An Unmanned Aerial Vehicle Autonomously Tracking Ground Moving Targets: Algorithm And Experiments

It has been full of practical and theoretical significance in both civilian and militaryareas to effectively use unmanned aerial vehicle (UAV) to perform missions forinstance ground target tracking. Under the circumstance, this dissertation focuses on theproblem of a single ground target tracking with a UAV. In the dissertation, target statesestimation, real-time guidance and control of the UAV are the two key aspects of theresearch. Both the main work and the contribution are summarized as follows:(1) Factors that influence the UAV target tracking are analyzed, and a frameworkto the problem is presented.Formulation on the problem of UAV target tracking is achieved by thecomprehensive analysis on the mission process. In detail, the main characteristics ofmission are analyzed, meanwhile, the factors including UAV platform and groundmoving target are considered and modeled respectively. Afterwards, a usefulframework is established for the single UAV target tracking problem.(2) A Current Statistics (CS) model and Constant Velocity (CV) model basedInteracting Multi Model Unscented Kalman Filter (IMM_UKF) is proposed toestimate the target states.Considering tracking a moving ground target, a CSM is used to describe themaneuvering. To improve the robust of the target tracking filter, a CV model isintroduced to be interacted with the CS model. The CV model describes thenon-maneuvering of the target. Meanwhile UKF is used to solve the non-linearmeasurement problem. The proposed algorithm is proved effective by the simulationresults and experimental results.(3) A separate guidance law and a heading rate control law are proposed.In order to control the UAV to track the ground target persistently and safely, Aseparate guidance law and a heading rate control law are proposed. The model of theproblem is established. Exposure avoidance and minimizing the exposure time arestudied respectively in terms of the initial state of the UAV. Afterwards, the proposedapproach is extended to deal with a moving target. Finally, theoretical analysis,simulation results and experimental results demonstrate the effectiveness of theproposed approach.(4) An experimental system for UAV tracking a moving ground target is designed.The proposed solving framework and algorithms to this problem is demonstrated withthe experimental system.To demonstrate the solving framework and algorithms presently proposed, anexperimental system is designed, which includes a fixed-wing UAV and otheressential hardware. The experimental system achieves the function of target detecting and positioning, sensor control, target state estimation and UAV guidance.