Angle measurement method, device, terminal and medium based on angle correction

Abstract

The present application discloses an angle measurement method, device, terminal and medium based on angle correction, the method comprising: obtaining the DBF angle measurement curve of the target; obtaining the maximum amplitude and the second largest extreme value of the target DBF angle measurement curve; if the difference between the maximum amplitude and the second largest extreme value is less than a preset value, it is judged that there are two target angles; when the absolute value of the azimuth difference of two targets with the same speed and distance is within 0.73~1.4 times of the 3db beam width, there is a linear relationship between the absolute value of the angle difference of the two targets and the angle complement value, and the angles of the two targets are corrected respectively according to the linear relationship; when the absolute value of the azimuth difference of the two targets is between 1.4~1.5 times of the 3db beam width, the angle complement value is a constant. The logic of the angle correction of the two targets is to subtract the complement value from the measured small angle and add the complement value to the large angle. The present application can obtain target angle measurement with higher accuracy and solve the problem of inaccurate angle measurement of targets with the same speed and distance.

Description

Technical Field

[0001] The present application relates to the field of radar technology, and in particular to an angle measurement method, device, terminal and medium based on angle correction. Background Art

[0002] Compared with traditional infrared, laser, ultrasonic and other sensors, millimeter-wave radar is less affected by the environment and has high resolution in ranging, speed and angle measurement. It has unique use value and broad application prospects in the direction of target resolution.

[0003] With the development of intelligent driving and 4D millimeter wave radar, higher and higher requirements are placed on the angle resolution of targets. Traditional angle measurement methods are often based on digital beam forming (DBF) and fast Fourier transform (FFT) methods, and their angle resolution capabilities are limited by the 3db beam width of the antenna array.

[0004] When the azimuth angle difference between two targets at the same speed and distance is within the range of 0.73~1.5 times the 3db beam width, the DBF or FFT angle measurement curve will show two peaks, that is, the two targets are distinguishable. However, since the two targets are close, the target angles will affect each other, so the angle measurement result will deviate from the true value. Summary of the invention

[0005] The present application provides an angle measurement method, device, terminal and medium based on angle correction, which has the advantage of obtaining a more accurate target angle measurement by performing angle correction on the angle measurement obtained by the DBF method, thereby solving the problem of inaccurate angle measurement of targets at the same speed and distance.

[0006] The above-mentioned object of the present application is achieved through the following technical solutions:

[0007] On the one hand, the present application provides an angle measurement method based on angle correction, comprising the following steps:

[0008] Step 1: Obtain the DBF angle measurement curve of the target;

[0009] Step 2: Obtain the maximum amplitude of the target DBF angle measurement curve, recorded as , find the second largest extreme value of the DBF angle measurement curve, denoted as ;

[0010] Step 3: If the difference between the maximum amplitude and the second maximum amplitude is less than the preset value , then it is determined that there are two target angles, and step 4 is executed; otherwise, it is considered that there are no two targets with the same speed and distance;

[0011] Step 4: and The angles corresponding to the two extreme points are recorded as , , calculate the absolute value of the angle difference between the two targets , calculate the absolute value of the angle difference between the two targets With 3db beamwidth The ratio of ,according to Complementary value of angle measurement of two targets by segment calculation :

[0012] ;

[0013] in, k is the slope of the linear function, b is the intercept of the linear function, c is a constant term;

[0014] Step 5: Correct the azimuths of two targets at the same speed and distance based on the calculated compensation value:

[0015] .

[0016] Furthermore, the slope of the linear function k The value range is , the intercept of the linear function b The value range is ,constant .

[0017] On the other hand, the present application provides an angle measuring device based on angle correction, comprising:

[0018] A target DBF angle measurement curve acquisition module is used to acquire the DBF angle measurement curve of the target;

[0019] The same-distance and same-speed target judgment module is used to judge whether there are two targets with the same speed and distance. The method is: find the maximum amplitude of the target DBF angle measurement curve, recorded as , find the second largest extreme value of the DBF angle measurement curve, denoted as , if the difference between the maximum amplitude and the second maximum amplitude is less than the preset value , then it is judged that there are two target angles; otherwise, it is considered that there are no two targets with the same speed and distance;

[0020] Compensation calculation module, used to calculate the compensation value of target angle measurement ; The method is: and The angles corresponding to the two extreme points are recorded as , , calculate the absolute value of the angle difference between the two targets , calculate the absolute value of the angle difference between the two targets With 3db beamwidth The ratio of ,according to Complementary value of angle measurement of two targets by segment calculation :

[0021] ;

[0022] in, k is the slope of the linear function, b is the intercept of the linear function, c is a constant term;

[0023] The azimuth correction module is used to correct the azimuth of two targets at the same speed and distance according to the calculated compensation value:

[0024] .

[0025] On the other hand, the present application provides a radar signal processing terminal, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is called and executed by the processor, the angle measurement method based on angle correction as described above is implemented.

[0026] On the other hand, the present application provides a computer-readable medium, characterized in that a computer program is stored in the computer-readable medium, and when the computer program is called and executed by a computer, the angle measurement method based on angle correction as described above is implemented.

[0027] In summary, the beneficial effects of this application are:

[0028] 1. This application corrects the angle measurement obtained by the DBF method to obtain a more accurate target angle measurement, solving the problem of inaccurate angle measurement of targets at the same speed and distance;

[0029] 2. The method proposed in this application is simple and easy to calculate, and when implemented through a computer program, the program efficiency is high;

[0030] 3. When the present application method is used in combination with the traditional DBF or FFT angle measurement method, the resolution of the traditional DBF or FFT method can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the corresponding relationship between the angle compensation and the absolute value of the predicted target angle difference in a specific embodiment of the present application;

[0032] Figure 2 It is a DBF angle measurement curve diagram of a group of targets at the same distance and speed in a specific embodiment of the present application;

[0033] Figure 3 This is a DBF angle measurement curve diagram of another group of targets at the same distance and speed in a specific embodiment of the present application;

[0034] Figure 4 This is a schematic diagram of uncorrected results of ten groups of target angle measurements in a specific embodiment of the present application;

[0035] Figure 5 is a schematic diagram of ten groups of target angle measurement correction results in a specific embodiment of the present application;

[0036] Figure 6 It is a diagram of target distance, speed and angle information of ten groups with the same speed and distance in a specific embodiment of the present application;

[0037] Figure 7 This is a comparison diagram of the actual angles, uncorrected angles and corrected angles of ten groups of targets at the same speed and distance in a specific embodiment of the present application. DETAILED DESCRIPTION

[0038] The specific implementation of the present application is described in detail below with reference to the accompanying drawings.

[0039] A specific embodiment of the present application provides an angle measurement method based on angle correction, comprising the following steps:

[0040] Step 1: Obtain the DBF angle measurement curve of the target;

[0041] Step 2: Obtain the maximum amplitude of the target DBF angle measurement curve, recorded as , find the second largest extreme value of the DBF angle measurement curve, denoted as ;

[0042] Step 3: If the difference between the maximum amplitude and the second maximum amplitude is less than the preset value , then it is determined that there are two target angles, and step 4 is executed; otherwise, it is considered that there are no two targets with the same speed and distance;

[0043] Step 4: and The angles corresponding to the two extreme points are recorded as , , calculate the absolute value of the angle difference between the two targets , calculate the absolute value of the angle difference between the two targets With 3db beamwidth The ratio of ,according to Calculate the complementary value of the angle measurement of two targets in sections :

[0044] ;

[0045] in, k is the slope of the linear function, b is the intercept of the linear function, cis a constant term; the slope of the linear function k The value range is , the intercept of the linear function b The value range is ,constant .

[0046] Step 5: Correct the azimuths of two targets at the same speed and distance based on the calculated compensation value:

[0047] .

[0048] When the absolute value of the azimuth difference of two targets with the same speed and distance is within 0.73~1.4 times of the 3db beam width, there is a linear relationship between the absolute value of the angle difference of the two targets and the angle compensation value, and the angles of the two targets can be corrected according to the linear relationship; when the absolute value of the azimuth difference of the two targets is between 1.4~1.5 times of the 3db beam width, the angle compensation value is a constant. The logic of the angle correction of the two targets is to subtract the compensation value for small angles and add the compensation value for large angles.

[0049] The effectiveness of the present invention is illustrated in a specific application scenario. In this specific application scenario, the millimeter wave radar carrier frequency is 76.5 GHz, the linear array has 24 elements, the element spacing is half a wavelength, and its 3 dB beam width is 4.2303°, set the difference threshold between the maximum amplitude and the second maximum amplitude of the DBF angle measurement curve is 3db, the angle compensation formula k is -0.4256, b is 1.3647, c is -1.1.

[0050] Ten groups of targets with the same speed and distance are set to verify this method. The distance, speed and angle information of the ten groups of targets with the same speed and distance are shown in Figure 6 .

[0051] The methods are explained using the first and third groups of objectives respectively.

[0052] Taking the first group of targets as an example, the DBF angle measurement curve of the first group of targets is shown in Figure 2 .

[0053] The difference between the maximum amplitude of the DBF angle measurement curve and the second maximum extreme point is , less than , then it is judged that there are two targets with the same speed and distance.

[0054] calculate ,because , then the angle compensation is:

[0055] ,

[0056] at this time , so the corrected angle is

[0057] Taking the third group of targets as an example, the DBF angle measurement curve is shown in Figure 3 .

[0058] The difference between the maximum amplitude of the DBF angle measurement curve and the second maximum extreme point is , less than , then it is judged that there are two targets with the same speed and distance.

[0059] calculate .

[0060] because , then the value is .

[0061] at this time , so the corrected angle is:

[0062] .

[0063] The uncorrected angle measurement results of ten groups of targets with the same speed and distance are as follows Figure 4 As shown in the figure, the angle measurement results of ten groups of targets with the same speed and distance after angle correction are as follows: Figure 5 As shown. The center of the circle in the figure is the true value of the target angle, and the dot is the predicted value of the target angle. Comparing the two figures, it can be found that when the target angle is not corrected, the angle measurement result deviates from the center of the circle; after the target angle is corrected, the angle measurement result basically coincides with the center of the circle. It is proved that this method corrects the measured angles of two targets with the same speed and distance when the azimuth difference is within 0.73~1.5 times the 3db beam width, and the angle measurement accuracy is high after correction.

[0064] Figure 7 is the list of angle measurement results, Figure 7 The specific results of the true angle, uncorrected angle and corrected angle of ten groups of targets with the same speed and distance are shown in the figure.

[0065] Another specific embodiment of the present application provides an angle measuring device based on angle correction, comprising:

[0066] A target DBF angle measurement curve acquisition module is used to acquire the DBF angle measurement curve of the target;

[0067] The same-distance and same-speed target judgment module is used to judge whether there are two targets with the same speed and distance. The method is: find the maximum amplitude of the target DBF angle measurement curve, recorded as , find the second largest extreme value of the DBF angle measurement curve, denoted as , if the difference between the maximum amplitude and the second maximum amplitude is less than the preset value , then it is judged that there are two target angles; otherwise, it is considered that there are no two targets with the same speed and distance;

[0068] Compensation calculation module, used to calculate the compensation value of target angle measurement ; The method is: and The angles corresponding to the two extreme points are recorded as , , calculate the absolute value of the angle difference between the two targets , calculate the absolute value of the angle difference between the two targets With 3db beamwidth The ratio of ,according to Calculate the complementary value of the angle measurement of two targets in sections :

[0069] ;

[0070] in, k is the slope of the linear function, b is the intercept of the linear function, c is a constant term;

[0071] The azimuth correction module is used to correct the azimuth of two targets at the same speed and distance according to the calculated compensation value:

[0072] .

[0073] Another specific embodiment of the present application provides a radar signal processing terminal, including a processor and a memory, wherein the memory stores a computer program, and when the computer program is called and executed by the processor, the angle measurement method based on angle correction as described above is implemented.

[0074] Another specific embodiment of the present application provides a computer-readable medium, in which a computer program is stored. When the computer program is called and executed by a computer, the angle measurement method based on angle correction as described above is implemented.

[0075] The above is only a preferred implementation of the present application. It should be pointed out that a person skilled in the art can make several modifications and improvements without departing from the inventive concept of the present application, and these all fall within the scope of protection of the present application.

Claims

1. An angle measurement method based on angle correction, characterized in that: The following steps are involved: Step 1: Obtain the DBF angle measurement curve of the target; Step 2: Obtain the maximum amplitude of the target DBF angle measurement curve, recorded as , find the second largest extreme value of the DBF angle measurement curve, denoted as ; Step 3: If the difference between the maximum amplitude and the second maximum amplitude is less than the preset value , then it is determined that there are two target angles, and step 4 is executed; otherwise, it is considered that there are no two targets with the same speed and distance; Step 4: and The angles corresponding to the two extreme points are recorded as , , calculate the absolute value of the angle difference between the two targets , calculate the absolute value of the angle difference between the two targets With 3db beamwidth The ratio of ,according to Calculate the complementary value of the angle measurement of two targets in sections : ； in, k is the slope of the linear function, b is the intercept of the linear function, c is a constant term; Slope of a linear function k The value range is , the intercept of the linear function b The value range is ,constant ; Step 5: Correct the azimuths of two targets at the same speed and distance based on the calculated compensation value: 。 2. An angle measuring device based on angle correction, characterized in that: include: A target DBF angle measurement curve acquisition module is used to acquire the DBF angle measurement curve of the target; The same-distance and same-speed target judgment module is used to judge whether there are two targets with the same speed and distance. The method is: find the maximum amplitude of the target DBF angle measurement curve, recorded as , find the second largest extreme value of the DBF angle measurement curve, denoted as , if the difference between the maximum amplitude and the second maximum amplitude is less than the preset value , then it is judged that there are two target angles; otherwise, it is considered that there are no two targets with the same speed and distance; Compensation calculation module, used to calculate the compensation value of target angle measurement ; The method is: and The angles corresponding to the two extreme points are recorded as , , calculate the absolute value of the angle difference between the two targets , calculate the absolute value of the angle difference between the two targets With 3db beamwidth The ratio of ,according to Calculate the complementary value of the angle measurement of two targets in sections : ； in, k is the slope of the linear function, b is the intercept of the linear function, c is a constant term; Slope of a linear function k The value range is , the intercept of the linear function b The value range is ,constant ; The azimuth correction module is used to correct the azimuth of two targets at the same speed and distance according to the calculated compensation value: 。 3. A radar signal processing terminal, characterized in that: It comprises a processor and a memory, wherein the memory stores a computer program, and when the computer program is called and executed by the processor, the angle measurement method based on angle correction as claimed in claim 1 is implemented.

4. A computer-readable medium, characterized in that The computer readable medium stores a computer program, and when the computer program is called and executed by a computer, the angle measurement method based on angle correction as claimed in claim 1 is implemented.

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