Lidar calibration device

Abstract

This application relates to a lidar calibration device. The device includes an acquisition module for acquiring a transmit power value and a set of echo intensity values ​​corresponding to a channel identifier; a selection module for selecting echo intensity values ​​from the set of echo intensity values ​​that do not exceed a preset echo intensity value as reference echo intensity values; the acquisition module is further configured to acquire a reference distance value corresponding to the reference echo intensity value, and a measurement distance value corresponding to each echo intensity value in the set of echo intensity values ​​other than the reference echo intensity value; and a determination module for determining the correspondence between echo intensity values ​​and distance correction values ​​based on the reference distance value and the measurement distance values ​​corresponding to each echo intensity value. The solution of this application can improve the accuracy of lidar calibration.

Description

[0001] This application is a divisional application of Chinese application No. 201910352739.1, the foregoing contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of radar technology, and in particular to a lidar calibration method, apparatus, computer equipment, and storage medium. Background Technology

[0003] Radar is an electronic device that detects targets and determines their spatial location. LiDAR (Light Detection and Ranging) is a type of radar that uses laser beams to detect the position, velocity, and other characteristics of targets. LiDAR illuminates a target with a laser beam and receives its echo, thereby obtaining information such as the distance, azimuth, and altitude of the target to the electromagnetic wave emission point. Because different target objects significantly affect the echo signal—for example, highly reflective objects like license plates and road signs can easily cause saturation cutoff in the LiDAR echo, leading to varying ranging results—calibration of the LiDAR is necessary. However, current LiDAR calibration methods suffer from inaccurate calibration results. Summary of the Invention

[0004] Therefore, it is necessary to provide a lidar calibration method, device, computer equipment, and computer storage medium that can improve the accuracy of calibration results to address the problem of inaccurate calibration results.

[0005] A lidar calibration method includes: acquiring a transmit power value and a set of echo intensity values ​​corresponding to a channel identifier; the echo intensity value set includes echo intensity values ​​generated by a calibration board based on the transmit power value, the calibration board including at least two regions with different reflectivities; each echo intensity value corresponds to a reflectivity; selecting echo intensity values ​​from the echo intensity value set that do not exceed a preset echo intensity value as reference echo intensity values; acquiring a reference distance value corresponding to the reference echo intensity value, and a measurement distance value corresponding to each echo intensity value in the echo intensity value set other than the reference echo intensity value; and determining the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measurement distance value corresponding to each echo intensity value.

[0006] In one embodiment, obtaining the transmit power value and the set of echo intensity values ​​corresponding to the channel identifier includes: obtaining at least two transmit power values, and the set of echo intensity values ​​corresponding to the channel identifier for each of the at least two transmit power values; determining the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value includes: determining the correspondence between the echo intensity value and the distance correction value for each transmit power value based on the reference distance value for each transmit power value and the measured distance value corresponding to each echo intensity value.

[0007] In one embodiment, the number of channel identifiers is at least two; the lidar calibration method further includes: when an uncalibrated channel identifier is detected among at least two channel identifiers, controlling the lidar to switch to the channel corresponding to the next channel identifier, and continuing to acquire the echo intensity value set corresponding to the next channel identifier; when no uncalibrated channel identifier is detected among at least two channel identifiers, the process ends.

[0008] In one embodiment, controlling the lidar to switch to the channel corresponding to the next channel identifier includes: adjusting the position of the lidar according to the relative position between lidar channels, or adjusting the angle of the lidar according to the relative angle between lidar channels, and controlling the lidar to switch to the channel corresponding to the next channel identifier.

[0009] In one embodiment, after adjusting the radar position based on the relative position between the lidar channels, or adjusting the radar angle based on the relative angle between the lidar channels, and controlling the radar to switch to the channel corresponding to the next channel identifier, the method further includes: obtaining the target angle based on a reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area; adjusting the radar angle based on the target angle so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

[0010] In one embodiment, the lidar calibration method further includes: controlling the calibration plate to move along a preset direction so that the center point of the light spot is projected onto the calibration plate in areas corresponding to different reflectivities.

[0011] In one embodiment, determining the correspondence between echo intensity values ​​and distance correction values ​​based on reference distance values ​​and measured distance values ​​corresponding to each echo intensity value includes: performing fitting processing on reference distance values ​​and measured distance values ​​corresponding to each echo intensity value to obtain a curve characterizing the correspondence between echo intensity values ​​and distance correction values; generating the correspondence between echo intensity values ​​and distance correction values ​​when the fitting coefficient of the curve meets a preset threshold condition; and re-executing the step of obtaining transmit power values ​​when the fitting coefficient of the curve does not meet the preset threshold condition.

[0012] A lidar ranging method includes: acquiring an echo intensity value corresponding to a channel identifier, and the measured distance between the lidar and the target object corresponding to the channel identifier; searching for a corresponding distance correction value from the correspondence between echo intensity values ​​and distance correction values ​​under the channel identifier based on the echo intensity value; and correcting the measured distance between the lidar and the target object based on the distance correction value.

[0013] The correspondence between the echo intensity value and the distance correction value under the channel identifier is determined based on the reference distance value corresponding to the reference echo intensity value and the measured distance value corresponding to each echo intensity value. The reference echo intensity value is an echo intensity value selected from the echo intensity value set that does not exceed a preset echo intensity value. The echo intensity value set includes the echo intensity values ​​generated by the calibration board based on the transmit power value. The calibration board includes at least two regions with different reflectivities, and each echo intensity value corresponds to a reflectivity.

[0014] A lidar calibration device includes: an acquisition module for acquiring a transmit power value and a set of echo intensity values ​​corresponding to a channel identifier; the set of echo intensity values ​​includes echo intensity values ​​generated by a calibration plate based on the transmit power value, the calibration plate including at least two regions with different reflectivities; each echo intensity value corresponds to a reflectivity;

[0015] The selection module is used to select echo intensity values ​​that do not exceed a preset echo intensity value from the set of echo intensity values ​​as reference echo intensity values;

[0016] The acquisition module is also used to acquire the reference distance value corresponding to the reference echo intensity value, and the measurement distance value corresponding to each echo intensity value other than the reference echo intensity value in the echo intensity value set;

[0017] The determination module is used to determine the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value.

[0018] In one embodiment, the acquisition module is used to acquire at least two transmit power values, and a set of echo intensity values ​​corresponding to a channel identifier for each of the at least two transmit power values. The determination module is used to determine the correspondence between the echo intensity value and the distance correction value for each transmit power value based on the reference distance value for each transmit power value and the measured distance value corresponding to each echo intensity value.

[0019] In one embodiment, the number of channel identifiers is at least two; the lidar calibration device further includes a control module, which controls the lidar to switch to the channel corresponding to the next channel identifier when an uncalibrated channel identifier is detected among at least two channel identifiers, and continues to acquire the echo intensity value set corresponding to the next channel identifier; when no uncalibrated channel identifier is detected among at least two channel identifiers, the process ends.

[0020] In one embodiment, the control module is used to adjust the position of the lidar according to the relative position between lidar channels, or to adjust the angle of the lidar according to the relative angle between lidar channels, and to control the lidar to switch to the channel corresponding to the next channel identifier.

[0021] In one embodiment, the control module is further configured to obtain the target angle based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area; and adjust the angle of the lidar according to the target angle so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

[0022] In one embodiment, the control module is also used to control the calibration plate to move along a preset direction so that the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate.

[0023] In one embodiment, the determining module is used to perform fitting processing based on the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve that characterizes the correspondence between the echo intensity value and the distance correction value; when the fitting coefficient of the curve meets the preset threshold condition, the correspondence between the echo intensity value and the distance correction value is generated; when the fitting coefficient of the curve does not meet the preset threshold condition, the acquiring module reacquires the transmit power value.

[0024] A computer device includes a memory and a processor. The memory stores a computer program, and the processor executes the computer program to perform the following steps: acquiring a transmit power value and a set of echo intensity values ​​corresponding to a channel identifier; the set of echo intensity values ​​includes echo intensity values ​​generated by a calibration board based on the transmit power value, the calibration board including at least two regions with different reflectivities; each echo intensity value corresponds to a reflectivity; selecting echo intensity values ​​from the set of echo intensity values ​​that do not exceed a preset echo intensity value as reference echo intensity values; acquiring a reference distance value corresponding to the reference echo intensity value, and a measured distance value corresponding to each echo intensity value in the set of echo intensity values ​​other than the reference echo intensity value; determining the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value.

[0025] A computer-readable storage medium storing a computer program thereon, the computer program being executed by a processor to perform the following steps: acquiring a transmit power value and a set of echo intensity values ​​corresponding to a channel identifier; the set of echo intensity values ​​includes echo intensity values ​​generated by a calibration board based on the transmit power value, the calibration board including at least two regions with different reflectivities; each echo intensity value corresponds to a reflectivity; selecting echo intensity values ​​from the set of echo intensity values ​​that do not exceed a preset echo intensity value as reference echo intensity values; acquiring a reference distance value corresponding to the reference echo intensity value, and a measured distance value corresponding to each echo intensity value in the set of echo intensity values ​​other than the reference echo intensity value; determining the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value.

[0026] The aforementioned lidar calibration method, apparatus, computer equipment, and storage medium, by acquiring a set of echo intensity values ​​corresponding to the transmit power value and channel identifier, wherein the echo intensity value set includes echo intensity values ​​generated by the calibration board based on the transmit power value, the calibration board includes at least two regions with different reflectivities, and each echo intensity value corresponds to a reflectivity, can obtain echo intensity values ​​under different reflectivities; acquiring a reference distance value and a measurement distance value corresponding to each echo intensity value, and determining the correspondence between the echo intensity value and the distance correction value based on the measurement distance value and the reference distance value, can determine the distance correction value of the lidar corresponding to the echo intensity value under different saturation or distortion degrees, thereby improving the accuracy of the calibration results and also correcting the lidar ranging results, thus improving the accuracy of the lidar ranging results. Attached Figure Description

[0027] Figure 1 This is an application environment diagram of a lidar calibration method in one embodiment;

[0028] Figure 2 This is a flowchart illustrating a lidar calibration method in one embodiment;

[0029] Figure 3 This is an application environment diagram of the lidar calibration method in another embodiment;

[0030] Figure 4 This is a flowchart illustrating the lidar calibration method in another embodiment;

[0031] Figure 5 This is a flowchart illustrating a lidar ranging method in one embodiment;

[0032] Figure 6 This is a structural block diagram of a lidar calibration device in one embodiment;

[0033] Figure 7This is a block diagram of the results of a lidar ranging device in one embodiment;

[0034] Figure 8 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0036] The lidar calibration method provided in this embodiment can be applied to, for example, Figure 1 In the application environment shown, terminal 102 transmits data to lidar 104 via a network or communication port. LiDAR 104 can be placed on calibration platform 106, which may be equipped with a motor for controlling the lidar's position. LiDAR 104 can emit detection signals and project a light spot onto calibration plate 108. Terminal 102 can be, but is not limited to, various personal computers, laptops, smartphones, tablets, and portable wearable devices.

[0037] In one embodiment, such as Figure 2 As shown, a lidar calibration method is provided, which can be applied to... Figure 1 Taking the terminal in the example, the explanation includes the following steps:

[0038] Step 202: Obtain the transmit power value and the set of echo intensity values ​​corresponding to the channel identifier; the set of echo intensity values ​​includes the echo intensity values ​​generated by the calibration board based on the transmit power value; the calibration board includes at least two regions with different reflectivities; each echo intensity value corresponds to a reflectivity.

[0039] The transmit power value can be either the transmit power value supported by the lidar or a transmit power value preset by the terminal and supported by the lidar. The number of lidar channels is unlimited; there can be one, two, or more. The channel identifier is a unique identifier used to distinguish lidar channels and can consist of one or more of numbers, letters, and symbols. Echo intensity, also known as echo power, is the power value received by the lidar. Reflectivity is the percentage of radiant energy reflected by an object out of the total radiant energy. The calibration board can be any object with unknown reflectivity, such as wood, steel plate, plastic board, cement, or brick, or any object with known reflectivity, such as reflective stickers. At least two regions with different reflectivities are areas that can generate unsaturated echoes to the lidar's detection signal. The calibration board can be at the same distance as the lidar. Specifically, "at the same distance" means that during calibration, the distance between the lidar and the object is set to be approximately the same, although this distance may have some margin of error.

[0040] Specifically, the terminal acquires the transmit power value of the lidar and sends a transmit command corresponding to that power value to the lidar. The lidar then transmits detection signals to different reflectivity regions of the calibration board according to the transmit command. The terminal can then acquire a set of echo intensity values ​​corresponding to the channel identifier. This set of echo intensity values ​​includes the echo intensity values ​​generated by the calibration board based on the transmit power value. The calibration board includes at least two regions with different reflectivities at the same distance from the lidar. Each echo intensity value corresponds to a reflectivity.

[0041] In this embodiment, the terminal calibrates according to a preset order, starting with the first channel identifier. The terminal acquires a transmission power value and controls the detection signal corresponding to the LiDAR transmission power value. The terminal controls the LiDAR to project the detection signal onto an object with a first reflectivity at a distance of 'a' meters from the LiDAR, and the terminal receives the first echo intensity value from the LiDAR. The terminal controls the LiDAR to project the detection signal onto an object with a second reflectivity at a distance of 'a' meters from the LiDAR, and the terminal receives the second echo intensity value from the LiDAR. The terminal can acquire the first and second echo intensity values ​​to form an echo intensity value set. Similarly, the third, fourth, ..., Nth echo intensity values ​​can be obtained, forming an echo intensity value set.

[0042] Step 204: Select echo intensity values ​​that do not exceed the preset echo intensity value from the echo intensity value set as reference echo intensity values.

[0043] The preset echo intensity value is the echo intensity value under the measurement limits of the hardware. The preset echo intensity value can be obtained from measurements of an unsaturated echo waveform.

[0044] Specifically, the terminal selects any echo intensity value from the set of echo intensity values ​​that does not exceed a preset echo intensity value as a reference echo intensity value.

[0045] In this embodiment, the terminal can select all echo intensity values ​​that do not exceed the preset echo intensity value from the echo intensity value set, and calculate the average value of all echo intensity values ​​that do not exceed the preset echo intensity value to obtain the reference echo intensity value.

[0046] In this embodiment, the echo signal corresponding to the echo intensity value that does not exceed the preset echo intensity value is a symmetrical Gaussian pulse with a unique maximum value. The echo reception of a lidar involves three processes: photoelectric conversion, amplification, and quantization. Saturation occurs when the echo intensity exceeds the measurement limit of the hardware circuit, resulting in a significantly distorted waveform after conversion, amplification, and quantization compared to the original waveform. This distortion is called saturation. Saturation during amplification leads to waveform distortion. An unsaturated standard echo refers to the echo when the echo intensity does not exceed the measurement limit of the hardware. In this case, the digitized waveform obtained after hardware conversion can better reproduce the original input waveform.

[0047] Step 206: Obtain the reference distance value corresponding to the reference echo intensity value, and the measurement distance value corresponding to each echo intensity value other than the reference echo intensity value in the echo intensity value set.

[0048] The measured distance value refers to the value calculated by the terminal after the lidar measures the distance.

[0049] Specifically, the terminal can acquire the reference echo intensity value measured by the lidar, and based on the time difference between the lidar's transmitted pulse and the echo pulse, calculate the reference distance value corresponding to that echo intensity value using the time difference and the speed of light. Alternatively, the terminal can calculate the reference distance value corresponding to that echo intensity value based on the lidar equation, the transmitted power value, and the echo intensity value. Similarly, the terminal can calculate the measurement distance value corresponding to each echo intensity value in the echo intensity value set, excluding the reference echo intensity value.

[0050] Step 208: Determine the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value.

[0051] Specifically, there is a certain error between the reference distance value and the measured distance value. After the terminal performs calculations based on the reference distance value and the measured distance value corresponding to each echo intensity, it determines the correspondence between the echo intensity value and the distance correction value, that is, one echo intensity value corresponds to one distance correction value.

[0052] In the aforementioned lidar calibration method, by acquiring the set of echo intensity values ​​corresponding to the transmit power value and channel identifier, where the echo intensity value set includes the echo intensity values ​​generated by the calibration board based on the transmit power value, and the calibration board includes at least two objects with different reflectivities, each echo intensity value corresponds to a reflectivity, thus obtaining echo intensity values ​​under different reflectivities; acquiring the reference distance value and the measurement distance value corresponding to each echo intensity value, and determining the correspondence between the echo intensity value and the distance correction value based on the measurement distance value and the reference distance value, it is possible to determine the distance correction value of the lidar corresponding to the echo intensity value under different saturation or distortion degrees, thereby improving the accuracy of the calibration results and also correcting the lidar ranging results, thus improving the accuracy of the lidar ranging results.

[0053] In one embodiment, obtaining the transmit power value and the set of echo intensity values ​​corresponding to the channel identifier includes: obtaining at least two transmit power values, and the set of echo intensity values ​​corresponding to the channel identifier for each of the at least two transmit power values; determining the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value includes: determining the correspondence between the echo intensity value and the distance correction value for each transmit power value based on the reference distance value for each transmit power value and the measured distance value corresponding to each echo intensity value.

[0054] The at least two transmit power values ​​can be transmit power values ​​supported by at least two lidar sensors, or they can be transmit power values ​​preset by the terminal and supported by the lidar sensors. These at least two transmit power values ​​can be presented in the form of transmit power levels.

[0055] Specifically, the terminal acquires at least two transmit power values, and a set of echo intensity values ​​corresponding to the channel identifier under each of the at least two transmit power values. For example, if the terminal acquires three transmit power values, it acquires the first to third echo intensity values ​​corresponding to channel identifier 1 under the first transmit power value. The terminal acquires the fourth to sixth echo intensity values ​​corresponding to channel identifier 1 under the second transmit power value. The terminal acquires the seventh to ninth echo intensity values ​​corresponding to channel identifier 1 under the third transmit power value.

[0056] The terminal calculates the correspondence between the echo intensity and the distance correction value for each transmit power value based on the reference distance value for each transmit power value and the measured distance value corresponding to each echo intensity value.

[0057] In this embodiment, d0 is assumed to be the reference ranging value under standard echo conditions, which can also be considered as the reference ranging value closest to the actual distance. d1 is the ranging value under other echo intensities, and whether it is standard is unknown. Then, the distance compensation value under this echo intensity is Δd = d0 - d1. Therefore, Δd exists for different echo intensities. In actual ranging, the final ranging result D = measured distance + distance correction value Δd. When the echo is not saturated, d0 = d1, Δd = 0, so the measured distance is the reference distance value, and the distance correction value is 0. When the echo is saturated, d0 ≠ d1, Δd ≠ 0. Therefore, there is a deviation between the measured distance and the reference distance value, and the deviation is Δd.

[0058] In the above-mentioned lidar calibration method, by acquiring at least two transmit power values ​​and the set of echo intensity values ​​corresponding to the channel identifier under each of the at least two transmit power values, the transmit power value parameter can be increased. Based on the correspondence between the echo intensity value and the distance correction value under each transmit power value, the influence of the transmit power value on the echo intensity value can be eliminated, thereby improving the accuracy of the calibration results.

[0059] In one embodiment, the number of channel identifiers is at least two; the lidar calibration method further includes: when an uncalibrated channel identifier is detected among the at least two channel identifiers, controlling the lidar to switch to the channel corresponding to the next channel identifier, and continuing to acquire the echo intensity value set corresponding to the next channel identifier;

[0060] The process ends when at least two channel identifiers are found to be free of unlabeled channel identifiers.

[0061] Specifically, the terminal knows the number of channel identifiers. When the terminal detects that any of the at least two channel identifiers is unlabeled (e.g., the channel identifier has no corresponding echo intensity value set), it switches the LiDAR to the channel corresponding to the next channel identifier via motor control. The terminal only needs to obtain the echo intensity value set corresponding to the next channel identifier.

[0062] The lidar calibration method ends when the terminal detects that there is no uncalibrated channel identifier among the at least two channel identifiers, for example, when the channel identifier has a corresponding set of echo intensity values. In other words, the lidar calibration method ends when the terminal detects that all channel identifiers among the at least two channel identifiers have a corresponding set of echo intensity values.

[0063] In the above-mentioned lidar calibration method, when an uncalibrated channel identifier is detected among at least two channel identifiers, the lidar is controlled to switch to the channel corresponding to the next channel identifier and continue to acquire the echo intensity set corresponding to the next channel identifier. This method can calibrate the channel corresponding to each channel identifier, eliminate correction errors between channels, and improve the accuracy of the calibration results.

[0064] In one embodiment, such as Figure 3 The diagram shows the application environment of the lidar calibration method in another embodiment. Terminal 302 is connected to the industrial camera, lidar, motor 1, and motor 2 via network communication or a communication interface. The lidar is a meter away from the target plate, where a can be any positive real number. The terminal can control the entire system and acquire calibration data. For example, the terminal can control motor 1 to switch the lidar channel, and control motor 2 to move the target plate. The target plate has a variable reflectivity.

[0065] In one embodiment, controlling the lidar to switch to the channel corresponding to the next channel identifier includes: adjusting the position of the lidar according to the relative position between lidar channels, or adjusting the angle of the lidar according to the relative angle between lidar channels, and controlling the lidar to switch to the channel corresponding to the next channel identifier.

[0066] The relative position between lidar channels can refer to the relative distance between lidar channels.

[0067] Specifically, the lidar can be placed on a calibration platform, which contains a motor. The terminal can control the height of the calibration platform, etc., by controlling the motor, and control the lidar to switch to the channel corresponding to the next channel marker. The terminal can also control the horizontal or vertical rotation angle of the lidar, etc., by controlling the lidar to switch to the channel corresponding to the next channel marker. The terminal can then project the detection signal emitted by the channel corresponding to the next channel marker onto the target area.

[0068] In the above-mentioned lidar calibration method, the position of the lidar is adjusted according to the relative position between lidar channels, or the angle of the lidar is adjusted according to the relative angle between lidar channels, and the lidar is controlled to switch to the next channel corresponding to the channel identifier. This method can coarsely adjust the position or angle of the lidar and calibrate the next channel of the lidar, thereby improving the accuracy of lidar calibration.

[0069] In one embodiment, after adjusting the position of the lidar according to the relative position between lidar channels and controlling the lidar to switch to the channel corresponding to the next channel identifier, the method further includes: obtaining the target angle based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area; and adjusting the position of the lidar according to the target angle so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

[0070] The target area refers to the preset area where the light spot should be projected. For example, the target area could be any region of reflectivity on a calibration board. The target area could be a specific point on the surface of an object, or any point within a region corresponding to a certain reflectivity. The distance between the center point of the light spot and the target area can be calculated by the terminal using an industrial camera to capture an image containing both the center point and the target area, obtaining the coordinates of the center point and the target area, and then calculating the distance between them.

[0071] Specifically, when the lidar channel corresponding to the next channel identifier emits a detection signal towards the object, a light spot will be projected onto the object. The terminal obtains the target angle based on the acquired reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area. The terminal then controls the motor of the calibration stage to adjust the angle of the lidar according to the target angle, so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

[0072] In the above-mentioned lidar calibration method, the target angle is obtained based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area. The lidar angle is adjusted according to the target angle so that the center point of the light spot is located in the target area. This allows for fine-tuning of the lidar position, ensuring that the lidar light spot is located in the target area, thereby improving the accuracy of lidar calibration.

[0073] In one embodiment, the lidar calibration method further includes: controlling the calibration plate to move along a preset direction so that the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate.

[0074] For example, the calibration board can be seamlessly pieced together from stickers with different reflectivities, such as 10%, 20%, 40%, 50%, 70%, or 100%, but not limited to these. The preset direction can be a direction where the position changes, but the vertical distance between the object and the LiDAR remains the same. Different reflectivities correspond to different areas, such as areas with a 10% reflectivity, areas with a 20% reflectivity, etc.

[0075] Specifically, the terminal controls the calibration plate to move along a preset direction via a motor. During the movement, the vertical distance between the calibration plate and the lidar remains unchanged, so that the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate.

[0076] For example, after switching channels, the center point of the light spot is located in the area with the lowest reflectivity on the calibration plate. Then the terminal controls the calibration plate to move along a preset direction, for example, from the area with the lowest reflectivity to the area with the highest reflectivity, so that the center point of the light spot is projected onto the target area from the area with the lowest reflectivity to the area with the highest reflectivity.

[0077] In the above-mentioned lidar calibration method, by controlling the calibration plate to move along a preset direction, the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate, and the echo intensity values ​​corresponding to different reflectivities can be obtained. Furthermore, by directly controlling the calibration plate, the error caused by object offset can be reduced, and the calibration efficiency and accuracy can be improved.

[0078] In one embodiment, determining the correspondence between echo intensity values ​​and distance correction values ​​based on reference distance values ​​and measured distance values ​​corresponding to each echo intensity value includes: performing fitting processing on reference distance values ​​and measured distance values ​​corresponding to each echo intensity value to obtain a curve characterizing the correspondence between echo intensity values ​​and distance correction values; generating the correspondence between echo intensity values ​​and distance correction values ​​when the fitting coefficient of the curve meets a preset threshold condition; and re-executing the step of obtaining transmit power values ​​when the fitting coefficient of the curve does not meet the preset threshold condition.

[0079] The fitting coefficient, also known as the degree of fit, is used to compare the degree of agreement between the predicted results and the actual occurrence. Preset threshold conditions refer to threshold conditions stored in the terminal. These preset threshold conditions can be set according to needs. For example, preset threshold conditions can be fitting coefficients greater than 80%, 90%, or 95%, etc., and are not limited to these.

[0080] Specifically, based on the reference distance and the measured distance corresponding to each echo intensity value, a distance correction value corresponding to each echo intensity value can be obtained. This distance correction value for each echo intensity value is a scatter plot. A curve representing the relationship between echo intensity and distance correction value is obtained by fitting the reference distance value and the measured distance corresponding to each echo intensity value. For example, the horizontal axis represents the echo intensity value, and the vertical axis represents the distance correction value. When the fitting coefficient of the curve meets a preset threshold condition, such as a threshold condition higher than 99%, the terminal generates the correspondence between the echo intensity value and the distance correction value. When the fitting coefficient of the curve does not meet the preset threshold condition, the step of obtaining the transmit power value is re-executed.

[0081] In this embodiment, the terminal can also generate a lidar configuration file based on the correspondence between echo intensity values ​​and range correction values. The terminal can also obtain a curve showing the correspondence between echo intensity values ​​and range correction values ​​for each transmit power value.

[0082] In the aforementioned lidar calibration method, a curve representing the correspondence between echo intensity values ​​and distance correction values ​​is obtained by fitting the reference distance value and the measured distance value corresponding to each echo intensity value. This curve can transform discrete points into continuous curves, thus obtaining measured distance values ​​not limited to the acquired echo intensity values, which can correct the lidar's ranging values. When the curve fitting coefficient meets the preset threshold condition, the correspondence between echo intensity values ​​and distance correction values ​​is generated. When the curve fitting coefficient does not meet the preset threshold condition, the step of acquiring the transmit power value is re-executed, which can reduce the error in correction values ​​caused by accidental results and improve the accuracy of calibration results.

[0083] In one embodiment, such as Figure 4 The diagram shown is a flowchart of a lidar calibration method in another embodiment. This lidar calibration method can be applied to, for example... Figure 3 In the application environment shown, the terminal adjusts the position of the lidar via motor 1 or the target plate via motor 2, ensuring that the light spot projected by the first channel of the lidar is located in the target area. The terminal acquires the transmission power value and starts motor 2, controlling the target plate to move without changing the distance between the lidar and the target plate, allowing the lidar to traverse all objects on the target plate corresponding to different emissivity. The terminal receives the echo intensity value, obtaining a set of echo intensity values. By acquiring multiple transmission power values ​​and traversing all transmission power values ​​with the first channel of the lidar, the correspondence between the echo intensity value and the distance correction value under each transmission power value can be obtained. The transmission power value can be presented in the form of transmission power levels. That is, by acquiring multiple transmission power levels and traversing all transmission power levels with the first channel of the lidar, the correspondence between the echo intensity value and the distance correction value under each transmission power level can be obtained. When the terminal detects an unmarked channel identifier, it adjusts the lidar position via motor 1, controlling the lidar to switch to the channel corresponding to the next channel identifier, continuing the process of placing the light spot in the target area. Once the terminal has calibrated all channels corresponding to the channel identifiers, it performs data fitting processing on the echo intensity value set corresponding to each channel identifier. When the data fitting degree meets the preset threshold condition, the terminal generates a configuration file for the lidar. This configuration file is used to correct the distance measurement value during lidar ranging. When the data fitting degree does not meet the preset threshold condition, the terminal determines the channel identifier that needs to be recalibrated and switches to the channel corresponding to the channel identifier by controlling motor 1, and re-executes the step of positioning the light spot in the target area.

[0084] In the above-mentioned lidar calibration method, by placing the light spot in the target area, traversing all objects with different reflectivities, traversing all power values, calibrating the channels corresponding to all channel identifiers, and fitting the calibration data, the correspondence between the echo intensity value and the distance correction value can be obtained, and the error caused by reflectivity and channel can be reduced, thereby improving the accuracy of lidar calibration.

[0085] In one embodiment, a lidar calibration method includes:

[0086] Step (a1): Obtain at least two transmit power values.

[0087] Step (a2): Control the calibration plate to move along a preset direction so that the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate.

[0088] Step (a3) ​​obtains a set of echo intensity values ​​corresponding to the channel identifier for each of the at least two transmit power values. The set of echo intensity values ​​includes the echo intensity values ​​generated by the calibration board based on the transmit power values. The calibration board includes at least two regions with different reflectivities, and each echo intensity value corresponds to a reflectivity. The number of channel identifiers is at least two.

[0089] Step (a4): Select echo intensity values ​​that do not exceed the preset echo intensity value from the echo intensity value set as reference echo intensity values.

[0090] Step (a5): Obtain the reference distance value corresponding to the reference echo intensity value, and the measurement distance value corresponding to each echo intensity value other than the reference echo intensity value in the echo intensity value set.

[0091] Step (a6): When an unmarked channel identifier is detected among at least two channel identifiers, the position of the lidar is adjusted according to the relative position between the lidar channels, or the angle of the lidar is adjusted according to the relative angle between the lidar channels, and the lidar is controlled to switch to the channel corresponding to the next channel identifier.

[0092] Step (a7): The target angle is obtained based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area.

[0093] Step (a8): Adjust the angle of the lidar according to the target angle so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

[0094] Step (a9) continues to obtain the set of echo intensity values ​​corresponding to the next channel identifier.

[0095] Step (a10): Fit the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve that characterizes the correspondence between the echo intensity value and the distance correction value;

[0096] Step (a11): When the fitting coefficient of the curve meets the preset threshold condition, the correspondence between the echo intensity value and the distance correction value is generated.

[0097] Step (a12): If the fitting coefficient of the curve does not meet the preset threshold condition, the step of obtaining the transmission power value is re-executed.

[0098] In the aforementioned lidar calibration method, by acquiring the set of echo intensity values ​​corresponding to the transmit power value and channel identifier, where the echo intensity value set includes the echo intensity values ​​generated by the calibration board based on the transmit power value, and the calibration board includes at least two regions with different reflectivities, each echo intensity value corresponds to a reflectivity, thus obtaining echo intensity values ​​under different reflectivities; acquiring the reference distance value and the measurement distance value corresponding to each echo intensity value, and determining the correspondence between the echo intensity value and the distance correction value based on the measurement distance value and the reference distance value, it is possible to determine the distance correction value of the lidar corresponding to the echo intensity value under different saturation or distortion degrees, thereby improving the accuracy of the calibration results and also correcting the lidar ranging results, thus improving the accuracy of the lidar ranging results.

[0099] In one embodiment, such as Figure 5 As shown, a lidar ranging method includes:

[0100] Step 502: Obtain the echo intensity value corresponding to the channel identifier, and the measurement distance between the lidar and the target object corresponding to the channel identifier;

[0101] Specifically, during use, the terminal can obtain the echo intensity value corresponding to the channel identifier, as well as the measurement distance between the lidar and the target object corresponding to the channel identifier.

[0102] Step 504: Based on the echo intensity value, find the corresponding distance correction value from the correspondence between echo intensity value and distance correction value under the channel identifier;

[0103] Specifically, the terminal searches for the corresponding distance correction value from a file that represents the correspondence between echo intensity values ​​and distance correction values ​​under a channel identifier, based on the echo intensity value corresponding to the channel identifier.

[0104] For example, if the echo intensity value received by lidar channel one is A, and the echo intensity value received by lidar channel two is B, then the terminal will look up the distance correction value C1 from the correspondence between echo intensity values ​​and distance correction values ​​under channel identifier A. The terminal will look up the distance correction value C2 from the correspondence between echo intensity values ​​and distance correction values ​​under channel identifier two.

[0105] Step 506: Correct the measured distance between the lidar and the target object according to the distance correction value. The correspondence between the echo intensity value under the channel identifier and the distance correction value is determined based on the reference distance value corresponding to the reference echo intensity value and the measured distance value corresponding to each echo intensity value. The reference echo intensity value is an echo intensity value selected from the echo intensity value set that does not exceed a preset echo intensity value. The echo intensity value set includes the echo intensity values ​​generated by the calibration board according to the transmission power value. The calibration board includes at least two regions with different reflectivities, and each echo intensity value corresponds to a reflectivity.

[0106] Specifically, the terminal corrects the measured distance between the lidar and the target object based on the distance correction value. For example, if the measured distance between the lidar and the target object is D, and the distance correction value is d0, then the corrected measured distance = D - d0.

[0107] In the above-mentioned lidar ranging method, by acquiring the echo intensity value corresponding to the channel identifier and the measured distance between the lidar and the target object corresponding to the channel identifier, the corresponding distance correction value is found from the correspondence between the echo intensity value and the distance correction value under the channel identifier. The measured distance between the lidar and the target object is corrected according to the distance correction value. This can reduce the ranging error caused by echo saturation and improve the accuracy and precision of ranging.

[0108] It should be understood that, although Figure 2 and Figure 5 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 2 and Figure 5 At least some of the steps in the process may include at least two sub-steps or at least two stages. These sub-steps or stages are not necessarily executed at the same time, but may be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0109] In one embodiment, such as Figure 6As shown, a lidar calibration device is provided, comprising: an acquisition module 602, a selection module 604, and a determination module 606, wherein:

[0110] The acquisition module 602 is used to acquire the transmit power value and the echo intensity value set corresponding to the channel identifier; the echo intensity value set includes the echo intensity value generated by the calibration board based on the transmit power value, and the calibration board includes at least two regions with different reflectivities; each echo intensity value corresponds to a reflectivity.

[0111] The selection module 604 is used to select echo intensity values ​​that do not exceed a preset echo intensity value from the echo intensity value set as reference echo intensity values.

[0112] The acquisition module 602 is also used to acquire the reference distance value corresponding to the reference echo intensity value, and the measurement distance value corresponding to each echo intensity value other than the reference echo intensity value in the echo intensity value set.

[0113] The determination module 606 is used to determine the correspondence between the echo intensity value and the distance correction value based on the reference distance value and the measured distance value corresponding to each echo intensity value.

[0114] In the aforementioned lidar calibration device, by acquiring the set of echo intensity values ​​corresponding to the transmit power value and channel identifier, wherein the echo intensity value set includes the echo intensity values ​​generated by the calibration plate based on the transmit power value, and the calibration plate includes at least two regions with different reflectivities, each echo intensity value corresponding to a reflectivity, it is possible to obtain echo intensity values ​​under different reflectivities; by acquiring the reference distance value and the measurement distance value corresponding to each echo intensity value, and by determining the correspondence between the echo intensity value and the distance correction value based on the measurement distance value and the reference distance value, it is possible to determine the distance correction value of the lidar corresponding to the echo intensity value under different saturation or distortion degrees, thereby improving the accuracy of the calibration results and correcting the lidar ranging results, thus improving the accuracy of the lidar ranging results.

[0115] In one embodiment, the acquisition module 602 is used to acquire at least two transmit power values, and a set of echo intensity values ​​corresponding to the channel identifier for each of the at least two transmit power values. The determination module 606 is used to determine the correspondence between the echo intensity value and the distance correction value for each transmit power value based on the reference distance value for each transmit power value and the measured distance value corresponding to each echo intensity value.

[0116] In the aforementioned lidar calibration device, by acquiring at least two transmit power values ​​and a set of echo intensity values ​​corresponding to the channel identifier under each of the at least two transmit power values, the transmit power value parameter can be increased. Based on the correspondence between the echo intensity value and the distance correction value under each transmit power value, the influence of the transmit power value on the echo intensity value can be eliminated, thereby improving the accuracy of the calibration results.

[0117] In one embodiment, the number of channel identifiers is at least two; the lidar calibration device further includes a control module, which is used to control the lidar to switch to the channel corresponding to the next channel identifier when an uncalibrated channel identifier is detected among at least two channel identifiers, and continue to acquire the echo intensity value set corresponding to the next channel identifier; and to end when no uncalibrated channel identifier is detected among at least two channel identifiers.

[0118] In the aforementioned lidar calibration device, when an uncalibrated channel identifier is detected among at least two channel identifiers, the lidar is controlled to switch to the channel corresponding to the next channel identifier and continue to acquire the echo intensity set corresponding to the next channel identifier. This can calibrate the channel corresponding to each channel identifier, eliminate correction errors between channels, and improve the accuracy of the calibration results.

[0119] In one embodiment, the control module is used to adjust the position of the lidar according to the relative position between lidar channels, or to adjust the angle of the lidar according to the relative angle between lidar channels, and to control the lidar to switch to the channel corresponding to the next channel identifier.

[0120] In the aforementioned lidar calibration device, the position of the lidar is adjusted according to the relative position between lidar channels, or the angle of the lidar is adjusted according to the relative angle between lidar channels, and the lidar is controlled to switch to the channel corresponding to the next channel identifier. This allows for coarse adjustment of the lidar position and calibration of the next lidar channel, thereby improving the accuracy of lidar calibration.

[0121] In one embodiment, the control module is further configured to obtain the target angle based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area; and adjust the angle of the lidar according to the target angle so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

[0122] In the aforementioned lidar calibration device, the target angle is obtained based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area. The angle of the lidar is adjusted according to the target angle so that the center point of the light spot is located in the target area. This allows for fine-tuning of the lidar position, ensuring that the lidar light spot is located in the target area and improving the accuracy of lidar calibration.

[0123] In one embodiment, the control module is also used to control the calibration plate to move along a preset direction so that the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate.

[0124] In the aforementioned lidar calibration device, by controlling different calibration plates to move along a preset direction, the center point of the light spot is projected onto different reflectivity regions, thereby obtaining echo intensity values ​​corresponding to different reflectivities. Furthermore, by directly controlling the calibration plates, errors caused by object offset can be reduced, thus improving calibration efficiency and accuracy.

[0125] In one embodiment, the determining module 606 is used to perform fitting processing based on the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve characterizing the correspondence between the echo intensity value and the distance correction value; when the fitting coefficient of the curve meets the preset threshold condition, the correspondence between the echo intensity value and the distance correction value is generated; when the fitting coefficient of the curve does not meet the preset threshold condition, the acquiring module 602 reacquires the transmit power value.

[0126] In the aforementioned lidar calibration device, a curve representing the correspondence between echo intensity values ​​and distance correction values ​​is obtained by fitting the reference distance value and the measured distance value corresponding to each echo intensity value. This curve can be transformed from discrete points into a continuous curve, thereby obtaining a measured distance value corresponding to a value not limited to the acquired echo intensity value, which can correct the lidar's ranging value. When the fitting coefficient of the curve meets the preset threshold condition, the correspondence between the echo intensity value and the distance correction value is generated. When the fitting coefficient of the curve does not meet the preset threshold condition, the step of acquiring the transmission power value is re-executed, which can reduce the error in the correction value caused by accidental results and improve the accuracy of the calibration results.

[0127] In one embodiment, such as Figure 7 As shown, a lidar ranging device is provided, including: a data acquisition module 702, a search module 704, and a correction module 706, wherein:

[0128] The data acquisition module 702 is used to acquire the echo intensity value corresponding to the channel identifier, as well as the measurement distance between the lidar and the target object corresponding to the channel identifier.

[0129] The lookup module 704 is used to look up the corresponding distance correction value from the correspondence between echo intensity values ​​and distance correction values ​​under the channel identifier based on the echo intensity value.

[0130] The correction module 706 is used to correct the measured distance between the lidar and the target object according to the distance correction value. The correspondence between the echo intensity value under the channel identifier and the distance correction value is determined based on the reference distance value corresponding to the reference echo intensity value and the measured distance value corresponding to each echo intensity value. The reference echo intensity value is an echo intensity value selected from the echo intensity value set that does not exceed a preset echo intensity value. The echo intensity value set includes the echo intensity values ​​generated by the calibration board according to the transmit power value. The calibration board includes at least two regions with different reflectivities, and each echo intensity value corresponds to a reflectivity.

[0131] The aforementioned lidar ranging device acquires the echo intensity value corresponding to the channel identifier and the measured distance between the lidar and the target object corresponding to the channel identifier. Based on the echo intensity value, it searches for the corresponding distance correction value from the correspondence between the echo intensity value and the distance correction value under the channel identifier, and corrects the measured distance between the lidar and the target object based on the distance correction value. This reduces the ranging error caused by echo saturation and improves the accuracy and precision of ranging.

[0132] Specific limitations regarding the lidar calibration device can be found in the limitations of the lidar calibration method described above, and will not be repeated here. Each module in the aforementioned lidar calibration device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0133] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 8 As shown, the computer device includes a processor, memory, network interface, display screen, and input devices connected via a system bus. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage media. The network interface is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements a laser radar calibration method. The display screen can be an LCD screen or an e-ink screen. The input devices can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0134] Those skilled in the art will understand that Figure 8The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0135] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described lidar calibration method.

[0136] In one embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps of the above-described lidar ranging method.

[0137] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described lidar calibration method.

[0138] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described lidar ranging method.

[0139] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0140] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0141] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A lidar calibration device, characterized in that, The device includes: The acquisition module is used to acquire at least two transmit power values, and a set of echo intensity values ​​corresponding to the channel identifier under each of the at least two transmit power values; the set of echo intensity values ​​includes echo intensity values ​​generated by the calibration board according to the transmit power values, the calibration board includes at least two regions with different reflectivities at the same distance from the lidar, and each echo intensity value corresponds to a reflectivity; The selection module is used to select echo intensity values ​​that do not exceed a preset echo intensity value from the set of echo intensity values ​​as reference echo intensity values; The acquisition module is also used to acquire the reference distance value corresponding to the reference echo intensity value, and the measurement distance value corresponding to each echo intensity value other than the reference echo intensity value in the echo intensity value set; The determination module is used to determine the correspondence between the echo intensity value and the distance correction value under each transmit power value based on the reference distance value under each transmit power value and the measured distance value corresponding to each echo intensity value.

2. The lidar calibration device according to claim 1, characterized in that, The number of channel identifiers is at least two; The device further includes: The control module is used to control the lidar to switch to the channel corresponding to the next channel identifier when an unlabeled channel identifier is detected among the at least two channel identifiers, and to continue to acquire the echo intensity value set corresponding to the next channel identifier.

3. The lidar calibration device according to claim 2, wherein the control module is further configured to terminate when it is detected that there is no uncalibrated channel identifier among the at least two channel identifiers.

4. The lidar calibration device according to claim 2 or 3, characterized in that, The control module is specifically used for: The position of the lidar is adjusted according to the relative position between the lidar channels, or the angle of the lidar is adjusted according to the relative angle between the lidar channels, and the lidar is controlled to switch to the channel corresponding to the next channel identifier.

5. The lidar calibration device according to claim 4, characterized in that, The control module is also used for The target angle is obtained based on the reference distance value and the distance between the center point of the light spot projected by the channel corresponding to the next channel identifier and the target area; The angle of the lidar is adjusted according to the target angle so that the center point of the light spot projected by the channel corresponding to the next channel identifier is located in the target area.

6. The lidar calibration device according to claim 2, characterized in that, The control module is also used for The calibration plate is controlled to move along a preset direction so that the center point of the light spot is projected onto the area corresponding to different reflectivities on the calibration plate.

7. The lidar calibration device according to claim 1, characterized in that, The determining module is specifically used for, A curve representing the correspondence between echo intensity values ​​and distance correction values ​​is obtained by fitting the reference distance value and the measured distance value corresponding to each echo intensity value. When the fitting coefficient of the curve meets the preset threshold condition, the correspondence between the echo intensity value and the distance correction value is generated; When the fitting coefficient of the curve does not meet the preset threshold condition, the step of obtaining the transmission power value is re-executed, wherein the preset threshold condition is that the fitting coefficient is greater than 80%, 90%, or 95%.

8. The lidar calibration device according to claim 1, characterized in that, The selection module is specifically used to select all echo intensity values ​​that do not exceed a preset echo intensity value from the set of echo intensity values, and to calculate the average value of all echo intensity values ​​that do not exceed the preset echo intensity value to obtain the reference echo intensity value.

9. The lidar calibration device according to claim 6, characterized in that, The control module is specifically used to control the calibration plate to move along a preset direction via a motor. During the movement, the vertical distance between the calibration plate and the lidar does not change, so that the center point of the light spot is projected onto the calibration plate within the area corresponding to different reflectivities.

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