Flatness-based Target Tracking for a Quadrotor Unmanned Aerial Vehicle

In this paper we propose a flatness-based moving target tracking strategy for a quadrotor unmanned aerial vehicle (UAV). The objective is to drive the quadrotor as fast as possible to track the target whose position and velocity information are discontinuous without violating system constraints. A simple version of the dynamical system obtained from a suitable coordinate transformation of the Euler - Lagrange model is applied to avoid the system singularities. Based on flatness and exact tracking error linearization, a dynamic feedback solution to the tracking trajectory problem is presented. This controller will push the quadrotor to chase the target along the time-optimal trajectory until the new target information comes. The reference trajectory can be obtained by solving a constrained optimization problem which is formulated by means of flatness approach.