Target angle measurement method and device, radar and storage medium

Abstract

The invention provides a target angle measurement method and device, a radar and a storage medium, and relates to the technical field of detection, and the method comprises the steps: determining a first angle of a target based on first receiving data corresponding to an antenna sub-array in a sparse antenna array; determining a second angle of the target in a first preset angle range based on second receiving data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement precision of the antenna sub-array. According to the invention, the rough angle of the target is determined by using the first receiving data corresponding to the antenna sub-array, and then the accurate angle of the target is determined in the angle range determined based on the rough angle based on the second receiving data corresponding to the whole sparse antenna array, so that only the main lobe and side lobe ratio needs to be increased in a relatively small angle range, and the target angle can be accurately determined. Compared with the improvement of the main lobe and side lobe ratio in the whole angle range of the sparse antenna array, a higher main lobe and side lobe ratio can be obtained, so that the stability of target angle measurement can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of detection, and particularly to a target angle measurement method and device, a radar, and a storage medium. BACKGROUND

[0002] In recent years, sparse array antennas have attracted widespread attention in the fields of wireless communication and radar detection. Sparse array antennas can achieve the advantages of no grating lobe and high angle measurement precision by increasing the spacing between antenna channels and using unequal spacing. However, sparse array antennas also bring the problem of reduced main-to-side lobe ratio.

[0003] In related technologies, the main-to-side lobe ratio of a sparse array antenna is improved by reducing the antenna aperture of the sparse array antenna.

[0004] However, in the above related technologies, the antenna aperture of the sparse array antenna needs to be reduced, and after reducing the antenna aperture, the improvement of the main-to-side lobe ratio of the antenna is not obvious, thereby reducing the stability of target angle measurement. SUMMARY

[0005] The present application provides a target angle measurement method and device, a radar, and a storage medium to solve the defect of reducing the stability of target angle measurement in the prior art.

[0006] The present application provides a target angle measurement method applied to a radar including a sparse antenna array, and the method includes:

[0007] determining a first angle of a target based on first received data corresponding to an antenna subarray in the sparse antenna array;

[0008] determining a second angle of the target within a first preset angle range based on second received data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement precision of the antenna subarray.

[0009] According to the target angle measurement method provided by the present application, the second angle of the target within the first preset angle range is determined based on the second received data corresponding to the sparse antenna array, and includes:

[0010] adding channel data of each antenna channel in the antenna subarray to obtain third received data;

[0011] combining received data corresponding to other antennas in the sparse antenna array except the antenna subarray with the third received data to obtain the second received data corresponding to the sparse antenna array;

[0012] determining a spatial spectrum based on the second received data;

[0013] acquire a first receiving energy corresponding to the first preset angle range in the spatial spectrum;

[0014] determine an angle corresponding to the first receiving energy with the maximum amplitude as the second angle.

[0015] According to the target angle measurement method provided by the application, the method further comprises:

[0016] determine a target aperture of the sparse antenna array based on the angle measurement accuracy of the sparse antenna array;

[0017] determine a target number of antenna placement positions based on the target aperture and the wavelength of the electromagnetic wave;

[0018] determine a first placement position corresponding to the antenna subarray and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions;

[0019] set the antenna subarray based on the first placement position and set the corresponding other antennas based on each of the second placement positions to obtain the sparse antenna array.

[0020] According to the target angle measurement method provided by the application, the determination of the first placement position corresponding to the antenna subarray and the second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions comprises:

[0021] determine a preset number of antenna placement positions from the target number of antenna placement positions, the preset number being determined based on the total number of antenna channels of the sparse antenna array and the number of antenna channels of the antenna subarray;

[0022] determine a randomly selected position in the preset number of antenna placement positions as the first placement position, and determine the other placement positions in the preset number of antenna placement positions except the first placement position as the second placement positions.

[0023] According to the target angle measurement method provided by the application, the determination of the preset number of antenna placement positions from the target number of antenna placement positions comprises:

[0024] Optimize the target number of antenna placement positions to obtain the preset number of antenna placement positions, with the second receiving energy corresponding to a second preset angle range having the maximum mainlobe-to-sidelobe ratio as the target, the second preset angle range being determined based on the angle measurement accuracy of the antenna subarray.

[0025] The target angle measurement method provided by the application comprises the following steps:

[0026] The angle resolution of the sparse antenna array is determined based on the angle measurement accuracy of the sparse antenna array, a preset signal-to-noise ratio and parameters of a window function.

[0027] The target aperture is determined based on the angle resolution and the wavelength of the electromagnetic wave.

[0028] The application further provides a target angle measurement device, comprising:

[0029] A first determination unit is configured to determine a first angle of a target based on first reception data corresponding to a subarray of antennas in a sparse antenna array.

[0030] A second determination unit is configured to determine a second angle of the target within a first preset angle range based on second reception data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement accuracy of the subarray of antennas.

[0031] The application further provides a radar comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement any of the target angle measurement methods described above.

[0032] The application further provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executable on a processor to implement any of the target angle measurement methods described above.

[0033] The application further provides a computer program product comprising a computer program, wherein the computer program is executable on a processor to implement any of the target angle measurement methods described above.

[0034] The target angle measurement method, device, radar and storage medium provided by the application determine a first angle of a target based on first reception data corresponding to a subarray of antennas in a sparse antenna array, and then determine a second angle of the target within a first preset angle range based on second reception data corresponding to the sparse antenna array, wherein the first preset angle range is determined based on the first angle and the angle measurement accuracy of the subarray of antennas. The application first determines a coarse angle of the target based on the first reception data corresponding to the subarray of antennas, and then determines an accurate angle of the target within an angle range determined based on the coarse angle based on the second reception data corresponding to the entire sparse antenna array. Only the main sidelobe ratio needs to be improved within a smaller angle range, and a higher main sidelobe ratio can be obtained compared with improving the main sidelobe ratio within the entire angle range of the sparse antenna array, thereby improving the stability of target angle measurement. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0036] Figure 1 is a spatial spectrum schematic diagram of a radar antenna provided by an embodiment of the present application;

[0037] Figure 2 is one of flow schematic diagrams of a target angle measurement method provided by an embodiment of the present application;

[0038] Figure 3 is another of flow schematic diagrams of a target angle measurement method provided by an embodiment of the present application;

[0039] Figure 4 is a structural schematic diagram of an 8-channel sparse antenna array provided by an embodiment of the present application;

[0040] Figure 5 is a schematic diagram of a beam pattern of a sparse antenna array provided by an embodiment of the present application;

[0041] Figure 6 is a structural schematic diagram of a target angle measurement device provided by an embodiment of the present application;

[0042] Figure 7 is a physical structure schematic diagram of a radar provided by the present application. DETAILED DESCRIPTION

[0043] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely in combination with the drawings in the present application. Obviously, the described embodiments are some embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort belong to the protection scope of the present application.

[0044] Compared with traditional cameras, radars (e.g., millimeter wave radars) for target detection can accurately obtain information such as positions and speeds of road vehicles, radars rely on electromagnetic waves emitted by themselves to detect targets, are not affected by light, and can still work in bad conditions such as rain, snow, and fog, and have a longer detection distance. The antenna aperture is equal to the product of the number of antenna channels and the antenna spacing, and the number of antenna channels of current millimeter wave radars is small, so the antenna aperture is small, the angle measurement accuracy is not high, and the transverse distance measurement of targets is not accurate, which is a key problem hindering the development of millimeter wave radars.

[0045] Traditional millimeter wave radars use uniform array configurations, the antenna spacing is the same, and in order to avoid ambiguity, the antenna spacing cannot exceed half the wavelength of electromagnetic waves. In order to increase the antenna aperture without producing grating lobes, a large-aperture sparse array scheme is proposed: by increasing the antenna spacing and using unequal spacing, both the advantages of no grating lobes and high angle measurement accuracy can be achieved. However, this large-aperture sparse array scheme also brings the problem of reducing the main-to-side lobe ratio.

[0046] When radars are applied in the field of transportation, the signal processing procedure of traditional traffic radars is to first perform range processing and Doppler processing to obtain a range-doppler (RD) map. Constant false alarm rate detection (CFAR) is performed on the RD map, and then the antenna dimension data corresponding to the distance-Doppler unit of the detected target is taken out for angle measurement. Since traffic radars have high range and Doppler resolution, it is generally assumed that there is only one target in a range-Doppler resolution unit, and the method for angle measurement under the single-target assumption is as follows: the received data is subjected to fast Fourier transform (FFT) to obtain a spatial spectrum, and the angle corresponding to the received energy of the maximum amplitude in the spatial spectrum is taken as the target angle. Under this single-target assumption, a low main-to-side lobe ratio will not have too much impact, because the amplitude of the main lobe is always greater than that of the side lobe. However, when multiple targets have similar speeds and similar distances, multiple targets may exist in a range-Doppler unit, which belongs to multi-target angle measurement and will cause the problem of large target side lobe masking small target main lobe. Therefore, under ideal conditions, the large-aperture sparse array scheme is an effective method for traffic radars to solve the contradiction between low angle measurement accuracy and angle measurement ambiguity. It should be noted that, due to the high range and Doppler resolution of traffic radars, this situation generally only exists when multiple vehicles start at the same time from a stationary state, for example, when multiple vehicles start at the same time when the green light is just on.

[0047] In addition, in actual engineering applications, differences in radar antenna production processes can cause poor antenna consistency, and differences in radar board wiring and amplifiers, mixers and other devices of different receiving channels can comprehensively cause phase and amplitude differences between signals received by different receiving antennas, further causing the main-to-side lobe ratio of the radar antenna to be lower than the design value, and in severe cases, even the side lobe is higher than the main lobe, causing the peak position of the target to change from the main lobe to the side lobe when angle measurement is performed, and giving an incorrect angle measurement result. Figure 1 is a spatial spectrum diagram of a radar antenna provided by an embodiment of the present application, as shown in Figure 1 Due to the antenna inconsistency, the amplitude of the main lobe is 62.9599 dB, and the amplitude of the side lobe is 61.5459 dB, thereby causing the main-to-side lobe ratio to decrease.

[0048] In the related art, the main-to-side lobe ratio of a sparse array antenna can be improved by reducing the antenna aperture of the sparse array antenna. Table 1 is the main-to-side lobe ratio of full-angle optimization under different antenna apertures of an 8-channel antenna array, as shown in Table 1, when the antenna aperture is 50 times the half wavelength of an electromagnetic wave, the corresponding main-to-side lobe ratio is 5.02 dB, and when the antenna aperture is 20 times the half wavelength of an electromagnetic wave, the corresponding main-to-side lobe ratio is 7.05 dB. It can be seen that when the antenna aperture is reduced by 40%, the main-to-side lobe ratio is only improved by 2.03 dB, which is not obvious, thereby reducing the stability of target angle measurement.

[0049] Table 1

[0050]

[0051] Based on this, the present application provides a target angle measurement method, which uses the first receiving data corresponding to the antenna subarray in the sparse antenna array to determine the rough angle of the target, and then determines the accurate angle of the target within the angle range determined based on the rough angle based on the second receiving data corresponding to the entire sparse antenna array. Only the main-to-side lobe ratio needs to be improved in a smaller angle range, compared with improving the main-to-side lobe ratio in the entire angle range of the sparse antenna array, a higher main-to-side lobe ratio can be obtained, thereby improving the stability of target angle measurement.

[0052] The target angle measurement method of the present application will be described below. Figures 2-5 The target angle measurement method of the present application can be applied to the field of transportation or other fields that need to detect or track targets.

[0053] Figure 2 is one of the flowcharts of the target angle measurement method provided by an embodiment of the present application, which is applied to a radar including a sparse antenna array, and the radar can be a millimeter wave radar, etc., as shown in Figure 2 The target angle measurement method includes the following steps:

[0054] Step 201, determining a first angle of the target based on first received data corresponding to the antenna subarray in the sparse antenna array.

[0055] The sparse antenna array includes the antenna subarray and other antennas, the antenna subarray includes at least two antenna channels, for example, the number K of the antenna channels can be 2 or 3; one single string antenna can be arranged in each antenna channel, and the spacing between adjacent single string antennas can be half of the wavelength of the electromagnetic wave, and the single string antenna refers to an antenna with a string of oscillators.

[0056] For example, the first received data received by the antenna subarray in the sparse antenna array is obtained, the first received data is subjected to FFT transformation to obtain a spatial spectrum corresponding to the antenna subarray, the spatial spectrum corresponding to the antenna subarray includes received energy corresponding to each angle, and the angle corresponding to the received energy with the largest amplitude is determined as the first angle of the target in all received energies corresponding to the angles. The first angle of the target can be understood as the first angle of the target relative to the radar, and the first angle can be considered as a coarse measurement angle.

[0057] Step 202, determining a second angle of the target in a first preset angle range based on second received data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement accuracy of the antenna subarray.

[0058] The first preset angle range can be The first angle is represented by α, and β = 5-10σ B , σ B The angle measurement accuracy of the antenna subarray can be determined based on the following formula (1) and formula (2):

[0059]

[0060]

[0061] Wherein, k represents a parameter of a window function, which is a value related to the receiving antenna windowing, the value of k ranges from 0.89 to 3, and 1 can be taken during estimation; SNR represents the signal-to-noise ratio after coherent accumulation at the antenna end, and a typical value can be taken according to application requirements; Δθ1 represents the angle resolution of the antenna subarray, λ represents the wavelength of the electromagnetic wave, and D represents the antenna aperture of the antenna subarray, D = K(λ / 2).

[0062] For example, the second received data received by the entire sparse antenna array is obtained, and an FFT transform is performed on the second received data to obtain a spatial spectrum of the sparse antenna array. The abscissa of the spatial spectrum of the sparse antenna array represents the angle, and the ordinate represents the amplitude of the received energy. The received energy with the maximum amplitude is determined among all the received energies within a first preset angle range, and the angle corresponding to the received energy with the maximum amplitude is determined as the second angle of the target, that is, the precise angle of the target.

[0063] The target angle measurement method provided by the present invention determines the first angle of the target based on the first received data corresponding to the antenna subarray in the sparse antenna array, and then detects the second angle of the target within a first preset angle range based on the second received data corresponding to the sparse antenna array, and the first preset angle range is determined based on the first angle and the angle measurement accuracy of the antenna subarray. The present invention uses the first received data corresponding to the antenna subarray to first determine the rough angle of the target, and then determines the precise angle of the target within the angle range determined based on the rough angle based on the second received data corresponding to the entire sparse antenna array. It only needs to improve the main-sidelobe ratio within a smaller angle range. Compared with improving the main-sidelobe ratio within the entire angle range of the sparse antenna array, a higher main-sidelobe ratio can be obtained, thereby improving the stability of the target angle measurement.

[0064] In one embodiment, step 201 determines the first angle of the target based on the first received data corresponding to the antenna subarray in the sparse antenna array, which can be specifically implemented by the following steps:

[0065] In a case where the target is a close-range target, a first angle of the close-range target is determined based on first received data corresponding to the antenna subarray.

[0066] For example, the radar's target detection range can typically reach several hundred meters. For close-range targets, since their distribution angle range is large, the first angle (rough angle) of the close-range target is first determined based on the first received data corresponding to the antenna subarray, and then the precise angle measurement is performed near the rough angle based on the second received data corresponding to the entire sparse antenna array. For long-range targets, since their distribution angle range is very small, usually only a few degrees, to improve angle measurement efficiency, the angle of the long-range target can be measured directly based on the second received data corresponding to the entire sparse antenna array.

[0067] It should be noted that if the angle measurement efficiency and resource waste are not taken into consideration, for distant targets, the first angle (rough angle) of the distant target can be determined based on the first received data corresponding to the antenna subarray, and then the precise angle can be measured near the rough angle based on the second received data corresponding to the entire sparsely distributed antenna array. The present invention does not limit this.

[0068] In the embodiment, when the target is a close-range target, the first angle of the close-range target is determined based on the first received data corresponding to the antenna subarray, and the accurate angle is measured based on the second received data corresponding to the entire sparse antenna array near the first angle, so that the stability of the angle measurement of the close-range target can be improved.

[0069] In an embodiment, the step 202 determines the second angle of the target in the first preset angle range based on the second received data corresponding to the entire sparse antenna array, and the step 202 can be implemented by the following steps:

[0070] The channel data of each antenna channel in the antenna subarray is added to obtain third received data, the received data corresponding to the antennas other than the antennas in the antenna subarray in the entire sparse antenna array is combined with the third received data to obtain the second received data corresponding to the entire sparse antenna array, the spatial spectrum is determined based on the second received data, the first received energy corresponding to the first preset angle range in the spatial spectrum is obtained, and the angle corresponding to the first received energy with the maximum amplitude is determined as the second angle.

[0071] The channel data includes echo data of the target detected by the corresponding antenna.

[0072] For example, the channel data of each antenna channel in the antenna subarray is added to obtain the third received data of the entire sparse antenna array at the position of the antenna subarray, the third received data is combined with the received data of the other antennas in the entire sparse antenna array to obtain the sampling of the entire sparse antenna array at all positions [d1, d2…d N-K+1 ], that is, the second received data of the entire sparse antenna array at all positions is obtained, wherein [d1, d2…d N-K+1 ] represents the positions of the antennas in the entire sparse antenna array, and the positions without antennas in the entire sparse antenna array are supplemented with 0 to obtain an M-dimensional sequence [s1, 0, s2, 0…0, s i …s N-K+1 ], wherein s i represents the channel data of the antenna at the position d i , and the M-dimensional sequence is subjected to FFT transformation to obtain a spatial spectrum, all first received energies in the first preset angle range are selected from the spatial spectrum, the first received energy with the maximum amplitude is determined from all the first received energies, and the angle corresponding to the first received energy with the maximum amplitude is determined as the second angle of the target.

[0073] In the embodiment, the second receiving data of the entire sparse antenna array is determined based on the channel data of each antenna channel in the antenna subarray and the receiving data corresponding to the antennas other than the antenna subarray in the sparse antenna array, the spatial spectrum is determined based on the second receiving data, and the angle corresponding to the first receiving energy with the maximum amplitude in the first preset angle range in the spatial spectrum is determined as the second angle of the target, so that the accurate angle measurement of the target in a smaller angle range is realized, and the stability of the target angle measurement is improved, that is, the robustness of the target angle measurement is improved.

[0074] In an embodiment, Figure 3 FIG. 2 is a flowchart of a target angle measurement method provided by an embodiment of the present application, as shown in the figure, the target angle measurement method comprises the following steps: Figure 3

[0075] Step 301: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array.

[0076] Optionally, the angle resolution of the sparse antenna array is determined based on the angle measurement accuracy of the sparse antenna array, a preset signal-to-noise ratio and parameters of a window function; and the target aperture is determined based on the angle resolution and a wavelength of the electromagnetic wave.

[0077] For example, when designing the sparse antenna array, the angle measurement accuracy of the sparse antenna array can be set first, the angle measurement accuracy of the sparse antenna array is taken as an index value, the angle resolution Δθ2 of the sparse antenna array is determined based on the following formula (3), and the target aperture of the sparse antenna array is determined based on the following formula (4):

[0078]

[0079]

[0080] wherein σ represents the angle measurement accuracy of the sparse antenna array, the angle resolution Δθ2 of the sparse antenna array can be calculated by substituting the angle measurement accuracy σ of the sparse antenna array into the formula (3), and the target aperture D of the sparse antenna array can be calculated by substituting the angle resolution Δθ2 of the sparse antenna array into the formula (4). A .

[0081] Step 302: determining a target number of antenna placement positions based on the target aperture and the wavelength of the electromagnetic wave.

[0082] wherein the distance between two adjacent antenna placement positions is a half wavelength of the electromagnetic wave.

[0083] ​For example, when the target aperture of the sparse antenna array is obtained, the target number of antenna placement positions can be determined based on the target aperture of the sparse antenna array and the wavelength of the electromagnetic wave based on the following formula (5).

[0084] M = [2D A / λ] (5)

[0085] wherein M represents the target number of antenna placement positions, in order to subsequently select N-K+1 antenna placement positions from the M antenna placement positions with a spacing of half the wavelength of the electromagnetic wave to place the sparse antenna array, and other positions do not place antennas, and [] represents rounding up.

[0086] Step 303, determining, from the target number of antenna placement positions, a first placement position corresponding to the antenna subarray and a second placement position corresponding to each of the other antennas in the sparse antenna array.

[0087] Optionally, a preset number of antenna placement positions are determined from the target number of antenna placement positions, a randomly selected position in the preset number of antenna placement positions is determined as the first placement position, and other placement positions in the preset number of antenna placement positions except the first placement position are determined as the second placement positions.

[0088] wherein the preset number is determined based on the total number of antenna channels of the sparse antenna array and the number of antenna channels of the antenna subarray.

[0089] For example, based on the number N of antenna channels of the sparse antenna array and the number K of antenna channels included in the antenna subarray, the number of second placement positions for placing other antennas can be determined as N-K, and since the antenna subarray is equivalent to one antenna, the number of first placement positions for placing the antenna subarray is 1, so the number of placement positions required for placing the antenna subarray and all other antennas is N-K+1, i.e., the preset number is N-K+1, so N-K+1 positions need to be selected from the target number of antenna placement positions to place all antennas of the sparse antenna array, and the N-K+1 positions can be represented as [d1, d2…d N-K+1 ]. Other positions do not place antennas. Specifically, one position can be randomly selected from the N-K+1 positions as the first placement position corresponding to the antenna subarray, and the remaining N-K positions can be used as the second placement positions of the other antennas of the sparse antenna array.

[0090] Step 304, setting the antenna subarray based on the first placement position, and setting each of the other antennas based on the respective second placement positions, to obtain the sparse antenna array.

[0091] For example, when N-K+1 positions are selected from the target number of antenna placement positions, the first placement position is taken as the array center of the antenna subarray, and for K=2, one single-string antenna is arranged on each side of the array center, and the two single-string antennas form an antenna subarray. For N-K second placement positions, one other antenna is arranged at each second placement position, and the other antenna can be a combination of K string antennas. In this way, the antennas arranged at each antenna placement position are the same, and since the antennas arranged in the same way have the same amplitude and phase, the antenna subarray can be used as an ordinary other antenna when performing accurate angle measurement, that is, the sum of the signals received by the antenna subarray is taken as the received signal of a channel of the sparse antenna array, so that the antenna subarray is multiplexed. After the antenna subarray and each other antenna are arranged at the corresponding placement position, the sparse antenna array is obtained. Figure 4 Figure 8 is a structural schematic diagram of an 8-channel sparse antenna array provided by an embodiment of the present application, as shown in the figure, for K=2, an antenna subarray composed of 2 antenna channels and 6 other antenna channels together form an 8-channel sparse antenna array, each antenna channel in the antenna subarray is provided with a single-string antenna, so the antenna arrangement mode of the antenna subarray is a double-string antenna composed of two single-string antennas, and each other antenna channel is provided with a double-string antenna, so the antenna arrangement mode in each other antenna channel is the same as the antenna arrangement mode of the antenna subarray. Figure 4

[0092] It should be noted that when K is even, K / 2 single-string antennas are arranged on each side of the array center, and K single-string antennas form an antenna subarray; when K is odd, one single-string antenna is arranged at the position of the array center, and (K-1) / 2 single-string antennas are arranged on each side of the array center, and K single-string antennas form an antenna subarray.

[0093] In this embodiment, the target aperture of the sparse antenna array is first determined based on the angle measurement accuracy of the sparse antenna array, and then the target number of antenna placement positions is determined based on the target aperture. The first placement position corresponding to the antenna subarray and the second placement position corresponding to each other antenna are determined from the target number of antenna placement positions, and the antenna subarray and each other antenna are arranged at the corresponding placement position to obtain the sparse antenna array, so that the designed sparse antenna array is divided into two parts, one part is the antenna subarray, and the other part is the sparse antenna array composed of the antenna subarray and the other antennas.

[0094] In an embodiment, the above-mentioned determination of a preset number of antenna placement positions from the target number of antenna placement positions can be realized by the following method:

[0095] ​​The target quantity of antenna placement positions is optimized with a maximum mainlobe-to-sidelobe ratio of a second receiving energy corresponding to a second preset angle range as a target, to obtain a preset quantity of antenna placement positions; the second preset angle range is determined based on angle measurement accuracy of the antenna subarray.

[0096] For example, when the target quantity of antenna placement positions is obtained, an optimization algorithm can be used to select the preset quantity of antenna placement positions from the target quantity of antenna placement positions, that is, to select the first placement position and each second placement position, so that the beam pattern of the sparse antenna array designed based on the selected first placement position and each second placement position has a maximum mainlobe-to-sidelobe ratio of a second receiving energy corresponding to a second preset angle range [-β, β]. Figure 5 is a schematic diagram of the beam pattern of the sparse antenna array provided by the embodiment of the application, as shown in Figure 5 It can be seen that the mainlobe-to-sidelobe ratio is relatively high within ±20°. In addition, β = 5-10σ B is to ensure that a larger second preset angle range is obtained, and the coarse angle measurement can be included.

[0097] It should be noted that the aforementioned optimization algorithm can be a genetic algorithm. Specifically, the method for optimizing the target number of antenna placement positions using a genetic algorithm is as follows: 1) Create an initial population, where each individual in the initial population represents an antenna placement configuration. Each individual can be a chromosome containing multiple genes, each gene representing whether a specific antenna placement configuration is selected. A random method or a heuristic strategy can be used to generate the initial population. 2) Define a fitness function to evaluate the performance of each individual (i.e., each antenna placement configuration). The fitness function calculates the mainlobe to sidelobe ratio within a second preset angle range; the larger the mainlobe to sidelobe ratio, the higher the individual's fitness value. The fitness value of each individual is calculated and used as the basis for selection in the genetic algorithm. 3) Perform a selection operation based on the individual fitness values ​​to select outstanding individuals for the next generation. Selection strategies such as roulette wheel selection or tournament selection can be used. 4) Perform a crossover operation on the individuals selected in step 3) to generate new individuals. The crossover operation can simulate the genetic recombination process in nature, generating new genetic combinations by exchanging partial genes from two individuals. 5) Perform a mutation operation on the new individuals generated after the crossover operation in step 4 to increase the diversity of the population. The mutation operation can randomly change a gene of an individual to introduce a new gene combination. 6) Repeat the selection operation, crossover operation, and mutation operation to continuously generate new populations. In each generation, record the individual with the highest fitness value as the optimal solution found so far. Set appropriate termination conditions, such as reaching the maximum number of iterations, or no significant improvement in fitness value over several consecutive generations. When the termination conditions are met, stop iteration and output the individual with the highest fitness value as the optimal antenna placement configuration plan. The optimal antenna placement configuration plan includes the first placement position and each second placement position.

[0098] It should be noted that if Figure 4 As shown, the sparse antenna array is an 8-channel sparse antenna array, wherein the leftmost channel position and the rightmost channel position are the two end positions of the sparse antenna array. Usually, antennas need to be set at both end positions of the sparse antenna array. Therefore, when N-K+1 positions are selected from the target number of antenna placement positions, the positions of the antennas at both ends do not need to be optimized. It is only necessary to use the optimization algorithm to optimize N-K+1-2=NK-1 antenna placement positions.

[0099] In this embodiment, with the goal of having the second received energy corresponding to the second preset angle range have the maximum main-sidelobe ratio, the target number of antenna placement positions are optimized to obtain a preset number of antenna placement positions, so that the sparsely distributed antenna array designed based on the preset number of antenna placement positions has the maximum main-sidelobe ratio within the second preset angle range, thereby improving the stability of the angular measurement of the sparsely distributed antenna array.

[0100] The target angle measurement device provided by the present application is described below, and the target angle measurement device described below can be referred to in correspondence with the target angle measurement method described above.

[0101] Figure 6 FIG. 1 is a structural schematic diagram of a target angle measurement device provided by an embodiment of the present application, as shown in the figure, the target angle measurement device 600 includes a first determination unit 601 and a second determination unit 602; wherein: Figure 6

[0102] The first determination unit 601 is configured to determine a first angle of a target based on first reception data corresponding to an antenna subarray in a sparse antenna array.

[0103] The second determination unit 602 is configured to determine a second angle of the target within a first preset angle range based on second reception data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and an angle measurement accuracy of the antenna subarray.

[0104] The target angle measurement device provided by the present application determines a first angle of a target based on first reception data corresponding to an antenna subarray in a sparse antenna array, and then determines a second angle of the target within a first preset angle range based on second reception data corresponding to the sparse antenna array, and the first preset angle range is determined based on the first angle and an angle measurement accuracy of the antenna subarray. The present application determines a rough angle of a target based on first reception data corresponding to an antenna subarray, and then determines an accurate angle of the target within an angle range determined based on the rough angle based on second reception data corresponding to the entire sparse antenna array. Only a main sidelobe ratio needs to be improved within a smaller angle range, and compared with improving the main sidelobe ratio within the entire angle range of the sparse antenna array, a higher main sidelobe ratio can be obtained, thereby improving the stability of target angle measurement.

[0105] Based on any of the above embodiments, the second determination unit 602 is specifically configured to:

[0106] add channel data of each antenna channel in the antenna subarray to obtain third reception data;

[0107] combine reception data corresponding to other antennas in the sparse antenna array except the antenna subarray with the third reception data to obtain the second reception data corresponding to the sparse antenna array;

[0108] determine a spatial spectrum based on the second reception data;

[0109] obtain a first reception energy corresponding to the first preset angle range in the spatial spectrum;

[0110] ​The angle corresponding to the first received energy with the maximum amplitude is determined as the second angle.

[0111] Based on any of the above embodiments, the target angle measurement device 600 further includes:

[0112] A third determination unit, configured to determine a target aperture of the sparse antenna array based on angle measurement accuracy of the sparse antenna array.

[0113] A fourth determination unit, configured to determine a target number of antenna placement positions based on the target aperture and a wavelength of the electromagnetic wave.

[0114] A fifth determination unit, configured to determine, from the target number of antenna placement positions, a first placement position corresponding to the antenna subarray and second placement positions respectively corresponding to other antennas in the sparse antenna array.

[0115] A setting unit, configured to set the antenna subarray based on the first placement position, and set the other antennas based on the second placement positions respectively, to obtain the sparse antenna array.

[0116] Based on any of the above embodiments, the fifth determination unit is specifically configured to:

[0117] Determine a preset number of antenna placement positions from the target number of antenna placement positions, the preset number being determined based on a total number of antenna channels of the sparse antenna array and a number of antenna channels of the antenna subarray.

[0118] Randomly select a position from the preset number of antenna placement positions as the first placement position, and determine other positions of the preset number of antenna placement positions except the first placement position as the second placement positions.

[0119] Based on any of the above embodiments, the fifth determination unit is further specifically configured to:

[0120] Optimize the target number of antenna placement positions with a second preset angle range corresponding to second received energy having the maximum mainlobe-to-sidelobe ratio as a target, to obtain a preset number of antenna placement positions; the second preset angle range is determined based on angle measurement accuracy of the antenna subarray.

[0121] Based on any of the above embodiments, the third determination unit is specifically configured to:

[0122] Determine angle resolution of the sparse antenna array based on angle measurement accuracy of the sparse antenna array, a preset signal-to-noise ratio, and parameters of a window function.

[0123] Determine the target aperture based on the angle resolution and the wavelength of the electromagnetic wave.

[0124] Figure 7 is a schematic diagram of the physical structure of the radar provided by an embodiment of the present application, as shown, the radar can include: a processor 710, a communications interface 720, a memory 730 and a communications bus 740, wherein the processor 710, the communications interface 720, the memory 730 complete the communication among each other through the communications bus 740. The processor 710 can call the logic instructions in the memory 730 to execute the target angle measurement method applied to the radar including a sparse antenna array, the method comprising: determining a first angle of a target based on first received data corresponding to an antenna subarray in the sparse antenna array; Figure 7

[0125] determining a second angle of the target within a first preset angle range based on second received data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement accuracy of the antenna subarray.

[0126] In addition, the logic instructions in the memory 730 described above can be implemented in the form of a software functional unit and sold or used as an independent product, which can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application or the part of the technical solutions that essentially contribute to the prior art can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the method described in each embodiment of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0127] On the other hand, the present application also provides a computer program product, the computer program product includes a computer program, the computer program can be stored on a computer readable storage medium, when the computer program is executed by a processor, the computer can execute the target angle measurement method provided by the above-mentioned method, which is applied to the radar including a sparse antenna array, the method comprising: determining a first angle of a target based on first received data corresponding to an antenna subarray in the sparse antenna array;

[0128] ​Determine a second angle of the target within a first preset angle range based on the second received data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement accuracy of the antenna subarray.

[0129] In another aspect, the application also provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the target angle measurement method provided by the above method, and is applied to a radar including a sparse antenna array. The method includes: determining a first angle of a target based on first received data corresponding to an antenna subarray in the sparse antenna array;

[0130] Determine a second angle of the target within a first preset angle range based on the second received data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and the angle measurement accuracy of the antenna subarray.

[0131] The device embodiments described above are only schematic, wherein the units shown as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place or distributed on a plurality of network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the embodiment. Those skilled in the art can understand and implement without creative labor.

[0132] From the above description of the embodiments, those skilled in the art can clearly understand that the embodiments can be realized by means of software plus necessary universal hardware platforms, and of course can also be realized by hardware. Based on such understanding, the above technical solutions can be embodied in the form of software product, which can be stored in a computer readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes a plurality of instructions to make a computer device (which can be a personal computer, a server, or a network device, etc.) execute the methods described in each embodiment or some parts of the embodiment.

[0133] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the application, and not to limit them; although the application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements to some technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the application.

Claims

1. A method of target angle measurement, characterized by, The method is applied to a radar comprising a sparse antenna array, and comprises: determining a first angle of a target based on first receiving data corresponding to a subarray of antennas in the sparse antenna array; determining a second angle of the target within a first preset angle range based on second receiving data corresponding to the sparse antenna array; the first preset angle range is determined based on the first angle and an angle measurement accuracy of the subarray of antennas.

2. The target angle measurement method according to claim 1, characterized in that, The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises:

3. The target angle measurement method according to claim 1, characterized by, determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises:

4. The target angle measurement method according to claim 3, characterized by, determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; 5. The target angle measurement method according to claim 4, characterized in that, setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises:

6. The target angle measurement method according to claim 3, wherein determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; 7. A target angle measuring device, characterized by setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method further comprises: determining a target aperture of the sparse antenna array based on an angle measurement accuracy of the sparse antenna array; determining a target number of antenna placement positions based on the target aperture and a wavelength of an electromagnetic wave; determining a first placement position corresponding to the subarray of antennas and a second placement position corresponding to each of the other antennas in the sparse antenna array from the target number of antenna placement positions; setting the subarray of antennas based on the first placement position and setting the other antennas based on the second placement positions, to obtain the sparse antenna array. The method A first determining unit is configured to determine a first angle of a target based on first received data corresponding to a subarray of the sparse antenna array; A second determining unit is configured to determine a second angle of the target within a first preset angle range based on second received data corresponding to the sparse antenna array; The first preset angle range is determined based on the first angle and an angle measurement accuracy of the subarray.

8. A radar comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor implements the target angle measurement method according to any one of claims 1 to 6 when executing the program.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by the processor, implements the target angle measurement method according to any one of claims 1 to 6.

10. A computer program product comprising a computer program, characterized in that, The computer program, when executed by the processor, implements the target angle measurement method according to any one of claims 1 to 6.

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