Researches On State Estimation Of UAV Formation In Target Tracking Process

In the process of UAV formation tracking the moving target on the ground,the UAV can only detect the target's relative motion state by radar,vision and other sensors.If UAVs of the formation want to estimate the target's motion state,it must accurately estimate the motion state of itself.Each UAV in the formation is regarded as a moving sensor node,and the communication link of the formation is regarded as the communication topology of the sensor network.In this paper,the problems of state estimation of UAV formation target tracking are studied deeply.Under the condition of switching topologies,a distributed information-weighted Kalman consensus filter?IKCF?is proposed,and an improved low-pass consensus filter is given for filtering the measured motion accelerations of the target.Thus,the dynamic performance of the estimation of the IKCF is improved.In addition,the switched linear system of estimation errors is derived.The switched linear system is proved to be globally uniformly asymptotically stable?GUAS?with a weighted l₂-gain.Consequently,the convergence of the estimation errors is given.A federal Kalman filtering algorithm of attitude anti-interference integrated navigation is proposed by fusing the information of Micro-Electro-Mechanical Strapdown Inertial Navigation System?MEMS-SINS?,Global Positioning System?GPS?,magnetometer,solar vector?SV?.In order to eliminate the influence of the disturbing magnetic field observations on the attitudes of pitch and roll angles,a method of correction update for yaw angle component in quaternions using the magnetometer is designed,and an Euler angle information fusion method is developed by constructing a pseudo-covariance matrix of Euler angels in fusion update of the filter.A method of solving the least-squares unit solar vector and the adaptive least-squares unit solar vector is proposed by employing the output currents of the photovoltaic array.Thus,when there are some faults or manufacture errors in the photovoltaic array device,the solved solar vector still has higher accuracy and fault tolerance.In order to verify the effectiveness of the algorithm,a physical device of the photovoltaic array is designed and manufactured.In addition,the solved unit solar vector is used to assist the navigation system for attitude estimation.