A data processing method and apparatus

Abstract

The application discloses a data processing method and device, and relates to the technical field of computers. A specific implementation of the method comprises the following steps: determining a maximum irradiation area of a laser beam and a position of an intersection formed by boundary lines of the maximum irradiation area; detecting, in an environmental map, an object located in the maximum irradiation area and closest to the position of the intersection along a direction in a set direction set, calculating a distance of the object to the position of the intersection to obtain a first distance set; calculating a shortest distance from the position of the intersection to the maximum irradiation area along the direction in the direction set to obtain a second distance set, and determining a threshold range in the corresponding direction; comparing distances in the first distance set with the threshold range corresponding to the same direction, and determining the validity of laser point data according to a comparison result and a set judgment basis. The implementation compensates for errors of pose data, guarantees the accuracy of validity determination, and realizes preprocessing of newly acquired laser radar data.

Description

Technical Field

[0001] The present invention relates to the field of computer technology, and in particular to a data processing method and device. Background Art

[0002] LiDAR-based pose estimation is a core issue in mobile robotics research. LiDAR emits a laser beam in a fixed direction, generating corresponding laser point data. Laser point data from multiple directions constitutes LiDAR data. This continuously acquired LiDAR data can be used to construct an environmental map and locate the LiDAR within that map.

[0003] Existing technologies typically use the estimated LiDAR position within a grid map and the laser beam emission angle corresponding to the current laser point data to calculate whether there are obstacles within a certain distance of the grid map at that emission angle. However, because LiDAR data needs to be continuously acquired, if the environment in which the current LiDAR data is collected changes compared to the environment in which the map was constructed (for example, if a person moves), some laser point data in a frame of LiDAR data may appear on obstacles already on the grid map, which can assist in positioning; while other laser point data may appear on obstacles outside the grid map, which is not conducive to positioning.

[0004] In the process of implementing the present invention, the inventors discovered that the prior art has at least the following problems:

[0005] Directly using lidar data obtained by laser beam scanning to construct raster maps and positioning has poor accuracy. Summary of the Invention

[0006] In view of this, an embodiment of the present invention provides a data processing method and device. For laser point data, the maximum irradiation area of ​​the corresponding laser beam and the intersection position formed by the boundary line of the area are first determined based on the posture parameters, and then the distance between the object in the environment map and the intersection position is calculated. Then, based on the distance and the determined threshold range, the validity of the laser point data is determined, the error of the posture data is compensated, the accuracy of the validity judgment is ensured, and the preprocessing of the newly acquired lidar data is realized.

[0007] To achieve the above objective, according to one aspect of an embodiment of the present invention, a data processing method is provided.

[0008] A data processing method according to an embodiment of the present invention includes: determining the maximum illumination area of ​​the laser beam and the intersection position formed by the boundary line of the maximum illumination area based on the estimated posture data of the laser radar in the environment map, the set posture parameters and the emission angle of the laser beam corresponding to the laser point data; wherein the posture parameters are used to compensate for the error of the posture data; detecting the object located in the maximum illumination area and closest to the intersection position in the environment map along the directions in the set direction set, calculating the distance from the object to the intersection position, and obtaining a first distance set; calculating the shortest distance from the intersection position to the maximum illumination area along the directions in the direction set, and obtaining a second distance set; determining the threshold range in the corresponding direction based on the measured distance, measurement accuracy and the second distance set in the laser point data; comparing the distance in the first distance set with the threshold range corresponding to the same direction, and judging the validity of the laser point data based on the comparison result and the set judgment basis.

[0009] Optionally, the posture data includes an estimated position and an estimated angle, and the posture parameters include position parameters and angle parameters; determining the maximum irradiation area of ​​the laser beam includes: determining the emission point position of the laser beam; wherein the emission point position is within a circle with the estimated position as the center and the position parameter as the radius, and the position parameter is used to compensate for the error of the estimated position; calculating the angle of the laser beam in the map coordinate system based on the estimated angle and the emission angle, and using the calculated angle as the first angle; determining the emission point angle of the laser beam based on the first angle and the angle parameter; wherein the angle parameter is used to compensate for the error of the estimated angle, the minimum value of the emission point angle is the difference between the first angle and the angle parameter, and the maximum value is the sum of the first angle and the angle parameter; compounding the emission point position and the emission point angle to obtain the maximum irradiation area of ​​the laser beam.

[0010] Optionally, the emission point position and the emission point angle are compounded to obtain the maximum irradiation area of ​​the laser beam, including: determining a corresponding angle figure based on the first angle and the angle parameter; wherein the angle bisector of the angle figure represents the laser beam; moving the angle figure on the circle, and finding two tangents tangent to the circle during the movement; wherein the direction of the laser beam is maintained at the emission angle during the movement, and the vertex of the angle figure is located on or outside the circle; the open area formed by the two tangents and the arc sandwiched by the tangents constitutes the maximum irradiation area of ​​the laser beam; wherein the central angle of the arc is less than 180°.

[0011] Optionally, determining the intersection position formed by the boundary line of the maximum illumination area includes: calculating the distance from the intersection of the boundary line to the center of the circle based on the geometric relationship between the boundary line and the circle and the posture parameters; calculating the first horizontal projection of the line segment formed by the intersection and the center of the circle and the second vertical projection based on the first angle and the distance; calculating the position of the intersection in the map coordinate system based on the estimated position, the first projection and the second projection to obtain the intersection position; wherein the horizontal coordinate of the intersection position is the difference between the horizontal coordinate in the estimated position and the first projection, and the vertical coordinate is the difference between the vertical coordinate in the estimated position and the second projection.

[0012] Optionally, the shortest distance from the intersection position to the maximum irradiation area is calculated along the directions in the direction set, including: calculating the third projection of the first line segment on the current direction of the direction set, and the fourth projection of the second line segment on the current direction; wherein the first line segment is the line segment formed by the intersection of the boundary line and the center of the circle, and the second line segment is the line segment formed by the intersection of the current vector and the arc and the center of the circle; the current vector takes the intersection position as the starting point and the direction is the current direction; the third projection and the fourth projection are subtracted to obtain the shortest distance from the intersection position to the maximum irradiation area.

[0013] Optionally, the method also includes: selecting a second angle within the angle range formed by the angle parameters of the posture parameters to obtain an angle set; summing the first angle and the second angle of the angle set respectively to obtain the direction set accordingly; wherein the first angle is the sum of the estimated angle in the posture data and the emission angle.

[0014] Optionally, along the directions in the set direction set, an object located in the maximum illumination area and closest to the intersection position is detected in the environmental map, including: taking the intersection position as the starting point and the elements of the direction set as the directions, and detecting in the environmental map an object located in the maximum illumination area and closest to the intersection position.

[0015] Optionally, the judgment basis is: the number of distances within the threshold range is a set number; wherein the set number is less than or equal to the number of directions in the direction set; and the validity of the laser point data is determined based on the comparison result and the set judgment basis, including: if the comparison result meets the judgment basis, determining that the laser point data is valid data; if the comparison result does not meet the judgment basis, determining that the laser point data is invalid data.

[0016] To achieve the above objective, according to another aspect of an embodiment of the present invention, a data processing device is provided.

[0017] A data processing device according to an embodiment of the present invention includes: a position determination module for determining the maximum illumination area of ​​the laser beam and the intersection position formed by the boundary lines of the maximum illumination area based on estimated laser radar posture data in an environment map, set posture parameters, and the emission angle of the laser beam corresponding to the laser point data; wherein the posture parameters are used to compensate for errors in the posture data; a detection calculation module for detecting objects located in the maximum illumination area and closest to the intersection position in the environment map along directions in a set direction set, calculating the distance from the object to the intersection position, and obtaining a first distance set; a threshold determination module for calculating the shortest distance from the intersection position to the maximum illumination area along directions in the direction set, obtaining a second distance set, and determining a threshold range in the corresponding direction based on the measured distance, measurement accuracy, and the second distance set in the laser point data; and a comparison and judgment module for comparing the distances in the first distance set with the threshold range corresponding to the same direction, and determining the validity of the laser point data based on the comparison result and a set judgment basis.

[0018] Optionally, the posture data includes an estimated position and an estimated angle, and the posture parameters include position parameters and angle parameters; the position determination module is also used to determine the emission point position of the laser beam; wherein the emission point position is within a circle with the estimated position as the center and the position parameter as the radius, and the position parameter is used to compensate for the error of the estimated position; based on the estimated angle and the emission angle, the angle of the laser beam in the map coordinate system is calculated, and the calculated angle is used as the first angle; based on the first angle and the angle parameter, the emission point angle of the laser beam is determined; wherein the angle parameter is used to compensate for the error of the estimated angle, the minimum value of the emission point angle is the difference between the first angle and the angle parameter, and the maximum value is the sum of the first angle and the angle parameter; the emission point position and the emission point angle are compounded to obtain the maximum irradiation area of ​​the laser beam.

[0019] Optionally, the position determination module is further used to determine a corresponding angle figure based on the first angle and the angle parameter; wherein the angle bisector of the angle figure represents the laser beam; the angle figure is moved on the circle, and two tangents tangent to the circle are found during the movement; wherein, the direction of the laser beam is maintained at the emission angle during the movement, and the vertex of the angle figure is located on or outside the circle; the open area formed by the two tangents and the arc sandwiched between the tangents constitutes the maximum irradiation area of ​​the laser beam; wherein the central angle of the arc is less than 180°.

[0020] Optionally, the position determination module is also used to calculate the distance from the intersection of the boundary line to the center of the circle based on the geometric relationship between the boundary line and the circle and the posture parameters; calculate the first horizontal projection of the line segment formed by the intersection and the center of the circle and the second vertical projection based on the first angle and the distance; calculate the position of the intersection in the map coordinate system based on the estimated position, the first projection and the second projection to obtain the intersection position; wherein the horizontal coordinate of the intersection position is the difference between the horizontal coordinate in the estimated position and the first projection, and the vertical coordinate is the difference between the vertical coordinate in the estimated position and the second projection.

[0021] Optionally, the threshold determination module is also used to calculate the third projection of the first line segment in the current direction of the direction set, and the fourth projection of the second line segment in the current direction; wherein, the first line segment is the line segment formed by the intersection of the boundary line and the center of the circle, and the second line segment is the line segment formed by the intersection of the current vector and the arc and the center of the circle; the current vector takes the intersection position as the starting point and the direction is the current direction; the third projection and the fourth projection are subtracted to obtain the shortest distance from the intersection position to the maximum irradiation area.

[0022] Optionally, the device also includes: a set construction module, used to select a second angle within the angle range constituted by the angle parameters of the posture parameters to obtain an angle set; summing the first angle and the second angle of the angle set respectively to obtain the direction set accordingly; wherein, the first angle is the sum of the estimated angle in the posture data and the emission angle.

[0023] Optionally, the detection calculation module is further configured to detect an object located in the maximum illumination area and closest to the intersection position in the environment map, taking the intersection position as a starting point and the elements of the direction set as directions.

[0024] Optionally, the judgment basis is: the number of distances within the threshold range is a set number; wherein the set number is less than or equal to the number of directions in the direction set; the comparison and judgment module is further used to determine that the laser point data is valid data if the comparison result meets the judgment basis; if the comparison result does not meet the judgment basis, determine that the laser point data is invalid data.

[0025] To achieve the above objective, according to another aspect of the embodiments of the present invention, an electronic device is provided.

[0026] An electronic device according to an embodiment of the present invention includes: one or more processors; a storage device for storing one or more programs, wherein when the one or more programs are executed by the one or more processors, the one or more processors implement a data processing method according to an embodiment of the present invention.

[0027] To achieve the above objective, according to another aspect of the embodiments of the present invention, a computer-readable medium is provided.

[0028] A computer-readable medium according to an embodiment of the present invention stores a computer program, which, when executed by a processor, implements a data processing method according to an embodiment of the present invention.

[0029] One embodiment of the above invention has the following advantages or beneficial effects: for laser point data, the maximum irradiation area of ​​the corresponding laser beam and the intersection position formed by the boundary line of the area are first determined based on the posture parameters, and then the distance between the object in the environment map and the intersection position is calculated, and then the validity of the laser point data is determined based on the distance and the determined threshold range, thereby compensating for the error of the posture data, ensuring the accuracy of the validity judgment, and realizing the preprocessing of the newly acquired lidar data.

[0030] Position and angle parameters are used to compensate for errors in the pose data. The maximum irradiation area of ​​the laser beam is then determined based on the error compensation results, further ensuring the accuracy of subsequent effectiveness judgments. By moving the angle graph corresponding to the emission point angle on the circle corresponding to the emission point position, the emission point position and emission point angle are combined, facilitating the determination of the maximum irradiation area of ​​the laser beam.

[0031] Based on the pose data, the environment map, and the maximum illumination area, the intersection of the boundary lines of the maximum illumination area is calculated. This takes into account the errors in the estimated pose data, facilitating the selection of valid laser point data. By calculating the shortest distance from the intersection point to the maximum illumination area in each direction, a second distance set is constructed, which then determines the threshold range for the corresponding direction, improving the accuracy of subsequent laser point data validity determinations.

[0032] Constructing a direction set based on angle parameters allows for subsequent object detection and calculation of the first and second distance sets along at least one direction within the direction set, improving the accuracy of determining the validity of laser point data and reducing misjudgments. Detection is performed using the intersection location as the starting point and the elements of the direction set as the direction. This reduces the number of detections and computing resource consumption while ensuring effective detection. By setting a judgment basis to determine the validity of laser point data, valid data can be retained based on different needs, offering high flexibility.

[0033] The further effects of the above-mentioned non-conventional optional manner will be described below in conjunction with specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The accompanying drawings are provided for a better understanding of the present invention and are not intended to limit the present invention.

[0035] Figure 1 is a schematic diagram of main steps of a data processing method according to an embodiment of the present invention;

[0036] Figure 2 is a schematic diagram of the main flow of a data processing method according to an embodiment of the present invention;

[0037] FIG3( a ) is a schematic diagram of position data uncertainty of a laser radar according to an embodiment of the present invention;

[0038] FIG3( b ) is a schematic diagram of uncertainty in attitude data of a laser radar according to an embodiment of the present invention;

[0039] Figure 4 2. It is a schematic diagram of composite uncertainty of the laser radar posture according to an embodiment of the present invention;

[0040] Figure 5 Schematic diagram of the maximum irradiation area of ​​the laser beam corresponding to the laser point data of an embodiment of the present invention;

[0041] Figure 6 2 is a schematic diagram of a process for determining the maximum irradiation area of ​​a laser beam according to an embodiment of the present invention;

[0042] Figure 7 is a schematic diagram of calculating the intersection position formed by the boundary lines of the maximum irradiation area according to an embodiment of the present invention;

[0043] Figure 8 Schematic diagram of the shortest distance from the intersection point to the maximum irradiation area in the current direction according to an embodiment of the present invention;

[0044] Figure 9 Schematic diagram of calculating the shortest distance in the current direction according to an embodiment of the present invention;

[0045] Figure 10 is a schematic diagram of main modules of a data processing device according to an embodiment of the present invention;

[0046] Figure 11 is an exemplary system architecture diagram in which embodiments of the present invention may be applied;

[0047] Figure 12 It is a schematic structural diagram of a computer device suitable for implementing an electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] The following description of exemplary embodiments of the present invention is made in conjunction with the accompanying drawings, in which various details of the embodiments of the present invention are included to facilitate understanding. These details should be considered as merely exemplary. Therefore, it should be appreciated by those skilled in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0049] The technical terms involved in the embodiments are explained below.

[0050] A grid map is a digital representation of a real environment. It breaks the environment down into a series of discrete grid cells, with each cell assigned a value representing the probability of being occupied. A grid map identifies obstacles in the environment by determining whether a cell is occupied.

[0051] Figure 1 is a schematic diagram of main steps of a data processing method according to an embodiment of the present invention.

[0052] like Figure 1 As shown, the data processing method of the embodiment of the present invention mainly includes the following steps:

[0053] Step S101: Based on the estimated LiDAR pose data in the environment map, the set pose parameters, and the laser beam emission angle corresponding to the laser point data, the maximum illumination area of ​​the laser beam and the intersection position formed by the boundary lines of the maximum illumination area are determined. The LiDAR emits a laser beam in a fixed direction to obtain corresponding laser point data. Laser point data from multiple directions constitutes the LiDAR data. The pose data of the current cycle can be estimated based on the LiDAR data of the current cycle, the LiDAR pose data estimated in the previous cycle, and the odometry information.

[0054] Because the estimated pose data may contain errors (i.e., uncertainties), and these errors accumulate over time, pose parameters are needed to compensate for the errors in the pose data to ensure the accuracy of subsequent validity determinations. In this embodiment, the pose data includes an estimated position and an estimated angle. Accordingly, the pose parameters include position parameters and angle parameters, which are used to compensate for errors in the estimated position and estimated angle, respectively.

[0055] After using the pose parameter compensation, the LiDAR is located in a circle with the estimated position as the center and the position parameter as the radius; the LiDAR's orientation is within the estimated angle ± the angle parameter. Combining the position compensation results with the angle compensation results, we can see that the LiDAR's pose can appear in Figure 4 Any vector of .

[0056] Based on the above conclusions, Figure 4The angle graph formed by the moving vectors on the circle (i.e., the graph in Figure 3(b)) is formed. During the movement, the emission angle of the laser beam must remain unchanged, and two tangent lines tangent to the circle must be found during the movement. The open area formed by these two tangent lines and the arc between them constitutes the maximum irradiation area of ​​the laser beam. Then, based on the geometric relationship between the boundary line of the maximum irradiation area and the circle, the pose data, the pose parameters, and the emission angle, the position of the intersection of the boundary lines in the map coordinate system can be calculated.

[0057] Step S102: Detect objects located in the maximum illumination area and closest to the intersection in the environment map along the directions in the set direction set, calculate the distances from the objects to the intersection, and obtain a first distance set. To reduce the computational complexity of the detection process, the direction set can be constructed by selecting at least one second angle within the angle range corresponding to the angle parameter, and summing the first angle and the second angle to obtain a direction set. The first angle is the sum of the estimated angle and the emission angle.

[0058] After constructing the direction set, the object closest to the intersection point can be detected in the environment map, starting from the intersection point and using the elements of the direction set as directions. The object's position in the map coordinate system is then calculated based on the measured distance contained in the laser point data (i.e., the distance between the lidar and the object). The distance between the object and the intersection point can then be calculated using the distance formula between two points.

[0059] Step S103: Calculate the shortest distance from the intersection position to the maximum irradiation area along the directions in the direction set to obtain a second distance set, and determine the threshold range in the corresponding direction based on the measured distance, measurement accuracy and the second distance set in the laser point data.

[0060] Based on the geometric relationship between the boundary line of the maximum illumination area and the circle, the pose data, pose parameters, and emission angle, the shortest distance from the intersection point to the maximum illumination area in the current direction can be calculated. The minimum value of the threshold range in the current direction is the measured distance + the shortest distance in that direction - the measurement accuracy, while the maximum value is the measured distance + the shortest distance in that direction + the measurement accuracy. Using this method, the shortest distance and threshold range corresponding to at least one direction in the direction set can be calculated.

[0061] Step S104: Compare the distances in the first distance set with a threshold range corresponding to the same direction, and determine the validity of the laser point data based on the comparison result and a set judgment criterion. In one embodiment, the judgment criterion is: the number of distances within the threshold range is a set number; wherein the set number must be less than or equal to the number of directions in the direction set.

[0062] The distances in the first distance set are compared with the threshold range corresponding to the same direction. If the comparison result satisfies the above judgment criteria, the laser point data is determined to be valid data; if the comparison result does not satisfy the above judgment criteria, the laser point data is determined to be invalid data. For the newly acquired LiDAR data, after processing through steps S101 to S104 above, the laser point data determined to be valid can be retained, and the laser point data determined to be invalid can be deleted, and the deleted LiDAR data can be used for positioning.

[0063] The above embodiment uses posture parameters to compensate for the error of posture data, ensures the accuracy of subsequent validity determination, and realizes the preprocessing of newly acquired lidar data.

[0064] Figure 2 FIG. 1 is a schematic diagram of the main flow of the data processing method according to an embodiment of the present invention. Figure 2 As shown, the data processing method of the embodiment of the present invention mainly includes the following steps:

[0065] Step S201: Obtain the laser radar data obtained by scanning the objects in the environment. The laser radar data includes the laser point data obtained by emitting a laser beam in a specified direction. A laser point data includes: the distance between the laser radar and the object, dist i and the corresponding laser beam emission angle α i Therefore, the lidar data can be expressed as: {dist i , α i}, i=1, 2, ..., M, where M is the number of emitted laser beams. For ease of processing, in the embodiment, one frame of laser radar data is acquired each time.

[0066] Step S202: Determine the maximum irradiation area of ​​the laser beam based on the estimated position data of the laser radar in the environment map, the set position parameters, and the emission angle of the laser beam corresponding to the current laser point data in the laser radar data. In a two-dimensional environment, the position data of the laser radar in the environment map can be represented by a triple (x, y, θ). Among them, (x, y) is the estimated position, which represents the position of the laser radar in the map coordinate system; θ is the estimated angle, which represents the orientation of the laser radar (i.e., the angle between the line connecting the position point of the laser radar in the map coordinate system and the coordinate origin and the X-axis of the map coordinate system).

[0067] It will be appreciated that this method presupposes that the environment map and estimated pose data are known. In one embodiment, the environment map can be a grid map. The LiDAR pose can be estimated from the pose estimated in the previous cycle and other information such as odometry. The specific pose estimation method is known in the art and will not be further described here.

[0068] As mentioned above, the LiDAR’s position data is estimated and therefore has uncertainty. This uncertainty is shown in Figures 3(a) and 3(b). The uncertainty of the estimated position indicates that the LiDAR is located within a circle with the estimated position as the center and the set position parameter R as the radius. The uncertainty of the estimated angle indicates that the LiDAR’s orientation is within the estimated angle ± the angle parameter within the range of Combining these two uncertainties, we can conclude that the position of the lidar can appear in Figure 4 Any vector of .

[0069] In the embodiment, the position parameter R and the angle parameter These are all empirical values. For example, if the position of the lidar estimated by SLAM (Simultaneous Localization and Mapping) or other similar algorithms is within a circle with a center of (1.0, 1.0) and a radius of 0.2 meters, and the estimated bearing is 100 rad ± 5 rad, then R = 0.2 meters.

[0070] Since each laser point data corresponds to a known, fixed-angle laser beam in the laser radar, combined with the estimated laser radar pose data (x, y, θ) in the environment map, the emission point pose of the laser beam corresponding to a laser point data can be defined as: (x, y, θ + α i ). Therefore, the uncertainty of the LiDAR attitude data is the uncertainty of the emission point position and emission point angle of the laser beam corresponding to the laser point data.

[0071] according to Figure 4 , the emission point position of the laser beam corresponding to a laser point data may appear at Figure 5 In the circle shown, the angle of the emission point may be located in the area between the left and right rays BM and BN, that is, The range that the laser beam may irradiate (i.e. the maximum irradiation area) is the shaded area in the figure. The specific determination process will be combined later. Figure 6 Provide detailed explanation.

[0072] Step S203: Calculate the intersection position formed by the boundary lines of the maximum irradiation area. Figure 5 As shown, the boundary line of the maximum irradiation area is the left and right rays BM and BN. The two boundary lines are tangent to the circle, and the intersection point formed is the intersection point B of the rays BM and BN. Figure 7 How to calculate the coordinates of the intersection point B is explained in detail.

[0073] It should be noted that XO mapY is the map coordinate system, X'OY' is the laser radar coordinate system, OF, O' map D is parallel to the X axis, OE and BC are parallel to the Y axis, the coordinates of point O in the map coordinate system are (x, y), and the coordinates of point B to be calculated are (O' map B, BC), that is (O' map B, DE). Depend on Figure 7 It can be seen that O map E=x,OE=y,OA=R, ∠OBD=θ+α i The specific calculation process is as follows:

[0074] (1) Since the boundary line BM is tangent to the circle O, the position parameter R and the angle parameter The distance OB from the intersection point B to the center of the circle O can be calculated. OB is expressed as follows:

[0075]

[0076] (2) According to the estimated angle θ and the emission angle α i and distance OB, calculate the first horizontal projection and the second vertical projection of line segment OB, and you can get BD and OD respectively. BD and OD are expressed as follows:

[0077]

[0078]

[0079] (3) Calculate the intersection position (O') based on the estimated position of the laser radar, the first projection and the second projection map B, DE). The horizontal coordinate of the intersection position is the difference between the horizontal coordinate in the estimated position and the first projection, and the vertical coordinate is the difference between the vertical coordinate in the estimated position and the second projection. Then O' map B and DE are expressed by the following formula:

[0080]

[0081]

[0082] It can be seen that the coordinates of point B are:

[0083] Step S204: Detect objects in the environment map that are located in the maximum illumination area and closest to the intersection point along the directions in the set direction set, calculate the distance between the detected objects and the intersection point, and obtain a first distance set. The corresponding angle range is N angles are selected within the angle range, and the selected angles are summed with the first angle to obtain a direction set.

[0084] This step can start with the intersection position and the elements of the direction set as directions, and detect the object in the environment map that is located in the maximum illumination area and closest to the intersection position. Assume that the nth angle value selected is ρ n , then θ+α i +ρ n The object closest to the intersection point is detected in the environment map. Where n = 1, 2, ..., N.

[0085] Step S205: Calculate the shortest distance from the intersection point to the maximum irradiation area along the direction in the direction set to obtain a second distance set, and determine the threshold range in the corresponding direction based on the measured distance, measurement accuracy, and the second distance set in the current laser point data. Figure 8 As shown, the current direction (i.e. θ+α i +ρ n direction), the shortest distance from the intersection to the maximum irradiation area is d n , then the second distance set can be expressed as {d1, d2, ..., d N}. Assume the measured distance dist in the current laser point data i , the measurement accuracy is ±δ, then the threshold range in the current direction is [dist i +d n -δ,dist i +d n +δ].

[0086] The following combination Figure 9 This section explains in detail how to calculate the shortest distance in the current direction. The specific calculation process is as follows:

[0087] (1) Calculate the third projection of the first line segment OB in the current direction and the fourth projection of the second line segment OG in the current direction. The first line segment is the line segment OB formed by the intersection point B of the boundary line and the center O of the circle, and the second line segment is the line segment OG formed by the intersection point G of the current vector and the arc and the center O of the circle. The current vector is a vector starting from the intersection point B and heading in the current direction.

[0088] The third and fourth projections are FB and FG. FB can be expressed as follows:

[0089] FB=OB·cosρ n

[0090] Formula 6 is derived from the Pythagorean theorem OG 2 =OF 2 +FG 2, and OF=OB·sinρ n , but

[0091]

[0092] (2) Subtract the third projection FB from the fourth projection FG to obtain the shortest distance d from the intersection B to the maximum irradiation area. n At this time, the shortest distance d n It can be expressed by the following formula:

[0093]

[0094] It should be noted that When it is a negative value, you need to calculate the absolute value and then use Formula 8 to solve for the shortest distance.

[0095] Step S206: Compare the distances in the first distance set with the threshold range corresponding to the same direction. For each direction in the direction set, both the first distance set and the threshold range have a unique value corresponding to it. In this embodiment, the distances in the first distance set corresponding to each direction are compared with the threshold range corresponding to that direction.

[0096] Step S207: Determine the validity of the current laser point data based on the comparison result and the set judgment criteria. The judgment criteria are: the number of distances within the threshold range is a set number; the set number is less than or equal to the number of directions N in the direction set. It is understood that if the judgment criteria is set to a value greater than 1 and less than or equal to N, some valid laser point data may be deemed invalid. Therefore, preferably, to retain all valid laser point data, the judgment criteria is set to: the number of distances within the threshold range is 1.

[0097] If the comparison result satisfies the above judgment criteria, the current laser point data is determined to be valid data; if the comparison result does not satisfy the above judgment criteria, the current laser point data is determined to be invalid data.

[0098] Step S208: Check whether all laser point data have been judged to be valid. If so, end this process; if not, proceed to step S209. This step is used to check whether all laser point data in a frame of laser radar data have been judged to be valid.

[0099] Step S209: The next laser point data is used as the current laser point data, and step S202 is executed. The next laser point data whose validity has not been determined is selected from the laser radar data as the current laser point data, and steps S202 to S209 are repeated until all laser point data are determined.

[0100] The data processing method of the present invention demonstrates that this embodiment constructs a direction set based on angle parameters, enabling subsequent object detection, calculation of a first distance set and a second distance set along at least one direction in the direction set, and determination of the validity of the laser point data. This improves the accuracy of determining the validity of the laser point data and reduces false positives. Furthermore, by setting a determination basis to determine the validity of the laser point data, valid data can be retained based on different needs, providing high flexibility.

[0101] Figure 6 FIG. 1 is a flow chart showing the determination process of the maximum irradiation area of ​​a laser beam according to an embodiment of the present invention. Figure 6 As shown, the process of determining the maximum irradiation area includes the following steps:

[0102] Step S601: Determine the emission point position of the laser beam, wherein the emission point position is within a circle with the estimated position (x, y) as the center and the position parameter R as the radius.

[0103] Step S602: Sum the estimated angle and the emission angle to obtain the angle of the laser beam in the map coordinate system, and use this angle as the first angle. First angle = θ + α i .

[0104] Step S603: Determine the emission point angle of the laser beam based on the first angle and the angle parameter. The minimum value of the emission point angle is the difference between the first angle and the angle parameter, and the maximum value is the sum of the first angle and the angle parameter. Therefore, the emission point angle can be expressed as

[0105] Step S604: The emission point position and the emission point angle are combined to obtain the maximum irradiation area of ​​the laser beam. This step first determines the corresponding angle pattern based on the first angle and the angle parameter. The angle pattern is then moved along the circle, and two tangent lines to the circle are found during this movement. The angle bisector of the angle pattern represents the laser beam. During this movement, the laser beam must maintain its direction at the emission angle, and the vertex of the angle pattern must be on or outside the circle.

[0106] The open area formed by the two tangent lines and the arc between them constitutes the maximum irradiation area of ​​the laser beam. The arc between the tangent lines refers to an arc with a central angle less than 180°.

[0107] In the above method, by moving the angle graph corresponding to the emission point angle on the circle corresponding to the emission point position, the emission point position and the emission point angle are combined, which facilitates the determination of the maximum irradiation area of ​​the laser beam.

[0108] Figure 10FIG. 1 is a schematic diagram of the main modules of a data processing device according to an embodiment of the present invention. Figure 10 As shown, the data processing device 1000 according to the embodiment of the present invention mainly includes:

[0109] The position determination module 1001 is used to determine the maximum irradiation area of ​​the laser beam and the intersection position formed by the boundary line of the maximum irradiation area based on the estimated posture data of the laser radar in the environment map, the set posture parameters and the emission angle of the laser beam corresponding to the laser point data.

[0110] Because the estimated pose data may contain errors (i.e., uncertainty), and these errors accumulate over time, pose parameters are needed to compensate for the errors in the pose data to ensure the accuracy of subsequent validity determinations. In this embodiment, the pose data includes an estimated position and an estimated angle, and accordingly, the pose parameters include position parameters and angle parameters, which are used to compensate for errors in the estimated position and estimated angle, respectively.

[0111] After using the pose parameter compensation, the LiDAR is located in a circle with the estimated position as the center and the position parameter as the radius; the LiDAR's orientation is within the estimated angle ± the angle parameter. Combining the position compensation results with the angle compensation results, we can see that the LiDAR's pose can appear in Figure 4 Any vector of .

[0112] Based on the above conclusions, Figure 4 The angle graph formed by the moving vector on the circle is generated. During the movement, the laser beam's emission angle must be maintained constant, and two tangent lines tangent to the circle must be found during the movement. The open area formed by these two tangent lines and the arc between them constitutes the maximum illumination area of ​​the laser beam. Then, based on the geometric relationship between the boundary line of the maximum illumination area and the circle, the pose data, pose parameters, and the emission angle, the position of the intersection of the boundary lines in the map coordinate system can be calculated.

[0113] The detection and calculation module 1002 is used to detect the object located in the maximum illumination area and closest to the intersection position in the environment map along the direction in the set direction set, calculate the distance from the object to the intersection position, and obtain a first distance set.

[0114] Starting from the intersection point and using the elements of the direction set as directions, the system detects the object closest to the intersection point in the maximum illumination area within the environment map. The system then calculates the object's position in the map coordinate system based on the measured distance (i.e., the distance between the lidar and the object) contained in the laser point data. The distance between the object and the intersection point can then be calculated using the distance formula between two points.

[0115] The threshold determination module 1003 is used to calculate the shortest distance from the intersection position to the maximum illumination area along the directions in the direction set to obtain a second distance set, and determine the threshold range in the corresponding direction based on the measured distance, measurement accuracy and the second distance set in the laser point data.

[0116] Based on the geometric relationship between the boundary line of the maximum illumination area and the circle, the pose data, pose parameters, and emission angle, the shortest distance from the intersection point to the maximum illumination area in the current direction can be calculated. The minimum value of the threshold range in the current direction is the measured distance + the shortest distance in that direction - the measurement accuracy, while the maximum value is the measured distance + the shortest distance in that direction + the measurement accuracy. Using this method, the shortest distance and threshold range corresponding to at least one direction in the direction set can be calculated.

[0117] Comparison and determination module 1004 is configured to compare the distances in the first distance set with a threshold range corresponding to the same direction, and determine the validity of the laser point data based on the comparison result and a predetermined determination criterion. In one embodiment, the determination criterion is: the number of distances within the threshold range is a predetermined number; wherein the predetermined number must be less than or equal to the number of directions in the direction set.

[0118] The distances in the first distance set are compared with the threshold range corresponding to the same direction. If the comparison result meets the above judgment criteria, the laser point data is determined to be valid data; if the comparison result does not meet the above judgment criteria, the laser point data is determined to be invalid data. Subsequently, the valid laser point data in the lidar data can be retained and the invalid laser point data can be deleted before the lidar positioning is performed again.

[0119] In addition, the data processing device 1000 ( Figure 10 (not shown) may further include: a set construction module. This module is configured to select a second angle within the angle range formed by the angle parameters of the pose parameters to obtain an angle set; and sum the first angle with the second angle of the angle set to obtain the direction set accordingly; wherein the first angle is the sum of the estimated angle in the pose data and the launch angle.

[0120] From the above description, it can be seen that for laser point data, the maximum irradiation area of ​​the corresponding laser beam and the intersection position formed by the boundary line of the area are first determined based on the posture parameters. Then, the distance between the object in the environment map and the intersection position is calculated. Then, based on the distance and the determined threshold range, the validity of the laser point data is determined, which compensates for the error of the posture data, ensures the accuracy of the validity judgment, and realizes the preprocessing of the newly acquired lidar data.

[0121] Figure 11An exemplary system architecture 1100 is shown to which the data processing method or data processing apparatus according to the embodiment of the present invention can be applied.

[0122] like Figure 11 As shown, system architecture 1100 may include a laser radar 1101, a network 1102, and a server 1103. Network 1102 is used to provide a medium for a communication link between the laser radar 1101 and the server 1103. A user can use the laser radar 1101 to interact with the server 1103 via the network 1102 to receive or send messages, etc.

[0123] Server 1103 may be a server that provides various services, such as a background management server that processes the laser radar data sent by the laser radar 1101. The background management server may determine the validity of each laser point data, filter the laser radar data based on the processing results (e.g., the validity determination results), and then locate the position of the laser radar based on the filtered data.

[0124] It should be noted that the data processing method provided in the embodiment of the present application is generally executed by the server 1103, and accordingly, the data processing device is generally set in the server 1103.

[0125] It should be understood that Figure 11 The number of laser radars, networks, and servers in the embodiment is only for illustration. Any number of laser radars, networks, and servers may be used depending on the implementation requirements.

[0126] According to an embodiment of the present invention, the present invention further provides an electronic device and a computer-readable medium.

[0127] The electronic device of the present invention includes: one or more processors; a storage device for storing one or more programs, and when the one or more programs are executed by the one or more processors, the one or more processors implement a data processing method of an embodiment of the present invention.

[0128] The computer-readable medium of the present invention stores a computer program thereon, and when the program is executed by a processor, a data processing method according to an embodiment of the present invention is implemented.

[0129] Reference below Figure 12 , which shows a structural diagram of a computer system 1200 suitable for implementing an electronic device according to an embodiment of the present invention. Figure 12 The electronic device shown is only an example and should not limit the functions and scope of use of the embodiments of the present invention.

[0130] like Figure 12As shown, the computer system 1200 includes a central processing unit (CPU) 1201, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 1202 or a program loaded from a storage unit 1208 into a random access memory (RAM) 1203. Various programs and data required for the operation of the computer system 1200 are also stored in the RAM 1203. The CPU 1201, the ROM 1202, and the RAM 1203 are connected to each other via a bus 1204. An input / output (I / O) interface 1205 is also connected to the bus 1204.

[0131] The following components are connected to the I / O interface 1205: an input section 1206 including a keyboard, a mouse, and the like; an output section 1207 including devices such as a cathode ray tube (CRT), a liquid crystal display (LCD), and speakers; a storage section 1208 including a hard disk; and a communication section 1209 including a network interface card such as a LAN card or a modem. The communication section 1209 performs communication processing via a network such as the Internet. A drive 1210 is also connected to the I / O interface 1205 as needed. Removable media 1211, such as a magnetic disk, an optical disk, a magneto-optical disk, or a semiconductor memory, is installed in the drive 1210 as needed, so that computer programs read therefrom can be installed into the storage section 1208 as needed.

[0132] In particular, according to embodiments disclosed herein, the processes described in the main step diagrams above can be implemented as computer software programs. For example, embodiments disclosed herein include a computer program product comprising a computer program carried on a computer-readable medium, the computer program comprising program code for executing the methods shown in the main step diagrams. In such embodiments, the computer program can be downloaded and installed from a network via the communication section 1209, and / or installed from a removable medium 1211. When the computer program is executed by the central processing unit (CPU) 1201, the above-described functions defined in the system of the present invention are executed.

[0133] It should be noted that the computer-readable medium described in the present invention can be a computer-readable signal medium or a computer-readable storage medium, or any combination thereof. A computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media can include, but are not limited to, an electrical connection having one or more conductors, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof. In the present invention, a computer-readable storage medium can be any tangible medium containing or storing a program that can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present invention, a computer-readable signal medium can include a data signal propagated in baseband or as part of a carrier wave, carrying computer-readable program code. This propagated data signal can take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium that can transmit, propagate, or transport a program for use by or in conjunction with an instruction execution system, apparatus, or device. Program code embodied on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wireline, optical fiber cable, RF, or any suitable combination thereof.

[0134] The flowcharts and block diagrams in the accompanying drawings illustrate the possible implementation architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present invention. In this regard, each box in the flowchart or block diagram can represent a module, program segment, or a part of code, and the above-mentioned module, program segment, or a part of code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in an order different from that marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flowchart, and the combination of boxes in the block diagram or flowchart, can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0135] The modules involved in the embodiments of the present invention may be implemented in software or in hardware. The modules described may also be provided in a processor. For example, they may be described as: a processor including a position determination module, a detection and calculation module, a threshold determination module, and a comparison and judgment module. The names of these modules do not, in some cases, constitute a limitation on the modules themselves. For example, the position determination module may also be described as "a module for determining the maximum irradiation area of ​​the laser beam and the intersection position formed by the boundary lines of the maximum irradiation area based on the estimated posture data of the laser radar in the environmental map, the set posture parameters, and the emission angle of the laser beam corresponding to the laser point data."

[0136] As another aspect, the present invention further provides a computer-readable medium, which may be included in the device described in the above embodiment; or may exist independently without being assembled into the device. The computer-readable medium carries one or more programs. When the one or more programs are executed by a device, the device includes: determining the maximum illumination area of ​​the laser beam and the intersection position formed by the boundary line of the maximum illumination area based on the estimated posture data of the laser radar in the environment map, the set posture parameters and the emission angle of the laser beam corresponding to the laser point data; wherein the posture parameters are used to compensate for the error of the posture data; detecting the object located in the maximum illumination area and closest to the intersection position in the environment map along the directions in the set direction set, calculating the distance from the object to the intersection position, and obtaining a first distance set; calculating the shortest distance from the intersection position to the maximum illumination area along the directions in the direction set, and obtaining a second distance set; determining the threshold range in the corresponding direction based on the measured distance, measurement accuracy and the second distance set in the laser point data; comparing the distance in the first distance set with the threshold range corresponding to the same direction, and determining the validity of the laser point data based on the comparison result and the set judgment basis.

[0137] According to the technical solution of an embodiment of the present invention, for laser point data, the maximum irradiation area of ​​the corresponding laser beam and the intersection position formed by the boundary line of the area are first determined based on the posture parameters, and then the distance between the object in the environment map and the intersection position is calculated. Then, based on the distance and the determined threshold range, the validity of the laser point data is determined, the error of the posture data is compensated, the accuracy of the validity judgment is guaranteed, and the preprocessing of the newly acquired lidar data is realized.

[0138] The above-mentioned product can execute the method provided by the embodiment of the present invention, and has the functional modules and beneficial effects corresponding to the execution method. For technical details not fully described in this embodiment, please refer to the method provided by the embodiment of the present invention.

[0139] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may occur depending on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A data processing method, characterized in that: include: Determining a maximum irradiation area of ​​the laser beam and a position of an intersection formed by boundary lines of the maximum irradiation area based on estimated laser radar pose data in an environment map, set pose parameters, and an emission angle of a laser beam corresponding to laser point data; wherein the pose parameters are used to compensate for errors in the pose data; Detecting an object located in the maximum illumination area and closest to the intersection position in the environment map along a direction in the set direction set, and calculating a distance from the object to the intersection position to obtain a first distance set; Calculating the shortest distance from the intersection position to the maximum illumination area along a direction in the direction set to obtain a second distance set, and determining a threshold range in the corresponding direction based on the measured distance and measurement accuracy in the laser point data and the second distance set; Comparing the distances in the first distance set with a threshold range corresponding to the same direction, and determining the validity of the laser point data based on the comparison result and a set judgment basis; The posture data includes an estimated position and an estimated angle, and the posture parameters include a position parameter and an angle parameter; and determining the maximum irradiation area of ​​the laser beam includes: Determining the emission point position of the laser beam; wherein a circle is drawn with the estimated position as the center and the position parameter as the radius, the emission point position is located within the circle, and the position parameter is used to compensate for the error of the estimated position; Calculating the angle of the laser beam in a map coordinate system according to the estimated angle and the emission angle, and using the calculated angle as a first angle; Determining an emission point angle of the laser beam based on the first angle and the angle parameter; wherein the angle parameter is used to compensate for an error in the estimated angle, and a minimum value of the emission point angle is a difference between the first angle and the angle parameter, and a maximum value is a sum of the first angle and the angle parameter; Determining a corresponding angle graph according to the first angle and the angle parameter; wherein the angle bisector of the angle graph represents the laser beam; Moving the angle graph on the circle and finding two tangent lines tangent to the circle during the movement; wherein the direction of the laser beam is maintained at the emission angle during the movement, and the vertex of the angle graph is located outside the circle; The open area formed by the two tangent lines and the arc sandwiched between the tangent lines constitutes the maximum irradiation area of ​​the laser beam; wherein the central angle of the arc is less than 180°.

2. The method according to claim 1, characterized in that Determining the intersection position formed by the boundary lines of the maximum irradiation area includes: Calculating the distance from the intersection of the boundary lines to the center of the circle according to the geometric relationship between the boundary lines and the circle and the posture parameters; Calculate, based on the first angle and the distance, a first horizontal projection of a line segment formed by the intersection point and the center of the circle, and a second vertical projection of the line segment; Based on the estimated position, the first projection and the second projection, the position of the intersection in the map coordinate system is calculated to obtain the intersection position; wherein the horizontal coordinate of the intersection position is the difference between the horizontal coordinate in the estimated position and the first projection, and the vertical coordinate is the difference between the vertical coordinate in the estimated position and the second projection.

3. The method according to claim 1, characterized in that Calculating the shortest distance from the intersection position to the maximum irradiation area along a direction in the direction set includes: Calculate a third projection of a first line segment on the current direction of the direction set, and a fourth projection of a second line segment on the current direction; wherein the first line segment is a line segment formed by the intersection of the boundary line and the center of the circle, and the second line segment is a line segment formed by the intersection of the current vector and the arc and the center of the circle; the current vector has the intersection point as its starting point and its direction is the current direction; The third projection is subtracted from the fourth projection to obtain the shortest distance from the intersection position to the maximum irradiated area.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: Selecting a second angle within the angle range formed by the angle parameters of the posture parameters to obtain an angle set; The first angle and the second angle of the angle set are summed respectively to obtain the direction set accordingly; wherein the first angle is the sum of the estimated angle in the posture data and the emission angle.

5. The method according to claim 4, characterized in that Detecting an object located in the maximum illumination area and closest to the intersection position in the environment map along a direction in the set direction set includes: Taking the intersection position as a starting point and the elements of the direction set as directions, an object located in the maximum illumination area and closest to the intersection position is detected in the environment map.

6. The method according to any one of claims 1 to 3, characterized in that The judgment basis is: the number of distances within the threshold range is a set number; wherein the set number is less than or equal to the number of directions in the direction set; The validity of the laser point data is determined based on the comparison result and the set judgment basis, including: If the comparison result satisfies the judgment criterion, the laser point data is determined to be valid data; If the comparison result does not meet the judgment criterion, the laser point data is determined to be invalid data.

7. A data processing device, characterized in that: include: a position determination module for determining the maximum irradiation area of ​​the laser beam and the intersection position formed by the boundary lines of the maximum irradiation area based on the estimated posture data of the laser radar in the environment map, the set posture parameters, and the emission angle of the laser beam corresponding to the laser point data; wherein the posture parameters are used to compensate for errors in the posture data; a detection and calculation module, configured to detect, in the environment map, an object located in the maximum illumination area and closest to the intersection position along a direction in a set direction set, and calculate a distance from the object to the intersection position to obtain a first distance set; a threshold determination module, configured to calculate the shortest distance from the intersection position to the maximum illumination area along a direction in the direction set to obtain a second distance set, and determine a threshold range in the corresponding direction based on the measured distance and measurement accuracy in the laser point data and the second distance set; a comparison and judgment module, configured to compare the distances in the first distance set with a threshold range corresponding to the same direction, and determine the validity of the laser point data based on the comparison result and a set judgment basis; The posture data includes an estimated position and an estimated angle, and the posture parameters include a position parameter and an angle parameter; the position determination module is further configured to: Determining the emission point position of the laser beam; wherein a circle is drawn with the estimated position as the center and the position parameter as the radius, the emission point position is located within the circle, and the position parameter is used to compensate for the error of the estimated position; Calculating the angle of the laser beam in a map coordinate system according to the estimated angle and the emission angle, and using the calculated angle as a first angle; Determining an emission point angle of the laser beam based on the first angle and the angle parameter; wherein the angle parameter is used to compensate for an error in the estimated angle, and a minimum value of the emission point angle is a difference between the first angle and the angle parameter, and a maximum value is a sum of the first angle and the angle parameter; Determining a corresponding angle graph according to the first angle and the angle parameter; wherein the angle bisector of the angle graph represents the laser beam; Moving the angle graph on the circle and finding two tangent lines tangent to the circle during the movement; wherein the direction of the laser beam is maintained at the emission angle during the movement, and the vertex of the angle graph is located outside the circle; The open area formed by the two tangent lines and the arc sandwiched between the tangent lines constitutes the maximum irradiation area of ​​the laser beam; wherein the central angle of the arc is less than 180°.

8. An electronic device, characterized in that: include: one or more processors; a storage device for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the method according to any one of claims 1 to 6.

9. A computer-readable medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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