Predictor-based control design for UAVs: robust stability analysis and experimental results

Abstract

This paper proposes predictor-based controllers for a class of linear time-varying systems with input delay, model parameter uncertainty, and delay uncertainty. Sufficient conditions for global asymptotic stability are given in terms of linear matrix inequalities. The class of systems considered corresponds to two problems relating to the control of unmanned aerial vehicles. An inner–outer-loop control structure is assumed with the delay appearing in the outer-loop variables involving the vehicle's translational degrees-of-freedom. The first control problem considered is output tracking for the position of the vehicle. The second problem is visual servoing where camera measurements are used to control the vehicle's pose relative to a visual target. The effectiveness of the proposed controllers are shown via simulation. Experimental validation is performed using an indoor quadrotor platform at the Applied Nonlinear Control Lab (ANCL), University of Alberta.