Automatic Calibration Method and System for Relative Deviation of Azimuth Angle in Multi-Mode Millimeter-Wave Radar

Abstract

The present invention discloses a method and system for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes, determining a reference mode and a mode to be corrected, and a common detection area of the reference mode and the mode to be corrected; determining a statistical area based on the common detection area, dividing the statistical area into grids, and counting the number of valid detection points of the reference mode and the mode to be corrected in each grid; comparing the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area under the reference mode and the mode to be corrected with a preset threshold, determining the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result, and correcting the azimuth angle of the detection points under the mode to be corrected. The method of the present invention can achieve the purpose of compensating the relative angle measurement deviation between different modes, thereby improving the continuity of the traces between different modes and effectively improving the overall quality of the track.

Description

Technical Field

[0001] The present invention relates to the technical field of millimeter-wave radar, and particularly to a method and system for automatically correcting the relative deviation of azimuth angles in multiple modes of a millimeter-wave radar. Background Art

[0002] Millimeter-wave radar plays an extremely important role in multiple fields such as automotive safety, autonomous driving, and intelligent transportation. In actual applications, in order to achieve blind-zone-free coverage in multiple distance segments, a millimeter-wave radar system usually operates in combination with multiple modes. Each mode covers a different distance segment, and in order to achieve blind-zone-free coverage, the distance segments covered by different modes will overlap, which is called a common detection area.

[0003] However, since different modes usually use different antenna boards or different transceiver methods, and the antenna parameter configurations, amplitude-phase factors, hardware performances, etc. corresponding to different antenna boards or transceiver methods are different, there will inevitably be relative deviations in the angle measurement results between different modes. This is not conducive to the fusion and tracking of detection information between different modes, thus affecting the formation of tracks. Summary of the Invention

[0004] The present application provides a method and system for automatically correcting the relative deviation of azimuth angles in multiple modes of a millimeter-wave radar to solve the problem of relative deviation in the angle measurement results between different modes of an existing millimeter-wave radar system.

[0005] According to a first aspect, in one embodiment, a method for automatically correcting the relative deviation of azimuth angles in multiple modes of a millimeter-wave radar is provided. The method includes:

[0006] Determine a reference mode and a mode to be corrected, and the common detection area of the reference mode and the mode to be corrected;

[0007] Based on the common detection area, determine a statistical area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid;

[0008] Compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area under the reference mode and the mode to be corrected with a preset threshold, and determine the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result;

[0009] Based on the azimuth angle deviation, correct the azimuth angle of the detection points under the mode to be corrected.

[0010] Further, determining a reference mode and a mode to be corrected, and the common detection area of the reference mode and the mode to be corrected specifically includes:

[0011] Select the mode with relatively higher angular measurement accuracy as the reference mode and the mode with relatively lower angular measurement accuracy as the mode to be corrected from at least two modes with a common detection area.

[0012] Further, determine a statistical area based on the common detection area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid. Specifically, it includes:

[0013] Select a statistical area from the common detection area. The abscissa range of the statistical area is X min ~X max and the ordinate range is Y min ~Y max ;

[0014] In the Cartesian rectangular coordinate system formed with the radar as the origin, evenly divide the two dimensions of the abscissa range and the ordinate range of the statistical area into K and L grids respectively, or in the polar coordinate system formed with the radar as the origin, evenly divide the two dimensions of the radial distance coordinate range and the azimuth angle coordinate range of the statistical area into K and L grids respectively; regard the dimension divided into K grids as the first coordinate dimension and the dimension divided into L grids as the second coordinate dimension;

[0015] Screen the detection points whose signal-to-noise ratio is greater than the preset threshold and the radial velocity exceeds the preset value in each frame falling into the statistical area as valid detection points.

[0016] Further, compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area under the reference mode and the mode to be corrected with a preset threshold, and determine the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result. Specifically, it includes:

[0017] Under the reference mode and the mode to be corrected respectively, count and accumulate the number of valid detection points in each grid falling into the statistical area for each frame, and obtain the heat map matrices A and B. The heat map matrices A and B need to be initialized as matrices with a size of K×L and all element values being 0 before starting the statistics. When counting each frame, for the k-th grid under the first coordinate dimension and the l-th grid under the second coordinate dimension, if the number of valid detection points falling into the corresponding grid in the current frame under the reference mode and the mode to be corrected are h 1 and h 2 , then increase the value of A k,l by h 1 , and increase the value of B k,l by h 2 ;

[0018] The sum of the multi-frame cumulative results of the number of valid detection points in all grids falling within the statistical region in the reference mode and the mode to be corrected is respectively compared with a preset minimum threshold N min and a maximum threshold N max for comparison, and based on the comparison results, the azimuth angle deviation θ bias of the mode to be corrected relative to the reference mode is calculated or updated.

[0019] Furthermore, based on the comparison results, the azimuth angle deviation θ bias of the mode to be corrected relative to the reference mode is calculated or updated,

[0020] specifically including: min If the sum of the multi-frame accumulation results of the number of valid detection points in all grids falling within the statistical region in any one of the modes is less than N bias , then the azimuth angle deviation θ bias of the mode to be corrected relative to the reference mode is not estimated,

[0021] and at this time θ bias = 0.

[0022] Furthermore, based on the comparison results, the azimuth angle deviation θ min of the mode to be corrected relative to the reference mode is calculated or updated, max specifically including: bias If the sum of the multi-frame cumulative results of the number of valid detection points in all grids falling within the statistical region in each mode is not less than N

[0023] but less than N

[0024] C i (i = -M, -M + 1,..., -1, 0, 1,..., M - 1, M)

[0025] where M represents the number of grids corresponding to the preset maximum azimuth angle deviation of the mode to be corrected relative to the reference mode, and taking a negative sign for i means offsetting in the direction corresponding to the decreasing azimuth angle, and taking a positive sign for i means offsetting in the direction corresponding to the increasing azimuth angle;

[0026] Respectively, for the 2M + 1 matrices C iThe cross - correlation coefficient between (i = -M, -M + 1,..., -1, 0, 1,..., M - 1, M) and the heat - map matrix A of the reference pattern:

[0027]

[0028] where i = -M, -M + 1,..., -1, 0, 1,..., M - 1, M, l = 1, 2,..., L, k = 1, 2,..., K, L and K respectively represent the number of rows and columns of the grid after the statistical area is equally divided into multiple grids, and finally 2M + 1 cross - correlation coefficients are obtained;

[0029] Find the grid number offset i corresponding to the maximum value from the 2M + 1 cross - correlation coefficients α i , and further calculate and update the azimuth angle offset θ of the pattern to be corrected relative to the reference pattern according to i m : m For the Cartesian coordinate system, bias :

[0030] where Δx represents the horizontal distance spanned by each grid when the horizontal coordinate range of the statistical area is evenly divided into multiple grids;

[0031]

[0032] For the polar coordinate system,

[0033] :

[0034] θ bias = i m ·Δθ

[0035] where Δθ represents the azimuth angle spanned by each grid when the azimuth angle coordinate range of the statistical area is evenly divided into multiple grids.

[0036] Furthermore, calculate or update the azimuth angle deviation θ of the pattern to be corrected relative to the reference pattern based on the comparison result, specifically including: bias :

[0037] If the sum of the multi - frame accumulation results of the number of valid detection points in all grids within the statistical area for any one of the patterns is not less than N max , then use the azimuth angle deviation θ calculated in the last frame before the number of valid detection points in all grids within the statistical area for the corresponding pattern reaches N max as the azimuth angle deviation of the pattern to be corrected relative to the reference pattern, and use θ bias as the azimuth angle deviation of the pattern to be corrected relative to the reference pattern for all frames after the last frame. bias ​

[0038] Further, based on the azimuth angle deviation, correct the azimuth angle of the detection points in the mode to be corrected, specifically including:

[0039] According to the offset θ bias correct the azimuth angles of all detection points in the mode to be corrected; assume that the original angle estimation result of the p-th detection point to be corrected is θ p (p = 1, 2,..., P), then the corrected angle dimension θ c = θ p + θ bias , where P is the number of detection points in the mode to be corrected.

[0040] Further, the method further includes:

[0041] If the radar has P (P > 2) modes, where there is a common detection area between mode 1 and mode 2, a common detection area between mode 2 and mode 3, and so on, and a common detection area between mode P and mode P-1, then first use mode 1 as the reference mode to calculate the azimuth angle deviation θ bias21 of mode 2 relative to mode 1, and then use mode 2 as the reference mode to calculate the azimuth angle deviation θ bias32 of mode 3 relative to mode 2, and so on, until the azimuth angle deviation of mode P relative to mode P-1 is calculated, so as to realize the azimuth angle correction of each mode.

[0042] According to a second aspect, an embodiment provides a millimeter-wave radar multi-mode azimuth angle relative deviation automatic correction system, and the system includes:

[0043] A reference mode determination module, configured to determine a reference mode and a mode to be corrected, and a common detection area of the reference mode and the mode to be corrected;

[0044] A statistics module, configured to determine a statistical area based on the common detection area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid;

[0045] An angle deviation determination module, configured to compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area of the reference mode and the mode to be corrected with a preset threshold, and determine the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result;

[0046] A correction module, configured to correct the azimuth angle of the detection points in the mode to be corrected based on the azimuth angle deviation.

[0047] The present application provides a method and system for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes, which determine a reference mode and a mode to be corrected, as well as a common detection area of the reference mode and the mode to be corrected; determine a statistical area based on the common detection area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid; compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area under the reference mode and the mode to be corrected with a preset threshold, and determine the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result; and correct the azimuth angle of the detection points under the mode to be corrected based on the azimuth angle deviation. The method of the present invention is applicable to a millimeter-wave radar including multiple modes with a common detection area between adjacent modes, so as to achieve the purpose of compensating the relative angle measurement deviation between different modes, thereby improving the continuity of the traces between different modes and effectively improving the overall quality of the tracks. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a flowchart of a method for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present invention;

[0049] Figure 2 It is a schematic diagram of the detection area covered by different modes and the common detection area in the X-Y coordinate system in a method for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present invention;

[0050] Figure 3 It is a schematic diagram of dividing the common detection area into grids in the R-θ coordinate system in a method for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present invention;

[0051] Figure 4 It is a comparison diagram of the traces of different modes in the actual scene before and after azimuth angle correction in a method for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present invention;

[0052] Figure 5 It is a schematic diagram of the logical structure of a system for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0053] The present invention will be further described in detail below in conjunction with the specific embodiments and the accompanying drawings. Similar elements in different embodiments are labeled with related similar reference numerals. In the following embodiments, many detailed descriptions are provided to enable a better understanding of the present application. However, those skilled in the art can easily recognize that some of the features can be omitted in different situations, or can be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification to avoid overwhelming the core part of the present application with excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail, and they can fully understand the related operations based on the descriptions in the specification and the general technical knowledge in the art.

[0054] In addition, the features, operations, or characteristics described in the specification can be combined in any appropriate manner to form various embodiments. At the same time, the steps or actions in the method description can also be reordered or adjusted in a manner obvious to those skilled in the art. Therefore, the various sequences in the specification and the drawings are only for clearly describing a certain embodiment and do not mean that they are the necessary sequences, unless it is stated that a certain sequence must be followed.

[0055] A method for automatically correcting the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by the first embodiment of the present invention will be described in detail below in conjunction with Figure 1 for detailed description.

[0056] In this embodiment, it is assumed that the radar has two modes, and the relative azimuth angle deviation between the two modes is automatically corrected.

[0057] In this embodiment, the different modes refer to the working modes responsible for detecting different distance segments; in addition to the difference in the distance segments, the angle measurement arrays used in different modes are generally different, and the corresponding angle resolution, angle measurement accuracy, etc. can also be different. Because of this, there will be a relative deviation in the angle measurement results between different modes, which needs to be corrected; whether different modes work simultaneously is not restricted. Macroscopically, different modes work simultaneously to achieve simultaneous coverage of all distance segments, but microscopically, it is impossible to achieve absolute "simultaneity". For example, in the same frame, it may be necessary to transmit the signal of mode 1 first and then the signal of mode 2. The two cannot be transmitted simultaneously and can only be transmitted alternately, but the alternating time is at the microsecond level. Therefore, from a macroscopic perspective, the two modes can be understood to work simultaneously.

[0058] As Figure 1 shown, in step S100, a reference mode and a mode to be corrected are determined, as well as the common detection area of the reference mode and the mode to be corrected.

[0059] The above steps specifically include:

[0060] Step S110: Determine the reference mode and the mode to be corrected according to the angle measurement accuracy of different modes. In this example, select the mode with higher angle measurement accuracy as the reference mode, and the other mode is the mode to be corrected.

[0061] Step S120: Determine the common detection area covered by the reference mode and the mode to be corrected. As Figure 2 shown, the detection area covered by Mode 1 and the detection area covered by Mode 2 will overlap, that is, there is a common detection area.

[0062] As Figure 1 shown, in step S200, based on the common detection area, determine the statistical area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid.

[0063] The above steps specifically include:

[0064] First, extract all the detection points in the common detection area and the parameter estimation results of each detection point from the detection results obtained by processing the echo signals of each frame of the reference mode and the mode to be corrected.

[0065] It should be noted that after the radar transmitted signal is reflected by a target (such as a pedestrian or a vehicle) and the echo signal is received by the radar, the radar signal processor will process the echo signal to detect target points such as pedestrians and vehicles, which are called detection points, and will perform parameter estimation on each detection point to obtain information such as the distance, speed, azimuth angle, abscissa, ordinate, and signal-to-noise ratio of each detection point.

[0066] Step S210: Process the echo signals received by each mode of each frame separately. The signal processing methods include, but are not limited to, existing technologies such as range-dimensional FFT (Fast Fourier Transform), Doppler-dimensional FFT, non-coherent integration, cfar (constant false alarm rate) detection, and azimuth-angle-dimensional FFT, to obtain all the target detection points detected by each mode of each frame and the parameter estimation results of each target detection point, including information such as distance, speed, azimuth angle, abscissa, ordinate, and signal-to-noise ratio.

[0067] Step S220: Screen out all the detection points that fall into the common detection area and the parameter estimation results of each detection point, including information such as distance, speed, azimuth angle, abscissa, ordinate, and signal-to-noise ratio, from all the detection points of each mode of each frame.

[0068] After obtaining all the detection points in the common detection area of each frame of the reference pattern and the pattern to be corrected, as well as the parameter estimation results of each detection point, determine the azimuth angle deviation of the pattern to be corrected relative to the reference pattern based on the reference pattern, the pattern to be corrected, the multi-frame detection points in the common area, and the parameter estimation results of each detection point, and perform azimuth angle correction.

[0069] Step S230: Select a statistical area from the common detection area of the reference pattern and the pattern to be corrected. The horizontal coordinate range of the statistical area is X min ~X max and the vertical coordinate range is Y min ~Y max .

[0070] Select a statistical area from the common detection area of the reference pattern and the pattern to be corrected. The statistical area can be the entire common detection area or an area with a high probability of target points in the common detection area.

[0071] Step S240: Divide the statistical area into multiple grids equally. In the Cartesian rectangular coordinate system formed with the radar as the origin, divide the horizontal coordinate range and the vertical coordinate range of the statistical area into K and L grids respectively in two dimensions. Among them, the horizontal length of each grid is X step =(X max -X min ) / K, and the vertical length of each grid is Y step =(Y max -Y min ) / L. Or it is also possible to divide the two dimensions of the radial distance coordinate range and the azimuth angle coordinate range of the statistical area into K and L grids respectively in the polar coordinate system formed with the radar as the origin. Fig. Figure 3 is a schematic diagram of dividing the grid for the common detection area in the R-θ coordinate system formed with the radar origin. The azimuth angle coordinate range of the statistical area is θ min ~θ max , and the radial distance coordinate range is R min ~R max .

[0072] Step S250: Screen the detection points with a signal-to-noise ratio greater than the 12 dB threshold and an absolute value of radial velocity greater than 2 m / s that fall within the statistical area in each frame of the reference pattern and the pattern to be corrected as valid detection points.

[0073] As Figure 1 shown, in step S300, compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids within the statistical area in the reference pattern and the pattern to be corrected with a preset threshold, and determine the azimuth angle deviation of the pattern to be corrected relative to the reference pattern according to the comparison result.

[0074] The above steps specifically include:

[0075] Step S310: In the reference mode and the mode to be corrected respectively, count the number of valid detection points in each grid within the statistical region for each frame and accumulate them over multiple frames, and obtain heatmap matrices A and B. The heatmap matrices A and B need to be initialized as matrices of size K×L with all element values being 0 before starting the statistics. When counting each frame, for the k-th grid in the first coordinate dimension and the l-th grid in the second coordinate dimension, if the number of valid detection points falling into the corresponding grid in the current frame in the reference mode and the mode to be corrected are h 1 and h 2 , then increase the value of A k,l by h 1 , and increase the value of B k,l by h 2 .

[0076] Step S320: Compare the sum of the multi-frame cumulative results of the number of valid detection points falling into all grids within the statistical region in the reference mode and the mode to be corrected with the preset minimum threshold N min and the maximum threshold N max (in this implementation, the minimum threshold N min of the multi-frame cumulative number of valid detection points in a single mode should be set large enough, and the maximum threshold N max is determined according to the system processing capacity or the maximum integer limit), and calculate or update the azimuth angle deviation θ bias of the mode to be corrected relative to the reference mode based on the comparison result. Specifically, it is divided into the following three cases:

[0077] (1) If the sum of the multi-frame accumulation results of the number of valid detection points falling into all grids within the statistical region in any one of the modes is less than N min , then do not estimate the azimuth angle deviation θ bias of the mode to be corrected relative to the reference mode. At this time, θ bias = 0.

[0078] (2) If the sum of the multi-frame cumulative results of the number of valid detection points falling into all grids within the statistical region in each mode is not less than N min , but less than N max , then update the azimuth angle deviation θ bias of the mode to be corrected relative to the reference mode according to the heatmap matrices A and B of the reference mode and the mode to be corrected. Specifically, it includes the following steps:

[0079] The heat map matrix B of the pattern to be corrected is sequentially offset by i = -M, -M+1, ..., -1, 0, 1, ..., M-1, M grids along the dimension corresponding to the abscissa range (Cartesian coordinate system) or the azimuth angle coordinate range (polar coordinate system) of the statistical region, to obtain 2M+1 offset matrices:

[0080] C i (i = -M, -M+1, ..., -1, 0, 1, ..., M-1, M)

[0081] where M represents the maximum possible azimuth angle deviation Δθ of the pattern to be corrected relative to the reference pattern max (it is known that the azimuth angle deviation between the two patterns cannot exceed Δθ max ) corresponding number of grids, taking a negative sign for i means offsetting in the direction corresponding to the decreasing azimuth angle, and taking a positive sign for i means offsetting in the direction corresponding to the increasing azimuth angle;

[0082] In this embodiment, in the X-Y coordinate system, M can be determined according to the following formula:

[0083]

[0084] Then, the cross-correlation coefficients of the 2M+1 matrices C i (i = -M, -M+1, ..., -1, 0, 1, ..., M-1, M) after offset of the heat map matrix B of the pattern to be corrected and the heat map matrix A of the reference pattern are respectively calculated:

[0085]

[0086] where i = -M, -M+1, ..., -1, 0, 1, ..., M-1, M, l = 1, 2, ..., L, k = 1, 2, ..., K, and L and K respectively represent the number of rows and columns of the grids after the statistical region is equally divided into multiple grids, and finally 2M+1 cross-correlation coefficients are obtained;

[0087] Find the grid number offset i corresponding to the maximum value from the 2M+1 cross-correlation coefficients α i , and further calculate and update the azimuth angle offset θ of the pattern to be corrected relative to the reference pattern according to i m : m For the Cartesian coordinate system, bias :

[0088] where Δx represents the horizontal distance spanned by each grid when the abscissa range of the statistical region is evenly divided into multiple grids;

[0089]

[0090] where Δx represents the horizontal distance spanned by each grid when the abscissa range of the statistical region is evenly divided into multiple grids;

[0091] For the polar coordinate system,

[0092] θ bias = i m ·Δθ

[0093] where Δθ represents the azimuth angle spanned by each grid when the azimuth angle coordinate range of the statistical region is evenly divided into multiple grids.

[0094] (3) If the sum of the multi-frame accumulation results of the number of valid detection points in all grids within the statistical region for any one of the patterns is not less than N max , then the azimuth angle deviation θ max calculated from the last frame before the number of valid detection points in all grids within the statistical region for the corresponding pattern reaches N bias is used as the azimuth angle deviation of the pattern to be corrected relative to the reference pattern, and θ bias is continuously used as the azimuth angle deviation of the pattern to be corrected relative to the reference pattern for all frames after the last frame, that is, the value of θ bias is not updated at this time.

[0095] As Figure 1 shown, in step S400, based on the azimuth angle deviation, the azimuth angles of the detection points in the pattern to be corrected are corrected.

[0096] Specifically, according to the offset θ bias , the azimuth angles of all detection points in the pattern to be corrected are corrected; assuming that the original angle estimation result of the p-th detection point to be corrected is θ p (p = 1, 2,..., P), then the corrected angle dimension θ c = θ p + θ bias , where P is the number of detection points in the pattern to be corrected.

[0097] App Figure 4 is a comparison diagram of different pattern traces in the actual scene before and after azimuth angle correction using the technical solution of the present invention. App Figure 4 (a) shows the trace diagram without using the technical solution of the present invention for azimuth angle correction. Among them, the black and gray traces respectively represent two patterns responsible for different distance segments. Due to the azimuth angle deviation between the two patterns, it is reflected in the x-y (x represents the horizontal distance, y represents the vertical distance) trace diagram as a relative deviation in the x direction of the traces of the two patterns in the common detection area, as shown in the part marked by the square. After using the technical solution of the present invention for azimuth angle correction, this azimuth deviation is effectively corrected, as shown in App Figure 4 (b) the part marked by the square.

[0098] In another embodiment of the present invention, if the radar has P (P>2) modes, where there is a common detection area between Mode 1 and Mode 2, a common detection area between Mode 2 and Mode 3, and so on, and there is a common detection area between Mode P and Mode P-1, then first take Mode 1 as the reference mode and calculate the azimuth angle deviation θ of Mode 2 relative to Mode 1 bias21 , then take Mode 2 as the reference mode and calculate the azimuth angle deviation θ of Mode 3 relative to Mode 2 bias32 , and so on, until the azimuth angle deviation of Mode P relative to Mode P-1 is calculated, thereby realizing the azimuth angle correction of each mode. The specific steps can refer to the foregoing embodiments and will not be elaborated here

[0099] Corresponding to the automatic correction method for the relative azimuth angle deviation of a millimeter-wave radar in multiple modes disclosed above, an embodiment of the present invention also discloses an automatic correction system for the relative azimuth angle deviation of a millimeter-wave radar in multiple modes, as Figure 5 shown, which specifically includes:

[0100] A reference mode determination module for determining a reference mode and a mode to be corrected, and the common detection area of the reference mode and the mode to be corrected;

[0101] A statistics module for determining a statistical area based on the common detection area, dividing the statistical area into grids, and counting the number of valid detection points of the reference mode and the mode to be corrected in each grid;

[0102] An angle deviation determination module for comparing the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area under the reference mode and the mode to be corrected with a preset threshold, and determining the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result;

[0103] A correction module for correcting the azimuth angle of the detection points under the mode to be corrected based on the azimuth angle deviation.

[0104] It should be noted that for a detailed description of an automatic correction system for the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present invention, reference can be made to the related description of an automatic correction method for the relative azimuth angle deviation of a millimeter-wave radar in multiple modes provided by an embodiment of the present application, which will not be elaborated here.

[0105] The above uses specific examples to elaborate on the present invention, which is only used to help understand the present invention and is not intended to limit the present invention. For those skilled in the technical field to which the present invention belongs, according to the idea of the present invention, several simple deductions, deformations or substitutions can also be made.

Claims

1. A method for automatically correcting relative deviation of multi-mode azimuth angle of millimeter wave radar, characterized in that: The method comprises: Determining a reference pattern and a pattern to be corrected and a common detection area of ​​the reference pattern and the pattern to be corrected; Determine a statistical area based on the common detection area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid; Compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in the reference mode and the mode to be corrected respectively with a preset threshold, and determine the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result; The sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in the reference mode and the mode to be corrected is compared with a preset threshold, and the azimuth angle deviation of the mode to be corrected relative to the reference mode is determined according to the comparison result, specifically including: In the reference mode and the correction mode, the number of valid detection points in each grid in each frame falling into the statistical area is counted and accumulated over multiple frames to obtain the heat map matrices A and B. The heat map matrices A and B need to be initialized to matrices of size K×L with all element values ​​0 before starting the statistics. When each frame is counted, the kth in the first coordinate dimension and the kth in the second coordinate dimension are counted. grids. If the number of valid detection points of the current frame falling into the corresponding grids in the reference mode and the correction mode are and , then The value of , The value of ; The sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in the reference mode and the correction mode is respectively compared with the preset minimum threshold and the maximum threshold Compare and calculate or update the azimuth angle deviation of the mode to be corrected relative to the reference mode based on the comparison result ; Based on the azimuth angle deviation, the azimuth angle of the detection point in the to-be-corrected mode is corrected.

2. A millimeter wave radar multi-mode azimuth angle relative deviation automatic correction method as claimed in claim 1, characterized in that: Determining a reference pattern and a pattern to be corrected and a common detection area of ​​the reference pattern and the pattern to be corrected specifically includes: A mode with relatively high angle measurement accuracy is selected from at least two modes having a common detection area as a reference mode, and a mode with relatively low angle measurement accuracy is selected as a mode to be corrected.

3. The method for automatically correcting relative deviation of multi-mode azimuth angle of millimeter wave radar according to claim 1, characterized in that: Determining a statistical area based on the common detection area, dividing the statistical area into grids, and counting the number of valid detection points of the reference mode and the mode to be corrected in each grid, specifically includes: A statistical area is selected from the common detection area, and the horizontal coordinate range of the statistical area is X min ~X max , the vertical axis range is Y min ~Y max ; In a Cartesian rectangular coordinate system formed with the radar as the origin, the two dimensions of the horizontal coordinate range and the vertical coordinate range of the statistical area are evenly divided into K and L grids respectively, or in a polar coordinate system formed with the radar as the origin, the two dimensions of the radial distance coordinate range and the azimuth angle coordinate range of the statistical area are evenly divided into K and L grids respectively; the dimension divided into K grids is used as the first coordinate dimension, and the dimension divided into L grids is used as the second coordinate dimension; Detection points whose signal-to-noise ratio in each frame falls within the statistical area and is greater than a preset threshold value and whose radial velocity exceeds a preset value are selected as valid detection points.

4. The method for automatically correcting relative deviation of multi-mode azimuth angle of millimeter wave radar according to claim 1, characterized in that: Calculate or update the azimuth angle deviation of the mode to be corrected relative to the reference mode based on the comparison result , specifically including: If the sum of the multi-frame accumulation results of the number of valid detection points in all grids in the statistical area in any of the modes is less than , the azimuth angle deviation of the mode to be corrected relative to the reference mode is not estimated ,at this time .

5. A millimeter wave radar multi-mode azimuth angle relative deviation automatic correction method as claimed in claim 4, characterized in that: Calculate or update the azimuth angle deviation of the mode to be corrected relative to the reference mode based on the comparison result , specifically including: If the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in each mode is not less than , but are smaller than , then the azimuth angle deviation of the mode to be corrected relative to the reference mode is updated according to the thermal map matrices A and B of the reference mode and the mode to be corrected , specifically including: The thermal map matrix B of the mode to be corrected is shifted in sequence along the dimension corresponding to the horizontal coordinate range or the azimuth angle coordinate range of the statistical area. grids, and obtain the offset 2M+1 matrix: Wherein, M represents the number of grids corresponding to the preset maximum azimuth angle deviation of the mode to be corrected relative to the reference mode, i takes a negative sign to indicate a direction deviation corresponding to a decrease in the azimuth angle, and i takes a positive sign to indicate a direction deviation corresponding to an increase in the azimuth angle; Calculate the 2M+1 matrices of the thermal map matrix B of the mode to be corrected after the offset The mutual correlation coefficient with the heat map matrix A of the reference mode: in L and K respectively represent the number of rows and columns of the grids after the statistical area is equally divided into multiple grids, and finally 2M+1 mutual correlation coefficients are obtained; From the 2M+1 correlation coefficient Find the grid number offset i corresponding to the largest value m , according to i m Further calculate and update the azimuth angle offset of the mode to be corrected relative to the reference mode : For the Cartesian coordinate system, in, It means the horizontal distance spanned by each grid when the horizontal coordinate range of the statistical area is evenly divided into multiple grids; For polar coordinates, in, Indicates the azimuth angle spanned by each grid when the azimuth angle coordinate range of the statistical area is evenly divided into multiple grids.

6. A millimeter wave radar multi-mode azimuth angle relative deviation automatic correction method as claimed in claim 5, characterized in that: Calculate or update the azimuth angle deviation of the mode to be corrected relative to the reference mode based on the comparison result , specifically including: If the sum of the multi-frame accumulation results of the number of valid detection points in all grids in the statistical area in any of the modes is not less than , then the number of valid detection points in all grids falling into the statistical area under the corresponding mode reaches The azimuth angle deviation calculated in the last frame before As the azimuth angle deviation of the pattern to be corrected relative to the reference pattern, it is used in all frames after the last frame. As the azimuth angle deviation of the pattern to be corrected relative to the reference pattern.

7. A millimeter wave radar multi-mode azimuth angle relative deviation automatic correction method as claimed in claim 6, characterized in that: Based on the azimuth angle deviation, the azimuth angle of the detection point in the correction mode is corrected, specifically including: According to the offset Correct the azimuth angles of all detection points in the correction mode; assuming that the original angle estimation result of the pth detection point to be corrected is , then the corrected angle dimension ,in is the number of detection points in the calibration mode.

8. The method for automatically correcting relative deviation of multi-mode azimuth angle of millimeter wave radar according to claim 1, characterized in that: The method further comprises: If radar exists There are two modes, among which mode 1 and mode 2 have a common detection area, mode 2 and mode 3 have a common detection area, and so on. Mode P and mode P-1 have a common detection area. Then, mode 1 is used as the reference mode, and the azimuth angle deviation of mode 2 relative to mode 1 is calculated. , and then use mode 2 as the reference mode to calculate the azimuth angle deviation of mode 3 relative to mode 2 , and so on, until the azimuth angle deviation of mode P relative to mode P-1 is calculated, thereby achieving azimuth angle correction for each mode.

9. A millimeter wave radar multi-mode azimuth angle relative deviation automatic correction system, characterized in that: The system comprises: A reference mode determination module, used to determine a reference mode and a mode to be corrected and a common detection area of ​​the reference mode and the mode to be corrected; A statistical module, used to determine a statistical area based on the common detection area, divide the statistical area into grids, and count the number of valid detection points of the reference mode and the mode to be corrected in each grid; An angle deviation determination module, used to compare the sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in the reference mode and the mode to be corrected respectively with a preset threshold, and determine the azimuth angle deviation of the mode to be corrected relative to the reference mode according to the comparison result; The sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in the reference mode and the mode to be corrected is compared with a preset threshold, and the azimuth angle deviation of the mode to be corrected relative to the reference mode is determined according to the comparison result, specifically including: In the reference mode and the correction mode, the number of valid detection points in each grid in each frame falling into the statistical area is counted and accumulated over multiple frames to obtain the heat map matrices A and B. The heat map matrices A and B need to be initialized to matrices of size K×L with all element values ​​0 before starting the statistics. When each frame is counted, the kth in the first coordinate dimension and the kth in the second coordinate dimension are counted. grids. If the number of valid detection points of the current frame falling into the corresponding grids in the reference mode and the correction mode are and , then The value of , The value of ; The sum of the multi-frame cumulative results of the number of valid detection points in all grids in the statistical area in the reference mode and the correction mode is respectively compared with the preset minimum threshold and the maximum threshold Compare and calculate or update the azimuth angle deviation of the mode to be corrected relative to the reference mode based on the comparison result ; The correction module is used to correct the azimuth angle of the detection point in the correction mode based on the azimuth angle deviation.

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