Radar echo data processing method, device, storage medium and terminal equipment

Abstract

The present application proposes a radar echo data processing method, device, storage medium and terminal device, which selects a first preset number of reference points from all target points, wherein the signal-to-noise ratio of any reference point is greater than the signal-to-noise ratio of the non-reference point, and the target point is a point above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data; classifies all non-reference points according to the reference points to determine the target category, wherein the number of target points in the target category is greater than or equal to a second preset number; and outputs the target parameter information of the target points in the target category. By retaining and outputting only the target parameter information of the target points in the target category, the interference data in the target point is screened out, and the accuracy of the output target parameter information is further guaranteed.

Description

Technical Field

[0001] The present application relates to the field of radar, and in particular to a radar echo data processing method, device, storage medium and terminal equipment. Background Art

[0002] Millimeter-wave imaging radars are widely used in various industries, such as the automotive and drone fields. Different from the automotive field's demand for two-dimensional high resolution of millimeter-wave imaging radars, imaging radars in the drone field are mainly used to achieve autonomous obstacle avoidance for drones. For drones working in the agricultural field, radars need to accurately detect targets that need to be avoided, such as trees, overhead wires, and telephone poles, as well as targets that are easy to observe, such as the ground, canals, and dams.

[0003] Because drones need to avoid monitored targets during operation, if false detection occurs, it may affect the operation of the drone and even pose a safety hazard. Therefore, how to improve the detection accuracy of radar has become a difficult problem that needs to be solved by technicians in this field. Summary of the invention

[0004] The purpose of the present application is to provide a radar echo data processing method, apparatus, storage medium and terminal device to at least partially improve the above-mentioned problems.

[0005] In order to achieve the above purpose, the technical solution adopted in the embodiment of the present application is as follows:

[0006] In a first aspect, an embodiment of the present application provides a radar echo data processing method, the method comprising:

[0007] A first preset number of reference points are selected from all target points, wherein the signal-to-noise ratio of any reference point is greater than the signal-to-noise ratio of the non-reference point, and the target point is a point above a one-dimensional distance threshold in a one-dimensional distance spectrum corresponding to the radar echo data;

[0008] Classifying all non-reference points according to the reference points to determine a target category, wherein the number of target points in the target category is greater than or equal to a second preset number;

[0009] Output target parameter information of target points in the target category.

[0010] In a second aspect, an embodiment of the present application provides a radar echo data processing method, the method comprising:

[0011] The points above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data are determined as target points;

[0012] Get the target parameter information corresponding to the target point.

[0013] In a third aspect, an embodiment of the present application provides a radar echo data processing device, the device comprising:

[0014] A processing unit, configured to select a first preset number of reference points from all target points, wherein a signal-to-noise ratio of any reference point is greater than a signal-to-noise ratio of a non-reference point, and the target point is a point above a one-dimensional distance threshold in a one-dimensional range spectrum corresponding to radar echo data;

[0015] The processing unit is further used to classify all non-reference points according to the reference points to determine a target category, wherein the number of target points in the target category is greater than or equal to a second preset number;

[0016] The output unit is used to output target parameter information of the target points in the target category.

[0017] In a fourth aspect, an embodiment of the present application provides a radar echo data processing device, the device comprising:

[0018] The processing unit is used to determine the points above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data as target points; and is also used to obtain target parameter information corresponding to the target points.

[0019] In a fifth aspect, an embodiment of the present application provides a radar device, the radar device comprising M first receiving antenna units, N second receiving antenna units, K transmitting antenna units and a signal processing module, the M first receiving antenna units are arranged in a horizontal direction with a first fixed spacing, the N second receiving antenna units are arranged in a target direction, the angle between the target direction and the horizontal direction is a first preset angle value, the spacing between any two of the second receiving antenna units is the first fixed spacing, at least two of the transmitting antenna units are arranged in the horizontal direction with a second fixed spacing; at least two of the transmitting antenna units are arranged in the target direction with a third fixed spacing, wherein M≥4, N≥2, and K≥3;

[0020] The signal processing module is connected to the first receiving antenna unit, the second receiving antenna unit and the transmitting antenna unit respectively, and is used to process the radar echo data by any of the methods described above.

[0021] In a sixth aspect, an embodiment of the present application provides a movable platform, comprising the above-mentioned radar device.

[0022] In a seventh aspect, an embodiment of the present application provides a storage medium on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0023] In an eighth aspect, an embodiment of the present application provides a terminal device, comprising: a processor and a memory, wherein the memory is used to store one or more programs; when the one or more programs are executed by the processor, the above method is implemented.

[0024] Compared with the prior art, the radar echo data processing method, device, storage medium and terminal device provided in the embodiments of the present application select a first preset number of reference points from all target points, wherein the signal-to-noise ratio of any reference point is greater than the signal-to-noise ratio of the non-reference point, and the target point is a point above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data; classify all non-reference points according to the reference points to determine the target category, wherein the number of target points in the target category is greater than or equal to a second preset number; and output the target parameter information of the target points in the target category. By retaining and outputting only the target parameter information of the target points in the target category, the interference data in the target points is screened out, and the accuracy of the output target parameter information is further guaranteed.

[0025] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 A schematic diagram of the arrangement of antenna units in a radar device provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of the actual aperture of a 3T12R imaging radar corresponding to the antenna array provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of a 3T12R imaging radar virtual aperture array provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of a process flow of a radar echo data processing method provided in an embodiment of the present application;

[0031] Figure 5 A schematic diagram of sub-steps of S109 provided in an embodiment of the present application;

[0032] Figure 6 A schematic diagram of sub-steps of S109-2 provided in an embodiment of the present application;

[0033] Figure 7 One of the flowcharts of the radar echo data processing method provided in the embodiment of the present application;

[0034] Figure 8 One of the flowcharts of the radar echo data processing method provided in the embodiment of the present application;

[0035] Fig. 9 A schematic diagram of sub-steps of S107 provided in an embodiment of the present application;

[0036] Fig.10 A schematic diagram of sub-steps of S107-3 provided in an embodiment of the present application;

[0037] Fig.11 A schematic diagram of sub-steps of S107-7 provided in an embodiment of the present application;

[0038] Fig.12 A schematic diagram of a field test scenario provided for an embodiment of the present application;

[0039] Fig.13 A schematic diagram of the accumulation results of multiple frame point clouds before clustering provided in an embodiment of the present application;

[0040] Fig.14 A schematic diagram of the accumulation results of multi-frame point clouds after clustering provided in an embodiment of the present application;

[0041] FIG. 15( a ) is a top view and a side view of a multi-frame accumulated point cloud before clustering provided by an embodiment of the present application;

[0042] FIG. 15( b ) is a top view and a side view of a multi-frame accumulated point cloud after clustering provided by an embodiment of the present application;

[0043] Fig.16 One of the flowcharts of the radar echo data processing method provided in the embodiment of the present application;

[0044] Fig.17 One of the flowcharts of the radar echo data processing method provided in the embodiment of the present application;

[0045] Fig.18 A schematic diagram of a unit of a radar echo data processing device provided in an embodiment of the present application;

[0046] Fig.19 A schematic diagram of the structure of a terminal device provided in an embodiment of the present application.

[0047] In the figure: 10 - processor; 11 - memory; 12 - bus; 13 - communication interface; 301 - processing unit; 302 - output unit. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings here can be arranged and designed in various different configurations.

[0049] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application for which protection is sought, but merely represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0050] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0051] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0052] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of the application is usually placed when in use. They 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 should not be understood as a limitation on the present application.

[0053] In the description of this application, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] In conjunction with the accompanying drawings, some embodiments of the present application are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0055] At present, most drone-mounted radars are similar to traditional vehicle-mounted radars, with only horizontal resolution. Due to the lack of vertical resolution, some targets below, such as the ground, ditches, and dams, as well as targets above, such as overhead wires, in agricultural scenes, may be mistaken by drones as obstacles on the same horizontal plane in some cases, causing the drones to fly around "non-existent obstacles". 4D imaging radars with vertical resolution are the key to solving the obstacle avoidance problem in this scene.

[0056] 4D imaging radar is a new radar with horizontal and vertical resolution, which is different from traditional vehicle-mounted millimeter-wave radar. 4D imaging radar can achieve two-dimensional target recognition capabilities by virtualizing a two-dimensional receiving antenna array through a certain transceiver antenna array design, and realize four-dimensional (4Dimension) detection of target distance, speed, horizontal angle, and vertical angle. This radar system can provide vertical resolution, which solves the problem that traditional millimeter-wave radars are prone to detecting targets in non-horizontal directions and causing misdetection. 4D imaging radar is used in automobiles, drones and other fields, and helps to realize functions such as three-dimensional obstacle avoidance and road planning.

[0057] The present application embodiment provides a radar device, which can be applied to a mobile platform, and the mobile platform terminal device can be a drone or an unmanned vehicle or other surveying equipment. In a possible implementation, the radar device can be a millimeter wave imaging radar. Please refer to Figure 1The radar device includes M first receiving antenna units, N second receiving antenna units, K transmitting antenna units and a signal processing module, wherein the M first receiving antenna units are arranged in the horizontal direction with a first fixed spacing, and the N second receiving antenna units are arranged in the target direction, and the angle between the target direction and the horizontal direction is a first preset angle value, and the spacing between any two second receiving antenna units is a first fixed spacing, and at least two transmitting antenna units are arranged in the horizontal direction with a second fixed spacing; at least two transmitting antenna units are arranged in the target direction with a third fixed spacing, wherein M≥4, N≥2, and K≥3; and the signal processing module is connected to the first receiving antenna unit, the second receiving antenna unit and the transmitting antenna unit, respectively. Optionally, the signal processing module can execute the radar echo data processing method provided in the implementation of the present application.

[0058] Optionally, the Mth first receiving antenna unit (Rx8) and the N second receiving antenna units (Rx9-Rx12) are arranged along a preset straight line. The K transmitting antenna units transmit in sequence so as to form a virtual aperture array. For ease of presentation, Figure 1 In the example, M is 8, N is 4, and K is 3, but this is not a limitation. The values ​​of M and N can be adjusted according to needs.

[0059] Optionally, the first fixed spacing can be half of the wavelength, and the spacing between the transmitting antenna units is related to the designed virtual array aperture. Optionally, the spacing between Tx1 and Tx2 (the third fixed spacing) is 2.5 wavelengths, and the angle between the line connecting Tx1 and Tx2 (the target direction) and the horizontal direction is about 45°; the spacing between Tx2 and Tx3 (the second fixed spacing) is 4.5 wavelengths, and the line connecting Tx2 and Tx3 is parallel to the horizontal direction. Optionally, Figure 1 The arrangement direction of Rx1~Rx8 is horizontal, and the interval between any two adjacent first receiving antenna units is 0.5 wavelength; the center connection direction of Rx8~Rx12 is parallel to the connection direction of Tx1 and Tx2, and the center point interval between any two adjacent second receiving antenna units is 0.5 wavelength.

[0060] Figure 1 The MIMO radar device shown adopts a time-sharing transmission mode. The radar transmitter controls the transmitting antenna units Tx1, Tx2, and Tx3 to alternately transmit linear frequency modulation waves (FMCW) with a carrier frequency of 24GHz and a bandwidth of 500MHz. At the same time, the receiving antenna units Rx1, Rx2...Rx12 of the radar receiver receive electromagnetic waves in the air. After the electromagnetic wave signal is received, it passes through a low noise amplifier (LNA), a mixer, a power divider, a bandpass filter (BPF), and an analog-to-digital converter (ADC) to obtain an echo signal.

[0061] Figure 2 for Figure 1The actual aperture diagram of the 3T12R imaging radar corresponding to the antenna array shown in the figure. Figure 2 When Tx1, Tx2 and Tx3 are transmitted in sequence, Figure 3 The 3T12R imaging radar virtual aperture array is shown. Figure 3 The 3T12R imaging radar virtual aperture array shown is a cross-shaped or nearly cross-shaped 4D imaging radar, which can achieve high-resolution detection capability of two-dimensional targets with as few transceiver arrays as possible.

[0062] Figure 3 The virtual aperture array in the horizontal direction has a maximum of 16 receiving antenna units, namely Rx13~Rx20, Rx26~Rx32, and a maximum of 10 receiving antenna units in the vertical direction, namely Rx8~Rx12, Rx20~Rx24. The angular resolution in the horizontal and vertical directions can reach up to 7.16° and 11.46°, respectively, achieving a relatively balanced two-dimensional angular resolution capability under a limited receiving array. For a vertically polarized linear array, it is difficult to maintain the vertical spacing at λ / 2 and arrange the receiving antennas vertically, so there is an angle θrx between the vertical receiving antenna and the horizontal direction. Due to the viewing angle problem of the oblique array, the target parameters estimated by the radar equipment need to be mapped to the rectangular coordinate system of the real world through coordinate transformation. The 4D shaping radar can accurately estimate the distance, speed, horizontal angle and vertical angle parameters of a single target. However, for multiple targets at the same distance and speed, their horizontal and vertical angles cannot be matched correspondingly through traditional two-dimensional angle FFT processing, which will lead to missed detection or misdetection of complex scenes or targets with low signal-to-noise ratio, resulting in reduced quality of the output point cloud.

[0063] The radar echo data processing method provided in the embodiment of the present application can be applied to but not limited to Figure 1 For the radar equipment shown, please refer to Figure 4 , radar echo data processing method: S108, S109 and S111.

[0064] S108, selecting a first preset number of reference points from all target points.

[0065] The signal-to-noise ratio of any reference point is greater than that of the non-reference point, and the target point is a point above the one-dimensional distance threshold in the one-dimensional range spectrum corresponding to the radar echo data.

[0066] When the modulus of the target point on the RD signal spectrum is significantly higher than the threshold, the points around it will also be screened out, and the target points with higher signal-to-noise ratio (SNR) have higher estimation accuracy. In one possible implementation, the corresponding signal-to-noise ratios of all target points in the RD domain signal spectrum can be obtained, and the signal-to-noise ratios of all target points are sorted from high to low, and the first preset number of target points in the sorting are used as reference points, and the remaining target points are used as non-reference points. Of course, the signal-to-noise ratios of all target points can also be sorted from low to high.

[0067] The first preset number may be determined in advance according to the total number of target points.

[0068] S109, classifying all non-reference points according to the reference points to determine the target category.

[0069] The number of target points in the target category is greater than or equal to a second preset number.

[0070] In a possible implementation, the target points in the echo data reflected by the target object to be monitored should be concentrated and clustered, that is, the number of target points in the target category is greater than or equal to the second preset number. It can be understood that when the number of target points in a certain category is less than the second preset number, it means that the target points in this category are not the signal data reflected by the target object to be monitored, that is, interference data, and the data in this category does not need to be retained.

[0071] S111, output target parameter information of target points in the target category.

[0072] Optionally, target parameter information of target points in the target category is output according to a preset communication protocol.

[0073] In summary, the embodiment of the present application provides a radar echo data processing method, which selects a first preset number of reference points from all target points, wherein the signal-to-noise ratio of any reference point is greater than the signal-to-noise ratio of the non-reference point, and the target point is a point above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data; classifies all non-reference points according to the reference points to determine the target category, wherein the number of target points in the target category is greater than or equal to a second preset number; and outputs the target parameter information of the target points in the target category. By retaining and outputting only the target parameter information of the target points in the target category, the interference data in the target points is screened out, and the accuracy of the output target parameter information is further guaranteed.

[0074] exist Figure 4 Based on the content in S109, the present application embodiment also provides a possible implementation method, please refer to Figure 5 , S109 includes: S109-1 to S109-4.

[0075] S109-1, for each non-reference point whose category needs to be confirmed, determine whether the non-reference point is of the same category as any reference point. If yes, execute S109-2; if no, execute S109-3.

[0076] Optionally, a non-reference point of a category to be confirmed is determined from all non-reference points that need to be classified. For example, all non-reference points include point A, point B, point C, and point D, and the reference points include point A and point B. Point A may be determined as a non-reference point of a category to be confirmed, and point A may be classified.

[0077] Determine whether point A is of the same category as point A. If point A is of the same category as point A, mark point A as the category corresponding to point A, and execute S109-2. If point A is not of the same category as point A, determine whether point A is of the same category as point B. Repeat the determination until it is determined that the point is of a different category from all reference points, then determine point A as the new reference point, and execute S109-3.

[0078] S109-2, marking the non-reference point as the category corresponding to the reference point.

[0079] S109-3, determine the non-reference point as a new reference point.

[0080] For example, taking point A as a new reference point, points B, C, and D will also be judged as to whether they are of the same type as point A when they are subsequently classified.

[0081] In one possible implementation, after point A is classified, point B, point C, and point D have not yet been classified, and it is necessary to determine new categories of non-reference points to be confirmed from point B, point C, and point D, and repeat the above S109-1 until point B, point C, and point D are all classified. When there are no unclassified non-reference points, determine the target category from all categories, that is, execute S109-4.

[0082] S109-4, determining a category including a number of target points greater than or equal to a second preset number as a target category.

[0083] exist Figure 5 Based on the content in S109-2, how to determine whether the non-reference point with the category to be confirmed is of the same type as any reference point, the embodiment of the present application also provides a possible implementation method, please refer to Figure 6 , S109-1 includes: S109-1A, S109-1B and S109-1C.

[0084] S109-1A, determine whether the non-reference point satisfies the first condition, the second condition, and the third condition.

[0085] Among them, the first condition represents that the absolute value of the distance parameter difference between the non-reference point and the reference point is less than or equal to the preset distance threshold; the second condition represents that the absolute values ​​of all horizontal angle parameter differences between the non-reference point and the reference point are less than or equal to the preset horizontal angle threshold; the third condition represents that the absolute values ​​of all vertical angle parameter differences between the non-reference point and the reference point are less than or equal to the preset vertical angle threshold.

[0086] In a possible implementation, the target parameter information corresponding to the target point includes the distance information, speed information, horizontal angle value and vertical angle value of the target point. The horizontal angle value includes {θ 1 ,θ 2 , ..., θ k}, vertical angle values ​​include {φ 1 ,φ 2 , ..., φ l}.

[0087] θ 1 ,θ 2 ...θ k are the horizontal maximum points g in the horizontal angle pseudo-spectrum 1 , g 2 ... k The corresponding horizontal angle value. are the vertical maximum points h in the vertical angle pseudo-spectrum 1 、h 2 ...h l The corresponding vertical angle value. Optionally, g 1 , g 2 ... k In descending order, h 1 、h 2 ...h l Sort in descending order.

[0088] Consider the following expression:

[0089] {(R, V, θ 1 ,φ 1 ), (R, V, θ 2 ,φ 2 ),…,(R,V,θ min(k，l) ,φ min(k，l) )};

[0090] This expression is the information matrix of the target point, where R represents the distance information of the target point, V represents the speed information of the target point, and min(k,l) represents the minimum value of k and l.

[0091] In a possible implementation, the following distance judgment expression may be used to judge whether the absolute value of the distance parameter difference between the non-reference point of the category to be confirmed and the reference point is less than or equal to the preset distance threshold. The distance judgment expression is as follows:

[0092]

[0093] in, The absolute value of the distance parameter difference between the i-th non-reference point and the k-th reference point, R i Characterizes the distance information of the i-th non-reference point, Represents the distance information of the kth reference point, R th Characterizes the distance threshold, optionally, R th Set to the distance resolution r n times, indicating that adjacent points or points with a distance resolution of D are marked as the same class, r n ≥1.

[0094] In a possible implementation, the following horizontal angle judgment expression can be used to judge whether the absolute values ​​of all horizontal angle parameter differences between the non-reference point to be confirmed and the reference point are less than or equal to the preset horizontal angle threshold. The horizontal angle judgment expression is as follows:

[0095]

[0096] in, Characterizes the absolute value of the horizontal angle parameter difference between the i-th non-reference point and the k-th reference point, θ i Represents the horizontal angle value of the i-th non-reference point, Represents the horizontal angle value of the kth reference point, θ th Characterizes the horizontal angle threshold, for example, 7.6°. It should be noted that, as shown in the above information matrix:

[0097] {(R, V, θ 1 ,φ 1 ), (R, V, θ 2 ,φ 2 ),…,(R,V,θ min(k，l) ,φ min(k，l) )};

[0098] It can be seen from this that the number of horizontal angle values ​​of the i-th non-reference point is more than one, and it is necessary to determine whether the absolute value of the horizontal angle parameter difference between each horizontal angle value of the i-th non-reference point and the horizontal angle value of the k-th reference point is less than or equal to the preset horizontal angle threshold. If the absolute values ​​of all the horizontal angle parameter differences are less than or equal to the preset horizontal angle threshold, it is necessary to further confirm whether the non-reference point is of the same type as the reference point and determine whether the non-reference point meets the third condition; conversely, when the absolute value of the horizontal angle parameter difference between one of the horizontal angle values ​​of the i-th non-reference point and the horizontal angle value of the k-th reference point is greater than the preset horizontal angle threshold, it is determined that the non-reference point whose category is to be confirmed is not of the same category as the reference point.

[0099] In a possible implementation, the following vertical angle judgment expression can be used to judge whether the absolute values ​​of all vertical angle parameter differences between the non-reference point to be confirmed and the reference point are less than or equal to the preset vertical angle threshold. The vertical angle judgment expression is as follows:

[0100]

[0101] in, Characterizes the absolute value of the vertical angle parameter difference between the i-th non-reference point and the k-th reference point, Characterizes the vertical angle value of the i-th non-reference point, Characterizes the vertical angle value of the kth reference point, Characterizes the vertical angle threshold, for example, 11.46°. It should be noted that, as shown in the above information matrix:

[0102] {(R, V, θ 1 ,φ 1 ), (R, V, θ 2 ,φ 2 ), ..., (R, V, θ min(k，l) ,φ min(k，l) )};

[0103] It can be seen from this that the number of vertical angle values ​​of the i-th non-reference point is more than one, and it is necessary to determine whether the absolute value of the vertical angle parameter difference between each vertical angle value of the i-th non-reference point and the vertical angle value of the k-th reference point is less than or equal to the preset vertical angle threshold. If the absolute values ​​of all the vertical angle parameter differences are less than or equal to the preset vertical angle threshold, it is determined that the two are of the same category and S109-1B is executed; conversely, when the absolute value of the vertical angle parameter difference between one of the vertical angle values ​​of the i-th non-reference point and the vertical angle value of the k-th reference point is greater than the preset vertical angle threshold, it is determined that the non-reference point whose category is to be confirmed is not of the same category as the reference point, and S109-1C is executed at this time.

[0104] S109-1B, when the non-reference point satisfies the first condition, the second condition and the third condition, determining that the non-reference point is of the same type as the reference point.

[0105] S109-1C, when the non-reference point does not satisfy any one of the first condition, the second condition and the third condition, determine that the non-reference point is of a different class from the reference point.

[0106] It should be understood that when a non-reference point satisfies the first condition, the second condition and the third condition at the same time, the non-reference point is determined to be of the same type as the reference point; when the non-reference point does not meet any of the first condition, the second condition and the third condition, the non-reference point is determined to be of different types as the reference point.

[0107] In a possible implementation manner, the first item in the information matrix corresponding to the reference point may be used as reference information in the above judgment.

[0108] exist Figure 4 Based on this, regarding the processing of target parameter information of target points in non-target categories, the embodiment of the present application also provides a possible implementation method, such as Figure 7 As shown, after determining the target category, the radar echo data processing method further includes S112.

[0109] S112, discarding the target parameter information of the target point in the non-target category.

[0110] As mentioned above, the target parameter information of the target point in the non-target category is interference data. In order to avoid interference to subsequent calculations and users, this part of the data needs to be discarded.

[0111] In one possible implementation, the original target parameter information is polar coordinate parameters, please continue to refer to Figure 7 In order to facilitate user observation, before S111, the radar echo data processing method also includes S110.

[0112] S110, converting target parameter information of target points in the target category into parameters in a geographic coordinate system.

[0113] Optionally, the horizontal and vertical angles θ of the 3T12R millimeter wave imaging radar are rx =45°, and convert the target parameter information according to the following formula.

[0114]

[0115] y=x tanθ

[0116]

[0117] Among them, x, y and z represent the parameters of the x-axis, y-axis and z-axis in the geographic coordinate system respectively, and θ represents the horizontal angle value of the target point before transformation. Indicates the vertical angle value of the target point before transformation.

[0118] exist Figure 4 On the basis of how to obtain the target point and the corresponding target parameter information, the embodiment of the present application also provides a possible implementation method, please refer to Figure 8 The radar echo data processing method also includes: S101 to S107.

[0119] S101, filtering the radar echo data to remove low-frequency components.

[0120] FMCW radar uses the spectrum of the echo signal to obtain the distance, speed, and angle of the target. Since the ADC can only collect the real signal amplitude and the coupling of the transmitting and receiving antennas, the DC component of the echo signal and the low-frequency component with a frequency close to DC need to be filtered out. In the echo signal preprocessing part, an N-order polynomial fitting method is used to fit a curve according to the echo signal, and the original echo signal is subtracted from the fitted polynomial curve to achieve the goal of removing the low-frequency component. Among them, N is generally not greater than 5.

[0121] S102, performing range Fourier transform and Doppler fast Fourier transform on the radar echo data after the low-frequency components are removed to obtain an RD domain signal spectrum.

[0122] As mentioned above, the radar transmitter controls the transmitting antenna unit to transmit N d Round, each echo signal collects N r Point, the radar receiver receives N r ×N d ×36 echo data. r ×N d ×36 echo data are subjected to range Fourier transform (in the direction of echo collection) and Doppler fast Fourier transform (in the direction of echo accumulation). r ×N d Point echo data as N rf Point and N df The Fourier transform of the point is N. rf ×N df × 36 RD domain signal spectrum. Each point in the RD domain signal spectrum is in complex form, representing the amplitude and phase of the corresponding echo frequency point.

[0123]

[0124] in, Indicates rounding a upwards.

[0125] S103, performing modulus calculation on the RD domain signal spectrum to obtain a modulus value of the RD domain signal spectrum.

[0126] S104, performing incoherent superposition on the modulus values ​​of the RD domain signal spectrum to obtain the RD domain signal spectrum amplitude.

[0127] After taking the modulus value of each point of the RD domain signal spectrum and superimposing it along the receiving channel direction, a sheet of size N is obtained. rf ×N df RD domain signal spectrum amplitude.

[0128] S105, obtaining a one-dimensional distance spectrum according to the RD domain signal spectrum amplitude.

[0129] Optionally, the maximum value of the Doppler dimension (second dimension) is searched in the RD domain signal spectrum amplitude along the distance dimension (first dimension), and the maximum value and its coordinates of the Doppler direction corresponding to each distance unit are recorded. The sequence obtained from the maximum value is a one-dimensional distance spectrum sequence, i.e., a one-dimensional distance spectrum. Its index is used for target velocity estimation and target motion compensation.

[0130] S106: Determine the points in the one-dimensional distance spectrum that are higher than the one-dimensional distance threshold as target points.

[0131] It can be understood that the two dimensions of the RD domain signal spectrum correspond to the frequency changes of the emission time and accumulation time of the echo, and correspond to the distance and speed of the target. When the radar cross-section (RCS) of the target in the radar emission signal is strong enough, the peak at the corresponding position of the distance and speed can be observed in the RD domain signal spectrum amplitude. The maximum value of the Doppler dimension along the distance dimension in the RD signal spectrum amplitude is obtained to obtain a one-dimensional range spectrum. According to the model of radar signal attenuation with distance and the background noise S noise and signal-to-noise ratio parameter P SNR , the one-dimensional distance threshold Th is calculated according to the following formula r , points above the threshold are taken as targets to be detected, i.e., target points.

[0132]

[0133] Among them, K is a model parameter, which is set by the staff.

[0134] S107, obtaining target parameter information corresponding to the target point.

[0135] After the target points are determined to be completed, target parameter information corresponding to each target point is obtained respectively.

[0136] The target parameter information includes horizontal angle value and vertical angle value. Figure 8 Based on the content in S107, the present application embodiment also provides a possible implementation method, please refer to Fig. 9 , S107 includes: S107-1 to S107-10.

[0137] S107-1, obtaining the FFT value of the target point in the RD domain signal spectrum.

[0138] Optionally, get the target point in size N rf ×N df The FFT value in the RD domain signal spectrum of ×36 is used as the input value of two-dimensional angle detection.

[0139] S107-2, arranging the FFT values ​​of the target points in the RD domain signal spectrum to obtain a corresponding virtual aperture array.

[0140] The virtual aperture array is an arrangement and combination of the receiving antenna group relative to different transmitting antennas.

[0141] Optionally, the virtual aperture array is as follows Figure 3 As shown. Among them, Rx1-Rx12 represents the receiving channel corresponding to Tx1 in a round of signals, Rx13-Rx24 represents the receiving channel corresponding to Tx2 in a round of signals, and Rx25-Rx36 represents the receiving channel corresponding to Tx3 in a round of signals. The FFT values ​​of the target points in the RD domain signal spectrum are arranged according to the receiving channels to obtain the corresponding virtual aperture array.

[0142] S107-3, determine the target horizontal array from the virtual aperture array.

[0143] Optionally, the data of Rx13-Rx20 and Rx25-Rx32 are arranged into a vector, which is a target horizontal array.

[0144] S107-4, add a Hanning window to the target horizontal array, and perform N cf Point Fourier transform is performed and then modulo is performed to obtain the horizontal angle pseudo-spectrum.

[0145] Optionally, in the embodiment of the present application, N cf The value of is 32.

[0146] S107-5, selecting horizontal maximum points from the horizontal angle pseudo-spectrum.

[0147] The horizontal maximum point is the point in the horizontal angle pseudo spectrum that is greater than the horizontal angle pseudo spectrum threshold. Continuing with the above example, the horizontal maximum points in the horizontal angle pseudo spectrum include g 1 , g 2 ... k , g 1 , g 2 ... k Arranged in descending order, the index value of the maximum point in the horizontal angle pseudo-spectrum is i1 、i 2 ...i k , g 1 ≥g 2 ≥...≥g k , 0≤k≤N cf Among them, the horizontal angle pseudo-spectrum threshold can be calculated by the following formula:

[0148] S th =(S max -S mean )F th ;

[0149] Among them, S th Characterize the horizontal angle pseudo-spectrum threshold, S max Characterizes the maximum value of the horizontal angle pseudo-spectrum, S mean Characterizes the average value of the horizontal angle pseudo-spectrum, F th Characterizes a preset angle threshold factor. Optionally, the angle threshold factor is set by the staff based on experience.

[0150] S107-6, performing quadratic curve interpolation processing on the horizontal angle pseudo-spectrum according to the index value of the horizontal maximum point, so as to obtain the horizontal angle value of the target point.

[0151] Optionally, quadratic curve interpolation processing is performed on the index value of the horizontal maximum point in the horizontal angle pseudo-spectrum to obtain a horizontal interpolation result, and the horizontal interpolation result is substituted into the horizontal angle formula to obtain the horizontal angle value.

[0152] Optionally, the horizontal angle equation can be expressed as follows:

[0153]

[0154] Among them, θ k Characterize the horizontal maximum point g in the horizontal angle pseudospectrum k The corresponding horizontal angle value, in degrees, i′ k Characterize the horizontal maximum point g k The horizontal interpolation result of the index value of the horizontal angle pseudo spectrum is processed by quadratic curve interpolation. d represents the ratio of the virtual array antenna spacing to the carrier wavelength, and its value is 0.5, 0≤k≤N cf .

[0155] S107-7, determine the target vertical array from the virtual aperture array.

[0156] Optionally, the data of Rx8 to Rx12 and Rx20 to Rx24 are arranged into a vector, which is a target vertical array.

[0157] S107-8, add a Hanning window to the target vertical array, and perform Ncf Point Fourier transform is performed and then modulo is performed to obtain the vertical angle pseudo spectrum.

[0158] S107-9, screening out vertical maximum points from the vertical angle pseudo-spectrum.

[0159] The vertical maximum point is a point in the vertical angle pseudo spectrum that is greater than the vertical angle pseudo spectrum threshold. Continuing with the above example, the vertical maximum points in the vertical angle pseudo spectrum include h 1 、h 2 ...h l ,h 1 、h 2 ...h l Arranged in descending order, the index value of the maximum point in the horizontal angle pseudo-spectrum is j 1 、j 2 ... l ,h 1 ≥h 2 ≥...≥h l , 0≤l≤N cf .

[0160] The process of obtaining the vertical maximum point refers to the process of selecting the horizontal maximum point from the horizontal angle pseudo spectrum in S107-5 above, and will not be described in detail here.

[0161] S107-10, performing quadratic curve interpolation processing on the vertical angle pseudo-spectrum according to the index value of the vertical maximum point, so as to obtain the vertical angle value of the target point.

[0162] Optionally, quadratic curve interpolation processing is performed on the index value of the vertical maximum point on the vertical angle pseudo-spectrum to obtain a vertical interpolation result, and the vertical interpolation result is substituted into the vertical angle formula to obtain the vertical angle value.

[0163] Optionally, the vertical angle equation can be expressed as follows:

[0164]

[0165] in, Characterize the vertical maximum point h in the vertical angle pseudo-spectrum l The corresponding vertical angle value, in degrees, j′ l Characterize the vertical maximum point h l The index value of is the vertical interpolation result of the quadratic curve interpolation processing on the vertical angle pseudo spectrum, d represents the ratio of the virtual array antenna spacing to the carrier wavelength, and the value is 0.5, 0≤l≤N cf .

[0166] After S107-6 and S107-10, the information matrix of the target point can be obtained:

[0167] {(R, V, θ 1 ,φ 1 ), (R, V, θ 2 ,φ 2 ), ..., (R, V, θ min(k，l) ,φ min(k，l) )};

[0168] Among them, R represents the distance information of the target point, V represents the speed information of the target point, and min(k, l) represents the minimum value of k and l.

[0169] exist Fig. 9 Based on the content in S107-3, the present application embodiment also provides a possible implementation method, please refer to Fig.10 , S107-3 includes: S107-3A, S107-3B, S107-3C and S107-3D.

[0170] S107-3A, determine a first horizontal sub-array and a second horizontal sub-array from the virtual aperture array.

[0171] Among them, the first horizontal subarray is an arrangement and combination of the receiving antenna group relative to the first transmitting antenna (TX2), and the second horizontal subarray is an arrangement and combination of the receiving antenna group relative to the second transmitting antenna (TX3). The first transmitting antenna is aligned with the second transmitting antenna in the horizontal direction. In each round of signal transmission, the first transmitting antenna transmits signals first with the second transmitting antenna.

[0172] The first horizontal sub-array is, for example, Figure 3 In Rx8 to Rx12, the second horizontal subarray is, for example, Figure 3 Rx20~Rx24 in.

[0173] S107-3B, determine the horizontal phase compensation factor according to the velocity dimension parameter in the first horizontal subarray.

[0174] Optionally, the target point velocity v is estimated by velocity dimension parameters, and the compensation factor f is obtained according to the following formula.

[0175]

[0176] Wherein, v represents the target point speed, Tp is the transmission time interval, λ is the wavelength, and k is the transmitting antenna unit number. For example, if the number of transmitting antennas is 2, k=1 or 2, and for the second transmitting antenna unit, k-1=1.

[0177] S107-3C, performing phase compensation on the second horizontal subarray according to the horizontal phase compensation factor.

[0178] S107-3D, arranging the first horizontal sub-array and the second horizontal sub-array after phase compensation, so as to obtain a target horizontal array.

[0179] exist Fig. 9 Based on the content in S107-7, the present application embodiment also provides a possible implementation method, please refer to Fig.11 , S107-7 includes: S107-7A, S107-7B, S107-7C and S107-7D.

[0180] S107-7A, determine a first vertical sub-array and a third vertical sub-array from the virtual aperture array.

[0181] Among them, the first vertical subarray is an arrangement and combination of the receiving antenna group relative to the first transmitting antenna (TX2), and the third vertical subarray is an arrangement and combination of the receiving antenna group relative to the third transmitting antenna (TX1). In each round of signal transmission, the third transmitting antenna transmits signals first with the first transmitting antenna.

[0182] Alternatively, the third vertical sub-array may be, for example, Figure 3 In Rx8 to Rx12, the first vertical sub-array is, for example, Figure 3 Rx20~Rx24 in.

[0183] S107-7B, determine the vertical phase compensation factor according to the velocity dimension parameter in the third vertical subarray.

[0184] Optionally, refer to the method for obtaining the horizontal phase compensation factor in S107-3B to obtain the vertical phase compensation factor, which will not be described in detail here.

[0185] S107-7C, performing phase compensation on the first vertical subarray according to the vertical phase compensation factor.

[0186] S107-7D, arranging the third vertical sub-array and the first vertical sub-array after phase compensation, so as to obtain a target vertical array.

[0187] The radar echo data processing method in the embodiment of the present application adopts an intra-frame processing method, which avoids the problem of two-dimensional angle mismatch of the target as much as possible by matching the angle spectrum amplitude. In addition, the clustering method based on the association of neighboring point targets can effectively avoid the influence of random phase disturbances introduced by complex environments, receiver background noise, etc. The radar echo data processing method provided in this embodiment has the following advantages: the angle estimation is pre-sorted according to the intensity of the spectrum, which is convenient for retaining valid target points in subsequent searches and eliminating random noise points; the linear search method is used for clustering, which has higher processing efficiency; field test scenarios such as Fig.12As shown in FIG. 1 , the test scene is a lakeside, and the 24GHz3T12R millimeter wave imaging radar provided in this embodiment is used. The point cloud before clustering and its top view and side view are shown in FIG. Fig.13 As shown in Figure 15(a), the point cloud after clustering is as follows Fig.14 , as shown in Figure 15(b).

[0188] The number of point clouds in a single frame of the test version of the radar is compared by stacking multiple frames. After clustering, the target point cloud is more clustered, and the noise points are less than the target before clustering. The number of point clouds of the target (circled) that does not exist in the lakeside scene in Figure 15(b) is also greatly reduced after processing, which verifies the effectiveness of the radar echo data processing method provided in this embodiment.

[0189] It should be noted that the radar echo data processing method provided in the embodiment of the present application can be applied to meet the two-dimensional angle measurement, and can output radar including distance, speed, horizontal angle, and vertical angle. For the 3T12R array radar illustrated as an example, it has a better effect of reducing the false detection of noise points.

[0190] The present application also provides a radar echo data processing method, please refer to Fig.16 ,like Fig.16 As shown, the radar echo data processing method includes: S206 and S207.

[0191] S206: Determine the points above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data as target points.

[0192] S207, obtaining target parameter information corresponding to the target point.

[0193] exist Fig.16 On this basis, for the content in S207, the embodiment of the present application also provides a possible implementation method, please refer to the following, S207 includes: S207-1 to S207-10.

[0194] S207-1, obtaining the FFT value of the target point in the RD domain signal spectrum.

[0195] Optionally, get the target point in size N rf ×N df The FFT value in the RD domain signal spectrum of ×36 is used as the input value of two-dimensional angle detection.

[0196] S207-2, arranging the FFT values ​​of the target points in the RD domain signal spectrum to obtain a corresponding virtual aperture array.

[0197] The virtual aperture array is an arrangement and combination of the receiving antenna group relative to different transmitting antennas.

[0198] Optionally, the virtual aperture array is as follows Figure 3 As shown. Among them, Rx1-Rx12 represents the receiving channel corresponding to Tx1 in a round of signals, Rx13-Rx24 represents the receiving channel corresponding to Tx2 in a round of signals, and Rx25-Rx36 represents the receiving channel corresponding to Tx3 in a round of signals. The FFT values ​​of the target points in the RD domain signal spectrum are arranged according to the receiving channels to obtain the corresponding virtual aperture array.

[0199] S207-3, determine the target horizontal array from the virtual aperture array.

[0200] Optionally, the data of Rx13-Rx20 and Rx25-Rx32 are arranged into a vector, which is a target horizontal array.

[0201] S207-4, add a Hanning window to the target horizontal array, and perform N cf Point Fourier transform is performed and then modulo is performed to obtain the horizontal angle pseudo-spectrum.

[0202] Optionally, in the embodiment of the present application, N cf The value of is 32.

[0203] S207-5, selecting horizontal maximum points from the horizontal angle pseudo-spectrum.

[0204] The horizontal maximum point is the point in the horizontal angle pseudo spectrum that is greater than the horizontal angle pseudo spectrum threshold. Continuing with the above example, the horizontal maximum points in the horizontal angle pseudo spectrum include g 1 , g 2 ... k , g 1 , g 2 ... k Arranged in descending order, the index value of the maximum point in the horizontal angle pseudo-spectrum is i 1 、i 2 ...i k , g 1 ≥g 2 ≥...≥g k , 0≤k≤N cf .

[0205] S th =(S max -S mean )F th ;

[0206] Among them, S th Characterize the horizontal angle pseudo-spectrum threshold, S max Characterizes the maximum value of the horizontal angle pseudo-spectrum, S mean Characterizes the average value of the horizontal angle pseudo-spectrum, F th Characterizes the preset angle threshold factor.

[0207] S207-6, performing quadratic curve interpolation processing on the horizontal angle pseudo-spectrum according to the index value of the horizontal maximum point, so as to obtain the horizontal angle value of the target point.

[0208] Optionally, quadratic curve interpolation processing is performed on the index value of the horizontal maximum point in the horizontal angle pseudo-spectrum to obtain a horizontal interpolation result, and the horizontal interpolation result is substituted into the horizontal angle formula to obtain the horizontal angle value.

[0209] Optionally, the horizontal angle equation can be expressed as follows:

[0210]

[0211] Among them, θ k Characterize the horizontal maximum point g in the horizontal angle pseudospectrum k The corresponding horizontal angle value, in degrees, i′ k Characterize the horizontal maximum point g k The index value of is the horizontal interpolation result of the quadratic curve interpolation processing on the horizontal angle pseudo spectrum, d represents the ratio of the virtual array antenna spacing to the carrier wavelength, and the value is 0.5, 0≤k≤N cf .

[0212] S207-7, determine the target vertical array from the virtual aperture array.

[0213] Optionally, the data of Rx8 to Rx12 and Rx20 to Rx24 are arranged into a vector, which is a target vertical array.

[0214] S207-8, add a Hanning window to the target vertical array, and perform N cf Point Fourier transform is performed and then modulo is performed to obtain the vertical angle pseudo spectrum.

[0215] S207-9, screening out vertical maximum points from the vertical angle pseudo-spectrum.

[0216] The vertical maximum point is a point in the vertical angle pseudo spectrum that is greater than the vertical angle pseudo spectrum threshold. Continuing with the above example, the vertical maximum points in the vertical angle pseudo spectrum include h 1 、h 2 ...h l ,h 1 、h 2 ...h l Arranged in descending order, the index value of the maximum point in the horizontal angle pseudo-spectrum is j 1 、j 2 ... l ,h 1 ≥h 2 ≥...≥h l , 0≤l≤N cf .

[0217] The process of obtaining the vertical maximum point refers to the process of selecting the horizontal maximum point from the horizontal angle pseudo spectrum in S107-5 above, and will not be described in detail here.

[0218] S207-10, performing quadratic curve interpolation processing on the vertical angle pseudo-spectrum according to the index value of the vertical maximum point, so as to obtain the vertical angle value of the target point.

[0219] Optionally, quadratic curve interpolation processing is performed on the index value of the vertical maximum point in the vertical angle pseudo-spectrum to obtain a vertical interpolation result, and the vertical interpolation result is substituted into the vertical angle formula to obtain the vertical angle value.

[0220] Optionally, the vertical angle equation can be expressed as follows:

[0221]

[0222] in, Characterize the vertical maximum point h in the vertical angle pseudo-spectrum l The corresponding vertical angle value, in degrees, j′ l Characterize the vertical maximum point h l The index value of is the vertical interpolation result of the quadratic curve interpolation processing on the vertical angle pseudo spectrum, d represents the ratio of the virtual array antenna spacing to the carrier wavelength, and the value is 0.5, 0≤l≤N cf .

[0223] After S107-6 and S107-10, the information matrix of the target point can be obtained:

[0224] {(R, V, θ 1 ,φ 1 ), (R, V, θ 2 ,φ 2 ), ..., (R, V, θ min(k，l) ,φ min(k，l) )};

[0225] Among them, R represents the distance information of the target point, V represents the speed information of the target point, and min(k, l) represents the minimum value of k and l.

[0226] On the basis of the above, for the content in S207-3, the embodiment of the present application also provides a possible implementation method, please refer to the following, S207-3 includes: S207-3A, S207-3B, S207-3C and S207-3D.

[0227] S207-3A, determine a first horizontal sub-array and a second horizontal sub-array from the virtual aperture array.

[0228] Among them, the first horizontal subarray is an arrangement and combination of the receiving antenna group relative to the first transmitting antenna (TX2), and the second horizontal subarray is an arrangement and combination of the receiving antenna group relative to the second transmitting antenna (TX3). The first transmitting antenna is aligned with the second transmitting antenna in the horizontal direction. In each round of signal transmission, the first transmitting antenna transmits signals first with the second transmitting antenna.

[0229] The first horizontal sub-array is, for example, Figure 3 In Rx8 to Rx12, the second horizontal subarray is, for example, Figure 3 Rx20~Rx24 in.

[0230] S207-3B, determine a horizontal phase compensation factor according to the velocity dimension parameter in the first horizontal subarray.

[0231] S207-3C, performing phase compensation on the second horizontal subarray according to the horizontal phase compensation factor.

[0232] S207-3D, arranging the first horizontal sub-array and the second horizontal sub-array after phase compensation, so as to obtain a target horizontal array.

[0233] On the basis of the above, for the content in S207-7, the embodiment of the present application also provides a possible implementation method, please refer to the following, S207-7 includes: S207-7A, S207-7B, S207-7C and S207-7D.

[0234] S207-7A, determine a first vertical sub-array and a third vertical sub-array from the virtual aperture array.

[0235] Among them, the first vertical subarray is an arrangement and combination of the receiving antenna group relative to the first transmitting antenna (TX2), and the third vertical subarray is an arrangement and combination of the receiving antenna group relative to the third transmitting antenna (TX1). In each round of signal transmission, the third transmitting antenna transmits signals first with the first transmitting antenna.

[0236] Alternatively, the third vertical sub-array may be, for example, Figure 3 In Rx8 to Rx12, the first vertical sub-array is, for example, Figure 3 Rx20~Rx24 in.

[0237] S207-7B, determine the vertical phase compensation factor according to the velocity dimension parameter in the third vertical subarray.

[0238] S207-7C, performing phase compensation on the first vertical subarray according to the vertical phase compensation factor.

[0239] S207-7D, arranging the third vertical sub-array and the first vertical sub-array after phase compensation, so as to obtain a target vertical array.

[0240] exist Fig.16 Based on how to obtain a one-dimensional distance spectrum, the present application embodiment also provides a possible implementation method, please refer to Fig.17 The radar echo data processing method also includes: S201 to S205.

[0241] S201, filtering the radar echo data to remove low-frequency components.

[0242] FMCW radar uses the spectrum of the echo signal to obtain the distance, speed, and angle of the target. Since the ADC can only collect the real signal amplitude and the coupling of the transmitting and receiving antennas, the DC component of the echo signal and the low-frequency component with a frequency close to DC need to be filtered out. In the echo signal preprocessing part, an N-order polynomial fitting method is used to fit a curve according to the echo signal, and the original echo signal is subtracted from the fitted polynomial curve to achieve the goal of removing the low-frequency component. Among them, N is generally not greater than 5.

[0243] S202, performing range Fourier transform and Doppler fast Fourier transform on the radar echo data after the low-frequency components are removed to obtain an RD domain signal spectrum.

[0244] As mentioned above, the radar transmitter controls the transmitting antenna unit to transmit N d Round, each echo signal collects N r Point, the radar receiver receives N r ×N d ×36 echo data. r ×N d ×36 echo data are subjected to range Fourier transform (in the direction of echo collection) and Doppler fast Fourier transform (in the direction of echo accumulation). r ×N d Point echo data as N rf Point and N df The Fourier transform of the point is N. rf ×N df × 36 RD domain signal spectrum. Each point in the RD domain signal spectrum is in complex form, representing the amplitude and phase of the corresponding echo frequency point.

[0245]

[0246] in, Indicates rounding a upwards.

[0247] S203, performing modulus calculation on the RD domain signal spectrum to obtain a modulus value of the RD domain signal spectrum.

[0248] S204, performing incoherent superposition on the modulus values ​​of the RD domain signal spectrum to obtain the amplitude of the RD domain signal spectrum.

[0249] After taking the modulus value of each point of the RD domain signal spectrum and superimposing it along the receiving channel direction, a sheet of size N is obtained. rf ×N df RD domain signal spectrum amplitude.

[0250] S205, obtaining a one-dimensional distance spectrum according to the RD domain signal spectrum amplitude.

[0251] Optionally, the maximum value of the Doppler dimension (second dimension) is searched in the RD domain signal spectrum amplitude along the distance dimension (first dimension), and the maximum value and its coordinates of the Doppler direction corresponding to each distance unit are recorded. The sequence obtained from the maximum value is a one-dimensional distance spectrum sequence, i.e., a one-dimensional distance spectrum. Its index is used for target velocity estimation and target motion compensation.

[0252] See also Fig.18 , Fig.18 A radar echo data processing device is provided in an embodiment of the present application. Optionally, the radar echo data processing device is applied to the terminal device described above.

[0253] The radar echo data processing device includes: a processing unit 301 and an output unit 302 .

[0254] The processing unit 301 is used to select a first preset number of reference points from all target points, wherein the signal-to-noise ratio of any reference point is greater than the signal-to-noise ratio of the non-reference point, and the target point is a point above the one-dimensional distance threshold in the one-dimensional range spectrum corresponding to the radar echo data.

[0255] The processing unit 301 is further configured to classify all non-reference points according to the reference points to determine a target category, wherein the number of target points in the target category is greater than or equal to a second preset number.

[0256] The output unit 302 is used to output target parameter information of target points in the target category.

[0257] Optionally, the processing unit 301 may execute the above-mentioned S101 - S110 and S112 , and the output unit 302 may execute the above-mentioned S111 .

[0258] In a possible implementation, the processing unit 301 is used to determine points above a one-dimensional distance threshold in a one-dimensional distance spectrum corresponding to the radar echo data as target points; and is also used to obtain target parameter information corresponding to the target points.

[0259] Optionally, the processing unit 301 may execute the above-mentioned S201 - S207 .

[0260] It should be noted that the radar echo data processing device provided in this embodiment can execute the method flow shown in the above method flow embodiment to achieve the corresponding technical effect. For the sake of brief description, for parts not mentioned in this embodiment, reference can be made to the corresponding contents in the above embodiment.

[0261] The embodiment of the present application also provides a storage medium, which stores computer instructions and programs, and when the computer instructions and programs are read and run, the radar echo data processing method of the above embodiment is executed. The storage medium may include a memory, a flash memory, a register, or a combination thereof.

[0262] The following provides a terminal device, which can be a remote controller or other handheld device. The terminal device can communicate with the radar device, and the communication method can be wired communication or wireless communication. Fig.19 As shown, radar equipment is Figure 1 As shown, the two can cooperate to implement the above-mentioned radar echo data processing method. In some embodiments, the radar device can be incorporated into the terminal device so that the terminal device directly carries the radar device; in other embodiments, the radar device and the terminal device can be separately set; specifically, the terminal device includes: a processor 10, a memory 11, and a bus 12. The processor 10 can be a CPU. The memory 11 is used to store one or more programs. When the one or more programs are executed by the processor 10, the radar echo data processing method of the above-mentioned embodiment is executed.

[0263] Optionally, the processor 10 and the memory 11 are connected via a bus 12 , and the processor 10 is used to execute an executable module stored in the memory 11 , such as a computer program.

[0264] The processor 10 may be an integrated circuit chip having signal processing capability. In the implementation process, each step of the radar echo data processing method may be completed by an integrated logic circuit of hardware in the processor 10 or by instructions in the form of software. The above-mentioned processor 10 may be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it may also be a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gates or transistor logic devices, or discrete hardware components.

[0265] The memory 11 may include a high-speed random access memory (RAM), and may also include a non-volatile memory, such as at least one disk memory.

[0266] The bus 12 may be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus. Fig.19 Although only one bidirectional arrow is used in the figure, it does not mean that there is only one bus 12 or only one type of bus 12 .

[0267] The memory 11 is used to store programs, such as programs corresponding to the radar echo data processing device. The radar echo data processing device includes at least one software function module that can be stored in the memory 11 in the form of software or firmware or fixed in the operating system (OS) of the terminal device. After receiving the execution instruction, the processor 10 executes the program to implement the radar echo data processing method.

[0268] Possibly, the terminal device provided in the embodiment of the present application further includes a communication interface 13. The communication interface 13 is connected to the processor 10 via a bus.

[0269] It should be noted that the terminal equipment includes Figure 1 The processor 10 of the radar device can control the radar device and obtain echo data of the radar device.

[0270] It should be understood that Fig.19 The structure shown is only a schematic diagram of a portion of the terminal device. The terminal device may also include Fig.19 More or fewer components as shown, or with Fig.19 Different configurations are shown. Fig.19 Each component shown in the figure can be implemented by hardware, software or a combination thereof.

[0271] In the embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to the multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or the flowchart, and the combination of boxes in the block diagram and / or the flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0272] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0273] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0274] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

[0275] It will be apparent to those skilled in the art that the present application is not limited to the details of the exemplary embodiments described above, and that the present application can be implemented in other specific forms without departing from the spirit or essential features of the present application. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the present application is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present application. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A radar echo data processing method, characterized in that: The method comprises: A first preset number of reference points are selected from all target points, and the remaining target points are used as non-reference points, wherein the signal-to-noise ratio of any reference point is greater than the signal-to-noise ratio of the non-reference point, and the target point is a point above a one-dimensional distance threshold in a one-dimensional range spectrum corresponding to the radar echo data; Classifying all non-reference points according to the reference points to determine a target category, wherein the number of target points in the target category is greater than or equal to a second preset number; Output target parameter information of target points in the target category.

2. The radar echo data processing method according to claim 1, characterized in that: The step of classifying all non-reference points according to the reference points to determine the target category includes: For each non-reference point whose category needs to be confirmed, determining whether the non-reference point is of the same category as any of the reference points; If yes, marking the non-reference point as the category corresponding to the reference point; If not, determining the non-reference point as a new reference point; A category including a number of target points greater than or equal to a second preset number is determined as a target category.

3. The radar echo data processing method according to claim 2, characterized in that: The step of determining whether the non-reference point is of the same type as any of the reference points comprises: Determine whether the non-reference point satisfies the first condition, the second condition and the third condition; wherein the first condition indicates that the absolute value of the distance parameter difference between the non-reference point and the reference point is less than or equal to a preset distance threshold; the second condition indicates that the absolute values ​​of all horizontal angle parameter differences between the non-reference point and the reference point are less than or equal to a preset horizontal angle threshold; the third condition indicates that the absolute values ​​of all vertical angle parameter differences between the non-reference point and the reference point are less than or equal to a preset vertical angle threshold; When the non-reference point satisfies the first condition, the second condition, and the third condition, determining that the non-reference point is of the same type as the reference point; When the non-reference point does not satisfy any one of the first condition, the second condition, and the third condition, it is determined that the non-reference point is of a different class from the reference point.

4. The radar echo data processing method according to claim 1, characterized in that: After classifying all non-reference points according to the reference points to determine the target category, the method further includes: The target parameter information of target points in non-target categories is discarded.

5. The radar echo data processing method according to claim 1, characterized in that: The original target parameter information is polar coordinate parameters. Before outputting the target parameter information of the target point in the target category, the method further includes: Convert the target parameter information of the target point in the target category into parameters under the geographic coordinate system.

6. The radar echo data processing method according to claim 1, characterized in that: Before selecting a first preset number of reference points from all target points, the method further includes: Filter the radar echo data to remove low-frequency components; Perform range Fourier transform and Doppler fast Fourier transform on the radar echo data after removing the low-frequency components to obtain the RD domain signal spectrum; Performing modulus calculation on the RD domain signal spectrum to obtain a modulus value of the RD domain signal spectrum; Perform incoherent superposition on the modulus values ​​of the RD domain signal spectrum to obtain the RD domain signal spectrum amplitude; Obtain one-dimensional distance spectrum according to the RD domain signal spectrum amplitude; The points in the one-dimensional distance spectrum that are higher than the one-dimensional distance threshold are determined as target points; Get the target parameter information corresponding to the target point.

7. The radar echo data processing method according to claim 1, characterized in that: The method comprises: The points above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data are determined as target points; Get the target parameter information corresponding to the target point.

8. The radar echo data processing method according to claim 7, characterized in that: The target parameter information includes a horizontal angle value and a vertical angle value; the step of obtaining the target parameter information corresponding to the target point includes: Obtaining the FFT value of the target point in the RD domain signal spectrum; Arranging the FFT values ​​of the target point in the RD domain signal spectrum to obtain a corresponding virtual aperture array; wherein the virtual aperture array is an arrangement and combination of a receiving antenna group relative to different transmitting antennas; Determine a target horizontal array from the virtual aperture array, add a Hanning window to the target horizontal array, and perform N cf Point Fourier transform is performed, and then modulo is performed to obtain the horizontal angle pseudo-spectrum; Filtering out a horizontal maximum point from the horizontal angle pseudo spectrum, wherein the horizontal maximum point is a point greater than a horizontal angle pseudo spectrum threshold; Performing quadratic curve interpolation processing on the horizontal angle pseudo-spectrum according to the index value of the horizontal maximum point, so as to obtain the horizontal angle value of the target point; Determine a target vertical array from the virtual aperture array, add a Hanning window to the target vertical array, and perform N cf Point Fourier transform is performed, and then modulo is performed to obtain the vertical angle pseudo-spectrum; Filter out a vertical maximum point from the vertical angle pseudo spectrum, wherein the vertical maximum point is a point greater than a vertical angle pseudo spectrum threshold; A quadratic curve interpolation process is performed on the vertical angle pseudo-spectrum according to the index value of the vertical maximum point, so as to obtain the vertical angle value of the target point.

9. The radar echo data processing method according to claim 8, characterized in that: The step of determining a target horizontal array from the virtual aperture array comprises: Determine a first horizontal subarray and a second horizontal subarray from the virtual aperture array, wherein the first horizontal subarray is an arrangement and combination of a receiving antenna group relative to a first transmitting antenna, and the second horizontal subarray is an arrangement and combination of a receiving antenna group relative to a second transmitting antenna, the first transmitting antenna is aligned with the second transmitting antenna in a horizontal direction, and in each round of signal transmission, the first transmitting antenna transmits signals first with the second transmitting antenna; determining a horizontal phase compensation factor according to a velocity dimension parameter in the first horizontal subarray; performing phase compensation on the second horizontal subarray according to the horizontal phase compensation factor; The first horizontal sub-array and the second horizontal sub-array after phase compensation are arranged to obtain a target horizontal array.

10. The radar echo data processing method according to claim 8, characterized in that: The step of determining a target vertical array from the virtual aperture array comprises: Determine a first vertical subarray and a third vertical subarray from the virtual aperture array, wherein the first vertical subarray is an arrangement and combination of the receiving antenna group relative to the first transmitting antenna, and the third vertical subarray is an arrangement and combination of the receiving antenna group relative to the third transmitting antenna, and in each round of signal transmission, the third transmitting antenna transmits signals first with the first transmitting antenna; Determining a vertical phase compensation factor according to a velocity dimension parameter in the third vertical subarray; performing phase compensation on the first vertical subarray according to the vertical phase compensation factor; The third vertical sub-array and the phase-compensated first vertical sub-array are arranged to obtain a target vertical array.

11. The radar echo data processing method according to claim 7, characterized in that: Before determining the points above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data as target points, the method further includes: Filter the radar echo data to remove low-frequency components; Perform range Fourier transform and Doppler fast Fourier transform on the radar echo data after removing the low-frequency components to obtain the RD domain signal spectrum; Performing modulus calculation on the RD domain signal spectrum to obtain a modulus value of the RD domain signal spectrum; Perform incoherent superposition on the modulus values ​​of the RD domain signal spectrum to obtain the RD domain signal spectrum amplitude; The one-dimensional distance spectrum is obtained according to the RD domain signal spectrum amplitude.

12. A radar echo data processing device, characterized in that: The device comprises: A processing unit, configured to select a first preset number of reference points from all target points, and use the remaining target points as non-reference points, wherein the signal-to-noise ratio of any of the reference points is greater than the signal-to-noise ratio of the non-reference points, and the target points are points above a one-dimensional distance threshold in a one-dimensional range spectrum corresponding to radar echo data; The processing unit is further used to classify all non-reference points according to the reference points to determine a target category, wherein the number of target points in the target category is greater than or equal to a second preset number; The output unit is used to output target parameter information of the target points in the target category.

13. The radar echo data processing device according to claim 12, characterized in that: The device comprises: The processing unit is used to determine the points above the one-dimensional distance threshold in the one-dimensional distance spectrum corresponding to the radar echo data as target points; and is also used to obtain target parameter information corresponding to the target points.

14. A radar device, characterized in that: The radar device comprises M first receiving antenna units, N second receiving antenna units, K transmitting antenna units and a signal processing module, wherein the M first receiving antenna units are arranged in a horizontal direction with a first fixed spacing, the N second receiving antenna units are arranged in a target direction, the angle between the target direction and the horizontal direction is a first preset angle value, the spacing between any two of the second receiving antenna units is the first fixed spacing, at least two of the transmitting antenna units are arranged in the horizontal direction with a second fixed spacing, and at least two of the transmitting antenna units are arranged in the target direction with a third fixed spacing, wherein M≥4, N≥2, and K≥3; The signal processing module is connected to the first receiving antenna unit, the second receiving antenna unit and the transmitting antenna unit respectively, and is used to process the radar echo data according to the method described in any one of claims 1-11.

15. A movable platform, characterized in that: A radar device comprising the radar device of claim 14.

16. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 1 to 11 is implemented.

17. A terminal device, characterized in that: include: A processor and a memory, the memory being used to store one or more programs; When the one or more programs are executed by the processor, the method according to any one of claims 1 to 11 is implemented.

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