Laser radar calibration method, device and system

Abstract

The present application discloses a laser radar calibration method, device and system, which relates to the fields of autonomous driving and robotics. A specific embodiment of the device includes: a support seat; at least three calibration rods, which are installed on the support seat, the rod bodies of the at least three calibration rods are located in the same plane, the angle between any two adjacent calibration rods is a fixed value, and the at least three calibration rods are located on the scanning path of the light wave emitted by the laser radar. The laser radar calibration device obtained by this embodiment has a simple structure and is easy to produce and assemble.

Description

Technical Field

[0001] The embodiments of the present application relate to the fields of autonomous driving and robotics, specifically to the field of laser radar calibration technology, and in particular to laser radar calibration methods, devices and systems. Background Art

[0002] In the field of autonomous driving and robotics, LiDAR is often installed to detect and perceive obstacles in the surrounding environment. After the LiDAR is installed on the autonomous driving vehicle or robot, the external parameters of the LiDAR need to be calibrated to improve the accuracy of the LiDAR's perception of the location of surrounding obstacles.

[0003] In the prior art, the external parameters of a single-line laser radar are calibrated by an operator who first places a level on the single-line laser radar to keep the single-line laser radar level, and then directly measures the external parameters of the single-line laser radar using a caliper. Summary of the invention

[0004] Provided are a laser radar calibration method, device, system, and computer-readable medium.

[0005] According to a first aspect, a laser radar calibration device is provided, which includes: a support base; at least three calibration rods installed on the support base, the rod bodies of the at least three calibration rods are located in the same plane, the angle between any two adjacent calibration rods is a fixed value, and the at least three calibration rods are all located on the scanning path of the light waves emitted by the laser radar.

[0006] According to the second aspect, a laser radar calibration method for a laser radar calibration device as described in any implementation of the first aspect is provided, the method comprising: determining the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system based on the initial intersection points of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device; determining the coordinates of each adjusted intersection point in the radar coordinate system and the coordinates of each adjusted intersection point in the calibration rod coordinate system based on the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device; determining the external parameters of the laser radar based on the coordinates of each initial intersection point in the radar coordinate system, the coordinates of each initial intersection point in the calibration rod coordinate system, the coordinates of each adjusted intersection point in the calibration rod coordinate system, and the coordinates of each adjusted intersection point in the radar coordinate system.

[0007] According to a third aspect, a laser radar calibration system using a laser radar calibration device as described in any implementation method of the first aspect is provided, the laser radar calibration system comprising: an initial coordinate determination module, configured to determine the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system based on the initial intersection points of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device; an adjustment coordinate determination module, configured to determine the coordinates of each adjusted intersection point in the radar coordinate system and the coordinates of each adjusted intersection point in the calibration rod coordinate system based on the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device; a radar extrinsic parameter determination module, configured to determine the extrinsic parameters of the laser radar based on the coordinates of each initial intersection point in the radar coordinate system, the coordinates of each initial intersection point in the calibration rod coordinate system, the coordinates of each adjusted intersection point in the calibration rod coordinate system, and the coordinates of each adjusted intersection point in the radar coordinate system.

[0008] According to a fourth aspect, an electronic device is provided, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can execute the method described in any implementation manner of the second aspect.

[0009] According to a fifth aspect, a non-transitory computer-readable storage medium storing computer instructions is provided, where the computer instructions are used to cause a computer to execute the method described in any implementation of the second aspect.

[0010] The laser radar calibration device provided by the embodiment of the present application includes a support seat and at least three calibration rods; the rod bodies of the at least three calibration rods are located in the same plane, the angle between any two adjacent calibration rods is a fixed value, and the at least three calibration rods are located on the scanning path of the light wave emitted by the laser radar; thus, by reflecting the light wave emitted by the laser radar through at least three calibration rods with a fixed angle between any two adjacent calibration rods, the intersection point of the light wave and each calibration rod can be determined, and the coordinates of the intersection point in the calibration rod coordinate system can be determined from the intersection point, and then the external parameters of the laser radar can be calculated. The laser radar calibration device has a simple structure and is easy to produce and assemble. The laser radar calibration device can automatically calculate the external parameters of the laser radar, thereby improving the efficiency and accuracy of determining the external parameters of the laser radar.

[0011] The laser radar calibration method and system provided in the embodiments of the present application are used for the above-mentioned laser radar calibration device. First, based on the initial intersection points of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device, the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system are determined; secondly, based on the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device, the coordinates of each adjusted intersection point in the radar coordinate system and the coordinates of each adjusted intersection point in the calibration rod coordinate system are determined; finally, based on the coordinates of each initial intersection point in the radar coordinate system, the coordinates of each initial intersection point in the calibration rod coordinate system, the coordinates of each adjusted intersection point in the calibration rod coordinate system, and the coordinates of each adjusted intersection point in the radar coordinate system, the external parameters of the laser radar are determined. According to at least three calibration rods of the laser radar calibration device and the angles between adjacent calibration rods among the at least three calibration rods, the coordinates of each initial intersection point in the calibration rod coordinate system and the coordinates of the adjusted intersection point in the calibration rod coordinate system can be obtained. The coordinates of each initial intersection point in the radar coordinate system and the coordinates of the adjusted intersection point in the radar coordinate system can be obtained from the collected laser radar signal. Therefore, on the basis of adopting the laser radar calibration device of the present application, the relative distance between the laser radar calibration device and the laser radar can be adjusted once to obtain the external parameters of the laser radar accurately, efficiently and quickly.

[0012] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings are used to better understand the present solution and do not constitute a limitation of the present application.

[0014] Figure 1 is a structural schematic diagram of an embodiment of a laser radar calibration device according to the present application;

[0015] Figure 2 is a structural schematic diagram of another embodiment of the laser radar calibration device according to the present application;

[0016] Figure 3 is a structural schematic diagram of a support base according to an embodiment of the present application;

[0017] Figure 4 is a flow chart of an embodiment of a laser radar calibration method according to the present application;

[0018] Figure 5is an exemplary flow chart of a method for determining the coordinates of each initial intersection point in radar coordinates and the coordinates of each initial intersection point in a calibration rod coordinate system according to the present application;

[0019] Figure 6 is a schematic diagram of a laser radar calibration device in an application scenario according to the present application;

[0020] Figure 7 is a schematic structural diagram of an embodiment of a laser radar calibration system according to the present application;

[0021] Figure 8 It is a block diagram of an electronic device used to implement the laser radar calibration method of the present application. DETAILED DESCRIPTION

[0022] The following is a description of exemplary embodiments of the present application in conjunction with the accompanying drawings, including various details of the embodiments of the present application to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications can be made to the embodiments described herein without departing from the scope and spirit of the present application. Similarly, for the sake of clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0023] Generally speaking, sensors, such as cameras, lidars, and millimeter-wave radars, all have their own coordinate systems, and the measurement data generated by the sensors are also obtained based on the sensor's own coordinate system. However, many sensors are installed on a car or robot. In order to facilitate algorithm research and testing, the data obtained by each sensor needs to be converted to the vehicle or robot coordinate system. The process of converting to the vehicle coordinate system or the robot coordinate system is the sensor's extrinsic parameter calibration process. In order to achieve the sensor's extrinsic parameter calibration, a sensor calibration device is required.

[0024] Figure 1 The structure 100 of an embodiment of a laser radar calibration device according to the present application is shown. The laser radar calibration device 100 comprises: a support base 101, and three calibration rods 102; the three calibration rods 102 are installed on the support base 101, and the rod bodies of the three calibration rods 102 are located in the same plane, and the angle between any two adjacent calibration rods 102 is a fixed value, and the three calibration rods are located on the scanning path of the light wave emitted by the laser radar (not shown in the figure).

[0025] It should be noted that, in this embodiment, the number of the calibration rods 102 can be three or more than three. Figure 1The laser radar calibration device 100 shown in the figure is equipped with three calibration rods 102, and the three calibration rods 102 form a claw-type structure in which adjacent calibration rods have fixed angles on the support seat 101; in other optional modes of the embodiments of the present application, the number of calibration rods 102 can also be four, five, or more than three.

[0026] In this embodiment, the shape and structure of the support base 101 can be adaptively set according to the laser radar calibration requirements. For example, if the radar calibration device is installed on a robot, the support base 101 may include a clamping structure that is clamped to the robot control arm; if the radar calibration device is installed on a vehicle, the support base 101 may include a support frame fixed to the vehicle roof by bolts, etc.

[0027] In this embodiment, the fixing and installation method of at least three calibration rods on the support seat 101 is not limited. For example, the support seat 101 has a slot that matches the calibration rod 102, and the calibration rod 102 also has a clamping portion. The slot wall is provided with a clamping structure. When the clamping portion of the calibration rod 102 is inserted into the slot, it is clamped with the clamping structure, thereby fixing the calibration rod 102 in the slot. For another example, the calibration rod 102 is fixedly installed on the support seat 101 by bolts or the calibration rod 102 is welded to the support seat 101.

[0028] In this embodiment, the length of each of the at least three calibration rods can be the same or different, and the length of each calibration rod can also be set according to the calibration requirements of the laser radar, for example, the length of all calibration rods is set to 30 cm. Furthermore, in order to facilitate the carrying of the laser radar calibration device, the calibration rod can be a foldable rod. For example, when the radar calibration device does not calibrate the laser radar, at least three calibration rods are partially folded to fit the outer surface of the support; in order to meet the calibration requirements of laser radars of different ranges, the calibration rod can also be a telescopic rod. When calibration is required, the calibration rod is extended, and when calibration is not required, the calibration rod is retracted.

[0029] In this embodiment, the rod bodies of at least three calibration rods are located in the same plane, so that the light emitted by the laser radar can scan all the calibration rods in the plane, thereby improving the reliability and accuracy of the laser radar calibration. Furthermore, the laser radar calibration device of this embodiment can be used for single-line laser radars or multi-line laser radars. Single-line laser radars are single-line radars whose beams emitted by a laser source are generally only able to track the motion trajectory of a single object through plane scanning; multi-line laser radars are radars that form multiple beams of scanning through the distribution of multiple laser emission sources in the vertical direction and the rotation of a motor. Compared with single-line laser radars, they can track the motion trajectories of multiple objects. Since single-line laser radars can only scan targets in a plane and cannot measure target speeds, the rod bodies of at least three calibration rods are located in the same plane, and the calibration of the parameters of single-line laser radars can be achieved through calibration rods located in the same plane.

[0030] Furthermore, the laser radar calibration device provided in this embodiment can calibrate the external parameters of the laser radar, and the external parameters of the laser radar are the relative position and posture of the laser radar. The external parameter calibration of the laser radar refers to the process of solving the relative transformation relationship between the laser radar's own coordinate system and the coordinate system where the laser radar calibration device is located, that is, the process of solving the rotation and translation transformation matrix.

[0031] In this embodiment, the angle between any two adjacent calibration rods 102 among the at least three calibration rods may be an acute angle, an obtuse angle, or a right angle.

[0032] The angle between any two adjacent calibration rods 102 among the at least three calibration rods 102 may be the same or different. When the angle between any two adjacent calibration rods 102 among the at least three calibration rods 102 is the same, the angle includes an acute angle; when the angle between any two adjacent calibration rods 102 among the at least three calibration rods 102 is different, the angle includes an acute angle, an obtuse angle or a right angle. In this optional implementation, the angle between any two adjacent calibration rods among the at least three calibration rods is set to be the same or different, so that a variety of optional laser radar parameter calculation methods can be implemented, and the forms of laser radar parameter calculation are diversified.

[0033] The laser radar calibration device provided in this embodiment includes a support seat and at least three calibration rods; the rod bodies of the at least three calibration rods are located in the same plane, the angle between any two adjacent calibration rods is a fixed value, and the at least three calibration rods are located on the scanning path of the light wave emitted by the laser radar; thus, by reflecting the light wave emitted by the laser radar through at least three calibration rods with a fixed angle between any two adjacent calibration rods, the intersection of the light wave and each calibration rod can be determined, and the coordinates of the intersection in the calibration rod coordinate system can be determined from the intersection, and then the external parameters of the laser radar can be calculated. The laser radar calibration device has a simple structure, is easy to produce and assemble, can automatically calculate the external parameters of the laser radar, and improves the efficiency and accuracy of determining the external parameters of the laser radar.

[0034] In some optional implementations of this embodiment, such as Figure 2 As shown, the laser radar calibration device 200 includes: a support base 201, a level 203 and three calibration rods 202. The level 203 is installed on the upper surface of the support base 201, and the level 203 is configured to measure the horizontality of the support base 201.

[0035] It can be understood that the support base 201 and the three calibration rods 202 in the laser radar calibration device 200 in this implementation are respectively connected to Figure 1 The support base 101 and three calibration rods 102 in the laser radar calibration device 100 shown have the same structure.

[0036] Optionally, the level 203 can be integrated with the support base 201, or it can be Figure 2 As shown, it protrudes from the surface of the support base 201. In this optional implementation, by setting a level, the horizontality of the laser radar calibration device can be measured, so that the calibration personnel can easily and quickly understand the horizontality of the laser radar calibration device during the calibration process of the laser radar calibration device.

[0037] Continue to refer Figure 3 , Figure 3 The structure 300 of the support base according to the embodiment of the present application is shown. Figure 1 or Figure 2 The support base of the laser radar calibration device shown in FIG. Figure 3 The support base 300 shown includes: a support platform 301 and a distance measuring mechanism 302 .

[0038] The supporting platform 301 is configured to be provided with at least three calibration rods, and the planes where the rod bodies of the at least three calibration rods are located intersect with the light waves emitted by the laser radar.

[0039] The distance measuring mechanism 302 is installed on a side of the supporting platform 301 adjacent to the laser radar, and the distance measuring mechanism 302 is configured to measure the distance between the supporting platform and the laser radar.

[0040] Optionally, the distance measuring mechanism 302 can be an automatic distance meter, for example, the automatic distance meter includes: a laser distance meter, a photoelectric distance meter, an infrared distance meter, etc. The automatic distance meter can measure the relative distance between the support platform 301 and the laser radar in real time, providing a reliable basis for the external parameter mark point of the laser radar.

[0041] The distance measuring structure 302 can also be a manually operated structure. In some optional implementations of this embodiment, the distance measuring mechanism includes: a reel (not shown in the figure), a tape measure 3021 and an elastic component (not shown in the figure). The reel is fixed on the side wall of the support platform 201. The tape measure 3021 is wound on the reel, and a calibration scale is set on the tape measure 3021. One end of the elastic component is connected to the center of the reel, and the other end of the elastic component is connected to the support platform 201. The elastic component is deformed when the reel rotates.

[0042] Specifically, according to different flexibility, there are various materials that can be used for the measuring tape 3021, such as a tape measure, a cloth ruler or a steel ruler.

[0043] Specifically, the elastic component can be a spring, a torsion spring, etc. In practice, when the tape measure 3021 is a steel ruler, one end of the elastic component is connected to the outer shell of the support platform 201 or the distance measuring mechanism, and the other end of the elastic component is connected to the center of the reel. The reel can rotate. When the steel ruler is pulled, the reel will rotate with the steel ruler, and the elastic component will be suspended; when the steel ruler is released, the elastic component will pull the reel back to its original position, and then the steel ruler will also be retracted with the reel. The distance measuring mechanism provided by this optional implementation can quickly obtain the relative distance between the support platform and the laser radar by manually operating the tape measure, which is simple to implement and low in cost.

[0044] In some optional implementations of this embodiment, such as Figure 3 As shown, a level 303 may also be provided on the support base 301 . The level 303 is installed on the upper surface of the support base 300 , and is configured to measure the horizontality of the support base 300 . Figure 3 The level shown is Figure 1 and Figure 2 can have the same structure.

[0045] The support base provided in this embodiment may include a support platform and a ranging mechanism. The ranging mechanism may be configured to measure the distance between the support platform and the laser radar. The distance between the laser radar calibration device and the laser radar may be conveniently and quickly obtained through the ranging mechanism, thereby ensuring the reliability of the calibration process.

[0046] In order to adjust the horizontality of the laser radar calibration device, in some optional implementations of this embodiment, the above-mentioned laser calibration device may also include: a horizontal adjustment component, which is fixedly connected to the support base and is configured to adjust the horizontality of the support base.

[0047] Optionally, the horizontal adjustment component can manually adjust the horizontality of the support seat, or automatically adjust the horizontality of the support seat by electric, pneumatic, hydraulic drive or the like.

[0048] In a specific example, the horizontal adjustment component may include: a fixing part (not shown in the figure) and a horizontal adjustment part (not shown in the figure); wherein the cross-sectional area of ​​the fixing part is smaller than the cross-sectional area of ​​the support seat, the shape of the fixing part may be columnar, the fixing part is located below the support seat, and is used to support the support seat; the horizontal adjustment part is located around the fixing part, and the top end of the horizontal adjustment part is in conflict with the support seat, and by adjusting the position of the top end of the horizontal adjustment part, it can be used to adjust the horizontality of the support seat in different directions.

[0049] In this optional implementation, by setting a horizontal adjustment component in the laser radar calibration device, the horizontality of the laser radar calibration device can be adjusted in real time during the calibration process of the laser radar calibration device, thereby improving the calibration reliability of the laser radar calibration device.

[0050] In order to adjust the relative distance between the laser radar calibration device and the laser radar, the laser radar calibration is used to calibrate the laser radar. In some optional implementations of this embodiment, the laser radar calibration device may also include a driving mechanism (not shown in the figure), the driving mechanism is fixedly connected to the support seat or the laser radar, and the driving mechanism is configured to drive the support seat or the laser radar to adjust the relative distance between the support seat and the laser radar. Optionally, the driving mechanism may be a component that is convenient for manually applying power to the support seat or the laser radar, such as a universal wheel mounted on the support seat or the laser radar, and the relative distance between the support seat and the laser radar can be adjusted by the operator applying a driving force to the support seat or the laser radar. Optionally, the driving mechanism may also be an automatic driving component realized by electric, pneumatic, hydraulic drive, etc. For example, the driving mechanism is an electric carrier, which is loaded with the laser radar calibration device or the laser radar, and the relative distance between the support seat and the laser radar of the laser radar calibration device can be adjusted by changing the moving distance of the electric carrier.

[0051] In this optional implementation, the laser radar calibration device also includes a driving mechanism, which drives the support base or the laser radar through the driving mechanism, thereby realizing the relative displacement between the support base or the laser radar, adjusting the relative distance between the support base and the laser radar, and ensuring the effective implementation of the laser radar calibration device to calibrate the laser radar.

[0052] With respect to the above-mentioned laser radar calibration device, the present application also provides a laser radar calibration method for the above-mentioned laser radar calibration device, such as Figure 4 As shown, a process 400 of an embodiment of the laser radar calibration method of the present application is shown, and the laser radar calibration method includes:

[0053] Step 401, based on the initial intersection points of the laser radar light waves and each of the at least three calibration rods of the laser radar calibration device, determine the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system.

[0054] In this embodiment, the laser radar can be firstly assembled on the loading device manually or automatically, and the loading device is configured according to the calibration requirements, for example, the loading device includes an unmanned vehicle, a robot or other equipment that can refer to the coordinate system; secondly, the laser radar calibration device is placed at a first preset distance in front of the laser radar, that is, the laser radar calibration device is at a first preset distance relative to the laser radar, and it is ensured that the laser radar calibration device and the loading device are both in a horizontal state, at which time at least three calibration rods of the laser radar calibration device are all located on the scanning path of the light wave emitted by the laser radar. The first preset distance can be set according to the calibration requirements, for example, the first preset distance is 1 meter.

[0055] In this embodiment, the subject executing the laser radar calibration method in this embodiment can obtain the point cloud data of the laser radar in real time. The point cloud data of the laser radar refers to a set of vectors in the laser radar coordinate system. These vectors are usually expressed in the form of three-dimensional coordinates and are generally used to represent the outer surface shape value of an object.

[0056] The intersection points of the laser radar's light waves and each of the at least three calibration rods of the laser radar calibration device are determined by the laser radar's point cloud data. Depending on the different detection accuracy of the laser radar, there can be multiple intersection points between the light waves emitted by the laser radar and each calibration rod, and there are many optional implementation methods for selecting an intersection point from the multiple intersection points as the initial intersection point.

[0057] In the first implementation method of determining the initial intersection point, all the intersection points where the laser radar light wave intersects with the calibration rod are connected to form an intersection trajectory line, and the line type of the intersection trajectory line is determined. When the intersection trajectory line is a straight line, the center point of the intersection trajectory line is used as the initial intersection point; when the intersection trajectory line is an arc, the point on the intersection trajectory line that intersects with the axis line of the calibration rod is used as the initial intersection point.

[0058] In the second implementation method of determining the initial intersection point, all intersection points where the laser radar light wave intersects with the calibration rod are fitted to obtain a fitting curve, and the intersection point of the axis line of the calibration rod and the fitting curve is used as the initial intersection point.

[0059] In some optional implementations of the present embodiment, the initial intersection point of the laser radar light wave with each of the at least three calibration rods of the laser radar calibration device can also be determined in the following manner: for each calibration rod of the laser radar calibration device, all intersection points where the laser radar light wave intersects with the calibration rod are obtained; the average centroid of all intersection points where the laser radar light wave intersects with the calibration rod is calculated to obtain the initial intersection point of the calibration rod.

[0060] In this embodiment, the center of mass is the abbreviation of the mass center, and the center of mass refers to an imaginary point on the material system where the mass is considered to be concentrated; the average center of mass of all intersections is calculated: first, the coordinates of the mass point system are established, the coordinates of the center of mass of each intersection among all intersections are calculated, and the average coordinates are calculated based on the coordinates of the center of mass of all intersections to obtain the coordinates of the average center of mass. In this optional implementation, the average center of mass of all intersections where the laser radar light wave intersects with the calibration rod is calculated, and the average mass concentration point of all intersections can be obtained, which provides a basis for obtaining an accurate initial intersection point, and further improves the accuracy of laser radar calibration.

[0061] Furthermore, after the initial intersection of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device, the coordinates of each initial intersection in the radar coordinate system can be determined by the point cloud data of the laser radar.

[0062] In this embodiment, the radar coordinate system refers to the coordinate system used by the laser radar itself, and the calibration rod coordinate system refers to the coordinate system where the laser radar calibration device is located. For example, the laser radar calibration device is installed on a vehicle, and the coordinate system where the laser radar calibration device is located can adopt the vehicle coordinate system. In the vehicle coordinate system, the origin coincides with the center of mass. When the vehicle is stationary on a horizontal road, the X-axis in the vehicle coordinate is parallel to the ground and points to the front of the vehicle. The Z-axis in the vehicle coordinate points upward through the center of mass of the car, and the Y-axis in the vehicle coordinate points to the left side of the driver.

[0063] In this embodiment, after the coordinates of each initial intersection point in the radar coordinate system are determined, the coordinates of each initial intersection point in the calibration rod coordinate system can be determined by the intersection of the laser radar calibration device and the light wave of the laser radar.

[0064] Optionally, a correspondence table between the point cloud data of the laser radar and the initial intersection points of each calibration rod of at least three calibration rods of the laser radar calibration device is pre-stored in the database, and the correspondence table is obtained by measuring a large amount of actual data. After acquiring the point cloud data of the laser radar, the execution subject obtains the position of each initial intersection point on the laser radar calibration device by querying the correspondence table, and performs calibration rod coordinate system transformation based on the position of each initial intersection point to obtain the coordinates of each initial intersection point in the calibration rod coordinate system.

[0065] Step 402, based on the adjusted intersection points of the laser radar light waves and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device, determine the coordinates of each adjusted intersection point in the radar coordinate system and the coordinates of each adjusted intersection point in the calibration rod coordinate system.

[0066] In this embodiment, the executing entity can push the distance adjustment information to the operator to manually adjust the relative distance between the laser radar and the laser radar calibration device; of course, the executing entity can also directly control the driving mechanism to make the driving mechanism drive the support base of the laser radar calibration device or make the driving mechanism drive the laser radar, so as to achieve the purpose of adjusting the relative distance between the laser radar and the laser radar calibration device.

[0067] Specifically, adjusting the relative distance between the laser radar and the laser radar calibration device can adjust the distance between the laser radar and the laser radar calibration device from the original first preset distance to a second preset distance, where the second preset distance is a distance value different from the first preset distance. The second preset distance can be greater than the first preset distance, or the second preset distance can be less than the first preset distance. The specific value of the second preset distance can be set according to the calibration operation requirements, for example, the second preset distance is 2 meters.

[0068] After the relative distance between the laser radar and the laser radar calibration device is adjusted, the intersection points between the laser radar light waves and each of the at least three calibration rods will also be adjusted accordingly to obtain adjusted intersection points.

[0069] In this embodiment, after the laser radar and the laser radar calibration device adjust the relative distance, the execution subject of the laser radar calibration method in this embodiment obtains the point cloud data of the laser radar again. The intersection of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device is determined by the point cloud data of the laser radar. According to the different detection accuracy of the laser radar, the intersection of the light wave emitted by the laser radar and each calibration rod can be multiple, and there are multiple optional implementation methods for selecting an intersection point from the multiple intersection points as the adjusted intersection point, which are explained by examples below.

[0070] In the first implementation method of determining the adjusted intersection point, all the intersection points where the laser radar light wave intersects with the calibration rod are connected to form an intersection trajectory line, and the line type of the intersection trajectory line is determined. When the intersection trajectory line is a straight line, the center point of the intersection trajectory line is used as the adjusted intersection point; when the intersection trajectory line is an arc, the point on the intersection trajectory line that intersects with the axis line of the calibration rod is used as the adjusted intersection point.

[0071] In the second implementation method of determining the adjusted intersection point, all intersection points where the laser radar light wave intersects with the calibration rod are fitted to obtain a fitting curve, and the intersection point of the axis line of the calibration rod and the fitting curve is used as the adjusted intersection point.

[0072] In some optional implementations of this embodiment, the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device are determined by the following steps: after adjusting the relative distance between the laser radar and the laser radar calibration device, for each calibration rod of the laser radar calibration device, all intersection points where the laser radar light wave intersects with the calibration rod are obtained; the average centroid of all intersection points where the laser radar light wave intersects with the calibration rod is calculated to obtain the adjusted intersection points of the calibration rod.

[0073] In this optional implementation, after the relative distance between the laser radar and the laser radar calibration device is adjusted, the average center of mass of all intersections where the laser radar's light waves intersect the calibration rod is calculated, and the average mass concentration point of all intersections can be obtained, which provides a basis for obtaining accurate adjusted intersections and further improves the accuracy of the laser radar calibration.

[0074] Step 403, based on the coordinates of each initial intersection point in the radar coordinate system, the coordinates of each initial intersection point in the calibration rod coordinate system, the coordinates of each adjusted intersection point in the calibration rod coordinate system, and the coordinates of each adjusted intersection point in the radar coordinate system, determine the external parameters of the laser radar.

[0075] In this embodiment, the external parameters of the laser radar are the relative position and posture of the laser radar. Determining the external parameters of the laser radar is to solve the relative change relationship coefficient of the laser radar's own coordinate system relative to the coordinate system where the laser radar calibration device is located (that is, the calibration rod coordinate system), which is also the process of calculating the rotation and translation change matrix of the laser radar.

[0076] In a specific example, the external parameter calibration of the laser radar can be marked as a 4×4 matrix, or it can be said to be composed of a rotation matrix 3×3 and a translation matrix 3×1, that is, the laser radar's own coordinate system can be converted to the calibration rod coordinate system through some rigid body transformations (translation and rotation along the x, y, and z directions in the radar's own coordinate system). The process of determining the external parameters is to obtain the above two matrices, that is, the process of obtaining 6 quantities (a, b, c, R, P, J). The first 3 values ​​of the 6 quantities represent the distances translated along the x, y, and z directions respectively; the last 3 values ​​represent the angles of rotation along the x, y, and z directions respectively. After obtaining the 6 quantities, the translation matrix and rotation matrix can be calculated, and the laser radar's point cloud data can be converted to the calibration rod coordinate system.

[0077] Specifically, the point cloud coordinates in the radar coordinate system are expressed as (x, y, z), and the point cloud coordinates in the calibration rod coordinate system are calibrated with (X, Y, Z) external parameters, that is, to obtain the rotation parameter R and translation parameter T of the radar coordinate system relative to the calibration rod coordinate system. The point cloud coordinates in the radar coordinate system are converted to the calibration rod coordinate system through formula (1), that is,

[0078]

[0079] R is a 3×3 rotation matrix, which represents the rotation transformation between the two coordinate systems. The rotation matrix includes three independent variables, which represent the relative rotation angle between the two coordinate systems. T is a 3×1 translation matrix, which represents the translation transformation between the two coordinate systems. The translation matrix includes three independent translation variables. Formula (1) transforms the external parameter calibration of the laser radar into the solution of the coordinate transformation relationship. From the above, it can be seen that the external parameter calibration needs to determine 6 quantities, and at least six known coordinates are required to solve equation (1). The coordinates of the initial intersection point in the calibration rod coordinate system are at least 3, and the coordinates of the adjusted intersection point in the calibration rod coordinate system are at least 3, so there are at least 6 coordinates in the calibration coordinate system; the coordinates of the initial intersection point in the radar coordinate system are at least 3, and the coordinates of the adjusted intersection point in the radar coordinate system are at least 3, so there are at least 6 coordinates in the radar coordinate system. Therefore, based on the coordinates of each initial intersection point in the radar coordinate system, the coordinates of each initial intersection point in the calibration rod coordinate system, the coordinates of each adjusted intersection point in the calibration rod coordinate system, and the coordinates of each adjusted intersection point in the radar coordinate system, equation (1) can be completely solved.

[0080] The laser radar calibration method provided in the embodiment of the present application can be used to calibrate a single-line laser radar. Furthermore, since the multi-line laser radar is different from the single-line laser radar only in the beam, the laser radar calibration method provided in the embodiment of the present application can also easily calibrate the multi-line laser radar based on the single-line laser radar calibration.

[0081] It can be understood that the dimensions of the above-mentioned matrices and coordinate systems are only examples and do not represent limitations. For example, there may be matrices with more dimensions and coordinate systems with more dimensions.

[0082] The laser radar calibration method for a laser radar calibration device provided in this embodiment can obtain the coordinates of each initial intersection point in the calibration rod coordinate system and the coordinates of the adjusted intersection point in the calibration rod coordinate system according to at least three calibration rods of the laser radar calibration device and the angles between adjacent calibration rods of the at least three calibration rods. The coordinates of each initial intersection point in the radar coordinate system and the coordinates of the adjusted intersection point in the radar coordinate system can be obtained from the collected laser radar signal. Therefore, on the basis of adopting the laser radar calibration device of the present application, the external parameters of the laser radar can be accurately, efficiently and quickly obtained by adjusting the relative distance between the laser radar calibration device and the laser radar once.

[0083] In some optional implementations of this embodiment, such as Figure 5 As shown, the process 500 of the method for determining the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system may include the following steps:

[0084] Step 501, based on the initial intersection points of the laser radar light waves and each of the at least three calibration rods of the laser radar calibration device, determine the coordinates of each initial intersection point in the radar coordinate system.

[0085] In this optional implementation, after obtaining the point cloud data of the laser radar, the execution subject distinguishes the intersection points with each of the at least three calibration rods, and calculates the initial intersection point from the intersection points on each calibration rod (which can be calculated using the following method: Figure 4 Calculation method in the embodiment shown). Figure 6 As shown, p1, p2, and p3 are the calculated initial intersection points.

[0086] Furthermore, since the point cloud data of the laser radar can reflect the coordinates of the intersection point in the laser radar coordinate system, the coordinates of the initial intersection point in the radar coordinate system can be obtained according to the coordinates of each intersection point in the laser radar coordinate system.

[0087] Step 502: Determine the distance between any two adjacent initial intersection points among at least three initial intersection points based on the coordinates of each initial intersection point in the radar coordinate system.

[0088] In this embodiment, the distance between all two adjacent initial intersection points can be obtained by using the three-dimensional coordinate two-point distance formula. The three-dimensional coordinate two-point distance formula is shown in formula (2).

[0089]

[0090] Among them, the coordinates of one of the two points in the three-dimensional coordinates are (x1, y1, z1), the coordinates of the other point are (x2, y2, z2), and d is the distance between the two points in the three-dimensional coordinates.

[0091] Reference Figure 6 As shown, the distance between the initial intersection point p1 and the initial intersection point p2 is d1, and the distance between the initial intersection point p2 and the initial intersection point p3 is d2.

[0092] Step 503: Obtain the angle between two calibration poles where two initial intersection points corresponding to each distance are located.

[0093] In this embodiment, the execution subject of the laser radar calibration method can obtain each angle between two calibration rods of at least three calibration rods of the laser radar calibration device through real-time communication or memory reading. Figure 6 There are three calibration rods, and the angle between every two adjacent calibration rods is α.

[0094] Step 504, based on each distance and the angle between two calibration rods where two initial intersection points corresponding to each distance are located, calculate the actual length of each initial intersection point along the calibration rod where it is located to the support seat.

[0095] In this embodiment, when there are three calibration rods of the laser radar calibration device, when the laser radar light wave scans the three calibration rods of the laser radar calibration device, there are three points (p1, p2, p3) on the calibration rods of the laser radar calibration device that meet the collinearity, and there is only one set of point pairs whose distances between the three points meet the constraints of d1 and d2. Therefore, the actual lengths h1, h2, h3 from the initial intersection points p1, p2, p3 along their respective calibration rods to the support seat can be accurately solved.

[0096] The specific solution process is as follows: According to the angle law, equations (3) to (7) are established:

[0097]

[0098]

[0099]

[0100]

[0101]

[0102] Since d1, d2 and α are known in equations (3) to (7), h1, h2, h3, h21 and h23 are five unknowns. The five unknowns can be solved by equations (3) to (7), thereby obtaining h1, h2 and h3, that is, the actual lengths h1, h2 and h3 from the initial intersection points p1, p2 and p3 along their respective calibration rods to the support seat.

[0103] Step 505, based on the actual length from each initial intersection point along the calibration rod to the support seat, determine the coordinates of each initial intersection point in the calibration rod coordinate system.

[0104] In this embodiment, since the actual lengths h1, h2, and h3 from the initial intersection points p1, p2, and p3 along the calibration rods to the support seat have been determined, the coordinates of each initial intersection point can be obtained in the calibration rod coordinate system. For example, the calibration rod where the initial intersection point p2 is located is the y coordinate axis in the calibration rod coordinate system, and the coordinates of the initial intersection point p2 in the calibration rod coordinate system are (0, h2, 0).

[0105] In this optional implementation, based on the initial intersection of the laser radar light wave and each calibration rod in at least three calibration rods of the laser radar calibration device, the coordinates of each initial intersection in the radar coordinate system are determined; based on the coordinates of each initial intersection in the radar coordinate system, the distance between all adjacent two initial intersections in at least three initial intersections is determined; the angle between the two calibration rods where the two initial intersections corresponding to each distance are respectively located is obtained; based on each distance and the angle between the two calibration rods where the two initial intersections corresponding to each distance are respectively located, the actual length of each initial intersection along the calibration rod where it is located to the support seat is calculated; based on the actual length of each initial intersection along the calibration rod where it is located to the support seat, the coordinates of each initial intersection in the calibration rod coordinate system are determined. Thus, the angle corresponding to the distance is obtained through the distance between the two initial intersections, and based on the distance between at least three initial intersections and the angle corresponding to the distance, the actual length of each initial intersection along the calibration rod where it is located to the support seat can be accurately obtained, and then the laser radar external parameters are determined according to the actual length of each initial intersection along the calibration rod where it is located to the support seat, thereby ensuring the accuracy of the laser radar external parameter calibration.

[0106] In some optional implementations of the present embodiment, the above-mentioned method of determining the coordinates of each adjusted intersection in the radar coordinate system and the coordinates of each adjusted intersection in the calibration rod coordinate system based on the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device includes: determining the coordinates of each adjusted intersection in the radar coordinate system based on the adjusted intersection points of the laser radar light wave and each calibration rod; determining the distance between all two adjacent adjusted intersections of at least three adjusted intersections based on the coordinates of each adjusted intersection in the radar coordinate system; obtaining the angle between the two calibration rods where the two adjusted intersections corresponding to each distance are respectively located; calculating the actual length of each adjusted intersection along the calibration rod where it is located to the support seat based on each distance and the angle between the two calibration rods where the two adjusted intersections corresponding to each distance are respectively located; determining the coordinates of each adjusted intersection in the calibration rod coordinate system based on the actual length of each adjusted intersection along the calibration rod where it is located to the support seat.

[0107] In this optional implementation, due to the adjustment of the relative distance between the laser radar and the laser radar calibration device, although each adjusted intersection point differs from the corresponding initial intersection point only in the position of the calibration rod, the actual process of obtaining each adjusted intersection point is the same as the process of obtaining the initial intersection point. Therefore, in this optional implementation, the process of obtaining each adjusted intersection point and the actual length of each adjusted intersection point along the calibration rod to the support seat can be calculated by referring to the process of obtaining the initial intersection point and the process of calculating the actual length of each initial intersection point along the calibration rod to the support seat.

[0108] In this optional implementation, after adjusting the relative distance between the laser radar and the laser radar calibration device, the angle corresponding to the distance is obtained through the distance between two adjusted intersection points. Based on the distances between at least three adjusted intersection points and the angles corresponding to the distances, the actual lengths of each adjusted intersection along the calibration rod to the support seat can be accurately obtained. Then, the laser radar external parameters are determined according to the actual lengths of each initial intersection along the calibration rod to the support seat, thereby ensuring the accuracy of the laser radar external parameter calibration.

[0109] Further references Figure 7 As an implementation of the methods shown in the above figures, the present application provides an embodiment of a laser radar calibration system using any of the above laser radar calibration devices, and the system embodiment is similar to Figure 4 Corresponding to the method embodiment shown, the system can be specifically applied to various electronic devices.

[0110] like Figure 7As shown, the laser radar calibration system 700 provided in this embodiment using any of the above laser radar calibration devices includes: an initial coordinate determination module 701, an adjustment coordinate determination module 702, and a radar external parameter determination module 703. Among them, the above initial coordinate determination module 701 can be configured to determine the coordinates of each initial intersection in the radar coordinate system and the coordinates of each initial intersection in the calibration rod coordinate system based on the initial intersection of the laser radar light wave and each calibration rod of at least three calibration rods of the laser radar calibration device. The above adjustment coordinate determination module 702 can be configured to determine the coordinates of each adjusted intersection in the radar coordinate system and the coordinates of each adjusted intersection in the calibration rod coordinate system based on the adjusted intersection of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device. The above-mentioned radar external parameter determination module 703 can be configured to determine the external parameters of the laser radar based on the coordinates of each initial intersection point in the radar coordinate system, the coordinates of each initial intersection point in the calibration rod coordinate system, the coordinates of each adjusted intersection point in the calibration rod coordinate system, and the coordinates of each adjusted intersection point in the radar coordinate system.

[0111] In this embodiment, in the laser radar calibration system 700 using any of the above laser radar calibration devices: the specific processing of the initial coordinate determination module 701, the adjustment coordinate determination module 702, and the radar external parameter determination module 703 and the technical effects thereof can be referred to respectively. Figure 4 The relevant descriptions of step 401, step 402, and step 403 in the corresponding embodiment are not repeated here.

[0112] In some optional implementations of this embodiment, the initial coordinate determination module 701 includes: an initial radar coordinate unit (not shown in the figure), an initial distance determination unit (not shown in the figure), an initial angle acquisition unit (not shown in the figure), an initial length calculation unit (not shown in the figure), and an initial coordinate calibration unit (not shown in the figure). The initial radar coordinate unit can be configured to determine the coordinates of each initial intersection in the radar coordinate system based on the initial intersection of the laser radar light wave and each calibration rod of at least three calibration rods of the laser radar calibration device. The initial distance determination unit can be configured to determine the distance between all adjacent two initial intersections of at least three initial intersections based on the coordinates of each initial intersection in the radar coordinate system. The initial angle acquisition unit can be configured to obtain the angle between the two calibration rods where the two initial intersections corresponding to each distance are respectively located. The initial length calculation unit can be configured to calculate the actual length of each initial intersection along the calibration rod where each initial intersection is located to the support seat based on each distance and the angle between the two calibration rods where the two initial intersections corresponding to each distance are respectively located. The above-mentioned initial coordinate calibration unit can be configured to determine the coordinates of each initial intersection point in the calibration rod coordinate system based on the actual length from each initial intersection point along the calibration rod where it is located to the support seat.

[0113] In some optional implementations of this embodiment, the above-mentioned adjustment coordinate determination module 702 may include: an adjustment radar coordinate unit (not shown in the figure), an adjustment distance determination unit (not shown in the figure), an adjustment angle acquisition unit (not shown in the figure), an adjustment length calculation unit (not shown in the figure), and an adjustment coordinate calibration unit (not shown in the figure). The above-mentioned adjustment radar coordinate unit may be configured to determine the coordinates of each adjusted intersection in the radar coordinate system based on the adjusted intersections of the laser radar light wave and each calibration rod. The above-mentioned adjustment distance determination unit may be configured to determine the distance between all adjacent two adjusted intersections of at least three adjusted intersections based on the coordinates of each adjusted intersection in the radar coordinate system. The above-mentioned adjustment angle acquisition unit may be configured to obtain the angle between the two calibration rods where the two adjusted intersections corresponding to each distance are respectively located. The above-mentioned adjustment length calculation unit may be configured to calculate the actual length of each adjusted intersection along the calibration rod where each adjusted intersection is located to the support seat based on each distance and the angle between the two calibration rods where the two adjusted intersections corresponding to each distance are respectively located. The above-mentioned adjustment coordinate calibration unit can be configured to determine the coordinates of each adjusted intersection point in the calibration rod coordinate system based on the actual length from each adjusted intersection point along the calibration rod to the support seat.

[0114] In some optional implementations of this embodiment, the initial intersection in the initial coordinate determination module 701 is determined by the following unit: an initial intersection determination unit (not shown in the figure). The initial intersection determination unit can be configured to obtain, for each calibration rod of the laser radar calibration device, all intersections where the laser radar light wave intersects with the calibration rod; calculate the average centroid of all intersections where the laser radar light wave intersects with the calibration rod to obtain the initial intersection of the calibration rod.

[0115] In some optional implementations of this embodiment, the adjusted intersection in the above-mentioned adjustment coordinate determination module 702 is determined by the following unit: an adjustment intersection determination unit (not shown in the figure). The above-mentioned adjustment intersection determination unit can be configured to obtain all intersections where the laser radar light wave intersects with each calibration rod of the laser radar calibration device after the laser radar and the laser radar calibration device adjust the relative distance; calculate the average centroid of all intersections where the laser radar light wave intersects with the calibration rod to obtain the adjusted intersection of the calibration rod.

[0116] The laser radar calibration system provided in the embodiment of the present application is used for the above-mentioned laser radar calibration device. First, the initial coordinate determination module 701 determines the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system based on the initial intersection points of the laser radar light waves and each of the at least three calibration rods of the laser radar calibration device. Then, the coordinate determination module 702 is adjusted to determine the coordinates of each adjusted intersection in the radar coordinate system and the coordinates of each adjusted intersection in the calibration rod coordinate system based on the adjusted intersections of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device; finally, the radar external parameter determination module 703 determines the external parameters of the laser radar based on the coordinates of each initial intersection in the radar coordinate system, the coordinates of each initial intersection in the calibration rod coordinate system, the coordinates of each adjusted intersection in the calibration rod coordinate system, and the coordinates of each adjusted intersection in the radar coordinate system. On the basis of adopting the laser radar calibration device of the present application, the external parameters of the laser radar can be obtained accurately, efficiently and quickly by adjusting the relative distance between the laser radar calibration device and the laser radar once.

[0117] According to an embodiment of the present application, the present application also provides an electronic device and a readable storage medium.

[0118] like Figure 8Shown is a block diagram of an electronic device according to a document image toward detection method of an embodiment of the present application. Electronic devices are intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples, and are not intended to limit the implementation of the present application described herein and / or required.

[0119] like Figure 8 As shown, the electronic device includes: one or more processors 801, memory 802, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses 805, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the electronic device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In other embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple electronic devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 8 A processor 801 is taken as an example.

[0120] The memory 802 is a non-transient computer-readable storage medium provided in the present application. The memory stores instructions executable by at least one processor to enable at least one processor to execute the document image orientation detection method provided in the present application. The non-transient computer-readable storage medium of the present application stores computer instructions, which are used to enable a computer to execute the document image orientation detection method provided in the present application.

[0121] The memory 802 is a non-transient computer-readable storage medium that can be used to store non-transient software programs, non-transient computer executable programs and modules, such as program instructions / modules corresponding to the document image orientation detection method in the embodiment of the present application (for example, Figure 7 The processor 801 executes various functional applications and data processing of the server by running the non-transient software programs, instructions and modules stored in the memory 802, that is, the document image orientation detection method in the above method embodiment is implemented.

[0122] The memory 802 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the electronic device of the document image orientation detection method, etc. In addition, the memory 802 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage devices. In some embodiments, the memory 802 may optionally include a memory remotely arranged relative to the processor 801, and these remote memories may be connected to the electronic device of the document image orientation detection method via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0123] The electronic device of the document image orientation detection method may further include: an input device 803 and an output device 804. The processor 801, the memory 802, the input device 803 and the output device 804 may be connected via a bus or other means. Figure 8 The connection via bus 805 is taken as an example.

[0124] The input device 803 can receive input digital or character information, and generate key signal input related to user settings and function control of the electronic device of the document image toward the detection method, such as input devices such as a touch screen, a keypad, a mouse, a track pad, a touch pad, an indicator rod, one or more mouse buttons, a trackball, a joystick, etc. The output device 804 may include a display device, an auxiliary lighting device (e.g., LED) and a tactile feedback device (e.g., a vibration motor), etc. The display device may include, but is not limited to, a liquid crystal display (LCD), a light emitting diode (LED) display, and a plasma display. In some embodiments, the display device may be a touch screen.

[0125] Various implementations of the systems and techniques described herein can be realized in digital electronic circuit systems, integrated circuit systems, dedicated ASICs (application specific integrated circuits), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0126] These computer programs (also referred to as programs, software, software applications, or code) include machine instructions for programmable processors and can be implemented using high-level procedural and / or object-oriented programming languages, and / or assembly / machine languages. As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, device, and / or means (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0127] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0128] The systems and techniques described herein may be implemented in a computing system that includes back-end components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes front-end components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such back-end components, middleware components, or front-end components. The components of the system may be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), and the Internet.

[0129] A computer system may include clients and servers. Clients and servers are generally remote from each other and usually interact through a communication network. The relationship of client and server is generated by computer programs running on respective computers and having a client-server relationship to each other.

[0130] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution disclosed in this application can be achieved, and this document is not limited here.

[0131] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A laser radar calibration method using a laser radar calibration device, characterized in that: The laser radar calibration device comprises: a support base and at least three calibration rods; and The method comprises the following steps: Based on the initial intersection points of the laser radar light waves and each of the at least three calibration rods of the laser radar calibration device, determining the coordinates of each of the initial intersection points in the radar coordinate system; Determine the distance between any two adjacent initial intersection points among at least three initial intersection points based on the coordinates of each initial intersection point in the radar coordinate system; Obtaining the angle between two calibration poles where two initial intersection points corresponding to each distance are located; Based on each of the distances and the angle between the two calibration rods where the two initial intersection points corresponding to each of the distances are located, the actual length from each of the initial intersection points along the calibration rod where they are located to the support seat is calculated; Based on the actual length of each of the initial intersection points from the calibration rod where each of the initial intersection points is located to the support seat, determining the coordinates of each of the initial intersection points in the calibration rod coordinate system; Based on the adjusted intersection points of the laser radar light waves and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device, determining the coordinates of each of the adjusted intersection points in the radar coordinate system and the coordinates of each of the adjusted intersection points in the calibration rod coordinate system; The external parameters of the laser radar are determined based on the coordinates of each of the initial intersection points in the radar coordinate system, the coordinates of each of the initial intersection points in the calibration rod coordinate system, the coordinates of each of the adjusted intersection points in the calibration rod coordinate system, and the coordinates of each of the adjusted intersection points in the radar coordinate system.

2. The method according to claim 1, characterized in that The method of determining the coordinates of each initial intersection point in the radar coordinate system and the coordinates of each initial intersection point in the calibration rod coordinate system based on the initial intersection point of the laser radar light wave and each calibration rod of the at least three calibration rods of the laser radar calibration device comprises: Based on the initial intersection points of the laser radar light waves and each of the at least three calibration rods of the laser radar calibration device, determining the coordinates of each of the initial intersection points in the radar coordinate system; Determine the distance between any two adjacent initial intersection points among at least three initial intersection points based on the coordinates of each initial intersection point in the radar coordinate system; Obtaining the angle between two calibration poles where two initial intersection points corresponding to each distance are located; Based on each of the distances and the angle between the two calibration rods where the two initial intersection points corresponding to each of the distances are located, the actual length from each of the initial intersection points along the calibration rod where they are located to the support seat is calculated; Based on the actual length of each of the initial intersection points along the calibration rod where each of the initial intersection points is located to the support seat, the coordinates of each of the initial intersection points in the calibration rod coordinate system are determined.

3. The method according to claim 1, characterized in that The method of determining the coordinates of each adjusted intersection point in the radar coordinate system and the coordinates of each adjusted intersection point in the calibration rod coordinate system based on the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device comprises: Based on the adjusted intersection points of the light waves of the laser radar and the calibration rods, determining the coordinates of each of the adjusted intersection points in the radar coordinate system; Determine, based on the coordinates of each of the adjusted intersection points in the radar coordinate system, the distances between all two adjacent adjusted intersection points among at least three of the adjusted intersection points; Obtaining the angle between two calibration poles where two adjusted intersection points corresponding to each distance are located; Based on each of the distances and the angle between the two calibration rods where the two adjusted intersection points corresponding to each of the distances are located, calculating the actual length from each of the adjusted intersection points along the calibration rod where they are located to the support seat; Based on the actual length of each of the adjusted intersection points along the calibration rod where each of the intersection points is located to the support seat, the coordinates of each of the adjusted intersection points in the calibration rod coordinate system are determined.

4. The method according to any one of claims 1 to 3, characterized in that: The initial intersection point of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device is determined by the following steps: For each calibration rod of the laser radar calibration device, all intersection points where the laser radar light wave intersects with the calibration rod are obtained; the average centroid of all intersection points where the laser radar light wave intersects with the calibration rod is calculated to obtain the initial intersection point of the calibration rod.

5. The method according to claim 4, characterized in that The adjusted intersection points of the laser radar light waves obtained after adjusting the relative distance between the laser radar and the laser radar calibration device and each calibration rod are determined by the following steps: After the relative distance between the laser radar and the laser radar calibration device is adjusted, for each calibration rod of the laser radar calibration device, all intersection points where the light wave of the laser radar intersects with the calibration rod are obtained; the average centroid of all intersection points where the light wave of the laser radar intersects with the calibration rod is calculated to obtain the adjusted intersection points of the calibration rod.

6. The method according to claim 1, characterized in that The at least three calibration rods are installed on the support seat, the rod bodies of the at least three calibration rods are located in the same plane, the angle between any two adjacent calibration rods is a fixed value, and the at least three calibration rods are all located on the scanning path of the light waves emitted by the laser radar.

7. The method according to claim 1, characterized in that The support base comprises: A supporting platform is configured to set the at least three calibration rods, and the planes where the rod bodies of the at least three calibration rods are located intersect with the light waves emitted by the laser radar; A distance measuring mechanism is installed on a side of the supporting platform adjacent to the laser radar, and the distance measuring mechanism is configured to measure the distance between the supporting platform and the laser radar.

8. The method according to claim 7, characterized in that The distance measuring mechanism comprises: A reel, fixed on the side wall of the support platform; A measuring tape, wound on the reel, the measuring tape being provided with a calibration scale; An elastic component, one end of which is connected to the center of the reel, and the other end of which is connected to the support platform, wherein the elastic component is deformed when the reel rotates.

9. The method according to claim 1, characterized in that: The angles between any two adjacent calibration rods among the at least three calibration rods are the same; or The angles between any two adjacent calibration rods among the at least three calibration rods are different.

10. The method according to any one of claims 1 to 9, characterized in that: A level is installed on the upper surface of the support base, and the level is configured to measure the horizontality of the support base.

11. The method according to claim 10, characterized in that The laser radar calibration device also includes: The horizontal adjustment component is fixedly connected to the support base and is configured to adjust the horizontality of the support base.

12. The method according to claim 11, characterized in that The laser radar calibration device also includes: A driving mechanism is fixedly connected to the support base or the laser radar, and the driving mechanism is configured to drive the support base or the laser radar to adjust the relative distance between the support base and the laser radar.

13. A laser radar calibration system using a laser radar calibration device, characterized in that: The laser radar calibration device comprises: a support base and at least three calibration rods; and The system comprises: An initial radar coordinate module is configured to determine the coordinates of each initial intersection point in the radar coordinate system based on the initial intersection point of the laser radar light wave and each of the at least three calibration rods of the laser radar calibration device; An initial distance determination module is configured to determine the distance between all two adjacent initial intersection points among at least three initial intersection points based on the coordinates of each initial intersection point in the radar coordinate system; An initial angle acquisition module is configured to acquire the angle between two calibration poles where two initial intersection points corresponding to each distance are located; An initial length calculation module is configured to calculate the actual length from each initial intersection point to the support seat along the calibration rod where each initial intersection point is located based on each distance and the angle between two calibration rods where two initial intersection points corresponding to each distance are located; An initial coordinate calibration module is configured to determine the coordinates of each of the initial intersections in the calibration rod coordinate system based on the actual length of each of the initial intersections from the calibration rod where the initial intersection is located to the support seat; an adjustment coordinate determination module, configured to determine the coordinates of each adjusted intersection point in the radar coordinate system and the coordinates of each adjusted intersection point in the calibration rod coordinate system based on the adjusted intersection points of the laser radar light wave and each calibration rod obtained after adjusting the relative distance between the laser radar and the laser radar calibration device; The radar extrinsic parameter determination module is configured to determine the extrinsic parameters of the laser radar based on the coordinates of each of the initial intersection points in the radar coordinate system, the coordinates of each of the initial intersection points in the calibration rod coordinate system, the coordinates of each of the adjusted intersection points in the calibration rod coordinate system, and the coordinates of each of the adjusted intersection points in the radar coordinate system.

14. The system according to claim 13, characterized in that The adjustment coordinate determination module comprises: A radar coordinate adjustment unit is configured to determine the coordinates of each adjusted intersection point in the radar coordinate system based on the adjusted intersection points of the light waves of the laser radar and each calibration rod; an adjusted distance determination unit configured to determine the distance between all two adjacent adjusted intersection points among at least three adjusted intersection points based on the coordinates of each of the adjusted intersection points in the radar coordinate system; An adjustment angle acquisition unit is configured to acquire the angle between two calibration poles where two adjusted intersection points corresponding to each distance are located; An adjusted length calculation unit is configured to calculate the actual length from each of the adjusted intersections along the respective calibration rods to the support seat based on each of the distances and the angle between the two calibration rods where the two adjusted intersections corresponding to each of the distances are respectively located; The adjustment coordinate calibration unit is configured to determine the coordinates of each of the adjusted intersection points in the calibration rod coordinate system based on the actual length from each of the adjusted intersection points along the calibration rod where they are located to the support seat.

15. The system according to any one of claims 13-14, characterized in that: The initial intersection point in the initial coordinate determination module is determined by the following units: The initial intersection determination unit is configured to obtain all intersection points where the laser radar light wave intersects with each calibration rod of the laser radar calibration device; calculate the average centroid of all intersection points where the laser radar light wave intersects with the calibration rod to obtain the initial intersection point of the calibration rod.

16. The system according to claim 15, characterized in that The adjusted intersection point in the adjusted coordinate determination module is determined by the following units: The adjusted intersection determination unit is configured to obtain, for each calibration rod of the laser radar calibration device, all intersection points where the laser radar light wave intersects with the calibration rod after the relative distance between the laser radar and the laser radar calibration device is adjusted; calculate the average centroid of all intersection points where the laser radar light wave intersects with the calibration rod to obtain the adjusted intersection points of the calibration rod.

17. An electronic device, characterized in that: include: at least one processor; as well as a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the method according to any one of claims 1 to 12.

18. A non-transitory computer-readable storage medium storing computer instructions, characterized in that: The computer instructions are used to cause the computer to execute the method according to any one of claims 1 to 12.

Images