UAV Localization And Tracking Based On Microphone Array

With the popularization of UAV technology,UAVs are widely used in agriculture,surveying and mapping,detection and aerial photography,etc.But the wide application also introduces more problems: criminals use UAVs to photograph sensitive areas.Such as civilian airports and military installations.Monitoring of UAVs is particularly important to ensure the safety of sensitive areas.This thesis studies the real-time positioning,tracking and monitoring of UAVs using microphone arrays,and implements a 128-channel microphone array on the hardware platform to test the monitoring performance.The main contributions of the thesis are as follows:1.Several localization algorithms based on the microphone array are analyzed,including the estimation of the azimuth and pitch angles of the target to the microphone array,and the method of measuring the distance of the target by moving a single station.Through the Doppler frequency shift generated when the UAV moves,a method for determining the UAV distance based on the difference between the receiving frequencies of different channels and different times is improved.The above algorithms are compared and analyzed by simulation and verified.2.The analysis shows that the basic Kalman filter cannot complete the tracking of the UAV,because the motion observation equation of the UAV is nonlinear.By introducing the frequency state information of the UAV,the pseudo-linear algorithm is used for nonlinearization,and the equation is solved to obtain the target state estimation result.Tracking the target by increasing the frequency information of the UAV can overcome the limitation that the pure azimuth tracking requires the observation station to make effective maneuvers.3.Design 128-channel microphone array and data receiving system,use change chip to complete the conversion and collection of microphone collected data;use FPGA board to control the system,responsible for data preprocessing and transmission.In addition,the software design scheme is introduced,and the user interface,the overall framework and functional modules of the software are expounded.4.By designing experiments,the microphone array is calibrated.The detection distance of the microphone array was tested in a quiet and noisy environment.The test results show that the array can monitor the UAV within a certain range.By dividing the grid points,the UAV is hovered at the point,and the positioning accuracy of the UAV is tested.The results show that the accuracy meets the requirements.Finally,this thesis tests the performance of the system by flying the UAV outdoors to verify the function of the system.The test results show that the system can track the UAV well under a relatively good signal-to-noise ratio,which has a certain practical value,which proves the feasibility of using the acoustic system to monitor the UAV.