A lidar calibration apparatus and method

Abstract

Embodiments of the present specification provide a laser radar calibration device and method. The device comprises: a light sensing apparatus configured to obtain a first light spot of a laser beam emitted by a laser radar to be calibrated in a measurement space, and generate a second light spot based on the first light spot; the size of the second light spot is smaller than the size of the first light spot; and a control module configured to determine a target position of the first light spot in a preset coordinate system based on the second light spot, and determine an actual exit angle of the laser beam based on at least the target position.

Description

TECHNICAL FIELD

[0001] The present specification relates to the field of laser technology, and in particular, to a laser radar calibration device and method. BACKGROUND

[0002] A laser radar detects the features of the environment and objects in a target range, such as the position (e.g., distance and angle), motion state (e.g., speed, vibration and attitude), and shape, by emitting laser to the target range or objects and receiving the reflected light of the objects. Due to the errors in the design, manufacture, etc. of mechanical components, the laser radar itself may have certain errors. The errors in the laser radar may cause the deviation of the data or information of the objects obtained when detecting the objects.

[0003] Therefore, it is desirable to provide a calibration device and method for a laser radar. SUMMARY

[0004] One aspect of the present specification provides a laser radar calibration device. The device comprises: a light sensing apparatus configured to obtain a first light spot of a laser beam emitted by a laser radar to be calibrated in a measurement space, and generate a second light spot based on the first light spot; the size of the second light spot is smaller than the size of the first light spot; and a control module configured to determine a target position of the first light spot in a preset coordinate system based on the second light spot, and determine an actual exit angle of the laser beam based on at least the target position.

[0005] In some embodiments, the light sensing apparatus comprises: an incident light end configured to receive at least part of a light signal of the first light spot; an exit light end configured to output the light signal and generate the second light spot; and a light sensing portion configured to sense the second light spot to obtain a first position of the second light spot in the light sensing apparatus.

[0006] In some embodiments, the light sensing apparatus covers the measurement space along a first direction; the device further comprises a guide rail arranged in the measurement space, and the light sensing apparatus is mounted on the guide rail; the light sensing apparatus is capable of moving in a second direction of the measurement space along the guide rail; and the second direction is perpendicular to the first direction.

[0007] In some embodiments, to determine the target position of the second light spot in the preset coordinate system, the control module is further configured to: obtain a first position of the second light spot in the light sensing device, determine a first coordinate based on the first position, a coordinate axis of the first coordinate being parallel to the first direction; obtain a second position of the light sensing device corresponding to the second light spot on the guide rail, determine a second coordinate based on the second position, a coordinate axis of the second coordinate being parallel to the second direction; and determine the target position of the first light spot in the preset coordinate system based on the first coordinate and the second coordinate.

[0008] In some embodiments, a clamp for carrying the laser radar to be calibrated is further included, the clamp being configured to be movable relative to the measurement space along a third direction, the third direction being perpendicular to the first direction and the second direction.

[0009] Another aspect of the present specification provides a laser radar calibration method. The method comprises: obtaining, by a light sensing device, a first light spot of a laser beam emitted by a laser radar to be calibrated in a measurement space; generating a second light spot based on the first light spot in the light sensing device, a size of the second light spot being smaller than a size of the first light spot; determining a target position of the first light spot in a preset coordinate system based on the second light spot; and determining an actual exit angle of the laser beam based on the target position.

[0010] In some embodiments, the obtaining, by the light sensing device, the first light spot of the laser beam in the measurement space comprises: moving the light sensing device along a second direction in the measurement space to obtain the first light spot of the laser beam in the measurement space; wherein the light sensing device covers the measurement space along a first direction; and the second direction is perpendicular to the first direction.

[0011] In some embodiments, the determining the target position of the first light spot in the preset coordinate system based on the second light spot comprises: obtaining a first position of the second light spot in the light sensing device, determining a first coordinate based on the first position, a coordinate axis of the first coordinate being parallel to the first direction; obtaining a second position of the light sensing device corresponding to the second light spot on the guide rail, determining a second coordinate based on the second position, a coordinate axis of the second coordinate being parallel to the second direction; and determining the target position of the first light spot in the preset coordinate system based on the first coordinate and the second coordinate.

[0012] In some embodiments, the light sensing device comprises an incident light end, an outgoing light end, and a light sensing part; the obtaining the first position of the second light spot in the light sensing device comprises: receiving at least part of the light signal of the first light spot through the incident light end; outputting the light signal through the outgoing light end and generating the second light spot; and sensing the second light spot through the light sensing part to obtain the first position of the second light spot in the light sensing device. BRIEF DESCRIPTION OF DRAWINGS

[0013] The present specification will be further described in the manner of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not restrictive, and in these embodiments, the same numbers represent the same structures or operations, in which:

[0014] Figure 1 is a schematic diagram of an exemplary laser radar calibration device shown according to some embodiments of the present specification;

[0015] Figure 2 is a scene schematic diagram of a space center origin determined by an origin determination module shown according to some embodiments of the present specification;

[0016] Figure 3 is a schematic diagram of an exemplary light sensing device shown according to some embodiments of the present specification;

[0017] Figure 4A is a schematic diagram of a first light spot obtained by a light sensing device shown according to some embodiments of the present specification;

[0018] Figure 4B is a schematic diagram of a second light spot obtained by a light sensing device shown according to some embodiments of the present specification;

[0019] Figure 5 is a flowchart of a laser radar calibration method shown according to some embodiments of the present specification;

[0020] Figure 6 is a schematic diagram of an exemplary laser radar calibration method shown according to some embodiments of the present specification. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some examples or embodiments of the present specification, and for those skilled in the art, the present specification can also be applied to other similar scenarios without creative labor. Unless it is obvious from the language environment or otherwise stated, the same numbers in the drawings represent the same structure or operation.

[0022] It should be understood that the use of “system,” “apparatus,” “unit,” and / or “module” herein is merely used to differentiate different components, elements, parts, sections, or assemblies at different levels. However, if other words can achieve the same purpose, the words can be replaced by other expressions.

[0023] As indicated in the specification and claims, unless the context clearly indicates otherwise, the words “a,” “an,” “the,” and / or “this” are not limited to the singular form but can include the plural form as well. Generally, the terms “include” and “comprise” merely indicate the inclusion of the elements explicitly identified, and these elements do not constitute an exhaustive list of steps or elements that can be included in the method or apparatus.

[0024] Although the present specification makes various references to certain modules or units in the system according to the embodiments of the present specification, any number of different modules or units can be used and run on the client and / or server. The modules are merely illustrative, and different aspects of the system and method can use different modules.

[0025] Flowcharts are used in the present specification to illustrate the operations performed by the system according to the embodiments of the present specification. It should be understood that the preceding or subsequent operations are not necessarily performed in sequence. Instead, the steps can be processed in reverse order or simultaneously. Other operations can also be added to these processes, or one or more steps can be removed from these processes.

[0026] The laser radar can detect the characteristics of the environment and objects in the target range by emitting laser to the target range or objects and receiving the reflected light of the objects, and the detection accuracy reflects the level of accurately detecting the environment of the target range. For example, in the scene of unmanned driving, the laser radar can detect the characteristics such as the position and speed of the objects around the vehicle by emitting laser to the objects around the unmanned vehicle and receiving the reflected light of the objects, and then provide environmental information for the automatic driving strategy. If there is a large detection error of the laser radar, not only the implementation of the automatic driving strategy of the vehicle will be affected, but also the safety of the vehicle driving will be a great hidden danger. By calibrating the laser radar, the actual emission angle of the laser radar at the set emission angle can be determined, so as to verify whether the emission angle of the laser radar is accurate. Further, the deviation between the set emission angle and the actual emission angle of the laser radar can be determined, the corresponding relationship between the set emission angle and the actual emission angle is established, and the deviation is compensated based on the corresponding relationship, so as to calibrate the detection result of the laser radar to the object.

[0027] In some embodiments, the laser radar calibration device can acquire an image of a light spot of a laser beam emitted by the laser radar to be calibrated through a camera, and determine the actual exit angle of the laser beam based on the pixel coordinates of the light spot in the image. It is considered that the shooting field of view and the edge imaging distortion of the camera are usually a pair of contradictions. If a wide-angle camera lens is used in order to cover a sufficient shooting field of view, the edge of the shot light spot image can be geometrically distorted, which affects the calculation of the actual exit angle of the laser beam. The embodiments of the present specification provide a laser radar calibration device, which uses a light sensing device instead of a camera to acquire a light spot, can obtain a light signal with clear boundaries, so as to accurately determine the position and size of the light spot, and further improve the precision and accuracy of laser radar calibration. In some embodiments, the light sensing device can include a PSD sensor, the spectral response of the PSD sensor is wide, which can cover most of the wave bands of the laser beam, improve the light signal acquisition strength, and the PSD sensor has high resolution, which can further improve the precision and accuracy of laser radar calibration. In some embodiments, the PSD sensor is arranged in the light sensing device, and the light sensing device further includes an optical fiber, an incident light end and an emergent light end. After the incident light end acquires a first light spot, the first light spot is converted into a second light spot with smaller size through the emergent light end. Therefore, in the case that the size of the PSD sensor is small, the field of view of the laser radar can also be covered, the complete and clear light spot can be acquired, and the accuracy of the calibration result is improved.

[0028] It should be understood that the application scenarios of the laser radar calibration device of the embodiments of the present specification are only some examples or embodiments of the present specification, and for those skilled in the art, the embodiments of the present specification can also be applied to other similar scenarios without creative labor according to the drawings. For example, the calibration device can also be applied to calibrate other laser devices, such as infrared laser emitters, X-ray emitters, etc., and the present specification is not limited to this.

[0029] Figure 1 is a schematic diagram of an exemplary laser radar calibration device according to some embodiments of the present specification.

[0030] As Figure 1 shown, the laser radar calibration device 100 can include a laser radar 110 to be calibrated and a light sensing device 120.

[0031] The laser radar to be calibrated 110 can be configured to emit laser beams. In some embodiments, the laser radar to be calibrated 110 can emit laser beams at different horizontal deflection angles and vertical deflection angles. The horizontal deflection angle refers to the deflection angle in the horizontal direction, and the vertical deflection angle refers to the deflection angle in the vertical direction. For example, the laser radar can emit laser beams at -30 degrees to +10 degrees in the vertical direction, or -45 degrees to +45 degrees in the horizontal direction. In some embodiments, the laser radar to be calibrated 110 can include, but is not limited to, a pulsed laser radar, a continuous wave laser radar, and the like.

[0032] In some embodiments, the laser beams emitted by the laser radar to be calibrated 110 can form first light spots 126 in the measurement space 130. In some embodiments, the first light spots 126 can be spot-shaped images formed by the laser beams emitted by the laser radar to be calibrated 110 in the measurement space 130. In some embodiments, the first light spots 126 can be regular-shaped figures, such as circles, ellipses, squares, and the like. In some embodiments, the first light spots 126 can also be irregular-shaped figures. In some embodiments, the laser radar to be calibrated 110 can emit a single laser beam to form one first light spot 126. In some embodiments, the laser radar to be calibrated 110 can emit multiple laser beams to form multiple first light spots 126, for example, the laser radar to be calibrated 110 can emit three laser beams at the same time, and the laser beams form three first light spots 126 in the measurement space 130, respectively. In some embodiments, the first light spots 126 can be formed on a projection plane in the measurement space 130.

[0033] The measurement space 130 refers to a space that can cover the scanning range (Field of View, FOV) of the laser radar 110 to be calibrated. The scanning range of the laser radar refers to the range of the exit angle of the laser beam that the laser radar can emit. For example, the laser radar can emit a laser beam of-30 degrees to +10 degrees in the vertical direction and a laser beam of-45 degrees to +45 degrees in the horizontal direction, and the corresponding scanning range is 90 degrees horizontally and 40 degrees vertically. In some embodiments, the measurement space 130 can include a projection plane. In some embodiments, the projection plane can be a plane perpendicular to the actual exit angle of 0° of the laser beam emitted by the laser radar to be calibrated, which is intercepted in the measurement space 130. In some embodiments, the projection plane can be a reflecting surface of a reflecting object such as a base, a curtain, a stand, an imaging screen, etc. set in the measurement space 130. In some embodiments, the projection plane can also be a preset virtual plane. In some embodiments, the size of the coverage area of the projection plane is associated with the distance between the laser radar to be measured and the projection plane. For example, the smaller the distance between the laser radar to be measured and the projection plane, the smaller the coverage range of the corresponding projection plane. In some embodiments, the size of the coverage area of the projection plane can be adjusted in real time according to the scanning range of the laser radar 110 to be calibrated, which is not limited in the present specification.

[0034] In some embodiments, the laser radar calibration device 100 can further include a clamp 150 for carrying the laser radar 110 to be calibrated. In some embodiments, the clamp 150 can also adjust the position of the laser radar 110 to be calibrated in space. In some embodiments, the clamp 150 can adjust the laser radar 110 to be calibrated to a calibration position, where the calibration position can be a pre-set position. In some embodiments, when the laser radar 110 to be calibrated is located at the calibration position, the emitted laser beam can be projected onto the projection plane.

[0035] In some embodiments, the clamp 150 can include components such as an adjusting mechanism for adjusting the spatial position of the laser radar 110 to be calibrated to move to a calibration position, and a fixing mechanism for fixing the installation of the laser radar 110 to be calibrated to maintain the position and stability of the laser radar 110 to be calibrated. In some embodiments, the adjusting mechanism of the clamp 150 can include a first moving part and a second moving part, the first moving part can move in a first direction, and the second moving part can move in a second direction, wherein the first direction and the second direction are perpendicular to each other. In some embodiments, the first direction and the second direction can be parallel to the projection plane, and then the offset position of the laser radar 110 to be calibrated relative to the projection plane can be adjusted by adjusting the first moving part and the second moving part. In some embodiments, the clamp 150 is arranged to be movable in a third direction relative to the measurement space 130, wherein the third direction can be perpendicular to the first direction and the second direction, i.e. perpendicular to the projection plane. In some embodiments, since the emission range of the laser beam of the laser radar 110 to be calibrated is conical diffusion, the clamp 150 can change the vertical distance between the laser radar 110 to be calibrated and the projection plane when moving in the third direction, so as to adjust the projection range of the laser radar 110 to be calibrated in the projection plane. By adjusting the offset position and the projection range of the laser radar 110 to be calibrated, the laser beam emitted by the laser radar 110 to be calibrated can be projected into the preset range (such as the projection range) of the projection plane, facilitating subsequent calibration operations.

[0036] In some embodiments, the laser radar 110 to be calibrated can also be directly placed on a desktop, a support table or other objects that can raise the height of the laser radar, and the laser radar 110 to be calibrated is fixed in the calibration position by the objects.

[0037] In some embodiments, the laser radar calibration device 100 can further include a base 160. In some embodiments, the base 160 can be arranged on the projection plane. In some embodiments, the laser beam can be projected on the base 160 to form the first light spot 126. In some embodiments, the area of the projection plane can be greater than, less than or equal to the area of the base 160. In some embodiments, the light sensing device 120 can be arranged in the projection plane, and the base 160 can serve as a support for supporting the light sensing device 120. In some embodiments, the laser beam can also be projected on the light sensing device 120 to form the first light spot 126. In some embodiments, the base 160 can be configured in a flat plate shape to facilitate the maintenance of the light sensing device 120 in the projection plane.

[0038] In some embodiments, the projection range of the laser beams of the laser radar to be calibrated 110 on the measurement space 130 can be limited within the coverage of the base 160. For example, the vertical distance between the laser radar to be calibrated 110 and the projection plane can be adjusted by adjusting the position of the clamp 150 to change the coverage size of the projection range. The vertical distance can be the distance between the laser radar to be calibrated 110 and the base 160 in the third direction. In some embodiments, assuming that the length of the base 160 in the horizontal direction is 2 meters and the scanning range of the laser radar to be calibrated 110 in the horizontal direction is -45 degrees to +45 degrees, the vertical distance between the laser radar to be calibrated 110 and the base 160 should be less than or equal to 1 meter, so that the projection range of the laser radar to be calibrated 110 can fall within the coverage of the base 160.

[0039] In some embodiments, the laser radar calibration device 100 can further include a base 170 for supporting components such as the clamp 150, the laser radar to be detected, etc. In some embodiments, the base 160 and the base 170 can be arranged perpendicular to each other, facilitating the laser radar to be detected to project the laser beams onto the base 160. In some embodiments, the base 160 and the base 170 can be arranged in any suitable orientation, for example, the base 160 can be arranged in a vertical plane and the base 170 can be arranged in a horizontal plane, but the present specification does not limit this. In some embodiments, the base 170 can be a dedicated flat platform 190, or the upper surface of a table top or other support surface.

[0040] In some embodiments, the light sensing device 120 includes a collection part 121 and a light sensing part 122, the collection part 121 is used to collect the light signals of the light spots (e.g., the first light spot 126) in the projection plane and transmit the light signals to the light sensing part 122, and the light sensing part 122 is used to sense the light signals of the light spots on its surface transmitted by the collection part 121 and convert the light signals into required electrical signals. In some embodiments, the collection part 121 includes an incident light end 123 and an outgoing light end 124, the incident light end 123 can be an end surface for receiving the light signals of the light spots in the projection plane, and the outgoing light end 124 can be an end surface for outputting the light signals to the light sensing part 122. For specific details of the light sensing device 120, please refer to the related description below. Figure 3

[0041] ​In some embodiments, the light sensing device 120 can be used to acquire the first light spot 126 of the laser beam emitted by the laser radar 110 to be calibrated in the measurement space 130, and generate the second light spot 127 based on the first light spot 126. In some embodiments, the light sensing device 120 can also serve as a reflecting object of the first light spot 126, that is, the laser beam of the laser radar 110 to be calibrated can form the first light spot 126 on the surface of the light sensing device 120. In some embodiments, the incident light end 123 of the collection unit 121 can acquire the first light spot 126 formed on the surface of the light sensing device 120. The collection unit 121 can transmit the light signal of the first light spot 126 to the outgoing light end 124 and project it to the photosensitive unit 122 to form the second light spot 127. The photosensitive unit 122 can convert the light signal of the second light spot 127 into an electrical signal, and then determine the position of the second light spot 127 on the photosensitive unit 122.

[0042] In some embodiments, the collection range of the light sensing device 120 can be greater than, less than, or equal to the projection range of the projection plane. The collection range of the light sensing device refers to the range that can be collected by the light sensing device 120 in a static state. In some embodiments, if the collection range of the light sensing device 120 is less than the projection range of the projection plane, the light sensing device 120 can be arranged on the base 160 by a moving mechanism, which can drive the light sensing device 120 to move within the projection range and acquire the first light spot 126 within the projection range. In some embodiments, if the collection range of the light sensing device 120 is greater than or equal to the projection range of the projection plane, the light sensing device 120 can be fixedly connected with the base 160, for example, the light sensing device 120 can cover the entire projection range.

[0043] In some embodiments, the photosensitive device 120 can cover the measurement space 130 along the first direction, that is, the photosensitive device 120 completely covers the projection range along the first direction on the projection plane in the measurement space 130. In some embodiments, the photosensitive device 120 can be constructed in the shape of a long strip extending along the first direction. In some embodiments, the first direction can be a horizontal direction. In some embodiments, the first direction can also be a vertical direction. In some embodiments, the first direction can be a direction at any angle within the projection plane, and this specification does not limit this. In some embodiments, the incident light end 123 of the photosensitive device 120 can include a plurality of incident ports 1231 that allow light to enter, and the incident ports 1231 of the incident light end 123 are arranged at intervals along the first direction and cover the measurement space 130. In this way, the position of the incident port 1231 of the incident light end 123 can be used to characterize position information in the first direction, such as coordinate information in the first direction. In some embodiments, when the photosensitive device 120 obtains the first light spot 126, the first light spot 126 can cover the incident port 1231 of at least one incident light end 123. The incident port 1231 of the incident light end 123 transmits the light signal of the first light spot 126 to the corresponding output light end 124, and projects it to the photosensitive part 122. The photosensitive device 120 can determine the position information of the incident port 1231 of the incident light end 123 covered by the first light spot 126 based on the signal sensed by the photosensitive part 122, and can further determine the coordinate information of the first light spot 126 in the first direction based on the position information.

[0044] In some embodiments, the photosensitive device 120 can be movably set on the base 160 through a moving mechanism, and the moving mechanism can drive the photosensitive device 120 to move along a second direction, wherein the second direction is perpendicular to the first direction, so that the photosensitive device 120 covers the entire projection range within the projection plane through movement.

[0045] In some embodiments, the laser radar calibration device 100 can further comprise a movement controller. In some embodiments, the movement controller can be used to control the movement of the movement mechanism. In some embodiments, the movement controller can acquire the position information of the movement mechanism along the second direction. In some embodiments, the movement controller can acquire the movement time and movement speed of the movement mechanism, and further calculate the position information of the movement mechanism along the second direction. For example, in the process of the movement mechanism moving along the second direction from the initial position, the movement controller can acquire the movement time of the light sensing device 120 scanning the first light spot 126, and calculate the distance of the movement mechanism relative to the initial position at this time by combining the movement time of the movement mechanism, so as to calculate the position coordinate of the first light spot 126 along the second direction. In some embodiments, if the size of the first light spot 126 is large, the movement controller can acquire the initial time when the light sensing device 120 first collects the first light spot 126, and the end time when the light sensing device 120 stops collecting the first light spot 126 after the movement mechanism passes through the first light spot 126, and calculate the position coordinate of the center of the first light spot 126 by the time difference between the initial time and the end time and the speed of the movement mechanism. This calculation method has high accuracy and can improve the calibration accuracy of the laser radar to be calibrated 110.

[0046] In some embodiments, the laser radar calibration device 100 can further comprise a guide rail 180 arranged in the measurement space 130, and the light sensing device 120 can be installed on the guide rail 180. The guide rail 180 can be used to provide a movement track for the light sensing device 120 to move in the projection plane. In some embodiments, the guide rail 180 can be arranged linearly along the first direction and / or the second direction. In some embodiments, if the light sensing device 120 covers the measurement space 130 along the first direction, in order to measure the position coordinate of the first light spot 126 along the second direction, the guide rail 180 can be arranged linearly along the second direction, and the light sensing device 120 can move along the guide rail 180 in the second direction of the measurement space 130, wherein the second direction is perpendicular to the first direction. In some embodiments, if the light sensing device 120 covers the measurement space 130 along the second direction, the guide rail 180 can be arranged linearly along the first direction, and the light sensing device 120 can move along the guide rail 180 in the first direction of the measurement space 130.

[0047] In some embodiments, the guide rail 180 can be used to position the coordinate of the light sensing device 120. In some embodiments, a position sensor can be laid on the guide rail 180, which can determine the position of the light sensing device 120. In some embodiments, an end of the guide rail 180 can be provided with a range finder, which can determine the position of the light sensing device 120. In some embodiments, the guide rail 180 can be provided with a driving device, such as a motor or a linear telescopic cylinder, and the position of the light sensing device 120 can be calculated according to the operating parameters and time of the driving device. For example, the moving speed and moving time of the light sensing device 120 on the guide rail 180 can be determined by the rotating speed of the motor, so as to determine the position of the light sensing device 120, or the position of the light sensing device 120 on the guide rail 180 can be determined by the telescopic length of the linear telescopic cylinder.

[0048] In some embodiments, the light sensing device 120 can be directly slidably matched with the guide rail 180, which means that the light sensing device 120 can slide along the guiding direction of the guide rail 180. In some embodiments, the guide rail 180 can be a groove-shaped track arranged on the base 160, and the light sensing device 120 can be matched in the groove-shaped track through a sliding block or a roller. In some embodiments, the guide rail 180 can be a convex rail protruding from the base 160, and the light sensing device 120 can be matched on the convex rail through a concave rail or a guide groove.

[0049] In some embodiments, the light sensing device 120 can be installed on the guide rail 180 through a moving mechanism. In some embodiments, the moving mechanism can include a carrier 190 and a driving mechanism. The carrier 190 is arranged between the guide rail 180 and the light sensing device 120, and is used to carry and support the light sensing device 120, and can move along the guide rail 180. The driving mechanism is used to drive the carrier 190 to move. In some embodiments, the driving mechanism can include but is not limited to a motor or a linear telescopic cylinder. In some embodiments, the driving mechanism can be controlled by a moving controller. In some embodiments, the number of the guide rails 180 is two, and the two guide rails 180 are arranged in parallel along the second direction. The two ends of the carrier 190 are matched with the two guide rails 180 respectively, which can improve the stability of the movement of the carrier 190.

[0050] In some embodiments, the light sensing device 120 can be multiple, each of which can be configured as a long strip and cover the measurement space 130 along the first direction. The multiple light sensing devices 120 can be adjacently arranged along the second direction and cover the entire base 160. The plane formed by the multiple light sensing devices 120 can be the projection plane of the laser radar 110 to be calibrated, and the laser beam of the laser radar 110 to be calibrated is projected onto the projection plane to form the first light spot 126. In some embodiments, if the first light spot 126 is small and one light sensing device 120 can completely obtain the entire first light spot 126, the light sensing device 120 can determine the position coordinates of the first light spot 126 along the first direction, and the position of the first light spot 126 along the second direction can be determined according to the position of the light sensing device 120 arranged along the second direction. In some embodiments, if the first light spot 126 is large and multiple light sensing devices 120 are needed to obtain the complete first light spot 126, the position of the first light spot 126 along the first direction can be calculated according to the positions of the light signals collected by the multiple light sensing devices 120. For example, the light sensing device 120 that covers the largest area of the first light spot 126 along the first direction can be determined, and the position of the first light spot 126 along the first direction can be determined according to the light sensing device 120. According to the position coordinates of the multiple light sensing devices 120 arranged, the midpoint is taken as the position of the first light spot 126 along the second direction.

[0051] In some embodiments, the light sensing device 120 can be configured as a two-dimensional pattern along the first direction and the second direction, for example, the light sensing device 120 can be configured as a rectangle, a circle, etc., but is not limited thereto. In some embodiments, the light sensing device 120 can cover the entire projection plane, i.e., the incident light end 123 of the light sensing device 120 covers the entire projection plane (such as the base 160), and the incident light end 123 is provided with multiple arrayed incident ports 1231. The incident ports 1231 are arranged according to a predetermined pitch, and each incident port 1231 corresponds to an exit port 1241 of an exit light end 124. After the first light spot 126 is formed on the incident light end 123, the coordinate position of the first light spot 126 can be determined according to the information of the incident port 1231 of the light sensing device 120 that obtains the first light spot 126.

[0052] In some embodiments, the two-dimensional pattern of the light sensing device 120 can be smaller than the projection plane. In some embodiments, the light receiving end 123 of the light sensing device 120 can be provided with a plurality of rows and columns of light receiving ports 1231, or the light receiving end 123 can be provided with a plurality of layers of circular ring radiation light receiving ports 1231, or the light receiving end 123 can be provided with only one light receiving port 1231. In some embodiments, the light sensing device 120 can be arranged on the base 160 by a moving mechanism capable of driving the light sensing device 120 to move in full coverage scanning in the projection plane (i.e., capable of moving in both the first direction and the second direction), and a moving controller can obtain the coordinates of the moving mechanism in the first direction and the coordinates of the moving mechanism in the second direction on the base 160, and combine the information of the light receiving port 1231 on the light sensing device 120 that obtains the first light spot 126 to calculate the specific position of the first light spot 126.

[0053] In some embodiments, after the light receiving end 123 of the light sensing device 120 obtains the first light spot 126, the light signal is projected to the light sensing portion 122 by the light emitting end 124 to form a second light spot 127, and the size of the second light spot 127 can be smaller than the size of the first light spot 126. In some embodiments, the size of the light spot can be the area of the light spot, for example, the area of the second light spot 127 can be smaller than the area of the first light spot 126. In some embodiments, the size of the light spot can be the length dimension of the light spot in a preset direction, wherein the preset direction can be the first direction, the second direction, or other directions, etc. In some embodiments, the light sensing device 120 covers the measurement space 130 in the first direction, and the size of the light spot can be the length dimension of the light spot in the first direction, and by determining the length dimension information of the second light spot 127 in the first direction obtained by the light sensing portion 122, the position coordinates of the first light spot 126 in the first direction can be calculated. In some embodiments, the shape of the first light spot 126 and / or the second light spot 127 can include but is not limited to various shapes such as a circle, a square, a pentagon, an ellipse, or an irregular shape, etc. In some embodiments, the size of the light spot can be measured by the length dimension of the preset direction or the area of the light spot, but the present specification does not limit this.

[0054] In some embodiments, the size of the second light spot 127 can be equal to the size of the first light spot 126, for example, the light sensing portion 122 of the light sensing device 120 can directly serve as the projection plane of the laser beam, and at this time, the first light spot 126 and the second light spot 127 can be the same light spot.

[0055] In some embodiments, the lidar calibration device 100 can further include a control module, which can be used to control and / or schedule various components in the lidar calibration device 100, such as the clamp 150, the moving mechanism, the light sensing device 120, etc. In some embodiments, the control module can include, but is not limited to, a programmable chip, a desktop computer, a notebook computer, a mobile phone terminal, an iPad terminal, etc.

[0056] In some embodiments, the control module can be used to determine the target position of the first light spot 126 in the preset coordinate system based on the second light spot 127. Specifically, the light sensing part 122 of the light sensing device 120 can acquire the second light spot 127 and generate a corresponding electrical signal, the control module can acquire the electrical signal and convert it into a digital signal, and determine the target position of the first light spot 126 in the preset coordinate system according to the digital signal.

[0057] In some embodiments, the preset coordinate system can be determined based on the positions of the light sensing device 120 and the lidar to be calibrated 110, and the preset coordinate system can be a spatial three-axis coordinate system. For example, the preset coordinate system can include a spatial center origin O, X-axis, Y-axis and Z-axis which are perpendicular to each other. In some embodiments, the spatial center origin O can be arranged in the projection plane where the light sensing device 120 is located. In some embodiments, the preset coordinate system can take a first direction in the projection plane as the Y-axis and a second direction as the X-axis. In some embodiments, the first direction can be a vertical direction and the second direction can be a horizontal direction. In some embodiments, in the measurement space 130, the Z-axis is perpendicular to the first direction and the second direction, such as taking a third direction as the Z-axis. In some embodiments, the light sensing device 120 can be arranged in a two-dimensional plane (such as XOY plane) formed by the X-axis and the Y-axis in the preset coordinate system.

[0058] In some embodiments, the spatial center origin O is the mapping position of the laser beam on the receiving screen when the actual exit angle of the laser beam is 0 degrees. In some embodiments, the spatial center origin O of the lidar to be calibrated 110 can be determined by the origin determination module 140.

[0059] Figure 2 is a scene diagram for determining the spatial center origin of the origin determination module according to some embodiments of the present specification. In some embodiments, as shown in FIG. 13A, the light sensing device 120 can be arranged in the XOY plane of the preset coordinate system, and the spatial center origin O of the lidar to be calibrated 110 can be determined by the origin determination module 140. Figure 2As shown, the position of the origin determination module 140 is adjusted so that the meridian circle J projected by the origin determination module 140 is perpendicular to the horizontal reference line, and one intersection point P of the meridian circle J and the parallel circle W projected by the origin determination module 140 coincides with the laser outlet S of the laser radar 110 to be calibrated, the position of the other intersection point Q of the meridian circle J and the parallel circle W projected by the origin determination module 140 in the base plane can be defined as the spatial center origin O of the laser radar to be calibrated, and the position information of the intersection point Q is the position information of the spatial center origin O.

[0060] In some embodiments, the control module can obtain a target position of the first light spot 126 in a preset coordinate system. The target position refers to the actual coordinate position of the first light spot 126 in the preset coordinate system. For example, the coordinates of the target position can be determined as (x, y, 0) based on the distances of the first light spot 126 from the spatial center origin O on the X-axis and the Y-axis, respectively.

[0061] In some embodiments, the control module can obtain a first position of the second light spot 127 in the light sensing device 120, and determine a first coordinate based on the first position. In some embodiments, the first coordinate can be a coordinate corresponding to the Y-axis in the preset coordinate system. In some embodiments, the first position can be a coordinate position determined based on a coordinate system preset on the light sensing portion 122. In some embodiments, the coordinate system on the light sensing portion 122 can be a one-dimensional coordinate system. In some embodiments, the coordinate system on the light sensing portion 122 can also be a two-dimensional coordinate system. In some embodiments, the coordinate system on the light sensing portion 122 can establish a mapping relationship with the preset coordinate system, and based on the mapping relationship, the first coordinate of the first light spot 126 in the preset coordinate system can be determined through the first position of the second light spot 127. For details, please refer to Figure 4A and related descriptions thereof.

[0062] In some embodiments, the control module can obtain a second position of the light sensing device 120 corresponding to the second light spot 127 on the guide rail 180, and determine a second coordinate based on the second position. In some embodiments, the second coordinate can be a coordinate corresponding to the X axis in the preset coordinate system. In some embodiments, the light sensing device 120 moves in the second direction on the guide rail 180, and the control module can determine the second position of the light sensing device 120 on the guide rail 180 according to the moving speed, moving time and moving direction of the light sensing device 120. In some embodiments, the control module can determine the coordinate value of the starting point of the light sensing device 120 on the guide rail 180 on the X axis, calculate the moving distance of the light sensing device 120 in the second direction according to the moving speed and moving time of the light sensing device 120, and calculate the second coordinate of the light sensing device 120 according to the coordinate value of the starting point, the positional relationship between the origin and the starting point, and the moving distance of the light sensing device 120. In some embodiments, the control module can also determine the second position of the light sensing device 120 according to the signal of the position detector arranged on the guide rail 180. For example, the position detector can be arranged at the coordinate origin of the preset coordinate system, and the position detector can directly measure the distance between the light sensing device 120 and the coordinate origin in the second direction, which can be used as the second coordinate.

[0063] In some embodiments, the control module can determine the target position of the first light spot 126 in the preset coordinate system based on the first coordinate and the second coordinate. In some embodiments, the target position of the first light spot 126 in the preset coordinate system can be represented as a coordinate point (x, y, 0) in the preset coordinate system. In some embodiments, the x coordinate of the target position of the first light spot 126 is the second coordinate, and the y coordinate is the first coordinate. For example, the first coordinate is 5, and the second left edge is 6, and the target position of the first light spot 126 in the preset coordinate system is (6, 5, 0).

[0064] In some embodiments, the control module can also determine the actual exit angle of the laser beam based on at least the target position. The actual exit angle refers to the included angle between the laser beam to be detected and the laser beam with an actual exit angle of 0 degrees. The detailed description of how the control module determines the actual exit angle of the laser beam based on the target position can be referred to in the related content of Figure 6 .

[0065] Figure 3 is a schematic diagram of an exemplary light sensing device according to some embodiments of the present specification.

[0066] In some embodiments, refer to Figure 3As shown, the light sensing device 120 can include an incident light end 123, an emergent light end 124, and a light sensing part 122. The incident light end 123 is configured to receive at least part of the light signal of the first light spot 126, the emergent light end 124 is configured to output the light signal and generate a second light spot 127, and the light sensing part 122 is configured to sense the second light spot 127 to obtain a first position of the second light spot 127 in the light sensing device 120. In some embodiments, the light sensing device 120 can further include an optical fiber 125, one end of the optical fiber 125 being connected to the incident light end 123 and the other end being connected to the emergent light end 124, for transmitting the light signal received by the incident light end 123 to the emergent light end 124.

[0067] The incident light end 123 can be an end face allowing the light signal to enter. In some embodiments, a plurality of incident ports 1231 can be formed on the incident light end 123, each incident port 1231 being arranged at intervals along the first direction, and the light signal of the first light spot 126 can enter the light sensing device 120 from the incident port 1231. In some embodiments, the distance between adjacent incident ports 1231 can be set to be between 0.5 mm and 2 mm. In some embodiments, the diameter of the incident port 1231 and the distance between adjacent incident ports 1231 can be set to be micron-level dimensions to improve the accuracy of collecting the first light spot 126. For example, the distance between adjacent incident ports 1231 can be set to be between 100 microns and 200 microns. For another example, the diameter of the incident port 1231 can be set to be between 50 microns and 200 microns. In some embodiments, each incident port 1231 can be provided with an optical fiber 125, and the light signal of the first light spot 126 enters the incident port 1231 and is directly conducted via the optical fiber 125.

[0068] In some embodiments, the length of the incident light end 123 can be determined according to the measurement range of the laser radar 110 to be calibrated. In some embodiments, the length of the incident light end 123 in the first direction can be set to be within a range of 1 meter to 2 meters. In some embodiments, the incident light end 123 can cover the measurement space 130 in the first direction, i.e., the incident light end 123 completely covers the projection range along the first direction on the projection plane in the measurement space 130. For example, the scanning range of the laser radar 110 to be calibrated in the first direction is -45 degrees to 45 degrees, and the distance between the laser radar 110 to be calibrated and the projection plane is 1 meter, then the length of the incident light end 123 can be set to be 2 meters to cover the measurement space 130 in the first direction.

[0069] In some embodiments, at least a portion of the first light spot 126 can be formed on the incident light end 123, and the incident light end 123 can receive at least a portion of the light signal of the first light spot 126. In some embodiments, the area of the first light spot 126 is smaller than the area of the incident port 1231, and one incident port 1231 of the incident light end 123 can receive the first light spot 126. In some embodiments, the area of the first light spot 126 is larger than the area of the incident port 1231, and after the to-be-calibrated laser radar 110 emits a laser beam towards the measurement space 130, the photosensitive device 120 receives the laser beam in the measurement space 130 by moving acquisition and forms the first light spot 126 on the incident light end 123. In some embodiments, the light rays of the first light spot 126 can be emitted from the incident light end 123 and transmitted to the exit light end 124 through the optical fiber 125 to form the second light spot 127 on the photosensitive part 122. For more information about the incident light end 123 receiving the first light spot 126, please refer to the related description of the present specification, which will not be repeated here. Figure 4A

[0070] The exit light end 124 can be used to output a light signal. In some embodiments, the exit light end 124 is provided with a plurality of exit ports 1241, and the number of exit ports 1241 is consistent with the number of incident ports 1231. Each exit port 1241 and each incident port 1231 are connected by an optical fiber 125, so that the incident port 1231 and the exit port 1241 are one-to-one corresponding. When the incident port 1231 acquires the first light spot 126, the optical fiber 125 can transmit the light signal to the corresponding exit port 1241, and the corresponding exit port 1241 projects the light signal to the photosensitive part 122 to form the second light spot 127.

[0071] In some embodiments, the length of the exit light end 124 in the first direction is smaller than the length of the incident light end 123 in the first direction. In some embodiments, the length of the exit light end 124 in the first direction ranges from 2 centimeters to 4 centimeters. In some embodiments, the distance between the exit ports 1241 on the exit light end 124 can be between 1 micrometer and 10 micrometers. Through this setting, the resolution of the exit light end 124 projecting the second light spot 127 on the photosensitive part 122 can reach 1 micrometer to 10 micrometers, with very high measurement accuracy.

[0072] ​The second light spot 127 is the light spot after the light sensing device 120 projects at least a portion of the first light spot 126 into the interior thereof. In some embodiments, after the incident light end 123 of the light sensing device 120 acquires the first light spot 126, it is transferred to the output light end 124 through the scaling of the optical fiber 125, and the second light spot 127 is projected from the output light end 124. The shape and size of the second light spot 127 are related to the size of the output light end 124. In some embodiments, the second light spot 127 projected by the output light end 124 can be formed on the photosensitive portion 122. For more information about the formation of the second light spot 127 on the photosensitive portion 122, please refer to this specification. Figure 4B The relevant description will not be repeated here.

[0073] The photosensitive portion 122 may refer to a device that can sense the light signal of the light spot projected by the laser beam onto its surface and convert the light signal into the required analog signal. In some embodiments, the photosensitive portion 122 includes but is not limited to a photoelectric position sensor (PSD), a charge coupled device (CCD), a complementary metal oxide semiconductor (CMOS), etc. In some embodiments, the shape of the photosensitive portion 122 may be the same as that of the light emitting end 124, so that the second light spot 127 projected by the light emitting end 124 can be formed within the range of the photosensitive portion 122. In some embodiments, the shape of the photosensitive portion 122 may also be different from that of the light emitting end 124. In some embodiments, the size of the photosensitive portion 122 may be slightly larger than that of the light emitting end 124 so as to fully acquire the signal of the second light spot 127.

[0074] In some embodiments, the photosensitive portion 122 is a PSD sensor, which can convert the position of a light spot on a photosensitive surface into an electrical signal. The conditioning circuit of the PSD sensor can convert the electrical signal into an analog signal or a digital signal. The analog signal or digital signal may include position information of the second light spot 127 on the sensing surface. Based on the position information, the coordinate position of the corresponding first light spot 126 in the preset coordinate system can be determined.

[0075] Figure 4A is a schematic diagram of a first light spot 126 obtained by the light sensing device 120 according to some embodiments of this specification.

[0076] In some embodiments, see Figure 4AAs shown, the first light spot 126 can be a circular light spot. In some embodiments, if the size of the first light spot 126 is larger than the size of the incident port 1231 of the incident light end 123, the first light spot 126 covers multiple incident ports 1231 of the incident light end 123 in the first direction.

[0077] In some embodiments, when the light sensing device 120 moves along the guide rail 180 and passes through the first light spot 126 , the number of incident ports 1231 covered by the first light spot 126 may vary.

[0078] Figure 4B is a schematic diagram of a second light spot 127 obtained by the light sensing device 120 according to some embodiments of this specification.

[0079] In some embodiments, see Figure 4B After the light sensing device 120 acquires the first light spot 126, it transmits the light to the light sensing unit 122 via the light emitting end 124 to obtain the second light spot 127. In some embodiments, the second light spot 127 is in the shape of an elongated strip along the first direction, and the length of the elongated strip is related to the number of incident ports 1231 covered by the first light spot 126. In some embodiments, the position coordinates of the second light spot 127 in the one-dimensional coordinate system can be the coordinates of the midpoint of the second light spot 127 in the first direction.

[0080] In some embodiments, when the photosensitive device 120 moves past the first light spot 126, although the number of incident ports 1231 covered by the first light spot 126 is different, the y-coordinate of the midline of the first light spot 126 parallel to the x-axis remains unchanged. Therefore, the coordinate of the midpoint of the second light spot 127 projected onto the photosensitive portion 122 in the one-dimensional coordinate system also remains unchanged.

[0081] In some embodiments, the control module can obtain a first position of the second light spot 127 in the light sensing device 120, and determine the first coordinate based on the first position. In some embodiments, the coordinate system on the light sensing portion 122 can be a one-dimensional coordinate system, and the coordinate axis of the one-dimensional coordinate system can be parallel to the Y-axis in the preset coordinate system. In some embodiments, the coordinate axis of the one-dimensional coordinate system has a mapping relationship with the Y-axis in the preset coordinate system. In some embodiments, the projection position of the exit port 1241 corresponding to the entrance port 1231 with a Y-axis coordinate value of 0 on the incident light end 123 in the preset coordinate system on the light sensing portion can be the origin of the coordinate axis of the one-dimensional coordinate system. In some embodiments, the unit length of the coordinate axis of the one-dimensional coordinate system has a preset proportional relationship with the unit length of the Y-axis in the preset coordinate system. In some embodiments, the proportional relationship can be determined based on the distribution of the entrance ports 1231 of the incident light end 123 and the distribution of the exit ports 1241 of the exit light end 124. In some embodiments, the proportional relationship can be equal to the ratio of the distribution interval of the exit ports 1241 to the distribution interval of the entrance ports 1231. For example, if the ratio of the distribution interval of the exit ports 1241 to the distribution interval of the entrance ports 1231 is 1:5, then the proportional relationship between the unit length of the coordinate axis of the one-dimensional coordinate system and the unit length of the Y-axis in the preset coordinate system is also 1:5, and at this time, the coordinate value of the coordinate point in the one-dimensional coordinate system is 2, and the coordinate value of the Y-axis in the preset coordinate system is 10. In some embodiments, the coordinate position of the first light spot 126 in the Y-axis direction can be determined by determining the position coordinate of the second light spot 127 in the one-dimensional coordinate system, and the coordinate position of the first light spot 126 in the Y-axis direction is the first position. Since the distribution interval of the exit ports of the light sensing device can be set to be between 1 micrometer and 10 micrometers, the first position obtained by this method has extremely high precision, and thus the calibration accuracy of the laser radar can be greatly improved.

[0082] In some embodiments, if the size of the first light spot 126 completely falls within the size range of one entrance port 1231 of the incident light end 123, that is, one entrance port 1231 can completely receive the light signal of the first light spot 126, at this time, the control module can determine the first position of the first light spot 126 according to the projection position of the exit port 1241 corresponding to the entrance port 1231 in the one-dimensional coordinate system, and the mapping relationship between the one-dimensional coordinate system and the preset coordinate system.

[0083] The light sensing device 120 moves to scan the first light spot 126 in the first direction. Since the number of the entrance ports 1231 covered by the first light spot 126 can be different, the light signal intensity of the first light spot 126 obtained by the incident light end 123 can also be different, where the light signal intensity is the energy of the light received by the incident light end 123. The more the number of the entrance ports 1231 covered by the incident light end 123, the more the optical fibers 125 receiving the light signal, and the stronger the light signal intensity of the second light spot 127 generated by the corresponding exit light end 124. For example, the light signal intensity obtained by the incident light end 123 at the middle position of the first light spot 126 is greater than the light signal intensity obtained by the incident light end 123 at the two sides of the first light spot 126. In some embodiments, the stronger the light signal intensity of the second light spot 127, the stronger the light signal intensity of the second light spot 127 obtained by the light sensing part 122, and the stronger the electrical signal generated thereby. For example, the more the optical fibers 125 outputting the light signal, the greater the light signal intensity received by the light sensing part 122, and the greater the electrical signal generated thereby. In some embodiments, according to the change of the light signal or electrical signal intensity, the control module can determine the center point of the first light spot 126 in the second direction, which can be the position with the strongest light signal intensity in the process of the light sensing device 120 scanning the first light spot 126. In some embodiments, the control module can determine the position coordinates of the light sensing device 120 in the second direction according to the center point, and the position coordinates are the second position of the control module on the guide rail.

[0084] Figure 5 is a flowchart of a laser radar calibration method according to some embodiments of the present specification.

[0085] In some embodiments, the laser radar calibration method can include flow 500. In some embodiments, the flow 500 can be performed by the control module, including the following steps:

[0086] Step 510, obtaining, by the light sensing device, a first light spot of a laser beam emitted by the laser radar to be calibrated in the measurement space.

[0087] In some embodiments, the control module can control the laser radar to be calibrated 110 to emit a laser beam towards the instructed exit angle. The instructed exit angle refers to the exit angle of the control module instructing the laser radar to be calibrated 110. For example, the control module can instruct the exit angle of the laser beam of the laser radar to be calibrated 110 in the horizontal direction to be +45 degrees, and the exit angle in the vertical direction to be +10 degrees. In some embodiments, the instructed exit angle can be used as a reference benchmark for calibrating the laser radar to be calibrated 110.

[0088] In some embodiments, the light sensing device 120 covers the measurement space 130 along a first direction. In some embodiments, the light sensing device 120 can move along a second direction in the measurement space 130 to obtain the first light spot 126 of the laser beam in the measurement space 130, the second direction being perpendicular to the first direction. In some embodiments, when the light sensing device 120 moves through the laser beam of the to-be-calibrated laser radar 110, the laser beam can form the first light spot 126 on the light sensing device 120, and the incident light end 123 of the light sensing device 120 can obtain the light information of the first light spot 126. The specific process of the light sensing device 120 obtaining the first light spot 126 can be referred to the description of Figure 4A , which will not be repeated here.

[0089] In step 520, a second light spot is generated in the light sensing device based on the first light spot, the size of the second light spot being smaller than the size of the first light spot.

[0090] After the incident light end 123 of the light sensing device 120 obtains the first light spot 126, the first light spot 126 is conducted through the optical fiber 125 and output from the exit light end 124, and a second light spot 127 is generated in the light sensing part 122, and the light sensing part 122 can obtain the light signal of the second light spot 127, the light signal including the light signal intensity and the position of the second light spot 127. The specific details of the light sensing device 120 generating the second light spot 127 can be referred to the related description of Figure 4A-4B , which will not be repeated here.

[0091] In step 530, a target position of the first light spot in a preset coordinate system is determined based on the second light spot.

[0092] In some embodiments, the preset coordinate system can include a space center origin O, X-axis, Y-axis and Z-axis perpendicular to each other, wherein the X-axis can be along the first direction, the Y-axis can be along the second direction, and the Z-axis can be along the third direction.

[0093] In some embodiments, the control module can obtain a first position of the second light spot 127 in the light sensing device 120, and determine a first coordinate based on the first position. In some embodiments, the first coordinate can be a coordinate value corresponding to the Y-axis. In some embodiments, the first position can be the position information of the second light spot 127 in the light sensing device 120. The specific method of determining the first coordinate through the first position can be referred to the related description of Figure 1 and Figure 4A , which will not be repeated here.

[0094] In some embodiments, the control module can obtain a first position of the second light spot in the light sensing device 120. In some embodiments, the incident light end 123 can receive at least part of the light signal of the first light spot 126, the emergent light end 124 can output the light signal obtained by the incident light end 123, and generate the second light spot 127 in the light sensing part 122. The light sensing part 122 can sense the second light spot 127 and obtain the first position of the second light spot 127 in the light sensing device 120. In some embodiments, the specific content of the control module determining the first position through the light sensing device 120 can be referred to in the related description of Figure 1 and Figure 4A- Figure 4B , which will not be repeated here.

[0095] In some embodiments, the control module can obtain a second position of the light sensing device 120 corresponding to the second light spot 127 in the second direction, and determine a second coordinate based on the second position. In some embodiments, the second position can correspond to a position on the guide rail 180. In some embodiments, the second coordinate can be a coordinate value of the X-axis. In some embodiments, the specific method of the control module determining the second coordinate can be referred to in the related description of Figure 1 and Figure 4B , which will not be repeated here.

[0096] In some embodiments, the control module can determine a target position of the first light spot 126 in a preset coordinate system based on the first coordinate and the second coordinate.

[0097] In step 540, the actual emergent angle of the laser beam is determined based on the target position.

[0098] In some embodiments, the control module can determine the actual emergent angle of the laser beam according to the positional relationship between the target position and the spatial center origin O of the laser radar to be calibrated. The spatial center origin O is the mapping position of the laser beam on the receiving screen when the actual emergent angle of the laser beam is 0 degrees. In some embodiments, through the first coordinate and the second coordinate in the target position and the spatial position relationship of the laser radar to be calibrated, through the arctangent function, the control module can obtain the actual emergent angle of the laser beam in the vertical direction based on the first coordinate, and the control module can obtain the actual emergent angle of the laser beam in the horizontal direction based on the second coordinate. The specific calculation method of determining the actual emergent angle of the laser beam can be referred to in the related description of Figure 6 .

[0099] Figure 6 is a schematic diagram of an exemplary laser radar calibration method according to some embodiments of the present specification.

[0100] For the convenience of understanding, the laser radar calibration process will be described in specific embodiments in combination with Figure 6 .

[0101] In some embodiments, in the preset coordinate system, the spatial center origin O is the mapped position on the measurement space 130 when the actual exit angle of the laser beam is 0 degree. The specific determination method of the spatial center origin O can be referred to the related description of Figure 2 In some embodiments, the XOY plane of the preset coordinate system can be arranged in the projection plane, and the Z axis of the preset coordinate system is perpendicular to the XOY plane. In some embodiments, the coordinate position of the first light spot 126 in the XOY plane of the preset coordinate system is the target position A, and the position of the to-be-calibrated laser radar 110 in the spatial coordinate system is B. In some embodiments, the first edge length can be determined based on the position information of the target position A and the spatial center origin O in the preset coordinate system. The target position A can be the actual position of the first light spot 126. In some embodiments, the first edge length can be the distance y1 of the first light spot 126 and the spatial center origin O in the first direction. In some embodiments, the first edge length can also be the distance x1 of the first light spot 126 and the spatial center origin O in the second direction. For example, the target position A of the first light spot 126 is (0.5, 0.7), and Figure 6 The values corresponding to x1 and y1 in (a) are 0.5 and 0.7 respectively. The value corresponding to x1 is the distance of point A and point O in the second direction, and the value corresponding to y1 is the distance of point A and point O in the first direction. The unit of the distance can be meters, for example.

[0102] In some embodiments, the second edge length is determined based on the distance from the laser outlet of the to-be-calibrated laser radar 110 to the preset coordinate plane. The preset coordinate plane refers to the plane in the preset coordinate system that coincides with the projection plane, such as the XOY plane. In some embodiments, the distance from the laser outlet of the to-be-calibrated laser radar 110 to the preset coordinate plane is equal to the second edge length. For example, the distance from the laser outlet of the to-be-calibrated laser radar 110 to the preset coordinate plane is l (the unit of the distance can be meters, for example), and the second edge length is 1.

[0103] In some embodiments, the actual exit angle of the laser beam is determined by processing the first edge length and the second edge length using the arctangent function. In some embodiments, since the second edge length is perpendicular to the first edge length, based on the second edge length and the first edge length, the actual exit angle of the laser beam in the three-dimensional space can be obtained by arctangent calculation. In some embodiments, based on the specified exit angle of the laser beam in the three-dimensional space, the error angle between the actual exit angle and the specified exit angle can be calculated, and the to-be-calibrated laser radar 110 can be adjusted according to the error angle.

[0104] In some embodiments, the actual exit angle of the to-be-calibrated laser radar 110 can also be represented by the horizontal exit angle and the vertical exit angle. In some embodiments, as Figure 6(b) and (c) shown, based on the value corresponding to x1 and the second side length l, the actual exit angle a of the laser beam in the horizontal direction can be obtained by the inverse tangent calculation, that is, the actual azimuth angle of the laser beam; based on the value corresponding to y1 and the second side length l, the actual exit angle β of the laser beam in the vertical direction can be obtained by the inverse tangent calculation, that is, the actual pitch angle of the laser beam. In some embodiments, the error angle of the laser beam in the horizontal direction and the vertical direction can be obtained by calculating the difference between the specified exit angle of the laser beam in the horizontal direction and the vertical direction of the to-be-calibrated laser radar 110 and a and β respectively.

[0105] In some embodiments, the laser beam emitted by the to-be-calibrated laser radar 110 can be adjusted based on the error angle of the laser beam. In some embodiments, by calibrating laser beams of different specified exit angles, an error angle table or curve (reflecting the mapping relationship between different specified exit angles and actual exit angles) of the to-be-calibrated laser radar 110 can be obtained to adjust the laser beam emitted by the to-be-calibrated laser radar 110.

[0106] It should be noted that the above description of the method 600 is only for example and illustration, and does not limit the scope of the present specification. Those skilled in the art can make various modifications and changes to the method 600 under the guidance of the present specification. For example, Figure 6 The preset coordinate system in the above description can be established with the vertex of the base 160 of the laser radar calibration device 100 as the spatial center origin O, and the side of the base 160 as the X and Y axes. However, these modifications and changes are still within the scope of the present specification.

[0107] The beneficial effects that the embodiments of the present specification can bring include but are not limited to: (1) using a photosensitive device to replace a camera to obtain a light spot, which can obtain a clear light signal, so as to accurately determine the position and size of the light spot, thereby improving the precision and accuracy of laser radar calibration; (2) the photosensitive device can be a PSD sensor, which has a wide spectral response and can cover most of the wave bands of the laser beam, can improve the light signal collection intensity, and has high resolution, further improving the precision and accuracy of laser radar calibration; (3) the photosensitive device includes a light sensing part, an optical fiber, an incident light end and an exit light end, and the size of the second light spot collected by the exit light end is smaller than the size of the first light spot of the incident light end, so that the incident light end can cover the field of view of the laser radar through the optical fiber under the condition that the size of the light sensing part is small, and the photosensitive device can collect complete and clear light spots. It should be noted that different embodiments can have different beneficial effects, and in different embodiments, the beneficial effects that can be produced can be any one or a combination of the above, or any other beneficial effects that can be obtained.

[0108] Having described the basic concepts, it is obvious to those skilled in the art that the foregoing detailed description is merely illustrative and not restrictive of the present specification. Various modifications, improvements, and changes can be made to the present specification by those skilled in the art, although not explicitly described herein. Such modifications, improvements, and changes are suggested by the present specification, and thus still fall within the spirit and scope of the exemplary embodiments of the present specification.

[0109] Meanwhile, specific words are used in the present specification to describe the embodiments of the present specification. As "one embodiment", "an embodiment", and / or "some embodiments" mean a certain feature, structure, or characteristic in connection with at least one embodiment of the present specification. Therefore, it should be emphasized and noted that "an embodiment" or "one embodiment" or "an alternative embodiment" mentioned in different places in the present specification does not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the present specification can be properly combined.

[0110] In addition, those skilled in the art can understand that aspects of the present specification can be described and claimed in a broad form or in a variety of specific forms, including any new and useful processes, machines, products, or compositions of matter, or any new and useful improvements thereof. Accordingly, various aspects of the present specification can be performed entirely by hardware, entirely by software (including firmware, resident software, microcode, etc.), or by a combination of hardware and software. The above hardware or software can be referred to as "data blocks", "modules", "engines", "units", "components", or "systems". In addition, aspects of the present specification can be embodied as a computer product located in one or more computer readable media, including computer readable program code.

[0111] The computer storage media can include a propagated data signal with computer program code embodied therein, e.g., in baseband or as part of a carrier wave. Such propagated signal can take a variety of forms, including but not limited to electro-magnetic, optical, or any suitable combination thereof. Computer storage media can be any computer readable medium except for a propagating transitory, signal per se. The computer storage media can be any computer readable medium that can be accessed by a general purpose or special purpose computing system, apparatus, or device to implement the techniques for which that computer storage media contains or stores program code. Program code embodied on a computer storage medium can be transmitted using any appropriate medium, including but not limited to wireless, wire line, optical fiber cable, RF, or any suitable combination of the foregoing.

[0112] Computer program code for carrying out operations of the aspects of the present specification can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET, Python, and conventional procedural programming languages, such as the "C" programming language, Visual Basic, Fortran 2003, Perl, COBOL 2002, PHP, ABAP, dynamic programming languages, such as Python, Ruby and Groovy, or other programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider). In some embodiments, electronic program code can be downloaded from an on-demand computing platform, such as Amazon Web Services, Microsoft Azure, or Google Cloud Platform, or a service provider, such as Salesforce.com. In some embodiments, electronic program code can be downloaded from a cloud computing environment, or used as a service, such as Software as a Service (SaaS).

[0113] In addition, the order of execution or sequence of any of the processes depicted in or comprising the embodiments of the disclosure, and the use or involvement of numbers, letters, or other designations there with is not intended to and should not be construed to in any

[0114] Accordingly, it is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments of the disclosure will be apparent to those of skill in the art upon reviewing the above description, and it is therefore contemplated that future devices, systems, and methods will be derived from the disclosure without departing from the scope of the disclosure, the object of which being to provide improved systems and methods for providing a user with a personalized experience.

[0115] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0116] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflicting with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent or conflicting with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0117] Finally, it should be understood that the embodiments described in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A laser radar calibration device, comprising: A light sensing device, used to obtain a first light spot of a laser beam emitted by the laser radar to be calibrated in the measurement space, the light sensing device comprising: An incident light end, configured to receive at least a portion of the optical signal of the first light spot; an optical output end, configured to output the optical signal and generate a second light spot; the size of the second light spot is smaller than that of the first light spot; a light-sensing portion, configured to sense the second light spot to obtain a first position of the second light spot in the light-sensing device; and A control module is configured to determine a target position of the first light spot in a preset coordinate system based on the second light spot, and to determine an actual emission angle of the laser beam based at least on the target position.

2. According to the device according to claim 1, the photosensitive device covers the measuring space along a first direction; the device also includes a guide rail arranged in the measuring space, and the photosensitive device is installed on the guide rail; the photosensitive device can move along the guide rail in a second direction of the measuring space; the second direction is perpendicular to the first direction.

3. The device according to claim 2, wherein, in order to determine the target position of the second light spot in a preset coordinate system, the control module is further configured to: Acquire a first position of the second light spot in the light sensing device, and determine a first coordinate based on the first position, where a coordinate axis of the first coordinate is parallel to the first direction; Acquire a second position of the light sensing device on the guide rail corresponding to the second light spot, and determine a second coordinate based on the second position, where a coordinate axis of the second coordinate is parallel to the second direction; A target position of the first light spot in a preset coordinate system is determined based on the first coordinate and the second coordinate.

4. The device according to claim 3 further includes a fixture for carrying the laser radar to be calibrated, and the fixture is configured to be movable along a third direction relative to the measurement space, and the third direction is perpendicular to the first direction and the second direction.

5. A laser radar calibration method, the method comprising: Acquire a first light spot of the laser beam emitted by the laser radar to be calibrated in the measurement space through a light sensing device; The light sensing device includes a light incident end, a light emitting end and a light sensing part; receiving at least a portion of the optical signal of the first light spot through the incident light end; Outputting the optical signal through the light output end and generating a second light spot; wherein the size of the second light spot is smaller than the size of the first light spot; sensing the second light spot by the light sensing portion to obtain a first position of the second light spot in the light sensing device; determining a target position of the first light spot in a preset coordinate system based on the second light spot; as well as, An actual emission angle of the laser beam is determined based on the target position.

6. The method according to claim 5, wherein acquiring the first light spot of the laser beam in the measurement space by a light sensing device comprises: Moving the light sensing device along a second direction in the measurement space to obtain a first light spot of the laser beam in the measurement space; The light sensing device covers the measurement space along a first direction; and the second direction is perpendicular to the first direction.

7. The method according to claim 6, wherein determining the target position of the first light spot in a preset coordinate system based on the second light spot comprises: Acquire a first position of the second light spot in the light sensing device, and determine a first coordinate based on the first position, where a coordinate axis of the first coordinate is parallel to the first direction; Acquire a second position of the light-sensing device corresponding to the second light spot in the second direction, and determine a second coordinate based on the second position, where a coordinate axis of the second coordinate is parallel to the second direction; A target position of the first light spot in the preset coordinate system is determined based on the first coordinate and the second coordinate.

Images