Intrinsic parameter correction method for semi-solid-state lidar based on planar constraints

Abstract

This invention discloses an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints, comprising the following steps: establishing a calibration environment including a semi-solid-state lidar and a planar calibration board; scanning the scanning points of the planar calibration board using the semi-solid-state lidar, recording the signal flight time and mirror rotation angle corresponding to each scanning point; inputting the signal flight time, mirror rotation angle, and intrinsic parameters of the semi-solid-state lidar into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration board; adjusting the position of the planar calibration board to obtain multiple sets of three-dimensional point cloud data of the planar calibration board; calculating the planar constraint error of each set based on the multiple sets of three-dimensional point cloud data; calculating the global constraint error based on the planar constraint error; adjusting the lidar intrinsic parameters within the error range to obtain the corrected intrinsic parameters of the semi-solid-state lidar. This application can improve the intrinsic parameter accuracy of the semi-solid-state lidar, thereby improving the accuracy of lidar three-dimensional perception.

Description

Technical Field

[0001] This invention relates to the field of radar intrinsic parameter correction technology, and in particular to an intrinsic parameter correction method for semi-solid-state lidar based on planar constraints. Background Technology

[0002] Currently, LiDAR, as an advanced three-dimensional perception sensor, is a popular research area in fields such as intelligent assisted driving, drones, smart cities, and remote sensing technology. Compared with traditional two-dimensional image cameras and ultrasonic radar, LiDAR has advantages such as wide detection range, high accuracy, rich feedback information, and strong anti-interference capability. Based on the scanning method, LiDAR can be classified into mechanical, semi-solid-state (MEMS, rotating mirror type), and pure solid-state (OPA, Flash) types. Among them, the optical part of the rotating mirror semi-solid-state LiDAR consists of prisms, motors, and transmitters. This structure gives it better heat resistance and durability compared to other types, and makes it easier to pass various standard tests, thus it is widely used in fields such as autonomous driving, AGV robots, and rail transit inspection.

[0003] A rotating mirror-type semi-solid-state lidar continuously changes the emission direction of a pulsed laser by rotating a mirror, achieving orderly scanning in the target direction. The pulsed beam is reflected by an object in the target direction and then received by the lidar's built-in photoelectric signal converter, completing a measurement process. The data obtained from this signal transmission and reception process only reflects the one-dimensional distance relationship between the lidar and the target object; a complete three-dimensional relative positional relationship is required by combining the lidar's internal optical path structural parameters. Therefore, the accuracy of the intrinsic parameters has a significant impact on the accuracy of the lidar's three-dimensional perception. However, in the actual production and assembly of lidars, structural intrinsic parameters such as the shape of the rotating mirror and the position and emission direction of the laser emitter often deviate from the design values ​​due to various factors. This greatly limits the lidar's high-precision perception and measurement in three-dimensional space. Summary of the Invention

[0004] The purpose of this invention is to overcome the above-mentioned technical deficiencies and propose an intrinsic parameter correction method for semi-solid-state lidar based on planar constraints, which can effectively improve the intrinsic parameter accuracy of semi-solid-state lidar, thereby improving the accuracy of lidar three-dimensional perception.

[0005] To achieve the above-mentioned technical objectives, in a first aspect, the present invention provides an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints, comprising the following steps:

[0006] A calibration environment including a semi-solid-state lidar and a planar calibration board is set up. The semi-solid-state lidar is used to scan the scanning points of the planar calibration board, and the signal flight time and mirror rotation angle corresponding to each scanning point are recorded.

[0007] The signal flight time, the rotation angle of the rotating mirror, and the intrinsic parameters of the semi-solid-state lidar are input into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration plate.

[0008] The position of the planar calibration plate is adjusted, and the semi-solid-state lidar is used to scan the scanning points of the planar calibration plate after the position is adjusted, so as to obtain multiple sets of the three-dimensional point cloud data of the planar calibration plate;

[0009] The planar constraint error for each group is calculated based on the multiple groups of 3D point cloud data.

[0010] The global constraint error is calculated based on the planar constraint error. The intrinsic parameters of the semi-solid-state lidar are adjusted within the range of the global constraint error, and the global planar constraint error is optimized to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

[0011] Compared with existing technologies, the beneficial effects of the intrinsic parameter correction method for semi-solid-state lidar based on planar constraints provided by this invention include:

[0012] The intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints of the present invention only requires a planar constraint plate to correct the internal structural parameter errors of the lidar. By repeatedly adjusting the position of the planar calibration plate, the semi-solid-state lidar is used to scan the scanning points of the planar calibration plate after the adjustment to obtain multiple sets of three-dimensional point cloud data of the planar calibration plate. Then, the planar constraint error of each set is calculated based on the three-dimensional point cloud data, and then the global constraint error is calculated. Within the range of the global constraint error, the intrinsic parameters of the semi-solid-state lidar are adjusted, and the global planar constraint error is optimized to obtain the corrected intrinsic parameters of the semi-solid-state lidar, thereby improving the measurement accuracy of the semi-solid-state lidar in three-dimensional space. This is of great significance for the development of high-precision semi-solid-state lidar.

[0013] According to some embodiments of the present invention, the intrinsic parameters of the semi-solid-state lidar include: ρ, θ (rad): jointly representing the direction of the incident laser; X L ,Y L Z L : The three-dimensional coordinates of the laser emitter; β (rad): representing the mirror tilt angle; d: representing the distance from the mirror to the origin, characterized in that the calculation of the three-dimensional point cloud data of the planar calibration plate includes the following steps:

[0014] The reflection direction vector is calculated based on the rotation angle of the rotating mirror and the intrinsic parameters. The reflection direction vector is used to represent the direction vector of the laser after it is reflected by the mirror.

[0015] The distance information from the emitter to the mirror and the coordinate information of the laser reflection point on the mirror are calculated based on the rotation angle of the rotating mirror and the intrinsic parameters. The distance information is used to represent the distance from the emitter to the mirror surface of the rotating mirror, and the coordinate information is used to represent the coordinates of the laser reflection point after it is reflected from the mirror surface.

[0016] The three-dimensional point cloud data of the planar calibration plate is calculated based on the signal flight time, the reflection direction vector, the distance information, and the coordinate information.

[0017] According to some embodiments of the present invention, the three-dimensional point cloud data of the planar calibration plate is calculated based on the signal flight time, the reflection direction vector, the distance information, and the coordinate information, and the analytical expression is as follows:

[0018]

[0019] Wherein, λ is the distance information, that is, the distance from the laser emitter to the mirror surface; The coordinate information refers to the coordinates of the laser at the point of reflection on the mirror surface; Let C be the reflection direction vector; C be the speed of light; and t be the signal flight time.

[0020] According to some embodiments of the present invention, the planar constraint error of each set is calculated based on multiple sets of the three-dimensional point cloud data, and the analytical expression is as follows:

[0021]

[0022] According to some embodiments of the present invention, the global constraint error is calculated based on the planar constraint error, including the following steps:

[0023] The global constraint error is obtained by summing the plane constraint errors of each group.

[0024] According to some embodiments of the present invention, the modified intrinsic parameters of the semi-solid-state lidar are expressed analytically as follows:

[0025] ρ,θ,X L ,Y L Z L ,β,d=argminError

[0026] Where Error is the global constraint error, and the intrinsic parameters of the semi-solid-state lidar include: ρ, θ (rad): together representing the direction of the incident laser; X L ,Y L Z L : Represents the position coordinates of the laser emitter; β (rad): Represents the mirror tilt angle; d: Represents the distance from the mirror to the origin.

[0027] Secondly, the technical solution of the present invention provides an intrinsic parameter correction system for a semi-solid-state lidar based on planar constraints, comprising:

[0028] The data recording module is used to record the signal flight time and the rotation angle of the rotating mirror corresponding to each scanning point of the semi-solid-state lidar scanning the planar calibration plate;

[0029] The three-dimensional point cloud data calculation module is used to input the signal flight time, the rotation angle of the rotating mirror and the intrinsic parameters of the semi-solid-state lidar into the lidar ranging model, calculate the three-dimensional point cloud data of the planar calibration plate, adjust the position of the planar calibration plate, and use the semi-solid-state lidar to scan the scanning points of the adjusted planar calibration plate to obtain multiple sets of the three-dimensional point cloud data of the planar calibration plate.

[0030] The planar constraint error calculation module is used to calculate the planar constraint error of each group based on multiple groups of the three-dimensional point cloud data.

[0031] The intrinsic parameter correction module is used to calculate the global constraint error based on the planar constraint error, adjust the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error, and optimize the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

[0032] Thirdly, the present invention provides a computer-readable storage medium storing computer-executable instructions for causing a computer to execute the intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints as described in any one of the first aspects.

[0033] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0034] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein the abstract drawings are to be completely consistent with one of the drawings in the specification:

[0035] Figure 1 A flowchart illustrating an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints, provided as an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of the calibration environment for an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints provided in an embodiment of the present invention;

[0037] Figure 3A schematic diagram of the flight time and rotation angle of an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints provided in an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of some lidar intrinsic parameters provided by an embodiment of the present invention for a semi-solid-state lidar intrinsic parameter correction method based on planar constraints. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0040] It should be noted that although functional modules are divided in the system diagram and the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than the module division in the system or the order in the flowchart. The terms "first," "second," etc., in the specification, claims, and the aforementioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0041] The embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0042] Reference Figures 1 to 4 , Figure 1 A flowchart illustrating an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints, provided as an embodiment of the present invention; Figure 2 A schematic diagram of the calibration environment for an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints provided in an embodiment of the present invention; Figure 3 A schematic diagram of the flight time and rotation angle of an intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints provided in an embodiment of the present invention. Figure 4 This is a schematic diagram of some lidar intrinsic parameters provided by an embodiment of the present invention for a semi-solid-state lidar intrinsic parameter correction method based on planar constraints.

[0043] The intrinsic parameter correction method for semi-solid-state lidar based on planar constraints includes, but is not limited to, steps S110 to S150.

[0044] Step S110: Set up a calibration environment including a semi-solid-state lidar and a planar calibration board. Use the semi-solid-state lidar to scan the scanning points of the planar calibration board and record the signal flight time and mirror rotation angle corresponding to each scanning point.

[0045] Step S120: Input the signal flight time, the rotating mirror rotation angle, and the intrinsic parameters of the semi-solid-state lidar into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration plate.

[0046] Step S130: Adjust the position of the planar calibration plate and use a semi-solid-state LiDAR to scan the scanning points of the adjusted planar calibration plate to obtain multiple sets of three-dimensional point cloud data of the planar calibration plate.

[0047] Step S140: Calculate the planar constraint error for each set of three-dimensional point cloud data.

[0048] Step S150: Calculate the global constraint error based on the planar constraint error, adjust the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error, and optimize the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

[0049] In one embodiment, the intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints includes the following steps: establishing a calibration environment including a semi-solid-state lidar and a planar calibration board; using the semi-solid-state lidar to scan the scanning points of the planar calibration board and recording the signal flight time and mirror rotation angle corresponding to each scanning point; inputting the signal flight time, mirror rotation angle, and intrinsic parameters of the semi-solid-state lidar into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration board; adjusting the position of the planar calibration board and using the semi-solid-state lidar to scan the scanning points of the adjusted planar calibration board to obtain multiple sets of three-dimensional point cloud data of the planar calibration board; calculating the planar constraint error of each set based on the multiple sets of three-dimensional point cloud data; calculating the global constraint error based on the planar constraint error; adjusting the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error and optimizing the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

[0050] The intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints in this embodiment only requires a planar constraint plate to correct the internal structural parameter errors of the lidar. By repeatedly adjusting the position of the planar calibration plate, the semi-solid-state lidar scans the scanning points of the adjusted planar calibration plate to obtain multiple sets of three-dimensional point cloud data of the planar calibration plate. Then, the planar constraint error of each set is calculated based on the three-dimensional point cloud data, and then the global constraint error is calculated. Within the range of the global constraint error, the intrinsic parameters of the semi-solid-state lidar are adjusted, and the global planar constraint error is optimized to obtain the corrected intrinsic parameters of the semi-solid-state lidar. This improves the measurement accuracy of the semi-solid-state lidar in three-dimensional space and is of great significance for the development of high-precision semi-solid-state lidar.

[0051] In one embodiment, the intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints includes the following steps:

[0052] Step 1: Set up the environment consisting of a rotating mirror semi-solid-state lidar and a planar constraint plate. Place the planar constraint plate in front of or to the side of the lidar to ensure complete coverage of the lidar's scanning range.

[0053] Step 2: The lidar scans the plane constraint plate and records the signal flight time t and the corresponding rotation angle α of the rotating mirror for each scanning point.

[0054] Step 3: Substitute the signal flight time t, the corresponding mirror rotation angle α, and the intrinsic parameters of the lidar into the lidar ranging model to obtain the three-dimensional point cloud coordinates x, y, z of the planar constraint plate.

[0055]

[0056] The coordinates of the laser beam reflected from the mirror; λ is the distance from the laser emitter to the mirror. The direction vector of the laser beam after reflection from the mirror; C: speed of light.

[0057] The relationship between the variables and intrinsic parameters in the above formula is as follows:

[0058]

[0059]

[0060]

[0061] The structural intrinsic parameters of a lidar are as follows: ρ, θ (rad): together represent the direction of the incident laser; X L ,Y L Z L : Represents the three-dimensional coordinates of the laser emitter; β (rad): Represents the mirror tilt angle; d: Represents the distance from the mirror to the origin.

[0062] Step 4, as follows Figure 1 As shown, adjust the position of the planar constraint plate and repeat steps 1-3 to obtain multiple sets of point cloud data and calculate the planar constraint error for each set:

[0063]

[0064] in

[0065]

[0066]

[0067]

[0068] cov(x,z)cov(y,x)cov(y,z)cov(z,x)cov(z,y) also have similar properties.

[0069] Step 5: Sum the planar constraint errors of each group to obtain the global planar constraint error:

[0070] Error = ∑error j 2

[0071] Due to ρ,θ,X L ,Y L Z L β and d are the structural intrinsic parameters of the lidar, from which the estimated values ​​and error range can be obtained. Therefore, by iterating through the values ​​of all intrinsic parameters within the error range, the global planar constraint error can be optimized to obtain the corrected lidar intrinsic parameters.

[0072] ρ,θ,X L ,Y L Z L ,β,d=arg minError

[0073] In one embodiment, the intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints includes the following steps: establishing a calibration environment including a semi-solid-state lidar and a planar calibration board; using the semi-solid-state lidar to scan the scanning points of the planar calibration board and recording the signal flight time and mirror rotation angle corresponding to each scanning point; inputting the signal flight time, mirror rotation angle, and intrinsic parameters of the semi-solid-state lidar into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration board; adjusting the position of the planar calibration board and using the semi-solid-state lidar to scan the scanning points of the adjusted planar calibration board to obtain multiple sets of three-dimensional point cloud data of the planar calibration board; calculating the planar constraint error of each set based on the multiple sets of three-dimensional point cloud data; calculating the global constraint error based on the planar constraint error; adjusting the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error and optimizing the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

[0074] The intrinsic parameters of a semi-solid-state lidar include: ρ, θ (rad): together representing the direction of the incident laser; X L ,Y L Z L : The three-dimensional coordinates of the laser emitter; β (rad): represents the mirror tilt angle; d: represents the distance from the mirror to the origin. The key feature is that the three-dimensional point cloud data of the planar calibration plate is calculated, including the following steps:

[0075] The reflection direction vector is calculated based on the rotation angle of the rotating mirror and the intrinsic parameters. The reflection direction vector is used to represent the direction vector of the laser after it is reflected by the mirror.

[0076] The distance information from the transmitter to the mirror and the coordinate information of the laser reflection point on the mirror are calculated based on the rotation angle of the rotating mirror and the intrinsic parameters. The distance information is used to represent the distance of the laser from the transmitter to the mirror surface, and the coordinate information is used to represent the coordinates of the laser reflection point after it hits the mirror surface.

[0077] The three-dimensional point cloud data of the planar calibration plate is calculated based on the signal flight time, reflection direction vector, distance information, and coordinate information.

[0078] The three-dimensional point cloud data of the planar calibration board is calculated based on the signal flight time, reflection direction vector, distance information, and coordinate information. The analytical expression is as follows:

[0079]

[0080] Where λ represents distance information, i.e., the distance from the laser emitter to the mirror surface; This refers to coordinate information, specifically the coordinates of the laser beam at the point of reflection on the mirror surface. t is the reflection direction vector; C is the speed of light; t is the signal flight time.

[0081] Furthermore, the planar constraint error for each set of three-dimensional point cloud data is calculated based on the following analytical expression:

[0082]

[0083] in,

[0084] cov(x,z)cov(y,x)cov(y,z)cov(z,x)cov(z,y) also have similar properties.

[0085] In one embodiment, the intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints includes the following steps: establishing a calibration environment including a semi-solid-state lidar and a planar calibration board; using the semi-solid-state lidar to scan the scanning points of the planar calibration board, recording the signal flight time and mirror rotation angle corresponding to each scanning point; inputting the signal flight time, mirror rotation angle, and intrinsic parameters of the semi-solid-state lidar into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration board; adjusting the position of the planar calibration board, using the semi-solid-state lidar to scan the scanning points of the adjusted planar calibration board to obtain multiple sets of three-dimensional point cloud data of the planar calibration board; calculating the planar constraint error for each set based on the multiple sets of three-dimensional point cloud data; calculating the global constraint error based on the planar constraint error; adjusting the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error, and optimizing the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar. Calculating the global constraint error based on the planar constraint error includes the step of summing the planar constraint errors of each set to obtain the global constraint error.

[0086] Furthermore, the modified intrinsic parameters of the semi-solid-state lidar are expressed analytically as follows:

[0087] ρ,θ,X L ,Y L Z L ,β,d=argminError

[0088] Where Error is the global constraint error, and the intrinsic parameters of the semi-solid-state lidar include: ρ, θ (rad): together representing the direction of the incident laser; X L ,Y L Z L : Represents the three-dimensional coordinates of the laser emitter; β (rad): Represents the mirror tilt angle; d: Represents the distance from the mirror to the origin.

[0089] This invention also provides an intrinsic parameter correction system for a semi-solid-state lidar based on planar constraints, comprising: a data recording module for recording the signal flight time and mirror rotation angle corresponding to each scanning point of the semi-solid-state lidar scanning the planar calibration plate; a three-dimensional point cloud data calculation module for inputting the signal flight time, the mirror rotation angle, and the intrinsic parameters of the semi-solid-state lidar into the lidar ranging model, calculating the three-dimensional point cloud data of the planar calibration plate, adjusting the position of the planar calibration plate, and using the semi-solid-state lidar to scan the scanning points of the adjusted planar calibration plate to obtain multiple sets of the three-dimensional point cloud data of the planar calibration plate; a planar constraint error calculation module for calculating the planar constraint error of each set based on the multiple sets of the three-dimensional point cloud data; and an intrinsic parameter correction module for calculating the global constraint error based on the planar constraint error, adjusting the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error, and optimizing the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

[0090] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0091] Furthermore, one embodiment of the present invention provides a computer-readable storage medium storing computer-executable instructions that are executed by a processor or controller, for example, by a processor in the above-described terminal embodiment, such that the processor performs the intrinsic parameter correction method for a planar constraint-based semi-solid-state lidar in the above-described embodiment.

[0092] Those skilled in the art will understand that all or some of the steps and systems in the methods disclosed above can be implemented as software, firmware, hardware, and suitable combinations thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, digital signal processor, or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on a computer-readable medium, which can include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and is accessible to a computer. Furthermore, as is known to those skilled in the art, communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

[0093] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

[0094] The specific embodiments of the present invention described above do not constitute a limitation on the scope of protection of the present invention. Any other corresponding changes and modifications made in accordance with the technical concept of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for intrinsic parameter correction of a semi-solid-state lidar based on planar constraints, characterized in that, Includes the following steps: A calibration environment including a semi-solid-state lidar and a planar calibration board is set up. The semi-solid-state lidar is used to scan the scanning points of the planar calibration board, and the signal flight time and mirror rotation angle corresponding to each scanning point are recorded. The signal flight time, the rotation angle of the rotating mirror, and the intrinsic parameters of the semi-solid-state lidar are input into the lidar ranging model to calculate the three-dimensional point cloud data of the planar calibration plate. The position of the planar calibration plate is adjusted, and the semi-solid-state lidar is used to scan the scanning points of the planar calibration plate after the position is adjusted, so as to obtain multiple sets of the three-dimensional point cloud data of the planar calibration plate; The planar constraint error for each group is calculated based on the multiple groups of 3D point cloud data. The global constraint error is calculated based on the planar constraint error. The intrinsic parameters of the semi-solid-state lidar are adjusted within the range of the global constraint error, and the global planar constraint error is optimized to obtain the corrected intrinsic parameters of the semi-solid-state lidar. The intrinsic parameters of the semi-solid-state lidar include: ρ, θ (rad): together representing the direction of the incident laser; The laser emitter's three-dimensional coordinates; β (rad): represents the mirror tilt angle; d: represents the distance from the mirror to the origin. The three-dimensional point cloud data of the planar calibration plate is calculated, including: The reflection direction vector is calculated based on the rotation angle of the rotating mirror and the intrinsic parameters. The reflection direction vector is used to represent the direction vector of the laser after it is reflected by the mirror. The distance information from the emitter to the mirror and the coordinate information of the laser reflection point on the mirror are calculated based on the rotation angle of the rotating mirror and the intrinsic parameters. The distance information is used to represent the distance from the emitter to the mirror surface of the rotating mirror, and the coordinate information is used to represent the coordinates of the laser reflection point after it is reflected from the mirror surface. The three-dimensional point cloud data of the planar calibration plate is calculated based on the signal flight time, the reflection direction vector, the distance information, and the coordinate information.

2. The intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints according to claim 1, characterized in that, The three-dimensional point cloud data of the planar calibration board is calculated based on the signal flight time, the reflection direction vector, the distance information, and the coordinate information, and the analytical expression is as follows: ； Wherein, λ is the distance information, that is, the distance from the laser emitter to the mirror surface; The coordinate information refers to the coordinates of the laser at the point of reflection on the mirror surface; Let be the reflection direction vector; C be the speed of light; and t be the signal flight time.

3. The intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints according to claim 2, characterized in that, The planar constraint error for each set of three-dimensional point cloud data is calculated based on the following analytical expression: 。 4. The intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints according to claim 1, characterized in that, The global constraint error is calculated based on the planar constraint error, including the following steps: The global constraint error is obtained by summing the plane constraint errors of each group.

5. The intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints according to claim 1, wherein the corrected intrinsic parameters of the semi-solid-state lidar are expressed analytically as follows: ； in, Error refers to the global constraint error. The intrinsic parameters of the semi-solid-state lidar include: ρ, θ (rad): together representing the direction of the incident laser. : Represents the position coordinates of the laser emitter; β (rad): Represents the mirror tilt angle; d: Represents the distance from the mirror to the origin.

6. An intrinsic parameter correction system for a semi-solid-state lidar based on planar constraints, characterized in that, An intrinsic parameter correction method for implementing the planar constraint-based semi-solid-state lidar according to any one of claims 1 to 5 includes: The data recording module is used to record the signal flight time and mirror rotation angle corresponding to each scanning point of the semi-solid-state lidar scanning the planar calibration plate; The three-dimensional point cloud data calculation module is used to input the signal flight time, the rotation angle of the rotating mirror and the intrinsic parameters of the semi-solid-state lidar into the lidar ranging model, calculate the three-dimensional point cloud data of the planar calibration plate, adjust the position of the planar calibration plate, and use the semi-solid-state lidar to scan the scanning points of the adjusted planar calibration plate to obtain multiple sets of the three-dimensional point cloud data of the planar calibration plate. The planar constraint error calculation module is used to calculate the planar constraint error of each group based on multiple groups of the three-dimensional point cloud data. The intrinsic parameter correction module is used to calculate the global constraint error based on the planar constraint error, adjust the intrinsic parameters of the semi-solid-state lidar within the range of the global constraint error, and optimize the global planar constraint error to obtain the corrected intrinsic parameters of the semi-solid-state lidar.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions for causing a computer to perform the intrinsic parameter correction method for a semi-solid-state lidar based on planar constraints as described in any one of claims 1 to 5.

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