A radar two-dimensional angle measurement evaluation method based on amplitude and phase errors

Abstract

The present invention relates to a radar two-dimensional angle measurement evaluation method based on amplitude and phase errors. By analyzing the influence of materials such as bumpers in the radar deployment environment on angle measurement, the method obtains the amplitude and phase errors under the two-dimensional angle FOV at the actual radar deployment position, adds them to the two-dimensional angle measurement model for angle estimation, and obtains the radar azimuth and pitch angle, thereby accurately analyzing the radar two-dimensional angle measurement.

Description

Technical Field

[0001] The present invention relates to the field of radar technology, and in particular to a radar two-dimensional angle measurement evaluation method based on amplitude and phase errors. Background Art

[0002] Currently, it is difficult to model and analyze the radar detection performance of radars with different specific radome materials or shapes in advance.

[0003] Although some existing vehicle-mounted millimeter-wave angle radars have the functions of vertical angle and height measurement, they are difficult to quantitatively analyze the two-dimensional angle measurement of the radar, which is affected by the car's radar bumper or antenna cover, especially when it comes to the coupling problem of horizontal and vertical angle resolution. Summary of the Invention

[0004] In response to the problems existing in the prior art, the purpose of the present invention is to provide a radar two-dimensional angle measurement evaluation method based on amplitude and phase errors. By analyzing the influence of materials such as bumpers in the radar deployment environment on angle measurement, the amplitude and phase errors under the two-dimensional angle FOV at the actual radar deployment position are obtained and added to the two-dimensional angle measurement model for angle estimation, thereby obtaining the radar azimuth and pitch angles, thereby accurately analyzing the radar two-dimensional angle measurement.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] A radar two-dimensional angle measurement evaluation method based on amplitude and phase errors, the method comprising the following steps:

[0007] Step 1: Import the car bumper 3D model data and radar layout information, and simulate with HFSS software to obtain the amplitude and phase data of each radar channel;

[0008] Step 2: Perform linear fitting based on the phase data of each channel at each angle to obtain the fitted phase; subtract the fitted phase from the simulated phase obtained by HFSS software to obtain the phase difference at the corresponding angle; extract the amplitude of the azimuth dimension angle measurement channel and , phase difference and ; Extract the amplitude of the pitch angle measurement channel and , phase difference and ;

[0009] Step 3: Import the amplitude and phase difference of the azimuth and elevation angle measurement channels into MATLAB for modeling and simulation to obtain the simulated installation angle of the radar; subtract the simulated installation angle from the actual installation angle of the radar to obtain the angle measurement error;

[0010] Step 4: Use the angle measurement error obtained in step 3 to evaluate the angle measurement effect of the current radar placement position on this type of bumper. If the effect meets expectations, the assessment concludes that the current radar placement position is feasible. If the effect does not meet expectations, adjust the radar position in the HFSS software and repeat steps 1 to 4 to re-evaluate.

[0011] In step 3, the installation angle of the radar simulation is obtained as follows:

[0012] Add amplitude and phase errors in azimuth and elevation dimensions respectively to construct the following model:

[0013] ;

[0014] Since it is necessary to consider the amplitude and error level of each channel at different angles, we have:

[0015]

[0016] The angle is When , the amplitude corresponding to the i-th receiving channel; The angle is When , the phase error corresponding to the i-th receiving channel; P1 is the number of channels of the main sub-array in the direction; and Represent the coordinates of the azimuth and elevation dimensions of the i-th virtual channel respectively; the azimuth and elevation angles of the target are θ and , A is the signal amplitude, N is the noise, ;

[0017] Similarly, the amplitude and phase data at each angle generated by the HFSS software are traversed to generate the superimposed phase error data at other angles, and the received signal vectors at all angles of interest are obtained:

[0018] ;

[0019] The steering vector of the radar main array is:

[0020]

[0021] Assume that P2 is the number of channels in the elevation direction from the main sub-array, Angle When , the amplitude corresponding to the i-th receiving channel of the slave subarray, the radar signal from the slave subarray is:

[0022]

[0023] Similarly, the received signal vectors under all angles of FOV of the sub-array are:

[0024]

[0025] The steering vector from the sub-array is:

[0026]

[0027] when When , DBF beamforming is performed on the master sub-array and the slave sub-array respectively:

[0028]

[0029]

[0030] The radar elevation signal is:

[0031]

[0032] If the number of pitch channels is P3, the pitch steering vector is

[0033]

[0034] Perform DBF beam synthesis and obtain

[0035]

[0036] According to the spectrum of DBF, the corresponding angle value can be easily calculated. The symbol |·| represents the modulo operation:

[0037]

[0038]

[0039] Further derive azimuth information:

[0040] .

[0041] In the step 1, the automobile bumper 3D molding data includes bumper shape node constants and loss tangent parameters.

[0042] After adopting the above scheme, the present invention can take into account the analysis of azimuth and elevation angle measurement capabilities, and realize antenna simulation based on the actual characteristics of the mold material to obtain amplitude and phase information. The phase center and phase error are calculated with the help of the phase fitting method. On this basis, the relevant error information is added to the two-dimensional angle measurement model distribution to evaluate the measurement error level of the radar azimuth and elevation angles, which greatly reduces the product development cycle. According to the model simulation results, the error level of each angle and the direction in which the radar needs to be adjusted can be known in advance. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a flow chart of the method of the present invention;

[0044] Figure 2 Schematic diagram of radar two-dimensional angle measurement. DETAILED DESCRIPTION

[0045] like Figure 1 As shown, the present invention discloses a radar two-dimensional angle measurement evaluation method based on amplitude and phase errors. It adopts the idea of ​​HFSS layout simulation and modeling, extracts corresponding data for model simulation, and is applicable to angle measurement analysis in any scenario. The closer the analysis model is to the actual situation, the radar development cycle can be greatly reduced, and even optimization directions for position layout improvement can be proposed in advance.

[0046] Specifically, the radar two-dimensional angle measurement evaluation method of the present invention includes the following steps:

[0047] Step 1: Import the 3D bumper model data and radar layout information, and simulate using HFSS software to obtain the amplitude and phase data of each radar channel. The 3D bumper model data includes bumper shape node constants and loss tangent parameters.

[0048] Step 2: Perform linear fitting based on the phase data of each channel at each angle to obtain the fitted phase; subtract the fitted phase from the simulated phase obtained by HFSS software to obtain the phase difference at the corresponding angle; extract the amplitude of the azimuth dimension angle measurement channel and , phase difference and ; Extract the amplitude of the pitch angle measurement channel and , phase difference and .

[0049] Step 3: Import the amplitude and phase difference of the azimuth and elevation angle measurement channels into MATLAB for modeling and simulation to obtain the simulated installation angle of the radar; subtract the simulated installation angle from the actual installation angle of the radar (i.e., the radar layout position information in step 1) to obtain the angle measurement error.

[0050] Specifically, the definition of radar two-dimensional angle measurement is as follows Figure 2 As shown, XOZ is the array of virtual antennas, OX represents the azimuth dimension of the radar, and OY represents the elevation dimension of the radar. and Represent the coordinates of the azimuth and elevation dimensions of the i-th virtual channel. The azimuth and elevation angles of the target are θ and , A is the signal amplitude, N is the noise, then the received signal of each virtual channel is:

[0051]

[0052]

[0053] make ,but

[0054]

[0055] However, the above is a purely ideal theoretical model. By adding amplitude and phase errors in the azimuth and elevation dimensions, we can construct the following model:

[0056] Since the actual receiving channels are not equally spaced, in order to maintain generality, the radar azimuth angle estimation signal is: ;

[0057] Since it is necessary to consider the amplitude and error level of each channel at different angles, we have:

[0058]

[0059] The angle is When , the amplitude corresponding to the i-th receiving channel; The angle is When , the phase error corresponding to the i-th receiving channel is; P1 is the number of channels of the main sub-array in the direction.

[0060] Similarly, by using the amplitude and phase data at each angle generated by the HFSS software to traverse and generate the superimposed phase error data at other angles, the received signal vector at all angles of interest can be obtained:

[0061]

[0062] The steering vector of the radar main array is:

[0063]

[0064] Assume that P2 is the number of channels in the elevation direction from the main sub-array, Angle When , the amplitude corresponding to the i-th receiving channel of the slave subarray, the radar signal from the slave subarray is:

[0065]

[0066] Similarly, the received signal vectors under all angles of FOV of the sub-array are:

[0067]

[0068] The steering vector from the sub-array is:

[0069]

[0070] when When , DBF beamforming is performed on the master sub-array and the slave sub-array respectively:

[0071]

[0072]

[0073] The radar elevation signal is:

[0074]

[0075] It is worth noting that when evaluating the pitch angle performance, the amplitudes of different sub-arrays in the horizontal angle measurement dimension are replaced accordingly: and 、 and , replaced by the parameters of vertical angle measurement: and 、 and This is mainly because the amplitude and phase errors in different dimensions are different. The error level corresponding to the angle within the vertical FOV needs to be added for beamforming processing.

[0076] If the number of pitch channels is P3, the pitch steering vector is

[0077]

[0078] Perform DBF beam synthesis and obtain

[0079]

[0080] According to the spectrum of DBF, the corresponding angle value can be easily calculated. The symbol |·| represents the modulo operation:

[0081]

[0082]

[0083] That is, it is easy to get the azimuth information:

[0084]

[0085] The azimuth angle obtained by the above simulation and pitch angle Subtract the actual installation position of the radar in step 1 to obtain the angle measurement error.

[0086] Step 4: Use the angle measurement error obtained in step 3 to evaluate the angle measurement effect of the current radar placement position on this type of bumper. If the effect meets expectations, the assessment concludes that the current radar placement position is feasible. If the effect does not meet expectations, adjust the radar position in the HFSS software and repeat steps 1 to 4 to re-evaluate.

[0087] In summary, the present invention can take into account the analysis of azimuth and elevation angle measurement capabilities, and realize antenna simulation based on the actual characteristics of the mold material to obtain amplitude and phase information. The phase center and phase error are calculated with the help of the phase fitting method. On this basis, the relevant error information is added to the two-dimensional angle measurement model distribution to evaluate the measurement error level of the radar azimuth and elevation angles, which greatly reduces the product development cycle. According to the model simulation results, the error level of each angle and the direction in which the radar needs to be adjusted can be known in advance.

[0088] The above description is merely an embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A radar two-dimensional angle measurement evaluation method based on amplitude and phase errors, characterized by: The method comprises the following steps: Step 1: Import the car bumper 3D model data and radar layout information, and simulate with HFSS software to obtain the amplitude and phase data of each radar channel; Step 2: Perform linear fitting based on the phase data of each channel at each angle to obtain the fitted phase; subtract the fitted phase from the simulated phase obtained by HFSS software to obtain the phase difference at the corresponding angle; extract the amplitude of the azimuth dimension angle measurement channel and , phase difference and ; Extract the amplitude of the pitch angle measurement channel and , phase difference and ; Step 3: Import the amplitude and phase difference of the azimuth and elevation angle measurement channels into MATLAB for modeling and simulation to obtain the simulated installation angle of the radar; subtract the simulated installation angle from the actual installation angle of the radar to obtain the angle measurement error; Step 4: Use the angle measurement error obtained in step 3 to evaluate the angle measurement effect of the current radar placement position on this type of bumper. If the effect meets expectations, the assessment concludes that the current radar placement position is feasible. If the effect does not meet expectations, adjust the radar position in the HFSS software and repeat steps 1 to 4 to re-evaluate.

2. The radar two-dimensional angle measurement evaluation method based on amplitude and phase errors according to claim 1, characterized in that: In step 3, the installation angle of the radar simulation is obtained as follows: Add amplitude and phase errors in azimuth and elevation dimensions respectively to construct the following model: ； Since it is necessary to consider the amplitude and error level of each channel at different angles, we have: The angle is When , the amplitude corresponding to the i-th receiving channel; The angle is When , the phase error corresponding to the i-th receiving channel; P1 is the number of channels of the main sub-array in the direction; and Represent the coordinates of the azimuth and pitch dimensions of the i-th virtual channel respectively; the azimuth and pitch angles of the target are θ and , A is the signal amplitude, N is the noise, ; Similarly, the amplitude and phase data at each angle generated by the HFSS software are traversed to generate the superimposed phase error data at other angles, and the received signal vectors at all angles of interest are obtained: ； The steering vector of the radar main array is: Assume that P2 is the number of channels in the elevation direction from the main sub-array, Angle When , the amplitude corresponding to the i-th receiving channel of the slave subarray, the radar signal from the slave subarray is: Similarly, the received signal vectors under all angles of FOV of the sub-array are: The steering vector from the sub-array is: when When , DBF beamforming is performed on the master sub-array and the slave sub-array respectively: The radar elevation signal is: If the number of pitch channels is P3, the pitch steering vector is Perform DBF beam synthesis and obtain According to the spectrum of DBF, the corresponding angle value is found. The symbol |·| represents the modulo operation: Further derive azimuth information: 。 3. The radar two-dimensional angle measurement evaluation method based on amplitude and phase errors according to claim 1, characterized in that: In the step 1, the automobile bumper 3D molding data includes bumper shape node constants and loss tangent parameters.

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