Laser radar detection method and device, storage medium and laser radar

Abstract

The embodiment of the invention discloses a laser radar detection method and device, a storage medium and a laser radar. The method comprises the steps of obtaining point cloud data corresponding to an (i-1) th ground line and point cloud data corresponding to an (i-2) th ground line; i is an integer greater than or equal to 3; based on the point cloud data corresponding to the (i-1) th line of ground line and the point cloud data corresponding to the (i-2) th line of ground line, calculating a prediction height range of the ith line of ground line, detecting scanning points of the ith line of scanning line based on the prediction height range, determining a target point in the scanning points, and obtaining the ith line of ground according to the target point, and the distances between the (i-2) th ground line, the (i-1) th ground line and the ith ground line and the laser radar are sequentially from near to far. According to the embodiment of the invention, the ith ground line is obtained by selecting the fitting height of the ground point with higher credibility on the ith scanning line, so that the definition of the ith ground line is improved.

Description

Technical Field

[0001] The present application relates to the field of laser radar technology, and in particular to a laser radar detection method, device, storage medium and laser radar. Background Art

[0002] When LiDAR is applied to the technical fields of autonomous driving or assisted driving, detecting the road surface or ground is a crucial function of LiDAR. LiDAR uses laser scanning to obtain the shape of the road surface or ground. The ground detected by LiDAR through laser scanning is presented in the form of ground lines, that is, the ground detected by LiDAR is composed of ground lines. Therefore, the clarity and stability of the ground lines determine whether the LiDAR detects the ground accurately. Summary of the invention

[0003] The embodiment of the present application provides a laser radar detection method, device, computer storage medium and laser radar, which screens out the ground points with higher credibility on the i-th line of scanning line through the point cloud data corresponding to the i-1th ground line that is closer to the laser radar than the i-th ground line to be generated and the point cloud data corresponding to the i-2th ground line, so as to obtain the i-th ground line according to the fitting height of the ground point with higher credibility, thereby achieving the effect of improving the clarity of the i-th ground line. The technical solution is as follows:

[0004] In a first aspect, an embodiment of the present application provides a laser radar detection method, the method comprising:

[0005] Get the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line; i is an integer greater than or equal to 3;

[0006] Calculate the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line;

[0007] Detecting scanning points of the i-th scanning line based on the predicted height range, and determining a target point among the scanning points;

[0008] The i-th ground line is obtained according to the target point; the distances between the i-2-th ground line, the i-1-th ground line, the i-th ground line and the laser radar are respectively from near to far.

[0009] In a second aspect, an embodiment of the present application provides a detection device of a laser radar, the device comprising:

[0010] A data acquisition module, used to acquire point cloud data corresponding to the i-1th ground line and point cloud data corresponding to the i-2th ground line; i is an integer greater than or equal to 3;

[0011] A height calculation module, used for calculating the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1-th ground line and the point cloud data corresponding to the i-2-th ground line;

[0012] A data detection module, configured to detect scanning points of the i-th scanning line based on the predicted height range, and determine a target point among the scanning points;

[0013] A data generation module is used to obtain the i-th ground line according to the target point; the distances between the i-2th ground line, the i-1th ground line, the i-th ground line and the laser radar are respectively from near to far.

[0014] In a third aspect, an embodiment of the present application provides a computer storage medium, wherein the computer storage medium has a plurality of instructions, and the instructions are suitable for being loaded by a processor and executing the above-mentioned method steps.

[0015] In a fourth aspect, an embodiment of the present application provides an electronic device, which may include: a memory and a processor; wherein the memory stores a computer program, and the computer program is suitable for being loaded by the memory and executing the above-mentioned method steps.

[0016] The beneficial effects brought by the technical solution provided by the embodiment of the present application include at least:

[0017] In an embodiment of the present application, the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line are obtained, and based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line, the predicted height range of the i-th ground line is calculated, and the scanning point of the i-th scanning line is detected based on the predicted height range, and the target point in the scanning point is determined, and the i-th ground line is obtained according to the target point, and the distances between the i-2th ground line, the i-1th ground line, and the i-th ground line and the laser radar are respectively from near to far. The embodiment of the present application selects ground points with higher credibility from the i-th scanning line through the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line that are relatively close, so as to obtain the i-th ground line according to the fitting height of the ground point with higher credibility, thereby achieving the effect of improving the clarity of the i-th ground line, and also enhancing the stability of the i-th ground line. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0019] Figure 1 It is a scene schematic diagram of a laser radar detection method provided in an embodiment of the present application;

[0020] Figure 2 It is a flowchart of a laser radar detection method provided in an embodiment of the present application;

[0021] Figure 3 It is a flowchart of another laser radar detection method provided in an embodiment of the present application;

[0022] Figure 4 This is a flow chart of another laser radar detection method provided in an embodiment of the present application.

[0023] Figure 5 It is a structural schematic diagram of a laser radar detection device provided in an embodiment of the present application;

[0024] Figure 6 It is a structural schematic diagram of a laser radar provided in an embodiment of the present application. DETAILED DESCRIPTION

[0025] In order to make the purpose, features, and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0026] In the description of the present application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, "including" and "having" and any of their variations are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products or devices. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood in specific circumstances. In addition, in the description of the present application, unless otherwise specified, "multiple" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the associated objects before and after are an "or" relationship.

[0027] In the field of laser radar technology, the intensity of the reflected signal corresponding to the target scanned by the laser radar is related to the incident angle of the laser scanning to the target. The larger the incident angle, the weaker the reflected signal intensity. In related technologies, the laser radar is installed approximately parallel to the ground. The farther the ground is from the laser radar, the greater the incident angle of the incident light scanned by the laser radar to that part, then the attenuation of the light signal is greater, and the signal-to-noise ratio of the ground reflection signal is worse, which will cause the point cloud detected by the laser radar to have missing points or inaccurate ranging results. When identifying ground information from the laser radar point cloud, the ground line obtained is blurred, that is, the clarity is poor. So how to improve the clarity of the ground line detected by the laser radar is a technical problem that needs to be solved urgently.

[0028] The present application is described in detail below with reference to specific embodiments.

[0029] See also Figure 1 , which is a scene diagram of a laser radar detection method provided in an embodiment of the present application.

[0030] like Figure 1 As shown, Figure 1 (a) shows the beam distribution diagram of the micro-electromechanical system (MEMS) laser radar; Figure 1 Figure (b) shows a scanning trajectory output by the MEMS lidar.

[0031] Figure 1(a) shows the relative positions of the i-th ground line, the i-1th ground line, and the i-2th ground line on the ground. It can be seen that the distances between the i-2th ground line, the i-1th ground line, and the i-th ground line and the laser radar are from near to far. Where i can be an integer greater than or equal to 3. The farther the ground line is from the laser radar, the greater the incident angle of the corresponding incident laser, and the less clear the detected ground line is, such as serious defects and inability to distinguish the boundaries of the ground.

[0032] The detection method of the present application is applicable to any laser radar with any scanning order. A frame of point cloud data obtained by the laser radar detecting the entire field of view can be stored in a cache, from which the first and second ground lines closest to the laser radar are identified, and this is used as a basis for detecting farther scanning lines line by line. However, storing a frame of point cloud data of the laser radar in a cached manner occupies more storage resources. The detection of the present application is more suitable for laser radars that scan line by line, such as MEMS laser radars. Figure 1 (b) shows the scanning points on the i-th scanning line, the points on the i-1-th scanning line, the points on the i-2-th scanning line, and the points on the i-3-th scanning line. Figure 1 The first row of scanning points from top to bottom in (b) can represent the scanning points on the i-th scanning line. Figure 1 The second row of scanning points in (b) can represent the scanning points on the i-1th row of scanning line. Figure 1 The third row of scanning points in (b) can represent the scanning points on the i-2th row of scanning line. Figure 1 The first row of scanning points in (b) can represent the scanning points on the i-3th row of scanning line. Figure 1 The arrow direction in (b) indicates the scanning order of these scanning points. The incident laser of the laser radar is deflected by the scanning device and then directed into the field of view, and the field of view is scanned according to the scanning order, for example Figure 1 (b) shows that the scan starts from the lower left and goes up line by line. The MEMS laser radar scans from bottom to top line by line, and only needs to cache the point cloud data of the first two scan lines to detect the ground line of the current line, occupying less storage resources. The MEMS laser radar that scans line by line from top to bottom can also adopt the detection method of the present application, and needs to store a frame of point cloud data before performing detection.

[0033] In the embodiment of the present application, when i is 3, the i-2th ground line can be directly obtained by using the ground points on the i-2th scanning line identified by the radar according to the algorithm, and the i-1th ground line can be directly obtained by using the ground points on the i-1th scanning line identified by the radar according to the algorithm. Since the scanning points on the 1st and 2nd scanning lines are closer to the laser radar, the received echo signal quality is good, and accurate scanning point detection results can be obtained through sampling and calculation, and the points of the ground line can be accurately identified from the detection results of the entire row of scanning points. The i-th ground line needs to use the point cloud data corresponding to the i-2th ground line and the point cloud data corresponding to the i-1th ground line to perform a series of calculation processes, select the target point from the scanning points on the i-th scanning line, and then obtain it based on the target point.

[0034] Specifically, the embodiment of the present application obtains point cloud data corresponding to the i-1th ground line (i is an integer greater than or equal to 3) and the point cloud data corresponding to the i-2th ground line, calculates the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line, detects the scanning point of the i-th row of scanning lines based on the predicted height range, determines the target point in the scanning point, obtains the i-th ground line according to the target point, and the distances between the i-2th ground line, the i-1th ground line, the i-th ground line and the laser radar are, respectively, distances from near to far. The embodiment of the present application screens out more credible ground points on the i-th scanning line from the i-th row of scanning lines through the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line that are closer to the laser radar than the i-th ground line to be generated, and generates the i-th ground line according to the fitting heights of the more credible ground points, thereby achieving the effect of improving the clarity of the i-th ground line while also enhancing the stability of the i-th ground line.

[0035] In the following method embodiments, for the sake of convenience, only the laser radar is introduced as the executor of each step.

[0036] See also Figure 2 , is a flow chart of a laser radar detection method provided in an embodiment of the present application. Figure 2 As shown, the method of the embodiment of the present application may include the following steps:

[0037] S201, obtaining point cloud data corresponding to the i-1th ground line and point cloud data corresponding to the i-2th ground line.

[0038] It is easy to understand that i is an integer greater than or equal to 3.

[0039] The i-1th ground line refers to a ground line that is adjacent to the i-th ground line and closer to the laser radar than the i-th ground line. That is, the distance between the i-1th ground line and the laser radar is smaller than the distance between the i-th ground line and the laser radar.

[0040] The point cloud data corresponding to the i-1th ground line refers to the detection results of multiple scanning points corresponding to the i-1th ground line. A scanning point can be understood as a scanning point obtained by completing a detection each time the laser radar emits an incident laser and receives the corresponding echo laser; the laser radar continuously scans the field of view to obtain a series of scanning points arranged in a scanning order. The detection results of the scanning point may include but are not limited to the coordinates of the scanning point in the coordinate system with the laser radar as the origin, the height of the scanning point, the yaw angle of the scanning point, the pitch angle of the scanning point, the relative speed of the scanning point, and the distance of the scanning point relative to the origin. All scanning points obtained by the laser radar completing a complete scan of the field of view constitute a frame of point cloud data.

[0041] Among them, a three-dimensional coordinate system is established with the radar as the center O, the direction facing the radar is the positive direction of the x-axis, the vertical upward direction is the z-axis direction, and the y-axis direction perpendicular to the xoz plane. The yaw angle refers to the angle between the light and the xoz plane, and the pitch angle refers to the angle between the light and the xoy plane.

[0042] The i-2th ground line refers to a ground line that is adjacent to the i-1th ground line and is closer to the laser radar than the i-1th ground line. That is, the distance between the i-2th ground line and the laser radar is smaller than the distance between the i-1th ground line and the laser radar.

[0043] The point cloud data corresponding to the i-2nd ground line refers to the detection results of multiple scanning points corresponding to the i-2nd ground line. The scanning points here refer to the scanning points used to constitute the i-2nd ground line. The detection results here can also include but are not limited to the coordinates of the scanning points in the three-dimensional coordinate system with the laser radar as the origin, the height of the scanning points, the yaw angle of the scanning points, the pitch angle of the scanning points, the relative speed of the scanning points, and the distance of the scanning points relative to the origin.

[0044] In some embodiments, the i-1th ground line may be composed of some or all scanning points on the i-1th row of scanning lines, and the i-2th ground line may be composed of some or all scanning points on the i-2th row of scanning lines. When i is equal to 3, the i-2th ground line is the ground line closest to the laser radar, and the i-1th ground line is the ground line closest to the i-2th ground line. The point cloud data of the scanning points constituting the i-2th ground line and the point cloud data of the scanning points constituting the i-1th ground line can be identified by an algorithm. For example, when multiple continuous scanning points with constant height are identified by the algorithm, the scanning points can be verified by the reflectivity information of the scanning points. When i is greater than 3, the i-2th ground line and the i-1th ground line can be determined by the method of the embodiment of the present application. In the case where the scanning points constituting the two ground lines have been determined as mentioned above, the point cloud data of these scanning points can be directly obtained from the data of these scanning points previously stored by the laser radar.

[0045] S202, calculating the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1-th ground line and the point cloud data corresponding to the i-2-th ground line.

[0046] In some embodiments, the yaw angle of each scanning point on the i-1th ground line and the height of each scanning point can be obtained according to the point cloud data corresponding to the i-1th ground line, and the mth scanning point on the i-1th ground line can be recorded as S (i-1,m) , m is an integer greater than or equal to 1. The yaw angle of each scanning point on the i-2th ground line and the height of each scanning point can be determined based on the point cloud data corresponding to the i-2th ground line. The nth scanning point on the i-2th ground line can be recorded as S (i-2,n), n is an integer greater than or equal to 1. The scanning points of the i-1th ground line and the scanning points of the i-2th ground line can be traversed to obtain K groups of point pairs, where K is a positive integer. A group of point pairs can include corresponding first reference points and second reference points. The first reference point is the scanning point of the i-1th ground line, and the second reference point is the scanning point of the i-2th ground line. Each group of point pairs can be composed of a unique first reference point and a unique second reference point. In each group of point pairs, the first reference point and the second reference point have the same swing angle. The criterion for determining that the swing angles of the first reference point and the second reference point are the same can be that the absolute value of the difference between the swing angles of the first reference point and the second reference point is less than or equal to the determination threshold. Calculating the predicted height range of the i-th ground line can be understood as calculating the predicted height range of the ground points on the i-th ground line. For the scanning point of the i-th ground line, there can be a scanning point with the same swing angle as a certain group of point pairs, then the predicted height range of the scanning point can be calculated based on the heights of the first reference point and the second reference point constituting the group of point pairs. For the scanning point of the i-th ground line, there may be a scanning point whose yaw angle is different from that of any of the above-mentioned point pairs. In this case, the predicted height range of the scanning point can be calculated based on the predicted height range of the scanning point that is adjacent to the scanning point and has the same yaw angle as a certain point pair.

[0047] S203, detecting the scanning points of the i-th scanning line based on the predicted height range, and determining the target point among the scanning points.

[0048] It is easy to understand that the i-th scan line refers to the i-th scan line in a frame of point cloud data. When the scanning order of the laser radar is to scan line by line from bottom to top, in the frame of point cloud data, the i-th scan line is above the i-1-th scan line, and the i-1-th scan line is above the i-2-th scan line.

[0049] In some embodiments, each scanning point of the i-th scanning line may be detected according to the predicted height range of each scanning point to determine whether each scanning point is a ground point. When a scanning point is determined to be a ground point, the scanning point may be determined as a target point.

[0050] Specifically, each scanning point is detected according to the predicted height range of each scanning point to determine whether each scanning point is a ground point. The specific implementation method of this operation can be: the scanning point of the i-th ground line can be first recorded as Si,j; wherein j is a positive integer, and j is less than or equal to the total number of scanning points of the i-th row of scanning lines; then, the heights of multiple scanning points within a neighborhood window centered on the scanning point Si,j are obtained, and the heights of the multiple scanning points within the neighborhood window are compared with the predicted height range of the scanning point Si,j to determine whether the scanning point Si,j is a ground point.

[0051] If the preset length of the neighborhood window is 10, the detection window may include 10 consecutive scanning points, of which the sixth scanning point is the scanning point Si,j.

[0052] The heights of multiple scanning points in the neighborhood window are compared with the predicted height range of the scanning point Si,j to determine whether the scanning point Si,j is a ground point. It can be understood that if the predicted height range of the scanning point Si,j is the first height range, it is determined that within the neighborhood window of the scanning point Si,j, the number of scanning points whose heights are within the first height range reaches a preset number, and the height of the scanning point Si,j is also within the first height range, then it can be determined that the scanning point Si,j is a ground point.

[0053] S204: Obtain the i-th ground line according to the target point.

[0054] Specifically, the target point can be recorded as Si,q; wherein q is a positive integer, and q is less than or equal to the total number of target points in the i-th scan line. The target point Si,q can be fitted to obtain a fitting height, and the i-th ground line can be obtained based on the fitting height. The i-th ground line can be obtained based on the fitting height, which can be understood as connecting these target points Si,q according to the fitting height of the target point Si,q to obtain the i-th ground line.

[0055] In the embodiment of the present application, the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line are obtained, and the predicted height range of the i-th ground line is calculated based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line. The scanning point of the i-th row of scanning lines is detected based on the predicted height range, and the target point in the scanning point is determined. The i-th ground line is obtained according to the target point, and the distances between the i-2th ground line, the i-1th ground line, and the i-th ground line and the laser radar are respectively from near to far. Since the incident angle of the incident laser close to the laser radar is relatively large, the quality of the received echo signal is good, and accurate scanning point detection results can be obtained through sampling and calculation, and the points of the ground line can be accurately identified from the detection results of the entire row of scanning points. The embodiment of the present application selects target points from the scanning points on the i-th scanning line through the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line, which are closer to the laser radar, to fit these target points to obtain the fitting height of the target points, and obtain the i-th ground line according to the fitting height. That is, the embodiment of the present application selects the ground points with higher credibility on the i-th scanning line through the above method, and generates the i-th ground line according to the fitting height of the ground points with higher credibility, thereby achieving the effect of improving the clarity of the i-th ground line and enhancing the stability of the i-th ground line. Further, the point cloud data of the i-1th ground line and the point cloud data of the i-th ground line enhanced by the above method are used to calculate the predicted height range of the i+1th ground line, and the scanning points of the i+1th scanning line are detected. By analogy, the ground lines in a frame of point cloud data are all detected and enhanced. Just because the embodiment of the present application improves the clarity of the ground lines, the clarity of the ground lines that were not clear in the distance is also increased, and the farthest distance of the ground lines that can be stably detected is also expanded.

[0056] See also Figure 3 , is a flow chart of a laser radar detection method provided in an embodiment of the present application. Figure 3 As shown, the method of the embodiment of the present application may include the following steps:

[0057] S301, obtaining point cloud data corresponding to the i-1th ground line and point cloud data corresponding to the i-2th ground line.

[0058] Specifically, see Figure 2 The description of S201 in the illustrated embodiment will not be repeated here.

[0059] S302, traverse the scanning points of the i-1th ground line and the scanning points of the i-2th ground line to obtain K groups of point pairs.

[0060] Where K is a positive integer. A set of point pairs includes a corresponding first reference point and a second reference point, the first reference point is a scanning point of the i-1th ground line, the second reference point is a scanning point of the i-2th ground line, and the difference in the yaw angle between the first reference point and the second reference point is less than or equal to a threshold.

[0061] In an embodiment of the present application, the scanning points corresponding to the i-2th ground line and the scanning points corresponding to the i-1th ground line can be traversed to find K groups of point pairs with the same yaw angle. Each group of point pairs consists of a first reference point and a second reference point with the same yaw angle. The criterion for determining the same yaw angle is that the absolute value of the difference between the yaw angles of the first reference point and the second reference point is less than or equal to a threshold. Specifically, the process of finding K groups of point pairs can be: determining the first yaw angles corresponding to all scanning points on the i-2th ground line, and determining the second yaw angles corresponding to all scanning points on the i-1th ground line; for each first yaw angle, find out whether there is a second yaw angle with the same yaw angle, if there is, the scanning point corresponding to the first yaw angle and the scanning point corresponding to the second yaw angle with the same yaw angle are taken as a group of point pairs, so that multiple groups of point pairs can be determined. The scanning point from the i-1th ground line in each group of point pairs can be the first reference point, and the scanning point from the i-2th ground line in each group of point pairs can be the second reference point.

[0062] S303: Calculate a predicted height range of the first scanning point based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point.

[0063] Among them, among the scanning points of the i-th row of scanning lines, the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is less than or equal to the threshold are the first scanning points, and the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is greater than the threshold are the rest as the second scanning points.

[0064] The first scanning point is a scanning point selected from all scanning points on the i-th scanning line. Each first scanning point is selected according to different groups of point pairs.

[0065] Specifically, the height fluctuation values ​​of the heights of K first reference points in the K groups of point pairs and the gradient values ​​of the point pairs corresponding to the first scanning point can be obtained, and the predicted height range of the first scanning point can be calculated based on the height fluctuation values ​​and the gradient values.

[0066] The height fluctuation value can be calculated from the heights of the K first reference points in the K groups of point pairs. The calculation formula for the height fluctuation value can be:

[0067]

[0068] in,

[0069] Wherein, k represents the summation parameter, and the value of k ranges from 1 to K. K represents the total number of all first reference points, that is, the total number of point pairs. i-1,k Represents the height of the first reference point in the kth point pair corresponding to the first scanning point.

[0070] For the kth point pair corresponding to the first scanning point, the height of the first reference point and the height of the second reference point included in the kth point pair can calculate a gradient value. The calculation formula of the gradient value can be:

[0071]

[0072] Among them, h i-2,k represents the height of the second reference point in the kth point pair corresponding to the first scanning point; i-1,k and i-1,k They respectively represent the x-axis coordinate value and the y-axis coordinate value of the first reference point in the k-th point pair corresponding to the first scanning point in the three-dimensional coordinate system centered on the laser radar; i-2,k and i-2,k They respectively represent the x-axis coordinate value and the y-axis coordinate value of the second reference point in the kth point pair corresponding to the first scanning point in the three-dimensional coordinate system centered on the laser radar.

[0073] Based on the height fluctuation value and the gradient value, the predicted height range of the first scanning point is calculated. The implementation method of this operation can be: first, based on the K groups of point pairs, the first scanning point with the same deflection angle as that of each group of point pairs is selected from each scanning point on the i-th row of the scanning line; then, based on the height fluctuation value of the first reference point in each group of point pairs and the gradient value of each group of point pairs, the predicted height range of the first scanning point with the same deflection angle as that of the group of point pairs is calculated.

[0074] According to the K groups of point pairs, the first scanning point with the same deflection angle as each group of point pairs is selected from each scanning point on the i-th row of scanning lines. The implementation method of this operation can be: for each group of point pairs, find out whether there is a scanning point with the same deflection angle as it among each scanning point on the i-th row of scanning lines. If there is, the scanning point with the same deflection angle as it is used as the first scanning point corresponding to the group of point pairs. The judgment standard of the same deflection angle is that the absolute value of the deflection angle difference between the scanning point and the first reference point in the group of point pairs is less than or equal to the judgment threshold, or the absolute value of the deflection angle difference between the scanning point and the second reference point in the group of point pairs is less than or equal to the judgment threshold.

[0075] It should be noted that for some point pairs, there may not be a matching first scan point in the i-th scan line. For example, for a certain set of point pairs, the matching point just happens to be missing, so there is no matching first scan point. Therefore, the number of first scan points may be less than the number of point pairs K.

[0076] According to the height fluctuation value of the first reference point in each group of point pairs and the gradient value of each group of point pairs, the predicted height range of the first scanning point having the same swing angle as the group of point pairs is calculated. The implementation method of this operation can be: according to the height fluctuation value of the first reference point in each group of point pairs and the gradient value of each group of point pairs, the maximum height and the minimum height of the first scanning point having the same swing angle as each group of point pairs can be calculated, and the minimum height and the maximum height constitute the predicted height range of the first scanning point.

[0077] The maximum height is calculated as:

[0078]

[0079] Among them, p i-1,k represents the pitch angle of the first reference point in the kth point pair corresponding to the first scanning point, p i,k represents the pitch angle of the first scanning point having the same pitch angle as the first reference point in the kth point pair corresponding to the first scanning point; B represents a first preset parameter, which can be determined based on actual experience; G k represents the gradient value of each set of point pairs calculated above; Δh represents the height fluctuation value of the height of the first reference point in each set of point pairs calculated above.

[0080] The minimum height is calculated as:

[0081]

[0082] Among them, p i-1,k represents the pitch angle of the first reference point in the kth point pair corresponding to the first scanning point, p i,k represents the pitch angle of the first scanning point having the same pitch angle as the first reference point in the kth point pair corresponding to the first scanning point; A represents the second preset parameter, which can be determined based on actual experience; G k represents the gradient value of each set of point pairs calculated above; Δh represents the height fluctuation value of the height of the first reference point in each set of points calculated above.

[0083] S304: Calculate the predicted height range of the second scanning point based on the predicted height range of the first scanning point.

[0084] As can be seen from the above, the first scanning point is a point with the same yaw angle as a certain set of point pairs, and the first scanning point and the scanning points included in the corresponding set of point pairs have a corresponding relationship in space, such as being approximately located on the same xoz plane. Due to the continuity of the ground, the first scanning point is likely to be a ground point, and the predicted height range of the first scanning point can be calculated more accurately based on the gradient value of the point pair and the height fluctuation value of the first reference point.

[0085] However, the scanning points on the i-th row scanning line, in addition to the first scanning point having the same deflection angle as the point pair, also have a scanning point that cannot match the point pair, namely, the second scanning point.

[0086] Since the second scanning point is a scanning point that cannot be matched with the point pair, the predicted height range of the second scanning point cannot be calculated using the heights of the scanning points included in the point pair. In this case, the predicted height range of the second scanning point can be determined using the first scanning point adjacent to the second scanning point.

[0087] Specifically, at least two first scanning points adjacent to the second scanning point among the scanning points on the i-th row of scanning lines can be determined, and the predicted height range corresponding to the second scanning point can be calculated based on the predicted height ranges of the at least two first scanning points adjacent to the second scanning point.

[0088] Specifically, for each second scanning point, a linear fitting method or a cubic spline fitting method may be used to calculate the predicted height range of the second scanning point according to the predicted height ranges corresponding to at least two first scanning points adjacent to the second scanning point.

[0089] Here, taking the linear fitting method as an example, the calculation process of the predicted height range of the second scanning point is explained.

[0090] First, the process of determining at least two first scanning points adjacent to the second scanning point is described. For example, a second scanning point is the mth point on the i-th row scanning line. When a scanning point adjacent to the mth point and located before the mth point is determined to be the first scanning point, and a scanning point adjacent to the mth point and located after the mth point is also determined to be the first scanning point, the two first scanning points are determined to be the two first scanning points adjacent to the mth point. When it is determined that a scanning point adjacent to the mth point and located before and after the mth point is not the first scanning point, the two first scanning points located before the mth point and most adjacent and second adjacent to the mth point can be determined as the two first scanning points adjacent to the mth point, or the two first scanning points located after the mth point and most adjacent and second adjacent to the mth point can be determined as the two first scanning points adjacent to the mth point.

[0091] The method for determining the scanning points before the mth point and the scanning points after the mth point can be found in Figure 1Schematic diagram of the scanning order of scanning points shown in Figure (b). According to the scanning points shown in Figure (b), assuming that the fourth row is the fourth line from top to bottom, and the mth point is the fifth scanning point from left to right in the fourth row, then the first four scanning points from left to right in the fourth row are the scanning points before the mth point, and the first eight scanning points from right to left in the fourth row are the scanning points after the mth point. Assuming that the third row is the third row from top to bottom, and the mth point is the fifth scanning point from left to right in the third row, then the first eight scanning points from right to left in the third row are the scanning points before the mth point, and the first four scanning points from left to right in the third row are the scanning points after the mth point.

[0092] Then, the calculation process of the predicted height range of the second scanning point is described. Using the mth point listed above, the two first scanning points adjacent to the mth point determined above are recorded as the pth point and the qth point respectively. Then, the calculation formula for the minimum height of the mth point is:

[0093]

[0094] Among them, minh p Indicates the minimum height in the predicted height range of point p; minh q Indicates the minimum height in the predicted height range of the qth point.

[0095] The calculation formula for the maximum height of the mth point is:

[0096]

[0097] Among them, maxh p Indicates the maximum height in the predicted height range of point p; maxh q Indicates the maximum height in the predicted height range of the qth point.

[0098] The height range consisting of the minimum height and maximum height of the m-th point is the predicted height range of the m-th point.

[0099] According to the calculation process of the predicted height range of the mth point, the predicted height ranges of most second scanning points on the i-th scanning line can be calculated. However, for a few second scanning points that do not have at least two adjacent first scanning points around them, their predicted height ranges are not calculated.

[0100] S305 , detecting the scanning points of the i-th scanning line based on the predicted height range, and determining the target point Si,q among the scanning points.

[0101] In a feasible implementation, when performing the operation of detecting the scanning points of the i-th scanning line based on the predicted height range and determining the target point Si,q in the scanning points, it may be:

[0102] A1: Get the heights of multiple scanning points within the neighborhood window centered at the scanning point Si,j.

[0103] Wherein, j is a positive integer, and j is less than or equal to the total number of scanning points of the i-th scanning line.

[0104] Specifically, a neighborhood window can be constructed with the scanning point Si,j to obtain a preset number of adjacent scanning points adjacent to the scanning point Si,j. Furthermore, since the multiple scanning points in the neighborhood window are also scanning points on the i-th row scanning line, the height of the scanning point can be directly obtained from the point cloud data detected by the laser radar.

[0105] The preset number of adjacent scanning points adjacent to the scanning point Si,j may include: a preset number of scanning points located before the scanning point Si,j and adjacent to the scanning point Si,j, and a preset number of scanning points located after the scanning point Si,j and adjacent to the scanning point Si,j. Therefore, the scanning point Si,j may be taken as the center of the neighborhood window, the preset number of adjacent scanning points located before the scanning point Si,j may be taken as the first half of the neighborhood window, and the preset number of adjacent scanning points located after the scanning point Si,j may be taken as the second half of the neighborhood window. For example, the preset number may be 5, and the 5 scanning points located before the scanning point Si,j and adjacent to the scanning point Si,j, and the 5 scanning points located after the scanning point Si,j and adjacent to the scanning point Si,j may all be determined as adjacent scanning points. Then, a neighborhood window can be determined, which is composed of the scanning point Si,j as the center of the neighborhood window, the five adjacent scanning points before the scanning point Si,j as the first half of the neighborhood window, and the five adjacent scanning points after the scanning point Si,j as the second half of the neighborhood window.

[0106] A2: Compare the heights of multiple scanning points in the neighborhood window with the predicted height range of the scanning point Si,j to determine whether the scanning point Si,j is a ground point.

[0107] It is easy to understand that the ground point means that the coordinates of the scanning point represent the scanning point located on the ground.

[0108] Specifically, a method for determining that a scanning point Si,j is a ground point may be implemented as follows: when the height of the scanning point Si,j is within the predicted height range of the scanning point Si,j, and the number of scanning points within the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a first threshold, the scanning point is determined to be a ground point. That is, if the height of the scanning point Si,j is within its own predicted height range, and the number of scanning points within the neighborhood window whose heights are within the predicted height range is greater than a first threshold, then the scanning point may be determined to be a ground point. The scanning point within the neighborhood window refers to the scanning point within the neighborhood window corresponding to the scanning point Si,j. The first threshold may be a threshold set according to experience, such as 3.

[0109] When the height of the scanning point Si,j is within its own predicted height range, it means that the scanning point Si,j is likely to be a ground point. In order to verify that the scanning point Si,j is a ground point, the heights of the scanning points around the scanning point Si,j (i.e., multiple scanning points within a neighborhood window centered on the scanning point Si,j) can be detected to accurately determine that the scanning point Si,j is a ground point.

[0110] For example: Assume that the scanning points in a neighborhood window may include: point d, point e, point f, point g, point h, point i, point j, point k, point l, point m, and point n. Among them, the center of the above neighborhood window is point i, point i is the scanning point Si,j, and the remaining points are scanning points in the neighborhood window corresponding to point i. The height of point i is within the predicted height range of point i itself; the height of point g is within the predicted height range of point i, the height of point h is within the predicted height range of point i, the height of point j is within the predicted height range of point i, and the heights of the remaining points are not within the predicted height range of point i. Then it can be determined that in the above neighborhood window, the number of scanning points whose heights are within the predicted height range of point i is 3, and point i can be determined to be a ground point. Otherwise, the i-th point is not a ground point.

[0111] Another implementation method for determining that a scanning point Si,j is a ground point may be: when the height of the scanning point Si,j is not within the predicted height range of the scanning point Si,j, and the number of scanning points within the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a second threshold, the scanning point is determined to be a ground point. That is, if the height of the scanning point Si,j is not within its own predicted height range, and the number of scanning points within the neighborhood window whose heights are within the predicted height range is greater than the second threshold, then the scanning point Si,j may be determined to be a ground point. The scanning point within the neighborhood window refers to the scanning within the neighborhood window corresponding to the scanning point Si,j. The second threshold may be a threshold determined empirically, such as may be set to 8.

[0112] When the height of the scanning point Si,j is not within its own predicted height range, it means that the possibility that the scanning point Si,j is a ground point is small. To avoid misjudgment, the heights of the scanning points around the scanning point Si,j (i.e., multiple scanning points within the neighborhood window centered on the scanning point Si,j) can be detected. If the heights of most of the points around the scanning point Si,j are within the predicted height range of the scanning point Si,j, it means that the conclusion that the scanning point Si,j is less likely to be a ground point is incorrect, that is, the scanning point Si,j is actually a ground point, so as to achieve the effect of accurately determining that the scanning point Si,j is a ground point.

[0113] For example: Assume that the scanning points in a neighborhood window may include: d point, e point, f point, g point, h point, i point, j point, k point, l point, m point, and n point. Among them, the center of the above neighborhood window is point i, point i is the scanning point Si,j, and the other points are the scanning points in the neighborhood window corresponding to point i. The height of point i is not within the predicted height range of point i itself; the height of point e is within the predicted height range of point i, the height of point f is within the predicted height range of point i, the height of point g is within the predicted height range of point i, the height of point h is within the predicted height range of point i, the height of point j is within the predicted height range of point i, the height of point k is within the predicted height range of point i, the height of point l is within the predicted height range of point i, the height of point n is within the predicted height range of point i, and the heights of the remaining points are not within the predicted height range of point i. Then it can be determined that the number of detection points in the above neighborhood window whose heights are within the predicted height range of point i is 8, and point i can be determined to be a ground point. Otherwise, the i-th point is not a ground point.

[0114] A3: If the scanning point is a ground point, the scanning point is determined as the target point.

[0115] Specifically, when the scanning point is determined to be a ground point, the scanning point may be determined as a target point for obtaining the i-th ground line.

[0116] S306, fitting the target point Si,q to obtain a fitting height.

[0117] The target point can be recorded as Si,q, where q is a positive integer and q is less than or equal to the total number of target points in the i-th scan line.

[0118] Specifically, the heights of multiple target points within a neighborhood window centered on the target point Si,q are obtained, or the heights of multiple target points within a neighborhood window where the target point Si,q is located are obtained; linear fitting is performed based on the heights of the multiple target points within the neighborhood window to obtain the fitted height of the target point Si,q.

[0119] The heights of multiple target points in a neighborhood window centered on the target point Si,q are obtained. The implementation method of this operation can be: taking the target point Si,q as the center, obtaining a preset number of adjacent target points adjacent to the target point Si,q, and obtaining a neighborhood window centered on the target point Si,q based on the target point Si,q and the adjacent target points of the target point Si,q. The heights of the multiple target points in the neighborhood window can be directly obtained according to the laser radar algorithm.

[0120] Obtain the heights of multiple target points within the neighborhood window where the target point Si,q is located: This operation can be implemented by determining the target point Si,q, all target points before the target point Si,q, and all target points after the target point Si,q as all target points in the neighborhood window. The heights of the multiple target points in the neighborhood window can be directly obtained according to the laser radar algorithm.

[0121] Based on the heights of multiple target points in the neighborhood window, linear fitting is performed to obtain the fitting height of the target point Si,q. The implementation method of this operation can be: linear fitting is performed on the height of the target point Si,q using the least squares method. All target points in the neighborhood window can be stored in a point sequence according to the order of the target points Si,q on the i-th row scan line. In the fitting process, the sequence number of the target point Si,q in the sequence can be used as an independent variable, and the height of the target point Si,q can be used as a dependent variable to find a linear function relationship between the independent variable and the dependent variable. The function value corresponding to the independent variable (i.e., the dependent variable value) can be used as the fitting height of the target point Si,q corresponding to the independent variable.

[0122] By performing linear fitting on the original height of the target point to obtain the fitted height of the target point, the height of the target point can be smoothed and de-noised.

[0123] S307, obtaining the i-th ground line based on the fitting height.

[0124] Specifically, these target points Si,q are connected according to their fitting heights to obtain the i-th ground line.

[0125] In an embodiment of the present application, the point pairs with the same yaw angle formed by the scanning points on the i-1th ground line and the scanning points on the i-2th ground line can not only calculate the height prediction range of the scanning points on the i-th scanning line that have the same yaw angle as the point pair, but also calculate the height prediction range of the scanning points on the i-th scanning line that do not match the point pair through the height prediction range of the scanning points on the i-th scanning line that have the same yaw angle as the point pair. Then, based on the predicted height range of all scanning points, ground points with higher credibility can be screened out from these scanning points. Finally, the fitting height obtained by fitting the height of the ground points with higher credibility is used to obtain the i-th ground line. Not only the clarity of the i-th ground line obtained based on the ground points with higher credibility is improved, but also the stability of the i-th ground line obtained by smoothing and denoising the height is improved.

[0126] See also Figure 4 , is a flow chart of a laser radar detection method provided in an embodiment of the present application. Figure 4 As shown, the method of the embodiment of the present application may include the following steps:

[0127] S401, obtaining point cloud data corresponding to the i-1th ground line and point cloud data corresponding to the i-2th ground line.

[0128] S402, traverse the scanning points of the i-1th ground line and the scanning points of the i-2th ground line to obtain K groups of point pairs.

[0129] S403, calculating a predicted height range of the first scanning point based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point.

[0130] S404: Calculate the predicted height range of the second scanning point based on the predicted height range of the first scanning point.

[0131] S405 , detecting the scanning points of the i-th scanning line based on the predicted height range, and determining the target point Si,q among the scanning points.

[0132] S406, fitting the target point Si,q to obtain a fitting height.

[0133] Specifically, S401-S406 can be found in Figure 3 The description of S301 - S306 in the illustrated embodiment will not be repeated here.

[0134] S407, determining a fitting height range of the scanning points of the i-th scanning line based on the fitting height of the target point Si,q.

[0135] As can be seen from the above, the target point is the scanning point on the i-th scanning line that is preliminarily judged to be a ground point. However, in addition to the target point, the scanning points on the i-th scanning line also include scanning points that are preliminarily judged not to be ground points, i.e., non-target points. The fitting height range of the target point can be calculated based on the fitting height of the target point. Further, the fitting height range of the non-target point can be calculated based on the fitting height range of the target point. Then, the fitting height range of all scanning points on the i-th scanning line can be obtained.

[0136] Specifically, based on the fitting height of the target point Si,q, the fitting height range of the scanning points of the i-th row of scanning lines is determined. The implementation method of this operation can be: obtaining the fitting heights of multiple target points in a neighborhood window centered on the target point Si,q, or obtaining the fitting heights of multiple target points in the neighborhood window where the target point Si,q is located; obtaining a fitting height fluctuation value based on the fitting heights of the multiple target points in the neighborhood window, determining the fitting height range of the target point Si,q based on the fitting height and the fitting height fluctuation value of the target point Si,q, and determining the fitting height range of the non-target point Si,p based on the fitting height range of the target point Si,q.

[0137] Among them, the non-target points are the scanning points other than the target points on the i-th scan line, p is a positive integer, q is a positive integer, the value of q is 1 to Q, Q represents the total number of target points, the value of p is 1 to P, P represents the total number of non-target points, and the sum of Q and P is the total number of scanning points on the i-th scan line.

[0138] The fitting heights of multiple target points in a neighborhood window with the target point Si,q as the center are obtained. The implementation method of this operation can be, taking the target point Si,q as the center, obtaining a preset number of adjacent target points adjacent to the target point Si,q, and obtaining a neighborhood window with the target point Si,q as the center based on the target point Si,q and the adjacent target points of the target point Si,q, and obtaining the fitting heights of multiple target points in the neighborhood window obtained by the above calculation.

[0139] The fitting heights of multiple target points in the neighborhood window where the target point Si,q is located are obtained. The implementation method of this operation can be to determine the target point Si,q, all target points before the target point Si,q, and all target points after the target point Si,q as all the target points in the neighborhood window, and the fitting heights of these target points obtained by the above calculation can be obtained.

[0140] The fitting height fluctuation value is obtained based on the fitting heights of multiple target points in the neighborhood window. Specifically, the calculation formula of the fitting height fluctuation value can be:

[0141]

[0142] Wherein, q represents the summation parameter, the value of q ranges from 1 to Q, and Q can represent the total number of target points; h q It can indicate the height of the target point; It can represent the fitted height of the target point.

[0143] Based on the fitting height and fitting height fluctuation value of the target point Si,q, the fitting height range of the target point Si,q is determined. The implementation method of this operation can be: according to the fitting height and fitting height fluctuation value of the target point Si,q, the maximum height in the fitting height range of the target point Si,q and the minimum height in the fitting height range of the target point Si,q are determined.

[0144] The calculation formula for the maximum height in the fitting height range of the target point Si,q can be:

[0145] The calculation formula for the minimum height in the fitting height range of the target point Si,q can be:

[0146]

[0147] Among them, A and B may be preset parameters, and A and B may be values ​​set according to experience in actual application process.

[0148] The fitting height obtained by smoothing and de-noising the height of the target point is used to estimate the new predicted height range of the target point (i.e., the fitting height range) and the new predicted height range of the non-target point (i.e., the fitting height range), that is, the predicted height range of the scanning point of the i-th row of scanning line is re-estimated to achieve the effect of correcting the initially estimated predicted height range of the target point, thereby improving the accuracy of the predicted height range of the scanning point of the i-th row of scanning line.

[0149] S408, taking the fitting height range of the scanning points of the i-th row of scanning lines as the predicted height range.

[0150] Specifically, for the scanning points of the i-th scanning line, it can be known from the above that the fitting height range of the scanning points of the i-th scanning line has been calculated, so the fitting height range of each scanning point can be used as the predicted height range of the scanning point itself.

[0151] S409, counting and determining whether the counted value is greater than a preset number of times.

[0152] Specifically, the count value is updated after being incremented by 1. The initial value of the count value is 1, and counting starts from 1. Each subsequent count can be a self-increment operation, that is, the first count is 1, the second count is 2, the third count is 3, and so on. Optionally, the preset number of times can be set to 3.

[0153] If yes, execute S410: obtain the i-th ground line based on the fitting height.

[0154] If not, the process returns to S405 : detecting the scanning points of the i-th scanning line based on the predicted height range, and determining the target point Si,q among the scanning points.

[0155] Specifically, return to execute S405: detect the scanning point of the i-th row of scanning line based on the predicted height range, and determine the target point Si,q in the scanning point. In this operation, at this time, the predicted height range is the fitting height range updated after re-estimation, so the target point Si,q in the scanning point can be re-selected according to the implementation method described in S405 based on the re-estimated height range. Further, execute S406 again, that is, calculate the fitting height of the re-selected target point Si,q according to the re-selected target point. Further, execute S407, S408, and S409 again in sequence, and return to execute S405, S406, S407, S408, and S409 again. In this way, the purpose of cyclically estimating the height range is achieved, and the target point Si,q is cyclically selected according to the height range estimated in each cycle, and the fitting height of the target point Si,q is cyclically calculated until the calculated value is greater than the preset number of times, the above-mentioned cycle process is stopped, and S410 is executed: the i-th ground line is obtained based on the fitting height.

[0156] Therefore, S410 can connect the fitting heights of the target points calculated in the last cycle to obtain the ith ground line. In this way, the ith ground line is a ground line with a high degree of credibility obtained through multiple cycles of detection, thereby improving the clarity of the ith ground line.

[0157] In this way, by repeatedly iterating to detect whether the target point is a ground point, the error caused by the predicted height range of the scanning point generated initially can be corrected, thereby further improving the credibility of the ground point finally detected, thereby further improving the clarity of the i-th ground line.

[0158] In the embodiment of the present application, the point pairs with the same yaw angle formed by the scanning points on the i-1th ground line and the scanning points on the i-2th ground line can not only calculate the height prediction range of the scanning points on the i-th scanning line that have the same yaw angle as the point pair, but also calculate the height prediction range of the scanning points on the i-th scanning line that do not match the point pair through the height prediction range of the scanning points on the i-th scanning line that have the same yaw angle as the point pair. Furthermore, the ground points with higher credibility can be screened out from these scanning points by iteratively calculating the fitting height range of each scanning point on the i-th scanning line. Thereby, the clarity of the i-th ground line obtained based on the ground points with higher credibility can be improved.

[0159] See also Figure 5 , is a schematic diagram of the structure of a laser radar detection device provided in an embodiment of the present application. The laser radar detection device 500 can be implemented as all or part of the laser radar through software, hardware, or a combination of both. The device 500 includes:

[0160] The data acquisition module 510 is used to acquire the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line; i is an integer greater than or equal to 3;

[0161] A height calculation module 520, configured to calculate a predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1-th ground line and the point cloud data corresponding to the i-2-th ground line;

[0162] A data detection module 530 is used to detect the scanning points of the i-th scanning line based on the predicted height range, and determine the target point in the scanning points;

[0163] The data generation module 540 is used to obtain the i-th ground line according to the target point; the distances between the i-2-th ground line, the i-1-th ground line, the i-th ground line and the laser radar are respectively from near to far.

[0164] Optionally, the height calculation module includes:

[0165] A first calculation unit is used to traverse the scanning points of the i-1th ground line and the scanning points of the i-2th ground line to obtain K groups of point pairs, where one group of point pairs includes a corresponding first reference point and a second reference point, the first reference point is the scanning point of the i-1th ground line, the second reference point is the scanning point of the i-2th ground line, and the difference between the yaw angles of the first reference point and the second reference point is less than or equal to a threshold value; wherein K is a positive integer;

[0166] A second calculation unit is used to calculate the predicted height range of the first scanning point based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point; wherein, among the scanning points of the i-th row of scanning lines, the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is less than or equal to the threshold are the first scanning points, the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is greater than the threshold are the rest of the scanning points are the second scanning points;

[0167] A third calculation unit calculates a predicted height range of a second scanning point based on the predicted height range of the first scanning point.

[0168] Optionally, the second computing unit includes:

[0169] A first calculation subunit is used to obtain height fluctuation values ​​of heights of K first reference points in the K groups of point pairs and gradient values ​​of point pairs corresponding to the first scanning point;

[0170] The second calculation subunit is used to calculate the predicted height range of the first scanning point based on the height fluctuation value and the gradient value.

[0171] Optionally, the third computing unit includes:

[0172] A third calculation subunit is used to determine at least two first scanning points adjacent to the second scanning point among the scanning points on the i-th row of scanning lines;

[0173] The fourth calculation subunit is used to calculate the predicted height range of the second scanning point based on the predicted height ranges of at least two first scanning points adjacent to the second scanning point.

[0174] Optionally, the data detection module includes:

[0175] A first detection unit is used to obtain the heights of multiple scanning points in a neighborhood window centered at the scanning point Si,j; wherein j is a positive integer, and j is less than or equal to the total number of scanning points of the i-th scanning line;

[0176] The second detection unit is used to compare the heights of the plurality of scanning points in the neighborhood window with the predicted height range of the scanning point Si,j, and determine whether the scanning point Si,j is a ground point;

[0177] The third detection unit is configured to determine the scanning point as a target point if the scanning point is a ground point.

[0178] Optionally, the second detection unit includes:

[0179] A first detection subunit, configured to determine that the scanning point is a ground point when the height of the scanning point Si,j is within the predicted height range of the scanning point Si,j and the number of scanning points in the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a first threshold;

[0180] The second detection subunit is used to determine that the scanning point is a ground point when the height of the scanning point Si,j is not within the predicted height range of the scanning point Si,j, and the number of scanning points in the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a second threshold.

[0181] Optionally, the data generation module includes:

[0182] A first data generating unit is used to fit the target point Si,q to obtain a fitting height; wherein q is a positive integer, and q is less than or equal to the total number of target points on the i-th scan line;

[0183] The second data generating unit is used to obtain the i-th ground line based on the fitting height.

[0184] Optionally, the data generation module also includes:

[0185] A third data generating unit, configured to determine a fitting height range of scanning points of the i-th scanning line based on the fitting height of the target point Si,q;

[0186] The fourth data generating unit is used to take the fitting height range of the scanning points of the i-th row of scanning lines as the predicted height range and count, return to execute the scanning point detection of the i-th row of scanning lines based on the predicted height range, and determine the target point among the scanning points until the count value is greater than a preset number of times.

[0187] Optionally, the third data generating unit is specifically used to:

[0188] Get the fitting heights of multiple target points within the neighborhood window centered on the target point Si,q;

[0189] Obtaining a fitting height fluctuation value based on the fitting heights of multiple target points within the neighborhood window;

[0190] Determine the fitting height range of the target point Si,q based on the fitting height and the fitting height fluctuation value of the target point Si,q;

[0191] Based on the fitting height range of the target point Si,q, the fitting height range of the non-target point Si,p is determined; wherein the non-target point is a scanning point other than the target point on the i-th scanning line, p is a positive integer, and the sum of q and p is the total number of scanning points on the i-th scanning line.

[0192] Optionally, the first data generating unit is specifically configured to:

[0193] Get the heights of multiple target points within the neighborhood window centered on the target point Si,q;

[0194] A linear fit is performed based on the heights of multiple target points within the neighborhood window to obtain the fitting height of the target point Si,q.

[0195] The present application also provides a laser radar, which stores at least one instruction, and the at least one instruction is loaded and executed by the processor as described above. Figure 2-Figure 4 The method steps of the embodiment shown in the figure can be found in the specific implementation process. Figure 2-Figure 4 The specific description of the illustrated embodiment will not be repeated here.

[0196] Please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of a laser radar provided in an embodiment of the present application. Figure 6As shown, the laser radar in the embodiment of the present application may include one or more of the following components: a chip 120, an input device 130, an output device 140, and a bus 150. The chip 120, the input device 130, and the output device 140 may be connected via the bus 150.

[0197] The chip 120 may include one or more processing cores. The chip 120 uses various interfaces and routes to connect the various parts of the entire laser radar, and executes various functions and processes data of the terminal 100 by running or executing instructions, programs, code sets or instruction sets stored in the chip 120, and calling data stored in the chip 120. Optionally, the chip 120 can be implemented in at least one hardware form of digital signal processing (DSP), field-programmable gate array (FPGA), and programmable logic array (PLA). The chip 120 can integrate one or a combination of a central processing unit (CPU), a modem, etc. Among them, the CPU mainly processes the operating system, user interface, and application programs. It can be understood that the above-mentioned modem may not be integrated into the chip 120, but may be implemented separately through a communication chip.

[0198] The chip 120 may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the chip 120 includes a non-transitory computer-readable storage medium. The chip 120 may be used to store instructions, programs, codes, code sets or instruction sets. The chip 120 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (such as a sound playback function, etc.), instructions for implementing the following various method embodiments, etc. The operating system may be an Android system, including a system deeply developed based on the Android system, an IOS system developed by Apple, including a system deeply developed based on the IOS system or other systems.

[0199] The input device 130 is used to receive input commands or data, and includes but is not limited to a keyboard, a mouse, a camera, a microphone, or a touch device. The output device 140 is used to output commands or data, and includes but is not limited to a display device and a speaker. In one example, the input device 130 and the output device 140 can be combined, and the input device 130 and the output device 140 are touch screen displays.

[0200] The touch display screen can be designed as a full screen, a curved screen or a special-shaped screen. The touch display screen can also be designed as a combination of a full screen and a curved screen, or a combination of a special-shaped screen and a curved screen, which is not limited in the embodiments of this specification.

[0201] In addition, those skilled in the art will understand that the structure of the laser radar shown in the above drawings does not constitute a limitation on the laser radar, and the laser radar may include more or fewer components than shown, or combine certain components, or arrange the components differently. For example, the laser radar also includes radio frequency circuits, input units, sensors, audio circuits, wireless fidelity (WiFi) modules, power supplies, Bluetooth modules and other components, which will not be described in detail here.

[0202] exist Figure 6 In the laser radar shown, the chip 120 can be used to call the program of the laser radar detection method stored in the chip 120, and specifically perform the following operations:

[0203] Get the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line; i is an integer greater than or equal to 3;

[0204] Calculate the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line;

[0205] Detecting scanning points of the i-th scanning line based on the predicted height range, and determining a target point among the scanning points;

[0206] The i-th ground line is obtained according to the target point; the distances between the i-2-th ground line, the i-1-th ground line, the i-th ground line and the laser radar are respectively from near to far.

[0207] In one embodiment, when the chip 120 calculates the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line, the following operations are specifically performed:

[0208] Traverse the scanning points of the i-1th ground line and the scanning points of the i-2th ground line to obtain K groups of point pairs, each group of point pairs includes a corresponding first reference point and a second reference point, the first reference point is the scanning point of the i-1th ground line, the second reference point is the scanning point of the i-2th ground line, and the difference in the yaw angle between the first reference point and the second reference point is less than or equal to a threshold; wherein K is a positive integer;

[0209] Based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point, the predicted height range of the first scanning point is calculated; wherein, among the scanning points of the i-th row of scanning lines, the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is less than or equal to the threshold are the first scanning points, and the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is greater than the threshold are the rest of the scanning points are the second scanning points;

[0210] Based on the predicted height range of the first scanning point, the predicted height range of the second scanning point is calculated.

[0211] In one embodiment, when the chip 120 calculates the predicted height range of the first scanning point based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point, the following operations are specifically performed:

[0212] Obtaining height fluctuation values ​​of the heights of K first reference points in the K groups of point pairs and gradient values ​​of the point pairs corresponding to the first scanning point;

[0213] Based on the height fluctuation value and the gradient value, a predicted height range of the first scanning point is calculated.

[0214] In one embodiment, when the chip 120 calculates the predicted height range of the second scanning point based on the predicted height range of the first scanning point, the following operations are specifically performed:

[0215] Determine at least two first scanning points adjacent to the second scanning point among the scanning points on the i-th row of the scanning line;

[0216] The predicted height range of the second scanning point is calculated based on the predicted height ranges of at least two first scanning points adjacent to the second scanning point.

[0217] In one embodiment, when the chip 120 detects the scanning points of the i-th scanning line based on the predicted height range and determines the target point in the scanning points, the chip 120 specifically performs the following operations:

[0218] Get the heights of multiple scanning points in a neighborhood window centered at the scanning point Si,j; where j is a positive integer, and j is less than or equal to the total number of scanning points in the i-th scanning line;

[0219] Compare the heights of multiple scanning points in the neighborhood window with the predicted height range of the scanning point Si,j to determine whether the scanning point Si,j is a ground point;

[0220] If the scanning point is a ground point, the scanning point is determined as a target point.

[0221] In one embodiment, when the chip 120 performs the comparison of the heights of the plurality of scanning points in the neighborhood window with the predicted height range of the scanning point Si,j and determines whether the scanning point Si,j is a ground point, the following operations are specifically performed:

[0222] When the height of the scanning point Si,j is within the predicted height range of the scanning point Si,j, and the number of scanning points in the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a first threshold, the scanning point is determined to be a ground point;

[0223] When the height of the scanning point Si,j is not within the predicted height range of the scanning point Si,j, and the number of scanning points in the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a second threshold, the scanning point is determined to be a ground point.

[0224] In one embodiment, when the chip 120 executes the step of obtaining the i-th ground line according to the target point, the following operations are specifically performed:

[0225] Fitting the target point Si,q to obtain a fitting height; wherein q is a positive integer, and q is less than or equal to the total number of target points on the i-th scan line;

[0226] Get the i-th ground line based on the fitted height.

[0227] In one embodiment, after performing fitting on the target points Si,q to obtain the fitting heights corresponding to the target points, the chip 120 further performs the following operations:

[0228] Determine the fitting height range of the scanning points of the i-th scanning line based on the fitting height of the target point Si,q;

[0229] The fitting height range of the scanning points of the i-th row of scanning lines is used as the predicted height range and counted, and the process of detecting the scanning points of the i-th row of scanning lines based on the predicted height range is returned to determine the target points among the scanning points until the count value is greater than a preset number of times.

[0230] In one embodiment, when the chip 120 determines the fitting height range of the scanning points of the i-th scanning line based on the fitting height of the target point Si,q, the chip 120 specifically performs the following operations:

[0231] Get the fitting heights of multiple target points within the neighborhood window centered on the target point Si,q;

[0232] Obtaining a fitting height fluctuation value based on the fitting heights of multiple target points within the neighborhood window;

[0233] Determine the fitting height range of the target point Si,q based on the fitting height and the fitting height fluctuation value of the target point Si,q;

[0234] Based on the fitting height range of the target point Si,q, the fitting height range of the non-target point Si,p is determined; wherein the non-target point is a scanning point other than the target point on the i-th scanning line, p is a positive integer, and the sum of q and p is the total number of scanning points on the i-th scanning line.

[0235] In one embodiment, when the chip 120 performs the fitting of the target point Si,q to obtain the fitting height, the following operations are specifically performed:

[0236] Get the heights of multiple target points within the neighborhood window centered on the target point Si,q;

[0237] A linear fit is performed based on the heights of multiple target points within the neighborhood window to obtain the fitting height of the target point Si,q.

[0238] An embodiment of the present application also provides a computer-readable storage medium, which stores at least one instruction, and the at least one instruction is used to be executed by a processor to implement the laser radar detection method as described in the above embodiments.

[0239] An embodiment of the present application also provides a computer program product, which stores at least one instruction, and the at least one instruction is loaded and executed by the processor to implement the laser radar detection method described in the above embodiments.

[0240] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented with hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0241] The above description is only an optional embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A laser radar detection method, characterized in that: The method comprises: Get the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line; i is an integer greater than or equal to 3; Calculate the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line; Detecting scanning points of the i-th scanning line based on the predicted height range, and determining a target point among the scanning points; The i-th ground line is obtained according to the target point; the distances between the i-2-th ground line, the i-1-th ground line, the i-th ground line and the laser radar are respectively from near to far.

2. The method according to claim 1, characterized in that The calculating the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1th ground line and the point cloud data corresponding to the i-2th ground line includes: Traverse the scanning points of the i-1th ground line and the scanning points of the i-2th ground line to obtain K groups of point pairs, each group of point pairs includes a corresponding first reference point and a second reference point, the first reference point is the scanning point of the i-1th ground line, the second reference point is the scanning point of the i-2th ground line, and the difference in the yaw angle between the first reference point and the second reference point is less than or equal to a threshold; wherein K is a positive integer; Based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point, the predicted height range of the first scanning point is calculated; wherein, among the scanning points of the i-th row of scanning lines, the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is less than or equal to the threshold are the first scanning points, and the scanning points whose yaw angle difference with the scanning points of the K groups of point pairs is greater than the threshold are the rest of the scanning points are the second scanning points; Based on the predicted height range of the first scanning point, the predicted height range of the second scanning point is calculated.

3. The method according to claim 2, characterized in that The calculating the predicted height range of the first scanning point based on the height of the first reference point and the height of the second reference point in the point pair corresponding to the first scanning point includes: Obtaining height fluctuation values ​​of the heights of K first reference points in the K groups of point pairs and gradient values ​​of the point pairs corresponding to the first scanning point; Based on the height fluctuation value and the gradient value, a predicted height range of the first scanning point is calculated.

4. The method according to claim 2, characterized in that: The calculating the predicted height range of the second scanning point based on the predicted height range of the first scanning point includes: Determine at least two first scanning points adjacent to the second scanning point among the scanning points on the i-th row of the scanning line; The predicted height range of the second scanning point is calculated based on the predicted height ranges of at least two first scanning points adjacent to the second scanning point.

5. The method according to claim 1, characterized in that The detecting the scanning points of the i-th scanning line based on the predicted height range and determining the target points among the scanning points comprises: Get the heights of multiple scanning points in a neighborhood window centered at the scanning point Si,j; where j is a positive integer, and j is less than or equal to the total number of scanning points in the i-th scanning line; Compare the heights of multiple scanning points in the neighborhood window with the predicted height range of the scanning point Si,j to determine whether the scanning point Si,j is a ground point; If the scanning point is a ground point, the scanning point is determined as a target point.

6. The method according to claim 5, characterized in that The step of respectively comparing the heights of the plurality of scanning points in the neighborhood window with the predicted height range of the scanning point Si,j to determine whether the scanning point Si,j is a ground point includes: When the height of the scanning point Si,j is within the predicted height range of the scanning point Si,j, and the number of scanning points in the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a first threshold, the scanning point is determined to be a ground point; When the height of the scanning point Si,j is not within the predicted height range of the scanning point Si,j, and the number of scanning points in the neighborhood window whose heights are within the predicted height range of the scanning point Si,j is greater than a second threshold, the scanning point is determined to be a ground point.

7. The method according to claim 1, characterized in that The obtaining the i-th ground line according to the target point comprises: Fitting the target point Si,q to obtain a fitting height; wherein q is a positive integer, and q is less than or equal to the total number of target points on the i-th scan line; Get the i-th ground line based on the fitted height.

8. The method according to claim 7, characterized in that After fitting the target point Si,q to obtain the fitting height, the method further includes: Determine the fitting height range of the scanning points of the i-th scanning line based on the fitting height of the target point Si,q; The fitting height range of the scanning points of the i-th row of scanning lines is used as the predicted height range and counted, and the process of detecting the scanning points of the i-th row of scanning lines based on the predicted height range is returned to determine the target points among the scanning points until the count value is greater than a preset number of times.

9. The method according to claim 8, characterized in that The step of determining the fitting height range of the scanning points of the i-th scanning line based on the fitting height of the target point Si,q includes: Get the fitting heights of multiple target points within the neighborhood window centered on the target point Si,q; Obtaining a fitting height fluctuation value based on the fitting heights of multiple target points within the neighborhood window; Determine the fitting height range of the target point Si,q based on the fitting height and the fitting height fluctuation value of the target point Si,q; Based on the fitting height range of the target point Si,q, the fitting height range of the non-target point Si,p is determined; wherein the non-target point is a scanning point on the i-th scanning line except the target point, p is a positive integer, and the sum of q and p is the total number of scanning points on the i-th scanning line.

10. The method according to claim 7, characterized in that The step of fitting the target point Si,q to obtain a fitting height includes: Get the heights of multiple target points within the neighborhood window centered on the target point Si,q; A linear fit is performed based on the heights of multiple target points within the neighborhood window to obtain the fitting height of the target point Si,q.

11. A laser radar detection device, characterized in that: The device comprises: A data acquisition module, used to acquire point cloud data corresponding to the i-1th ground line and point cloud data corresponding to the i-2th ground line; i is an integer greater than or equal to 3; A height calculation module, used for calculating the predicted height range of the i-th ground line based on the point cloud data corresponding to the i-1-th ground line and the point cloud data corresponding to the i-2-th ground line; A data detection module, configured to detect scanning points of the i-th scanning line based on the predicted height range, and determine a target point among the scanning points; A data generation module is used to obtain the i-th ground line according to the target point; obtain the i-th ground line based on the fitting height, and the distances between the i-2th ground line, the i-1th ground line, and the i-th ground line and the laser radar are respectively from near to far.

12. A computer storage medium, characterized in that: The computer storage medium stores a plurality of instructions, which are suitable for being loaded by a processor and executing the method steps according to any one of claims 1 to 10.

13. A laser radar, characterized in that: include: A processor and a memory; wherein the memory stores a computer program, and the computer program is suitable for being loaded by the processor and executing the method steps as claimed in any one of claims 1 to 10.

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