Antenna correction method and device, driving equipment and readable storage medium

Abstract

The invention discloses an antenna correction method and device, driving equipment and a readable storage medium. The method comprises the following steps: acquiring first echo data received by each receiving channel of a radar system; acquiring target information based on the first echo data; determining an alternative correction matrix from a first correction matrix and at least one second correction matrix based on the target information, the first correction matrix being constructed based on the test data of the first angle range, and the second correction matrix being constructed based on the test data of the corresponding second angle range, the second angle ranges corresponding to the second correction matrixes are different, and the first angle range covers each second angle range; and correcting the first echo data through the alternative correction matrix to obtain second echo data. According to the invention, a mode of combining global correction and partition correction is adopted, and errors of angle measurement results of part of angles in an FOV range can be improved.

Description

Technical Field

[0001] The present application relates to the field of radar antenna technology, and in particular to an antenna calibration method, apparatus, driving equipment, and readable storage medium. Background Art

[0002] Automotive radar systems primarily detect and track targets within their detection range through antenna arrays. The antenna arrays consist of a transmitting antenna array, which transmits electromagnetic wave signals, and a receiving antenna array, which receives echo signals. Due to issues such as coupling between antenna feed lines and phase errors within the RF chip, phase correction of the receiving antenna array is typically required before the radar system is fully operational to improve the accuracy of subsequent radar angle measurement.

[0003] Traditional antenna calibration methods primarily perform phase compensation by acquiring the phase values of targets at different angles within the radar's field of view (FOV) and fitting a sinusoidal curve representing the phase difference of the receiving antenna array and the target angle. However, if the manufacturing errors of the receiving antenna array are large, the fitting results of this method cannot fully represent the relationship between phase difference and angle across the entire radar FOV. Consequently, at certain angles within the FOV (e.g., large angles near the FOV boundary), the angle measurement results may exhibit significant errors. Summary of the Invention

[0004] The embodiments of the present application provide an antenna calibration method, apparatus, driving device, and readable storage medium to improve the situation where the angle measurement results of some angles within the radar FOV range have large errors.

[0005] In order to solve the above technical problems, the embodiments of the present application disclose the following technical solutions:

[0006] In a first aspect, an antenna calibration method is provided, which is applied to a driving device, and the method includes:

[0007] Acquire the first echo data received by each receiving channel of the radar system;

[0008] acquiring target information based on the first echo data;

[0009] Determining, based on the target information, an alternative correction matrix from a first correction matrix and at least one second correction matrix, wherein the first correction matrix is constructed based on test data of a first angle range, and the second correction matrix is constructed based on test data of a corresponding second angle range, each second correction matrix corresponds to a different second angle range, and the first angle range covers each second angle range;

[0010] The first echo data is corrected using the candidate correction matrix to obtain second echo data.

[0011] In a second aspect, an antenna calibration device is provided, configured for a driving device, the device comprising:

[0012] A data acquisition unit, configured to acquire first echo data received by each receiving channel of the radar system;

[0013] a target identification unit, configured to obtain target information based on the first echo data;

[0014] a matrix selection unit, configured to determine, based on the target information, an alternative correction matrix from a first correction matrix and at least one second correction matrix, wherein the first correction matrix is constructed based on test data of a first angle range, and the second correction matrix is constructed based on test data of a corresponding second angle range, each second correction matrix corresponds to a different second angle range, and the first angle range covers each second angle range;

[0015] A phase correction unit is configured to correct the first echo data using the candidate correction matrix to obtain second echo data.

[0016] In a third aspect, an antenna calibration device for a driving device is provided, comprising:

[0017] Memory, used to store programs;

[0018] a processor, configured to execute the program stored in the memory;

[0019] When the program stored in the memory is executed, the processor performs the antenna calibration method as described in any one of the first aspects.

[0020] In a fourth aspect, a driving device is provided, comprising the antenna correction device described in the second aspect.

[0021] In a fifth aspect, a computer-readable storage medium is provided, wherein the computer-readable medium stores instructions for execution by a computing device, and when the computing device executes the instructions, the method as described in any one of the first aspects is implemented.

[0022] One of the above technical solutions has the following advantages or beneficial effects:

[0023] Compared with the prior art, an antenna correction method of the present application includes: obtaining the first echo data received by each receiving channel of the radar system; obtaining target information based on the first echo data; determining an alternative correction matrix from a first correction matrix and at least one second correction matrix based on the target information, the first correction matrix is constructed based on the test data of the first angle range, and the second correction matrix is constructed based on the test data of the corresponding second angle range. The second angle range corresponding to each second correction matrix is different, and the first angle range covers each second angle range; correcting the first echo data through the alternative correction matrix to obtain the second echo data. The antenna correction method provided by the present application adopts a combination of global correction and at least one partition correction, which can significantly improve the situation where the phase correction error of some angles within the FOV range is large, and thereby improve the error of the angle measurement results of these angles.

[0024] An antenna correction device of the present application can significantly improve the situation where the phase correction error of some angles within the FOV range is large, thereby improving the error of the angle measurement results of these angles.

[0025] A driving device of the present application can perform more precise correction on the antenna, thereby achieving better angle measurement accuracy.

[0026] A computer-readable storage medium of the present application can significantly improve the situation where the phase correction error of some angles within the FOV range is large, thereby improving the error of the angle measurement results of these angles. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of a driving scenario for a driving device provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of an antenna array in a radar system provided in an embodiment of the present application;

[0030] Figure 3 This is a schematic diagram of the overall flow of the antenna calibration method according to an embodiment of the present application;

[0031] Figure 4 This is a partial structural diagram of the antenna calibration system in an embodiment of the present application;

[0032] Figure 5a Schematic diagram of the gain direction of each receiving channel azimuth plane before antenna calibration in an embodiment of the present application;

[0033] Figure 5b Schematic diagram of the gain direction of each receiving channel in the azimuth plane after antenna calibration in an embodiment of the present application;

[0034] Figure 6 Schematic diagram of the correlation between the corrected BV data and the target data AZ at different pitch angles in an embodiment of the present application;

[0035] Figure 7 This is a schematic structural diagram of an antenna calibration device according to an embodiment of the present application;

[0036] Figure 8 This is a structural diagram of the antenna correction device of the driving device according to an embodiment of the present application.

[0037] Reference numerals:

[0038] 10-driving equipment; 20-radar system; 21-antenna array; 211-transmitting antenna array; 212-receiving antenna array; 30-antenna correction device; 31-data acquisition unit; 32-target recognition unit; 33-matrix selection unit; 34-phase correction unit; 40-turntable module; 50-target simulator; 60-first processor; 801-memory; 802-second processor. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0040] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, and at least one means one, two or more, unless otherwise clearly and specifically defined.

[0041] See also Figure 1 , Figure 1 The driving scenario of the driving device provided in the embodiment of the present application is illustrated. The driving device 10 is provided with an on-board radar system 20. The radar system 20, such as a millimeter-wave radar, is one of the essential sensors in the advanced driver assistance system of the driving device 10. The radar system 20 can transmit an electromagnetic wave signal S within the FOV range A. When a target P exists within the FOV range A, the electromagnetic wave signal S is reflected by the target P to form an echo signal. After the echo signal is received by the radar system 20, parameters such as the distance, speed, and angle of arrival (AoA) of the target P can be determined based on the echo signal.

[0042] See also Figure 2 , Figure 2 The antenna array in the radar system provided in the embodiment of the present application is illustrated. The radar system 20 mainly detects and tracks targets within the detection range through the antenna array 21. The antenna array 21 includes a transmitting antenna array 211 and a receiving antenna array 212. The transmitting antenna array 211 includes M transmitting antennas TX (Transmits), and the receiving antenna array 212 includes N receiving antennas RX (Receive) with a spacing of d. M is a positive integer greater than or equal to 1, and N is a positive integer greater than or equal to 2. The M transmitting antennas TX and the N receiving antennas RX can form a total of M×N receiving channels. The transmitting antenna array 211 is used to transmit electromagnetic wave signals S, and the receiving antenna array 212 is used to receive echo signals. The arrival angle θ of the target P is mainly calculated by the phase difference between each receiving antenna RX in the receiving antenna array 212. Ideally, the phase difference between each receiving antenna RX is determined by the following formula (1):

[0043] Δω=2πdsin(θ) / λ(1)

[0044] In formula (1), Δω is the phase difference between each receiving antenna RX, d is the distance between any two adjacent receiving antennas RX, θ is the angle of arrival of the target P, and λ is the wavelength. Based on formula (1), it can be seen that when the phase difference Δω between each receiving antenna RX is known, the angle of arrival θ of the target P can be calculated.

[0045] However, due to the influence of factors such as the coupling between the antenna feed lines and the phase error caused by the internal RF chip, as well as the phase error caused by the phase center offset of the antenna array 21, the angle measurement accuracy will be reduced, and the angle measurement accuracy will affect the application performance of the driving assistance system. Therefore, before the radar system 20 is officially used, it is usually necessary to perform phase correction on the receiving antenna array 212 to improve the accuracy of subsequent radar angle measurement. The traditional antenna correction method is to obtain the phase values of targets at different angles within the FOV range, and fit the sin curve of the phase difference of the receiving antenna array 212 and the target angle transformation to perform phase compensation. However, in the case of large processing errors of the receiving antenna array 212, the results fitted by this method cannot represent the relationship between the phase difference and the angle within the entire radar FOV range. At some angles within the FOV range (such as large angles close to the boundary of the FOV range), there will be a situation where the angle measurement result has a large error.

[0046] In view of this, an embodiment of the present application provides a driving device, which, after acquiring the echo data received by the radar system 20, adopts a combination of global correction and at least one partition correction to correct the phase difference between each receiving antenna RX, so as to significantly improve the situation where the phase correction error of some angles within the FOV range is large, and then improve the error of the angle measurement results of these angles, thereby solving at least part of the above-mentioned technical problems.

[0047] Please continue reading Figure 1 The driving device of the embodiment of the present application further includes an antenna correction device 30, which is used to perform phase compensation using the antenna correction method of the embodiment of the present application.

[0048] The antenna calibration method according to an embodiment of the present application is described below with reference to the accompanying drawings.

[0049] See also Figure 3 , Figure 3 The overall process of the antenna calibration method of the embodiment of the present application is illustrated. The antenna calibration method is applied to a driving device and specifically includes the following steps:

[0050] Step 301: Acquire first echo data received by each receiving channel of the radar system.

[0051] Specifically, the first echo data is the BV1 data of each receiving channel, where BV represents beam vector. The first echo data received by each receiving channel can be expressed by the following formula (2):

[0052] BV1=SA+noise(2)

[0053] In formula (2), BV1 is the first echo data received by each receiving channel, S is the signal vector of the original signal amplitude and phase, A is the steering vector of each receiving channel with an amplitude of 1, which represents the phase difference caused by the difference in the path from the target to the receiving channel and is the main basis for phase angle measurement. Noise is noise.

[0054] Step 302: Acquire target information based on the first echo data.

[0055] Specifically, by analyzing the first echo data, the detected target information can be obtained.

[0056] In some examples, the target information may indicate whether the target point is a single target or a dual target, wherein a single target refers to at least one target point with different speeds and / or different distances, and a dual target refers to multiple target points with the same speed and the same distance.

[0057] Step 303: Based on the target information, determine an alternative correction matrix from a first correction matrix and at least one second correction matrix, wherein the first correction matrix is constructed based on the test data of the first angle range, and the second correction matrix is constructed based on the test data of the corresponding second angle range. The second angle range corresponding to each second correction matrix is different, and the first angle range covers each second angle range.

[0058] Specifically, calibration means comparing the measured value with a standard value of known accuracy. The antenna calibration process can be regarded as the process of processing BV to obtain an approximate A. In the radar darkroom, since the target angle of the collected data can be precisely controlled by the turntable, the standard value of known accuracy can be tested and obtained in the microwave darkroom. The darkroom test is mainly carried out by sampling at different angles within the radar FOV. The angle of the collected data is precisely controllable, and the sampled data is used as the standard echo data BV'. Comparing the standard echo data BV' with the first echo data BV1 is the calibration process. This calibration method can compensate for the phase error caused by noise and the phase error caused by feeder coupling and internal processing of the RF chip between antennas. The calibration can be expressed by the following formula (3):

[0059] C×BV1=BV ′ (3)

[0060] In formula (3), C is the correction matrix, which is generated by the darkroom correction test data. BV1 is the first echo data, and BV' is the standard echo data.

[0061] See also Figure 4 , Figure 4The diagram illustrates a partial structure of the antenna correction system in an embodiment of the present application. The antenna correction system includes a turntable module 40, a radar system 20, a target simulator 50, and a first processor 60. The radar system 20 is arranged on the turntable module 40, the first processor 60 is connected to the radar system 20, and the target simulator 50 is used to simulate the target point. During the test process, the antenna correction system is located in a darkroom environment. The turntable module 40 drives the radar system 20 to move at a constant speed with the center of the radar as the rotation axis, so that the target to be measured is located at different detection angles of the radar system 20. When the turntable module 40 rotates to the angle to be measured, the acquisition board in the radar system 20 collects the echo data at the current angle. The turntable module 40 rotates one circle and inputs all the collected echo data as test data to the first processor 60. The first processor 60 runs the phase correction function that has been burned in advance to obtain the correction matrix C of the radar system 20.

[0062] It can be understood that the first correction matrix C1 is constructed based on the test data of the first angle range, and the second correction matrix C2 is constructed based on the test data of the second angle range. The first correction matrix C1 and the second correction matrix C2 are constructed in the same way, except that there is a difference in the target angle corresponding to the test data used.

[0063] In some examples, the first angular range α may be the FOV range of the radar system 20. For example, α satisfies the following: -75° ≤ α ≤ +75°. In other words, the turntable module 40 drives the radar system 20 to rotate from -75° to +75° in a preset step size (e.g., 1°) about the radar center as the rotation axis, thereby collecting test data within the first angular range α. The first correction matrix C1 obtained in this manner may be referred to as a global correction matrix.

[0064] The second angle range β can be any partial angle within the first angle range α. Specifically, the partition that can cover the angle can be selected as the partition corresponding to the second angle range β based on the output angle of the fast Fourier transform (FFT) angle measurement during the experiment. For example, the number of second correction matrices C2 can be two, and the second angle ranges corresponding to the two second correction matrices C2 are β1 and β2, respectively, satisfying: -30°≤β1≤+30°, 10°≤β2≤70°, that is, the turntable module 40 drives the radar system 20 to rotate from -30° to +30° with the radar center as the rotation axis according to a preset step size (e.g., 1°), and collects test data for the second angle range β1. The turntable module 40 drives the radar system 20 to rotate from 10° to 70° with the radar center as the rotation axis according to a preset step size (e.g., 1°), and collects test data for the second angle range β2. The second correction matrix C2 obtained at this time can be called a partition correction matrix.

[0065] For partition correction, if the target angle happens to be within the partition, the partition correction effect will be better than the full FOV correction effect. A good correction effect means a smaller angle error and a lower probability of angle matching errors. However, if the target angle is outside the partition, the correction effect will also be worse. Therefore, how to perform reasonable partitioning so that the target falls within the partition is particularly important. Compared with single-target angle measurement, multi-target angle measurement has higher requirements for partitioning. This is because if the angles of multiple targets are not all within the partition, the probability of angle measurement error will be greatly increased, matching errors will occur, and angle jumps will occur. The correction effect is not as good as the global correction effect. Therefore, when designing partitions, the correctness of multi-target angle matching can be mainly considered to ensure that multiple targets can fall within the correct partition. The specific settings can be made according to actual needs. The embodiment of the present application does not specifically limit the number of second correction matrices C2, each second angle range, and the first angle range.

[0066] In some embodiments, after obtaining corresponding test data, any correction matrix C of the first correction matrix C1 and the second correction matrix C2 is constructed by:

[0067] Step 1: Construct a target expression based on the correction matrix C, the test data X corresponding to the correction matrix, the steering vector A of each receiving channel, and the standard echo data Z.

[0068] Specifically, the target expression is expressed by the following formula (4):

[0069] CX=AZ (4)

[0070] Step 2: Solve the target expression through the Kalman loop to obtain the correction matrix C.

[0071] Specifically, under certain norms, the minimum value of CX-AZ among all possible C and Z is solved, that is, C and Z are solved cyclically so that ‖CX-AZ‖≤ε, where ε is the threshold for stopping the loop.

[0072] Through the above method, the embodiment of the present application can construct a global correction matrix and two partition correction matrices, thereby meeting the requirements of radar angle measurement accuracy and reducing the amount of calculation as much as possible.

[0073] In some embodiments, step 303 may be specifically performed by the following steps:

[0074] Step 1: If the target information indicates that the target point is a single target, the first correction matrix C1 is determined as a candidate correction matrix.

[0075] Step 2: If the target information indicates that the target point is a dual target, the first correction matrix C1 and at least one second correction matrix C2 are determined as candidate correction matrices.

[0076] That is, if the target information indicates that the target point is a single target, the global correction matrix is determined as the alternative correction matrix; if the target information indicates that the target point is a dual target, the global correction matrix and each partition correction matrix are both determined as alternative correction matrices.

[0077] Step 304: Correct the first echo data using the alternative correction matrix to obtain second echo data.

[0078] The second echo data is used to determine the arrival angle of the target point.

[0079] In some embodiments, when the target information indicates that the target point is a single target, step 304 is implemented by the following steps:

[0080] The first echo data BV1 is corrected using the first correction matrix C1 to obtain first corrected data BV1', which is then determined as the second echo data BV2. If the first correction matrix C1 is a global correction matrix, the first angle range is the FOV range of the radar system, and the second echo data BV2 is the global correction result.

[0081] In other embodiments, when the target information indicates that the target point is a dual target, step 304 is implemented by the following steps:

[0082] Step 1: Correct the first echo data BV1 using the first correction matrix C1 to obtain first corrected data BV1 ′.

[0083] Step 2: Correct the first echo data BV1 using the second correction matrices C2 to obtain second corrected data BV2'.

[0084] Step three: based on the correlation between each second corrected data BV2 ′ and the first corrected data BV1 ′, obtain the second echo data BV2 from the first corrected data BV1 ′ and each second corrected data BV2 ′.

[0085] In some examples, step three can be implemented as follows:

[0086] In the first step, the correlation coefficient between each second corrected data BV2 ′ and the first corrected data BV1 ′ is obtained respectively.

[0087] Specifically, the correlation coefficient can be obtained by the following formula (5):

[0088]

[0089] In formula (5), ρ is the correlation coefficient, Cov(BV2′, BV1′) is the covariance between the second corrected data BV2′ and the first corrected data BV1′, D(BV2′) is the variance of the second corrected data BV2′, and D(BV1′) is the variance of the first corrected data BV1′.

[0090] In the second step, if all correlation coefficients are less than or equal to the preset threshold, the first corrected data BV1' is determined as the second echo data BV2. At this time, the second echo data BV2 is the global correction result.

[0091] That is, if the correlation between each second corrected data BV2 ′ and the first corrected data BV1 ′ is low, the global correction result is used as the final correction result.

[0092] In the third step, if there is a correlation coefficient greater than the preset threshold, the second echo data BV2 is obtained from each second correction data BV2' corresponding to the correlation coefficient greater than the preset threshold. At this time, the second echo data BV2 is the partition correction result.

[0093] In some examples, if there is a correlation coefficient greater than a preset threshold, the second correction data BV2' corresponding to the correlation coefficient greater than the preset threshold is determined as the second echo data BV2; if there are multiple correlation coefficients greater than the preset threshold, the maximum correlation coefficient is obtained from the multiple correlation coefficients greater than the preset threshold; the second correction data BV2' corresponding to the maximum correlation coefficient is determined as the second echo data BV2.

[0094] That is, if there are multiple second corrected data BV2 ′ that have a high correlation with the first corrected data BV1 ′, the partition correction result with the highest correlation is used as the final correction result.

[0095] In other examples, if there is a correlation coefficient greater than a preset threshold, the second corrected data BV2' corresponding to the correlation coefficient greater than the preset threshold is determined as the second echo data BV2. If there are multiple correlation coefficients greater than the preset threshold, the target data AZ is constructed based on the standard echo data Z and the steering vector A of each receiving channel. The correlation coefficient between each second corrected data BV2' and the target data AZ is obtained. The second corrected data BV2' corresponding to the largest correlation coefficient is determined as the second echo data BV2. The correlation coefficient between each second corrected data BV2' and the target data AZ can be calculated by referring to the aforementioned formula (5) and will not be repeated here.

[0096] That is, if there are multiple second corrected data BV2 ′ having a high correlation with the first corrected data BV1 ′, the partition correction result having the highest correlation with the target data AZ is used as the final correction result.

[0097] In this way, the method of the embodiment of the present application has significantly improved the problem of excessive angle errors in some cases, while also taking into account the algorithm computing power of the radar, and has a better effect.

[0098] The application effect of the antenna calibration method according to the embodiment of the present application is described below with reference to the accompanying drawings.

[0099] First, the effect of antenna global correction is introduced.

[0100] Please also refer to Figure 5a and Figure 5b , Figure 5a The gain pattern of each receiving channel in the azimuth plane before antenna calibration in the embodiment of the present application is shown. Figure 5b The gain pattern of each receiving channel in the azimuth plane after antenna calibration in the embodiment of the present application is shown. Since the BV1 data for generating the first correction matrix comes from the sampled data at all angles within the radar working FOV, for example, in a darkroom, the turntable module is rotated at intervals of 1° within the horizontal angle range of -75° to +75° to sample the BV data of the target at different horizontal angles, and the gain pattern of the antenna at the horizontal angle is plotted, as shown in FIG. Figure 5a As shown, each curve a is the amplitude of each channel before correction, such as Figure 5b As shown in Figure 2, each curve b is the amplitude of each channel after antenna calibration. By comparison, it can be seen that the BV amplitude consistency of each channel is better after calibration, because calibration essentially removes the initial phase difference and amplitude-phase inconsistency of each receiving channel. Figure 5a and Figure 5b Comparing the antenna gain patterns of each channel before and after correction, it can be seen that the consistency of the patterns is better after correction, indicating that the antenna correction effect is effective.

[0101] See also Figure 6 , Figure 6 The correlation between the corrected BV data and the target data AZ at different pitch angles in the embodiment of the present application is shown. In addition to verifying the global correction effect using the above method, the correlation between the corrected BV data and the target data AZ can also be used to evaluate the effect of the global correction. Figure 6 As shown in the figure, when the elevation angles are -2°, 0°, and 2°, the horizontal angles (Azimuth Angle) with a correlation between BV data and AZ data greater than 0.98 account for about 69.98% of all data, indicating that the global correction effect is good.

[0102] Furthermore, antenna calibration is the starting point for angle measurement. When other conditions remain unchanged, the radar's angle measurement performance can be used to indirectly assess the effectiveness of antenna calibration. Experiments have shown that within the radar's FOV, the horizontal angle measurement error is mostly less than 0.5°, and the elevation angle measurement error is mostly less than 1°, meeting the requirements of radar system design.

[0103] Then the effect of antenna partition correction is introduced.

[0104] The dual-target BV data was synthesized by randomly sampling single-target darkroom data at different pitch and horizontal angles. 10,000 dual-target angle measurement experiments were conducted, and the angle measurement statistics are shown in Table 1.

[0105] Table 1: Statistical results of dual-target angle measurement

[0106] Single Target R2 R1 R0 818 / 10000 6686 / 9182 2065 / 9182 431 / 9182 8.18％ 72.82％ 22.49％ 4.69％

[0107] Among them, "single target" represents the statistical probability of misjudging the angle of two targets as a single target, R2 represents the probability that the angle measurement results of both targets are correct within the allowable range of angle measurement error, R1 represents the probability that only one of the two targets has an accurate angle measurement result, and R0 represents the probability that the angle measurement results of both targets are inaccurate.

[0108] The angle measurement results show that the partition correction method can correctly distinguish the majority of dual-target angles. Looking back at the BV data that was misclassified as a single target, we found that most of the misclassifications were caused by the fact that when the dual-target BV data was randomly generated, the angles of the two targets overlapped or coincided with blurred angles, making them indistinguishable. Leaving aside the "single target" case, the remaining angle measurement errors (R0, R1) can be divided into two cases: one is that the angle match is correct, but the angle deviation is too large (error > angle accuracy); the other is that the angle match is incorrect. This may be due to the two angles being close to blur, that is, the sin value of the two points closest to each other on the sin curve among the two true angles and all blurred angles is less than 0.05.

[0109] At the same time, the FFT angle measurement results affect the selection of candidate partitions. Comparing the differences between the FFT angle measurement results and the true angles of the two targets, the accuracy of FFT angle measurement is shown in Table 2.

[0110] Table 2: Statistics of dual-target angle measurement errors

[0111]

[0112]

[0113] As can be seen from Table 2, the FFT angle measurement has an accuracy rate of over 97%, which is relatively high, indicating that the correction effect of the global FOV correction is good, but it does not fully meet the requirements. In the partition correction, for the matching calculation of two target angles close to fuzzy, there is an increase in the angle error caused by the matching error, which is a disadvantage of the partition correction. Taking into account the disadvantages of the partition correction and the effect of the global FOV correction, the number of partitions can be simplified in the embodiment of the present application, and the partition coverage angle can be increased.

[0114] It can be understood that the antenna correction method of the embodiment of the present application adopts a combination of global correction and at least one partition correction, which can significantly improve the situation where the phase correction error of some angles within the FOV range is large, thereby improving the error of the angle measurement results of this part of the angle, while also taking into account the computing power of the radar algorithm, which is convenient for application.

[0115] Accordingly, see Figure 7 , Figure 7 The antenna calibration device 30 provided in the embodiment of the present application is configured on the driving device 10 and specifically includes a data acquisition unit 31 , a target recognition unit 32 , a matrix selection unit 33 and a phase correction unit 34 .

[0116] The data acquisition unit 31 is used to acquire the first echo data received by each receiving channel of the radar system;

[0117] a target identification unit 32, configured to obtain target information based on the first echo data;

[0118] a matrix selection unit 33 for determining, based on target information, an alternative correction matrix from a first correction matrix and at least one second correction matrix, wherein the first correction matrix is constructed based on test data of a first angle range, and the second correction matrix is constructed based on test data of a corresponding second angle range, each second correction matrix corresponds to a different second angle range, and the first angle range covers each second angle range;

[0119] The phase correction unit 34 is configured to correct the first echo data using an alternative correction matrix to obtain second echo data.

[0120] In some embodiments, the matrix selection unit 33 is specifically configured to:

[0121] If the target information indicates that the target point is a single target, the first correction matrix is determined as the candidate correction matrix;

[0122] If the target information indicates that the target point is a dual target, the first correction matrix and at least one second correction matrix are determined as candidate correction matrices.

[0123] In some embodiments, when the target information indicates that the target point is a dual target, the phase correction unit 34 is specifically configured to:

[0124] Correcting the first echo data using a first correction matrix to obtain first corrected data;

[0125] Correcting the first echo data using respective second correction matrices to obtain respective second correction data;

[0126] Based on the correlation between each second correction data and the first correction data, second echo data are obtained from the first correction data and each second correction data.

[0127] In some embodiments, the phase correction unit 34 is specifically configured to:

[0128] respectively obtaining correlation coefficients of each second correction data with the first correction data;

[0129] If each correlation coefficient is less than or equal to a preset threshold, the first correction data is determined as the second echo data;

[0130] If there is a correlation coefficient greater than the preset threshold, the second echo data is obtained from each second correction data corresponding to the correlation coefficient greater than the preset threshold.

[0131] In some embodiments, the phase correction unit 34 is specifically configured to:

[0132] If there is a correlation coefficient greater than the preset threshold, the second correction data corresponding to the correlation coefficient greater than the preset threshold is determined as the second echo data;

[0133] If there are multiple correlation coefficients greater than the preset threshold, obtaining the maximum correlation coefficient from the multiple correlation coefficients greater than the preset threshold;

[0134] The second corrected data corresponding to the maximum correlation coefficient is determined as the second echo data.

[0135] In some embodiments, the phase correction unit 34 is specifically configured to:

[0136] The correlation coefficient is obtained by the following formula:

[0137]

[0138] Wherein, ρ is the correlation coefficient, Cov(BV2′, BV1′) is the covariance of the second corrected data and the first corrected data, D(BV2′) is the variance of the second corrected data, and D(BV1′) is the variance of the first corrected data.

[0139] In some embodiments, the number of second correction matrices is two, the second angle ranges corresponding to the two second correction matrices are β1 and β2 respectively, the first angle range is α, and the following conditions are satisfied: -75°≤α≤+75°, -30°≤β1≤+30°, 10°≤β2≤70°.

[0140] In some embodiments, either the first correction matrix or the second correction matrix is constructed by:

[0141] Constructing a target expression based on the correction matrix, the test data corresponding to the correction matrix, the steering vectors of each receiving channel, and the standard echo data;

[0142] The target expression is solved by the Kalman cycle to obtain the correction matrix.

[0143] It can be understood that the antenna correction device 30 of the embodiment of the present application can significantly improve the situation where the phase correction error of some angles within the FOV range is large, thereby improving the error of the angle measurement results of these angles.

[0144] Accordingly, see Figure 8 , Figure 8 This figure illustrates the structure of an antenna calibration device for a driving device according to an embodiment of the present application. This embodiment of the present application also provides an antenna calibration device for a driving device, comprising a memory 801 and a second processor 802. Memory 801 is used to store programs. Second processor 802 is used to execute the programs stored in memory 801. When the programs stored in memory 801 are executed, second processor 802 performs the antenna calibration method according to the aforementioned embodiment of the present application.

[0145] Accordingly, the driving device provided in the embodiment of the present application can perform more precise correction on the antenna, thereby achieving better angle measurement accuracy.

[0146] Accordingly, an embodiment of the present application further provides a computer-readable storage medium, which stores instructions for execution by a computing device. When the computing device executes the instructions, the antenna correction method as described in the aforementioned embodiment of the present application is implemented.

[0147] The above is a detailed introduction to an antenna correction method, device, driving equipment and readable storage medium provided in the embodiments of the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the technical solutions and core ideas of the present application; ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some of the technical features therein with equivalents; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. An antenna calibration method, applied to a driving device, characterized in that: The method comprises: Acquire the first echo data received by each receiving channel of the radar system; acquiring target information based on the first echo data; Determining, based on the target information, an alternative correction matrix from a first correction matrix and at least one second correction matrix, wherein the first correction matrix is constructed based on test data of a first angle range, and the second correction matrix is constructed based on test data of a corresponding second angle range, each second correction matrix corresponds to a different second angle range, and the first angle range covers each second angle range; The first echo data is corrected using the candidate correction matrix to obtain second echo data.

2. The antenna calibration method according to claim 1, wherein: Determining an alternative correction matrix from a first correction matrix and at least one of the second correction matrices based on the target information includes: If the target information indicates that the target point is a single target, determining the first correction matrix as the candidate correction matrix; If the target information indicates that the target point is a dual target, the first correction matrix and at least one of the second correction matrices are determined as the candidate correction matrices.

3. The antenna calibration method according to claim 2, wherein: When the target information indicates that the target point is a dual target, correcting the first echo data by using the alternative correction matrix to obtain second echo data includes: Correcting the first echo data using the first correction matrix to obtain first corrected data; Correcting the first echo data using each of the second correction matrices to obtain each of the second corrected data; The second echo data are obtained from the first correction data and each of the second correction data based on the correlation between each of the second correction data and the first correction data.

4. The antenna calibration method according to claim 3, wherein: The acquiring the second echo data from the first corrected data and each of the second corrected data based on the correlation between each of the second corrected data and the first corrected data includes: respectively obtaining a correlation coefficient between each of the second correction data and the first correction data; If each of the correlation coefficients is less than or equal to a preset threshold, determining the first correction data as the second echo data; If there is a correlation coefficient greater than the preset threshold, the second echo data is acquired from each second corrected data corresponding to the correlation coefficient greater than the preset threshold.

5. The antenna calibration method according to claim 4, wherein: The acquiring the second echo data from each piece of the second corrected data corresponding to a correlation coefficient greater than the preset threshold comprises: If there is a correlation coefficient greater than the preset threshold, determining the second corrected data corresponding to the correlation coefficient greater than the preset threshold as the second echo data; If there are multiple correlation coefficients greater than the preset threshold, obtaining the maximum correlation coefficient from the multiple correlation coefficients greater than the preset threshold; The second corrected data corresponding to the maximum correlation coefficient is determined as the second echo data.

6. The antenna calibration method according to claim 4, wherein: The respectively obtaining the correlation coefficient between each second correction data and the first correction data includes: The correlation coefficient is obtained by the following formula: Wherein, ρ is the correlation coefficient, Cov(BV′2, BV′1) is the covariance of the second corrected data and the first corrected data, D(BV′2) is the variance of the second corrected data, and D(BV′1) is the variance of the first corrected data.

7. The antenna calibration method according to any one of claims 1 to 6, characterized in that: The number of the second correction matrices is two, and the second angle ranges corresponding to the two second correction matrices are β1 and β2 respectively. The first angle range is α, satisfying: -75°≤α≤+75°, -30°≤β1≤+30°, 10°≤β2≤70°.

8. The antenna calibration method according to claim 1, wherein: Any correction matrix of the first correction matrix and the second correction matrix is constructed in the following manner: constructing a target expression based on the correction matrix, the test data corresponding to the correction matrix, the steering vectors of each receiving channel, and standard echo data; The target expression is solved by a Kalman cycle to obtain the correction matrix.

9. An antenna calibration device, configured for a driving device, characterized in that: The device comprises: A data acquisition unit, configured to acquire first echo data received by each receiving channel of the radar system; a target identification unit, configured to obtain target information based on the first echo data; a matrix selection unit, configured to determine, based on the target information, an alternative correction matrix from a first correction matrix and at least one second correction matrix, wherein the first correction matrix is constructed based on test data of a first angle range, and the second correction matrix is constructed based on test data of a corresponding second angle range, each second correction matrix corresponds to a different second angle range, and the first angle range covers each second angle range; A phase correction unit is configured to correct the first echo data using the candidate correction matrix to obtain second echo data.

10. An antenna calibration device for a driving device, characterized in that: include: Memory, used to store programs; a processor, configured to execute the program stored in the memory; When the program stored in the memory is executed, the processor performs the antenna calibration method according to any one of claims 1 to 8.

11. A driving device, characterized in that: Including the antenna correction device as described in claim 9.

12. A computer-readable storage medium, characterized in that The computer-readable medium stores instructions for execution by a computing device, and when the computing device executes the instructions, the method according to any one of claims 1 to 8 is implemented.

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