A millimeter wave radar constant false alarm rate detection method and device

Abstract

The embodiment of the present invention provides a millimeter wave radar constant false alarm rate detection method and device, which receives the signal of the frequency modulated continuous wave FMCW signal emitted by the millimeter wave radar after being reflected by the detection target, performs preset signal processing on the received signal to obtain the range-Doppler matrix, and calculates the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix; based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and detection target probability distribution, the noise screening threshold under the two-dimensional plane average noise power is calculated by using the N-P criterion; according to the noise screening threshold, the noise point is screened for the range-Doppler matrix to obtain a set of candidate target points; two-dimensional windowed constant false alarm detection is used to determine the target point, and the detection result for the detection target is determined based on the target point. The complexity of target detection is reduced and the accuracy of target detection is improved.

Description

Technical Field

[0001] The present invention relates to the field of radar detection technology, and in particular to a millimeter wave radar constant false alarm rate detection method and device. Background Art

[0002] Frequency Modulated Continuous Wave (FMCW) is widely used in various short-range radars, anti-collision radars, etc. Constant False Alarm Rate (CFAR) algorithm is a common technology for detecting the presence of target signals in radar systems and has always been the focus of research in the radar field. At present, in the field of FMCW millimeter wave radar measurement, the one-dimensional CFAR detection algorithm is mainly used to detect the target on the echo signal containing the target and interference. Specifically, the range Doppler map (RDM) containing the target information is first traversed and searched in the distance dimension to obtain the preliminary detection result, and then, based on the result obtained in the previous step, the speed dimension is traversed to finally obtain the distance and speed information of the detected target. However, this target detection algorithm needs to perform a one-dimensional CFAR detection algorithm on the different dimensions of the RDM to determine the distance and speed information of the target. In actual scenarios, the algorithm has a high complexity and cannot meet the real-time requirements of radar detection. Moreover, as the number of sampling points of the transmitted signal increases, the dimension of the obtained RDM continues to grow, resulting in an exponential increase in the detection complexity. Summary of the invention

[0003] The purpose of the embodiments of the present invention is to provide a millimeter wave radar constant false alarm rate detection method and device, so as to reduce the complexity of target detection and improve the accuracy of target detection.

[0004] To achieve the above object, an embodiment of the present invention provides a millimeter wave radar constant false alarm rate detection method, the method comprising:

[0005] A frequency modulated continuous wave (FMCW) signal emitted by a millimeter wave radar is received after being reflected by a detection target, and a preset signal processing is performed on the received signal to obtain a range-Doppler matrix, wherein the range-Doppler matrix represents the signal strength at detection points of different distances and different speeds; the detection points include noise points, target points, and clutter interference points;

[0006] Calculating the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix;

[0007] Based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target detection probability distribution, the noise screening threshold under the average noise power of the two-dimensional plane is calculated by using the NP criterion;

[0008] According to the noise screening threshold, the range-Doppler matrix is ​​screened for noise points to obtain a set of candidate target points;

[0009] For the candidate target point set, two-dimensional windowed constant false alarm detection is adopted to determine the target point, and a detection result for the detected target is determined based on the target point.

[0010] Optionally, the step of calculating the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix includes:

[0011] The range-Doppler matrix is ​​averaged in the distance dimension, and a windowing method is used to obtain the average signal strength of the distance dimension in each window according to a preset windowing length of the distance dimension;

[0012] The minimum value of the average value of the signal strength in the distance dimension in each window is determined as the average noise power in the distance dimension;

[0013] The range-Doppler matrix is ​​averaged in the velocity dimension, and the signal strength average value of the velocity dimension in each window is obtained by using a windowing method according to a preset windowing length of the velocity dimension;

[0014] The minimum value of the average value of the signal strength in the velocity dimension in each window is determined as the average noise power in the velocity dimension;

[0015] The average noise power in the distance dimension and the average noise power in the speed dimension are averaged to obtain the two-dimensional plane average noise power.

[0016] Optionally, the step of screening noise points in the range-Doppler matrix according to the noise screening threshold to obtain a set of candidate target points includes:

[0017] Detection points in the range-Doppler matrix whose signal strength is less than the noise screening threshold are screened out, and the remaining detection points are determined as candidate target points.

[0018] Optionally, the step of determining the target point by using two-dimensional windowed constant false alarm detection for the candidate target point set includes:

[0019] For each detection point in the candidate target point set, a detection area centered on the detection point is determined according to a preset two-dimensional detection window;

[0020] According to the signal strength of the detection point in the detection area, a constant false alarm rate detection algorithm is used to determine the clutter average power in the distance dimension and the speed dimension of the detection point, and according to the predetermined distance dimension threshold coefficient and speed dimension threshold coefficient, a detection threshold value in the distance dimension and a detection threshold value in the speed dimension for the detection point are respectively determined;

[0021] Taking the average of the detection threshold value of the distance dimension and the detection threshold value of the speed dimension for the detection point, to obtain a decision threshold value for the detection point;

[0022] Whether the detection point is a target point is determined based on the relationship between the signal strength of the detection point and the decision threshold value for the detection point; when the signal strength of the detection point is not less than the decision threshold value for the detection point, the detection point is a target point; when the signal strength of the detection point is less than the decision threshold value for the detection point, the detection point is a clutter interference point.

[0023] To achieve the above object, an embodiment of the present invention further provides a millimeter wave radar constant false alarm rate detection device, the device comprising:

[0024] A processing module is used to receive a signal of a frequency modulated continuous wave (FMCW) signal emitted by a millimeter wave radar after being reflected by a detection target, and perform preset signal processing on the received signal to obtain a range-Doppler matrix, wherein the range-Doppler matrix represents the signal strength at detection points of different distances and different speeds; the detection points include noise points, target points, and clutter interference points;

[0025] A first calculation module, used for calculating the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix;

[0026] A second calculation module is used to calculate the noise screening threshold under the average noise power of the two-dimensional plane using the NP criterion based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target detection probability distribution;

[0027] A screening module, used to screen noise points in the range-Doppler matrix according to the noise screening threshold to obtain a set of candidate target points;

[0028] The detection module is used to determine the target point by using two-dimensional windowed constant false alarm detection for the candidate target point set, and determine the detection result for the detected target based on the target point.

[0029] Optionally, the first computing module is specifically configured to:

[0030] The range-Doppler matrix is ​​averaged in the distance dimension, and a windowing method is used to obtain the average signal strength of the distance dimension in each window according to a preset windowing length of the distance dimension;

[0031] The minimum value of the average value of the signal strength in the distance dimension in each window is determined as the average noise power in the distance dimension;

[0032] The range-Doppler matrix is ​​averaged in the velocity dimension, and the signal strength average value of the velocity dimension in each window is obtained by using a windowing method according to a preset windowing length of the velocity dimension;

[0033] The minimum value of the average value of the signal strength in the velocity dimension in each window is determined as the average noise power in the velocity dimension;

[0034] The average noise power in the distance dimension and the average noise power in the speed dimension are averaged to obtain the two-dimensional plane average noise power.

[0035] Optionally, the screening module is specifically used to:

[0036] Detection points in the range-Doppler matrix whose signal strength is less than the noise screening threshold are screened out, and the remaining detection points are determined as candidate target points.

[0037] Optionally, the detection module is specifically used to:

[0038] For each detection point in the candidate target point set, a detection area centered on the detection point is determined according to a preset two-dimensional detection window;

[0039] According to the signal strength of the detection point in the detection area, a constant false alarm rate detection algorithm is used to determine the clutter average power in the distance dimension and the speed dimension of the detection point, and according to the predetermined distance dimension threshold coefficient and speed dimension threshold coefficient, a detection threshold value in the distance dimension and a detection threshold value in the speed dimension for the detection point are respectively determined;

[0040] Taking the average of the detection threshold value of the distance dimension and the detection threshold value of the speed dimension for the detection point, to obtain a decision threshold value for the detection point;

[0041] Whether the detection point is a target point is determined based on the relationship between the signal strength of the detection point and the decision threshold value for the detection point; when the signal strength of the detection point is not less than the decision threshold value for the detection point, the detection point is a target point; when the signal strength of the detection point is less than the decision threshold value for the detection point, the detection point is a clutter interference point.

[0042] To achieve the above-mentioned purpose, an embodiment of the present application further provides an electronic device, including a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus;

[0043] Memory, used to store computer programs;

[0044] The processor is used to implement any of the above method steps when executing the program stored in the memory.

[0045] To achieve the above objectives, an embodiment of the present application further provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any of the above method steps is implemented.

[0046] Beneficial effects of the embodiments of the present invention:

[0047] The millimeter wave radar constant false alarm rate detection method and device provided in the embodiment of the present invention are applied to receive the frequency modulated continuous wave FMCW signal emitted by the millimeter wave radar after being reflected by the detection target, and the received signal is processed by a preset signal to obtain the range-Doppler matrix X MN , the range-Doppler matrix X MN The signal strength at the detection points of different distances and different speeds is represented; the detection points include noise points, target points and clutter interference points; according to the range-Doppler matrix, the two-dimensional plane average noise power of the detection points is calculated; based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and detection target probability distribution, the NP criterion is used to calculate the noise screening threshold under the two-dimensional plane average noise power; according to the noise screening threshold, the noise points of the range-Doppler matrix are screened to obtain a set of candidate target points; for the set of candidate target points, a two-dimensional windowed constant false alarm detection is used to determine the target point, and the detection result for the detected target is determined based on the target point.

[0048] It can be seen that in the embodiment of the present invention, the following characteristics of the field of millimeter wave radar target detection are taken into account: first, the interval between frames of the FMCW millimeter wave detection radar receiver is extremely short, and the noise power in the distance-Doppler matrix obtained by processing the received signal of each frame is almost unchanged; second, the high resolution characteristics of the millimeter wave radar in the distance and speed dimensions result in most of the noise points in the obtained distance-Doppler matrix. Therefore, a noise point screening plane is constructed to remove unnecessary noise points in the distance-Doppler matrix. Compared with the existing algorithm for detecting useless noise points in the distance and speed dimensions, the complexity of target detection is greatly reduced. In addition, the embodiment of the present invention adopts two-dimensional windowed constant false alarm detection, and at the same time analyzes the clutter interference in the detection area of ​​the detection point distance dimension and the speed dimension and comprehensively determines the final decision threshold. Compared with one-dimensional constant false alarm rate detection, the accuracy of target detection is effectively improved.

[0049] Of course, it is not necessary to achieve all of the advantages described above at the same time to implement any product or method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0051] Figure 1 A schematic diagram of a flow chart of a millimeter wave radar constant false alarm rate detection method provided by an embodiment of the present invention;

[0052] Figure 2 A schematic diagram of a process for calculating the average noise power of a two-dimensional plane of a detection point provided by an embodiment of the present invention;

[0053] Figure 3 A schematic diagram of a process of two-dimensional windowed constant false alarm detection provided by an embodiment of the present invention;

[0054] Figure 4 A schematic diagram of the structure of a millimeter wave radar constant false alarm rate detection device provided by an embodiment of the present invention;

[0055] Figure 5 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0057] In order to solve the technical problem of high computational complexity of existing radar detection, the embodiments of the present invention provide a millimeter wave radar constant false alarm rate detection method, device, electronic device and computer readable storage medium.

[0058] See also Figure 1 , Figure 1 A flow chart of a millimeter wave radar constant false alarm rate detection method provided by an embodiment of the present invention, the method comprising:

[0059] S101: receiving a frequency modulated continuous wave (FMCW) signal emitted by a millimeter wave radar after being reflected by a detection target, performing preset signal processing on the received signal, and obtaining a range-Doppler matrix, where the range-Doppler matrix represents signal strengths at detection points at different distances and different speeds; the detection points include noise points, target points, and clutter interference points.

[0060] In the embodiment of the present invention, in order to detect the target, that is, to obtain the distance between the target and itself and the speed information of the target, the millimeter wave radar can send a frequency modulated continuous wave FMCW signal to the detection target, then receive the signal after the FMCW signal is reflected by the detection target, and perform preset signal processing on the received signal to obtain the range-Doppler matrix X MN , the range-Doppler matrix X MN Indicates the signal strength at detection points of different distances and speeds. The detection points include noise points, target points, and interference points.

[0061] In the embodiment of the present invention, the millimeter wave radar performs preset signal processing on the received reflected signal, which may include frequency mixing filtering, sampling discreteness, and two-dimensional Fourier transform processing.

[0062] Specifically, the received signal is first subjected to mixing and filtering processing to obtain an intermediate frequency signal containing the distance and speed information of the detection target, the intermediate frequency signal is sampled and discretized to obtain a discrete signal, and then the sampled intermediate frequency discrete signal is subjected to a two-dimensional Fourier transform in the distance dimension and the speed dimension to convert the time domain information into the frequency domain, thereby obtaining a range Doppler spectrum containing the distance information and speed information of the detection target. The range Doppler spectrum is in the form of a two-dimensional matrix, containing the signal strength of detection points at different distances and different speeds, wherein the detection points include noise points, target points, and clutter interference points. For ease of description, in the embodiment of the present invention, the range Doppler spectrum is recorded as a range-Doppler matrix, and the symbol X is used. MN Represents. The range-Doppler matrix X MN The element x in ij Indicates the signal strength of the detection point corresponding to the i-th distance and j-th speed.

[0063] S102: Calculate the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix.

[0064] In the embodiment of the present invention, in order to reduce the complexity of target detection, a noise screening plane may be constructed to screen the detection points in the range-Doppler matrix.

[0065] Specifically, the following characteristics of the millimeter wave radar target detection field are taken into account: first, the interval between frames of the FMCW millimeter wave detection radar receiver is extremely short, and the noise power in the range-Doppler matrix obtained by processing the received signal of each frame is almost unchanged; second, the high resolution characteristics of the millimeter wave radar in the distance and speed dimensions result in most of the obtained range-Doppler matrix being noise points. Therefore, a noise screening plane can be constructed to screen out noise points to reduce the complexity of subsequent target detection.

[0066] Before constructing the noise screening plane, it is necessary to calculate the average noise power of the two-dimensional plane of the detection point, that is, the average noise power in the speed dimension and the distance dimension.

[0067] In an embodiment of the present invention, step S102 may specifically include the following detailed steps:

[0068] S201: Calculate the mean of the range-Doppler matrix in the distance dimension, and use a windowing method to calculate the average signal strength of the distance dimension in each window according to a preset windowing length of the distance dimension.

[0069] S202: Determine the minimum value of the average values ​​of the signal strengths in the distance dimension in each window as the average noise power in the distance dimension.

[0070] In the embodiment of the present invention, the range-Doppler matrix X MN It is in the form of a two-dimensional matrix, with the horizontal axis representing the distance dimension and a length of M, and the vertical axis representing the speed dimension and a length of N.

[0071] In the embodiment of the present invention, X MN The average value is calculated in the distance dimension to obtain the curve relationship between the average signal strength of the detection point and the distance. The windowing method is used to obtain the average signal strength of the data in the window, and the lowest value is taken as the average noise power N in the distance dimension under the current measurement conditions. R .

[0072] S203: Calculate the mean of the range-Doppler matrix in the velocity dimension, and use a windowing method to calculate the average signal strength of the velocity dimension in each window according to a preset windowing length of the velocity dimension;

[0073] S204: Determine the minimum value of the average values ​​of the signal strengths in the speed dimension in each window as the average noise power in the speed dimension.

[0074] Similarly, we can MN The average value is calculated in the speed dimension to obtain the curve relationship between the average signal strength of the detection point and the speed. The windowing method is used to obtain the average signal strength of the data in the window, and the lowest value is taken as the average noise power N in the speed dimension under the current measurement conditions. D .

[0075] S205: taking the average of the average noise power in the distance dimension and the average noise power in the speed dimension to obtain the average noise power in the two-dimensional plane.

[0076] Average noise power in the distance dimension N R and the average noise power N in the velocity dimension D Find the average value and get the average noise power N in the two-dimensional plane O .

[0077] S103: Based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target signal probability distribution, a noise screening threshold under the average noise power in a two-dimensional plane is calculated based on the NP criterion.

[0078] In the embodiment of the present invention, the false alarm probability can be set according to requirements.

[0079] Those skilled in the art will appreciate that noise and clutter interference all obey a certain distribution, for example, noise obeys a Gaussian distribution, and clutter interference obeys a Gaussian or Weibull distribution. On this basis, the NP criterion can be used to calculate the average noise power N in the two-dimensional plane when a constant false alarm probability is satisfied. O The noise screening threshold under . Among them, the NP criterion is the Neyman-Pearson criterion, which is widely used in hypothesis testing.

[0080] Specifically, in the process of calculating the noise screening threshold, a hypothesis test model for target noise screening can be established:

[0081]

[0082] Among them, H0 means that the detection value is only noise, and H1 means that the current detection value contains not only noise but also target or clutter signals.

[0083] When the noise, clutter and target signal all obey a certain distribution, the optimal noise screening threshold F under the average noise power of the two-dimensional plane can be obtained according to the NP criterion, F = αN O , α is the threshold coefficient obtained.

[0084] Among them, the false alarm probability is the probability that the current detection point is mistaken for the target point, which is expressed as Where f represents the probability density function, and the preset constant false alarm rate is P fa , then according to The corresponding threshold coefficient α can be obtained.

[0085] The above is only an example. For a method of calculating a threshold coefficient using the NP criterion based on a probability density function and a preset constant false alarm rate, reference may also be made to related technologies.

[0086] S104: Screening noise points in the range-Doppler matrix according to the noise screening threshold to obtain a set of candidate target points.

[0087] In the embodiment of the present invention, after the noise screening threshold is obtained, noise points can be screened on the range-Doppler matrix.

[0088] In one embodiment of the present invention, detection points in the range-Doppler matrix whose signal strength is less than the noise screening threshold are screened out, and the remaining detection points are determined as candidate target points.

[0089] Specifically, when the signal strength of a detection point in the range-Doppler matrix is ​​less than the noise screening threshold, the detection point is determined to be a noise point and is screened out; when the signal strength of a detection point in the range-Doppler matrix is ​​not less than the noise screening threshold, the detection point is determined to be a possible target point and is retained. The retained detection points are all candidate target points, constituting a candidate target point set.

[0090] S105: for the candidate target point set, a two-dimensional windowed constant false alarm detection is used to determine the target point, and a detection result for the detection target is determined based on the target point.

[0091] In one embodiment of the present invention, see Figure 3 , Figure 3 A schematic diagram of a flow chart of two-dimensional windowed constant false alarm detection provided by an embodiment of the present invention, the above step S105 may specifically include the following detailed steps:

[0092] S301: For each detection point in the candidate target point set, a detection area centered on the detection point is determined according to a preset two-dimensional detection window.

[0093] In the embodiment of the present invention, the number of retained candidate target points has been greatly reduced compared to the total number of detection points before noise point screening. For each candidate target point, steps S301-S304 can be executed to determine whether the candidate target point is a target point or a clutter interference point.

[0094] For the sake of convenience, taking one of the candidate target points as an example, the detection area for the detection point can be determined. A two-dimensional detection window can be preset, and the size of the two-dimensional detection window can be set according to the needs, so as to determine the detection area centered on the detection point.

[0095] S302: According to the signal strength of the detection point in the detection area, a constant false alarm rate detection algorithm is used to determine the average clutter power in the distance dimension and the speed dimension of the detection point, and according to the predetermined distance dimension threshold coefficient and speed dimension threshold coefficient, the detection threshold value in the distance dimension and the detection threshold value in the speed dimension for the detection point are determined respectively.

[0096] In the embodiment of the present invention, the following hypothesis testing model can be established for the current detection point:

[0097]

[0098] Among them, H0 indicates that the current detection point is a clutter interference point, and H1 indicates that the current detection value is a target point. Since the clutter interference power is random and fluctuates greatly, a two-dimensional window is used to obtain the interference power around the current detection point as the clutter interference power during detection.

[0099] When the clutter and target signals follow a certain distribution, the constant false alarm rate detection algorithm can be used to determine the average clutter power in the distance dimension of the current detection point based on the signal strength of the detection point in the detection area. and the average clutter power in the velocity dimension

[0100] Furthermore, according to the false alarm probabilities set in the distance and speed dimensions, the threshold coefficients α1 and α2 are obtained respectively, and the detection threshold values ​​of the detection unit in the distance and speed dimensions are calculated as follows: and

[0101] The threshold coefficients α1 and α2 may also be calculated based on a probability density function and a preset constant false alarm rate using the NP criterion, which will not be described in detail.

[0102] S303: taking the average of the detection threshold value of the distance dimension and the detection threshold value of the speed dimension for the detection point to obtain a decision threshold value for the detection point.

[0103] S304: Determine whether the detection point is a target point based on the relationship between the signal strength of the detection point and the decision threshold value for the detection point; when the signal strength of the detection point is not less than the decision threshold value for the detection point, the detection point is a target point; when the signal strength of the detection point is less than the decision threshold value for the detection point, the detection point is a clutter interference point.

[0104] In the embodiment of the present invention, the average value of the detection thresholds required in the distance and speed dimensions may be taken as the final decision threshold of the current detection point and a decision may be made.

[0105] If the signal strength of the detection point is greater than or equal to the corresponding decision threshold, the detection point is determined to be a target point; if the signal strength of the detection point is less than the corresponding decision threshold, the detection point is determined to be a clutter interference point.

[0106] Through the above steps, multiple target points in the range-Doppler matrix can be detected. The horizontal coordinate of the target point represents the distance information, and the vertical coordinate represents the speed information. The distance information and speed information of these target points can represent the detection results for the detection target.

[0107] In the related art, a corresponding detection result schematic diagram may be drawn based on the distance information and speed information of multiple target points to more intuitively represent the detection result for the target.

[0108] The millimeter wave radar constant false alarm rate detection method provided by the embodiment of the present invention is applied to receive the frequency modulated continuous wave FMCW signal emitted by the millimeter wave radar after being reflected by the detection target, and the received signal is subjected to preset signal processing to obtain the range-Doppler matrix X MN , the range-Doppler matrix X MN The signal strength at the detection points of different distances and different speeds is represented; the detection points include noise points, target points and clutter interference points; according to the range-Doppler matrix, the two-dimensional plane average noise power of the detection points is calculated; based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and detection target probability distribution, the NP criterion is used to calculate the noise screening threshold under the two-dimensional plane average noise power; according to the noise screening threshold, the noise points of the range-Doppler matrix are screened to obtain a set of candidate target points; for the set of candidate target points, a two-dimensional windowed constant false alarm detection is used to determine the target point, and the detection result for the detected target is determined based on the target point.

[0109] It can be seen that in the embodiment of the present invention, the following characteristics of the millimeter wave radar target detection field are taken into account: first, the interval between frames of the FMCW millimeter wave detection radar receiver is extremely short, and the noise power in the distance-Doppler matrix obtained by processing the received signal of each frame is almost unchanged; second, the high resolution characteristics of the millimeter wave radar in the distance and speed dimensions result in most of the noise points in the obtained distance-Doppler matrix. Therefore, a noise point screening plane is constructed to remove unnecessary noise points in the distance-Doppler matrix. Compared with the existing algorithm for detecting useless noise points in the distance and speed dimensions, the complexity of target detection is greatly reduced. In addition, the embodiment of the present invention adopts two-dimensional windowed constant false alarm detection, and at the same time analyzes the clutter interference in the detection area of ​​the detection point distance dimension and the speed dimension and comprehensively determines the final decision threshold, which effectively improves the detection accuracy compared to the one-dimensional constant false alarm rate detection.

[0110] Corresponding to the millimeter wave radar constant false alarm rate detection method embodiment provided in the embodiment of the present invention, the embodiment of the present invention also provides a millimeter wave radar constant false alarm rate detection device, see Figure 4 , the device may include the following modules:

[0111] The processing module 401 is used to receive the signal of the frequency modulated continuous wave FMCW signal emitted by the millimeter wave radar after being reflected by the detection target, and perform preset signal processing on the received signal to obtain a range-Doppler matrix, where the range-Doppler matrix represents the signal strength at the detection points of different distances and different speeds; the detection points include noise points, target points and clutter interference points;

[0112] A first calculation module 402 is used to calculate the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix;

[0113] The second calculation module 403 is used to calculate the noise screening threshold under the average noise power in the two-dimensional plane by using the NP criterion based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target detection probability distribution;

[0114] A screening module 404 is used to screen noise points in the range-Doppler matrix according to a noise screening threshold to obtain a set of candidate target points;

[0115] The detection module 405 is used to determine the target point by using two-dimensional windowed constant false alarm detection for the candidate target point set, and determine the detection result for the detected target based on the target point.

[0116] In one embodiment of the present invention, the first calculation module 402 may be specifically configured to:

[0117] The range-Doppler matrix is ​​averaged in the distance dimension, and the signal strength average value in the distance dimension in each window is obtained by using a windowing method according to a preset windowing length in the distance dimension;

[0118] The minimum value of the average value of the signal strength in the distance dimension in each window is determined as the average noise power in the distance dimension;

[0119] The range-Doppler matrix is ​​averaged in the velocity dimension, and the signal strength average value of the velocity dimension in each window is obtained by using the windowing method according to the preset windowing length of the velocity dimension;

[0120] The minimum value of the average value of the signal strength in the velocity dimension in each window is determined as the average noise power in the velocity dimension;

[0121] The average noise power in the distance dimension and the average noise power in the speed dimension are averaged to obtain the average noise power in the two-dimensional plane.

[0122] In one embodiment of the present invention, the screening module 404 may be specifically used to:

[0123] The detection points whose signal strength in the range-Doppler matrix is ​​less than the noise screening threshold are screened out, and the remaining detection points are determined as candidate target points.

[0124] In one embodiment of the present invention, the detection module 405 may be specifically used for:

[0125] For each detection point in the candidate target point set, a detection area centered on the detection point is determined according to a preset two-dimensional detection window;

[0126] According to the signal strength of the detection point in the detection area, a constant false alarm rate detection algorithm is used to determine the average clutter power in the distance dimension and the speed dimension of the detection point, and according to the predetermined distance dimension threshold coefficient and speed dimension threshold coefficient, the detection threshold value in the distance dimension and the detection threshold value in the speed dimension for the detection point are determined respectively;

[0127] The detection threshold value of the distance dimension and the detection threshold value of the speed dimension for the detection point are averaged to obtain the decision threshold value for the detection point;

[0128] Whether the detection point is a target point is determined based on the relationship between the signal strength of the detection point and the decision threshold value for the detection point; when the signal strength of the detection point is not less than the decision threshold value for the detection point, the detection point is a target point; when the signal strength of the detection point is less than the decision threshold value for the detection point, the detection point is a clutter interference point.

[0129] The millimeter wave radar constant false alarm rate detection device provided by the embodiment of the present invention is used to receive the frequency modulated continuous wave FMCW signal emitted by the millimeter wave radar after being reflected by the detection target, and the received signal is processed by a preset signal to obtain the range-Doppler matrix X MN , the range-Doppler matrix X MN The signal strength at the detection points of different distances and different speeds is represented; the detection points include noise points, target points and clutter interference points; according to the range-Doppler matrix, the two-dimensional plane average noise power of the detection points is calculated; based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and detection target probability distribution, the NP criterion is used to calculate the noise screening threshold under the two-dimensional plane average noise power; according to the noise screening threshold, the noise points of the range-Doppler matrix are screened to obtain a set of candidate target points; for the set of candidate target points, a two-dimensional windowed constant false alarm detection is used to determine the target point, and the detection result for the detected target is determined based on the target point.

[0130] It can be seen that in the embodiment of the present invention, the following characteristics of the field of millimeter wave radar target detection are taken into account: first, the interval between frames of the FMCW millimeter wave detection radar receiver is extremely short, and the noise power in the distance-Doppler matrix obtained by processing the received signal of each frame is almost unchanged; second, the high resolution characteristics of the millimeter wave radar in the distance and speed dimensions result in most of the noise points in the obtained distance-Doppler matrix. Therefore, a noise point screening plane is constructed to remove unnecessary noise points in the distance-Doppler matrix. Compared with the existing algorithm for detecting useless noise points in the distance and speed dimensions, the complexity of target detection is greatly reduced. In addition, the embodiment of the present invention adopts two-dimensional windowed constant false alarm detection, and at the same time analyzes the clutter interference in the detection area of ​​the detection point distance dimension and the speed dimension and comprehensively determines the final decision threshold. Compared with one-dimensional constant false alarm rate detection, the accuracy of target detection is effectively improved.

[0131] Among them, the method and the device are based on the same application concept. Since the method and the device solve the problem in a similar principle, the implementation of the device and the method can refer to each other, and the repeated parts will not be repeated.

[0132] The embodiment of the present invention further provides an electronic device, such as Figure 5 As shown, it includes a processor 501, a communication interface 502, a memory 503 and a communication bus 504, wherein the processor 501, the communication interface 502, and the memory 503 communicate with each other through the communication bus 504.

[0133] Memory 503, used for storing computer programs;

[0134] The processor 501 is used to execute the program stored in the memory 503, and implements the following steps:

[0135] Receive the frequency modulated continuous wave (FMCW) signal emitted by the millimeter wave radar after being reflected by the detection target, perform preset signal processing on the received signal, and obtain a range-Doppler matrix. The range-Doppler matrix represents the signal strength at detection points of different distances and different speeds; the detection points include noise points, target points, and clutter interference points;

[0136] According to the range-Doppler matrix, the average noise power of the two-dimensional plane of the detection point is calculated;

[0137] Based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target detection probability distribution, the NP criterion is used to calculate the noise screening threshold under the average noise power in the two-dimensional plane.

[0138] According to the noise screening threshold, the noise points of the range-Doppler matrix are screened to obtain a set of candidate target points;

[0139] For the candidate target point set, a two-dimensional windowed constant false alarm detection is used to determine the target point, and the detection result for the detected target is determined based on the target point.

[0140] The communication bus mentioned in the above electronic device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. The communication bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, only one thick line is used in the figure, but it does not mean that there is only one bus or one type of bus.

[0141] The communication interface is used for communication between the above electronic device and other devices.

[0142] The memory may include a random access memory (RAM) or a non-volatile memory (NVM), such as at least one disk memory. Optionally, the memory may also be at least one storage device located away from the aforementioned processor.

[0143] The above-mentioned processor can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can 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 gate or transistor logic devices, discrete hardware components.

[0144] The electronic device provided by the embodiment of the present invention is used to receive the frequency modulated continuous wave FMCW signal emitted by the millimeter wave radar after the signal is reflected by the detection target, and the received signal is processed by a preset signal to obtain the range-Doppler matrix X MN , the range-Doppler matrix X MNThe signal strength at the detection points of different distances and different speeds is represented; the detection points include noise points, target points and clutter interference points; according to the range-Doppler matrix, the two-dimensional plane average noise power of the detection points is calculated; based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and detection target probability distribution, the NP criterion is used to calculate the noise screening threshold under the two-dimensional plane average noise power; according to the noise screening threshold, the noise points of the range-Doppler matrix are screened to obtain a set of candidate target points; for the set of candidate target points, a two-dimensional windowed constant false alarm detection is used to determine the target point, and the detection result for the detected target is determined based on the target point.

[0145] It can be seen that in the embodiment of the present invention, the following characteristics of the field of millimeter wave radar target detection are taken into account: first, the interval between frames of the FMCW millimeter wave detection radar receiver is extremely short, and the noise power in the distance-Doppler matrix obtained by processing the received signal of each frame is almost unchanged; second, the high resolution characteristics of the millimeter wave radar in the distance and speed dimensions result in most of the noise points in the obtained distance-Doppler matrix. Therefore, a noise point screening plane is constructed to remove unnecessary noise points in the distance-Doppler matrix. Compared with the existing algorithm for detecting useless noise points in the distance and speed dimensions, the complexity of target detection is greatly reduced. In addition, the embodiment of the present invention adopts two-dimensional windowed constant false alarm detection, and at the same time analyzes the clutter interference in the detection area of ​​the detection point distance dimension and the speed dimension and comprehensively determines the final decision threshold. Compared with one-dimensional constant false alarm rate detection, the accuracy of target detection is effectively improved.

[0146] In another embodiment of the present invention, a computer-readable storage medium is provided, in which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above-mentioned millimeter-wave radar constant false alarm rate detection methods are implemented.

[0147] In another embodiment of the present invention, a computer program product including instructions is provided. When the computer program product is run on a computer, the computer executes any of the millimeter wave radar constant false alarm rate detection methods in the above embodiments.

[0148] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented by software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from a website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium (e.g., a solid-state hard disk Solid State Disk (SSD)), etc.

[0149] 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 sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0150] Each embodiment in this specification is described in a related manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the millimeter wave radar constant false alarm rate detection device, electronic device, computer readable storage medium and computer program product embodiments, since they are basically similar to the millimeter wave radar constant false alarm rate detection method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the millimeter wave radar constant false alarm rate detection method embodiment.

[0151] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention are included in the protection scope of the present invention.

Claims

1. A millimeter wave radar constant false alarm rate detection method, characterized in that: The method comprises: A frequency modulated continuous wave (FMCW) signal emitted by a millimeter wave radar is received after being reflected by a detection target, and a preset signal processing is performed on the received signal to obtain a range-Doppler matrix, wherein the range-Doppler matrix represents the signal strength at detection points of different distances and different speeds; the detection points include noise points, target points, and clutter interference points; Calculating the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix; Based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target detection probability distribution, the noise screening threshold under the average noise power of the two-dimensional plane is calculated by using the NP criterion; According to the noise screening threshold, the range-Doppler matrix is ​​screened for noise points to obtain a set of candidate target points; For the candidate target point set, a two-dimensional windowed constant false alarm detection is used to determine a target point, and a detection result for the detection target is determined based on the target point; The step of calculating the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix comprises: The range-Doppler matrix is ​​averaged in the distance dimension, and a windowing method is used to obtain the average signal strength of the distance dimension in each window according to a preset windowing length of the distance dimension; The minimum value of the average value of the signal strength in the distance dimension in each window is determined as the average noise power in the distance dimension; The range-Doppler matrix is ​​averaged in the velocity dimension, and the signal strength average value of the velocity dimension in each window is obtained by using a windowing method according to a preset windowing length of the velocity dimension; The minimum value of the average value of the signal strength in the velocity dimension in each window is determined as the average noise power in the velocity dimension; Taking the average of the average noise power in the distance dimension and the average noise power in the speed dimension to obtain the average noise power in the two-dimensional plane; The step of determining the target point by using two-dimensional windowed constant false alarm detection for the candidate target point set comprises: For each detection point in the candidate target point set, a detection area centered on the detection point is determined according to a preset two-dimensional detection window; According to the signal strength of the detection point in the detection area, a constant false alarm rate detection algorithm is used to determine the clutter average power in the distance dimension and the speed dimension of the detection point, and according to the predetermined distance dimension threshold coefficient and speed dimension threshold coefficient, a detection threshold value in the distance dimension and a detection threshold value in the speed dimension for the detection point are respectively determined; Taking the average of the detection threshold value of the distance dimension and the detection threshold value of the speed dimension for the detection point, to obtain a decision threshold value for the detection point; Whether the detection point is a target point is determined based on the relationship between the signal strength of the detection point and the decision threshold value for the detection point; when the signal strength of the detection point is not less than the decision threshold value for the detection point, the detection point is a target point; when the signal strength of the detection point is less than the decision threshold value for the detection point, the detection point is a clutter interference point.

2. The method according to claim 1, characterized in that: The step of screening noise points on the range-Doppler matrix according to the noise screening threshold to obtain a set of candidate target points includes: Detection points in the range-Doppler matrix whose signal strength is less than the noise screening threshold are screened out, and the remaining detection points are determined as candidate target points.

3. A millimeter wave radar constant false alarm rate detection device, characterized in that: The device comprises: A processing module is used to receive a signal of a frequency modulated continuous wave (FMCW) signal emitted by a millimeter wave radar after being reflected by a detection target, and perform preset signal processing on the received signal to obtain a range-Doppler matrix, wherein the range-Doppler matrix represents the signal strength at detection points of different distances and different speeds; the detection points include noise points, target points, and clutter interference points; A first calculation module, used for calculating the two-dimensional plane average noise power of the detection point according to the range-Doppler matrix; A second calculation module is used to calculate the noise screening threshold under the average noise power of the two-dimensional plane using the NP criterion based on the preset false alarm probability, noise probability distribution, clutter interference probability distribution and target detection probability distribution; A screening module, used to screen noise points in the range-Doppler matrix according to the noise screening threshold to obtain a set of candidate target points; A detection module, for determining a target point by using a two-dimensional windowed constant false alarm detection method for the candidate target point set, and determining a detection result for the detection target based on the target point; The first calculation module is specifically used for: The range-Doppler matrix is ​​averaged in the distance dimension, and a windowing method is used to obtain the average signal strength of the distance dimension in each window according to a preset windowing length of the distance dimension; The minimum value of the average value of the signal strength in the distance dimension in each window is determined as the average noise power in the distance dimension; The range-Doppler matrix is ​​averaged in the velocity dimension, and the signal strength average value of the velocity dimension in each window is obtained by using a windowing method according to a preset windowing length of the velocity dimension; The minimum value of the average value of the signal strength in the velocity dimension in each window is determined as the average noise power in the velocity dimension; Taking the average of the average noise power in the distance dimension and the average noise power in the speed dimension to obtain the average noise power in the two-dimensional plane; The detection module is specifically used for: For each detection point in the candidate target point set, a detection area centered on the detection point is determined according to a preset two-dimensional detection window; According to the signal strength of the detection point in the detection area, a constant false alarm rate detection algorithm is used to determine the clutter average power in the distance dimension and the speed dimension of the detection point, and according to the predetermined distance dimension threshold coefficient and speed dimension threshold coefficient, a detection threshold value in the distance dimension and a detection threshold value in the speed dimension for the detection point are respectively determined; Taking the average of the detection threshold value of the distance dimension and the detection threshold value of the speed dimension for the detection point, to obtain a decision threshold value for the detection point; Whether the detection point is a target point is determined based on the relationship between the signal strength of the detection point and the decision threshold value for the detection point; when the signal strength of the detection point is not less than the decision threshold value for the detection point, the detection point is a target point; when the signal strength of the detection point is less than the decision threshold value for the detection point, the detection point is a clutter interference point.

4. The device according to claim 3, characterized in that The screening module is specifically used for: Detection points in the range-Doppler matrix whose signal strength is less than the noise screening threshold are screened out, and the remaining detection points are determined as candidate target points.

5. An electronic device, characterized in that: It includes a processor, a communication interface, a memory and a communication bus, wherein the processor, the communication interface and the memory communicate with each other through the communication bus; Memory, used to store computer programs; A processor, for implementing the method steps described in any one of claims 1-2 when executing a program stored in a memory.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method steps described in any one of claims 1-2 are implemented.

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