Study On Vehicle Millimeter Wave Radar Altimetry Technology

With the advent of the era of intelligent driving,intelligent driving system is the core of sensors become each big auto makers to focus on the object of study,including car millimeter wave radar,compared with other sensors are low cost,small volume,strong penetrability,it makes the car millimeter wave radar has become an important part of intelligent driving system in the link.However,most vehicle-mounted MMW radars in the current market still do not have the function of height measurement or the ability of height measurement is limited,so the research on vehicle-mounted MMW radar height measurement technology is of great significance.This paper focuses on the vehicle millimeter wave radar altimetry task,and the specific work is as follows:1.Target echo mathematical signal model under multipath condition is established for common auto driving scenarios;The boundary conditions of multipath generation and the inlet conditions of multipath and direct wave separation are analyzed.The direct wave and multipath separation conditions of common targets are studied and verified by simulation experiments.2.Aiming at the problem that traditional millimeter wave radar cannot separate direct wave and multipath wave due to its poor angular resolution,a time-domain spectral analysis altimetry method using a single receiving antenna is studied.Analyzed the height measurement method of target distance range,the influence factors such as sampling interval and the antenna height,and gives the option of high parameter,set up the experiment system,using the measured data to verify the proposed factors affecting the effectiveness of the solution,respectively to estimate the target Angle of the low and high goals in the two types of height of target height.3.The overall array error of large aperture millimeter wave radar and its correction scheme are studied.Large aperture millimeter wave radar has array amplitude-phase error and nearfield phase error caused by near-field effect.The estimation and correction of these two kinds of errors must be completed before array Angle measurement.Aiming at the amplitudephase error of radar array,the active amplitude-phase error correction method using calibration body is studied.The influence of distance and azimuth on the phase error of near field is verified by theoretical analysis and simulation.According to the characteristics of the two influencing factors,a radar amplitude-phase error table is established,and the array error is corrected by table lookup method,and the accuracy of the method is verified by simulation analysis.Finally,the MIMO large aperture millimeter-wave radar experiment system is built,and the near-field phase error correction method and radar overall array error correction method are verified by experiments in microwave anechoic chamber and open environment.4.Aiming at the height measurement problem of large aperture millimeter wave radar,the two methods of super-resolution Angle measurement after understanding the coherence and DBF Angle measurement are compared and analyzed.The resolution and high performance of the two algorithms are simulated and analyzed,and the feasibility of the proposed scheme is verified.Aiming at the actual field experiment,the radar height calibration method and array inclination estimation method using the calibration body are studied,and the feasibility of the alt-measuring scheme is verified by the measured data.