Target recognition method, device and storage medium

Abstract

This application relates to the field of radar technology and discloses a target recognition method: acquiring a first digital beamforming (DBF) pattern of the target to be identified, wherein the first DBF pattern is obtained by performing DBF angle measurement on the radar target echo signal; determining multiple first amplitude maxima points; acquiring i angle values ​​corresponding to the first i first amplitude maxima points in descending order; and selecting the angle value A of the current target to be identified from the i angle values. k And filter out A from the radar target echo signal k The corresponding signal is used to obtain the residual signal component; the second DBF pattern corresponding to the residual signal component is determined; in the second DBF pattern, if A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k Furthermore, if the (i-1)th angle value is not the angle value corresponding to the (i-1)th second maximum amplitude point, then the current target to be identified is determined to be the real target. Through the above method, this application achieves accurate identification of the real target based on the radar target echo signal.

Description

Technical Field

[0001] This application relates to the field of radar technology, specifically to a target identification method, device, and storage medium. Background Technology

[0002] Due to its advantages such as high stability and immunity to adverse weather conditions, radar (e.g., automotive millimeter-wave radar) is widely used in the field of autonomous driving. As a crucial component of driverless vehicles, the market demand for inexpensive yet high-performance radar is growing. High-performance radar refers to its high accuracy in target detection and wide applicability.

[0003] To ensure low radar costs, it's typically necessary to reduce the number of antenna elements and related components. However, reducing these elements leads to a decrease in radar performance. For example, in scenarios with significant clutter, noise, and interference (such as complex urban traffic environments), the accuracy of target detection and identification decreases. Therefore, improving the accuracy of target identification for radars with simplified structures is a pressing issue that needs to be addressed. Summary of the Invention

[0004] In view of the above problems, embodiments of this application provide a target identification method, device and storage medium to solve the problem of low accuracy in target identification by radar with simplified structure in the prior art.

[0005] According to one aspect of the embodiments of this application, a target identification method is provided, the method comprising: acquiring a first digital beamforming (DBF) pattern of a target to be identified, wherein the first DBF pattern is obtained by performing DBF angle measurement on a radar target echo signal; determining a plurality of first amplitude maxima points based on all amplitude points of the first DBF pattern, wherein each first amplitude maxima point is an amplitude point among all amplitude points of the first DBF pattern whose amplitude is greater than the adjacent left and right amplitudes; acquiring i angle values ​​corresponding to the first i first amplitude maxima points in descending order of the first amplitude maxima points, wherein the first i first amplitude maxima points are points corresponding to the target to be identified, i is a positive integer, i is greater than 1; and selecting an angle value A from the i angle values. k The A k The corresponding target is the current target to be identified, and the A target is filtered out from the radar target echo signal. k The corresponding signal is used to obtain the residual signal component, where k is a positive integer and k≤i; the second DBF pattern corresponding to the residual signal component is determined; in the second DBF pattern, if the A kThe angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second amplitude maxima points, then the current target to be identified is determined to be a real target. The amplitude minima point is the amplitude point in the second DBF direction map whose amplitude is smaller than the adjacent left and right amplitudes, and the second amplitude maxima point is the amplitude point in the second DBF direction map whose amplitude is larger than the adjacent left and right amplitudes.

[0006] In one alternative approach, the radar target echo signal is a signal reflected back from an object in the detection area after the radar array emits electromagnetic waves into the detection area, and the step of filtering out A from the radar target echo signal... k The corresponding signal is used to obtain the residual signal component, including: according to the A k Determine the theoretical signal Y of the target to be identified under the detection of the radar array. k According to the first DBF pattern, A k The corresponding numerical value and the Y k Determine the Y k The estimated signal component S in the first DBF pattern k Wherein, the value is a complex number; the S is filtered out from the radar target echo signal. k The residual signal components are obtained.

[0007] In one alternative approach, if the A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second amplitude maxima points, then the current target to be identified is determined to be a real target, including: determining multiple second amplitude maxima points and multiple amplitude minima points based on all amplitudes of the second DBF pattern; sorting the multiple second amplitude maxima points from largest to smallest to obtain the first i-1 second amplitude maxima points; if the A k The angle value corresponding to one of the multiple amplitude minimum points, and excluding A among the i angle values. k In addition, if the remaining i-1 angle values ​​do not belong to the angle values ​​corresponding to the first i-1 second amplitude maxima points, then the current target to be identified is determined to be the real target.

[0008] In one alternative approach, i is 3.

[0009] In an alternative embodiment, the method further includes: in the second DBF pattern, if the Ak Angle values ​​that do not correspond to the minimum amplitude point, or excluding A from the i angle values. k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second maximum amplitude points, then select an angle value A that has not been selected from the i angle values. k ; Proceed to the step of filtering out A from the radar target echo signal k The corresponding signal is used to obtain the residual signal component.

[0010] In an alternative embodiment, prior to acquiring the first DBF pattern of the target to be identified, the method further includes: acquiring the radar target echo signal; performing Fourier transforms on the radar target echo signal in the range and velocity dimensions to obtain range-Doppler RD spectrum data; and acquiring the original target array signal S of the target range and target velocity from the RD spectrum data. origin The step of obtaining the first DBF pattern of the target to be identified includes: [the step of obtaining the first DBF pattern of the target to be identified] on the S... origin DBF angle measurement is performed to obtain the first DBF pattern.

[0011] In one alternative approach, the method based on A k Determine the theoretical signal Y of the target to be identified under the detection of the radar array. k This includes: according to the first preset parameter, the A k The radar array arrangement, the elevation angle of the actual target, and the wavelength exponent of the radar target echo signal are used to calculate the theoretical signal Y, using a preset value as the base and the exponent value as the exponent. k .

[0012] In one alternative approach, the A according to the first DBF pattern k The corresponding numerical value and the Y k Determine the Y k The estimated signal component S in the first DBF pattern k This includes: through formula S k =Y k *S map (A k The S was calculated. k , of which S map (A k ) represents the stated value.

[0013] According to another aspect of the embodiments of this application, a target recognition device is provided, comprising: a first acquisition module, configured to acquire a first digital beamforming (DBF) pattern of a target to be identified, wherein the first DBF pattern is obtained by performing DBF angle measurement on radar target echo signals; a first determination module, configured to determine a plurality of first amplitude maxima points based on all amplitude points of the first DBF pattern, wherein each first amplitude maxima point is an amplitude point among all amplitude points of the first DBF pattern whose amplitude is greater than the adjacent left and right amplitudes; a second acquisition module, configured to acquire i angle values ​​corresponding to the first i first amplitude maxima points in descending order of the first amplitude maxima points among the plurality of first amplitude maxima points, wherein the first i first amplitude maxima points are points corresponding to the target to be identified, i is a positive integer, i is greater than 1; and a filtering module, configured to select angle value A from the i angle values. k The A k The corresponding target is the current target to be identified, and the A target is filtered out from the radar target echo signal. k The corresponding signal is used to obtain the residual signal component, where k is a positive integer and k≤i; the second determining module is used to determine the second DBF pattern corresponding to the residual signal component; the third determining module is used to determine, in the second DBF pattern, if the A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second amplitude maxima points, then the current target to be identified is determined to be a real target. The amplitude minima point is the amplitude point in the second DBF direction map whose amplitude is smaller than the adjacent left and right amplitudes, and the second amplitude maxima point is the amplitude point in the second DBF direction map whose amplitude is larger than the adjacent left and right amplitudes.

[0014] According to another aspect of the embodiments of this application, a target recognition device is provided, including: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other through the communication bus; the memory is used to store executable instructions, which cause the processor to perform the target recognition method as described above.

[0015] According to another aspect of the embodiments of this application, a computer-readable storage medium is provided, wherein executable instructions are stored in the storage medium, and the executable instructions perform operations such as the target recognition method described above when executed.

[0016] Due to the original signal S of the target array origin To obtain the actual signal, if A k If the angle value corresponds to the actual target, then through A...k The theoretical signal Y obtained by calculation k The signal value is close to its actual value. Therefore, in this embodiment of the application, the original signal S of the target array is filtered out. origin Angle value A in k The corresponding theoretical signal Y k The signal component estimate S corresponding to the first DBF pattern k Then, A can be filtered out. k The corresponding signal component estimate S k The second DBF pattern obtained later accurately determined A. k Is it the angle value corresponding to the actual target?

[0017] The above description is merely an overview of the technical solutions of the embodiments of this application. In order to better understand the technical means of the embodiments of this application and to implement them in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the embodiments of this application more obvious and understandable, specific implementation methods of this application are described below. Attached Figure Description

[0018] The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0019] Figure 1 A flowchart illustrating the target identification method provided in an embodiment of this application is shown;

[0020] Figure 2 A schematic diagram of the radar array in the simulation experiment provided in the embodiments of this application is shown;

[0021] Figure 3 This illustration shows a first DBF pattern and a DBF pattern after filtering out the theoretical signal of the real target, as provided in an embodiment of this application.

[0022] Figure 4 This illustration shows another first DBF pattern provided by an embodiment of the present application and a schematic diagram of the DBF pattern after filtering out the theoretical signal of the false peak target located to the left of the real target;

[0023] Figure 5 This illustration shows another first DBF pattern provided by an embodiment of the present application and a schematic diagram of the DBF pattern after filtering out the theoretical signal of the false peak target located to the right of the real target;

[0024] Figure 6 A schematic diagram of the target recognition device provided in an embodiment of this application is shown;

[0025] Figure 7A schematic diagram of the target recognition device provided in an embodiment of this application is shown. Detailed Implementation

[0026] Exemplary embodiments of the present application will now be described in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be implemented in various forms and should not be limited to the embodiments set forth herein.

[0027] Radar target echo refers to the signal reflected back from the surface of a target object after the electromagnetic waves emitted by the radar reach it. Typically, different objects have different speed (relative to the radar), distance (distance to the radar), and angle (angle and position relative to the radar). Therefore, the signals reflected back from the surfaces of individual objects will also differ. Based on this, target objects can be identified through radar target echoes. For example, in an urban traffic environment, if vehicles are the target of interest and buildings are not, after the radar emits electromagnetic waves into the detection area, the waves will reach multiple objects, including vehicles and buildings. The radar target echo signal will then include signals reflected back from these objects. Because the reflection characteristics, speed, distance, and angle information of vehicles and buildings are not entirely the same, vehicles can be identified from the radar target echo.

[0028] Digital Beam Forming (DBF) technology can weight and sum the echo signals received by a radar array to form a beam in a specific direction, thereby achieving the reception and enhancement of the desired signal. The specific direction refers to the direction of the target of interest (i.e., the direction and angle of the actual target). Therefore, by using the radar target echo signal to perform DBF angle measurement and obtain the DBF pattern, the angle value corresponding to the actual target can usually be determined based on the amplitude in the DBF pattern, thus enabling further localization of the actual target. In the DBF pattern, the horizontal axis represents the azimuth angle; the vertical axis represents the amplitude and phase results, which are complex numbers. Taking the modulus of the obtained complex amplitude and phase results yields the amplitude, which represents the signal strength in that direction.

[0029] It should be noted that, for ease of analysis, in the embodiments of this application, the amplitude of the amplitude point in the first DBF radiation pattern and the second DBF radiation pattern is the result of taking the modulus of the complex amplitude and phase result in the DBF radiation pattern obtained by DBF technology and converting the modulus value into dB units.

[0030] The inventors of this application discovered in their research that if the angle value corresponding to the maximum amplitude (i.e. peak value) in the DBF pattern is directly determined as the angle value of the real target, there will be a certain error. This is because the radar itself will have a certain error. Therefore, the peak value in the DBF pattern determined based on the radar target echo signal may be a false peak value caused by side lobes and grating lobes. That is, the peak value is not the peak value corresponding to the real target signal.

[0031] Based on the above, this application proposes a target identification method. In this method, a first DBF radiation pattern is obtained by performing DBF angle measurement on the radar target echo. Based on the peak value of the first DBF radiation pattern and the corresponding angle value A, the signal corresponding to the angle value A is filtered out from the radar target echo signal to obtain the residual signal component. Then, DBF angle measurement is performed on the residual signal component to obtain a second DBF radiation pattern. Based on the second DBF radiation pattern, it can be accurately determined whether the angle value A is the angle value of the real target.

[0032] Figure 1 A flowchart of a target identification method provided in an embodiment of this application is shown. This method is executed by a terminal device. The terminal device may be a radar or a device communicatively connected to a radar to acquire radar detection signals. The terminal device may include one or more processors. These processors may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of this invention; no limitation is made herein. The one or more processors included in the terminal device may be processors of the same type, such as one or more CPUs; or they may be processors of different types, such as one or more CPUs and one or more ASICs; no limitation is made herein. Figure 1 As shown, the method includes the following steps:

[0033] Step 110: Obtain the first DBF pattern of the target to be identified, wherein the first DBF pattern is obtained by performing DBF angle measurement on the radar target echo signal.

[0034] As mentioned earlier, the DBF radiation pattern can typically be obtained by using radar target echo signals for DBF angle measurement. In some embodiments, if it is not necessary to identify all objects within the radar detection range, but only target objects (e.g., objects at a set target distance and target velocity), then before performing step 110, steps a1 to a3 can be performed first to obtain the original target array signal S containing only the target objects. origin Based on S origin Generate the first DBF pattern.

[0035] Step a1: Acquire radar target echo signal.

[0036] Among them, the radar target echo signal is the signal reflected back by objects in the detection area after the radar array emits electromagnetic waves into the detection area.

[0037] Step a2: Perform Fourier transforms of the radar target echo signal in the range and velocity dimensions to obtain range-Doppler RD spectrum data.

[0038] The Fourier transform is a linear integral transform used to transform a function (usually referred to as a "signal") between the time and frequency domains. The inventors of this application found that most existing methods for filtering radar echo signals primarily target non-interesting signals such as interference and clutter, and largely utilize the Doppler effect of the echo signal. Research on filtering radar array signals obtained through two-dimensional (range and velocity dimensions) Fourier transforms is relatively limited. In the embodiments of this application, radar array signals obtained through two-dimensional Fourier transforms are used for filtering, and the filtered signal is used to accurately identify targets.

[0039] The Doppler effect refers to the frequency change phenomenon caused by the relative motion between the transmitter and receiver. It can be divided into stationary receivers and moving transmitters, as well as moving receivers and stationary transmitters, and has applications in radar, sonar, astronomy and optics.

[0040] In this step, after performing a range-dimensional Fourier transform on the radar target echo signal, a velocity-dimensional Fourier transform is then performed to obtain range-Doppler (RD) data. The RD spectrum data includes the distance information of each object within the radar's detection range from the radar, as well as the velocity information of each object relative to the radar.

[0041] Step a3: Obtain the original target array signal S containing the target distance and target velocity from the RD spectrum data. origin .

[0042] Among them, the target distance and target speed can be set as needed. Specifically, if you want to focus on or identify a target object at a certain distance and speed, then set that distance and speed as the target distance and target speed.

[0043] In some embodiments, target objects in terms of target distance and target velocity in the RD spectrum data are detected by constant false alarm rate (CFAR) detection to obtain the original target array signal S. originCFAR detection, while maintaining a constant false alarm probability, judges the signal and noise output by the receiver to determine whether a target signal exists. The input is the result obtained by Fourier transform of the radar echo signal in the range and velocity dimensions, and the output is the detected target result.

[0044] In step 110, the original signal S of the target array is processed. origin By performing DBF angle measurement, the first DBF radiation pattern can be obtained. The first DBF radiation pattern has a specification of 1*M, where M is the number of angle search points for DBF angle measurement, which can be set as needed, such as 300, 500, 900, etc.

[0045] Step 120: Based on all amplitude points of the first DBF pattern, determine multiple first amplitude maxima points, wherein each first amplitude maxima point is an amplitude point among all amplitude points of the first DBF pattern whose amplitude is greater than the adjacent left and right amplitudes.

[0046] In this design, the first DBF pattern is continuous (beam shape is continuous). Within the first DBF pattern, if the amplitude of a point is greater than the amplitudes of its adjacent points to its left and right, then that point is considered the first amplitude maximum. From the perspective of beam shape, the crest of each wave in the first DBF pattern is also a first amplitude maximum. It can be understood that multiple first amplitude maximum points include the point with the maximum amplitude in the first DBF pattern.

[0047] Step 130: According to the order of the first amplitude maxima among the multiple first amplitude maxima points from largest to smallest, obtain the i angle values ​​corresponding to the first i first amplitude maxima points, where i is a positive integer and i is greater than 1.

[0048] As mentioned earlier, since DBF technology can form a beam in a specific direction to receive and enhance the desired signal, in this step, after finding the i angle values ​​corresponding to the first i amplitude maxima, we can further determine whether there is an angle value corresponding to the real target among the i angle values. Here, i can be set as needed, for example, i = 2, 3, etc.

[0049] If the false peak is caused by a grating lobe, it will have a characteristic of being symmetrical about the target. That is, there will usually be two false peaks, distributed on the left and right sides of the target respectively. Therefore, in this embodiment, considering the real target and one side lobe or grating lobe false target within the left and right angle search range, i is preferably set to 3.

[0050] Step 140: Select angle value A from the i angle values. k A k The corresponding target is the current target to be identified, and A is filtered out from the radar target echo signal.k The corresponding signal is used to obtain the residual signal component, where k is a positive integer and k≤i.

[0051] Wherein, if the target to be identified is a real target, i.e., A k If the angle value corresponds to the actual target, then in this step, A is filtered out from the radar target echo signal. k After the corresponding signal is received, the signals corresponding to false targets caused by side lobes and grating lobes will be filtered out as well. Therefore, in this step, A is filtered out from the radar target echo signal. k After obtaining the corresponding signal, A can be further analyzed based on the obtained residual signal components. k Is it the angle value corresponding to the actual target?

[0052] In some embodiments, in order to improve the accuracy of the obtained residual signal components, the residual signal components are determined by the following steps b1 to b3.

[0053] Step b1: According to A k Determine the theoretical signal Y of the target under radar array detection. k .

[0054] Among these, those skilled in the art can calculate Y using relevant formulas as needed. k Or, relevant simulation experiments can be conducted to obtain Y. k .

[0055] Step b2: Based on A in the first DBF pattern k The corresponding values ​​and Y k Determine Y k Signal component estimate S in the first DBF pattern k , where the value is a complex number.

[0056] Among them, the signal component estimate S k For A k The corresponding theoretical signal Y k The estimated value corresponding to the first DBF pattern. Those skilled in the art can calculate S using relevant formulas as needed. k Or, relevant simulation experiments can be conducted to obtain S. k .

[0057] In some embodiments, in order to improve the obtained S k The accuracy is determined using the formula S. k =Y k *S map (A k S was calculated. k , of which S kThe specification is 1*N, where N is the total number of radar array elements that emit electromagnetic waves into the detection area, and S... map (A k ) represents A in the first DBF pattern. k The corresponding value, where the value is in complex form, is also called A in the first DBF pattern. k The corresponding amplitude and phase results. As mentioned earlier, in the first DBF pattern, A k The corresponding amplitude is the result of taking the modulus of the complex number and converting the modulus to dB units.

[0058] Step b3: Filter out S from radar target echo signals k The residual signal components are obtained.

[0059] Among them, filtering out S from radar target echo signals k The residual signal component S can then be obtained. k ', residual signal component S k ' represents the original signal S of the target array. origin A filter k After estimating the corresponding theoretical signal components, the remaining signal components are obtained. In this step, the formula can be used... S was calculated k '.

[0060] Step 150: Determine the second DBF pattern corresponding to the residual signal components.

[0061] The second DBF pattern can be obtained by performing DBF angle measurement on the residual signal components.

[0062] Step 160: In the second DBF pattern, if A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second amplitude maxima points, then the current target to be identified is determined to be a real target. Among them, the amplitude minima point is the amplitude point in the second DBF direction pattern whose amplitude is less than the adjacent left and right amplitudes, and the second amplitude maxima point is the amplitude point in the second DBF direction pattern whose amplitude is greater than the adjacent left and right amplitudes.

[0063] Due to the original signal S of the target array origin To obtain the actual signal, if A k If the angle value corresponds to the actual target, then through A... k The theoretical signal Y obtained by calculation k The signal value is close to its actual value. Therefore, in this embodiment of the application, the original signal S of the target array is filtered out. origin Angle value A ink The corresponding theoretical signal Y k The signal component estimate S corresponding to the first DBF pattern k Then, DBF angle measurement is performed on the residual signal components to obtain the second DBF pattern. Based on the second DBF pattern, A can be determined. k The corresponding theoretical signal component estimate S k Whether it is filtered out can further accurately determine A. k Is it the angle value corresponding to the actual target? Specifically, it can be sorted by the magnitude of all amplitude points in the second DBF radiation pattern based on the amplitude points corresponding to each of the i angle values ​​in the i angle values. If A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second maximum amplitude points, then A can be determined. k For the angle values ​​corresponding to the real target, among the i angle values, excluding A... k The i-1 outer angle values ​​are the angle values ​​of the false targets caused by the side lobes and grating lobes.

[0064] If the false peaks are caused by grating lobes, there will be a characteristic symmetrical about the target. That is, there will usually be two false peaks, distributed on the left and right sides of the target respectively. Based on this, in order to further improve the accuracy of target recognition, in Figure 1 Based on the provided embodiments, in this application embodiment, i is 3, and step 160 includes:

[0065] Step c1: Based on all the amplitudes of the second DBF pattern, determine multiple second amplitude maxima and multiple amplitude minima.

[0066] This step is similar to step 120, so the implementation method of this step can refer to step 120, and will not be repeated here.

[0067] Step c2: Sort the multiple second amplitude maxima points from largest to smallest, and obtain the first i-1 second amplitude maxima points.

[0068] Step c3: If A k The angle value corresponding to one of the multiple amplitude minima, and among the i angle values ​​excluding A. k In addition, if the remaining i-1 angle values ​​do not belong to the angle values ​​corresponding to the first i-1 second maximum amplitude points, then the current target to be identified is determined to be a real target.

[0069] In the second DBF pattern, A k If the angle value corresponds to the point of minimum amplitude, then it indicates that A kThe corresponding target components have been effectively filtered out. If, among the three angle values, excluding A... k If the two angle values ​​outside the second DBF pattern do not belong to the angle values ​​corresponding to the first two second amplitude maxima points, then these two angle values ​​are determined to be the angle values ​​of false targets caused by side lobes and grating lobes.

[0070] As previously explained, due to the false peaks caused by the grating lobes, there will be a characteristic symmetrical about the target. Therefore, by finding the three first amplitude maxima points ranked in the top three of the first DBF radiation pattern, and obtaining the three angle values ​​corresponding to these three first amplitude maxima points, if the angle corresponding to one of the three first amplitude maxima points is the angle value corresponding to the real target, then the other two first amplitude maxima points are false peaks caused by the grating lobes. Therefore, in this embodiment of the application, if A k If the angle value corresponds to the actual target, then the angle value A in the original signal of the target array is filtered out. k The corresponding theoretical signal component estimate S k Afterwards, the other two signals caused by the grating lobes will also be filtered out. Therefore, the angle values ​​corresponding to the two false peaks caused by the grating lobes will no longer correspond to the amplitude values ​​in the second DBF pattern. Thus, A can be accurately determined. k Is it the angle value corresponding to the actual target?

[0071] For the second DBF pattern, if A k The angle value corresponding to the point of minimum amplitude can then determine A. k The corresponding theoretical signal component estimate S k It has already been filtered out, and further, based on the i angle values ​​divided by A... k In addition, whether the amplitude points corresponding to the i-1 angle values ​​do not belong to the first i-1 second amplitude maxima points in the second DBF pattern can determine A. k Whether it corresponds to the actual target angle value. That is, if the amplitudes corresponding to the i-1 angle values ​​are not the amplitudes of the first i-1 second amplitude maxima points in the second DBF pattern, then A can be determined. k The angle value is the one corresponding to the actual target; otherwise, A k It could be a sidelobe or grating lobe false target, or there might be multiple targets at the same distance and speed in the radar target echo component. k This is only one of the actual target angle values.

[0072] In some embodiments, Figure 1 Based on the provided target recognition method, after step 160, the method further includes: in the second DBF pattern, if A k Angle values ​​that do not correspond to the minimum amplitude point, or excluding A from the i angle values. kIn addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the i-1 largest second maximum amplitude points, then select the angle value A that has not been selected from the i angle values. k Then proceed to the step of filtering A from the radar target echo signal. k The steps for the corresponding signals.

[0073] Among them, when selecting angle value A k When selecting angle values, the angles can be chosen randomly or in a specific order, such as from smallest to largest or from largest to smallest. If i = 3, then among the three angle values ​​corresponding to the first three first amplitude maxima obtained in descending order of the first amplitude maxima, the angle value located between the other two angle values ​​in the first DBF pattern is very likely to be the angle value corresponding to the target object. Therefore, step 140 can prioritize this angle value for subsequent judgments, thereby quickly determining the angle value corresponding to the real target and improving the efficiency of target recognition.

[0074] When step 140 is executed for the first time, k is 1; when this step is executed for the first time, k is 2; when this step is executed for the second time, k is 3, and so on.

[0075] In some embodiments, in order to improve the obtained theoretical signal Y k To ensure accuracy, step b1 includes:

[0076] Step b11: Based on the first preset parameter, A k The calculation index includes the radar array layout, the elevation angle of the actual target, and the wavelength of the radar target echo signal.

[0077] Step b12: Using a preset value as the base and the exponent as the exponent, calculate the theoretical signal Y. k .

[0078] If we only consider targets in different azimuth dimensions within the same pitch dimension, the DBF angle measurement range is -90° to 90°, and the default pitch angle is 0°, then we can use the formula... Calculate the theoretical signal Y k , where Array TR The radar array is arranged in a 1*N configuration, where N is the total number of radar array elements emitting electromagnetic waves into the detection area. For a multi-transmitter / multi-receiver radar array, N is the product of the transmitting and receiving array elements. λ is the wavelength of the signal reflected back from objects within the detection area, i.e., the wavelength of the radar target echo signal, which can be expressed by the formula... The calculation yields a value where c is the speed of light and f is the center frequency of the radar echo signal. The first preset parameter is -2π*j, and its preset value is e.

[0079] If we only consider targets in different azimuth dimensions within the same pitch dimension, the DBF angle measurement range is -90° to 90°. Assuming the pitch angle is not 0° by default, we can use the formula... Formula for calculating theoretical signal Y k , where x arrayTR The x-axis (horizontal direction) position of the radar array arrangement, y arrayTR This represents the y-axis (vertical elevation) position of the radar array arrangement. The target elevation angle, for radar arrays equipped with elevation angle measurement capabilities, can be determined using angle measurement methods such as DBF, amplitude comparison, and phase comparison.

[0080] If we only consider targets in different azimuth dimensions within the same pitch dimension, the DBF angle measurement range is 0° to 180°, with the default pitch angle being 0°. Then we can use the formula... Calculate the theoretical signal Y k .

[0081] To verify the accuracy of the target recognition method provided in this application's embodiments, relevant simulation experimental data will be used for explanation. Among them, Figure 2 A schematic diagram of a radar array in a simulation experiment provided in an embodiment of this application is shown. For example... Figure 2 As shown, the radar array is a 3-transmit, 4-receive array. The arrangement of the transmitting array elements in the diagram refers to the arrangement of the radar transmitting array elements; the arrangement of the receiving array elements refers to the arrangement of the radar receiving array elements. The simulation experiment sets the simulated real target angle at 6° azimuth (default elevation is 0°), the DBF angle measurement setting is the angle scanning range of -90°:0.2°:90°, the number of angle search points M=900, random noise is added, and the target signal-to-noise ratio is set to 20dB. Figure 3 This illustration shows a first DBF radiation pattern and a schematic diagram of the DBF radiation pattern after filtering out the theoretical signal of the real target, as provided in an embodiment of this application. Figure 3As shown in the figure, 1 is the first DBF pattern, and 2 is the DBF pattern after filtering out the theoretical signal of the real target. In the first DBF pattern, point a1 is the point corresponding to the real target, with an angle of 6° and an amplitude of 21.9789dB; point b1 is a false peak point located to the left of the real target caused by the grating lobe, with an angle of -15.8° and an amplitude of 19.5943dB; point c1 is a false peak point located to the right of the real target caused by the grating lobe, with an angle of 28.8° and an amplitude of 19.5909dB. In the DBF pattern after filtering out the theoretical signal of the real target, the amplitudes of points b2, a2, and c2 corresponding to -15.8°, 6°, and 28.8° all decrease and are no longer the amplitude maxima points in the pattern. Furthermore, the angle value of 6° at point a2 corresponds to the angle value of the amplitude minima in the DBF pattern, indicating that point a1 corresponding to 6° belongs to the real target point. Point b1 corresponding to -15.8° is a false peak point located to the left of the real target caused by the grating lobe, and point c1 corresponding to 28.8° is a false peak point located to the right of the real target caused by the grating lobe.

[0082] Figure 4 This illustration shows another first DBF pattern provided by an embodiment of this application, and a schematic diagram of the DBF pattern after filtering out the theoretical signal of the false peak target located to the left of the real target. (See attached diagram.) Figure 4 As shown, 11 is the first DBF pattern, and 31 is the DBF pattern after filtering out the theoretical signal of the false peak target located to the left of the real target. In the figure, point d1 is the point corresponding to the real target, with an angle of 6° and an amplitude of 21.9789dB; point e1 is the false peak point located to the left of the real target caused by the grating lobe, with an angle of -15.8° and an amplitude of 19.5943dB; point f1 is the false peak point located to the right of the real target caused by the grating lobe, with an angle of 28.8° and an amplitude of 19.5909dB. In the DBF pattern 31 after filtering out the theoretical signal of the false peak target located to the left of the real target, the angle of point f2 is 28.8° and the amplitude is 15.6778dB. The amplitudes of points d2 and f2, corresponding to 6° and 28.8° respectively, are still peak values. Figure 3 The DBF pattern results before and after filtering out the real target a1 point show that point e1 is a false peak point located to the left of the real target caused by the grid lobe.

[0083] Figure 5 This illustration shows another first DBF pattern provided by an embodiment of this application, and a schematic diagram of the DBF pattern after filtering out the theoretical signal of the false peak target located to the right of the real target. (See attached diagram.) Figure 5 As shown, 11 is the first DBF pattern, which is related to... Figure 4 The first DBF direction in Figure 1To; 32 is the DBF pattern after filtering out the theoretical signal of the false peak target located to the right of the real target. In DBF pattern 32 after filtering out the theoretical signal of the false peak target located to the right of the real target, the angle of point e2 is -15.8°, and the amplitude is 15.6836dB; the amplitudes of points e2 and d2 corresponding to -15.8° and 6° are still peak values, combined with Figure 3 The DBF pattern results before and after filtering out the real target a1 point show that point f1 is a false peak point located to the right of the real target caused by the grid lobe.

[0084] Figure 6 A schematic diagram of the target recognition device provided in an embodiment of this application is shown. Figure 6 As shown, the device 200 includes: a first acquisition module 201, a first determination module 202, a second acquisition module 203, a filtering module 204, a second determination module 205, and a third determination module 206. The first acquisition module 201 acquires a first digital beamforming (DBF) pattern of the target to be identified, wherein the first DBF pattern is obtained by performing DBF angle measurement on the radar target echo signal. The second module 202 determines multiple first amplitude maxima points based on all amplitude points of the first DBF pattern, wherein each first amplitude maxima point is an amplitude point in the first DBF pattern whose amplitude is greater than the adjacent left and right amplitudes. The second acquisition module 203 acquires i angle values ​​corresponding to the first i first amplitude maxima points in descending order of magnitude, wherein the first i first amplitude maxima points are points corresponding to the target to be identified, i is a positive integer, and i is greater than 1. The filtering module 204 selects an angle value A from the i angle values. k A k The corresponding target is the current target to be identified, and A is filtered out from the radar target echo signal. k The corresponding signal is used to obtain the residual signal component, where k is a positive integer and k≤i. The second determining module 205 is used to determine the second DBF pattern corresponding to the residual signal component. The third determining module 206 is used in the second DBF pattern, if A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second amplitude maxima points, then the current target to be identified is determined to be a real target. Among them, the amplitude minima point is the amplitude point in the second DBF direction pattern whose amplitude is less than the adjacent left and right amplitudes, and the second amplitude maxima point is the amplitude point in the second DBF direction pattern whose amplitude is greater than the adjacent left and right amplitudes.

[0085] The target recognition device provided in this embodiment is used to execute the technical solution of the target recognition method in the aforementioned method embodiment. Its implementation principle and technical effect are similar, and will not be described again here.

[0086] It is worth noting that the target recognition device provided in this embodiment also includes other modules for performing the steps of the above target recognition method embodiment, which will not be described in detail here.

[0087] Figure 7 The diagram shows a structural schematic of a target recognition device provided in an embodiment of this application. The specific embodiments of this application do not limit the specific implementation of the target recognition device.

[0088] like Figure 7 As shown, the target identification device may include: a processor 302, a communications interface 304, a memory 306, and a communications bus 308.

[0089] The processor 302, communication interface 304, and memory 306 communicate with each other via communication bus 308. Communication interface 304 is used to communicate with other network elements, such as clients or other servers. The processor 302 executes program 310, specifically performing the relevant steps described above in the target recognition method embodiment.

[0090] Specifically, program 310 may include program code, which includes computer-executable instructions.

[0091] Processor 302 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application. The target identification device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or they may be processors of different types, such as one or more CPUs and one or more ASICs.

[0092] Memory 306 is used to store program 310. Memory 306 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0093] This application provides a computer-readable storage medium storing executable instructions that, when executed on a target recognition device, cause the target recognition device to perform the target recognition method in any of the above method embodiments.

[0094] This application provides a computer program that can be called by a processor to cause a target recognition device to execute the target recognition method in any of the above method embodiments.

[0095] This application provides a computer program product, which includes a computer program stored on a computer-readable storage medium. The computer program includes program instructions that, when executed on a computer, cause the computer to perform the target recognition method in any of the above method embodiments.

Claims

1. A target recognition method, characterized in that, The method includes: The first digital beamforming (DBF) pattern of the target to be identified is acquired, wherein the first DBF pattern is obtained by performing DBF angle measurement on the radar target echo signal; Based on all amplitude points of the first DBF pattern, multiple first amplitude maxima are determined, wherein each first amplitude maxima is an amplitude point among all amplitude points of the first DBF pattern whose amplitude is greater than the adjacent left and right amplitudes; According to the order of the first amplitude maxima among the plurality of first amplitude maxima points from largest to smallest, obtain the i angle values ​​corresponding to the first i first amplitude maxima points, where the first i first amplitude maxima points are the points corresponding to the target to be identified, i is a positive integer, i is greater than 1; Select angle value A from the i angle values. k The A k The corresponding target is the current target to be identified, and the A target is filtered out from the radar target echo signal. k The corresponding signal yields the residual signal component, where k is a positive integer and k ≤ i; Determine the second DBF pattern corresponding to the residual signal component; In the second DBF pattern, if the A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second amplitude maxima points, then the current target to be identified is determined to be a real target. The amplitude minima point is the amplitude point in the second DBF direction map whose amplitude is smaller than the adjacent left and right amplitudes, and the second amplitude maxima point is the amplitude point in the second DBF direction map whose amplitude is larger than the adjacent left and right amplitudes.

2. The method according to claim 1, characterized in that, The radar target echo signal is the signal reflected back from an object in the detection area after the radar array emits electromagnetic waves into the detection area. The step of filtering out A from the radar target echo signal... k The corresponding signal yields residual signal components, including: According to A k Determine the theoretical signal Y of the target to be identified under the detection of the radar array. k ; According to the first DBF pattern, A k The corresponding numerical value and the Y k Determine the Y k The estimated signal component S in the first DBF pattern k Wherein, the value is a complex number; Filter out the S from the radar target echo signal. k The residual signal components are obtained.

3. The method according to claim 1, characterized in that, If the A k The angle value corresponding to the point of minimum amplitude, and among the i angle values ​​excluding A k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second maximum amplitude points, then the current target to be identified is determined to be a real target, including: Based on all the amplitudes of the second DBF pattern, a plurality of amplitude maxima and a plurality of amplitude minima are determined; Sort the multiple second amplitude maxima points from largest to smallest, and obtain the first i-1 second amplitude maxima points; If the A k The angle value corresponding to one of the multiple amplitude minimum points, and excluding A among the i angle values. k In addition, if the remaining i-1 angle values ​​do not belong to the angle values ​​corresponding to the first i-1 second amplitude maxima points, then the current target to be identified is determined to be the real target.

4. The method according to claim 1, characterized in that, i is 3.

5. The method according to claim 1, characterized in that, The method further includes: In the second DBF pattern, if the A k Angle values ​​that do not correspond to the minimum amplitude point, or excluding A from the i angle values. k In addition, if the remaining i-1 angle values ​​are not the angle values ​​corresponding to the largest i-1 second maximum amplitude points, then select an angle value A that has not been selected from the i angle values. k ; Turn to filtering out A from the radar target echo signal k The corresponding signal is used to obtain the residual signal component.

6. The method according to claim 1, characterized in that, Before acquiring the first DBF pattern of the target to be identified, the method further includes: Acquire the radar target echo signal; Fourier transforms of the radar target echo signal in the range and velocity dimensions are performed to obtain range-Doppler RD spectrum data; The original target array signal S, which acquires the target distance and target velocity from the RD spectrum data, is obtained. origin ; The process of obtaining the first DBF pattern of the target to be identified includes: For the S origin DBF angle measurement is performed to obtain the first DBF pattern.

7. The method according to claim 2, characterized in that, According to A k Determine the theoretical signal Y of the target to be identified under the detection of the radar array. k ,include: According to the first preset parameter, A k The radar array arrangement position, the elevation angle of the actual target, and the wavelength calculation index value of the radar target echo signal; Using a preset value as the base and the exponent value as the exponent, the theoretical signal Y is calculated. k .

8. The method according to claim 2, characterized in that, According to the first DBF pattern, A k The corresponding numerical value and the Y k Determine the Y k The estimated signal component S in the first DBF pattern k ,include: Through formula S k =Y k *S map (A k The S was calculated. k , among which, S map (A k ) represents the stated value.

9. A target recognition device, characterized in that, include: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store executable instructions that cause the processor to perform the operation of the target recognition method as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The storage medium stores executable instructions, which, when executed, perform the target recognition method as described in any one of claims 1-7.

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