Research On Key Technology For Security Based On Millimeter-Wave Radar

With the development of society and the continuous improvement of people's living quality,people's awareness of safety precautions has gradually increased.Security needs in key areas such as general factories,prisons,airports,communication base stations,border areas,rail transit,and the entire perimeter of the force station and ammunition depots and firearms are also increasing.Traditional security devices are video cameras,infrared,laser,fiber optic,and leaky cables.Video is subject to environmental interference,prone to false positives,and cannot work for all day and in all kind of weather condition;Lasers and optical fibers are highly demanding for installation,and leaky cables can only alarm and have no positioning function.Traditional security equipment has many shortcomings.Compared with traditional equipment,millimeter-wave radar has small size,light weight,all-weather work,easy deployment and installation,strong anti-interference ability,precise positioning and tracking,and convenient for multiple radar networking,etc.Facing the security needs of important regions of the country,millimeter-wave radar is chosen as a security device by comparing domestic and foreign research trends.For the security applications of millimeter wave radar,this thesis mainly focuses on the research on multi-objective,detection and tracking:(1)Briefly introducing the LFMCW waveform,its ambiguity function and analyzing the range resolution and maximum no ambiguity velocity.The overall data processing flow of millimeter wave data is introduced,and the echo model is constructed and analyzed.The multiple period phase-coherent accumulation method is used to obtain the Range-Doppler ambiguity and then the distance and velocity parameters of moving targets are estimated.According to the one transmitting and two receiving antenna system,the phase comparison angle measurement principle is introduced and two problems i.e.,angular jitter and no spatial resolution of millimeter-wave radar are presented.(2)The CFAR detection algorithm is introduced and the performance of two common windows,i.e.,cross window and rectangular window are compared with the actual data.According to the multipath phenomenon of the target in the close range of the radar in complex environments,an improved CFAR is proposed to solve the false alarm problem caused by multipath.(3)The principles of Kalman filtering and extended Kalman filtering are briefly introduced,and the influences of filtering parameters are analyzed by simulations.The NNDA algorithm is briefly introduced and the PDA algorithm formula is derived.Based on the NNDA algorithm,a near-neighbor range and velocity data association algorithm is proposed for the one transmitting and two receiving antenna system to conquer the angle jitter problem,and the actual data is used for comparison and verification.