A method and apparatus for lidar signal correction

Abstract

The application provides a laser radar signal correction method and device, according to the overlapping degree of the transmitting field of view and the receiving field of view of the laser radar, the receiving area is divided into a blind area, a transition area and a bright area. The effective receiving range of the blind area, the transition area and the bright area is calculated respectively, and the cumulative distribution function of the laser spot energy in the effective receiving range is calculated, and the correction coefficient of each receiving area is calculated according to the cumulative distribution function. According to the correction coefficient, the original laser radar equation is corrected to obtain a corrected signal, and the change of the intensity of the corrected signal with the distance is consistent with the actual measurement. The measurement distance of the laser radar equation obtained by the correction method of the application can be based on the corrected laser radar equation to establish a model, according to different measurement environments, adjust the parameters of the laser radar, reduce the influence of the environment on the measurement result, and improve the accuracy of the measurement result.

Description

Technical Field

[0001] This application relates to the field of lidar technology, and in particular to a lidar signal correction method and apparatus. Background Technology

[0002] When measuring the distance to a target, the pulsed laser of the lidar emits a laser beam. The laser beam hits the target and is reflected by the target to form an echo signal. The lidar detector receives the echo signal and calculates the distance to the target based on the received echo signal.

[0003] Considering only area targets, according to the law of radiative transfer, the echo intensity of the received laser radar signal follows an inverse square law with respect to the target distance, monotonically decreasing with increasing distance. However, for coaxial laser radar, the centers of the transmitting and receiving lenses overlap, the optomechanical structure of the transmitting lens obstructs the receiving field of view, and the energy of the laser spot is not uniformly distributed. This causes the echo intensity to initially increase and then decrease in practical applications, which does not conform to the traditional laser radar equations calculated based on the law of radiative transfer. Consequently, the target distance measured using traditional laser radar equations is inaccurate. Summary of the Invention

[0004] This application provides a lidar signal correction method and apparatus to solve the problem of inaccurate target distance measurement using traditional lidar equations.

[0005] On the one hand, this application provides a lidar signal correction method, including:

[0006] The parameters of the lidar are obtained, including the radius of the emitting lens, the radius of the receiving lens, the width of the outer ring mechanism of the emitting lens, the laser divergence angle, and the receiving field of view.

[0007] Based on the transmitting and receiving fields of view of the lidar, the receiving area is divided into blind zone, transition zone, and bright zone.

[0008] The effective receiving range of the lidar within the receiving area is calculated based on the lidar parameters and the blind zone, the transition zone, and the bright zone.

[0009] Based on the effective receiving range, calculate the cumulative distribution function of the laser spot energy within the receiving area.

[0010] The correction coefficient is calculated based on the cumulative distribution function.

[0011] The lidar equation is corrected according to the correction coefficient to obtain the correction signal.

[0012] Based on different receiving areas, correction coefficients are obtained according to the laser spot energy distribution. These coefficients are then used to correct the lidar equation, resulting in a corrected echo signal. The corrected signal intensity distribution with distance conforms to actual measurement patterns, making the measurement results more accurate. A model can be built based on the corrected lidar equation, and the lidar parameters can be adjusted according to different measurement environments to reduce the impact of the environment on the measurement results.

[0013] Optionally, the blind zone is the area where the transmitting field of view and the receiving field of view do not overlap, the transition zone is the area where the transmitting field of view and the receiving field of view partially overlap, and the bright zone is the area where the transmitting field of view and the receiving field of view completely overlap.

[0014] Optionally, the step of dividing the receiving area into a blind zone, a transition zone, and a bright zone based on the transmitting and receiving fields of view of the lidar includes:

[0015] The blind zone boundary distance and the transition zone boundary distance are calculated based on the lidar parameters. The blind zone boundary distance is the distance between the lidar and the interface between the blind zone and the transition zone, and the transition zone boundary distance is the distance between the lidar and the interface between the transition zone and the illuminated zone.

[0016] The receiving area is divided into the blind zone, the transition zone, and the illuminated zone according to the distance between the blind zone boundary and the distance between the transition zone boundary.

[0017] The receiving area is divided according to the degree of overlap between the transmitting and receiving fields of the lidar, which facilitates the calculation of correction coefficients for different receiving areas.

[0018] Optionally, the blind zone boundary distance and transition zone boundary distance can be calculated based on the lidar parameters according to the following formula:

[0019]

[0020]

[0021] Where h1 is the distance to the blind zone boundary, h2 is the distance to the transition zone boundary, L is the width of the outer ring mechanism of the emitting lens, t is the laser divergence angle, k is the receiving field of view angle, and d is the radius of the emitting lens.

[0022] The boundary distance represents the range of each receiving area.

[0023] Optionally, the effective receiving range of the lidar within the receiving area is calculated based on the lidar parameters and the blind zone, the transition zone, and the bright zone, including:

[0024] Obtain the distance x1 between the inner boundary of the receiving field of view and the optical axis at a distance h, and the radius x2 of the transmitting field of view.

[0025] If the target to be tested is in the blind zone, then the effective receiving range is 0;

[0026] If the target to be measured is in the transition zone, then the effective receiving range is an annular region with an outer radius of x2 and an inner radius of x1.

[0027] If the target to be measured is in the bright area, then the effective receiving range is a circular area with a radius of x2.

[0028] Optionally, obtaining the distance x1 between the inner boundary of the receiving field of view and the optical axis at a distance h and the radius x2 of the transmitting field of view includes:

[0029] Calculate x1 and x2 according to the following formula:

[0030]

[0031] x2 = d + h × tan t;

[0032] Where h is the distance to the target to be measured, L is the width of the outer ring mechanism of the emitting lens, t is the laser divergence angle, k is the receiving field of view angle, and d is the radius of the emitting lens.

[0033] Optionally, calculating the cumulative distribution function of the laser spot energy within the receiving area includes:

[0034] The probability density function for obtaining the energy of the laser spot.

[0035] Integrating the probability density function yields the cumulative distribution function CDF(h,r) of the laser spot energy.

[0036] Where r is the distance between a spot and the optical axis within the cross-section of the laser spot at distance h.

[0037] Optionally, the correction coefficient is calculated based on the cumulative distribution function, including:

[0038] The correction coefficient E is calculated based on the transition zone and the bright zone, using the following formula:

[0039]

[0040] Optionally, the lidar equation is corrected according to the correction coefficients to obtain a correction signal, including:

[0041] The equation for obtaining the lidar is:

[0042]

[0043] Among them, P r P represents the laser power received by the lidar. t η is the laser power emitted by the lidar. o Let ρ be the efficiency of the lidar optical system, ρ be the surface reflectivity of the target, and T be the efficiency of the lidar optical system. a For one-way atmospheric transmittance, A r This represents the effective receiving area of ​​the lidar.

[0044] The corrected signal is obtained by correcting the lidar equation according to the following formula:

[0045]

[0046] Among them, P rm The laser power of the correction signal is denoted as .

[0047] On the other hand, this application provides a lidar signal correction device, comprising:

[0048] The data acquisition module is configured to acquire lidar parameters, including the radius of the emitting lens, the radius of the receiving lens, the width of the outer ring mechanism of the emitting lens, the laser divergence angle, and the receiving field of view.

[0049] The judgment module is configured to divide the receiving area into blind zone, transition zone and bright zone based on the transmitting and receiving fields of view of the lidar.

[0050] The calculation module is configured as follows:

[0051] The effective receiving range of the lidar within the receiving area is calculated based on the lidar parameters and the blind zone, the transition zone, and the bright zone.

[0052] Based on the effective receiving range, calculate the cumulative distribution function of the laser spot energy within the receiving area;

[0053] Calculate the correction coefficient based on the cumulative distribution function;

[0054] The lidar equation is corrected according to the correction coefficient to obtain the correction signal.

[0055] This application provides a lidar signal correction method and apparatus. The receiving area is divided into a blind zone, a transition zone, and a bright zone based on the overlap between the lidar's transmitting and receiving fields of view. The effective receiving range of each receiving zone is calculated, and the cumulative distribution function of the laser spot energy within the effective receiving range is also calculated. Correction coefficients for each receiving zone are calculated based on the cumulative distribution function. The original lidar equation is then corrected using these correction coefficients to obtain a corrected signal. The intensity of the corrected signal varies with distance in accordance with actual measurements. The lidar equation obtained through this correction method allows for distance measurement. A model can be built based on the corrected lidar equation, and the lidar parameters can be adjusted according to different measurement environments to reduce the impact of the environment on the measurement results and improve the accuracy of the measurement results. Attached Figure Description

[0056] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] Figure 1 A schematic diagram of a coaxial lidar optomechanical structure provided in an embodiment of this application;

[0058] Figure 2 This application provides a schematic diagram of the overlapping field of view of a coaxial lidar without considering obstruction, as provided in an embodiment of the present application.

[0059] Figure 3 A schematic diagram of the overlapping field of view of a coaxial lidar considering occlusion is provided for an embodiment of this application;

[0060] Figure 4 A simplified schematic diagram of the overlapping field of view of a coaxial lidar considering occlusion, provided as an embodiment of this application;

[0061] Figure 5 A schematic diagram of the energy distribution of a Gaussian beam spot is provided for an embodiment of this application;

[0062] Figure 6 A schematic diagram of the change curve of lidar echo signal intensity with distance is provided for an embodiment of this application;

[0063] Figure 7 A schematic diagram of the backscattered echo intensity of fog suppression provided in an embodiment of this application;

[0064] Figure 8 This is a schematic diagram of a lidar signal correction device provided in an embodiment of this application. Detailed Implementation

[0065] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0066] In a coaxial lidar, the centers of the transmitting and receiving lenses are on the same axis. (See [link]) Figure 1 This application provides a schematic diagram of the optomechanical structure of a coaxial lidar. A mechanical structure (hereinafter referred to as the outer ring mechanism) is provided around the outer ring of the emitting lens, and the emitting lens is embedded in the center of the receiving lens through the outer ring mechanism. For area targets, when measuring the distance to the target, the emitted laser light passes through the emitting lens and is emitted, forming an emission field of view. The emitted laser light is reflected by the target within the emission field of view, forming an echo signal. The echo signal is received by the detector through the receiving lens. The distance to the target can be obtained based on the echo signal and the lidar equation.

[0067] The traditional lidar equation derived from the radiative transfer law is:

[0068] Among them, P r P represents the laser power received by the lidar and the intensity of the echo signal. t η is the laser power emitted by the lidar. o Let ρ be the efficiency of the lidar optical system, ρ be the surface reflectivity of the target, and T be the efficiency of the lidar optical system. a For one-way atmospheric transmittance, A r The effective receiving area is the area on which the lidar effectively receives the echo signal (hereinafter referred to as the effective receiving area), and h is the distance to the target being measured.

[0069] The intensity P of the echo signal can be derived from the traditional lidar equation. r The distance h between the target and the target follows the inverse square law, meaning the echo signal intensity decreases monotonically with increasing distance. However, in coaxial lidar, the outer ring mechanism of the transmitting lens obstructs the receiving field of view, affecting the effective receiving range. Furthermore, within the effective receiving range, the laser spot is not uniformly distributed, causing the actual echo signal intensity to first increase and then decrease with increasing distance. Consequently, the distance measured according to the traditional lidar equation is inaccurate.

[0070] To address the above issues, this application provides a signal correction method and apparatus based on coaxial lidar. By correcting the laser spot energy of the received echo signal, a corrected lidar equation and a corrected signal are obtained. The intensity of the corrected echo signal varies with distance in line with the actual measurement results, and the distance measured according to the corrected lidar equation is more accurate.

[0071] In this embodiment of the application, a coaxial lidar, without considering the obstruction of the receiving field of view by the outer ring mechanism of the transmitting lens, has the transmitting and receiving fields of view as shown below. Figure 2 Above the transmitting lens, the area between boundary lines 01 and 02 is the transmitting field of view. Above the receiving lens, the area between boundary lines 11 and 21, and between boundary lines 12 and 22 is the receiving field of view. Only when the transmitting and receiving fields of view overlap can the echo signal reflected from the target be received by the receiving lens. In this embodiment, the effective receiving range is the area in the plane at a distance h from the lidar where the transmitting and receiving fields of view overlap.

[0072] Because the outer ring mechanism of the transmitting lens can obstruct the receiving field of view, in practical applications, the receiving field of view is not as... Figure 2 As shown, therefore, the receiving field of view needs to be corrected. See also Figure 3 This application provides a schematic diagram of field-of-view overlap for a coaxial lidar considering obstruction. Boundary line 11 is corrected to boundary line 31, and boundary line 12 is corrected to boundary line 32 based on the outer ring mechanism of the transmitting lens. Typically, the radius D of the receiving lens is greater than d + L + b × tan k, where d is the radius of the transmitting lens, L is the width of the outer ring mechanism, b is the height of the outer ring mechanism, and k is the receiving field-of-view angle. Since the receiving field-of-view angle is greater than the laser divergence angle, the outer boundary line of the receiving field of view will not affect the overlap between the transmitting and receiving fields of view. Therefore, boundary line 21 can be simplified to boundary line 41, and boundary line 22 can be simplified to boundary line 42. Based on the corrected receiving field of view, for... Figure 3 Simplified, a simplified schematic diagram of the field of view overlap of a coaxial lidar considering occlusion, as provided in this application embodiment, is obtained. See [link / reference]. Figure 4 .

[0073] Below, based on Figure 4 This application provides a detailed description of the lidar signal correction method according to embodiments of the present application. Figure 4 As can be seen, with the change of distance, the transmitting field of view and the receiving field of view can have three situations: no overlap, partial overlap, and complete overlap. The degree of overlap between the transmitting field of view and the receiving field of view is different, and the corresponding receiving area is also different. For subsequent calculations, it is necessary to correct the receiving area corresponding to different overlap situations. Therefore, it is necessary to divide the receiving area.

[0074] To divide the receiving area, it is first necessary to obtain the parameters of the coaxial LiDAR (hereinafter referred to as LiDAR parameters), which include the transmitting lens radius d, the receiving lens radius D, the outer ring mechanism width L of the transmitting lens, the laser divergence angle t, and the receiving field of view angle k. The laser divergence angle t is the angle between the boundary line 01 (boundary line 02) and the vertical direction, and the receiving field of view angle k is the angle between the boundary line 31 (boundary line 32) and the vertical direction. According to the overlapping degree of the transmitting field of view and the receiving field of view, the receiving area can be divided into a blind zone, a transition zone, and a clear zone. The blind zone is an area where the transmitting field of view and the receiving field of view do not overlap, the transition zone is an area where the transmitting field of view and the receiving field of view partially overlap, and the clear zone is an area where the transmitting field of view and the receiving field of view completely overlap.

[0075] To distinguish each receiving area, it is necessary to calculate the boundary distance of the blind zone and the boundary distance of the transition zone. The boundary distance h1 of the blind zone is the distance between the interface of the blind zone and the transition zone and the LiDAR, and the boundary distance h2 of the transition zone is the distance between the interface of the transition zone and the clear zone and the LiDAR. The receiving area is divided into the blind zone, the transition zone, and the clear zone according to the boundary distance of the blind zone and the boundary distance of the transition zone. See Figure 4 , the boundary distance of the blind zone can be calculated through geometric relationships the boundary distance of the transition zone

[0076] After the receiving area is divided, the effective receiving range of each receiving area is calculated respectively. The effective receiving range of the LiDAR varies with the distance h of the target to be measured. First, the distance x1 between the inner boundary of the receiving field of view at the distance h and the optical axis and the radius x2 of the transmitting field of view are obtained, which can be calculated according to the geometric relationship x2=d+h×tant, wherein the inner boundaries of the receiving field of view are the boundary line 31 and the boundary line 32. When h≤h1, that is, the target to be measured is in the blind zone, the transmitting field of view and the receiving field of view do not overlap, and the receiving lens cannot receive the echo signal, and the effective receiving range is 0 at this time; when h1<h<h2, that is, the target to be measured is in the transition zone, the reflected transmitting laser partially overlaps with the receiving field of view, and the effective receiving range at this time is an annular area, the inner circle radius of the annular area is x1, and the outer circle radius is x2; when h≥h2, that is, the target to be measured is in the clear zone, the echo signal after the transmitting laser is reflected is completely received by the receiving field of view, which is equivalent to x1 being 0 at this time, and the effective receiving range of the clear zone is a circular area with a radius of x2.

[0077] Next, a correction coefficient is calculated, and the lidar equation is corrected using the correction coefficient to obtain a corrected signal. First, the probability density function PDF(h,r) of the laser spot energy is calculated, an integration operation is performed on the probability density function to obtain the cumulative distribution function CDF(h,r) of the laser spot, and then the correction coefficient is calculated according to the cumulative distribution function. Here, r is the distance between a certain point on the laser spot in the cross-section of the laser spot at distance h and the optical axis.

[0078] In an embodiment, taking a Gaussian distribution of laser spot energy as an example, refer to Figure 5 , which is a schematic diagram of the energy distribution of a Gaussian beam spot provided by an embodiment of the present application, the probability density function of the laser spot where ω(h) is the beam waist radius of the laser beam, E0 is the energy at the center of the laser spot at distance h=0, and in the embodiment of the present application, the value of E0 is 1. The cumulative distribution function of the laser spot is

[0079] Next, the correction coefficient is calculated according to the cumulative distribution function. When h1<h<h2, the probability of the laser spot energy distribution within the effective receiving range of the transition region, that is, the correction coefficient, can be derived according to the definition of the cumulative distribution function as [CDF(h,x2)-CDF(h,-x2)]-[CDF(h,x1)-CDF(h,-x1)]. Similarly, when h≥h2, the correction coefficient is CDF(h,x2)-CDF(h,-x2). The correction coefficient E calculated according to different receiving areas is:

[0080]

[0081] Here, since the receiving lens cannot receive the echo signal when the target to be measured is in the blind zone, the correction coefficient of the blind zone is not considered in the embodiment of the present application.

[0082] Multiply the correction coefficient by the original lidar equation P t to correct the lidar equation, and obtain the corrected signal P rm , with the formula as follows:

[0083]

[0084] Here, P rm is the laser power of the corrected signal. Refer to Figure 6 , which is a schematic diagram of the variation curve of lidar echo signal intensity with distance provided by an embodiment of the present application, and the corrected echo signal intensity conforms to the law of first increasing and then decreasing with distance. The distance of the target to be measured calculated according to the corrected lidar equation is more accurate.

[0085] In one implementation, a model is established based on the corrected lidar equation, which can predict the curve of echo signal intensity changing with distance. The lidar parameters can be adjusted according to the predicted curve to obtain a lidar system that meets the measurement requirements.

[0086] In one implementation, a model can be built based on the corrected lidar equations. The lidar parameters can be adjusted according to different measurement environments, such as rain, snow, and fog, to reduce the impact of the environment on the measurement results. For example, in foggy conditions, the fog in the air will backscatter the emitted laser, forming backscattered echo signals. Ranging under these conditions will lead to inaccurate results; therefore, it is necessary to adjust the lidar parameters to suppress the intensity of the fog backscattered echo signals. See also... Figure 7 This is a schematic diagram of the backscattered echo intensity of fog as provided in an embodiment of this application. Figure 7 It can be seen that by increasing the focal length of the receiving lens, the intensity of the backscattered echo from the fog can be suppressed, reducing its impact on the measurement results.

[0087] See Figure 8 This application also provides a lidar signal correction device, comprising:

[0088] The data acquisition module is configured to acquire lidar parameters, including the radius of the emitting lens, the radius of the receiving lens, the width of the outer ring mechanism of the emitting lens, the laser divergence angle, and the receiving field of view.

[0089] The judgment module is configured to divide the receiving area into blind zone, transition zone and bright zone based on the transmitting and receiving fields of view of the lidar.

[0090] The calculation module is configured as follows:

[0091] The effective receiving range of the lidar within the receiving area is calculated based on the lidar parameters and the blind zone, the transition zone, and the bright zone.

[0092] Based on the effective receiving range, calculate the cumulative distribution function of the laser spot energy within the receiving area;

[0093] Calculate the correction coefficient based on the cumulative distribution function;

[0094] The lidar equation is corrected according to the correction coefficient to obtain the correction signal.

[0095] The lidar signal correction method and apparatus provided in this application divide the receiving area into a blind zone, a transition zone, and a bright zone based on the overlap between the lidar's transmitting and receiving fields of view. The effective receiving range of each zone is calculated, along with the cumulative distribution function of the laser spot energy within that effective receiving range. Correction coefficients for each receiving zone are then calculated based on these cumulative distribution functions. The original lidar equation is corrected using these correction coefficients to obtain a corrected signal. The intensity of the corrected signal varies with distance in accordance with actual measurements. The lidar equation obtained through this correction method allows for distance measurement. A model can be built based on the corrected lidar equation, and the lidar parameters can be adjusted according to different measurement environments to reduce the impact of the environment on the measurement results and improve the accuracy of the measurement results.

[0096] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A method for correcting lidar signals, characterized in that, include: Acquire lidar parameters, including the radius of the emitting lens, the radius of the receiving lens, the width of the outer ring mechanism of the emitting lens, the laser divergence angle, and the receiving field of view. Based on the transmitting and receiving fields of view of the lidar, the receiving area is divided into a blind zone, a transition zone, and a bright zone, including: The blind zone boundary distance and the transition zone boundary distance are calculated based on the lidar parameters; the blind zone boundary distance is the distance between the lidar and the interface between the blind zone and the transition zone; the transition zone boundary distance is the distance between the lidar and the interface between the transition zone and the illuminated zone. The receiving area is divided into the blind zone, the transition zone, and the visible zone according to the distance between the blind zone boundary and the distance between the transition zone boundary; The blind zone boundary distance and the transition zone boundary distance are calculated based on the lidar parameters using the following formula: ； ； in, The distance to the boundary of the blind zone. The distance to the boundary of the transition zone. The width of the outer ring mechanism of the transmitting lens. The laser divergence angle is... The receiving field of view angle The radius of the emitting lens; The effective receiving range of the lidar within the receiving area is calculated based on the lidar parameters and the blind zone, the transition zone, and the bright zone, including: Get The distance between the inner boundary of the receiving field of view at the specified distance and the optical axis. and the radius of the emission field of view ; If the target to be tested is in the blind zone, then the effective receiving range is 0; If the target to be measured is in the transition zone, then the effective receiving range is: outer radius of... The inner radius is A circular region; If the target to be measured is in the bright area, then the effective receiving range is: radius of A circular area; Get The distance between the inner boundary of the receiving field of view at the specified distance and the optical axis. and the radius of the emission field of view ,include: Calculate according to the following formula and : ； ； in, The distance to the target to be measured. The width of the outer ring mechanism of the transmitting lens. The laser divergence angle is... The receiving field of view angle The radius of the emitting lens; Based on the effective receiving range, calculate the cumulative distribution function of the laser spot energy within the receiving area; Calculate the correction coefficient based on the cumulative distribution function; The lidar equation is corrected according to the correction coefficient to obtain the correction signal.

2. The lidar signal correction method according to claim 1, characterized in that, include: The blind zone is the area where the transmitting field of view and the receiving field of view do not overlap; The transition zone is the area where the transmitting field of view and the receiving field of view partially overlap. The bright area is the region where the transmitting field of view and the receiving field of view completely overlap.

3. The lidar signal correction method according to claim 1, characterized in that, Calculating the cumulative distribution function of the laser spot energy within the receiving area includes: The probability density function for obtaining the energy of the laser spot; Integrating the probability density function yields the cumulative distribution function of the laser spot energy. ; in, for The distance between a spot and the optical axis within the cross-section of a laser beam.

4. The lidar signal correction method according to claim 3, characterized in that, The correction coefficient is calculated based on the cumulative distribution function, including: Calculate the correction coefficient based on the transition zone and the bright zone. The formula is:

5. The lidar signal correction method according to claim 4, characterized in that, The lidar equation is corrected according to the correction coefficients to obtain the correction signal, including: The equation for obtaining the lidar is: ； in, The laser power received by the lidar. This refers to the laser power emitted by the lidar. For the efficiency of lidar optical systems, The surface reflectivity of the target object is given. This refers to the atmospheric transmittance in a single pass. The effective receiving area of ​​the lidar; The corrected signal is obtained by correcting the lidar equation according to the following formula: ； in, The laser power of the correction signal is denoted as .

6. A laser radar signal correction device, characterized in that, include: The data acquisition module is configured to acquire lidar parameters, including the radius of the emitting lens, the radius of the receiving lens, the width of the outer ring mechanism of the emitting lens, the laser divergence angle, and the receiving field of view. The judgment module is configured to divide the receiving area into a blind zone, a transition zone, and a bright zone based on the transmitting and receiving fields of view of the lidar, including: The blind zone boundary distance and the transition zone boundary distance are calculated based on the lidar parameters; the blind zone boundary distance is the distance between the lidar and the interface between the blind zone and the transition zone; the transition zone boundary distance is the distance between the lidar and the interface between the transition zone and the illuminated zone. The receiving area is divided into the blind zone, the transition zone, and the visible zone according to the distance between the blind zone boundary and the distance between the transition zone boundary; The blind zone boundary distance and the transition zone boundary distance are calculated based on the lidar parameters using the following formula: ； ； in, The distance to the boundary of the blind zone. The distance to the boundary of the transition zone. The width of the outer ring mechanism of the transmitting lens. The laser divergence angle is... The receiving field of view angle The radius of the emitting lens; The calculation module is configured as follows: The effective receiving range of the lidar within the receiving area is calculated based on the lidar parameters and the blind zone, the transition zone, and the bright zone, including: Get The distance between the inner boundary of the receiving field of view at the specified distance and the optical axis. and the radius of the emission field of view ; If the target to be tested is in the blind zone, then the effective receiving range is 0; If the target to be measured is in the transition zone, then the effective receiving range is: outer radius of... The inner radius is A circular region; If the target to be measured is in the bright area, then the effective receiving range is: radius of A circular area; Get The distance between the inner boundary of the receiving field of view at the specified distance and the optical axis. and the radius of the emission field of view ,include: Calculate according to the following formula and : ； ； in, The distance to the target to be measured. The width of the outer ring mechanism of the transmitting lens. The laser divergence angle is... The receiving field of view angle The radius of the emitting lens; Based on the effective receiving range, calculate the cumulative distribution function of the laser spot energy within the receiving area; Calculate the correction coefficient based on the cumulative distribution function; The lidar equation is corrected according to the correction coefficient to obtain the correction signal.

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