Investigation Of Anti-interference Of Vehicle-mounted LiDAR Based On Frequency-hopping

LiDAR is one of the critical sensors for autonomous driving environment perception.However,in an actual traffic environment,multiple Li DAR signals interfere with each other,which leads to false alarm recognition and endangers the safety of automatic driving.Therefore,the research on anti-interference vehicle-mounted li DAR is a necessary prerequisite for the safe and stable driving of unmanned vehicles in the future.The demand is urgent and the application prospect is bright.Based on analyzing the phenomena of LiDAR interference and anti-interference technology at home and abroad,for the mutual interference(MI)issue between Li DARs.In the thesis,puts forward the frequency-hopping(FH)Li DAR system,studies the basic principle of FH Li DAR,and determines the laser signal generation method based on FH modulation.The signal processing algorithm is studied and the signal processing method based on correlation detection is formed.Based on the FH anti-interference system,the antiinterference performance with pulse,continuous wave(CW),frequency-modulated continuous-wave(FMCW)and the same type of FH interference is simulated and analyzed.The system of FH anti-interference is built and the experimental study of anti-interference performance is carried out.The main research contents of this paper are as follows:(1)An anti-interference LiDAR method based on FH modulation has been proposed.A FH anti-interference Li DAR system has been designed,and the least mean square(LMS)algorithm and the correlation algorithm of interference echo signal processing based on FH modulation are theoretically analyzed and deduced.(2)The generation and receiving of FH modulation laser are studied.In simulation,setting the FH number at 10 000,the FH residence time is 1 microsecond for the largest detection range at 150 meters.For the different intensities and quantities of interference signals,including the Pulse,CW,FMCW and the same type of FH interference signal,which might have the influence on the range detection performance to the FH Li DAR been studied.The influence of Gaussian Noise in FH Li DAR receiver on ranging result is analyzed.In addition,the velocity detection algorithm of radial moving target by FH Li DAR also has been analyzed.(3)The anti-interference performance of FH Li DAR based on correlation algorithm is studied experimentally.In the study of the anti-interference ability of FH Li DAR,the accuracy of ranging results under Pulse,CW,FMCW and the same type of FH interference signals are studied deeply,and several groups of ranging data are measured,and the relative measurement errors are analyzed.At the same time,the reason of anti-interference of FH Li DAR based on correlation algorithm also has been analyzed.The experimental results show that the system can effectively achieve stable and reliable ranging,the maximum distance error is 2cm,and the maximum relative ranging error is ±0.9%.It can meet the requirements of unmanned vehicle-mounted Li DAR antiinterference application.