A calibration method, apparatus and system

Abstract

This application provides a calibration method, apparatus, and system for the sensor field, which can improve the accuracy of lidar. Furthermore, by improving the accuracy of vehicle-mounted lidar, the accuracy of autonomous driving or assisted driving can be improved. The system includes a camera, a lidar, a first diffuse reflector, and a calibration device. The lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged in parallel. The lidar emits a first laser corresponding to a first scale value of the internal code disk of the lidar, and the first laser forms a first light spot on the first diffuse reflector. The camera captures an image of the first diffuse reflector to obtain a first image. The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of a first target light point in the first image, where the first target light point is determined based on the light point in the first light spot. The lidar is calibrated based on the first scale value and the first angle.

Description

Technical Field

[0001] This application relates to the field of sensors, and more specifically, to a calibration method, apparatus, and system in the field of sensors. Background Technology

[0002] With social development and technological advancements, intelligent vehicles are gradually entering people's daily lives. Environmental perception is a crucial component of autonomous and intelligent driving in intelligent vehicles, and a vital guarantee for their safety and intelligence. Intelligent vehicles typically use sensors, such as millimeter-wave radar, lidar, ultrasonic radar, and cameras, to perceive the environment and measure targets, such as their position, distance, and speed.

[0003] However, due to various reasons such as manufacturing process or installation, there is a certain angular deviation between the actual angle and the expected angle of the laser emitted by the lidar, resulting in poor accuracy of the lidar.

[0004] Therefore, there is a need to provide a technical solution that can improve the accuracy of lidar. Summary of the Invention

[0005] This application provides a calibration method, apparatus, and system that can improve the accuracy of lidar.

[0006] In a first aspect, this application provides a calibration system, which may include a camera, a lidar, a first diffuse reflector, and a calibration device. The lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged in parallel. The lidar is used to emit a first laser, the emission angle of which corresponds to a first scale value of the code disk inside the lidar. The first laser forms a first light spot on the first diffuse reflector, the first light spot including at least one first light point. The camera is used to photograph the first diffuse reflector to obtain a first image, wherein the first image includes an image of the first light spot. The calibration device is used to determine the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, the first target light point being determined based on the at least one first light point. The lidar is calibrated based on the first scale value and the first angle.

[0007] In the above calibration system, the camera lens and the lidar window are both facing the direction of the first diffuse reflector. The laser emitted by the lidar can form a light spot (or light point) on the first diffuse reflector. The first diffuse reflector is within the camera's field of view, or the camera can capture the light spot (or light point) formed on the first diffuse reflector, and the lidar will not obstruct the camera's capture of the first diffuse reflector.

[0008] Before using the calibration system, a calibration environment for the system can be set up, in which the camera lens, the rear housing of the lidar, and the first diffuse reflector are set in parallel.

[0009] Optionally, the calibration system may also include a total station, with the camera, lidar, and first diffuse reflector all within the observation range of the total station.

[0010] In one possible implementation, the positions of the lidar's rear housing and the first diffuse reflector can be observed and measured using a total station to obtain the normal vector V1 of the rear housing and the normal vector V2 of the first diffuse reflector. Based on the angle between V1 and V2, the positions of the lidar and the first diffuse reflector are adjusted until the angle between V1 and V2 is 0, meaning the lidar's rear housing and the first diffuse reflector are parallel at 140°. Further, the camera lens can be calibrated (including intrinsic and / or extrinsic parameters) until the camera lens is parallel to the first diffuse reflector. Through these operations, the camera lens, the lidar's rear housing, and the first diffuse reflector are parallel to each other, thus completing the calibration environment setup.

[0011] Optionally, the calibration system may also include a guide rail on which the camera, the lidar, and the first diffuse reflector can be mounted, and the positions of each device can be adjusted via the guide rail to establish the aforementioned calibration environment.

[0012] Due to various reasons, such as manufacturing processes, installation techniques, installation locations, and vibrations or bumps during actual use, there may be an angular deviation between the actual angle of the laser emitted by the lidar (i.e., the angle obtained by actual measurement of the laser's emission angle) and the expected angle (i.e., the theoretical angle of the laser's emission angle obtained based on the correspondence between the emission angle and the scale value of the code disk). This angular deviation will reduce the accuracy of the lidar. Therefore, to avoid the impact of the above-mentioned angular deviation on the accuracy of the lidar, it is necessary to calibrate the lidar before or during use.

[0013] The calibration method provided in this application can be used to calibrate a lidar, thereby improving its accuracy. During calibration, the lidar can be calibrated based solely on the pixel coordinates of the light spot in the image, reducing computational complexity and thus improving calibration efficiency. Furthermore, since the calibration system establishes a calibration environment before use, the pixel coordinates are highly accurate, further enhancing the lidar's precision. In summary, the calibration method provided in this application improves the measurement performance of a lidar.

[0014] Furthermore, improving the accuracy of vehicle-mounted LiDAR can enhance the accuracy of autonomous or assisted driving.

[0015] In one possible implementation, the calibration device is specifically used to: determine the first three-dimensional coordinates of the first target light spot in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; and determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

[0016] In one possible implementation, the calibration device is further configured to determine the reference point of the three-dimensional coordinate system of the lidar and its first projection point on the first diffuse reflector; and to determine the second pixel coordinates of the first projection point in the first image; wherein, the calibration device is specifically configured to determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

[0017] It should be noted that the reference point mentioned in this application refers to the reference point used by the lidar for measurement (such as ranging). In other words, when measuring the distance of a target using lidar, the distance between the target and the reference point of the lidar is measured.

[0018] In one possible implementation, the calibration device is further configured to determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; wherein, the calibration device is specifically configured to determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

[0019] In one possible implementation, the calibration device is specifically used to: determine the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship, wherein the first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value; determine the angle deviation of the first laser based on the first angle and the third angle, wherein the angle deviation is the difference between the first angle and the third angle; determine the scale value offset of the code disk corresponding to the angle deviation; and determine the scale value of the code disk corresponding to the laser with an emission angle of the target angle based on the scale value offset.

[0020] In one possible implementation, the calibration device is specifically used to determine the first angle θ1 using the following formula:

[0021] Among them, y LA1 =M A1 ×P size y LA0 =M A0 ×P size ;

[0022] Wherein, the first three-dimensional coordinate is (x LA1 ,y LA1 ,zLA1 The second three-dimensional coordinate is (x) LA0 ,y LA0 ,z LA0 The coordinates of the first pixel are (M) A1 N A1 The coordinates of the second pixel are (M) A0 N A0 ), X LA1 =X LA0 =d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

[0023] Optionally, in order to improve the calibration accuracy, the calibration device can calibrate the lidar based on multiple sets of measurement data, wherein each set of measurement data includes a code disk value and the actual emission angle of the laser corresponding to the code disk value, and the multiple sets of measurement data include a first set of measurement data, which includes the first scale value and the first angle.

[0024] In one possible implementation, the lidar is further configured to emit a second laser beam, the emission angle of which corresponds to a second scale value of the internal code disk of the lidar. The second laser beam forms a second spot on the first diffuse reflector, the second spot including at least one second light point. The camera is further configured to capture an image of the first diffuse reflector to obtain a second image, wherein the second image includes an image of the second light spot. The calibration device is further configured to determine a second angle corresponding to the second laser beam based on the third pixel coordinates of the second target light point in the second image, the second target light point being determined based on the at least one second light point. Specifically, the calibration device is configured to calibrate the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

[0025] In one possible implementation, the first scale value, the first angle, the second scale value, and the second angle are linearly fitted to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value; based on the fitting equation, the scale value of the code disk corresponding to the target angle is determined.

[0026] By using the calibration system provided in this application and combining multiple sets of measurement data to calibrate the lidar, the calibration accuracy can be improved, thereby enhancing the measurement performance of the lidar.

[0027] In one possible implementation, the system further includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third light spot on the second diffuse reflector, the third light spot including at least one third light point. The camera is also used to capture images of the second diffuse reflector to obtain a third image, wherein the third image includes an image of the third light spot. Specifically, the calibration device is used to determine the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, and the third target light point is determined based on the at least one third light point.

[0028] In one possible implementation, the calibration device, based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, may include: determining the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; determining the third three-dimensional coordinates of the third target light point in the three-dimensional coordinate system of the lidar based on the fourth pixel coordinates; and determining the first angle based on the first three-dimensional coordinates and the third three-dimensional coordinates.

[0029] In one possible implementation, during the process of the calibration device determining the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates, the calibration device may first determine the first projection point of the reference point of the lidar's three-dimensional coordinate system on the first diffuse reflector; determine the second pixel coordinates of the first projection point in the first image; further, the calibration device may determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the lidar's three-dimensional coordinate system.

[0030] Similarly, in the process of determining the third three-dimensional coordinates of the third target light point in the three-dimensional coordinate system of the lidar based on the fourth pixel coordinates, the calibration device can first determine the second projection point of the reference point of the lidar's three-dimensional coordinate system on the second diffuse reflector; determine the fifth pixel coordinates of the second projection point in the third image; further, the calibration device can determine the third three-dimensional coordinates based on the fourth pixel coordinates, the fifth pixel coordinates, and the second distance, where the second distance represents the distance between the second diffuse reflector and the reference point of the lidar's three-dimensional coordinate system.

[0031] In one possible implementation, during the process of the calibration device determining the first angle based on the first three-dimensional coordinates and the third three-dimensional coordinates, the calibration device may first determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; then determine the fourth three-dimensional coordinates of the second projection point in the three-dimensional coordinate system of the lidar based on the second distance; furthermore, the calibration device determines the first angle based on the first three-dimensional coordinates, the second three-dimensional coordinates, the third three-dimensional coordinates, and the fourth three-dimensional coordinates.

[0032] In one possible implementation, the calibration device is specifically used to determine the first angle θ corresponding to the first target light spot on the first diffuse reflector using the following formula. 1-1 :

[0033]

[0034] Among them, y LA1 =M A1 ×P size y LA0 =M A0 ×P size The first three-dimensional coordinate is (x LA1 ,y LA1 ,z LA1 The second three-dimensional coordinate is (x) LA0 ,y LA0 ,z LA0 The coordinates of the first pixel are (M) A1 N A1 The coordinates of the second pixel are (M) A0 N A0 ), X LA1 =X LA0 =d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

[0035] In one possible implementation, the calibration device is specifically used to determine the first angle θ corresponding to the third target light spot on the second diffuse reflector using the following formula. 1-2 :

[0036]

[0037] Among them, y LB1 =M B1 ×P size y LB0 =M B0 ×P size The third three-dimensional coordinate is (x LB1 ,y LB1 ,z LB1The fourth three-dimensional coordinate is (x LB0 ,y LB0 ,z LB0 The coordinates of the fourth pixel are (M) B1 N B1 The coordinates of the fifth pixel are (M) B0 N B0 ), X LB1 =X LB0 =d2, where d2 is the second distance, P size Let be the side length of each pixel in the first image.

[0038] Since the first target light spot and the third target light spot are formed by the same beam of light (i.e., the first laser) emitted by the lidar on different diffuse reflectors, based on the parallelism of the first and second diffuse reflectors and the similarity of the light spots (or patches), it can be known that θ 1-1 =θ 1-2 =θ1.

[0039] The distance Δd between the first diffuse reflector and the second diffuse reflector can be expressed by the following formula:

[0040]

[0041] Δd can be obtained by measuring with a total station.

[0042] In summary, the first angle θ1 can be obtained by the following formula:

[0043]

[0044] The calibration method provided in this application, based on the light spot formed by the same laser on two parallel diffuse reflective plates and the relative distance between the two diffuse reflective plates, determines the first angle through the properties of similar triangles and geometric principles, which can improve the calculation accuracy of the first angle and thus improve the calibration accuracy.

[0045] Secondly, this application also provides a calibration method, which can be used in a calibration system. The system includes a camera, a lidar, a first diffuse reflector, and a calibration device. The lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged in parallel. The method includes: the lidar emitting a first laser, the emission angle of which corresponds to a first scale value of the code disk inside the lidar; the first laser forming a first light spot on the first diffuse reflector, the first light spot including at least one first light point; the camera capturing an image of the first diffuse reflector to obtain a first image, wherein the first image includes an image of the first light spot; the calibration device determining the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, the first target light point being determined based on the at least one first light point; and the calibration device calibrating the lidar based on the first scale value and the first angle.

[0046] In one possible implementation, the calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: the calibration device determining the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; and the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

[0047] In one possible implementation, the method further includes: the calibration device determining a first projection point of a reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector; the calibration device determining a second pixel coordinate of the first projection point in the first image; wherein, the calibration device determining a first three-dimensional coordinate of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinate includes: the calibration device determining the first three-dimensional coordinate based on the first pixel coordinate, the second pixel coordinate, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

[0048] In one possible implementation, the method further includes: the calibration device determining a second three-dimensional coordinate of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; wherein, the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinate includes: the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinate and the second three-dimensional coordinate.

[0049] In one possible implementation, the calibration device calibrates the lidar based on the first scale value and the first angle, including: the calibration device determining the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship, the first mapping relationship indicating the correspondence between the laser emission angle and the code disk scale value; the calibration device determining the angular deviation of the first laser based on the first angle and the third angle, the angular deviation being the difference between the first angle and the third angle; the calibration device determining the offset of the scale value of the code disk corresponding to the angular deviation; and the calibration device determining the scale value of the code disk corresponding to the laser with an emission angle of the target angle based on the scale value offset.

[0050] In one possible implementation, the method further includes: the lidar emitting a second laser, the emission angle of the second laser corresponding to a second scale value of the internal code disk of the lidar, the second laser forming a second light spot on the first diffuse reflector, the second light spot including at least one second light point; the camera capturing an image of the first diffuse reflector to obtain a second image, wherein the second image includes an image of the second light spot; the calibration device determining a second angle corresponding to the second laser based on the third pixel coordinates of the second target light point in the second image, the second target light point being determined based on the at least one second light point; wherein the calibration device calibrating the lidar based on the first scale value and the first angle includes: the calibration device calibrating the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

[0051] In one possible implementation, the calibration device calibrates the lidar based on the first scale value and the first angle, including: the calibration device performs linear fitting on the first scale value, the first angle, the second scale value, and the second angle to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value; the calibration device determines the code disk scale value corresponding to the target angle based on the fitting equation.

[0052] In one possible implementation, the system further includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third light spot on the second diffuse reflector, the third light spot including at least one third light point. The method further includes: the camera capturing an image of the second diffuse reflector to obtain a third image, wherein the third image includes an image of the third light spot; wherein the calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: the calibration device determining the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, wherein the third target light point is determined based on the at least one third light point.

[0053] In one possible implementation, the calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates, including: determining the first angle θ1 using the following formula.

[0054] Among them, y LA1 =M A1 ×P size y LA0 =M A0 ×P size ;

[0055] Wherein, the first three-dimensional coordinate is (x LA1 ,y LA1 ,z LA1 The second three-dimensional coordinate is (x) LA0 ,y LA0 ,z LA0 The coordinates of the first pixel are (M) A1 N A1 The coordinates of the second pixel are (M) A0 N A0 ), X LA1 =X LA0 =d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

[0056] In one possible implementation, the system also includes a total station, and the method further includes the total station determining the positions of the individual devices before the lidar emits the first laser.

[0057] Thirdly, this application also provides a calibration method, which can be used in a calibration device for a calibration system. The system further includes a camera, a lidar, and a first diffuse reflector. The lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged in parallel. The method includes: the calibration device acquiring a first image, which is obtained by the camera taking a picture of the first diffuse reflector. The first image contains an image of a first light spot, which is formed on the first diffuse reflector by a first laser emitted by the lidar. The first light spot includes at least one first light point, and the emission angle of the first laser corresponds to a first scale value of the code disk inside the lidar. The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image. The first target light point is determined based on the at least one first light point. The calibration device calibrates the lidar based on the first scale value and the first angle.

[0058] In one possible implementation, the method further includes: the calibration device controlling the lidar to emit the first laser; and the calibration device controlling the camera to capture an image of the first diffuse reflector to obtain the first image.

[0059] In one possible implementation, the calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: the calibration device determining the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; and the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

[0060] In one possible implementation, the method further includes: the calibration device determining a first projection point of a reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector; the calibration device determining a second pixel coordinate of the first projection point in the first image; wherein, the calibration device determining a first three-dimensional coordinate of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinate includes: the calibration device determining the first three-dimensional coordinate based on the first pixel coordinate, the second pixel coordinate, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

[0061] In one possible implementation, the method further includes: the calibration device determining a second three-dimensional coordinate of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; wherein, the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinate includes: the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinate and the second three-dimensional coordinate.

[0062] In one possible implementation, the calibration device calibrates the lidar based on the first scale value and the first angle, including: the calibration device determining the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship, the first mapping relationship indicating the correspondence between the laser emission angle and the code disk scale value; the calibration device determining the angular deviation of the first laser based on the first angle and the third angle, the angular deviation being the difference between the first angle and the third angle; the calibration device determining the offset of the scale value of the code disk corresponding to the angular deviation; and the calibration device determining the scale value of the code disk corresponding to the laser with an emission angle of the target angle based on the scale value offset.

[0063] In one possible implementation, the method further includes: the calibration device acquiring a second image, the second image being obtained by the camera capturing the first diffuse reflector, the second image containing an image of a second light spot, the second light spot being formed on the first diffuse reflector by a second laser emitted by the lidar, the second light spot including at least one second light point, the emission angle of the second laser corresponding to a second scale value of the code disk within the lidar; the calibration device determining a second angle corresponding to the second laser based on the third pixel coordinates of the second target light point in the second image, the second target light point being determined based on the at least one second light point; wherein, the calibration device calibrating the lidar based on the first scale value and the first angle includes: the calibration device calibrating the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

[0064] In one possible implementation, the calibration device calibrates the lidar based on the first scale value and the first angle, including: the calibration device performs linear fitting on the first scale value, the first angle, the second scale value, and the second angle to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value; the calibration device determines the code disk scale value corresponding to the target angle based on the fitting equation.

[0065] In one possible implementation, the system further includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third light spot on the second diffuse reflector, the third light spot including at least one third light point. The method further includes: the calibration device acquiring a third image, which is obtained by the camera capturing the second diffuse reflector, and the third image includes an image of the third light spot; wherein the calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: the calibration device determining the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, and the third target light point is determined based on the at least one third light point.

[0066] In one possible implementation, the calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates, including: determining the first angle θ1 using the following formula.

[0067] Among them, y LA1 =M A1 ×P size y LA0 =M A0 ×P size ;

[0068] Wherein, the first three-dimensional coordinate is (x LA1 ,y LA1 ,z LA1 The second three-dimensional coordinate is (x) LA0 ,y LA0 ,z LA0 The coordinates of the first pixel are (M) A1 N A1 The coordinates of the second pixel are (M) A0 N A0 ), X LA1 =X LA0 =d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

[0069] Fourthly, this application also provides a calibration device that can be used to calibrate a system. The system further includes a camera, a lidar, and a first diffuse reflector. The lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged in parallel. The calibration device includes an acquisition unit and a determination unit. The acquisition unit is used to acquire a first image, which is obtained by the camera taking a picture of the first diffuse reflector. The first image contains an image of a first light spot, which is formed on the first diffuse reflector by a first laser emitted by the lidar. The first light spot includes at least one first light point, and the emission angle of the first laser corresponds to a first scale value of the code disk inside the lidar. The determination unit is used to determine the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image. The first target light point is determined based on the at least one first light point. The lidar is calibrated based on the first scale value and the first angle.

[0070] In one possible implementation, the device further includes a first control unit and a second control unit, the first control unit being used to control the lidar to emit the first laser; the second control unit being used to control the camera to capture images of the first diffuse reflector to obtain the first image.

[0071] In one possible implementation, the determining unit is specifically used to: determine the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; and determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

[0072] In one possible implementation, the determining unit is further configured to determine the first projection point of the reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector; and to determine the second pixel coordinates of the first projection point in the first image; wherein, the determining unit is specifically configured to determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

[0073] In one possible implementation, the determining unit is further configured to determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; wherein, the determining unit is specifically configured to determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

[0074] In one possible implementation, the determining unit is specifically used to: determine the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship, wherein the first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value; determine the angle deviation of the first laser based on the first angle and the third angle, wherein the angle deviation is the difference between the first angle and the third angle; determine the scale value offset of the code disk corresponding to the angle deviation; and determine the scale value of the code disk corresponding to the laser with an emission angle of the target angle based on the scale value offset.

[0075] In one possible implementation, the acquisition unit is further configured to acquire a second image, which is obtained by the camera capturing the first diffuse reflector. The second image contains an image of a second light spot, which is formed on the first diffuse reflector by a second laser emitted by the lidar. The second light spot includes at least one second light point, and the emission angle of the second laser corresponds to a second scale value of the code disk within the lidar. The determination unit is further configured to determine a second angle corresponding to the second laser based on the third pixel coordinates of the second target light point in the second image. The second target light point is determined based on the at least one second light point. Specifically, the determination unit is configured to calibrate the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

[0076] In one possible implementation, the determining unit is specifically used to: perform linear fitting on the first scale value, the first angle, the second scale value, and the second angle to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value; and determine the scale value of the code disk corresponding to the target angle based on the fitting equation.

[0077] In one possible implementation, the system further includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third light spot on the second diffuse reflector, and the third light spot includes at least one third light point. The acquisition unit is also used to obtain a third image, which is obtained by the camera from the second diffuse reflector, and the third image contains the third light spot. Specifically, the determining unit is used to determine the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, and the third target light point is determined based on the at least one third light point.

[0078] In one possible implementation, the determining unit is specifically used to determine the first angle θ1 using the following formula:

[0079] Among them, y LA1 =M A1 ×P size y LA0 =M A0 ×P size ;

[0080] Wherein, the first three-dimensional coordinate is (x LA1 ,y LA1 ,z LA1 The second three-dimensional coordinate is (x) LA0 ,y LA0 ,z LA0 The coordinates of the first pixel are (M) A1 N A1 The coordinates of the second pixel are (M) A0 N A0 ), X LA1 =X LA0 =d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

[0081] Fifthly, this application also provides a calibration apparatus, including a memory and a processor, the memory storing computer program instructions, the processor executing the computer program instructions to perform the methods described in the third aspect above or any possible implementation thereof.

[0082] Optionally, the calibration device can be a chip device or an integrated circuit.

[0083] Sixthly, this application also provides a computer-readable storage medium, characterized in that it is used to store a computer program, which, when executed by a processor, implements the method described in the third aspect above or any possible implementation thereof.

[0084] In a seventh aspect, this application also provides a computer program product, characterized in that, when the computer program product is run on a processor, it implements the method described in the third aspect above or any possible implementation thereof.

[0085] The calibration device, computer-readable storage medium, computer program product, or chip provided in the embodiments of this application are all used to execute the corresponding methods provided above. Therefore, the beneficial effects they can achieve can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here. Attached Figure Description

[0086] Figure 1 A schematic diagram illustrating application scenarios of embodiments of this application is provided;

[0087] Figure 2 Another schematic diagram of the calibration system 100 according to an embodiment of this application is provided;

[0088] Figure 3 Another schematic diagram of the calibration system 100 according to an embodiment of this application is provided;

[0089] Figure 4 Another schematic diagram of the calibration system 100 according to an embodiment of this application is provided;

[0090] Figure 5 A schematic flowchart of the calibration method 200 according to an embodiment of this application is provided;

[0091] Figure 6 A partial schematic diagram of a calibration system 100 according to an embodiment of this application is provided;

[0092] Figure 7 A coordinate transformation diagram of an embodiment of this application is provided;

[0093] Figure 8 A schematic diagram of the linear fitting process in an embodiment of this application is provided;

[0094] Figure 9 A schematic flowchart of the calibration method 300 according to an embodiment of this application is provided;

[0095] Figure 10 Another coordinate transformation diagram of an embodiment of this application is provided;

[0096] Figure 11 A schematic block diagram of a calibration device 400 according to an embodiment of this application is provided. Detailed Implementation

[0097] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0098] First, let me introduce some of the terminology used in this application.

[0099] 1. Angle of emission

[0100] The emission angle refers to the angle between the laser emitted by the lidar and the 0° reference line. The 0° reference line can be a coordinate axis in the lidar's three-dimensional coordinate system.

[0101] 2. Zero-position light

[0102] Zero-position light refers to laser light with a horizontal emission angle of 0°.

[0103] 3. Code disk value

[0104] LiDAR controls the laser emission angle by adjusting the scale value of the internal code disk; different scale values ​​correspond to different emission angles of the laser.

[0105] For example, if the field of view of the lidar in the horizontal plane is 120° and the horizontal angular resolution is 0.4°, then the lidar has 120 / 0.4 = 300 horizontal emission angles in the horizontal plane.

[0106] It should be noted that, taking the horizontal emission angle as an example, the laser corresponding to a horizontal emission angle can correspond to a vertical emission angle on the vertical plane (such as a single-line radar); or, it can correspond to a range of vertical angles, i.e., multiple vertical emission angles (such as a multi-line radar). This application does not limit this.

[0107] For example, if the laser 1 corresponding to the horizontal emission angle 1 corresponds to the vertical emission angle 1 on the vertical plane, then the laser 1 is a single-path laser, and the imaging of this single-path laser can be a light spot formed by a single light point (which can be regarded as a special form of light spot); if the laser 1 corresponding to the horizontal emission angle 1 corresponds to multiple vertical emission angles on the vertical plane, then the laser 1 includes a laser beam composed of multiple vertically emitted lasers, and the imaging of this laser beam can be a light spot formed by multiple light points.

[0108] Figure 1 The illustration shows a schematic diagram of an application scenario provided by an embodiment of this application, such as... Figure 1 As shown, a lidar emits a laser, receives the reflected light after the laser is reflected by the target, and measures the reflected light, such as for distance measurement, velocity measurement, or positioning.

[0109] Optionally, this lidar can be applied to scenarios such as unmanned driving, autonomous driving, intelligent driving, or connected driving where target objects are measured by detection signals.

[0110] Optionally, the lidar described in this application can be applied to a terminal.

[0111] For example, the terminal can be a transportation vehicle or a smart device. The terminal can be a motor vehicle (such as an autonomous vehicle, intelligent vehicle, electric vehicle, digital car, etc.), drone, rail vehicle, bicycle, traffic light, etc. The terminal can be a mobile phone, tablet, laptop, personal digital assistant, point-of-sale terminal, in-vehicle computer, augmented reality device, virtual reality device, wearable device, vehicle terminal, etc.

[0112] However, due to various reasons, such as manufacturing processes, installation techniques, installation locations, and vibrations or bumps during actual use, there may be an angular deviation between the actual angle of the laser emitted by the lidar (i.e., the angle obtained by actual measurement of the laser's emission angle) and the expected angle (i.e., the theoretical angle of the laser's emission angle obtained based on the correspondence between the emission angle and the scale value of the code disk). This angular deviation will reduce the accuracy of the lidar. Therefore, to avoid the impact of the aforementioned angular deviation on the lidar's accuracy, the lidar needs to be calibrated before or during use.

[0113] Figure 2 A schematic diagram of a calibration system 100 provided in an embodiment of this application is shown. Figure 2 As shown, the system 100 may include a camera 120 (such as an infrared camera), a lidar 130, a first diffuse reflector 140, and a calibration device 150. The lens 121 of the camera 120 and the viewing window 131 of the lidar 130 are both oriented towards the positive x-axis. The laser emitted by the lidar 130 can form a light spot (or light point) on the first diffuse reflector 140. The first diffuse reflector 140 is within the field of view (FOV) of the camera 120, or the camera 120 can capture the light spot (or light point) formed on the first diffuse reflector 140, and the lidar 130 does not obstruct the camera 120's capture of the first diffuse reflector 140.

[0114] In use such Figure 2 Before the system 100 shown, a calibration environment for the system 100 can be set up. In this calibration environment, the lens 121 of the camera 120, the rear housing 132 of the lidar 130, and the first diffuse reflector 140 are parallel to each other.

[0115] Optionally, the system 100 may also include a total station 110, with a camera 120, a lidar 130, and a first diffuse reflector 140 all within the observation range of the total station 110.

[0116] In one possible implementation, such as Figure 2As shown, the positions of the rear housing 132 of the lidar 130 and the first diffuse reflector 140 can be observed and measured using a total station 110 to obtain the normal vector V1 of the rear housing 132 and the normal vector V2 of the first diffuse reflector 140. Based on the angle between V1 and V2, the positions of the lidar 130 and the first diffuse reflector 140 are adjusted until the angle between V1 and V2 is 0, i.e., the rear housing 132 of the lidar 130 and the first diffuse reflector 140 are parallel. Furthermore, the parameters (including intrinsic and / or extrinsic parameters) of the lens 121 of the camera 120 can be calibrated until the lens 121 of the camera 120 and the first diffuse reflector 140 are parallel. Through the above operations, the lens 121 of the camera 120, the rear housing 132 of the lidar 130, and the first diffuse reflector 140 are parallel to each other, i.e., the calibration environment is established.

[0117] After setting up the calibration environment, you can use Figure 2 The system 100 shown calibrates the lidar 130.

[0118] In one possible implementation, the lidar 130 emits a laser 1, which forms a light spot 1 on a first diffuse reflector 140. A camera 120 captures an image of the first diffuse reflector 140 through a lens 121 to obtain an image 1 containing the light spot 1; this image 1 is then sent to a calibration device 150. The calibration device 150 calibrates the lidar 130 based on this image 1 using the calibration method provided in this application embodiment (described in detail below).

[0119] Optionally, the system 100 may further include a first control device 151 and a second control device 152. The first control device 151 is used to control the lidar 130 to emit the laser 1. The second control device 152 is used to control the camera 120 to capture the image 1 and to control the camera 120 to send the image 1 to the calibration device.

[0120] Optionally, this application does not limit the specific form of the calibration device 150, the first control device 151, and the second control device 152.

[0121] In one possible implementation, the calibration device 150, the first control device 151, and the second control device 152 can be three independent devices; or, the first control device 151 can be integrated into the calibration device 150 or be a functional unit in the calibration device 150, and the second control device 152 is an independent device; or, the second control device 152 can be integrated into the calibration device 150 or be a functional unit in the calibration device 150, and the first control device 151 is an independent device; or, both the first control device 151 and the second calibration device 152 can be integrated into the calibration device 150 or be functional units in the calibration device 150.

[0122] Optionally, Figure 3 Another schematic diagram of the calibration system 100 provided in this application embodiment is shown, as follows: Figure 3 As shown, the system 100 may further include a second diffuse reflector 160, meaning it may include at least two diffuse reflectors. The laser emitted by the lidar 130 can also form a light spot (or point of light) on the second diffuse reflector 160. The second diffuse reflector 160 is within the field of view (FOV) of the camera 120, or the camera 120 can capture the light spot (or point of light) formed on the second diffuse reflector 160, and the lidar 130 does not obstruct the camera 120's capture of the second diffuse reflector 160.

[0123] For example, after the laser 1 forms the light spot 1 on the first diffuse reflector 140 and the camera 120 captures the image 1, the laser 1 can form the light spot 2 on the second diffuse reflector 160 by raising or lowering the first diffuse reflector 140 or moving the first diffuse reflector 140 in the y-axis direction, so that the camera 120 can capture the image 2.

[0124] In use such Figure 3 Before the system 100 shown, a calibration environment for the system 100 can be set up using a method similar to that described above. In this calibration environment, the lens 121 of the camera 120, the rear housing 132 of the lidar 130, the first diffuser 140, and the second diffuser 160 are parallel to each other (i.e., the lens 121 of the camera 120 is parallel to the first diffuser 140 and the diffuser 150, and the normal vector V1 of the rear housing 132 of the lidar 130, the normal vector V2 of the first diffuser 140, and the normal vector V3 of the second diffuser 160 are parallel to each other).

[0125] In one possible implementation, the lidar 130 emits a laser 1, which can form a light spot 1 on a first diffuse reflector 140 and a light spot 2 on a second diffuse reflector 160. A camera 120 is used to capture an image 1 of the first diffuse reflector 140 through a lens 121, which includes an image of the light spot 1; and to capture an image 2 of the second diffuse reflector 160 through the lens 121, which includes an image of the light spot 2; and to send images 1 and 2 to a calibration device 150. The calibration device 150 is further used to calibrate the lidar 130 based on images 1 and 2, using the calibration method provided in the embodiments of this application (described in detail below).

[0126] Optionally, this application does not limit whether the positions of the camera 120, the lidar 130, the first diffuse reflector 140, and the second diffuse reflector 160 are consistent in the y-axis direction.

[0127] In one possible implementation, Figure 4 Another schematic diagram of the calibration system 100 provided in an embodiment of this application is shown. For example... Figure 4 As shown, the system 100 may also include a guide rail 170, wherein the camera 120, the lidar 130, the first diffuse reflector 140 and the second diffuse reflector 160 are mounted on the guide rail 170, and the positions of each device can be adjusted through the guide rail 170 to build the aforementioned calibration environment.

[0128] Optionally, the total station 110 can also be used to determine the position of each device and the distance between each device, such as the distance between the reference point of the first diffuse reflector 140 and the lidar 130, and the distance between the first diffuse reflector 140 and the second diffuse reflector 160.

[0129] Optionally, a calibration environment can be set up once before the first use of system 100, or a calibration environment can be set up once before each use of system 100. This application embodiment does not limit this.

[0130] The above combination Figures 2 to 4 The system 100 provided in the embodiments of this application has been introduced. The calibration method for the system 100 will be described below.

[0131] Optionally, the lidar can be calibrated using the calibration method provided in this application before it leaves the factory or before its first use; or, if the original calibration becomes inaccurate due to problems such as shaking or bumps during the use of the lidar, the lidar can be recalibrated using the calibration method provided in this application. This application does not limit this to the following.

[0132] Figure 5 A schematic flowchart of the calibration method 200 provided in an embodiment of this application is shown, such as... Figure 5 As shown, method 200 can be applied to the above system 100, and method 200 may include the following steps.

[0133] S201. The lidar emits a first laser, the emission angle of which corresponds to a first scale value of the code disk inside the lidar, and the first laser forms a first light spot on a first diffuse reflector plate, the first light spot including at least one first light point.

[0134] Optionally, the lidar can be lidar 130 in system 100, and the first diffuse reflector can be first diffuse reflector 140 in system 100.

[0135] Example, Figure 6 A partial schematic diagram of the system 100 provided in an embodiment of this application is shown, as follows: Figure 6As shown, the lidar 130 emits a first laser, the emission angle of which corresponds to the first scale value of the code disk within the lidar. The first laser forms a pattern on the first diffuse reflector 140 as shown in the image. Figure 6 In The first light spot shown includes at least one such as Figure 6 The first light spot indicated by the "●" in the diagram is the reference point of the lidar 130 and its first projection point on the first diffuse reflector 140, as shown in the diagram. Figure 6 As shown by the "○" in the image.

[0136] S202. The camera captures an image of the first diffuse reflector to obtain a first image, wherein the first image contains an image of the first light spot.

[0137] Alternatively, the camera can be camera 120 in system 100.

[0138] Optionally, the first image may include an image of the first diffuser, wherein the image of the first diffuser includes an image of the first light spot.

[0139] S203. The camera sends the first image to the calibration device; correspondingly, the calibration device receives the first image from the camera.

[0140] S204. The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light spot in the first image, wherein the first target light spot is determined based on the at least one first light spot.

[0141] Optionally, prior to S204, the calibration device may determine the first target light spot based on the at least one first light spot.

[0142] Optionally, the calibration device can determine the first target light spot based on the at least one first light spot in a variety of ways, and the embodiments of this application do not limit this.

[0143] In one possible implementation, the calibration device can select any one of the at least one first light spot as the first target light spot.

[0144] For example, the calibration device can select the first light spot at the center position of the at least one first light spot as the first target light spot.

[0145] For example, the calibration device can select the brightest first light spot among the at least one first light spot as the first target light spot.

[0146] For example, the calibration device can select the first light spot with the largest energy / power value among the at least one first light spot as the first target light spot.

[0147] In another possible implementation, the calibration device can generate the first target light spot based on the at least one first light spot.

[0148] For example, the calibration device can generate a new first light spot, i.e., the first target light spot, located at the geometric center of the first light spot, based on the at least one light spot. Optionally, the energy / power value of the first target light spot can be the average of the energy / power values ​​of the at least one first light spot.

[0149] Example, Figure 7 A schematic diagram of the first image is shown, wherein the first image includes, for example, The image shows the first light spot, the image of the first target light spot as shown by "●", and the image of the first projection point of the reference point as shown by "○".

[0150] Optionally, in S204, the calibration device can determine the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; and determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

[0151] In one possible implementation, during the process of the calibration device determining the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates, the calibration device may first determine the first projection point of the reference point of the lidar's three-dimensional coordinate system on the first diffuse reflector, and determine the second pixel coordinates of the first projection point in the first image; further, the calibration device may determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the lidar's three-dimensional coordinate system.

[0152] It should be noted that the reference point mentioned in this application refers to the reference point used by the lidar for measurement (such as ranging). In other words, when measuring the distance of a target using lidar, the distance between the target and the reference point of the lidar is measured.

[0153] In one possible implementation, during the process of the calibration device determining the emission angle of the first laser as the first angle based on the first three-dimensional coordinates, the calibration device may first determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; further, the calibration device may determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

[0154] For example, such as Figure 7As shown, each pixel block in the first image (e.g.) Figure 7 The dimension of the symbol (indicated by "■") is P. size ×P size The first pixel coordinate of the first target light point in the coordinate system MON is (M A1 N A1 The second pixel coordinate of the first projection point of the reference point in coordinate system MON is (M A0 N A0 The first distance is d1, and the first target light spot is in the coordinate system O of the lidar. L X L Y L Z L The first three-dimensional coordinate (x) LA1 ,y LA1 ,z LA1 ) is (d1, (M A1 -M A0 )×P size ,(N A1 -N A0 )×P size The first projection point is in the coordinate system O of the lidar. L X L Y L Z L The second three-dimensional coordinates (x) below LA0 ,y LA0 ,z LA0 Let θ be (d1,0,0), where d1 can be obtained by measuring with a total station. Then, the first angle θ1 can be obtained by the following formula 1.

[0155]

[0156] S205. The calibration device calibrates the lidar based on the first scale value and the first angle.

[0157] In other words, the actual angle of the first laser's emission angle can be determined by the above steps S201 to S204 as the first angle.

[0158] Specifically, the calibration device can determine the emission angle of the first laser as a third angle, i.e. the expected angle, based on the first scale value and the preset first mapping relationship. The third angle is different from the first angle. The first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value. Based on the first angle and the third angle, the lidar is calibrated.

[0159] In other words, the emission angle of the first laser corresponding to the first scale value should theoretically be equal to the aforementioned third angle. However, due to the various reasons mentioned above, the emission angle of the first laser corresponding to the first scale value is actually equal to the aforementioned first angle. That is, there is an angular deviation between the expected angle and the actual angle. Therefore, the calibration device needs to calibrate the lidar based on this angular deviation to eliminate it.

[0160] In one possible implementation, the calibration device can determine the angular deviation of the first laser based on the first angle and the third angle, where the angular deviation is the difference between the first angle and the third angle; determine the scale value offset of the code disk corresponding to the angular deviation; and determine the scale value of the code disk corresponding to the laser with an emission angle of the target angle based on the scale value offset. In other words, when emitting a laser with an emission angle of the target angle, the calibration device can additionally adjust the range of the aforementioned scale value offset based on the code disk value corresponding to the target angle.

[0161] For example, taking the target angle as the aforementioned third angle, the calibration device can adjust the scale value of the code disk from the first scale value to the third scale value based on the scale value offset. The difference between the third scale value and the first scale value is the scale value offset. After the above adjustment, the aforementioned angle deviation can be eliminated, that is, the actual angle of the first laser can be equal to the expected angle.

[0162] For example, taking a code disk with an accuracy of 0.2° (i.e., the angle difference between two adjacent scale values ​​is 0.2°) and a first scale value of 6 as an example, the expected angle of the first laser's emission angle is 1.2°, and the actual angle of the first laser's emission angle is 1.3°. The calibration device can determine that the angle deviation between the actual angle and the expected angle is 0.1 degrees (i.e., 1.3 - 1.2 = 0.1), and this angle deviation corresponds to a scale value offset of 0.5 on the code disk. Furthermore, the calibration device can adjust the scale value of the code disk from 6 to 6.5 (i.e., 6 + 0.5 = 6.5). After adjustment, when the scale value is 6.5, the emission angle of the laser emitted by the lidar can be the aforementioned expected angle of 1.2°.

[0163] As can be seen, the calibration method provided in this application can be used to calibrate a LiDAR. During the calibration process, the LiDAR can be calibrated based solely on the pixel coordinates of the light spot in the image, reducing computational complexity and workload, thereby improving the efficiency of LiDAR calibration. Furthermore, since the calibration system establishes a calibration environment before use, the pixel coordinates have high accuracy, thus improving the accuracy of the LiDAR. In summary, the calibration method provided in this application can improve the measurement performance of a LiDAR.

[0164] Furthermore, improving the accuracy of vehicle-mounted LiDAR can enhance the accuracy of autonomous or assisted driving.

[0165] Optionally, in order to improve the calibration accuracy, the calibration device can calibrate the lidar based on multiple sets of measurement data, wherein each set of measurement data includes a scale value and the actual angle of the laser emission angle corresponding to the scale value, and the multiple sets of measurement data include a first set of measurement data, which includes the first scale value and the first angle.

[0166] In one possible implementation, prior to S205, method 200 may further include: the lidar emitting a second laser, the emission angle of the second laser corresponding to a second scale value of the internal code disk of the lidar; the second laser forming a second light spot on the first diffuse reflector, the second light spot including at least one second light point; the camera capturing an image of the first diffuse reflector to obtain a second image, wherein the second image includes an image of the second light spot; and the calibration device determining a second angle corresponding to the second laser based on the third pixel coordinates of the second target light point in the second image, the second target light point being determined based on the at least one second light point. Accordingly, S205 may include: the calibration device calibrating the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

[0167] In one possible implementation, the calibration device can employ a linear fitting method to linearly fit the first scale value, the first angle (i.e., the actual emission angle corresponding to the first laser), the second scale value, and the second angle (i.e., the actual emission angle corresponding to the second laser) to obtain a fitting equation. This fitting equation is used to indicate the correspondence between the laser emission angle and the code disk scale value. Based on this fitting equation, the scale value of the code disk corresponding to the laser with the emission angle of the target angle is determined.

[0168] For example, the calibration device performs a linear fit on the first scale value, the first angle, the second scale value, and the second angle to obtain, as shown below. Figure 8 The fitted line shown can be used to determine the scale value of the code disk corresponding to a laser with a emission angle of 0°, i.e., to determine... Figure 8 The zero value in the middle.

[0169] By using the calibration method 200 provided in this application and combining multiple sets of measurement data to calibrate the lidar, the calibration accuracy can be improved, thereby improving the measurement performance of the lidar.

[0170] Figure 9 A schematic flowchart of the calibration method 300 provided in an embodiment of this application is shown, such as... Figure 9 As shown, method 300 can be applied to Figure 3 and Figure 4 The system 100 described herein, the method 300 may include the following steps.

[0171] It should be noted that the parts not described in detail in method 300 can be referred to the relevant descriptions in method 200. To avoid repetition, they will not be repeated here.

[0172] S301. The lidar emits a first laser, the emission angle of which corresponds to a first scale value of the code disk inside the lidar, the first laser forms a first light spot on a first diffuse reflector plate, the first light spot including at least one first light point, and the first laser forms a third light spot on a second diffuse reflector plate, the third light spot including at least one third light point.

[0173] S302. The camera captures an image of the first diffuse reflector to obtain a first image, wherein the first image contains an image of the first light spot.

[0174] S303. The camera sends the first image to the calibration device; correspondingly, the calibration device receives the first image from the camera.

[0175] S304. The camera takes a picture of the second diffuser to obtain a third image, wherein the third image contains an image of a third light spot.

[0176] S305. The camera sends the third image to the calibration device; correspondingly, the calibration device receives the third image from the camera.

[0177] Optionally, S302 to S303 describe the process of the calibration device obtaining the first image, and S304 to S305 describe the process of the calibration device obtaining the third image. The two processes are independent of each other and are executed in no particular order.

[0178] S306. The calibration device determines the emission angle of the first laser as the first angle based on the first pixel coordinates of the first target light point in the first image and the fourth pixel coordinates of the third target light point in the third image, wherein the first target light point is determined based on the at least one first light point and the third target light point is determined based on the at least one third light point.

[0179] Optionally, prior to S306, the calibration device may determine the first target light spot based on the at least one first light spot; and determine the third target light spot based on the at least one third light spot. The specific process can be referred to the corresponding process in method 200, which will not be repeated here.

[0180] Specifically, in 306, the calibration device can determine the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; determine the third three-dimensional coordinates of the third target light point in the three-dimensional coordinate system of the lidar based on the fourth pixel coordinates; and determine the first angle based on the first three-dimensional coordinates and the third three-dimensional coordinates.

[0181] In one possible implementation, during the process of the calibration device determining the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates, the calibration device may first determine the first projection point of the reference point of the lidar's three-dimensional coordinate system on the first diffuse reflector; determine the second pixel coordinates of the first projection point in the first image; further, the calibration device may determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and a first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the lidar's three-dimensional coordinate system.

[0182] Similarly, in the process of determining the third three-dimensional coordinates of the third target light point in the three-dimensional coordinate system of the lidar based on the fourth pixel coordinates, the calibration device can first determine the second projection point of the reference point of the lidar's three-dimensional coordinate system on the second diffuse reflector; determine the fifth pixel coordinates of the second projection point in the third image; further, the calibration device can determine the third three-dimensional coordinates based on the fourth pixel coordinates, the fifth pixel coordinates, and the second distance, where the second distance represents the distance between the second diffuse reflector and the reference point of the lidar's three-dimensional coordinate system.

[0183] In one possible implementation, during the process of the calibration device determining the first angle based on the first three-dimensional coordinates and the third three-dimensional coordinates, the calibration device may first determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; then determine the fourth three-dimensional coordinates of the second projection point in the three-dimensional coordinate system of the lidar based on the second distance; furthermore, the calibration device determines the first angle based on the first three-dimensional coordinates, the second three-dimensional coordinates, the third three-dimensional coordinates, and the fourth three-dimensional coordinates.

[0184] For example, such as Figure 10 As shown, each pixel block in the first image and the third image (e.g.) Figure 10 The dimension of the symbol (indicated by "■") is P. size ×P size The first pixel coordinate of the first target light spot in the MON coordinate system is (M A1 N A1 The second pixel coordinate of the first projection point of the reference point in the coordinate system MON is (MA0 N A0 The first distance is d1, and the first target light point is in coordinate system O. L X L Y L Z L The first three-dimensional coordinate (x) LA1 ,y LA1 ,z LA1 ) is (d1, (M A1 -M A0 )×P size ,(N A1 -N A0 )×P size The first projection point is in coordinate system O. L X L Y L Z L The second three-dimensional coordinates (x) below LA0 ,y LA0 ,z LA0 Given (d1,0,0), the first angle θ corresponding to the first target light spot on the first diffuse reflector plate can be obtained based on the following formula 2. 1-1 .

[0185]

[0186] Similarly, the fourth pixel coordinate of the third target light spot in coordinate system M'O'N' is (M B1 N B1 The fifth pixel coordinate of the second projection point of this reference point in coordinate system M'O'N' is (M B0 N B0 The second distance is d2, and the third target light spot is in coordinate system O. L X L Y L Z L The third three-dimensional coordinate (x) LB1 ,y LB1 ,z LB1 ) is (d2, (M B1 -M B0 )×P size ,(N B1 -N B0 )×P size The second projection point is in coordinate system O. L X L Y L Z L The fourth three-dimensional coordinate (x) LB0 ,y LB0 ,z LB0Given (d2,0,0), the first angle θ corresponding to the third target light spot on the second diffuse reflector can be obtained based on the following formula 3. 1-2 .

[0187]

[0188] Since the first target light spot and the third target light spot are formed by the same beam of light (i.e., the first laser) emitted by the lidar on different diffuse reflectors, based on the parallelism of the first and second diffuse reflectors and the similarity of the light spots (or patches), it can be known that θ 1-1 =θ 1-2 =θ1.

[0189] The distance Δd between the first diffuse reflector and the second diffuse reflector can be expressed by the following formula 4, where Δd can be obtained by measuring with a total station.

[0190]

[0191] In summary, the first angle θ1 can be obtained by the following formula 5.

[0192]

[0193] The calibration method 300 provided in this application determines the first angle based on the light spot formed by the same laser on two parallel diffuse reflectors and the relative distance between the two diffuse reflectors, using the properties of similar triangles and geometric principles. This improves the calculation accuracy of the first angle and further enhances the calibration accuracy.

[0194] S307. The calibration device calibrates the lidar based on the first scale value and the first angle.

[0195] Optionally, the process of S307 can refer to the process of S205 above, and will not be repeated here.

[0196] The above combination Figures 5 to 10 The calibration method provided in the embodiments of this application has been introduced. The calibration device used to perform the above calibration method will be described below.

[0197] Figure 11 A schematic block diagram of a calibration device 400 provided in an embodiment of this application is shown. The device 400 can be applied to the calibration system 100 described above. Figure 11 As shown, the device 400 may include an acquisition unit 401 and a determination unit 402;

[0198] The acquisition unit 402 is used to acquire a first image, which is obtained by the camera taking a picture of the first diffuse reflector. The first image contains an image of a first light spot. The first light spot is formed on the first diffuse reflector by the first laser emitted by the lidar. The first light spot includes at least one first light point. The emission angle of the first laser corresponds to the first scale value of the internal code disk of the lidar.

[0199] The determining unit 402 is used to determine the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, wherein the first target light point is determined based on the at least one first light point; and to calibrate the lidar based on the first scale value and the first angle.

[0200] Furthermore, the determining unit 402 is specifically used to: determine the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates; and determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

[0201] Furthermore, the determining unit 402 is also used to determine the first projection point of the reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector; and to determine the second pixel coordinate of the first projection point in the first image; wherein, the determining unit 402 is specifically used to determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates and the first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

[0202] Furthermore, the determining unit 402 is also used to determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; wherein, the determining unit is specifically used to determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

[0203] Further, the determining unit 402 is specifically used to determine the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship, wherein the first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value; determine the angle deviation of the first laser based on the first angle and the third angle, wherein the angle deviation is the difference between the first angle and the third angle; determine the scale value offset of the code disk corresponding to the angle deviation; and determine the scale value of the code disk corresponding to the laser with an emission angle of the target angle based on the scale value offset.

[0204] Furthermore, the acquisition unit 401 is also used to acquire a second image, which is obtained by the camera taking a picture of the first diffuse reflector. The second image contains an image of a second light spot, which is formed on the first diffuse reflector by a second laser emitted by the lidar. The second light spot includes at least one second light point, and the emission angle of the second laser corresponds to the second scale value of the code disk in the lidar. The determination unit 402 is also used to determine the second angle corresponding to the second laser based on the third pixel coordinates of the second target light point in the second image. The second target light point is determined based on the at least one second light point. Specifically, the determination unit 402 is used by the calibration device to calibrate the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

[0205] Furthermore, the acquisition unit 401 is also used to acquire a third image, wherein the first laser forms a third light spot on the second diffuse reflector, the third light spot includes at least one third light point, and the third image is obtained by the camera taking a picture of the second diffuse reflector, the third image containing the third light spot; wherein, the determination unit 402 is specifically used to determine the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, and the third target light point is determined based on the at least one third light point.

[0206] Furthermore, the first three-dimensional coordinate is (x LAi ,y LAi ,z LAi The second three-dimensional coordinate is (x) LA0 ,y LA0 ,z LA0 ), wherein the determining unit 402 is specifically used to determine the first angle θ1 by the above formula (1).

[0207] Optionally, the device 400 may further include a first control unit 403 and / or a second control unit 404, wherein the first control unit 403 is used to control the lidar to emit the first laser; and the second control unit 404 is used to control the camera to capture the first diffuse reflector to obtain the first image.

[0208] Furthermore, the first control unit 403 is also used to control the lidar to emit the second laser; the second control unit 404 is also used to control the camera to capture the first diffuse reflector to obtain the second image.

[0209] Furthermore, the second control unit 404 is also used to control the camera to capture the second diffuser to obtain the third image.

[0210] It should be noted that the information interaction and execution process between the above-mentioned devices are based on the same concept as the method embodiments of this application. For details on their specific functions and technical effects, please refer to the method embodiments section, which will not be repeated here.

[0211] When using integrated units, device 400 may include a processor, a memory, and a communication module. The processor controls and manages the operation of device 400, for example, it can support device 400 in executing the steps performed by the aforementioned units. The memory can be used to store program code and data in device 400. The communication module can be used for communication between device 400 and other devices.

[0212] The processor can implement or execute various exemplary logic modules described in conjunction with the disclosure of this application. The processor can also be a combination of computing functions, such as including one or more microprocessor combinations, including a Central Processing Unit (CPU), and may also include other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. A general-purpose processor can be a microprocessor, a microcontroller, or any conventional processor.

[0213] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DR RAM).

[0214] The communication module can specifically be a radio frequency circuit, Bluetooth chip, Wi-Fi chip, or other device that interacts with other electronic devices.

[0215] This application also provides a computer-readable storage medium storing computer instructions. When the computer instructions are executed on a computer, the computer performs the aforementioned method steps to implement the calibration method in the above embodiments.

[0216] This application also provides a computer program product that, when run on a computer, causes the computer to perform the aforementioned related steps to implement the calibration method described in the above embodiments.

[0217] In addition, this application also provides an apparatus, which may specifically be a chip, component or module. The apparatus may include a coupled processor and a memory; wherein the memory is used to store computer execution instructions, and when the apparatus is running, the processor may execute the computer execution instructions stored in the memory to cause the chip to perform the above-mentioned calibration method.

[0218] In this application, the processor, computer-readable storage medium, computer program product or chip provided in the embodiments are all used to execute the corresponding methods provided above. Therefore, the beneficial effects that can be achieved can be referred to the beneficial effects in the corresponding methods provided above, and will not be repeated here.

[0219] Through the above description of the embodiments, those skilled in the art will understand that, for the sake of convenience and brevity, only the division of the above functional modules is used as an example. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

Claims

1. A calibration system, characterized in that, The system includes a camera, a lidar, a first diffuse reflector, and a calibration device. The lens of the camera and the viewing window of the lidar are both facing the direction of the first diffuse reflector, and the lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged parallel to each other. The lidar is used to emit a first laser, the emission angle of the first laser corresponds to the first scale value of the code disk inside the lidar, and the first laser forms a first light spot on the first diffuse reflector plate, the first light spot including at least one first light point. The camera is used to photograph the first diffuse reflector to obtain a first image, wherein the first image contains an image of the first light spot; The calibration device is used to determine the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, wherein the first target light point is determined based on the at least one first light point; and to calibrate the lidar based on the first scale value and the first angle.

2. The system according to claim 1, characterized in that, The calibration device is specifically used for: Based on the first pixel coordinates, the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar are determined; based on the first three-dimensional coordinates, the emission angle of the first laser is determined to be the first angle.

3. The system according to claim 2, characterized in that, The calibration device is also used to determine the first projection point of the reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector plate; and to determine the second pixel coordinates of the first projection point in the first image; Specifically, the calibration device is used to determine the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and the first distance, wherein the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

4. The system according to claim 3, characterized in that, The calibration device is also used to determine the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; Specifically, the calibration device is used to determine the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

5. The system according to any one of claims 1-4, characterized in that, The calibration device is specifically used for: Based on the first scale value and the preset first mapping relationship, the emission angle of the first laser is determined to be the third angle. The first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value. Based on the first angle and the third angle, the angle deviation of the first laser is determined, wherein the angle deviation is the difference between the first angle and the third angle; Determine the offset of the scale value of the code disk corresponding to the angle deviation; Based on the scale value offset, the scale value of the code disk corresponding to the laser with the emission angle of the target angle is determined.

6. The system according to any one of claims 1-4, characterized in that, The lidar is also used to emit a second laser, the emission angle of which corresponds to the second scale value of the code disk inside the lidar, and the second laser forms a second spot on the first diffuse reflector plate, the second spot including at least one second light point; The camera is also used to photograph the first diffuse reflector to obtain a second image, wherein the second image contains an image of the second light spot; The calibration device is further configured to determine the second angle corresponding to the second laser based on the third pixel coordinates of the second target light spot in the second image, wherein the second target light spot is determined based on the at least one second light spot; Specifically, the calibration device is used to calibrate the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

7. The system according to claim 6, characterized in that, The calibration device is specifically used for: Linear fitting is performed on the first scale value, the first angle, the second scale value, and the second angle to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value; Based on the fitted equation, the scale value of the encoder corresponding to the target angle is determined.

8. The system according to any one of claims 1-7, characterized in that, The system also includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third spot on the second diffuse reflector, and the third spot includes at least one third light point. The camera is also used to photograph the second diffuse reflector to obtain a third image, wherein the third image contains an image of a third light spot; Specifically, the calibration device is used to determine the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, wherein the third target light point is determined based on the at least one third light point.

9. The system according to claim 4, characterized in that, The calibration device is specifically used to determine the first angle using the following formula. , ,in, , ; Wherein, the first three-dimensional coordinates are ( ), the second three-dimensional coordinates are ( The coordinates of the first pixel are ( ). The second pixel coordinates are ( ), X LA1 = X LA0 = d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

10. The system according to any one of claims 1-9, characterized in that, The system also includes a total station, which is used to determine the location of each device.

11. A calibration method, characterized in that, The method is used to calibrate a system, the system including a camera, a lidar, a first diffuse reflector, and a calibration device. The lens of the camera and the viewing window of the lidar both face the direction of the first diffuse reflector, and the lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged parallel to each other. The method includes: The lidar emits a first laser, the emission angle of which corresponds to a first scale value of the internal code disk of the lidar, and the first laser forms a first light spot on the first diffuse reflector plate, the first light spot including at least one first light point. The camera captures an image of the first diffuse reflector to obtain a first image, wherein the first image contains an image of the first light spot; The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light spot in the first image, and the first target light spot is determined based on the at least one first light spot; The calibration device calibrates the lidar based on the first scale value and the first angle.

12. The method according to claim 11, characterized in that, The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: The calibration device determines the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates. The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

13. The method according to claim 12, characterized in that, The method further includes: The calibration device determines the first projection point of the reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector plate; The calibration device determines the second pixel coordinates of the first projection point in the first image; The calibration device determines the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates, including: The calibration device determines the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and the first distance, where the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

14. The method according to claim 13, characterized in that, The method further includes: The calibration device determines the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates, including: The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

15. The method according to any one of claims 11-14, characterized in that, The calibration device calibrates the lidar based on the first scale value and the first angle, including: The calibration device determines the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship. The first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value. The calibration device determines the angular deviation of the first laser based on the first angle and the third angle, wherein the angular deviation is the difference between the first angle and the third angle; The calibration device determines the offset of the scale value of the code disk corresponding to the angle deviation; The calibration device determines the scale value of the code disk corresponding to the laser with an emission angle equal to the target angle based on the scale value offset.

16. The method according to any one of claims 11-14, characterized in that, The method further includes: The lidar emits a second laser, the emission angle of which corresponds to the second scale value of the internal code disk of the lidar, and the second laser forms a second light spot on the first diffuse reflector plate, the second light spot including at least one second light point; The camera captures an image of the first diffuse reflector to obtain a second image, wherein the second image contains an image of the second light spot; The calibration device determines the second angle corresponding to the second laser based on the third pixel coordinates of the second target light spot in the second image, wherein the second target light spot is determined based on the at least one second light spot; The calibration device calibrates the lidar based on the first scale value and the first angle, including: The calibration device calibrates the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

17. The method according to claim 16, characterized in that, The calibration device calibrates the lidar based on the first scale value and the first angle, including: The calibration device performs linear fitting on the first scale value, the first angle, the second scale value, and the second angle to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value. The calibration device determines the scale value of the encoder corresponding to the target angle based on the fitting equation.

18. The method according to any one of claims 11-17, characterized in that, The system further includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third light spot on the second diffuse reflector, the third light spot including at least one third light point. The method further includes: The camera captures an image of the second diffuse reflector to obtain a third image, wherein the third image contains an image of the third light spot; The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: The calibration device determines the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, and the third target light point is determined based on the at least one third light point.

19. The method according to claim 14, characterized in that, The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates, including: determining the first angle using the following formula. , ,in, , ; Wherein, the first three-dimensional coordinates are ( ), the second three-dimensional coordinates are ( The coordinates of the first pixel are ( ). The second pixel coordinates are ( ), X LA1 = X LA0 = d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

20. The method according to any one of claims 11-19, characterized in that, The system also includes a total station, and the method further includes, before the lidar emits the first laser: The total station determines the location of each device.

21. A calibration method, characterized in that, The method is used for calibrating an apparatus, the apparatus for calibrating a system, the system further comprising a camera, a lidar, and a first diffuse reflector, wherein the lens of the camera and the viewing window of the lidar both face the direction of the first diffuse reflector, and the lens of the camera, the rear housing of the lidar, and the first diffuse reflector are arranged parallel to each other, the method comprising: The calibration device acquires a first image, which is obtained by the camera taking a picture of the first diffuse reflector. The first image contains an image of a first light spot, which is formed by the first laser emitted by the lidar on the first diffuse reflector. The first light spot includes at least one first light point, and the emission angle of the first laser corresponds to the first scale value of the internal code disk of the lidar. The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light spot in the first image, and the first target light spot is determined based on the at least one first light spot; The calibration device calibrates the lidar based on the first scale value and the first angle.

22. The method according to claim 21, characterized in that, The method further includes: The calibration device controls the lidar to emit the first laser; The calibration device controls the camera to capture images of the first diffuse reflector to obtain the first image.

23. The method according to claim 21 or 22, characterized in that, The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: The calibration device determines the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates. The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates.

24. The method according to claim 23, characterized in that, The method further includes: The calibration device determines the first projection point of the reference point of the three-dimensional coordinate system of the lidar on the first diffuse reflector plate; The calibration device determines the second pixel coordinates of the first projection point in the first image; The calibration device determines the first three-dimensional coordinates of the first target light point in the three-dimensional coordinate system of the lidar based on the first pixel coordinates, including: The calibration device determines the first three-dimensional coordinates based on the first pixel coordinates, the second pixel coordinates, and the first distance, where the first distance is the distance between the first diffuse reflector and the reference point of the three-dimensional coordinate system of the lidar.

25. The method according to claim 24, characterized in that, The method further includes: The calibration device determines the second three-dimensional coordinates of the first projection point in the three-dimensional coordinate system of the lidar based on the first distance; The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates, including: The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates.

26. The method according to any one of claims 21-25, characterized in that, The calibration device calibrates the lidar based on the first scale value and the first angle, including: The calibration device determines the emission angle of the first laser as a third angle based on the first scale value and a preset first mapping relationship. The first mapping relationship is used to indicate the correspondence between the laser emission angle and the code disk scale value. The calibration device determines the angular deviation of the first laser based on the first angle and the third angle, wherein the angular deviation is the difference between the first angle and the third angle; The calibration device determines the offset of the scale value of the code disk corresponding to the angle deviation; The calibration device determines the scale value of the code disk corresponding to the laser with an emission angle equal to the target angle based on the scale value offset.

27. The method according to any one of claims 21-25, characterized in that, The method further includes: The calibration device acquires a second image, which is obtained by the camera taking a picture of the first diffuse reflector. The second image contains a second light spot, which is formed on the first diffuse reflector by the second laser emitted by the lidar. The second light spot includes at least one second light point, and the emission angle of the second laser corresponds to the second scale value of the code disk in the lidar. The calibration device determines the second angle corresponding to the second laser based on the third pixel coordinates of the second target light spot in the second image, wherein the second target light spot is determined based on the at least one second light spot; The calibration device calibrates the lidar based on the first scale value and the first angle, including: The calibration device calibrates the lidar based on the first scale value, the first angle, the second scale value, and the second angle.

28. The method according to claim 27, characterized in that, The calibration device calibrates the lidar based on the first scale value and the first angle, including: The calibration device performs linear fitting on the first scale value, the first angle, the second scale value, and the second angle to obtain a fitting equation, which is used to indicate the correspondence between the laser emission angle and the code disk scale value. The calibration device determines the scale value of the encoder corresponding to the target angle based on the fitting equation.

29. The method according to any one of claims 21-28, characterized in that, The system further includes a second diffuse reflector, which is arranged parallel to the first diffuse reflector. The first laser forms a third light spot on the second diffuse reflector, the third light spot including at least one third light point. The method further includes: The calibration device acquires a third image, which is obtained by the camera taking a picture of the second diffuse reflector, and the third image contains an image of a third light spot. The calibration device determines the emission angle of the first laser as a first angle based on the first pixel coordinates of the first target light point in the first image, including: The calibration device determines the emission angle of the first laser as the first angle based on the first pixel coordinates and the fourth pixel coordinates of the third target light point in the third image, and the third target light point is determined based on the at least one third light point.

30. The method according to claim 25, characterized in that, The calibration device determines the emission angle of the first laser as the first angle based on the first three-dimensional coordinates and the second three-dimensional coordinates, including: determining the first angle using the following formula. , ,in, , ; Wherein, the first three-dimensional coordinates are ( ), the second three-dimensional coordinates are ( The coordinates of the first pixel are ( ). The second pixel coordinates are ( ), X LA1 = X LA0 = d1, where d1 is the first distance, P size Let be the side length of each pixel in the first image.

31. A calibration device, characterized in that, The method includes a memory and a processor, the memory storing computer program instructions, and the processor executing the computer program instructions to perform the method according to any one of claims 21-30.

32. A computer-readable storage medium, characterized in that, Used to store a computer program, which, when executed by a processor, implements the method as described in any one of claims 21-30.

33. A computer program product, characterized in that, When the computer program product is run on a processor, it implements the method as described in any one of claims 21-30.

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