Optical phased array lidar and scanning method for effective target edge profile

Abstract

The present application relates to the technical field of laser radar scanning, and more particularly to an optical phased array laser radar and a scanning method for an effective target edge profile, the scanning method comprising: S1: acquiring a grayscale image of a scene; S2: screening out effective targets and edge profiles, and extracting effective target edge profiles based on the effective targets and the edge profiles; S3: assigning different point cloud densities to the edge profiles according to the value coefficients of the effective targets, generating a point cloud coordinate set, and recording the scanning phase angles of the optical phased array corresponding to each point in the point cloud; S4: generating a control parameter set based on the scanning phase angles and through a pre-set scanning lookup table; and S5: controlling the optical phased array laser radar to sequentially scan each scanning region to obtain point cloud data. The present application has the advantages that the method reduces redundant data, reduces the complexity of subsequent data processing, and provides technical support for realizing optical phased array laser radar scanning imaging with higher performance and energy efficiency.

Description

Technical Field

[0001] This invention relates to the field of lidar scanning technology, and in particular to an optical phased array lidar and a method for scanning the effective target edge contour. Background Technology

[0002] Optical phased array (OPA) is a beam pointing technology that dynamically controls the direction, shape, and intensity of a beam by manipulating its phase. OPA lidar, with an OPA chip at its core, integrates laser ranging and imaging technologies. Its phase control primarily relies on two modulation methods: electro-optic and thermo-optic. Electro-optic modulation changes the carrier concentration and refractive index by applying a voltage to the PN junction of the waveguide; thermo-optic modulation achieves phase control by adjusting the temperature through a driving voltage.

[0003] In two-dimensional scanning, the OPA lidar controls the lateral scanning phase angle by driving voltage and simultaneously changes the laser wavelength to achieve longitudinal scanning, thereby covering the entire two-dimensional scene.

[0004] However, existing OPA LiDAR systems require additional photoelectric detection equipment such as cameras to identify ROIs (Regions of Interest). This limits scanning speed, with the writing and configuration speeds of control signals and voltage setup forming the main bottlenecks. Consequently, the frame rate during global scanning is too low to meet the demands of high-speed 3D point cloud acquisition. Furthermore, in practical applications (such as automotive radar), indiscriminate global scanning of low-value areas like the sky and roads not only generates a large amount of redundant data and wastes hardware resources but also further restricts the improvement of detection efficiency and frame rate. Summary of the Invention

[0005] Based on this, this invention proposes an optical phased array lidar and a scanning method for the effective target edge contour. The method uses an internal area array photodetector to image the scene, identify effective targets, and extract edge contours. The autonomously guided OPA lidar then scans based on these effective target edge contours. This improves the detection speed of the optical phased array lidar while reducing hardware resource consumption, effectively eliminating redundant data, and fundamentally reducing the hardware complexity of subsequent data output and processing modules.

[0006] To achieve the above objectives, the technical solution of this invention is implemented as follows: An optical phased array lidar includes: a laser for emitting a laser beam to scan objects in a scene; an optical phased array for controlling the laser beam through phase control to change the direction and shape of the laser beam; a planar photodetector for acquiring a two-dimensional grayscale image of the scene; an image processing module for performing target recognition and edge contour recognition on the two-dimensional grayscale image to obtain a set of point cloud coordinates of the effective target edge and the effective target edge contour of the scanning area; a data processing module for mapping the coordinates of each point in the point cloud coordinate set to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to a pre-set scan lookup table, generating a set of control parameters consisting of the driving voltage value and the emission wavelength value; and a control module for controlling the optical phased array lidar to scan the scanning area according to the set of control parameters to obtain point cloud data.

[0007] A scanning method based on the effective target edge contour, implemented using the aforementioned optical phased array lidar, includes the following steps:

[0008] S1: Obtain a 2D grayscale image of the scene.

[0009] S2: Perform target recognition and edge contour recognition on the two-dimensional grayscale image. Through the target recognition algorithm, combined with the value coefficient of the target, select the effective targets. At the same time, use the edge contour recognition algorithm to extract and select the edge contours of all targets based on the grayscale difference of the image. Based on the effective targets and edge contours, obtain the edge contours of the effective targets.

[0010] S3: Assign different point cloud densities to the scanning area of ​​the edge contour of the effective target according to the value coefficient of each effective target, generate a set of point cloud coordinates, and record the optical phase array scanning phase angle corresponding to each point to be measured in the point cloud.

[0011] S4: Based on the scanning phase angle, the coordinates of each test point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scanning lookup table, thereby generating a set of control parameters.

[0012] S5: Based on the set of control parameters, control the optical phased array lidar to scan the scanning area of ​​the effective target edge contour in sequence, and obtain the point cloud data of the effective target edge contour.

[0013] Furthermore, step S2 includes: performing target identification and target analysis on the two-dimensional grayscale image to obtain target category and size information; determining the target value coefficient based on the target category and size information; and filtering targets whose value coefficients meet preset conditions as valid targets.

[0014] Furthermore, step S2 includes: performing digital image processing on the two-dimensional grayscale image, and extracting the edge contours of all targets based on the grayscale differences between pixels using an edge detection algorithm.

[0015] Furthermore, the grayscale differences between pixels are compared with a preset threshold, and points with grayscale differences greater than the threshold are extracted to form contours.

[0016] Furthermore, in step S3, the point cloud density is determined by the number of points to be measured per unit area; M is the number of points to be measured in the point cloud of the scanning area of ​​each effective target edge contour. i Calculated using the following formula:

[0017] ;

[0018] in, S is the value coefficient of the effective objective. i The area of ​​the scanned region of the effective target edge contour is denoted by k, where k is a scaling factor.

[0019] Furthermore, based on the scanning area of ​​the effective target edge contour and the number of test points, the test points are evenly distributed in the scanning area of ​​the edge contour in the form of a dot matrix, and the coordinates of each test point are determined to form a point cloud coordinate set. At the same time, the optical phased array scanning phase angle corresponding to each test point in the point cloud is recorded.

[0020] Furthermore, the pre-set scan lookup table in step S3 includes the following steps: driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase angle and the corresponding driving voltage value, and establishing a lateral scan lookup table; recording the longitudinal scan angle of each scan phase angle and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table; wherein, the lateral scan lookup table and the longitudinal scan lookup table are used to obtain the corresponding driving voltage and laser wavelength according to the coordinate mapping of the target point during the scanning process.

[0021] Furthermore, step S4 includes: the control module sets the emission wavelength of the laser and the driving voltage of the optical phased array according to the set of control parameters, and controls the optical phased array lidar to perform line-by-line scanning of all test points within the scanning area corresponding to the effective target edge contour.

[0022] This invention achieves the following beneficial effects: it utilizes a phased array photodetector to acquire a two-dimensional grayscale image of a scene, identifies effective targets and their edge contours, and then guides an optical phased array lidar (OPA) system for targeted scanning. This method leverages the inherent components of the OPA lidar system, eliminating the need for additional photodetector equipment such as cameras. By preprocessing the scene under test and combining the flexibility of the OPA system in steering control, it enables the scanning of potentially important targets.

[0023] The system quickly identifies "valid targets" and "edge contours" using 2D grayscale images, scanning only the coordinate regions of the valid target's edge contours. This significantly reduces the number of points that need to be measured, allowing for more frequent updates to key target information or the completion of a panoramic scan in a shorter timeframe.

[0024] This method optimizes resource allocation, concentrating limited detection capabilities on the scanning area of ​​key target contours, thereby significantly improving the detection speed of local scanning and the system's response speed to targets. Ultimately, it generates more distinctive and higher-quality 3D point clouds. Furthermore, this method reduces redundant data and lowers the complexity of subsequent data processing, providing technical support for achieving higher performance and energy efficiency in optical phased array lidar scanning imaging. Attached Figure Description

[0025] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0026] Figure 1 This is a flowchart of a scanning method based on the effective target edge contour provided in an embodiment of the present invention;

[0027] Figure 2 It is a point cloud density map of the edge contour of each effective target provided according to an embodiment of the present invention. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0029] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0030] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] The invention will now be described in detail with reference to specific embodiments.

[0033] like Figure 1 and Figure 2 As shown in the illustration, an optical phased array lidar provided by this invention includes: a laser, an optical phased array, a planar photodetector, an image processing module, a data processing module, and a control module. The laser emits a laser beam to scan objects in a scene. The optical phased array controls the laser beam through phase control to change its direction and shape. The planar photodetector acquires a two-dimensional grayscale image of the scene. The image processing module performs target recognition and edge contour recognition on the two-dimensional grayscale image to obtain a set of point cloud coordinates for the effective target edges and the effective target edge contours of the scanned area. The data processing module maps the coordinates of each point in the point cloud coordinate set to the driving voltage value of the optical phased array and the emission wavelength value of the laser, generating a set of control parameters consisting of the driving voltage value and the emission wavelength value, according to a pre-set scan lookup table. The control module controls the optical phased array lidar to scan the scanned area according to the control parameter set to obtain point cloud data.

[0034] A scanning method based on the effective target edge contour, implemented using the aforementioned optical phased array lidar, includes the following steps:

[0035] S1: The area array photodetector acquires a two-dimensional grayscale image of the scene.

[0036] S2: The image processing module performs target recognition and edge contour recognition on the 2D grayscale image. A deep learning-based target detection algorithm processes the 2D grayscale image and, combined with the target's value coefficient, filters out valid targets. Using an edge contour recognition algorithm, based on image grayscale differences, it extracts and filters out the target's edge contours. Based on valid targets and edge contours, it obtains the edge contours of the valid targets.

[0037] It should be noted that the execution order of step S2 is not limited: one can first use a deep learning-based target detection algorithm (combined with the target value coefficient) to screen out effective targets, and then extract edge contours for the effective targets; another can first use an edge contour recognition algorithm based on grayscale differences to extract contours, and then perform target recognition and screening based on this; or both can be performed simultaneously.

[0038] Specifically, the image processing module first uses a deep learning object detection algorithm to identify and analyze objects in a 2D grayscale image, obtaining the object's category and size information, resulting in multiple objects T1, T2, ..., Tn (n is a positive integer). Based on the object's category and size, its corresponding value coefficients Value1, Value2, ..., Value... n By comparing the value coefficients of each objective with preset thresholds, objectives with value coefficients higher than the thresholds are selected as valid objectives TE1, TE2, ..., TE3. m (m is a positive integer). Next, an edge contour recognition algorithm is used to compare the grayscale differences between pixels with a preset threshold, and pixels with grayscale differences greater than the threshold are extracted to extract the edge contours of the target. The recognition results of the effective targets and edge contours are combined, and the original image is processed using a target detection function to obtain the effective targets TE1, TE2, ..., TE... m The edge contours correspond to the scanning regions R1, R2, ..., R in the OPA scanning field of view. m (m is a positive integer).

[0039] It should be noted that the value coefficient is usually set based on experience: pedestrians, vehicles, and close-range targets are assigned larger values, while road surfaces and distant targets are assigned smaller values. The preset threshold is an empirical parameter and needs to be flexibly adjusted according to the on-site scenario and detection accuracy requirements; no specific limitations are made here.

[0040] By rapidly identifying "valid targets" and "edge contours" using 2D grayscale images, further processing yields the scanning coordinates of the valid target edge contours. Ultimately, only the scanning area of ​​the valid target edge contours is scanned. This significantly reduces the number of points that need to be measured, allowing for more frequent updates to key target information within the same timeframe, or enabling a panoramic scan to be completed in a shorter time.

[0041] S3: Assign different point cloud densities to the scanning area of ​​the edge contour of the effective target according to the value coefficient of each effective target, generate a set of point cloud coordinates, and record the optical phase array scanning phase angle corresponding to each point to be measured in the point cloud.

[0042] Point cloud density is determined by the number of points to be measured per unit area; M is the number of points to be measured in the point cloud of the scanned area of ​​each effective target edge contour. i Calculated using the following formula:

[0043] ;

[0044] in, S is the value coefficient of the effective objective. i The area of ​​the scanned region representing the effective target edge contour is denoted by k, which is a scaling factor. It should be noted that k is usually set empirically, with a value ranging from 0 to 1.

[0045] Based on the effective target edge contour and the number of test points, the test points are evenly distributed within the effective target edge contour in the form of a dot matrix, and the coordinates of each test point are determined as (x1, y1), (x2, y2), ..., (x...). Mi y Mi This forms a set of point cloud coordinates, and simultaneously records the optical phased array scanning phase angle corresponding to each point to be measured.

[0046] Point cloud density is dynamically allocated based on the value coefficient of the effective targets. For high-value targets (such as pedestrians and vehicles), a higher point cloud density is assigned to obtain finer contours and surface details. For low-value targets, a lower density scan is used to save resources and significantly improve the quality of useful data.

[0047] S4: Based on the scanning phase angle, the coordinates of each test point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scanning lookup table, thereby generating a set of control parameters.

[0048] The pre-set scan lookup table includes the following steps: Driving the optical phased array lidar to scan within the global field of view, recording the lateral angle of each scan phase and the corresponding driving voltage value, and establishing a lateral scan lookup table. Recording the longitudinal angle of each scan phase and the corresponding laser emission wavelength value, and establishing a longitudinal scan lookup table. The lateral and longitudinal scan lookup tables are used during the scanning process to obtain the corresponding driving voltage and laser wavelength based on the coordinate mapping of the target point in the point cloud. Based on the coordinates of each point, the driving voltage is obtained from the lateral scan lookup table, and the laser wavelength is obtained from the longitudinal scan lookup table.

[0049] The coordinates of the points to be measured on the edge contour of each valid target are (x1, y1), (x2, y2), ..., (x Mi y Mi The control parameter set (V1, λ1), (V2, λ2), ..., (V2, λ2) corresponding to the driving voltage value and the emission wavelength value for each point is mapped through horizontal and vertical scan lookup tables. Mi , λ ri ), ri is the scan area R i The number of rows of the test points corresponds to ri scanning wavelengths.

[0050] S5: Based on the set of control parameters, control the optical phased array lidar to scan the scanning area of ​​each effective target edge contour in sequence, and obtain the point cloud data of the effective target edge contour.

[0051] The control module sets the emission wavelength of the laser and the driving voltage of the optical phased array according to the set of control parameters, and controls the optical phased array lidar to scan all the test points in the scanning area corresponding to the effective target edge contour line by line.

[0052] The emission wavelength of the laser is adjusted to λ1, where λ1 is the scanning wavelength corresponding to the first row of test points in the scanning area R1. Based on the driving voltage value obtained in step 4, the optical phased array is controlled to complete the scanning of the first row of test points in the scanning area R1.

[0053] Adjust the laser emission wavelength to λ2, ..., λ r1 , where r1 is the number of rows of test points in the scanning area R1, corresponding to r1 scanning wavelengths. Repeat the above process until all test points in the scanning area R1 are measured.

[0054] Steps S1 to S5 are executed iteratively to continuously generate 3D point cloud data of the effective target edge contour.

[0055] The scanning method based on the effective target edge contour of the present invention will be described below with reference to a specific embodiment:

[0056] like Figure 2 As shown, a target detection algorithm is used to process the original two-dimensional grayscale image acquired by the area array photodetector, identifying and extracting the effective targets TE1 and TE2. Simultaneously, the scanning regions R1 and R2 of the edge contours corresponding to the effective targets TE1 and TE2 are determined. The value coefficient of scanning region R1 is higher than that of scanning region R2.

[0057] The number of test points in scanning regions R1 and R2 are determined based on the value coefficients.

[0058] First, the laser wavelength is set to λ11. Under this wavelength, the optical phased array sequentially applies a set of driving voltages V11, V12, …, V1c1, each corresponding to a test point in the first row, to achieve sequential scanning of all test points in that row. Subsequently, for each subsequent row of the scanning area R1, the laser wavelength is sequentially switched to λ12, …, λ1r1, while the optical phased array continues to use the driving voltages V11, …, V1c1 matched to the first row. These are applied in the same order to complete the row scan. The row scan process is repeated once a new set of parameters is configured, until all test points in all rows within the scanning area R1 are measured.

[0059] After completing the scanning of scanning area R1, the scanning of scanning area R2 is then performed. At this time, the laser wavelengths are sequentially set to λ21, ..., λ2r2, and the optical phased array is synchronously switched to driving voltages V21, ..., V2c2 corresponding to the positions of each test point in scanning area R2. The driving voltage applied to the test points at each corresponding position in each row of scanning area R2 remains consistent. For each set of wavelength and voltage parameters, a complete row scan is performed until all test points within scanning area R2 have been measured.

[0060] Table 1. Correspondence between the test points in the scanning area R1 and the driving voltage and emission wavelength.

[0061]

[0062] As shown in Table 1, taking the scanning area R1 as an example, the specific scanning order is (x11, y11), (x12, y11), ..., (x1c1, y11); (x11, y12), (x12, y12), ..., (x1c1, y12); ...; (x11, y1r1), (x12, y1r1), ..., (x1c1, y1r1). Where (x11, y11) represents the coordinates of the point to be measured in the first row and first column of the scanning area R1 of the edge contour; (x12, y11) represents the coordinates of the point to be measured in the first row and second column of the scanning area R1 of the edge contour; ..., (x1c1, y11) represents the coordinates of the point to be measured in the first row and c1 column of the scanning area R1 of the edge contour; (x11, y12) represents the coordinates of the point to be measured in the second row and first column of the scanning area R1 of the edge contour; and (x12, y12) represents the coordinates of the point to be measured in the second row and first column of the scanning area R1 of the edge contour. The coordinates of the point to be measured in the 2nd row and 2nd column of the scanning area R1, ..., (x1c1, y12) are the coordinates of the point to be measured in the 2nd row and c1st column of the scanning area R1 of the edge contour; ...; (x11, y1r1) are the coordinates of the point to be measured in the r1th row and 1st column of the scanning area R1 of the edge contour, (x12, y1r1) are the coordinates of the point to be measured in the r1th row and 2nd column of the scanning area R1 of the edge contour, ..., (x1c1, y1r1) are the coordinates of the point to be measured in the r1th row and c1st column of the scanning area R1 of the edge contour.

[0063] Through the above process, the optical phased array lidar generates 3D point cloud data of the edge contours of all effective targets. After the scanning area of ​​the edge contours of all effective targets is completed, the system will cycle back to the initial step: the area array photodetector will acquire the 2D grayscale image of the scene again, and perform a new round of target recognition and adaptive scanning, thereby realizing the continuous updating of the 3D point cloud data of the scanning area of ​​the edge contours of effective targets.

[0064] In summary, the scanning method based on the effective target edge contour of the present invention utilizes a planar photodetector to acquire a two-dimensional grayscale image of the scene, and identifies the effective target and the scanning area of ​​the effective target edge contour from it, thereby guiding the optical phased array lidar to perform targeted scanning. This method utilizes the inherent components of the OPA lidar system, eliminating the need for additional photodetector equipment such as cameras. By preprocessing the scene under test and combining the flexibility of the OPA system in steering control, it achieves the scanning of potentially important targets.

[0065] By preprocessing the 2D grayscale image, the scanning area of ​​the effective target edge contour is identified. Leveraging the flexible steering advantage of the optical phased array, dense scanning of potentially important targets is performed, while sparse scanning or skipping of less important targets is conducted. This reduces redundant data and lowers the complexity of subsequent data processing.

[0066] This method optimizes resource allocation, concentrating limited detection capabilities on the scanning area, thereby significantly improving the detection speed of local scanning and the system's response speed to targets. Ultimately, it generates more salient and higher-quality 3D point clouds. Furthermore, this method reduces redundant data and lowers the complexity of subsequent data processing, providing technical support for achieving higher performance and energy efficiency in optical phased array lidar scanning imaging.

[0067] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An optical phased array lidar, characterized in that, include: A laser is used to emit a laser beam to scan objects in a scene. An optical phased array is used to control a laser beam through phase control, thereby changing the direction and shape of the laser beam; A planar photodetector is used to acquire a two-dimensional grayscale image of the scene. The image processing module is used to perform target recognition and edge contour recognition on the two-dimensional grayscale image to obtain the point cloud coordinate set of the scanned area of ​​the effective target edge and the effective target edge contour. The data processing module is used to map the coordinates of each point in the point cloud coordinate set to the driving voltage value of the optical phased array and the emission wavelength value of the laser according to the pre-set scanning lookup table, and generate a set of control parameters consisting of the driving voltage value and the emission wavelength value. The control module is used to control the optical phased array lidar to scan the scanning area according to the set of control parameters to obtain point cloud data.

2. A scanning method based on the effective target edge contour, implemented using the optical phased array lidar as described in claim 1, characterized in that, Includes the following steps: S1: Obtain a 2D grayscale image of the scene; S2: Perform target recognition and edge contour recognition on the two-dimensional grayscale image. Valid targets are selected by combining the target recognition algorithm with the target's value coefficient. At the same time, the edge contour recognition algorithm is used to extract and select the edge contours of all targets based on the image grayscale difference. Based on the valid targets and the edge contours, the edge contours of the valid targets are obtained. S3: Assign different point cloud densities to the scanning area of ​​the edge contour of the effective target according to the value coefficient of each effective target, generate a set of point cloud coordinates, and record the optical phased array scanning phase angle corresponding to each point to be measured in the point cloud. S4: Based on the scanning phase angle, the coordinates of each test point are mapped to the driving voltage value of the optical phased array and the emission wavelength value of the laser through a pre-set scanning lookup table, thereby generating a set of control parameters; S5: According to the set of control parameters, control the optical phased array lidar to scan the scanning area of ​​the effective target edge contour in sequence to obtain the point cloud data of the effective target edge contour.

3. The scanning method based on the effective target edge contour according to claim 2, characterized in that, Step S2 includes performing target recognition and target analysis on the two-dimensional grayscale image to obtain target category and size information; Based on the target's category and size information, determine the target's value coefficient; Targets whose value coefficients meet preset conditions are selected as valid targets.

4. The scanning method based on the effective target edge contour according to claim 3, characterized in that, Step S2 includes: performing digital image processing on the two-dimensional grayscale image, and extracting the edge contours of all targets based on the grayscale differences between pixels using an edge detection algorithm.

5. The scanning method based on the effective target edge contour according to claim 4, characterized in that, The grayscale difference between pixels is compared with a preset threshold, and points with a grayscale difference greater than the threshold are extracted to form a contour.

6. The scanning method based on the effective target edge contour according to claim 4, characterized in that, In step S3, the point cloud density is determined by the number of points to be measured per unit area; The number of test points M in the point cloud of the scanned area of ​​each effective target edge contour i Calculated using the following formula: ； in, S is the value coefficient of the effective target. i is the area of ​​the scanned region of the effective target edge contour, and k is a scaling factor.

7. The scanning method based on the effective target edge contour according to claim 6, characterized in that, Based on the scanning area of ​​the effective target edge contour and the number of test points, the test points are evenly distributed in the scanning area of ​​the edge contour in the form of a dot matrix, and the coordinates of each test point are determined to form a point cloud coordinate set. At the same time, the optical phased array scanning phase angle corresponding to each test point in the point cloud is recorded.

8. The scanning method based on the effective target edge contour according to claim 2, characterized in that, The pre-set scan lookup table in step S3 includes the following steps: The optical phased array lidar is driven to scan within the global field of view, and the lateral angle of each scanning phase angle and the corresponding driving voltage value are recorded to establish a lateral scan lookup table. Record the longitudinal scanning angle of each scanning phase angle and the corresponding laser emission wavelength value, and establish a longitudinal scanning lookup table; The horizontal scan lookup table and the vertical scan lookup table are used to obtain the corresponding driving voltage and laser wavelength based on the coordinate mapping of the target point during the scanning process.

9. The scanning method based on the effective target edge contour according to claim 7, characterized in that, Step S4 includes: The control module sets the emission wavelength of the laser and the driving voltage of the optical phased array according to the set of control parameters, and controls the optical phased array lidar to scan all the test points in the scanning area corresponding to the effective target edge contour line by line.

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