Design And Verification Of Guidance Law For UAV Coordinated Tracking Ground Target

Automatic tracking of ground targets is one of the important applications of UAVs.It has wide application prospects in military and civil fields,and has very important theoretical significance and engineering value.In this dissertation,a fixed-wing UAV is taken as the research object.The guidance law of UAV's over-flight tracking and standoff tracking are respectively designed based on the differential geometry theory,and a cooperative guidance law is proposed based on Leader-Follower formation mode.The premise of this dissertation is that the control system of the UAV inner loop has been designed and can respond well to the guidance commands of the outer loop.Meanwhile,there is a ground moving target indicator system(GMTI)can obtain the location,heading,speed and other status information of ground targets.First of all,the two modes of over-flight tracking and standoff tracking are analyzed and modeled in this dissertation.Using the 2-D form model combined with Frenet-Serret frame of the differential geometry curve theory,3DOF mathematical model of over-flight tracking and standoff tracking were built.Based on this,UAV's over-flight tracking and standoff tracking guidance law are respectively designed and completed the stability analysis.Matlab/Simulink simulations are completed for static,uniform linear and variable direction of a ground target respectively.Finally,the guidance law of two tracking mode is in a unified form,for being applied to different tracking objects.Secondly,based on the stand-alone tracking guidance law,the guidance problem of multiple UAVs coordinated standoff tracking a ground target is studied.A new cooperative tracking guidance law for multi-UAVsby Leader-Follower formation is proposed.The cooperative tracking strategy is adopted to make the speed and heading angle of Follower UAVs gradually close to Leader UAV,and the problem of traditional limit distance tracking mode for ground target speed range is solved.Finally,the stability analysis of the guidance law is completed by Lyapunov stability theory and simulation verification of Matlab/Simulink is carried out.Finally,based on the UAV stand-alonereal time simulation verification environment in the laboratory,the remote control software and the two-dimensional track display software is developed which is applicable tomultiple UAVs.Besides,the flight control software,six degrees of freedom model software and simulayion control platform are adapted to upgrade.Based on the above software,a simulation environment of multi-UAV tracking ground target guidance law is built,which verifies the feasibility and rationality of the designed guidance law in the real-time simulation of UAV six degree of freedom nonlinear model.