| The rapid development of UAVs has brought convenience to people’s daily life,but also brought many safety and privacy concerns.In this context,the real-time detection and tracking of UAVs has become a hot research field.Based on LFMCW phased array system,this paper focuses on the key technologies of small UAVs target detection and tracking.The hardware development and software debugging of signal processing are completed,and the radar field test proves the effectiveness of the system for UAVs detection.The main work can be divided into four parts:In this context,starting from radar detection technology,combined with LFMCW system and phased array technology,this paper aims at the real-time detection and tracking requirements of UAVs throughout the day.In this paper,the signal processing system of phased array radar based on the LFMCW system is designed and implemented.The main work is divided into four parts:1.The design scheme of radar signal processing system is introduced.Firstly,the radar system architecture is briefly introduced,and the structure design of the TMA phased array system adopted in this paper is given.The advantages and disadvantages of LFMCW symmetric triangle wave and sawtooth wave are analyzed,and the principles of distance measurement and speed measurement are also analyzed.According to the application scenario of radar monitoring UAVs,the system signal processing scheme is established.Aiming at the fuzzy problem of radar Angle measurement,the phase sum difference method is proposed to solve the fuzzy problem.To take advantage of phased array,two search tracking modes TWS and TAS are used to detect and track multiple targets.2.According to the overall design of radar signal processing system,LFMCW phased array radar signal processing hardware platform based on ZYNQ architecture is designed.The hardware design of each part of ZYNQ signal processing system platform is introduced in detail,including the circuit design of data acquisition,data storage and communication.3.The paper introduces the whole signal processing flow of radar signal processing system.The algorithm involved in the signal processing process is simulated and verified,including MTD algorithm,CFAR algorithm,two-dimensional FFT ranging and speed measurement algorithm,etc.Aiming at the strong clutter interference in CFAR algorithm,a two-dimensional CFAR algorithm was proposed to improve the detection probability.Secondly,the aggregation algorithm of the center of mass method and Kalman filter algorithm are used to eliminate outliers and regularize target points,and complete the estimation of target parameters at the next moment.4.The whole radar system to carry out the field experiment verification.The function of distance measurement,speed measurement and Angle measurement for multiple targets is realized.Furthermore,the accurate search and tracking function of radar to multiple targets in TAS and TWS mode is further tested.The test results show that,the designed LFMCW phased array radar signal processing system can realize the detection and search of multiple targets and target tracking and meet the design requirements. |
