Research On Radar Target Detection Algorithm In Complex Traffic Environment

Target detection is an important part of automatic driving technology,which is the premise of decision and control.For automatic driving,millimeter wave(MMW)radar has become one of the vital sensors in target detection.Because of it is low cost,all-weather and small size.The result of MMW radar target detection directly affects the result of decision-level multi-sensor fusion.In order to ensure people’s travel safety,it is of great significance to study radar target detection algorithm in complex traffic environment.In MMW radar target detection technology,Constant False Alarm Rate(CFAR)processing is very important.This thesis focuses on the target detection of vehicle-mounted millimeter wave radar in complex traffic environment,and researches the target detection algorithm of millimeter wave radar.The main work is as follows:1.This thesis firstly introduces the system of MMW radar and introduces the difference between triangle wave and sawtooth wave in linear frequency modulated continuous wave system.The principles of distance measurement,velocity measurement and Angle measurement of sawtooth wave signal are described in detail.This chapter introduces the principle of Gaussian distributed clutter model and the calculation formula of false alarm probability.2.The principle and characteristics of several classical CFAR detectors are analyzed.The detection threshold of CFAR detector was simulated and analyzed by simulation experiment.Aiming at the problem of poor detection performance of traditional CFAR detector in traffic environment with multi-targets and strong clutter background,Two improved CFAR detectors,Multiple Switching CFAR(MS-CFAR)and Adaptive Censoring CFAR(AC-CFAR),are designed.MS-CFAR detector improves the performance of CFAR detector by refining background environment classification.The AC-CFAR detector distinguishes the background environment by the step point and the variation index,and selects the traditional CFAR strategy to calculate the detection threshold.Monte Carlo method was used to compare the performance difference between the improved CFAR and the traditional CFAR detector in non-uniform environment.The simulation results show that both MS-CFAR and AC-CFAR have good detection performance in non-uniform environment,so the detection performance of millimeter-wave radar in complex traffic environment can be improved.3.AWR1642 development board is used to verify the detection performance of MS-CFAR and AC-CFAR detectors in the actual environment.The data processing flow of millimeter wave radar for target detection is analyzed.The software and hardware experimental conditions required for actual environment testing are introduced.The MS-CFAR and AC-CFAR detectors were transplanted into the code of MMW radar target detection,and the code was burned to AWR1642 development board.The AWR1642 development board with code burning was placed in a variety of preset actual road environments to verify the detection performance of MMW radars transplanted with MS-CFAR and AC-CFAR detectors in the actual environment.The measured results show that the AWR1642 development board transplanted with MS-CFAR or AC-CFAR detector can detect the speed,distance and Angle of various targets in the traffic environment with strong noise and multiple interference targets in real time.The performance of radar target detection algorithm using CFAR detector is tested on CRUW data set.The results show that the detection performance of MS-CFAR and AC-CFAR is better than that of traditional CFAR detector in multi-target environment.