UAV guidance law for ground-based target trajectory tracking and loitering

A pursuer UAV tracking and loitering around a target is the problemanalyzed in this work. The UAV is assumed to be a fixed-wing vehicle and constant airspeed together with bounded lateral accelerations are the main constraints of the problem. The pursuer motion control law proposed in this paper is based on the definition of an oscillatory motion created by a center of oscillation: it allows the pursuer UAV for the fulfillment of the requirements of target tracking under the stated constraints. In particular, the center of oscillation tracks the real motion of the target and the UAV tracks the center of oscillation by means of a suitable guidance law. In this work a description of the mathematical model of the problem, the oscillatory motion and the guidance law is provided. Proofs of stable closed loop behavior are given. Simulation results are finally shown and commented.