation range of the values ​​in each point cloud block can be determined. Based on the average value of the point cloud contrast of each point cloud block, the maximum fluctuation range of the values ​​in the region of interest can be determined. If the above fluctuation range is small, it means that the changes in different areas within each point cloud block and different areas within the region of interest are smooth, indicating that the distribution state of the reflectivity is in line with expectations, and it can be determined that the light receiving and light transmitting paths are correctly aligned.

[0016] In one or more embodiments, the point cloud contrast of the area of ​​interest is obtained based on the maximum and minimum values ​​corresponding to each point cloud block, including: determining K first ratios for each point cloud block, wherein the first ratio is the ratio of the second difference to the first sum, the second difference is the difference between the maximum and minimum values ​​of the reflectivity of a column of point cloud points, and the first sum is the sum of the maximum and minimum values ​​of the reflectivity of a column of point cloud points; determining the point cloud contrast of each point cloud block based on the average value of the K first ratios; and obtaining the point cloud contrast of the area of ​​interest based on the average value of the point cloud contrasts of each point cloud block.

[0017] Based on the average value of the K first ratios, the maximum fluctuation range of the values ​​in each point cloud block can be determined. Based on the average value of the point cloud contrast of each point cloud block, the maximum fluctuation range of the values ​​in the region of interest can be determined. If the above fluctuation range is small, it means that the changes in different areas within each point cloud block and different areas within the region of interest are smooth, indicating that the distribution state of the reflectivity is in line with expectations, and it can be determined that the light receiving and light transmitting paths are correctly aligned.

[0018] In one or more embodiments, the distribution state includes a normal state and an abnormal state. The distribution state of the reflectivity of the second point cloud is determined based on the point cloud contrast of the area of ​​interest, including: when the point cloud contrast of the area of ​​interest is less than or equal to a second preset threshold, determining that the distribution state of the reflectivity of the second point cloud is a normal state; when the point cloud contrast of the area of ​​interest is greater than the second preset threshold, determining that the distribution state of the reflectivity of the second point cloud is an abnormal state.

[0019] If the point cloud contrast is less than or equal to the second preset threshold, it means that the changes between different areas within each point cloud block and different areas within the region of interest are smooth, indicating that the distribution of reflectivity is as expected, and it can be determined that the light receiving and light receiving paths are correctly aligned.

[0020] In a second aspect, an embodiment of the present application provides an electronic device comprising: at least one processor and a memory; the memory is coupled to the processor, and the memory is used to store instructions or programs. When the instructions or programs are executed by at least one processor, the at least one processor executes the active alignment method of the light-receiving and light-emitting circuit as described above.

[0021] In a third aspect, an embodiment of the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is executed, the active alignment method of the light-transmitting and light-receiving circuit as described above is implemented. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] One or more embodiments are exemplarily described by the figures in the accompanying drawings, which are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0023] Figure 1 This is a flow chart of the active alignment method for the light-receiving and light-emitting circuits provided in an embodiment of the present application;

[0024] Figure 2 Schematic diagram of the first point cloud and evaluation function curves provided in an embodiment of the present application;

[0025] Figure 3 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0026] Figure 4 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0027] Figure 5 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0028] Figure 6 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0029] Figure 7 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0030] Figure 8 is a schematic diagram of a second point cloud and a region of interest provided in an embodiment of the present application;

[0031] Figure 9 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0032] Figure 10 Schematic diagram of an implementation method of the active alignment method of the light-receiving and light-emitting circuit provided in an embodiment of the present application;

[0033] Figure 11 It is a structural diagram of an electronic device provided in an embodiment of the present application.

[0034] Reference numerals:

[0035] PC1, first point cloud; ROI1, first region; ROI2, second region; ROI3, third region; ROI4, region of interest; PC2, second point cloud; BL1, first point cloud block; BL2, second point cloud block; BLT, Tth point cloud block; 1100, electronic device; 1101, processor; 1102, memory. DETAILED DESCRIPTION

[0036] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of them. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application.

[0037] It should be noted that when an element is described as being "connected" to another element, it may be directly connected to the other element, or one or more intermediate elements may be present therebetween. In addition, the technical features involved in the various embodiments of the present application described below may be combined with each other as long as there is no structural conflict between them.

[0038] Automated active alignment of a LiDAR is generally divided into three steps: active transmit alignment, active receive alignment, and active transceiver alignment. The goal of active transceiver alignment is to align the transmit and receive mappings, achieving a one-to-one correspondence between the transmit and receive areas. For example, by designing an evaluation function to quantitatively assess the size of gaps in the point cloud, the degree of transceiver alignment can be quickly and easily assessed, thereby enabling automated light adjustment for the LiDAR.

[0039] Existing LiDAR optical modulation methods include signal modulation and image modulation. Signal modulation uses the signal amplitude at a single pixel as the basis for alignment, as only one signal is collected simultaneously. This method is not suitable for flash LiDAR. Image modulation uses an external light source to illuminate the receiving area, observing and adjusting the relative relationship between the transmitted light spot and the received image in a rangefinder to achieve the desired optical modulation. This modulation method requires identifying feature points in the received image, places high demands on image clarity, and also has limitations.

[0040] Based on this, an embodiment of the present application provides a method for active alignment of the light transmitting and receiving circuits. This method can design an evaluation function based on the reflectivity information of the point cloud to determine the degree of transceiver alignment, and determine the optimal position of the transmitting plate through the results of the partition calculation, thereby realizing precise adjustment and height alignment of the light transmitting and receiving circuits.

[0041] Please refer to Figure 1 , Figure 1A flow chart of a method for actively aligning a light-emitting and light-receiving circuit provided in an embodiment of the present application. The method for actively aligning a light-emitting and light-receiving circuit is applied to a laser radar, which may be a solid-state laser radar, a semi-solid-state laser radar, or the like, and the present application does not impose any sole limitation thereto. A laser radar can be applied to any device that requires laser detection, such as a mobile robot, a ship, or a vehicle. The laser radar includes a transmitting plate for emitting a detection laser and a receiving plate for receiving an echo signal. Specifically, the transmitting plate is capable of emitting a pulsed detection laser, which is projected onto a target object, and a signal formed by reflection from the target object is an echo signal. The receiving plate receives the echo signal and obtains relevant information about the target object based on the echo signal, such as the distance to the target object.

[0042] like Figure 1 As shown, the active alignment method for the light-receiving and light-emitting circuit includes the following method steps S110 to S140:

[0043] Step S110: Obtain N frames of first point clouds collected by the laser radar, where N is a positive integer, and the N frames of first point clouds correspond one-to-one to N first candidate positions of the transmitting plate. The N first candidate positions are spaced apart along a first direction, and the first direction is perpendicular to the horizontal plane where the optical axis of the laser radar is located or perpendicular to the vertical plane where the optical axis is located.

[0044] The first point cloud is obtained by the lidar by emitting detection light and receiving reflected light signals. For example, a flash lidar uses a vertical cavity surface emitting laser array as the emission source and a two-dimensional detector array (such as an avalanche photodiode array or a single photon avalanche diode array) to receive the reflected light signals. Unlike the point-by-point detection method of a mechanically rotating lidar, a flash lidar acquires a point cloud for the entire field of view at once. Specifically, the transmitter plate is translated along a first direction to traverse, obtaining N frames of the first point cloud collected by the lidar when the transmitter plate is at N first candidate positions.

[0045] The optical axis of the lidar is the central axis along which the lidar transmits and receives laser light. With the optical axis as a reference, the horizontal plane is the horizontal plane on which the optical axis lies, and the vertical plane is the vertical plane on which the optical axis lies. In some embodiments, if the horizontal plane is defined by the optical axis and the horizontal direction, then its normal direction (i.e., the first direction) is the vertical direction (e.g., the direction of gravity). In some embodiments, if the vertical plane is defined by the optical axis and the direction of gravity, then its normal direction (i.e., the first direction) is the horizontal transverse direction (perpendicular to both the optical axis and the direction of gravity). In some embodiments, the first direction is the row direction of the laser array on the transmitting board or the column direction of the laser array on the transmitting board. In some embodiments, the first direction is the horizontal direction or the vertical direction.

[0046] Step S120: selecting a first region, M second regions, and M third regions in the first point cloud, wherein the second region, the first region, and the third region are arranged sequentially along a first direction, and M is a positive integer.

[0047] Specifically, the first, second, and third regions are regions selected based on needs, and the sizes of the regions are not specifically limited. In some embodiments, the first point cloud has a centerline, and the first point cloud is symmetrical with respect to the centerline along a first direction. The centerline passes through the first region, and the first region is the region including the center position of the first point cloud and its vicinity. Then, based on the arrangement of the second, first, and third regions along the first direction, the second and third regions are located on either side of the first region, i.e., the second and third regions are located on either side of the center position of the first point cloud and are not passed through by the centerline. Figure 2 The manner in which the first region, the second region, and the third region are selected when M is 1 is exemplified. Figure 2 As shown in the left part of the figure, in the first point cloud PC1, the second region ROI2, the first region ROI1 and the third region ROI3 are selected and arranged in sequence along the first direction (in this embodiment, the direction perpendicular to the horizontal plane where the optical axis of the laser radar is located).

[0048] Step S130: Based on the reflectivity information of the first point cloud of N frames, obtain the first evaluation function value curve of the first area, the second evaluation function curves of M second areas, and the third evaluation function value curves of M third areas, wherein the evaluation function value curve represents the correspondence between the evaluation function value and the first candidate position.

[0049] The point cloud evaluation function is used to evaluate the state of the point cloud, such as the detection rate of the point cloud or the degree of alignment between the transmitting and receiving components, and outputs a corresponding evaluation function value. In some embodiments, the relationship between point cloud quality and the evaluation function value is positively correlated. That is, the larger the evaluation function value, the better the point cloud quality; conversely, the lower the evaluation function value, the worse the point cloud quality.

[0050] Specifically, for the first point cloud in each frame, the grayscale value of each point is obtained based on the reflectivity information of each point in the first point cloud. Reflectivity, also known as reflection intensity, refers to the proportion of energy reflected by an object's surface after the laser beam emitted by the lidar strikes it. Grayscale refers to the brightness level of each pixel in an image. In digital image processing, grayscale values ​​are typically represented by integers from 0 to 255. 0 represents black, 255 represents white, and values ​​in between represent varying shades of gray. Point cloud data itself typically consists of a series of spatial coordinates (x, y, z) and other additional information (such as intensity, color, reflectivity, and timestamps). For point cloud data collected by lidar or optical sensors, grayscale values ​​are typically used to represent the intensity of the reflected signal received by the sensor. In most lidar systems, the grayscale value of a point cloud corresponds to the reflectivity of each point. In some embodiments, the relationship between reflectivity and grayscale is positively correlated, that is, when reflectivity increases, the grayscale increases accordingly; conversely, when reflectivity decreases, the grayscale decreases accordingly. Specifically, when the reflectivity is 100%, the grayscale is 255; when the reflectivity is 0, the grayscale is 0.

[0051] Afterwards, for the first point cloud of each frame, the evaluation function value of each area is calculated based on the point cloud evaluation function and the grayscale values ​​of the point cloud points contained in each area (including the first area, the second area and the third area). Therefore, according to the first point clouds of N frames (corresponding to N first candidate positions), N evaluation function values ​​corresponding to each area can be obtained. In this way, the point cloud evaluation function curve corresponding to each area can be obtained.

[0052] by Figure 2 For example, in Figure 2 In the right part of , the horizontal axis represents the first candidate position, and the vertical axis represents the evaluation function value. Figure 2 As shown, the evaluation function value curve corresponding to the first region ROI1 is the first evaluation function value curve GP1, the evaluation function value curve corresponding to the second region is the second evaluation function curve GP2, and the evaluation function value curve corresponding to the third region is the third evaluation function value curve GP3.

[0053] Step S140: Obtaining the target positioning position of the launch board according to the first evaluation function value curve, the M second evaluation function curves, and the M third evaluation function value curves.

[0054] According to the first evaluation function value curve, the specific situation of the point cloud quality of the middle part (i.e., the center) can be obtained. According to the M second evaluation function curves and the M third evaluation function value curves, the specific situation of the overall point cloud quality can be obtained. Therefore, combining the first evaluation function value curve, the M second evaluation function curves and the M third evaluation function value curves can help to achieve a balance between the center and the overall point cloud quality, so that the obtained target positioning position can achieve a high degree of alignment of the light receiving and light paths.

[0055] In some embodiments, as Figure 3 As shown, the specific implementation process of step S140 includes the following steps S310 to S320:

[0056] Step S310: Obtain a first peak point of the first evaluation function value curve, M second peak points of the second evaluation function curves, and M third peak points of the third evaluation function value curves.

[0057] Step S320: Determine the target positioning position according to the first peak point, the M second peak points, and the M third peak points.

[0058] According to the position corresponding to the first peak point, the position with the best point cloud quality in the first area can be obtained. According to the M second peak points and the M third peak points, the position with the best overall point cloud quality can be obtained. In this way, the target positioning position determined by combining the first peak point, M second peak points and M third peak points can take into account both the center and the overall point cloud quality, which is conducive to the precise adjustment and height alignment of the light receiving and light paths, and improves the performance and reliability of the entire system.

[0059] In some embodiments, as Figure 4 As shown, the specific implementation process of step S320 includes the following steps S410 to S450:

[0060] Step S410: Determine a first positioning position among N first candidate positions according to the first peak point.

[0061] Step S420: Determine M second positioning positions from the N first candidate positions according to the M second peak points.

[0062] Step S430: Determine M third positioning positions from the N first candidate positions according to the M third peak points.

[0063] Step S440: Calculate an average value of the coordinates of the M second positioning positions and the coordinates of the M third positioning positions to determine a fourth positioning position.

[0064] Step S450: Obtain a target positioning position according to the first positioning position and the fourth positioning position.

[0065] by Figure 2 For example, in this case, M = 1. The first candidate position corresponding to the peak point (i.e., the first peak point) of the first evaluation function value curve GP1 is the first positioning position P1. The first candidate position corresponding to the peak point (i.e., the second peak point) of the second evaluation function value curve GP2 is the second positioning position P2. The first candidate position corresponding to the peak point (i.e., the third peak point) of the third evaluation function value curve GP3 is the third positioning position P3. The fourth positioning position P4 is obtained by taking the average of the coordinates of the second positioning position P2 and the third positioning position P3. Finally, the target positioning position is obtained based on the first positioning position P1 and the fourth positioning position P4.

[0066] In this embodiment, the first positioning position P1 is the position with the best point cloud quality in the first area ROI1, and the fourth positioning position P4 is the position with the best overall point cloud quality. The first positioning position P1 and the fourth positioning position P4 are combined for analysis, which not only considers local details but also the overall structure. A target positioning position that takes into account both the central point cloud quality and the overall point cloud quality can be obtained, which effectively improves the accuracy and robustness of the target positioning position, is conducive to the precise adjustment and height alignment of the light receiving and transmitting paths, and improves the performance and reliability of the entire system.

[0067] In some embodiments, as Figure 5 As shown, the specific implementation process of step S450 includes the following steps S510 to S520:

[0068] Step S510: obtaining a minimum value between an absolute value of a difference between the coordinates of the first positioning position and the coordinates of the fourth positioning position and a first preset threshold.

[0069] Step S520: Obtain the target positioning position based on the sum or difference between the coordinates of the first positioning position and the minimum value.

[0070] Specifically, the coordinates of the first positioning position P1 are labeled CP1, and the coordinates of the fourth positioning position P4 are labeled CP4. The target positioning position is: CP1 + min (|CP1 - CP4|, A) or CP1 - min (|CP1 - CP4|, A), where A is a first preset threshold. The first preset threshold is a preset threshold value that can be set based on actual application scenarios and is not specifically limited in this embodiment of the present application. In some embodiments, A is set to any value between 5 μm and 10 μm.

[0071] In this embodiment, on the one hand, the coordinate CP1 of the first positioning position P1 is used as a reference and a smaller value is added to obtain the target positioning position, so that the target positioning position can be close to the first positioning position P1, which is conducive to ensuring better center point cloud quality; on the other hand, the absolute value of the difference between the coordinates of the first positioning position and the coordinates of the fourth positioning position is used to represent the deviation between the first positioning position and the fourth positioning position. When the deviation is less than or equal to the first preset threshold, the target positioning position is obtained by using the sum or difference of the coordinates of the first positioning position and the deviation, which can ensure that the target positioning position is close to the fourth positioning position P4 on the basis of ensuring that the deviation between the target positioning position and the first positioning position P1 is small, which is conducive to improving the overall point cloud quality as much as possible on the basis of obtaining better center point cloud quality.

[0072] In some embodiments, if the absolute value of the difference between the coordinates of the first and fourth positioning locations exceeds a first preset threshold, an alarm signal is output simultaneously with the determination of the target positioning location. This is because the absolute value of the difference between the coordinates of the first and fourth positioning locations exceeds the first preset threshold, which may indicate a component abnormality or defect (such as substandard performance, cosmetic damage, or unqualified parameters). In this case, an alarm is issued to eliminate or repair the abnormal component, eliminating the need for LiDAR assembly from that component, thereby improving work efficiency and ensuring the quality of the final product.

[0073] The above-described embodiment enables active alignment of the light and receiver paths. This approach, which uses reflectivity information to design an evaluation function to determine the degree of alignment, is applicable to all DTOF (Direct Time of Flight) LiDAR systems. It quickly and easily completes active alignment of the light and receiver paths, enabling automated light adjustment. Furthermore, determining the optimal position based on the partitioning calculation facilitates precise adjustment and height alignment of the light and receiver paths, improving overall system performance and reliability.

[0074] Afterwards, the embodiment of the present application also provides a process for verifying the results of the active alignment of the light transmitting and receiving circuits to further improve the reliability of the system. The specific implementation process will be described later.

[0075] In some embodiments, as Figure 6 As shown, after executing step S140 to obtain the target positioning position, the active alignment method of the light receiving and light receiving circuit further includes the following steps S610 to S650:

[0076] Step S610: When the transmitting plate is located at the target positioning position, a second point cloud collected by the laser radar is obtained.

[0077] Specifically, the transmitting plate is fixed at the target positioning position, and then the laser radar transmits detection light and receives reflected light signals, and obtains the second point cloud according to the reflected light signals.

[0078] Step S620: Selecting a region of interest in the second point cloud, wherein the region of interest includes at least one point cloud block, and the point cloud block includes J rows and K columns of point cloud points, where J and K are both positive integers.

[0079] The region of interest (ROI) refers to an area of ​​special significance or requiring special attention, which can be a rectangle, a polygon, or an area of ​​any shape. In this embodiment, the region of interest is taken as a rectangle as an example.

[0080] Step S630: Obtain the maximum and minimum reflectivity values ​​of each row or column of point cloud points in each point cloud block.

[0081] Step S640 : Obtaining the point cloud contrast of the region of interest according to the maximum value and the minimum value corresponding to each point cloud block.

[0082] Step S650: determining the distribution state of the reflectivity of the second point cloud according to the point cloud contrast of the region of interest.

[0083] Specifically, the point cloud contrast of each point cloud block is determined by taking the maximum and minimum reflectivity values ​​of each row (or column) of point cloud points within each point cloud block. The point cloud contrast of the region of interest is then combined with the point cloud contrast of all point cloud blocks within the region of interest. Finally, the reflectivity distribution of the second point cloud is determined based on the point cloud contrast of the region of interest. Point cloud contrast indicates the degree of attribute difference between point clouds in different regions. High point cloud contrast indicates significant differences between adjacent regions, while low point cloud contrast indicates gradual changes. Reflectivity distribution states can be classified into normal and abnormal states. Abnormal states can refer to poor point clouds, manifested in poor alignment, low reflectivity, low detection rate, and low anomaly rate.

[0084] This embodiment uses a different approach than the previously described optical path calibration process to check the reflectivity distribution of the second point cloud, effectively confirming the success of the aforementioned optical path calibration process. If the reflectivity distribution meets expectations, the light and light paths are correctly aligned, helping to ensure the accuracy and reliability of the alignment.

[0085] In some embodiments, as Figure 7 The specific implementation process of step S640 includes the following steps S710 to S730:

[0086] Step S710: In each point cloud block, determine J first difference values, wherein the first difference value is the difference between the maximum value and the minimum value of the reflectivity of a single row of point cloud points.

[0087] Step S720: Determine the point cloud contrast of each point cloud block according to the average value of the J first differences.

[0088] Step S730 : obtaining the point cloud contrast of the region of interest according to the average value of the point cloud contrast of each point cloud block.

[0089] by Figure 8 For example, select ROI4 from the second point cloud PC2. The ROI consists of T point cloud blocks, which include the first point cloud block BL1, the second point cloud block BL2, ..., and the Tth point cloud block BLT, where T is a positive integer. Each point cloud block consists of 4 rows and 8 columns of point cloud points, i.e., J = 4 and K = 8.

[0090] In each point cloud block, the difference between the maximum and minimum reflectivity of the point cloud points in each row determines a first difference, and 4 rows can determine 4 first differences. Calculate the average value of the 4 first differences as the point cloud contrast of the corresponding point cloud block. Since there are T point cloud blocks, the point cloud contrasts corresponding to the T point cloud blocks can be obtained. Calculate the average value of the T point cloud contrasts as the point cloud contrast of the region of interest. It can be understood that this embodiment is explained by taking the point cloud contrast of the region of interest obtained by the point cloud points of each row as an example. In other embodiments, the point cloud contrast of the region of interest can also be obtained by the point cloud points of each column. The specific implementation process is similar to the above embodiment. It is within the scope that can be easily understood by those skilled in the art and will not be repeated here.

[0091] In this embodiment, the maximum fluctuation range of the values ​​in each point cloud block can be determined based on the average value of the J first differences, and the maximum fluctuation range of the values ​​in the region of interest can be determined based on the average value of the point cloud contrast of each point cloud block. If the above fluctuation range is small, it means that the changes in different areas within each point cloud block and different areas within the region of interest are smooth, indicating that the distribution state of the reflectivity is as expected, and it can be determined that the light receiving and light paths are correctly aligned.

[0092] Please refer to Figure 9 , Figure 9 Another method of determining the point cloud contrast of the region of interest provided by the embodiment of the present application is exemplified. Figure 9 As shown, the specific implementation process of step S640 includes the following steps S910 to S930:

[0093] Step S910: For each point cloud block, determine K first ratios, where the first ratio is the ratio of the second difference to the first sum, the second difference is the difference between the maximum and minimum reflectivity of a column of point cloud points, and the first sum is the sum of the maximum and minimum reflectivity of a column of point cloud points.

[0094] Step S920: Determine the point cloud contrast of each point cloud block according to the average value of the K first ratios.

[0095] Step S930 : obtaining the point cloud contrast of the region of interest according to the average value of the point cloud contrast of each point cloud block.

[0096] by Figure 8 For example, in each point cloud block, the difference between the maximum and minimum values ​​of the reflectivity of the point cloud points in each column determines a second difference, the sum of the maximum and minimum values ​​of the reflectivity of the point cloud points in each column determines a first sum, and the ratio of the second difference to the first sum determines the first ratio corresponding to each column. 8 columns can determine 8 first ratios. Calculate the average value of the 8 first ratios as the point cloud contrast of the corresponding point cloud block. Since there are T point cloud blocks, the point cloud contrast corresponding to the T point cloud blocks can be obtained. Calculate the average value of the T point cloud contrasts as the point cloud contrast of the area of ​​interest. It can be understood that this embodiment is explained by taking the example of obtaining the point cloud contrast of the area of ​​interest through the point cloud points of each column. In other embodiments, the point cloud contrast of the area of ​​interest can also be obtained through the point cloud points of each row. The specific implementation process is similar to the above embodiment. It is within the scope that can be easily understood by those skilled in the art and will not be repeated here.

[0097] In this embodiment, the maximum fluctuation range of the values ​​in each point cloud block can be determined based on the average value of the K first ratios, and the maximum fluctuation range of the values ​​in the region of interest can be determined based on the average value of the point cloud contrast of each point cloud block. If the above fluctuation range is small, it means that the changes in different areas within each point cloud block and different areas within the region of interest are smooth, indicating that the distribution state of the reflectivity is as expected, and it can be determined that the light receiving and light paths are correctly aligned.

[0098] In some embodiments, as Figure 10 As shown, the specific implementation process of step S450 includes the following steps S1010 to S1020:

[0099] Step S1010: When the point cloud contrast of the region of interest is less than or equal to a second preset threshold, determining that the distribution state of the reflectivity of the second point cloud is a normal state.

[0100] Step S1020: When the point cloud contrast of the region of interest is greater than a second preset threshold, determining that the distribution state of the reflectivity of the second point cloud is an abnormal state.

[0101] Among them, the second preset threshold is a pre-set threshold, which can be set based on the actual application scenario, and the embodiments of the present application do not impose specific restrictions on this. In some embodiments, the second preset threshold is set to a smaller value. For example, the second preset threshold is set to any value in the range of 0.15±0.05, so that the point cloud contrast of the area of ​​interest can only be determined to be a smaller value, and the distribution state of the reflectivity of the second point cloud is determined to be normal, which is conducive to making the result of the aforementioned light receiving and light path alignment have higher reliability. It can be understood that when the distribution state of the reflectivity of the second point cloud is determined to be normal, it means that the changes in different areas within each point cloud block and different areas within the area of ​​interest are smooth, and the distribution state of the reflectivity is in line with expectations. Figure 1 The target positioning position obtained in the manner shown can align the light-emitting and light-receiving paths to a high degree.

[0102] In some embodiments, when the distribution state of the reflectivity of the second point cloud is determined to be abnormal, an alarm or interception may be performed.

[0103] Please refer to Figure 11 , Figure 11 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present application. Figure 11 As shown, the electronic device 1100 includes at least one processor 1101 and a memory 1102, wherein the memory 1102 can be built into the electronic device 1100 or externally located outside the electronic device 1100. The memory 1102 can also be a remotely set memory connected to the electronic device 1100 via a network.

[0104] The memory 1102 is a non-volatile computer-readable storage medium that can be used to store non-volatile software programs, non-volatile computer executable programs, and modules. The memory 1102 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal, etc. In addition, the memory 1102 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some embodiments, the memory 1102 may optionally include a memory remotely located relative to the processor 1101, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0105] The processor 1101 performs various functions of the terminal and processes data by running or executing software programs and / or modules stored in the memory 1102, and calling data stored in the memory 1102, thereby monitoring the terminal as a whole, for example, implementing the active alignment method of the light transmitting and receiving circuits described in any embodiment of the present application.

[0106] The processor 1101 may be one or more, Figure 11 In the figure, a processor 1101 is used as an example. The processor 1101 and the memory 1102 may be connected via a bus or other means. The processor 1101 may include a central processing unit (CPU), a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a controller, a field-programmable gate array (FPGA), etc. The processor 1101 may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors combined with a DSP core, or any other such configuration.

[0107] An embodiment of the present application further provides a non-volatile computer-readable storage medium, wherein the computer-readable storage medium stores computer-executable instructions, which are executed by one or more processors, for example, to execute the method steps of any one of the embodiments described above.

[0108] An embodiment of the present application also provides a computer program product, including a computer program stored on a non-volatile computer-readable storage medium, wherein the computer program includes program instructions. When the program instructions are executed by a computer, the computer executes the light-receiving and light-path alignment method in any of the above-mentioned method embodiments, for example, executes the method steps of any of the embodiments described above.

[0109] The above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0110] The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them. Based on the concept of the present application, the technical features in the above embodiments or different embodiments may be combined, and the steps may be implemented in any order. A person skilled in the art should understand that the technical solutions described in the above embodiments may be modified, or some of the technical features may be replaced by equivalents. However, such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for actively aligning a light-receiving and light-emitting circuit, characterized in that: Applied to a laser radar, the laser radar includes a transmitting plate, and the method includes: Obtaining N frames of first point clouds collected by the laser radar, where N is a positive integer, and the N frames of first point clouds correspond one-to-one to N first candidate positions of the transmitting plate, and the N first candidate positions are spaced apart along a first direction, and the first direction is perpendicular to the horizontal plane where the optical axis of the laser radar is located or perpendicular to the vertical plane where the optical axis is located; Selecting a first region, M second regions, and M third regions in the first point cloud, wherein the second regions, the first regions, and the third regions are arranged sequentially along the first direction, and M is a positive integer; Based on the reflectivity information of the first point cloud of N frames, a first evaluation function value curve of the first area, M second evaluation function curves of the second areas, and M third evaluation function value curves of the third areas are obtained, wherein the evaluation function value curves represent a corresponding relationship between evaluation function values ​​and the first candidate positions; Obtaining a target positioning position of the launch pad according to the first evaluation function value curve, M second evaluation function curves, and M third evaluation function value curves; Wherein, obtaining the target positioning position of the launch pad according to the first evaluation function value curve, the M second evaluation function curves, and the M third evaluation function value curves includes: Obtaining a first peak point of the first evaluation function value curve, M second peak points of the second evaluation function curve, and M third peak points of the third evaluation function value curve; The target positioning position is determined based on the first peak point, M second peak points, and M third peak points.

2. The method according to claim 1, characterized in that Obtaining the target positioning position according to the first peak point, the M second peak points, and the M third peak points includes: Determine a first positioning position among the N first candidate positions according to the first peak point; Determine M second positioning positions from N first candidate positions according to the M second peak points; Determine M third positioning positions from the N first candidate positions according to the M third peak points; Calculating an average of the coordinates of the M second positioning positions and the coordinates of the M third positioning positions to determine a fourth positioning position; The target positioning position is obtained according to the first positioning position and the fourth positioning position.

3. The method according to claim 2, characterized in that The obtaining of the target positioning position according to the first positioning position and the fourth positioning position includes: Obtaining a minimum value between an absolute value of a difference between the coordinates of the first positioning position and the coordinates of the fourth positioning position and a first preset threshold; The target positioning position is obtained based on the sum or difference between the coordinates of the first positioning position and the minimum value.

4. The method according to claim 1, wherein After obtaining the target positioning position of the launch plate, the method further includes: When the transmitting plate is located at the target positioning position, obtaining a second point cloud collected by the laser radar; Selecting a region of interest in the second point cloud, wherein the region of interest includes at least one point cloud block, and the point cloud block includes J rows and K columns of point cloud points, where J and K are both positive integers; Obtaining the maximum and minimum values ​​of the reflectivity of each row or column of point cloud points in each point cloud block; Obtaining the point cloud contrast of the region of interest according to the maximum value and the minimum value corresponding to each point cloud block; A distribution state of reflectivity of the second point cloud is determined according to the point cloud contrast of the region of interest.

5. The method according to claim 4, characterized in that Obtaining the point cloud contrast of the region of interest according to the maximum value and the minimum value corresponding to each point cloud block includes: In each of the point cloud blocks, J first difference values ​​are determined, wherein the first difference value is a difference between a maximum value and a minimum value of a reflectivity of a single row of point cloud points; determining a point cloud contrast of each of the point cloud blocks according to an average value of the J first differences; The point cloud contrast of the region of interest is obtained according to the average value of the point cloud contrast of each of the point cloud blocks.

6. The method according to claim 4, characterized in that Obtaining the point cloud contrast of the region of interest according to the maximum value and the minimum value corresponding to each point cloud block includes: For each of the point cloud blocks, K first ratios are determined, wherein the first ratio is a ratio of the second difference to the first sum, the second difference is a difference between a maximum value and a minimum value of reflectivity of a column of point cloud points, and the first sum is a sum of a maximum value and a minimum value of reflectivity of a column of point cloud points; determining a point cloud contrast of each of the point cloud blocks according to an average value of the K first ratios; The point cloud contrast of the region of interest is obtained according to the average value of the point cloud contrast of each of the point cloud blocks.

7. The method according to claim 4, characterized in that The distribution state includes a normal state and an abnormal state, and determining the distribution state of the reflectivity of the second point cloud according to the point cloud contrast of the region of interest includes: When the point cloud contrast of the region of interest is less than or equal to a second preset threshold, determining that the distribution state of the reflectivity of the second point cloud is a normal state; When the point cloud contrast of the region of interest is greater than the second preset threshold, it is determined that the distribution state of the reflectivity of the second point cloud is an abnormal state.

8. An electronic device, characterized in that: include: at least one processor and memory; The memory is coupled to the processor, and the memory is used to store instructions or programs. When the instructions or programs are executed by the at least one processor, the at least one processor executes the active alignment method for the light receiving and light circuit according to any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed, the method for actively aligning the light-emitting and light-receiving circuit according to any one of claims 1 to 7 is implemented.

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