Vision based target tracking/ following and estimation of target motion

Abstract

The vision based target tracking/ following is presented. There is no interior communication between the target and tracker and their relative displacement is measured with the 3D visual sensors. The tracking/ following control law is designed in the half North-East- Down (NED) frame with the dynamic inversion and the robust perfect tracking (RPT) techniques. The half NED frame is formed by moving the origin of the NED frame to the mass center of the target and then rotating the X axis along the Z axis to be aligned with the flight direction of the target. The RPT technique is one of the better techniques to design the tracking control laws for the linear plants. It involves with the high-order derivatives of the reference to improve the tracking/ following performance. In order to implement the RPT control law, a novel algorithm is developed to estimate the velocity and acceleration of the target with the measured relative displacement between the target and tracker. The algorithm is developed based on the extended Kalman filtering and under assumption of the quasi steady states in which the derivatives of the target ground speed, flight path and directional angles are constant. The simulation results demonstrate that the resulting the closed-loop system is capable of tracking/ following the 3D maneuvering target in the scheduled relative distance and orientation with respect to the target.