CN116973892A

CN116973892A - Laser radar calibration device

Info

Publication number: CN116973892A
Application number: CN202310815709.6A
Authority: CN
Inventors: 袁灿
Original assignee: Suteng Innovation Technology Co Ltd
Current assignee: Suteng Innovation Technology Co Ltd
Priority date: 2019-04-29
Filing date: 2019-04-29
Publication date: 2023-10-31
Also published as: CN111856434A; CN111856434B

Abstract

The application relates to a laser radar calibration device. The device comprises an acquisition module, a processing module and a processing module, wherein the acquisition module is used for acquiring a transmitting power value and an echo intensity value set corresponding to a channel identifier; the selection module is used for selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value; the acquisition module is also used for acquiring a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set; and the determining module is used for determining the corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value. By adopting the scheme of the application, the accuracy of laser radar calibration can be improved.

Description

Laser radar calibration device

The present application is a divisional application of chinese application No. 201910352739.1, the foregoing of which is incorporated by reference in the present document.

Technical Field

The present application relates to the field of radar technologies, and in particular, to a laser radar calibration method, a device, a computer device, and a storage medium.

Background

Radar is an electronic device that discovers objects and determines the spatial position of the objects. The laser radar is a radar that detects a characteristic quantity such as a position and a speed of a target by emitting a laser beam. The laser radar emits laser to irradiate the target and receives the echo, so that the information such as the distance, the azimuth and the height from the target to the electromagnetic wave emitting point is obtained. Because different target objects have great influence on echo signals, such as objects with higher reflectivity, such as license plates, road signs and the like, the situation that the echo of the laser radar is saturated and cut off is easily caused, and different deviations exist in the ranging result, so that the laser radar needs to be calibrated. However, the current laser radar calibration method has the problem of inaccurate calibration results.

Disclosure of Invention

Based on the above, it is necessary to provide a laser radar calibration method, a device, a computer device and a computer storage medium capable of improving the accuracy of the calibration result, aiming at the problem that the calibration result is inaccurate.

A laser radar calibration method, the method comprising: acquiring a transmitting power value and an echo intensity value set corresponding to a channel identifier; the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmission power values, and the calibration plate comprises at least two areas with different reflectivities; each echo intensity value corresponds to a reflectivity; selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value; acquiring a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set; and determining the corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value.

In one embodiment, acquiring the transmit power value and the set of echo intensity values corresponding to the channel identifier includes: acquiring at least two transmitting power values and an echo intensity value set corresponding to the channel identifier under each transmitting power value in the at least two transmitting power values; determining a corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value, including: and determining the corresponding relation between the echo intensity value and the distance correction value under each transmission power value according to the reference distance value under each transmission power value and the measured distance value corresponding to each echo intensity value.

In one embodiment, the number of channel identifications is at least two; the laser radar calibration method further comprises the following steps: when detecting that uncalibrated channel identifiers exist in at least two channel identifiers, controlling the laser radar to switch to a channel corresponding to the next channel identifier, and continuously acquiring an echo intensity value set corresponding to the next channel identifier; and ending when detecting that the uncalibrated channel identifiers exist in the at least two channel identifiers.

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

In one embodiment, after adjusting the position of the radar according to the relative position between the laser radar channels or adjusting the angle of the radar according to the relative angle between the radar channels, the method further includes: obtaining a target angle according to 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 angle of the radar 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 positioned in the target area.

In one embodiment, the laser radar calibration method further includes: and controlling the calibration plate to move along a preset direction, so that the center point of the light spot is projected in the areas corresponding to different reflectivities on the calibration plate.

In one embodiment, determining the correspondence between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value includes: fitting according to the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve for representing the corresponding relation between the echo intensity value and the distance correction value; when the fitting coefficient of the curve meets the preset threshold condition, generating a corresponding relation between the echo intensity value and the distance correction value; and when the fitting coefficient of the curve does not meet the preset threshold condition, re-executing the step of acquiring the transmission power value.

A lidar ranging method, comprising: acquiring an echo intensity value corresponding to the channel identifier and a measuring distance between the laser radar corresponding to the channel identifier and the target object; searching a corresponding distance correction value from the corresponding relation between the echo intensity value and the distance correction value under the channel identifier according to the echo intensity value; correcting the measured distance between the laser radar and the target object according to the distance correction value;

the corresponding relation between the echo intensity value and the distance correction value under the channel identification is determined according to the reference distance value corresponding to the reference echo intensity value and the measurement distance value corresponding to each echo intensity value; the reference echo intensity value is an echo intensity value which is selected from an echo intensity value set and does not exceed a preset echo intensity value; the echo intensity value set comprises echo intensity values generated by the calibration plate according to the transmission power values, the calibration plate comprises at least two areas with different reflectivities, and each echo intensity value corresponds to one reflectivity.

A lidar calibration device, the device comprising: the acquisition module is used for acquiring the transmitting power value and the echo intensity value set corresponding to the channel identifier; the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmission power value, and the calibration plate comprises at least two areas with different reflectivities; each echo intensity value corresponds to a reflectivity;

The selection module is used for selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value;

the acquisition module is also used for acquiring a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set;

and the determining module is used for determining the corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value.

In one embodiment, the acquiring module is configured to acquire at least two transmit power values, and a set of echo intensity values corresponding to the channel identifier at each of the at least two transmit power values. The determining module is used for determining the corresponding relation between the echo intensity value and the distance correction value under each transmitting power value according to the reference distance value under each transmitting power value and the measured distance value corresponding to each echo intensity value.

In one embodiment, the number of channel identifications is at least two; the laser radar calibration device also comprises a control module, wherein the control module is used for controlling the laser radar to switch to a channel corresponding to the next channel identifier when detecting that uncalibrated channel identifiers exist in at least two channel identifiers, and continuously acquiring an echo intensity value set corresponding to the next channel identifier; and ending when detecting that the uncalibrated channel identifiers exist in the at least two channel identifiers.

In one embodiment, the control module is configured to adjust a position of the lidar according to a relative position between the lidar channels, or adjust an angle of the lidar according to a relative angle between the radar channels, so as to control the lidar to switch to a channel corresponding to a next channel identifier.

In one embodiment, the control module is further configured to obtain the target angle according to 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 angle of the laser radar 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 positioned in the target area.

In one embodiment, the control module is further configured to control the calibration plate to move along a preset direction, so that the center point of the light spot is projected in the areas corresponding to different reflectivities on the calibration plate.

In one embodiment, the determining module is configured to perform fitting processing according to the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve for representing the correspondence between the echo intensity value and the distance correction value; when the fitting coefficient of the curve meets the preset threshold condition, generating a corresponding relation between the echo intensity value and the distance correction value; and when the fitting coefficient of the curve does not meet the preset threshold condition, re-acquiring the transmitting power value by the acquisition module.

A computer device comprising a memory storing a computer program and a processor which when executing the computer program performs the steps of: acquiring a transmitting power value and an echo intensity value set corresponding to a channel identifier; the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmission power values, and the calibration plate comprises at least two areas with different reflectivities; each echo intensity value corresponds to a reflectivity; selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value; acquiring a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set; and determining the corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value.

A computer readable storage medium having stored thereon a computer program which when executed by a processor performs the steps of: acquiring a transmitting power value and an echo intensity value set corresponding to a channel identifier; the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmission power values, and the calibration plate comprises at least two areas with different reflectivities; each echo intensity value corresponds to a reflectivity; selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value; acquiring a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set; and determining the corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value.

According to the laser radar calibration method, the laser radar calibration device, the computer equipment and the storage medium, the echo intensity value sets corresponding to the transmitting power values and the channel identifiers are obtained, wherein the echo intensity value sets comprise echo intensity values generated by the calibration plate according to the transmitting power values, the calibration plate comprises at least two areas with different reflectivities, each echo intensity value corresponds to one reflectivity, and echo intensity values under different reflectivities can be obtained; the method comprises the steps of obtaining a reference distance value and a measurement distance value corresponding to each echo intensity value, determining the corresponding relation between the echo intensity value and a distance correction value according to the measurement distance value and the reference distance value, determining the distance correction value of the laser radar corresponding to the echo intensity value under different saturation or distortion degrees, improving the accuracy of a calibration result, correcting the ranging result of the laser radar, and improving the accuracy of the ranging result of the laser radar.

Drawings

FIG. 1 is an application environment diagram of a laser radar calibration method in one embodiment;

FIG. 2 is a flow chart of a laser radar calibration method according to one embodiment;

FIG. 3 is a diagram of an application environment of a laser radar calibration method according to another embodiment;

FIG. 4 is a flow chart of a laser radar calibration method according to another embodiment;

FIG. 5 is a flow chart of a laser radar ranging method according to one embodiment;

FIG. 6 is a block diagram of a lidar calibration device in one embodiment;

FIG. 7 is a block diagram of the results of a lidar ranging device in one embodiment;

fig. 8 is an internal structural diagram of a computer device in one embodiment.

Detailed Description

The present application will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present application more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the application.

The laser radar calibration method provided by the embodiment of the application can be applied to an application environment shown in figure 1. The terminal 102 performs data transmission with the lidar 104 through a network or a communication port. The lidar 104 may be placed on a calibration stage 106, wherein the calibration stage 106 may be equipped with a motor for controlling the lidar to change position. The lidar 104 may emit a detection signal and project a light spot to the calibration plate 108. The terminal 102 may be, but is not limited to, various personal computers, notebook computers, smart phones, tablet computers, and portable wearable devices, among others.

In one embodiment, as shown in fig. 2, a laser radar calibration method is provided, and the method is applied to the terminal in fig. 1 for illustration, and includes the following steps:

step 202, acquiring a transmitting power value and an echo intensity value set corresponding to a channel identifier; the echo intensity value set comprises echo intensity values generated by the calibration plate according to the transmitting power value; the calibration plate comprises at least two areas with different reflectivities; each echo intensity value corresponds to a reflectivity.

The transmitting power value may be a transmitting power value supported by the laser radar, or may be a transmitting power value preset by the terminal and supported by the laser radar. The number of radar channels in the lidar is not limited, and may be one, two or more, etc. The channel identifier is a unique identifier for distinguishing laser radar channels, and may be composed of one or more of numbers, letters, and symbols. The echo intensity is also called echo power and is the power value received by the laser radar. Reflectivity is the percentage of radiant energy reflected by an object to the total radiant energy. The calibration plate may be any object of unknown reflectivity, such as wood, steel plate, plastic plate, cement or brick, or any object of known reflectivity, such as reflective decal. The at least two regions having different reflectivities are each regions capable of producing unsaturated echoes for a detection signal of the lidar. The calibration plate may be at the same distance from the lidar. The same distance between the calibration plate and the laser radar can specifically mean that the distance between the laser radar and the object is basically the same distance in the calibration process, and certain error can exist in the same distance.

Specifically, the terminal acquires a transmitting power value of the laser radar and sends a transmitting instruction corresponding to the transmitting power value to the laser radar. And the laser radar respectively transmits detection signals to different reflectivity areas of the calibration plate according to the transmission instruction. The terminal can acquire a set of echo intensity values corresponding to the channel identification. The echo intensity value set comprises echo intensity values generated by the calibration plate according to the transmission power value. The calibration plate comprises at least two areas of different reflectivity at the same distance from the radar. Each echo intensity value corresponds to a reflectivity.

In this embodiment, the terminal starts calibration from the first channel identifier according to the preset sequence. The terminal acquires a transmitting power value and controls a detection signal corresponding to the transmitting power value of the laser radar. The terminal controls the laser radar to project the detection signal to an object corresponding to a first reflectivity of a meters away from the laser radar, and the terminal receives a first echo intensity value from the laser radar. The terminal controls the laser radar to project the detection signal to an object corresponding to the second reflectivity of the laser radar, which is a meters away, and the terminal receives a second echo intensity value from the laser radar. The terminal may obtain a first echo intensity value and a second echo intensity value, forming an echo intensity value set. And the third and fourth … … Nth echo intensity values can be obtained by the same method, so that an echo intensity value set is formed.

Step 204, selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value.

The preset echo intensity value is an echo intensity value under the measurement limit of hardware. The preset echo intensity value may be derived from an unsaturated echo waveform measurement.

Specifically, the terminal selects any echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value.

In this embodiment, the terminal may select all echo intensity values that do not exceed the preset echo intensity value from the echo intensity value set, and calculate an average value according to all echo intensity values that do not exceed the preset echo intensity value, to obtain the reference echo intensity value.

In this embodiment, the echo signal corresponding to the echo intensity value not exceeding the preset echo intensity value is a symmetrical gaussian pulse, and has a unique maximum value. And the echo of the laser radar is received by three processes of photoelectric conversion, amplification and quantization. Saturation refers to that the echo intensity exceeds the measurement limit of a hardware circuit, and the waveform obtained after conversion, amplification and quantization is caused to have larger distortion than the original waveform, and the distortion is called saturation. And saturation during amplification can lead to waveform distortion. The unsaturated standard echo is the echo when the intensity of the echo does not exceed the measurement limit of hardware, and the digital waveform obtained after the conversion of the hardware can better restore the original input waveform.

Step 206, obtaining a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set.

The measured distance value is a value calculated by the terminal after the laser radar measures the distance.

Specifically, the terminal can obtain a reference echo intensity value obtained by measuring the laser radar, and obtain a reference distance value corresponding to the reference echo intensity value according to the time difference and the light speed according to the time difference between the transmitting pulse and the echo pulse of the measuring laser radar. Or the terminal calculates the reference distance value corresponding to the echo intensity value according to the laser radar equation, the transmitting power value and the echo intensity value. Likewise, the terminal may calculate a measured distance value for each echo intensity value in the set of echo intensity values other than the reference echo intensity value.

Step 208, determining the corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value.

Specifically, there is a certain error between the reference distance value and the measured distance value. And the terminal calculates according to the reference distance value and the measured distance value corresponding to each echo intensity, and then determines the corresponding relation between the echo intensity value and the distance correction value, namely one echo intensity value corresponds to one distance correction value.

In the laser radar calibration method, the echo intensity value set corresponding to the transmitting power value and the channel identifier is obtained, wherein the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmitting power value, the calibration plate comprises at least two objects with different reflectivities, each echo intensity value corresponds to one reflectivity, and the echo intensity values under different reflectivities can be obtained; the method comprises the steps of obtaining a reference distance value and a measurement distance value corresponding to each echo intensity value, determining the corresponding relation between the echo intensity value and a distance correction value according to the measurement distance value and the reference distance value, determining the distance correction value of the laser radar corresponding to the echo intensity value under different saturation or distortion degrees, improving the accuracy of a calibration result, correcting the ranging result of the laser radar, and improving the accuracy of the ranging result of the laser radar.

In one embodiment, obtaining a set of transmit power values and echo intensity values corresponding to a channel identification includes: acquiring at least two transmitting power values and an echo intensity value set corresponding to the channel identifier under each transmitting power value in the at least two transmitting power values; determining a corresponding relation between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value, including: and determining the corresponding relation between the echo intensity value and the distance correction value under each transmission power value according to the reference distance value under each transmission power value and the measured distance value corresponding to each echo intensity value.

The at least two transmitting power values may be transmitting power values supported by at least two lidars, or may be transmitting power values preset by at least two terminals and supported by the lidars. The at least two transmit power values may be in the form of transmit power levels.

Specifically, the terminal obtains at least two transmitting power values, and an echo intensity value set corresponding to the channel identifier under each transmitting power value in the at least two transmitting power values. For example, the terminal obtains three transmission power values, and the terminal obtains the first echo intensity value to the third echo intensity value corresponding to the channel identifier 1 under the first transmission power value. And the terminal acquires fourth echo intensity values to sixth echo intensity values corresponding to the channel identifier 1 under the second transmitting power value. And the terminal acquires the seventh echo intensity value to the ninth echo intensity value corresponding to the channel identifier 1 under the third transmitting power value.

And the terminal calculates according to the reference distance value under each transmitting power value and the measured distance value corresponding to each echo intensity value, and determines the corresponding relation between the echo intensity and the distance correction value under each transmitting power value.

In this embodiment, assuming that d0 is the reference ranging value in the case of the standard echo, d0 may also be considered as the reference ranging value closest to the actual distance. d1 is a ranging value at other echo intensities, and whether the standard is unknown. The distance compensation value at this echo intensity is Δd=d0-d 1. Then Δd is present for each echo intensity. Then at the time of actual ranging, the final ranging result d=distance measurement value+distance correction value Δd. When the echo is not saturated, d0=d1, Δd=0, and then the distance measurement value is the reference distance value, and the distance correction value is 0. When the echo is saturated, d0+.d1, # d+.0. There is a deviation between the distance measurement value and the reference distance value and the deviation is Δd.

According to the laser radar calibration method, the transmission power value parameters can be increased by acquiring at least two transmission power values and the echo intensity value set corresponding to the channel identifier under each transmission power value in the at least two transmission power values, the influence of the transmission power values on the echo intensity value is eliminated according to the corresponding relation between the echo intensity value under each transmission power value and the distance correction value, and the accuracy of the calibration result is improved.

In one embodiment, the number of channel identifications is at least two; the laser radar calibration method further comprises the following steps: when the uncalibrated channel identifiers exist in the at least two channel identifiers, controlling the laser radar to switch to a channel corresponding to the next channel identifier, and continuously acquiring an echo intensity value set corresponding to the next channel identifier;

and ending when detecting that the uncalibrated channel identifiers exist in the at least two channel identifiers.

Specifically, the number of channel identities is known to the terminal. When the terminal detects that any uncalibrated channel identifier exists in the at least two channel identifiers, for example, the channel identifier has no corresponding echo intensity value set and the like, the laser radar is controlled by the motor to switch to a channel corresponding to the next channel identifier. The terminal only needs to acquire the echo intensity value set corresponding to the next channel identifier.

When the terminal detects that the uncalibrated channel identifiers do not exist in the at least two channel identifiers, for example, the channel identifiers have corresponding echo intensity value sets and the like, the laser radar calibration method is ended. Namely, when the terminal detects that all the channel identifications in the at least two channel identifications have corresponding echo intensity value sets, the laser radar calibration method is ended.

According to the laser radar calibration method, when the uncalibrated channel identifiers exist in at least two channel identifiers, the laser radar is controlled to switch to the channel corresponding to the next channel identifier, the echo intensity set corresponding to the next channel identifier is continuously acquired, the channel corresponding to each channel identifier can be calibrated, correction errors among the channels can be eliminated, and the accuracy of a calibration result is improved.

In one embodiment, as shown in fig. 3, an application environment diagram of a laser radar calibration method in another embodiment is shown. Terminal 302 is connected to industrial camera, lidar, motor 1 and motor 2, respectively, through network communication or communication interfaces. The laser radar is spaced a meters from the target plate, and a can be any positive real number. The terminal can control the whole system and collect calibration data, for example, the terminal can control a laser radar switching channel by controlling the motor 1, and the terminal can control the movement of the target plate by controlling the motor 2. The target plate is a target plate with changeable reflectivity.

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

Wherein the relative position between the lidar channels may refer to the relative distance between the lidar channels.

Specifically, the lidar may be placed on a calibration stage that contains a motor. The terminal can control the height of the calibration table and the like by controlling the motor, and control the laser radar to switch to the channel corresponding to the next channel identifier. The terminal can also control the laser radar to switch to the channel corresponding to the next channel identifier by controlling the horizontal rotation angle or the vertical rotation angle and the like of the laser radar through the motor. The terminal may cause the probe signal transmitted by the channel corresponding to the next channel identifier to be projected on the target area.

According to the laser radar calibration method, the position of the laser radar is adjusted according to the relative positions among the laser radar channels, or the angle of the laser radar is adjusted according to the relative angles among the radar channels, so that the laser radar is controlled to be switched to the channel corresponding to the next channel identifier, the position or the angle of the laser radar can be coarsely adjusted, the next channel of the laser radar is calibrated, and the laser radar calibration accuracy is improved.

In one embodiment, adjusting the position of the lidar according to the relative position between the lidar channels, and after controlling the lidar to switch to the channel corresponding to the next channel identifier, further includes: obtaining a target angle according to 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 laser radar 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 positioned in the target area.

The target area refers to a preset area to which the light spot should be projected. For example, the target area may be an area of any reflectivity in the calibration plate. The target area may be a specific point on the surface of an object, or may be any point in the area corresponding to the reflectivity. The distance between the light spot center point and the target area can be calculated according to the coordinates of the light spot center point and the coordinates of the target area after the terminal uses the industrial camera to shoot a picture containing the light spot center point and the target area, and the terminal obtains the coordinates of the light spot center point and the coordinates of the target area.

Specifically, the laser radar channel corresponding to the next channel identifier emits a detection signal to the object, and then a light spot is projected on the object. And the terminal obtains a target angle according to 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. And the terminal controls the motor of the calibration table according to the target angle to adjust the angle of the laser radar so that the center point of the light spot projected by the channel corresponding to the next channel identifier is positioned in the target area.

According to the laser radar calibration method, the target angle is obtained according to 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 the angle of the laser radar is adjusted according to the target angle, so that the center point of the light spot is positioned in the target area, the position of the laser radar can be finely adjusted, the light spot of the laser radar is positioned in the target area, and the laser radar calibration accuracy is improved.

In one embodiment, the laser radar calibration method further comprises: and controlling the calibration plate to move along a preset direction, so that the center point of the light spot is projected in the areas corresponding to different reflectivities on the calibration plate.

The calibration plate may be formed by seamless splicing of stickers with different reflectivities, for example, but not limited to, 10%, 20%, 40%, 50%, 70%, 100% reflectivity, etc. The preset direction may be a direction in which the position is changed but the vertical distance between the object and the lidar is still at the same distance. The regions corresponding to different reflectivities are, for example, regions corresponding to 10% reflectivity, regions corresponding to 20% reflectivity, and the like.

Specifically, the terminal controls the calibration plate to move along the preset direction through the motor, and the vertical distance between the calibration plate and the laser radar is not changed in the moving process, so that the center point of a light spot is projected in the areas corresponding to different reflectivities on the calibration plate.

For example, after switching channels, the spot center point is located in the area of the calibration plate where the reflectivity is lowest. 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 respectively projected in the area with the lowest reflectivity to the target area with the highest reflectivity.

According to the laser radar calibration method, the calibration plate is controlled to move along the preset direction, so that the light spot center point is projected in the areas corresponding to different reflectivities on the calibration plate, echo intensity values corresponding to the different reflectivities can be obtained, the calibration plate is directly controlled, errors caused by object offset can be reduced, and the calibration efficiency and the calibration accuracy are improved.

The fitting coefficient, also called fitting degree, is used for comparing the matching degree of the prediction result and the actual occurrence condition. The preset threshold condition refers to a threshold condition stored in the terminal. And the preset threshold condition can be set according to the requirement. For example, the preset threshold condition may be that the fitting coefficient is greater than 80%, 90% or 95%, etc., but is not limited thereto.

Specifically, according to the reference distance and the measured distance value corresponding to each echo intensity value, a distance correction value corresponding to each echo intensity value can be obtained. The distance correction value corresponding to each echo intensity value is a scattered point. And fitting according to the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve for representing the corresponding relation between the echo intensity and the distance correction value. For example, the abscissa represents the echo intensity value, and the ordinate represents the distance correction value. When the fitting coefficient of the curve meets a preset threshold condition, for example, when the fitting coefficient meets a threshold condition higher than 99%, the terminal generates a corresponding relation between the echo intensity value and the distance correction value. And when the fitting coefficient of the curve does not meet the preset threshold condition, re-executing the step of acquiring the transmission power value.

In this embodiment, the terminal may further generate a configuration file of the laser radar according to the correspondence between the echo intensity value and the distance correction value. The terminal can also obtain a corresponding relation curve of the echo intensity value and the distance correction value under each transmitting power value according to the transmitting power values.

In the laser radar calibration method, a curve for representing the corresponding relation between the echo intensity values and the distance correction values is obtained by fitting according to the reference distance values and the measured distance values corresponding to each echo intensity value, and the curve can be converted into a continuous curve from discrete points, so that the measured distance values corresponding to the acquired echo intensity values are obtained, and the ranging values of the laser radar can be corrected; when the fitting coefficient of the curve meets the preset threshold condition, a corresponding relation between the echo intensity value and the distance correction value is generated, and 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, so that correction value errors caused by accidental results can be reduced, and the accuracy of the calibration result is improved.

In one embodiment, as shown in fig. 4, a flow chart of a laser radar calibration method in another embodiment is shown. The laser radar calibration method can be applied to an application environment shown in fig. 3. The terminal adjusts the position of the laser radar through the motor 1 or adjusts the position of the target plate through the motor 2, so that the light spot projected by the first channel of the laser radar channel is positioned in the target area. The terminal obtains the emission power value, and starts the motor 2, and the target board is controlled to move under the condition of not changing the distance between the laser radar and the target board, so that the laser radar traverses all objects corresponding to different emissivity in the target board. And the terminal receives the echo intensity values to obtain an echo intensity value set. The terminal acquires a plurality of transmitting power values, so that a first channel of the laser radar traverses all the transmitting power values, and the corresponding relation between the echo intensity value and the distance correction value under each transmitting power value can be obtained. Wherein the transmit power value may be in the form of a transmit power level. The terminal obtains a plurality of transmitting power levels, so that a first channel of the laser radar traverses all the transmitting power levels, and the corresponding relation between the echo intensity value and the distance correction value under each transmitting power level can be obtained. When the terminal detects that an uncalibrated channel identifier exists, the position of the laser radar is adjusted through the motor 1, the laser radar is controlled to be switched to a channel corresponding to the next channel identifier, and the step of enabling the light spot to be in a target area is continuously executed. And when the terminal marks all channels corresponding to the channel identifiers, performing data fitting processing on the echo intensity value set corresponding to each channel identifier. And when the data fitting degree meets a preset threshold condition, the terminal generates a configuration file of the laser radar. The configuration file is used for correcting the distance measurement value during laser radar ranging. And when the data fitting degree does not meet the preset threshold condition, the terminal determines the channel identifier needing recalibration, and the step of enabling the light spot to be located in the target area is carried out again by controlling the motor 1 to switch to the channel corresponding to the channel identifier.

According to the laser radar calibration method, the light spots are located in the target area, all objects with different reflectivities are traversed, all power values are traversed, the channels corresponding to all channel identifications are calibrated, calibration data are fitted, the corresponding relation between the echo intensity values and the distance correction values can be obtained, errors caused by the reflectivities and the channels are reduced, and the laser radar calibration accuracy is improved.

In one embodiment, a laser radar calibration method includes:

step (a 1), obtaining at least two transmitting power values.

And (a 2) controlling the calibration plate to move along a preset direction, so that the center point of the light spot is projected in the areas corresponding to different reflectivities on the calibration plate.

Step (a 3), acquiring an echo intensity value set corresponding to the channel identifier under each of at least two transmitting power values, wherein the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmitting power values; the calibration plate comprises at least two areas with different reflectivities, each echo intensity value corresponds to one reflectivity, and the number of the channel identifiers is at least two.

And (a 4) selecting an echo intensity value which does not exceed a preset echo intensity value from the echo intensity value set as a reference echo intensity value.

And (a 5) acquiring a reference distance value corresponding to the reference echo intensity value and a measurement distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set.

And (a 6) when the uncalibrated channel marks exist in the at least two channel marks, adjusting the position of the laser radar according to the relative position between the laser radar channels, or adjusting the angle of the radar according to the relative angle between the radar channels, and controlling the laser radar to switch to the channel corresponding to the next channel mark.

And (a 7) obtaining a target angle according to 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 (a 8) adjusting the angle of the laser radar 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 positioned in the target area.

And (a 9) continuing to acquire an echo intensity value set corresponding to the next channel identifier.

Step (a 10), fitting according to the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve for representing the corresponding relation between the echo intensity value and the distance correction value;

Step (a 11), when the fitting coefficient of the curve meets the preset threshold condition, generating a corresponding relation between the echo intensity value and the distance correction value;

and (a 12) when the fitting coefficient of the curve does not meet the preset threshold condition, re-executing the step of acquiring the transmission power value.

In the laser radar calibration method, the echo intensity value set corresponding to the transmitting power value and the channel identifier is obtained, wherein the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmitting power value, the calibration plate comprises at least two areas with different reflectivities, each echo intensity value corresponds to one reflectivity, and the echo intensity values under different reflectivities can be obtained; the method comprises the steps of obtaining a reference distance value and a measurement distance value corresponding to each echo intensity value, determining the corresponding relation between the echo intensity value and a distance correction value according to the measurement distance value and the reference distance value, determining the distance correction value of the laser radar corresponding to the echo intensity value under different saturation or distortion degrees, improving the accuracy of a calibration result, correcting the ranging result of the laser radar, and improving the accuracy of the ranging result of the laser radar.

In one embodiment, as shown in fig. 5, a laser radar ranging method includes:

Step 502, acquiring an echo intensity value corresponding to a channel identifier and a measurement distance between a laser radar corresponding to the channel identifier and a target object;

specifically, during the use process of the laser radar, the terminal can acquire an echo intensity value corresponding to the channel identifier and a measurement distance between the laser radar corresponding to the channel identifier and the target object.

Step 504, searching a corresponding distance correction value from the corresponding relation between the echo intensity value and the distance correction value under the channel identifier according to the echo intensity value;

specifically, the terminal searches for a corresponding distance correction value from a file representing the corresponding relationship between the echo intensity value and the distance correction value under the channel identifier according to the echo intensity value corresponding to the channel identifier.

For example, the first laser radar channel receives an echo intensity value a, and the second laser radar channel receives an echo intensity value B. The terminal searches for a distance correction value C1 from the correspondence between the echo intensity value identified by the channel and the distance correction value according to a. And the terminal searches the distance correction value C2 from the corresponding relation between the echo intensity value under the second channel identifier and the distance correction value according to the B.

Step 506, correcting the measured distance between the laser radar and the target object according to the distance correction value, wherein the corresponding relation between the echo intensity value under the channel identifier and the distance correction value is determined according to 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 which is selected from an echo intensity value set and does not exceed a preset echo intensity value; the echo intensity value set comprises echo intensity values generated by the calibration plate according to the transmission power values, the calibration plate comprises at least two areas with different reflectivities, and each echo intensity value corresponds to one reflectivity.

Specifically, the terminal corrects the measured distance between the laser radar and the target object according to the distance correction value. For example, the measured distance between the laser radar and the target object is D, and the distance correction value is D0, then the corrected measured distance=d-D0.

According to the laser radar ranging method, the echo intensity value corresponding to the channel identifier and the measured distance between the laser radar and the target object corresponding to the channel identifier are obtained, the corresponding distance correction value is searched from the corresponding relation between the echo intensity value and the distance correction value under the channel identifier according to the echo intensity value, and the measured distance between the laser radar and the target object is corrected according to the distance correction value, so that the ranging error caused by echo saturation can be reduced, and the ranging accuracy and precision can be improved.

It should be understood that, although the steps in the flowcharts of fig. 2 and 5 are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited to the order of execution unless explicitly recited herein, and the steps may be executed in other orders. Moreover, at least a portion of the steps in fig. 2 and 5 may include at least two sub-steps or at least two stages, which are not necessarily performed at the same time, but may be performed at different times, and the order of execution of the sub-steps or stages is not necessarily sequential, but may be performed in turn or alternately with at least a portion of the other steps or sub-steps of other steps.

In one embodiment, as shown in fig. 6, there is provided a laser radar calibration apparatus including: an acquisition module 602, a selection module 604, and a determination module 606, wherein:

an acquisition module 602, configured to acquire a transmit power value and an echo intensity value set corresponding to a channel identifier; the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmission power values, and the calibration plate comprises at least two areas with different reflectivities; each echo intensity value corresponds to a reflectivity.

The selecting module 604 is configured to select, from the set of echo intensity values, an echo intensity value that does not exceed a preset echo intensity value as a reference echo intensity value.

The obtaining module 602 is further configured to obtain a reference distance value corresponding to the reference echo intensity value, and a measured distance value corresponding to each echo intensity value except the reference echo intensity value in the echo intensity value set.

The determining module 606 is configured to determine a correspondence between the echo intensity value and the distance correction value according to the reference distance value and the measured distance value corresponding to each echo intensity value.

In the laser radar calibration device, the echo intensity value set corresponding to the transmitting power value and the channel identifier is obtained, wherein the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmitting power value, the calibration plate comprises at least two areas with different reflectivities, each echo intensity value corresponds to one reflectivity, and the echo intensity values under different reflectivities can be obtained; the method comprises the steps of obtaining a reference distance value and a measurement distance value corresponding to each echo intensity value, determining the corresponding relation between the echo intensity value and a distance correction value according to the measurement distance value and the reference distance value, determining the distance correction value of the laser radar corresponding to the echo intensity value under different saturation or distortion degrees, improving the accuracy of a calibration result, correcting the ranging result of the laser radar, and improving the accuracy of the ranging result of the laser radar.

In one embodiment, the obtaining module 602 is configured to obtain at least two transmit power values, and a set of echo intensity values corresponding to the channel identifier at each of the at least two transmit power values. The determining module 606 is configured to determine a correspondence between the echo intensity value and the distance correction value at each transmit power value according to the reference distance value at each transmit power value and the measured distance value corresponding to each echo intensity value.

According to the laser radar calibration device, the transmission power value parameters can be increased by acquiring at least two transmission power values and the echo intensity value set corresponding to the channel identifier under each transmission power value in the at least two transmission power values, the influence of the transmission power values on the echo intensity value is eliminated according to the corresponding relation between the echo intensity value under each transmission power value and the distance correction value, and the accuracy of the calibration result is improved.

According to the laser radar calibration device, when the uncalibrated channel identifiers exist in at least two channel identifiers, the laser radar is controlled to switch to the channel corresponding to the next channel identifier, the echo intensity set corresponding to the next channel identifier is continuously acquired, the channel corresponding to each channel identifier can be calibrated, correction errors among the channels can be eliminated, and the accuracy of a calibration result is improved.

In one embodiment, the control module is configured to adjust a position of the lidar according to a relative position between the lidar channels, or adjust an angle of the lidar according to a relative angle between the radar channels, and control the lidar to switch to a channel corresponding to a next channel identifier.

According to the laser radar calibration device, the position of the laser radar is adjusted according to the relative positions among the laser radar channels, or the angle of the laser radar is adjusted according to the relative angle among the radar channels, so that the laser radar is controlled to be switched to the channel corresponding to the next channel identifier, the position of the laser radar can be coarsely adjusted, the next channel of the laser radar is calibrated, and the accuracy of laser radar calibration is improved.

According to the laser radar calibration device, the target angle is obtained according to 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 the angle of the laser radar is adjusted according to the target angle, so that the center point of the light spot is positioned in the target area, the position of the laser radar can be finely adjusted, the light spot of the laser radar is positioned in the target area, and the accuracy of laser radar calibration is improved.

According to the laser radar calibration device, the different calibration plates are controlled to move along the preset direction, so that the central point of a light spot is projected in different reflectivity areas, echo intensity values corresponding to different reflectivities can be obtained, the calibration plates are directly controlled, errors caused by object offset can be reduced, and the calibration efficiency and the calibration accuracy are improved.

In one embodiment, the determining module 606 is configured to perform a fitting process according to the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve for 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, generating a corresponding relation 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 acquiring module 602 re-acquires the transmission power value.

In the laser radar calibration device, a curve for representing the corresponding relation between the echo intensity values and the distance correction values is obtained by fitting according to the reference distance values and the measured distance values corresponding to each echo intensity value, and the curve can be converted from discrete points to continuous curves, so that the measured distance values corresponding to the acquired echo intensity values are obtained, and the ranging values of the laser radar can be corrected; when the fitting coefficient of the curve meets the preset threshold condition, a corresponding relation between the echo intensity value and the distance correction value is generated, and 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, so that correction value errors caused by accidental results can be reduced, and the accuracy of the calibration result is improved.

In one embodiment, as shown in fig. 7, there is provided a lidar ranging apparatus comprising: a data acquisition module 702, a lookup module 704, and a correction module 706, wherein:

the data acquisition module 702 is configured to acquire an echo intensity value corresponding to the channel identifier, and a measured distance between the laser radar corresponding to the channel identifier and the target object.

The searching module 704 is configured to search for a corresponding distance correction value from a corresponding relationship between the echo intensity value and the distance correction value under the channel identifier according to the echo intensity value.

The correction module 706 is configured to correct the measured distance between the laser radar and the target object according to the distance correction value, where the corresponding relationship between the echo intensity value and the distance correction value under the channel identifier is determined according to 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 which is selected from an echo intensity value set and does not exceed a preset echo intensity value; the echo intensity value set comprises echo intensity values generated by the calibration plate according to the transmission power values, the calibration plate comprises at least two areas with different reflectivities, and each echo intensity value corresponds to one reflectivity.

According to the laser radar ranging device, the echo intensity value corresponding to the channel identifier and the measured distance between the laser radar and the target object corresponding to the channel identifier are obtained, the corresponding distance correction value is searched from the corresponding relation between the echo intensity value and the distance correction value under the channel identifier according to the echo intensity value, the measured distance between the laser radar and the target object is corrected according to the distance correction value, the ranging error caused by echo saturation can be reduced, and the ranging accuracy and precision are improved.

For specific limitations of the laser radar calibration device, reference may be made to the above limitation of the laser radar calibration method, and no further description is given here. The above-mentioned laser radar calibration device may be implemented in whole or in part by software, hardware, or a combination thereof. The above modules may be embedded in hardware or may be independent of a processor in the computer device, or may be stored in software in a memory in the computer device, so that the processor may call and execute operations corresponding to the above modules.

In one embodiment, a computer device is provided, which may be a terminal, and the internal structure thereof may be as shown in fig. 8. The computer device includes a processor, a memory, a network interface, a display screen, and an input device connected by a system bus. Wherein the processor of the computer device is configured to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. 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 of the computer device is used for communicating with an external terminal through a network connection. The computer program is executed by a processor to implement a laser radar calibration method. The display screen of the computer equipment can be a liquid crystal display screen or an electronic ink display screen, and the input device of the computer equipment can be a touch layer covered on the display screen, can also be keys, a track ball or a touch pad arranged on the shell of the computer equipment, and can also be an external keyboard, a touch pad or a mouse and the like.

It will be appreciated by those skilled in the art that the structure shown in FIG. 8 is merely a block diagram of some of the structures associated with the present inventive arrangements and is not limiting of the computer device to which the present inventive arrangements may be applied, and that a particular computer device may include more or fewer components than shown, or may combine some of the components, or have a different arrangement of components.

In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the lidar calibration method described above when the computer program is executed.

In one embodiment, a computer device is provided, comprising a memory and a processor, the memory having stored therein a computer program, the processor implementing the steps of the lidar ranging method described above when the computer program is executed.

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

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

Those skilled in the art will appreciate that implementing all or part of the above described methods may be accomplished by way of a computer program stored on a non-transitory computer readable storage medium, which when executed, may comprise the steps of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in embodiments provided herein may include non-volatile and/or volatile memory. The nonvolatile 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 a variety of forms such as Static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double Data Rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous Link DRAM (SLDRAM), memory bus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), among others.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the application, which are described in detail and are not to be construed as limiting the scope of the application. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the application, which are all within the scope of the application. Accordingly, the scope of protection of the present application is to be determined by the appended claims.

Claims

1. A lidar calibration device, the device comprising:

the acquisition module is used for acquiring at least two transmission power values and an echo intensity value set corresponding to the channel identifier under each transmission power value in the at least two transmission power values; the echo intensity value set comprises echo intensity values generated by a calibration plate according to the transmitting power values, the calibration plate comprises at least two areas with different reflectivities, and each echo intensity value corresponds to one reflectivity;

and the determining module is used for determining the corresponding relation between the echo intensity value and the distance correction value under each transmitting power value according to the reference distance value under each transmitting power value and the measured distance value corresponding to each echo intensity value.

2. The lidar calibration device of claim 1, wherein the number of channel identifications is at least two;

the apparatus further comprises:

and the control module is used for controlling the laser radar to switch to a channel corresponding to the next channel identifier when detecting that uncalibrated channel identifiers exist in the at least two channel identifiers, and continuously acquiring an echo intensity value set corresponding to the next channel identifier.

3. The lidar calibration device of claim 2, the control module further to end when it is detected that there is no uncalibrated channel identity in the at least two channel identities.

4. A lidar calibration device according to claim 2 or 3, wherein the control module is specifically configured to:

and adjusting the position of the laser radar according to the relative positions among the laser radar channels, or adjusting the angle of the radar according to the relative angles among the radar channels, and controlling the laser radar to switch to the channel corresponding to the next channel identifier.

5. The lidar calibration device of claim 4, wherein the control module is further configured to

Obtaining a target angle according to 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 angle of the laser radar 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 positioned in the target area.

6. The lidar calibration device of claim 2, wherein the control module is further configured to

And controlling the calibration plate to move along a preset direction, so that the center point of the light spot is projected in the areas corresponding to different reflectivities on the calibration plate.

7. The lidar calibration device of claim 1, wherein the determination module is specifically configured to,

Fitting according to the reference distance value and the measured distance value corresponding to each echo intensity value to obtain a curve for representing the corresponding relation between the echo intensity value and the distance correction value;

when the fitting coefficient of the curve meets the preset threshold condition, generating a corresponding relation between the echo intensity value and the distance correction value;

and when the fitting coefficient of the curve does not meet the preset threshold condition, re-executing the step of acquiring the transmitting power value.

8. The laser radar calibration device according to claim 1, wherein the selection module is specifically configured to select all echo intensity values from the echo intensity value set that do not exceed a preset echo intensity value, and calculate an average value according to all echo intensity values that do not exceed the preset echo intensity value, to obtain the reference echo intensity value.

9. The laser radar calibration device according to claim 6, wherein the control module is specifically configured to control the calibration plate to move along a preset direction by using a motor, and a vertical distance between the calibration plate and the laser radar is not changed during the movement process, so that a light spot center point is projected in areas corresponding to different reflectivities on the calibration plate.