Lidar external parameter angle calibration method and device, computer device and medium

Abstract

The application relates to a laser radar external parameter angle calibration method and device, computer equipment and a medium, and belongs to the field of intelligent robots. The method comprises the following steps: acquiring laser radar data in a preset range; preprocessing the laser radar data to obtain target laser points; determining whether the number of target laser points is greater than a first threshold value; if the number of target laser points is greater than the first threshold value, a preset fitting algorithm is used to fit the target laser points into a plurality of straight lines in a rectangular calibration environment; according to the geometric relationship between the plurality of straight lines, a plurality of target vertex data information in the rectangular calibration environment is calculated; and according to the target vertex data information, a first angle of the target vertex relative to a laser radar coordinate system and a second angle of the target vertex relative to a robot coordinate system are calculated. After laser radar calibration, the positioning accuracy of the sweeping robot can be effectively improved, and the alignment success rate of the sweeping robot during recharging or dust collection is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser radar, in particular to a laser radar external parameter angle calibration method and device, computer equipment and medium. BACKGROUND

[0002] The sweeper is also called a sweeping robot, which is a kind of intelligent household appliance. The sweeper with a dust collector usually uses a tail to dock with a dust collection base station during charging and dust collection. Due to the structure, the tail cannot be arranged to use an infrared sensor to perform closed-loop calibration as the front part docks with a charging pile. In the prior art, the sweeper robot needs to align the front part first and then rotate 180° to dock with the tail during the process of reversing and docking. This process requires high alignment accuracy of the robot, and only laser radar can perform calibration during this process. Therefore, how to improve the measurement position and angle accuracy of the laser radar and how to calibrate the pose of the sweeper robot through the laser radar are technical problems to be solved by those skilled in the art. SUMMARY

[0003] The main purpose of the present application is a laser radar external parameter angle calibration method, device, computer equipment and storage medium, which aims to improve the measurement position and angle accuracy of the laser radar and calibrate the pose of the sweeper robot through the laser radar.

[0004] In order to achieve the above-mentioned purpose of the application, a laser radar external parameter angle calibration method is provided, which comprises the following steps:

[0005] Obtaining laser radar data in a preset range;

[0006] Preprocessing the laser radar data to obtain target laser points;

[0007] Judging whether the number of target laser points is greater than a first threshold value;

[0008] If the number of target laser points is greater than the first threshold value, a preset fitting algorithm is used to fit the target laser points into multiple straight lines in a rectangular calibration environment;

[0009] According to the geometric relationship between the multiple straight lines, multiple target vertex data information in the rectangular calibration environment is calculated;

[0010] According to the target vertex data information, a first angle of the target vertex relative to the laser radar coordinate system and a second angle of the target vertex relative to the robot coordinate system are calculated;

[0011] If the number relationship between the second angles corresponding to the target vertices satisfies a preset threshold value, the calibration is successful.

[0012] Further, the preprocessing of the laser radar data to screen target laser points comprises:

[0013] judging whether the intensity value of the laser radar point in the laser radar point cloud data is greater than a second threshold value;

[0014] if yes, the laser radar point is a target laser point;

[0015] if no, the laser radar point is not a target laser point.

[0016] Further, the judging whether the number of the target laser points is greater than a first threshold value comprises:

[0017] if no, the next frame of laser radar point cloud data is acquired.

[0018] Further, the calculating a plurality of target vertex data information in the rectangular calibration environment according to the geometric relationship between the plurality of straight lines comprises:

[0019] setting two intersection points of two pairs of perpendicular lines as A(x1, y1) and B(x2, y2);

[0020] constructing straight line equations a1x+b1y+c1=0, a2x+b2y+c2=0 and a3x+b3y+c3=0 of the two pairs of perpendicular lines;

[0021] constructing a matrix constructing a matrix

[0022] constructing a matrix constructing a matrix

[0023] according to acquiring the coordinate value of point A;

[0024] according to acquiring the coordinate value of point B;

[0025] according to acquiring the distance from the sweeping machine to point A in the laser radar coordinate system;

[0026] according to acquiring the distance from the sweeping machine to point B in the laser radar coordinate system.

[0027] Further, the according to acquiring the distance from the sweeping machine to point A in the laser radar coordinate system; according to acquiring the distance from the sweeping machine to point B in the laser radar coordinate system.

[0028] respectively determine whether the difference between the distance of the sweeping machine to the A point and the B point in the first coordinate system and the measured value is greater than a third threshold value, the measured value being the distance of the sweeping machine to the A point and the B point obtained by manual measurement;

[0029] If greater, it is determined that the calibration jig is missing, and the "obtaining a frame of laser radar data in a preset range" is re-executed;

[0030] If less, the angle information of the laser radar coordinate system relative to the robot coordinate system is obtained based on the target vertex data information.

[0031] Further, if the second angles corresponding to the target vertices satisfy a preset threshold value, the calibration is successful, comprising:

[0032] The second angles of the target vertices in the laser radar coordinate system relative to the sweeping robot coordinate system are obtained respectively;

[0033] The difference between the second angles of the target vertices in the laser radar coordinate system relative to the sweeping robot coordinate system is determined;

[0034] If the difference between the second angles is within the preset threshold value, the calibration is successful;

[0035] If the difference between the second angles is not within the preset threshold value, the calibration fails, and the next frame of laser radar point cloud data is obtained.

[0036] Further, the first angle of the target vertex relative to the laser radar coordinate system and the second angle relative to the robot coordinate system are calculated according to the target vertex data information, comprising:

[0037] If the second angles of the laser radar coordinate system and the robot coordinate system are in the second quadrant and the coordinate values of the target vertices A(x1, y1) and B(x2, y2) satisfy y1>y2,

[0038] the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 ° -arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(y2 / x2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=45 ° +arctan(y2 / x2);

[0039] If the second angle between the laser radar coordinate system and the robot coordinate system is in the first quadrant and the coordinate values of the target vertexes A(x1, y1) and B(x2, y2) satisfy y1>y2,

[0040] then the first angle of point A relative to the laser radar coordinate system is arctan(y1 / x1), the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=arctan(y1 / x1)-45 ° ; the first angle of point B relative to the laser radar coordinate system is -arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=-45 ° -arctan(x2 / y2).

[0041] If the second angle between the laser radar coordinate system and the robot coordinate system is in the third quadrant and the coordinate values of the target vertexes A(x1, y1) and B(x2, y2) satisfy y1<y2,

[0042] then the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 ° -arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=θ2=135 ° +arctan(x2 / y2).

[0043] If the second angle between the laser radar coordinate system and the robot coordinate system is in the fourth quadrant and the coordinate values of the target vertexes A(x1, y1) and B(x2, y2) satisfy y1<y2,

[0044] then the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=-135 ° -arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=θ2=-45 ° -arctan(x2 / y2).

[0045] A laser radar external parameter angle calibration device, the device comprises:

[0046] A laser radar data acquisition module acquires laser radar data within a preset range;

[0047] A screening module pre-processes the laser radar data to obtain target laser points;

[0048] A judging module judges whether the number of target laser points is greater than a first threshold;

[0049] A fitting module, if the number of target laser points is greater than the first threshold, uses a preset fitting algorithm to fit the target laser points into multiple straight lines in a rectangular calibration environment;

[0050] A data information acquisition module calculates multiple target vertex data information in the rectangular calibration environment according to the geometric relationship between the multiple straight lines;

[0051] A calculation module calculates a first angle of the target vertex relative to a laser radar coordinate system and a second angle relative to a robot coordinate system according to the target vertex data information;

[0052] A calibration module, if the number relationship between the second angles corresponding to the target vertex satisfies a preset threshold, is calibrated successfully.

[0053] The application also provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the steps of the laser radar external parameter angle calibration method.

[0054] The application relates to a laser radar external parameter angle calibration method and device, a computer device and a medium, and belongs to the field of intelligent robots. The method comprises the following steps: acquiring laser radar data within a preset range; pre-processing the laser radar data to obtain target laser points; judging whether the number of target laser points is greater than a first threshold; if the number of target laser points is greater than the first threshold, using a preset fitting algorithm to fit the target laser points into multiple straight lines in a rectangular calibration environment; calculating multiple target vertex data information in the rectangular calibration environment according to the geometric relationship between the multiple straight lines; calculating a first angle of the target vertex relative to a laser radar coordinate system and a second angle relative to a robot coordinate system according to the target vertex data information; and if the number relationship between the second angles corresponding to the target vertex satisfies a preset threshold, the calibration is successful. After laser radar calibration, the positioning accuracy of the sweeping robot can be effectively improved, and the alignment success rate of the sweeping robot during recharging or dust collection is greatly improved. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is an embodiment flowchart of the laser radar external parameter angle calibration method.

[0056] Figure 2 Figure 1 is a structural schematic diagram of an embodiment of a device for angle calibration of laser radar external parameters of the present application;

[0057] Figure 3 Figure 2 is a structural schematic block diagram of an embodiment of a computer device of the present application. DETAILED DESCRIPTION

[0058] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0059] Reference Figure 1 The embodiment of the present application provides a laser radar external parameter angle calibration method, which comprises steps S10-S70. The detailed description of each step of the laser radar external parameter angle calibration method is as follows.

[0060] S10, acquiring a frame of laser radar point cloud data.

[0061] In the embodiment, the laser radar point cloud data is a data set of space points scanned by a three-dimensional laser radar device, each point contains three-dimensional coordinate information, which is also commonly known as X, Y and Z elements, and some also contain color information, reflection intensity information, echo number information and other data information. The laser point cloud data is obtained by emitting laser signals around by a vehicle-mounted laser scanning system, collecting reflected laser signals, and then through field data collection, integrated navigation and point cloud calculation, the accurate space information of the points can be calculated, which provides information for removing invalid laser data points.

[0062] S20, preprocessing the laser radar data to obtain target laser points.

[0063] In the embodiment, the preprocessing of the laser radar data includes: determining whether the intensity value of the laser radar point in the laser radar point cloud data is greater than a second threshold value; if yes, the laser radar point is a target laser point; if no, the laser radar point is not a target laser point. Specifically, in an embodiment, the second threshold value can be set to 10, and the data with an intensity value less than 10 in the obtained laser radar data is deleted. Specifically, in another embodiment, the angle range of offset-3.14 radian to-3.14-offset radian in the laser radar coordinate system is calculated through the installation angle of the laser radar in the range of 360 degrees of the robot coordinate system, wherein the calculation method is as follows: upperBound=mInstalledAngle / 57.3+offset, lowBound=mInstalledAngle / 57.3-offset, wherein upperBound is the maximum angle value, mInstalledAngle is the installation angle of the laser radar, when the maximum angle value upperBound>3.14, the maximum angle value upperBound=

[0064] upperBound-2*3.14, when the minimum angle value lowBound<-3.14, the minimum angle value lowBound=lowBound+2*3.14, when the minimum angle value is less than the maximum angle value, it is determined whether the angle value corresponding to each point in a frame of laser radar data is between the maximum angle value and the minimum angle value, when there is a laser radar data point whose angle value is not within the range of the maximum angle value and the minimum angle value, it is indicated that the point is an invalid laser radar data point, and the point is removed from a frame of laser radar data points; when the minimum angle value is greater than or equal to the maximum angle value, it is determined whether the angle value corresponding to each point in a frame of laser radar data is less than or equal to the maximum angle value or greater than or equal to the minimum angle value, when there is a laser radar data point whose angle value does not satisfy less than or equal to the maximum angle value or greater than or equal to the minimum angle value, it is indicated that the point is an invalid laser radar data point, and the point is removed from a frame of laser radar data points, otherwise, it is retained. Through the above means, the invalid laser radar data points are removed.

[0065] S30-S50, determining whether the number of target laser points is greater than a first threshold value; if the number of target laser points is greater than the first threshold value, a preset fitting algorithm is used to fit the target laser points to obtain a plurality of straight lines in the rectangular calibration environment; and a plurality of target vertex data information in the rectangular calibration environment is calculated according to the geometric relationship between the plurality of straight lines.

[0066] In this embodiment, according to the geometric relationship between the plurality of straight lines, the plurality of target vertex data information in the rectangular calibration environment is calculated, including: setting two intersection points of two pairs of perpendicular lines as A (x1, y1) and B (x2, y2); constructing straight line equations a1x+b1y+c1=0, a2x+b2y+c2=0, and a3x+b3y+c3=0 of the two pairs of perpendicular lines; constructing a matrix constructing a matrix constructing a matrix constructing a matrix According to the coordinate value of point A is obtained; according to the coordinate value of point B is obtained; according to the distance from the laser radar coordinate system to point A is obtained; according to the distance from the laser radar coordinate system to point B is obtained. Specifically, in an embodiment, the ransac algorithm is used to fit a straight line in the target laser point, the straight line in the target laser point refers to saving the point cloud data of the laser radar point after removing the invalid laser point to the target laser point, converting the ranging value of the laser radar point after removing the invalid laser point to the laser radar coordinate system and saving it to the target laser point, fitting two pairs of perpendicular lines according to the calibration jig environment, the two pairs of perpendicular lines are three straight lines, two straight lines are perpendicular to the third straight line to form, according to the matrix equation operation, the intersection coordinates of the two perpendicular straight lines in the laser radar coordinate system are obtained, the distance from the sweeper to the intersection point is obtained according to the intersection coordinates, and the distance is compared with the artificial measurement distance. If the distance error is within a third threshold value, the third threshold value is set to 1 in this embodiment, when the error is within the third threshold value, the relative angle between the laser radar coordinate system and the robot coordinate system is calculated according to the intersection coordinates, and when the error is not within the third threshold value, the next frame of laser radar data is input. Through the above technical means, the jig environment of the laser radar point is determined.

[0067] S60-S70, according to the target vertex data information, the first angle of the target vertex relative to the laser radar coordinate system and the second angle relative to the robot coordinate system are calculated; if the quantity relationship between the second angles corresponding to the target vertex satisfies the preset threshold value, the calibration is successful.

[0068] In this embodiment, the intersection information is the coordinate values of the two intersection points of the two pairs of perpendicular lines intersecting in the laser radar coordinate system and the distances from the robot to the two intersection points; the laser radar coordinate system is a laser radar coordinate system, and the robot coordinate system is a robot coordinate system. According to the relative angle quadrant of the laser radar and the robot coordinate system and the two intersection point coordinate values, the relative angle values of the laser radar coordinate system and the robot coordinate system are calculated respectively. Specifically, in an embodiment, the two intersection point coordinates are A(x1, y1) and B(x2, y2); the relative angle between the laser radar coordinate system and the robot coordinate system is judged, which is the deviation angle between the X-axis of the laser radar coordinate system and the x-axis of the robot coordinate system. If the relative angle between the laser radar coordinate system and the robot coordinate system is in the second quadrant and the coordinate values of A and B satisfy y1>y2, then the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 ° -arctan(x1 / y1), and the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=135

[0069] 2=45 ° +arctan(y2 / x2); if the relative angle between the laser radar coordinate system and the robot coordinate system is in the first quadrant and the coordinate values of A and B satisfy y1>y2, then the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=arctan(y1 / x1)-45 ° , and the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=-45 ° -arctan(x2 / y2); if the relative angle between the laser radar coordinate system and the robot coordinate system is in the third quadrant and the coordinate values of A and B satisfy y1<y2, then the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 ° -arctan(x1 / y1), and the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=135 ° +arctan(x2 / y2); if the relative angle between the laser radar coordinate system and the robot coordinate system is in the fourth quadrant and the coordinate values of A and B satisfy y1<y2, then the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=-135 ° -arctan(x1 / y1), and the angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=-45 °arctan(x2 / y2); and obtaining a difference between the angle values of the two intersection points in the first coordinate relative to the robot coordinate system based on θ1-θ2. Through the above technical means, the relative angle value of the laser radar coordinate system and the robot coordinate system is obtained.

[0070] In one embodiment, the preprocessing of the laser radar data to screen the target laser points includes:

[0071] determining whether the intensity value of the laser radar point in the laser radar point cloud data is greater than a second threshold value;

[0072] if yes, the laser radar point is a target laser point;

[0073] if no, the laser radar point is not a target laser point.

[0074] In this embodiment, it is determined according to the intensity value of the laser radar point whether the laser radar point is valid. When the intensity value is less than the second threshold value, the laser radar point is an invalid laser radar point. The intensity value of the laser radar point in the laser radar point cloud data is a measurement index reflecting the intensity of the laser radar pulse echo generated by a point. The value is based on the reflectivity of the object scanned by the laser radar pulse to some extent. The reflectivity is a function of the wavelength (usually in the near-infrared band). The intensity of the echo varies with the composition of the surface object reflecting the echo. Specifically, in one embodiment, removing the invalid laser radar point further includes: selecting an angle range under the robot coordinate system, obtaining the maximum angle value and the minimum angle value under the laser radar coordinate system according to the angle of the laser radar coordinate system relative to the robot coordinate system, determining the relationship between the maximum angle value and the minimum angle value, determining whether the angle corresponding to each point in a frame of laser radar data points is within the angle range under the laser radar coordinate system when the minimum angle value is less than the maximum angle value, and if not, the point is an invalid laser radar point. When the minimum angle value is greater than or equal to the maximum angle value, it is determined whether the angle corresponding to each point in a frame of laser radar data points is less than or equal to the maximum angle value or greater than or equal to the minimum angle value. If one of the conditions is met, the point is an invalid laser radar point. Through the above method, the invalid laser radar point is removed.

[0075] In one embodiment, the determination of whether the number of target laser points is greater than a first threshold value includes:

[0076] if no, the next frame of laser radar point cloud data is obtained.

[0077] In this embodiment, after obtaining the data of removing invalid laser radar points, it is judged whether the number of valid laser points is less than a first threshold value. If it is less than the threshold value, the next frame of laser radar point cloud data is input to re-calibrate. If it is greater than the threshold value, two pairs of perpendicular lines are fitted according to the valid laser radar point cloud data through the ransac algorithm. The fitting of two pairs of perpendicular lines is to fit two pairs of perpendicular lines, construct a straight line equation to obtain the intersection point coordinate values of the two pairs of perpendicular lines. The basic assumption of the ransac algorithm is that the sample contains correct data (inliers, data that can be described by the model) and abnormal data (outliers, data that deviates far from the normal range and cannot adapt to the mathematical model), that is, the data set contains noise. These abnormal data may be caused by incorrect measurement, incorrect assumption, incorrect calculation, etc. At the same time, the ransac also assumes that given a set of correct data, there is a method to calculate the model parameters that meet these data. Through the above method, the intersection point coordinate values of the fitted two pairs of perpendicular lines are obtained.

[0078] In one embodiment, the calculating of the multiple target vertex data information in the rectangular calibration environment according to the geometric relationship between the multiple straight lines comprises: setting two intersection point coordinates of the two pairs of perpendicular lines as A(x1, y1) and B(x2, y2); constructing straight line equations a1x+b1y+c1=0, a2x+b2y+c2=0, and a3x+b3y+c3=0 of the two pairs of perpendicular lines; and constructing a matrix Constructing a matrix Constructing a matrix Constructing a matrix

[0079] According to The coordinate value of point A is obtained; according to The coordinate value of point B is obtained;

[0080] According to The distance from the laser radar to point A in the laser radar coordinate system is obtained; according to The distance from the laser radar to point B in the laser radar coordinate system is obtained.

[0081] In this embodiment, the laser radar data after removing invalid laser radar data points is fitted with two pairs of perpendicular lines, and two pairs of perpendicular line equations are constructed. Two perpendicular intersection points are set as A(x1, y1) and B(x2, y2). Two pairs of perpendicular line matrices are constructed to obtain the coordinate values of intersection points A and B in the laser radar coordinate system. Finally, the distances from the laser robot to points A and B are calculated according to the Pythagorean theorem. Through the above technical means, the distances from the laser robot to points A and B in the laser radar coordinate system are obtained.

[0082] In one implementation, the method further comprises obtaining a distance from the laser radar to the A point in the laser radar coordinate system; and After the step of obtaining the distance from the laser radar to the B point in the laser radar coordinate system, the method further comprises: respectively determining whether a difference between the distance from the robot to the A point and the distance from the robot to the B point in the first coordinate system and a measured value is greater than a third threshold value, the measured value being a distance from the robot to the A point and the B point obtained by manual measurement; if greater, determining that the calibration jig is missing, and re-executing the step of obtaining a frame of laser radar data in a preset range; and if smaller, obtaining angle information of the laser radar coordinate system relative to the robot coordinate system based on the target vertex data information.

[0083] In the embodiment, the laser radar coordinate system is a laser radar coordinate system, and the method further comprises obtaining distances from the robot to the intersection points A and B of the two pairs of perpendicular lines in the laser radar coordinate system, respectively comparing the distance from the robot to the A point and the distance from the robot to the B point with a manually measured value, the manually measured value being a distance from the robot to the A point and the B point measured by a measuring tool, when the difference is within a third threshold value, indicating that the calibration jig is valid, obtaining a relative angle of the laser radar coordinate system relative to the robot coordinate system according to the intersection point coordinate value, and when the difference is not within the third threshold value, inputting a next frame of laser radar data for re-calibration.

[0084] In one embodiment, if the quantity relationship between the second angles corresponding to the target vertices satisfies a preset threshold value, the calibration is successful, and the method further comprises: respectively obtaining second angles of the target vertices relative to the robot coordinate system in the laser radar coordinate system; determining a difference between the second angles of the target vertices relative to the robot coordinate system in the laser radar coordinate system; if the difference between the second angles is within the preset threshold value, the calibration is successful; and if the difference between the second angles is not within the preset threshold value, the calibration fails, and a next frame of laser radar point cloud data is obtained.

[0085] In this embodiment, the second angle value of the laser radar coordinate system relative to the sweeping robot coordinate system is obtained according to the coordinate value of point A, the second angle value of the laser radar coordinate system relative to the sweeping robot coordinate system is obtained according to the coordinate value of point B, the difference value of the second angle value of point A and the second angle value of point B is calculated, and whether the absolute value of the difference value is within the fourth threshold value is judged. When the absolute value of the difference value is within the fourth threshold value, it indicates that the laser radar calibration is successful. When the absolute value of the difference value is not within the fourth threshold value, the next frame of radar data is input to re-calibrate. Specifically, in an embodiment, the laser radar coordinate system is represented as the laser radar coordinate system, the robot coordinate system is the sweeping robot coordinate system, the angle values of A and B relative to the laser radar coordinate system are obtained according to the coordinate values of A and B under the laser radar coordinate system, and the relative angle of the laser radar coordinate value and the sweeping robot is obtained through the angle values of A and B relative to the laser radar coordinate system. Specifically, when the structure installation angle of the laser radar coordinate system is 0 to 90 degrees, if the coordinate value of point A is (x1, y1) and the coordinate value of point B is (x2, y2), the angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), the angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), the angle of the laser radar coordinate system relative to the sweeping robot coordinate system is obtained through point A, which is 45°-arctan(x1 / y1), the angle of the laser radar coordinate system relative to the sweeping robot coordinate system is obtained through point B, which is 45°+arctan(y2 / x2), and the difference value of the angle values of points A and B relative to the sweeping robot under the laser radar coordinate system is 45°-arctan(x1 / y1)-45°-arctan(y2 / x2). Whether the absolute value of the difference value is within the fourth threshold value is judged. In this embodiment, the fourth threshold value is set to 1 degree. When the error of the absolute value of the difference value is within 1 degree, it indicates that the laser radar calibration is successful. When the error of the absolute value of the difference value is not within 1 degree, it indicates that the laser radar calibration fails, and the next frame of laser radar data is input for calibration. Through the above-mentioned manner, the laser radar calibration result is determined.

[0086] In one embodiment, the target vertex data information is obtained through the laser radar, the target vertex data information includes the coordinate values of points A and B, the first angle of the target vertex relative to the laser radar coordinate system and the second angle of the target vertex relative to the robot coordinate system are calculated according to the target vertex data information, and the target vertex data information includes the coordinate values of points A and B.

[0087] When the second angle of the laser radar coordinate system and the robot coordinate system is in the second quadrant and the coordinate value y1>y2 of the target vertex A(x1, y1) and B(x2, y2), the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), the second angle of the laser radar coordinate system relative to the robot coordinate system is obtained through point A, which is θ1=45°-arctan(x1 / y1), the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), the second angle of the laser radar coordinate system relative to the robot coordinate system is obtained through point B, which is θ2=45°+arctan(x2 / y2), and the difference value of the first angle of point A and the first angle of point B relative to the laser radar coordinate system is arctan(x1 / y1)-arctan(x2 / y2). °arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=arctan(x2 / y2)-45 ° +arctan(x2 / y2);

[0088] If the second angle of the laser radar coordinate system relative to the robot coordinate system is in the first quadrant, and the coordinate values of the target vertexes A(x1, y1) and B(x2, y2) satisfy y1>y2,

[0089] the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=arctan(x1 / y1)-45 ° ; the first angle of point B relative to the laser radar coordinate system is -arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=-45 ° -arctan(x2 / y2);

[0090] If the second angle of the laser radar coordinate system relative to the robot coordinate system is in the third quadrant, and the coordinate values of the target vertexes A(x1, y1) and B(x2, y2) satisfy y1<y2,

[0091] the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 ° -arctan(x1 / y1), the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=135 ° +arctan(x2 / y2);

[0092] If the second angle of the laser radar coordinate system relative to the robot coordinate system is in the fourth quadrant, and the coordinate values of the target vertexes A(x1, y1) and B(x2, y2) satisfy y1<y2,

[0093] the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=-135 °-arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=-45 ° -arctan(x2 / y2).

[0094] In this embodiment, the laser radar coordinate system is a laser radar coordinate system, and the robot coordinate system is a robot coordinate system. According to the specific situation of the installation angle of the laser radar, the installation angle of the laser radar is divided into four cases, which are installation angle in the first quadrant, installation angle in the second quadrant, installation angle in the third quadrant, and installation angle in the fourth quadrant. The robot coordinate system takes the vertically upward direction as the x-axis and the horizontally left direction as the y-axis. Specifically, in this embodiment, when the relative angle between the laser radar coordinate system and the robot coordinate system is in the second quadrant, that is, the relative angle is 0 degrees to +90 degrees, the vertically upward direction of the robot coordinate system is taken as the x-axis, and the counterclockwise direction of the x-axis is positive. In another embodiment, when the relative angle between the laser radar coordinate system and the robot coordinate system is-90 degrees to 0 degrees, that is, the relative angle is in the first quadrant, the angle of the laser radar coordinate system relative to the robot coordinate system is the included angle between the x-axis of the first coordinate and the X-axis of the robot coordinate system. In this embodiment, the angle value of the laser radar coordinate system relative to the robot is calculated through the intersection point A coordinates of the fitted straight line in each quadrant, and the angle value of the laser radar coordinate system relative to the robot is calculated through the intersection point B coordinates. The difference between the angle values of the laser radar coordinate system relative to the robot obtained by A and B is calculated, and whether the laser radar is successfully calibrated is judged by the difference.

[0095] The application relates to a laser radar external parameter angle calibration method and device, a computer device and a medium, and belongs to the field of intelligent robots. The method comprises the following steps: acquiring laser radar data in a preset range; preprocessing the laser radar data to obtain target laser points; judging whether the number of the target laser points is greater than a first threshold value; if the number of the target laser points is greater than the first threshold value, fitting a plurality of straight lines in a rectangular calibration environment by using a preset fitting algorithm; calculating a plurality of target vertex data information in the rectangular calibration environment according to the geometric relationship between the plurality of straight lines; calculating a first angle of the target vertex relative to a laser radar coordinate system and a second angle of the target vertex relative to a robot coordinate system according to the target vertex data information; and if the number relationship between the second angles corresponding to the target vertices satisfies a preset threshold value, the calibration is successful. The positioning accuracy of the robot can be effectively improved, and the alignment success rate of the robot during charging or dust collection is greatly improved.

[0096] Reference Figure 2The application provides a device for determining an initial cleaning area of a sweeping robot, which comprises:

[0097] a laser radar data acquisition module 10 for acquiring laser radar data within a preset range;

[0098] a screening module 20 for pre-processing the laser radar data and screening target laser points;

[0099] a judging module 30 for judging whether the number of the target laser points is greater than a first threshold value;

[0100] a fitting module 40 for fitting a plurality of straight lines in a rectangular calibration environment from the target laser points by using a preset fitting algorithm if the number of the target laser points is greater than the first threshold value;

[0101] a data information acquisition module 50 for calculating a plurality of target vertex data information in the rectangular calibration environment according to geometric relationships between the plurality of straight lines;

[0102] a calculation module 60 for calculating a first angle of the target vertex relative to a laser radar coordinate system and a second angle of the target vertex relative to a robot coordinate system according to the target vertex data information;

[0103] a calibration module 70 for calibrating successfully if a quantity relationship between the second angles corresponding to the target vertex satisfies a preset threshold value.

[0104] As described above, it can be understood that each component of the laser radar external parameter angle calibration device proposed in the application can realize the function of any one of the laser radar external parameter angle calibration methods described above.

[0105] In one embodiment, the screening module 20 further comprises performing:

[0106] judging whether an intensity value of a laser radar point in the frame of laser radar point cloud data is less than a first threshold value;

[0107] if yes, the laser radar point is an invalid laser radar point;

[0108] if no, the laser radar point is a valid laser radar point.

[0109] In one embodiment, the judging module 30 further comprises performing:

[0110] if no, acquiring a next frame of laser radar point cloud data.

[0111] In one embodiment, the data information acquisition module 50 further comprises performing:

[0112] Set two pairs of vertical lines intersecting two intersection coordinates as A(x1, y1), B(x2, y2);

[0113] Construct the straight line equations a1x+b1y+c1=0, a2x+b2y+c2=0, and a3x+b3y+c3=0 of the two pairs of vertical lines;

[0114] Construct the matrix Construct the matrix

[0115] Construct the matrix Construct the matrix

[0116] According to Obtain the coordinate value of point A;

[0117] According to Obtain the coordinate value of point B;

[0118] According to Obtain the distance from the laser radar coordinate system to point A;

[0119] According to Obtain the distance from the laser radar coordinate system to point B.

[0120] In one embodiment, the data information acquisition module 50 further comprises the following steps:

[0121] Determine whether the difference between the distance from the robot to points A and B in the first coordinate system and the measured value is greater than a third threshold value, the measured value being the distance from the robot to points A and B obtained by manual measurement;

[0122] If it is greater, it is determined that the calibration tool is missing, and the step of "acquiring a frame of laser radar data in a preset range" is re-executed;

[0123] If it is less, the angle information of the laser radar coordinate system relative to the robot coordinate system is obtained based on the target vertex data information.

[0124] In one embodiment, the calibration module 70 further comprises the following steps:

[0125] Obtain the second angles of the target vertex relative to the robot coordinate system in the laser radar coordinate system, respectively;

[0126] Determine the difference between the second angles of the target vertex relative to the robot coordinate system in the laser radar coordinate system;

[0127] If the difference between the second angles is within the preset threshold value, the calibration is successful;

[0128] If the difference between the second angles is not within the preset threshold, the calibration fails, and the next frame of lidar point cloud data is acquired.

[0129] In one embodiment, the computing module 60 further comprises performing:

[0130] If the second angle between the lidar coordinate system and the robot coordinate system is in the second quadrant and the coordinate values of the target vertex A(x1, y1) and B(x2, y2) satisfy y1>y2,

[0131] the first angle of point A relative to the lidar coordinate system is arctan(x1 / y1), and the second angle of the lidar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 ° -arctan(x1 / y1); the first angle of point B relative to the lidar coordinate system is arctan(y2 / x2), and the second angle of the lidar coordinate system relative to the robot coordinate system obtained through point B is θ2=45 ° +arctan(y2 / x2);

[0132] If the second angle between the lidar coordinate system and the robot coordinate system is in the first quadrant and the coordinate values of the target vertex A(x1, y1) and B(x2, y2) satisfy y1>y2,

[0133] the first angle of point A relative to the lidar coordinate system is arctan(y1 / x1), and the second angle of the lidar coordinate system relative to the robot coordinate system obtained through point A is θ1=arctan(y1 / x1)-45 ° ; the first angle of point B relative to the lidar coordinate system is -arctan(x2 / y2), and the second angle of the lidar coordinate system relative to the robot coordinate system obtained through point B is θ2=-45 ° -arctan(x2 / y2);

[0134] If the second angle between the lidar coordinate system and the robot coordinate system is in the third quadrant and the coordinate values of the target vertex A(x1, y1) and B(x2, y2) satisfy y1<y2,

[0135] the first angle of point A relative to the lidar coordinate system is arctan(x1 / y1), and the second angle of the lidar coordinate system relative to the robot coordinate system obtained through point A is θ1=45 °arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=θ2=135 ° +arctan(x2 / y2);

[0136] If the second angle of the laser radar coordinate system and the robot coordinate system is in the fourth quadrant, and the coordinate values of the target vertex A(x1, y1) and B(x2, y2) satisfy y1

[0137] arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=θ2=135 ° -arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2=θ2=135 ° -arctan(x2 / y2).

[0138] Referring to Figure 3 In the embodiments of the present application, a computer device is also provided, and the internal structure of the computer device can be as follows Figure 3The computer device includes a processor, a memory, a network interface, a display device and an input device connected by a system bus. The network interface of the computer device is used to communicate with an external terminal through a network connection. The display device of the computer device is used to display an interactive page. The input device of the computer device is used to receive user input. The processor of the computer device is designed to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium. The non-volatile storage medium stores an operating system, a computer program and a database. The database of the computer device is used to store raw data. The computer program is executed by the processor to implement a laser radar external parameter angle calibration method. The processor executes the above-mentioned laser radar external parameter angle calibration method, which includes: acquiring a frame of laser radar data within a predetermined range; preprocessing the laser radar data to obtain target laser points; determining whether the number of target laser points is greater than a first threshold; if the number of target laser points is greater than the first threshold, using a predetermined fitting algorithm to fit the target laser points into a plurality of straight lines in a rectangular calibration environment; according to the geometric relationship between the plurality of straight lines, calculating a plurality of target vertex data information in the rectangular calibration environment; according to the target vertex data information, calculating a first angle of the target vertex relative to a laser radar coordinate system and a second angle relative to a robot coordinate system; if the number relationship between the second angles corresponding to the target vertices satisfies a predetermined threshold, the calibration is successful.

[0139] The application also provides a computer readable storage medium having a computer program stored thereon, which is executed by the processor to implement a laser radar external parameter angle calibration method, including the steps of: acquiring a frame of laser radar data within a predetermined range; preprocessing the laser radar data to obtain target laser points; determining whether the number of target laser points is greater than a first threshold; if the number of target laser points is greater than the first threshold, using a predetermined fitting algorithm to fit the target laser points into a plurality of straight lines in a rectangular calibration environment; according to the geometric relationship between the plurality of straight lines, calculating a plurality of target vertex data information in the rectangular calibration environment; according to the target vertex data information, calculating a first angle of the target vertex relative to a laser radar coordinate system and a second angle relative to a robot coordinate system; if the number relationship between the second angles corresponding to the target vertices satisfies a predetermined threshold, the calibration is successful. After laser radar calibration, the positioning accuracy of the sweeping robot can be effectively improved, and the alignment success rate of the sweeping robot during recharging or dust collection is greatly improved.

[0140] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a non-volatile computer readable storage medium, and when executed, can include the processes of the above-mentioned embodiment methods. Any reference to memory, storage, databases, or other media in this application and in examples provided herein, unless specifically stated otherwise, can include non-volatile and / or volatile memory. Non-volatile memory can include, for example, read only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include, for example, random access memory (RAM), or external cache memory. As an illustration and not a limitation, RAM is available in many forms such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), Synchlink DRAM (SLDRAM), Rambus DRAM (RDRAM), direct Rambus dynamic RAM (DRDRAM), and Rambus dynamic RAM (RDRAM), etc.

[0141] It should be noted that the terms "comprising", "including", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, a device, an article or a method that comprises a list of elements does not include only those elements recited, but can also include other elements not expressly listed or inherent to such process, device, article or method. Without further limitation, an element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the process, device, article or method that includes the element.

[0142] The above description is only the preferred embodiment of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation using the content of the specification and drawings, or direct or indirect application in other related technical fields, is also included in the patent protection scope of the present application.

Claims

1. A method for calibrating an external parameter angle of a laser radar, characterized in that, The method comprises: acquiring a frame of laser radar data within a preset range; preprocessing the laser radar data to obtain target laser points; determining whether the number of target laser points is greater than a first threshold value; if the number of target laser points is greater than the first threshold value, using a preset fitting algorithm to fit the target laser points to obtain a plurality of straight lines in a rectangular calibration environment; calculating a plurality of target vertex data information in the rectangular calibration environment according to the geometric relationship between the plurality of straight lines; calculating a first angle of the target vertex relative to a laser radar coordinate system and a second angle of the target vertex relative to a robot coordinate system according to the target vertex data information; if the number relationship between the second angles of the target vertex relative to the robot coordinate system in the laser radar coordinate system satisfies a preset threshold value, the calibration is successful.

2. The laser radar extrinsic parameter angle calibration method according to claim 1, characterized in that, The preprocessing of the laser radar data to obtain target laser points comprises: determining whether the intensity value of the laser radar point in the laser radar point cloud data is greater than a second threshold value; if yes, the laser radar point is a target laser point; if no, the laser radar point is not a target laser point; The laser radar point cloud data is a data set of space points scanned by a three-dimensional laser radar device, each point contains three-dimensional coordinate information, X, Y, and Z elements, and color information, reflection intensity information, and echo number information data information. The laser point cloud data is obtained by emitting laser signals around by a vehicle-mounted laser scanning system and collecting reflected laser signals. Through field data collection, integrated navigation, and point cloud calculation, the accurate spatial information of these points can be calculated to provide information for removing invalid laser data points.

3. The laser radar extrinsic parameter angle calibration method according to claim 1, characterized in that, The determination of whether the number of target laser points is greater than the first threshold value comprises: if no, acquiring the next frame of laser radar point cloud data.

4. The laser radar extrinsic parameter angle calibration method according to claim 1, characterized in that, The calculation of the plurality of target vertex data information in the rectangular calibration environment according to the geometric relationship between the plurality of straight lines comprises: a robot cleaner; setting two intersection coordinates of two pairs of perpendicular lines as A (x1, y1) and B (x2, y2); constructing the straight line equation of the two pairs of perpendicular lines ; Constructing matrix , constructing matrix b ; Constructing matrix , constructing matrix e= ; According to = * b get the coordinate value of point A; According to = * e get the coordinate value of point B; According to obtaining the distance from the sweeping machine to the A point in the laser radar coordinate system; According to The distance from the sweeping machine to point B in the laser radar coordinate system is obtained.

5. The laser radar extrinsic parameter angle calibration method according to claim 4, characterized in that, The method comprises the steps of: obtaining the distance from the laser radar coordinate system to the A point of the sweeper; and After the step of obtaining the distance from the laser radar coordinate system to the B point of the sweeper, the method comprises the steps of: determining whether the difference between the distance from the robot cleaner to A and B in the laser radar coordinate system and the measured value is greater than a third threshold value, the measured value being the distance from the robot cleaner to A and B obtained by manual measurement; if yes, it is determined that the calibration jig is missing, and the step of acquiring a frame of laser radar data within a preset range is re-executed; if no, the angle information of the laser radar coordinate system relative to the robot coordinate system is obtained based on the target vertex data information.

6. The laser radar extrinsic parameter angle calibration method according to claim 1, characterized in that, The calibration is successful if the number relationship between the second angles of the target vertex corresponding to the second angles satisfies a preset threshold value, which comprises: respectively acquiring the second angles of the target vertex relative to the robot cleaner coordinate system in the laser radar coordinate system; determining the difference between the second angles of the target vertex relative to the robot cleaner coordinate system in the laser radar coordinate system; if the difference between the second angles is within the preset threshold value, the calibration is successful. If the difference between the second angles is not within the preset threshold, the calibration fails, and the next frame of lidar point cloud data is acquired.

7. The laser radar extrinsic parameter angle calibration method according to claim 1, characterized in that, The calculating, according to the target vertex data information, of a first angle of the target vertex relative to a lidar coordinate system and a second angle relative to a robot coordinate system comprises: If the second angle of the lidar coordinate system relative to the robot coordinate system is in the second quadrant and the coordinate values of the target vertex A (x1, y1) and B (x2, y2) satisfy y1>y2, then the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1= -arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(y2 / x2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2= +arctan(y2 / x2); If the second angle of the lidar coordinate system relative to the robot coordinate system is in the first quadrant and the coordinate values of the target vertex A (x1, y1) and B (x2, y2) satisfy y1>y2, then the first angle of point A relative to the laser radar coordinate system is arctan(y1 / x1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1=arctan(y1 / x1) ; the first angle of point B relative to the laser radar coordinate system is -arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2= -arctan(x2 / y2) . If the second angle of the lidar coordinate system relative to the robot coordinate system is in the third quadrant and the coordinate values of the target vertex A (x1, y1) and B (x2, y2) satisfy y1<y2, then the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1= θ1+ - arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2= θ2+ + arctan(x2 / y2); If the second angle of the lidar coordinate system relative to the robot coordinate system is in the fourth quadrant and the coordinate values of the target vertex A (x1, y1) and B (x2, y2) satisfy y1<y2, then the first angle of point A relative to the laser radar coordinate system is arctan(x1 / y1), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point A is θ1= arctan(x1 / y1); the first angle of point B relative to the laser radar coordinate system is arctan(x2 / y2), and the second angle of the laser radar coordinate system relative to the robot coordinate system obtained through point B is θ2= arctan(x2 / y2).

8. A laser radar external parameter angle calibration device, characterized in that, The device comprises: A lidar data acquisition module acquires a frame of lidar data within a preset range; A screening module pre-processes the lidar data to obtain target laser points through screening; A judgment module judges whether the number of target laser points is greater than a first threshold value; A fitting module, if the number of target laser points is greater than the first threshold value, uses a preset fitting algorithm to fit the target laser points into a plurality of straight lines in a rectangular calibration environment; A data information acquisition module calculates a plurality of target vertex data information in the rectangular calibration environment according to the geometric relationship between the plurality of straight lines; A calculation module calculates a first angle of the target vertex relative to a lidar coordinate system and a second angle relative to a robot coordinate system according to the target vertex data information; A calibration module, if the quantity relationship between the second angles corresponding to the target vertex satisfies a preset threshold value, the calibration is successful. 9.A computer device, comprising a memory and a processor, wherein the memory stores a computer program, and the computer device is configured to perform the method according to any one of claims 1-8 when the computer program is executed by the processor. The processor executes the computer program to realize the steps of the lidar external parameter angle calibration method in any one of claims 1 to 7.

10. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to realize the steps of the lidar external parameter angle calibration method in any one of claims 1 to 7.

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