1. A target tracking method of a binary phase modulation array radar is characterized by comprising the following steps:

receiving v sum beams and v difference beams which are spatially synthesized and arranged at intervals by u transmitting signals, wherein the u transmitting signals are transmitted by u transmitting antennas in a mode of homodromous and reverse alternation, and the u transmitting antennas correspond to the u transmitting signals one by one;

obtaining a target parameter of each moving target in k moving targets according to the v sum beams and the v difference beams, wherein v, u and k are positive integers;

and tracking and filtering the target parameters of each moving target, and determining the motion track of each moving target.

2. The method of claim 1, wherein obtaining the target parameters of each of the k moving targets according to the v sum beams and the v difference beams comprises:

acquiring the v sum beams and the v difference beams, and extracting data corresponding to each sum beam in the v sum beams and data corresponding to each difference beam in the v difference beams;

sequentially carrying out one-dimensional fast Fourier transform and two-dimensional fast Fourier transform on the data corresponding to each sum beam and the data corresponding to each difference beam to obtain the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam;

performing Doppler compensation on the two-dimensional fast Fourier transform data corresponding to each difference beam to obtain two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation;

sequentially carrying out non-coherent accumulation and constant false alarm detection on the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation to obtain k moving targets;

and respectively carrying out binary demodulation and angle-of-arrival processing on each moving target in the k moving targets to obtain a target parameter of each moving target in the k moving targets.

3. The method for tracking the target of the binary phase modulation array radar according to claim 2, wherein the sequentially performing one-dimensional fast fourier transform and two-dimensional fast fourier transform on the data corresponding to each sum beam and the data corresponding to each difference beam to obtain the two-dimensional fast fourier transform data corresponding to each sum beam and the two-dimensional fast fourier transform data corresponding to each difference beam comprises:

performing one-dimensional fast fourier transform on the data corresponding to each sum beam and the data corresponding to each difference beam to obtain one-dimensional fast fourier transform data corresponding to each sum beam and one-dimensional fast fourier transform data corresponding to each difference beam;

and performing two-dimensional fast Fourier transform on the one-dimensional fast Fourier transform data corresponding to each sum beam and the one-dimensional fast Fourier transform data corresponding to each difference beam to obtain the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam.

4. The method for tracking the target of the binary phase modulation array radar according to claim 3, wherein the doppler compensating the two-dimensional fast fourier transform data corresponding to each difference beam to obtain the two-dimensional fast fourier transform data corresponding to each difference beam after the phase compensation comprises:

acquiring a data matrix of two-dimensional fast Fourier transform data corresponding to each difference beam, and taking the row vector number L of the data matrix as the Doppler channel number L, wherein L is a positive integer;

and selecting a compensation phase corresponding to each Doppler channel in the L Doppler channels, and determining two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation according to the compensation phase corresponding to each Doppler channel.

5. The method of claim 4, wherein the determining the target parameters of each of the k moving targets by sequentially performing non-coherent accumulation and constant false alarm detection on the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam after the phase compensation comprises:

performing non-coherent accumulation on the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation to obtain a non-coherent accumulation result;

and carrying out constant false alarm detection on the non-coherent accumulation result to obtain k moving targets.

6. The target tracking method of binary phase modulation array radar of claim 5 wherein said target parameters include speed, range and azimuth;

the performing binary demodulation and angle-of-arrival processing on each moving object of the k moving objects respectively to obtain a target parameter of each moving object of the k moving objects includes:

performing binary demodulation on each moving target in the k moving targets to obtain the speed and the distance of each moving target in the k moving targets;

and carrying out angle-of-arrival processing on each moving target in the k moving targets to obtain the azimuth angle of each moving target in the k moving targets.

7. The method for tracking targets of binary phase modulation array radar as claimed in claim 6, wherein said binary demodulating each of said k moving targets to obtain the velocity and distance of each of said k moving targets comprises:

acquiring coordinates of each moving target in the k moving targets in the non-coherent accumulation result, wherein the coordinates comprise an abscissa and an ordinate;

taking the abscissa of each moving target in the k moving targets in the non-coherent accumulation result as a corresponding Doppler channel index number of each moving target, and taking the ordinate of each moving target in the k moving targets in the non-coherent accumulation result as a corresponding distance channel index number of each moving target;

acquiring array radar speed resolution unit parameters and array radar distance resolution unit parameters;

multiplying the Doppler channel index number corresponding to each moving target by the array radar speed resolution unit parameter to obtain the speed of each moving target;

and multiplying the index number of the range channel corresponding to each moving target by the parameter of the array radar range resolution unit to obtain the range of each moving target.

8. The method of claim 7, wherein the performing angle-of-arrival processing on each of the k moving targets to obtain an azimuth angle of each of the k moving targets comprises:

acquiring phase deviation between two adjacent data corresponding to the sum beam and the difference beam;

performing phase compensation on coordinates of each moving target in the data corresponding to the v difference beams in the non-coherent accumulation result by using the phase deviation to obtain compensated data corresponding to the v difference beams;

calculating the v data corresponding to the sum beams and the compensated v data corresponding to the difference beams, and determining the amplitude and phase information of each moving object in each virtual channel of 2v virtual channels;

rearranging the amplitude and phase information in each virtual channel of the 2v virtual channels according to the arrangement sequence of the 2v virtual receiving antenna arrays formed by the array radar to obtain the rearranged amplitude and phase information of the 2v virtual channels;

performing fast Fourier transform on the amplitude and phase information of the rearranged 2v virtual channels to obtain frequency spectrums corresponding to the amplitude and phase information of the rearranged 2v virtual channels;

and selecting an azimuth angle corresponding to the peak position in the frequency spectrum, and taking the azimuth angle corresponding to the peak position as the azimuth angle of each moving target.

9. The method of target tracking for binary phase modulated array radar according to any one of claims 1-8 wherein said receiving said u transmitted signals precedes the spatially synthesized spaced v sum beams and v difference beams, further comprising:

configuring different initial phase sequences for the u transmitting signals;

transmitting the u transmission signals configuring different initial phase sequences.

10. An apparatus for tracking a target of a binary phase modulation array radar, the apparatus comprising:

a receiving module, configured to receive v sum beams and v difference beams spatially synthesized by the u transmit signals and arranged at intervals, where the u transmit signals are transmitted by u transmit antennas in a manner of alternating in a same direction and in a reverse direction, and the u transmit antennas correspond to the u transmit signals one to one;

a target parameter determining module, configured to obtain a target parameter of each moving target of k moving targets according to the v sum beams and the v difference beams, where u, v, and k are positive integers;

and the motion track determining module is used for tracking and filtering the target parameters of each motion target and determining the motion track of each motion target.

Background

With the development of the automobile industry, the automatic driving technology is more mature, the dependence degree of an intelligent vehicle on various sensor devices is higher and higher, and the requirement on the technical indexes of various vehicle body sensors is also higher and higher. Millimeter wave radar is an indispensable important component of an automatic driving vehicle as an all-weather all-day sensor.

For efficient detection of objects, the following can generally be used: on the basis of millimeter wave radar hardware, the detection performance of a target is improved by effectively combining a more effective radar signal processing technology and a radar waveform design method; and secondly, under the condition that the scale of a receiving and transmitting channel is limited, the virtual caliber is expanded by adopting a sparse array and a Multiple Input Multiple Output (MIMO) technology so as to improve the receiving and transmitting gain.

However, it is difficult to achieve the effect of increasing the field angle FOV while increasing the transmission/reception gain.

Disclosure of Invention

In view of this, embodiments of the present invention provide a target tracking method and apparatus for a binary phase modulation array radar, so as to solve the problem in the prior art that increasing the transmit-receive gain and expanding the FOV are contradictory.

A first aspect of an embodiment of the present invention provides a target tracking method for a binary phase modulation array radar, including:

receiving v sum beams and v difference beams which are spatially synthesized and arranged at intervals by u transmitting signals, wherein the u transmitting signals are transmitted by u transmitting antennas in a mode of alternating in the same direction and in the opposite direction, and the u transmitting antennas correspond to the u transmitting signals one by one;

obtaining a target parameter of each moving target in k moving targets according to the v sum beams and the v difference beams, wherein u, v and k are positive integers;

and tracking and filtering the target parameters of each moving target, and determining the motion track of each moving target.

A second aspect of an embodiment of the present invention provides a target tracking apparatus for a binary phase modulation array radar, including:

a receiving module, configured to spatially synthesize v sum beams and v difference beams arranged at intervals by u transmit signals, where the u transmit signals are transmitted by u transmit antennas in a manner of alternating in a same direction and in a reverse direction, and the u transmit antennas correspond to the u transmit signals one to one;

the target parameter determining module is used for obtaining a target parameter of each moving target in k moving targets according to the v sum beams and the v difference beams, wherein u, v and k are positive integers;

and the motion track determining module is used for tracking and filtering the target parameters of each moving target and determining the motion track of each moving target.

A third aspect of embodiments of the present invention provides a terminal device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, the processor implementing the steps of the target tracking method of the binary phase modulation array radar according to any one of the above items when executing the computer program.

A fourth aspect of embodiments of the present invention provides a computer-readable storage medium storing a computer program which, when executed by a processor, implements the steps of the target tracking method for a binary phase modulation array radar as described in any one of the above.

Compared with the prior art, the embodiment of the invention has the following beneficial effects:

the method comprises the steps of firstly receiving v sum beams and v difference beams which are formed by synthesizing u transmitting signals in space and are arranged at intervals, wherein the u transmitting signals are transmitted by u transmitting antennas in a mode of equidirectional and opposite alternation, and the u transmitting antennas correspond to the u transmitting signals one by one; then obtaining a target parameter of each moving target in the k moving targets according to the v sum beams and the v difference beams; and then tracking and filtering the target parameters of each moving target to determine the motion track of each moving target. The invention realizes the beam forming by the binary phase modulation idea that two paths of transmitting signals transmit signals in an in-phase and reverse-phase alternating mode, improves the peak gain by using the sum beam and expands the beam broadband by using the difference beam, and achieves the effect of simultaneously improving the gain and the FOV under the condition of limited receiving and transmitting channel scale.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic flow chart illustrating an implementation of a target tracking method for a binary phase modulation array radar according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of an arrangement of two-transmitter and four-receiver radar arrays according to an embodiment of the present invention;

FIG. 3 is a schematic diagram of an 8-way virtual receive array in an embodiment of the present invention;

FIG. 4 is a flowchart illustrating an implementation of the refinement step of S102 in the embodiment of the present invention;

FIG. 5 is a timing diagram of a binary phase modulated transmit waveform in an embodiment of the present invention;

FIG. 6 is a flowchart illustrating an implementation of the refinement step of S402 in the embodiment of the present invention;

FIG. 7 is a schematic diagram of a flow chart of implementing the refinement step of S403 in the embodiment of the present invention;

FIG. 8 is a flowchart illustrating an implementation of the refinement step of S404 in the embodiment of the present invention;

FIG. 9 is a flowchart illustrating an implementation of the refinement step of S405 in the embodiment of the present invention;

FIG. 10 is a schematic diagram of a flow chart of implementing the refinement step of S901 in the embodiment of the present invention;

FIG. 11 is a flowchart illustrating an implementation of the refinement step of S902 in the embodiment of the present invention;

FIG. 12 is a schematic diagram of an implementation flow of a step before S101 in the embodiment of the present invention;

FIG. 13 is a schematic diagram of initial phase correspondence of two transmitted signals in an embodiment of the present invention;

FIG. 14 is a schematic diagram comparing binary phase modulated radar beams in an embodiment of the present invention;

fig. 15 is a schematic structural diagram of a target tracking apparatus of a binary phase modulation array radar according to an embodiment of the present invention;

fig. 16 is a schematic diagram of a terminal device according to an embodiment of the present invention.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

The miniaturization, low cost, long distance, large field of view (fov), high resolution, and multiple functions of the millimeter wave radar are the development trends of the millimeter wave radar, and are several aspects of competition among various large millimeter wave radar manufacturers.

Generally, after the millimeter wave radar hardware scheme is determined, the size of a transceiver antenna channel, the configuration of waveform parameters, the storage space, the processing capacity and the like are determined accordingly, and the technical indexes of the millimeter wave radar are closely related to the system parameters. In order to improve the angular resolution, a sparse array and a Multiple Input Multiple Output (MIMO) technology may be generally used to expand the virtual aperture under the condition that the size of a transceiving channel is limited, and in order to improve the range of action, a beamforming manner may be used to improve the transceiving gain, but the conventional beamforming is at the cost of sacrificing the beamwidth and reducing the effective FOV. Based on the problem, the application provides a target tracking method of a binary phase modulation array radar.

In order to explain the technical means of the present invention, the following description will be given by way of specific examples.

Fig. 1 is a schematic flow chart illustrating an implementation process of a target tracking method for a binary phase modulation array radar according to an embodiment of the present invention. As shown in fig. 1, a target tracking method of a binary phase modulation array radar of this embodiment includes:

step S101: receiving v sum beams and v difference beams which are spatially synthesized and arranged at intervals by u transmitting signals, wherein the u transmitting signals are transmitted by u transmitting antennas in a mode of alternating in the same direction and in the opposite direction, and the u transmitting antennas correspond to the u transmitting signals one by one;

step S102: obtaining a target parameter of each moving target in k moving targets according to the v sum beams and the v difference beams, wherein u, v and k are positive integers;

step S103: and tracking and filtering the target parameters of each moving target, and determining the motion track of each moving target.

In one embodiment, the basic idea of the present application using binary phase modulation is based on an optimally designed antenna array. The array radar works in a multi-transmission multi-reception (MIMO) mode, u transmitting signals transmit in a mode of in-phase and reverse alternation, and v sum beams and v difference beams are formed in a spatial synthesis mode, so that the aims of improving gain and expanding FOV are fulfilled. Wherein u, v and k are integers more than 1.

Further, the present application describes a two-transmit, four-receive array radar system in conjunction with fig. 2 and 3. As shown in fig. 2, the two-transmit four-receive array radar system includes two transmit antennas Tx1 and Tx2, and four receive antennas Rx1, Rx2, Rx3, and Rx 4. Assume that the spacing between two transmitting antennas Tx1 and Tx2 is λ/2 and the spacing between every two adjacent receiving antennas is λ, i.e. the spacing between the receiving antennas Rx1 and Rx2 is λ, the spacing between the receiving antennas Rx2 and Rx3 is λ, and the spacing between the receiving antennas Rx3 and Rx4 is λ. The advantage of this array arrangement is that two transmit signals formed by the two transmit antennas can be combined to form a signal with the least null depression. It should be noted that improper arrangement of the two transmit antenna arrays may cause more synthesized beam nulls, which is not favorable for target detection.

As shown in fig. 3, when the two-transmit, four-receive array radar operates in the multi-transmit multi-receive mode, eight virtual receive arrays are formed, including a receive antenna Rx1, a receive antenna Rx1', a receive antenna Rx2, a receive antenna Rx2', a receive antenna Rx3, a receive antenna Rx3', a receive antenna Rx4, and a receive antenna Rx 4'.

Specifically, taking the two-transmit four-receive array radar shown in fig. 2 as an example, two transmit antennas Tx1 and Tx2 transmit two transmit signals in a co-directional and anti-directional alternating manner, then receive four sum beams and four difference beams of the two transmit signals arranged at intervals in a space synthesis manner, and then determine the motion trajectory of each of the obtained multiple moving targets according to the four sum beams and the four difference beams.

The method comprises the steps of firstly receiving v sum beams and v difference beams which are formed by synthesizing u transmitting signals in space and are arranged at intervals, wherein the u transmitting signals are transmitted by u transmitting antennas in a mode of equidirectional and opposite alternation, and the u transmitting antennas correspond to the u transmitting signals one by one; then obtaining a target parameter of each moving target in the k moving targets according to the v sum beams and the v difference beams; and then tracking and filtering the target parameters of each moving target to determine the motion track of each moving target. The invention realizes the beam forming by the binary phase modulation idea that two paths of transmitting signals transmit signals in an in-phase and reverse-phase alternating mode, improves the peak gain by using sum beams and expands the beam width by using difference beams, and achieves the effect of simultaneously improving the gain and the FOV under the condition of limited receiving and transmitting channel scale.

Fig. 4 is a schematic flow chart of an implementation of the step of refining step S102 in the embodiment of the present invention, and as shown in fig. 4, step S102 includes:

step S401: acquiring v sum beams and v difference beams, and extracting data corresponding to each sum beam in the v sum beams and data corresponding to each difference beam in the v difference beams;

step S402: sequentially carrying out one-dimensional fast Fourier transform and two-dimensional fast Fourier transform on the data corresponding to each sum beam and the data corresponding to each difference beam to obtain two-dimensional fast Fourier transform data corresponding to each sum beam and two-dimensional fast Fourier transform data corresponding to each difference beam;

step S403: performing Doppler compensation on the two-dimensional fast Fourier transform data corresponding to each difference beam to obtain two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation;

step S404: sequentially carrying out non-coherent accumulation and constant false alarm rate detection on each two-dimensional fast Fourier transform data corresponding to the beams and the two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation to obtain k moving targets;

step S405: and respectively carrying out binary demodulation and angle-of-arrival processing on each moving target in the k moving targets to obtain a target parameter of each moving target in the k moving targets.

In an embodiment, taking two-transmit four-receive array radar as an example, two transmit antennas Tx1 and Tx2 transmit two transmit signals in a manner of alternating in the same direction and in the opposite direction, and a synthetic beam shown in fig. 5, i.e., a timing relationship of a sum beam and a difference beam, is formed in space, where Σ represents the sum beam and Δ represents the difference beam. Further, each data corresponding to the sum beam and each data corresponding to the difference beam formed are configured based on the initial phases of the two transmission antennas Tx1 and Tx 2.

Further, for two-transmitting and four-receiving array radars, the signal processing flow in the binary phase modulation mode is as follows: four-way reception data of the sum beam (i.e., four data corresponding to the sum beam) and four-way reception data of the difference beam (i.e., four data corresponding to the difference beam) are formed, respectively, where the four-way reception data of the sum beam is denoted as Σ₁、Σ₂、Σ₃、Σ₄The data size is M multiplied by N, M is the number of transmitting chirp, and N is the number of ADC sampling points; four paths of received data of the difference beam, denoted as delta₁、Δ₂、Δ₃、Δ₄The data size is M × N, M is the number of transmit chirp, and N is the number of ADC sampling points. The target parameters Of each Of the k moving targets can be obtained by performing FFT operation data, non-coherent accumulation, constant false alarm detection, binary demodulation, and angle Of arrival (DOA) processing on the data corresponding to the sum beam and the data corresponding to the difference beam.

Fig. 6 is a schematic flow chart of an implementation of the step of refining step S402 in the embodiment of the present invention, and as shown in fig. 6, step S402 includes:

step S601: performing one-dimensional fast Fourier transform on the data corresponding to each sum beam and the data corresponding to each difference beam to obtain one-dimensional fast Fourier transform data corresponding to each sum beam and one-dimensional fast Fourier transform data corresponding to each difference beam;

step S602: and performing two-dimensional fast Fourier transform on the one-dimensional fast Fourier transform data corresponding to each sum beam and the one-dimensional fast Fourier transform data corresponding to each difference beam to obtain the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam.

In one embodiment, the four data Σ corresponding to beams are₁～Σ₄Data Δ corresponding to four difference beams₁～Δ₄Performing one-dimensional Fast Fourier Transform (FFT) on each chirp data to obtain one-dimensional FFT operation data corresponding to each sum beam and one-dimensional FFT operation data corresponding to each difference beam, performing two-dimensional FFT operation on the one-dimensional FFT operation data corresponding to each sum beam and the one-dimensional FFT operation data corresponding to each difference beam after accumulating for one frame, and recording the result as four two-dimensional FFT operation data sigma corresponding to the sum beams_fft1～Σ_fft4Two-dimensional FFT operation data Delta corresponding to four difference beams_fft1～Δ_fft4. Wherein one frame includes four sum beams and four difference beams.

In another embodiment, the one-dimensional windowing is performed on the data corresponding to the beam before the one-dimensional FFT operation is performed on the beam, whereas the two-dimensional windowing is performed on the data corresponding to the beam before the two-dimensional FFT operation is performed on the beam. In particular, for four data Σ corresponding to beams₁～Σ₄Data Δ corresponding to four difference beams₁～Δ₄Sequentially performing one-dimensional windowing processing and one-dimensional FFT operation on each chirp data to obtain one-dimensional FFT operation data corresponding to each sum beam and one-dimensional FFT operation data corresponding to each difference beam, accumulating for one frame, and performing one-dimensional windowing processing and one-dimensional FFT operation on each sum beamThe one-dimensional FFT operation data corresponding to the wave beams and the one-dimensional FFT operation data corresponding to each difference wave beam are sequentially subjected to two-dimensional windowing processing and two-dimensional FFT operation, and the result is recorded as four two-dimensional FFT operation data sigma corresponding to the sum wave beams_fft1～Σ_fft4Two-dimensional FFT operation data Delta corresponding to four difference beams_fft1～Δ_fft4。

Fig. 7 is a schematic flow chart of an implementation of the refinement step of step S403 in the embodiment of the present invention, and as shown in fig. 7, step S403 includes:

step S701: acquiring a data matrix of two-dimensional fast Fourier transform data corresponding to each difference beam, and taking the row vector number L of the data matrix as the Doppler channel number L, wherein L is a positive integer;

step S702: and selecting a compensation phase corresponding to each Doppler channel in the L Doppler channels, and determining two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation according to the compensation phase corresponding to each Doppler channel.

In one embodiment, four receive data Δ for the difference beam_fft1～Δ_fft4Doppler compensation is carried out, and the compensation method comprises the following steps:

assuming that the size of each received data matrix is L multiplied by K, wherein L is the number of Doppler channels and K is the number of range channels, for the 0 th to (L/2-1) th Doppler channels, the data compensation phase in each Doppler channel isi is the ith doppler channel, i is 0 ═ L/2-1, and the result after compensation is:

for the L/2 to (L-1) th Doppler channels, the data compensation phase in each Doppler channel is phi-2 pi- (i-L)/2+ L)/L, i is the ith Doppler channel, i is L/2 to (L-1), and the compensation result is:

Δ_fft(L/2～(L-1) doppler channel) ═ Δ_fft(L/2- (L-1) Doppler channels). exp (j phi)

Fig. 8 is a schematic flow chart of an implementation of the refinement step of step S404 in the embodiment of the present invention, and as shown in fig. 8, step S404 includes:

step S801: performing non-coherent accumulation on the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation to obtain a non-coherent accumulation result;

step S802: and carrying out constant false alarm detection on the non-coherent accumulation result to obtain k moving targets.

In one embodiment, for ∑_fft1～Σ_fft4And two-dimensional FFT operation data Delta corresponding to the phase-compensated difference beam_fft1～Δ_fft4Non-coherent accumulation is carried out, gain is improved by utilizing the sum beam, the FOV is widened by utilizing the difference beam through the non-coherent accumulation of the step, the advantages of the sum beam and the difference beam are gathered together, and the non-coherent accumulation result is assumed to be a matrix A, wherein the size of the matrix A is equal to the data sigma corresponding to the four sum beams₁～Σ₄Two-dimensional FFT operation data Delta corresponding to the phase-compensated difference beam_fft1～Δ_fft4The same, i.e., L × K, matrix a is represented as follows:

further, Constant False Alarm Rate (CFAR) is a technique for determining whether a target signal exists by a radar system by discriminating between a signal output by a receiver and noise under a condition that a False Alarm probability is kept Constant. The constant false alarm detector firstly processes the input noise and then determines a threshold, compares the threshold with the input end signal, if the input end signal exceeds the threshold, the constant false alarm detector judges that the target exists, otherwise, the constant false alarm detector judges that the target does not exist. The signal is transmitted from signal source, and is affected by various interferences in the process of propagation, and after reaching the receiver, the signal is processed and output to the detector, and then the detector makes decision on the input signal according to proper criteria. The CFAR detection method based on the matrix A detects k moving targets larger than a preset detection threshold.

Fig. 9 is a schematic flow chart of an implementation of the step of refining step S405 in the embodiment of the present invention, and as shown in fig. 9, step S405 includes:

step S901: performing binary demodulation on each moving target in the k moving targets to obtain the speed and the distance of each moving target in the k moving targets;

step S902: and carrying out arrival angle processing on each moving target in the k moving targets to obtain the azimuth angle of each moving target in the k moving targets.

In one embodiment, the target parameters include speed, distance, and azimuth.

Fig. 10 is a schematic flow chart of an implementation of the step of refining step S901 in the embodiment of the present invention, and as shown in fig. 10, step S901 includes:

step S1001: acquiring coordinates of each moving target in the k moving targets in the non-coherent accumulation result, wherein the coordinates comprise an abscissa and an ordinate;

step S1002: taking the abscissa of each moving target in the k moving targets in the non-coherent accumulation result as a corresponding Doppler channel index number of each moving target, and taking the ordinate of each moving target in the k moving targets in the non-coherent accumulation result as a corresponding distance channel index number of each moving target;

step S1003: acquiring array radar speed resolution unit parameters and array radar distance resolution unit parameters;

step S1004: multiplying the Doppler channel index number corresponding to each moving target by the array radar speed resolution unit parameter to obtain the speed of each moving target;

step S1005: and multiplying the distance channel index number corresponding to each moving target by the array radar distance resolution unit parameter to obtain the distance of each moving target.

In an embodiment, for each detected moving object, the distance and the speed of the moving object may be calculated according to the position of the moving object in the a matrix, and assuming that the coordinate of a certain moving object in the a matrix is (l, m), where l is the index number of the doppler channel and m is the index number of the range channel, the speed V and the distance R of the moving object may be determined by the following formulas:

V＝l·dv

R＝m·dr

dv is a velocity resolution unit parameter of the array radar, dr is a distance resolution unit parameter of the array radar, and the dv is determined by a design parameter of the radar system.

Fig. 11 is a schematic flow chart illustrating an implementation flow of the refinement step of step S902 in the embodiment of the present invention, and as shown in fig. 11, step S902 includes:

step S1101: acquiring phase deviation between two adjacent data corresponding to the sum beam and the difference beam;

step S1102: performing phase compensation on coordinates of each moving target in the data corresponding to the v difference beams in the non-coherent accumulation result by using the phase deviation to obtain data corresponding to the v difference beams after compensation;

step S1103: calculating v data corresponding to the sum beams and the compensated v data corresponding to the difference beams, and determining the amplitude and phase information of each moving object in each virtual channel of 2v virtual channels;

step S1104: rearranging the amplitude and phase information in each virtual channel of 2v virtual channels according to the arrangement sequence of 2v virtual receiving antenna arrays formed by the array radar to obtain the rearranged amplitude and phase information of the 2v virtual channels;

step S1105: carrying out fast Fourier transform on the amplitude and phase information of the rearranged 2v virtual channels to obtain frequency spectrums corresponding to the amplitude and phase information of the rearranged 2v virtual channels;

step S1106: and selecting an azimuth angle corresponding to the peak position in the frequency spectrum, and taking the azimuth angle corresponding to the peak position as the azimuth angle of each moving target.

In an embodiment, after the speed and the distance of the moving object are solved, the azimuth angle of the moving object needs to be further solved by DOA processing. Taking two-transmitting and four-receiving array radars as an example, the principle of azimuth angle calculation is calculated by using the phase difference between 8 paths of virtual receiving channels. Firstly, the phase deviation between the sum beam and the difference beam caused by the motion of the moving target at the speed V is compensated, and if the phase deviation is theta, the data on the coordinate where the moving target is located in the four paths of received data of the difference beam is compensated:

Δ_ffti(l,m)＝Δ_ffti(l,m)·exp(-jθ)；i＝1,2,3,4

after the compensation is finished, respective phase information of the moving target in 8 virtual receiving channels is obtained, and the method comprises the following steps:

Rx_i＝Σ_ffti(l,m)+Δ_ffti(l,m)；i＝1,2,3,4

Rx_i+4＝Σ_ffti(l,m)-Δ_ffti(l,m)；i＝1,2,3,4

in the above formula, Rx_iAmplitude and phase information in the ith virtual channel for the moving object.

Further, after obtaining the amplitude and phase information of 8 virtual receiving channels, the data of the 8 virtual channels are rearranged according to the antenna array arrangement sequence to form the following sequence:

{Rx₁,Rx₅,Rx₂,Rx₆,Rx₃,Rx₇,Rx₄,Rx₈}

and performing FFT processing on the sequence to obtain frequency spectrums corresponding to the amplitude and phase information of the 8 rearranged virtual channels, determining corresponding azimuth angles according to peak positions on the frequency spectrums, completing target parameter calculation, and obtaining the speed, distance and azimuth angles of the moving target.

Fig. 12 is a schematic view of an implementation flow of steps before step S101 in the embodiment of the present invention, and as shown in fig. 12, step S101 includes:

step S1201: configuring different initial phase sequences for the u transmitting signals;

step S1202: u transmission signals configured with different initial phase sequences are transmitted.

In an embodiment, when the optimized antenna array form is selected, different initial phases are set for two paths of transmission signals corresponding to the two transmission antennas Tx1 and Tx 2:

initial phase sequence of Tx 1: {0,0,0,0,...0,0}

Initial phase sequence of Tx 2: {0, π,0, π,. 0, π }

In the radar transmission, Tx1 and Tx2 are simultaneously turned on, and the initial phase of Tx1 and the initial phase of Tx2 are arranged in the above sequence, so that data corresponding to the beam and data corresponding to the difference beam are formed as shown in fig. 13, where Σ denotes data corresponding to the beam and Δ denotes data corresponding to the difference beam.

Taking the omnidirectional transmitting and receiving directions of a single antenna array element as an example, as shown in fig. 14, compared with a conventional single transmitting antenna, the sum beam can bring higher gain, but the beam width is lost, the difference beam widens the beam width, but the gain in the normal direction is lost, or even a larger recess is formed, and if the sum beam and the difference beam are accumulated after binary phase modulation, the effects of effectively improving the gain level and expanding the beam width can be formed, that is, the FOV can be enlarged while the radar action distance is increased.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

In one embodiment, as shown in fig. 15, there is provided a target tracking apparatus of a binary phase modulation array radar, including: a receiving module 1501, a target parameter determining module 1502, and a motion trajectory determining module 1503, wherein:

a receiving module 1501, configured to receive v sum beams and v difference beams that are spatially synthesized and arranged at intervals, where u transmit signals are transmitted by u transmit antennas in a manner of alternating in the same direction and in the opposite direction, and the u transmit antennas correspond to the u transmit signals one to one;

a target parameter determining module 1502, configured to obtain a target parameter of each moving target of k moving targets according to the v sum beams and the v difference beams, where u, v, and k are positive integers;

and a motion trajectory determination module 1503, configured to perform tracking filtering on the target parameter of each moving target, and determine a motion trajectory of each moving target.

In one embodiment, the objective parameter determination module 1502 includes:

the data extraction submodule is used for acquiring v sum beams and v difference beams and extracting data corresponding to each sum beam in the v sum beams and data corresponding to each difference beam in the v difference beams;

the FFT operation sub-module is used for sequentially carrying out one-dimensional fast Fourier transform and two-dimensional fast Fourier transform on the data corresponding to each sum beam and the data corresponding to each difference beam to obtain two-dimensional fast Fourier transform data corresponding to each sum beam and two-dimensional fast Fourier transform data corresponding to each difference beam;

the phase compensation submodule is used for performing Doppler compensation on the two-dimensional fast Fourier transform data corresponding to each difference beam to obtain the two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation;

the moving target acquisition sub-module is used for sequentially carrying out non-coherent accumulation and constant false alarm detection on each two-dimensional fast Fourier transform data corresponding to the corresponding wave beam and the two-dimensional fast Fourier transform data corresponding to each difference wave beam after phase compensation to obtain k moving targets;

and the target parameter determination submodule is used for respectively carrying out binary demodulation and arrival angle processing on each moving target in the k moving targets to obtain the target parameter of each moving target in the k moving targets.

In one embodiment, the FFT operation sub-module includes:

the one-dimensional FFT operation unit is used for performing one-dimensional fast Fourier transform on each data corresponding to the sum beam and each data corresponding to the difference beam to obtain one-dimensional fast Fourier transform data corresponding to each sum beam and one-dimensional fast Fourier transform data corresponding to each difference beam;

and the two-dimensional FFT operation unit is used for carrying out two-dimensional fast Fourier transform on the one-dimensional fast Fourier transform data corresponding to each sum beam and the one-dimensional fast Fourier transform data corresponding to each difference beam to obtain the two-dimensional fast Fourier transform data corresponding to each sum beam and the two-dimensional fast Fourier transform data corresponding to each difference beam.

In one embodiment, a phase compensation sub-module includes:

a data matrix obtaining unit, configured to obtain a data matrix of two-dimensional fast fourier transform data corresponding to each difference beam, and use a row vector number L of the data matrix as a doppler channel number L, where L is a positive integer;

and the phase compensation unit is used for selecting a compensation phase corresponding to each Doppler channel in the L Doppler channels and determining two-dimensional fast Fourier transform data corresponding to each difference beam after phase compensation according to the compensation phase corresponding to each Doppler channel.

In one embodiment, the moving object acquisition sub-module includes:

the non-coherent accumulation unit is used for performing non-coherent accumulation on each two-dimensional fast Fourier transform data corresponding to the corresponding wave beam and the two-dimensional fast Fourier transform data corresponding to each difference wave beam after phase compensation to obtain a non-coherent accumulation result;

and the CFAR detection unit is used for carrying out constant false alarm detection on the non-coherent accumulation result to obtain k moving targets.

In one embodiment, the target parameters include speed, distance, and azimuth;

a target parameter determination submodule comprising:

the binary demodulation unit is used for carrying out binary demodulation on each moving target in the k moving targets to obtain the speed and the distance of each moving target in the k moving targets;

and the DOA processing unit is used for carrying out arrival angle processing on each moving target in the k moving targets to obtain the azimuth angle of each moving target in the k moving targets.

In one embodiment, a binary demodulation unit includes:

the coordinate acquisition subunit is used for acquiring coordinates of each of the k moving targets in the non-coherent accumulation result, wherein the coordinates comprise an abscissa and an ordinate;

the index number determining subunit is used for taking the abscissa of each moving target in the k moving targets in the non-coherent accumulation result as the Doppler channel index number corresponding to each moving target, and taking the ordinate of each moving target in the k moving targets in the non-coherent accumulation result as the distance channel index number corresponding to each moving target;

the radar parameter acquisition subunit is used for acquiring array radar speed resolution unit parameters and array radar distance resolution unit parameters;

the velocity calculation subunit is used for multiplying the Doppler channel index number corresponding to each moving target by the array radar velocity resolution unit parameter to obtain the velocity of each moving target;

and the distance calculation subunit is used for multiplying the distance channel index number corresponding to each moving target by the array radar distance resolution unit parameter to obtain the distance of each moving target.

In one embodiment, a DOA processing unit includes:

the phase deviation acquiring subunit is used for acquiring the phase deviation between two adjacent data corresponding to the sum beam and the difference beam;

the phase compensation subunit is used for performing phase compensation on coordinates of each moving target in the data corresponding to the v difference beams in the non-coherent accumulation result by using the phase deviation to obtain data corresponding to the v difference beams after compensation;

the virtual channel parameter determining subunit is used for calculating v data corresponding to the sum beams and the compensated v data corresponding to the difference beams, and determining amplitude and phase information of each moving object in each virtual channel of 2v virtual channels;

the data arrangement subunit is used for rearranging the amplitude and phase information in each virtual channel of the 2v virtual channels according to the arrangement sequence of the 2v virtual receiving antenna arrays formed by the array radar to obtain the rearranged amplitude and phase information of the 2v virtual channels;

the FFT processing subunit is used for carrying out fast Fourier transform on the amplitude and phase information of the rearranged 2v virtual channels to obtain frequency spectrums corresponding to the amplitude and phase information of the rearranged 2v virtual channels;

and the azimuth angle determining subunit is used for selecting an azimuth angle corresponding to the peak position in the frequency spectrum, and taking the azimuth angle corresponding to the peak position as the azimuth angle of each moving target.

In an embodiment, before receiving module 1501, the method further includes:

the initial phase configuration module is used for configuring different initial phase sequences for the u transmitting signals;

and the signal transmitting module is used for transmitting u transmitting signals with different initial phase sequences.

Fig. 16 is a schematic diagram of a terminal device according to an embodiment of the present invention. As shown in fig. 16, the terminal device 16 of this embodiment includes: a processor 1601, a memory 1602, and a computer program 1603 stored in the memory 1602 and operable on the processor 1601. The processor 1601, when executing the computer program 1603, implements the steps in each of the above described embodiments of the target tracking method for binary phase modulation array radar, such as steps S101 to S103 shown in fig. 1. Alternatively, the processor 1601 may implement the functions of the modules/units in the above-described apparatus embodiments, for example, the functions of the modules 1501 to 1503 shown in fig. 15, when executing the computer program 1603.

Illustratively, the computer programs 1603 may be divided into one or more modules/units, which are stored in the memory 1602 and executed by the processor 1601 to implement the present invention. One or more modules/units may be a series of computer program instruction segments capable of performing specific functions, which are used to describe the execution of the computer program 1603 in the terminal device 16. For example, the computer program 1603 may be divided into a receiving module, a target parameter determining module and a motion trajectory determining module, each module having the following specific functions:

a receiving module, configured to receive v sum beams and v difference beams that are spatially synthesized and arranged at intervals by u transmit signals, where the u transmit signals are transmitted by u transmit antennas in a manner of alternating in the same direction and in the opposite direction, and the u transmit antennas correspond to the u transmit signals one to one;

the target parameter determining module is used for obtaining a target parameter of each moving target in k moving targets according to the v sum beams and the v difference beams, wherein u, v and k are positive integers;

and the motion track determining module is used for tracking and filtering the target parameters of each moving target and determining the motion track of each moving target.

The terminal device 16 may be a computing device such as a desktop computer, a notebook, a palm top computer, and a cloud server. The 16 terminal device may include, but is not limited to, a processor 1601, a memory 1602. Those skilled in the art will appreciate that fig. 16 is merely an example of a terminal device and is not limiting of terminal devices and may include more or fewer components than shown, or some components may be combined, or different components, e.g., a terminal device may also include input output devices, network access devices, buses, etc.

The Processor 1601 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The storage 1602 may be an internal storage unit of the terminal device 16, such as a hard disk or a memory of the terminal device 16. The memory 1602 may also be an external storage device of the terminal device 16, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), or the like provided on the terminal device 16. Further, memory 1602 may also include both internal and external storage for terminal device 16. The memory 1602 is used for storing computer programs and other programs and data required by the terminal device. The memory 1602 may also be used to temporarily store data that has been output or is to be output.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules, so as to perform all or part of the functions described above. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the above embodiments, the descriptions of the respective embodiments have respective emphasis, and reference may be made to the related descriptions of other embodiments for parts that are not described or illustrated in a certain embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiments provided in the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other ways. For example, the above-described embodiments of the apparatus/terminal device are merely illustrative, and for example, a module or a unit may be divided into only one logical function, and may be implemented in other ways, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

Units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit.

The integrated modules/units, if implemented in the form of software functional units and sold or used as separate products, may be stored in a computer readable storage medium. Based on such understanding, all or part of the flow in the method according to the embodiments of the present invention may also be implemented by a computer program to instruct related hardware, where the computer program may be stored in a computer readable storage medium, and when the computer program is executed by a processor, the computer program may implement the steps of the embodiments of the method. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include: any entity or device capable of carrying computer program code, recording medium, U.S. disk, removable hard disk, magnetic disk, optical disk, computer Memory, Read-Only Memory (ROM), Random Access Memory (RAM), electrical carrier wave signals, telecommunications signals, software distribution media, and the like. It should be noted that the computer readable medium may contain other components which may be suitably increased or decreased as required by legislation and patent practice in jurisdictions, for example, in some jurisdictions, in accordance with legislation and patent practice, the computer readable medium does not include electrical carrier signals and telecommunications signals.

The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present invention, and are intended to be included within the scope of the present invention.