Decentralized Anti-Windup Compensator Designs for Small Unmanned Aerial Vehicles

This thesis studies the design and implementation of anti windup compensators for UAVs with magnitude and rate saturated actuators. The focus is on two types of UAVs; a Quadrotor UAV and a Fixed wing UAV. Decentralized anti-windup compensators are designed to address the problem of magnitude saturation in Quadrotor UAVs. The developed anti-windup compensators are founded on an LMI-based approach previously used in literature to provide global stabilty guarantees with some level of performance guarantees. The work on the decentralized anti-windup compensators for Quadrotor UAVs are further improved on by replacing the use of LMIs in the determination of the anti windup compensator parameters with approximate linear based guidelines after a Lure-Postinikov Lyapunov function is used to provide global stability guarantees. This approach applies not only to Quadrotor UAVs but also to a wide class of systems that contain double integrators. The developed anti-windup compensators were designed and implemented for an experimental Quadrotor UAV where both simulation results and flight test results clearly show the ability of the anti-windup compensators to reduce the effect of magnitude saturation in Quadrotor UAVs. Finally, the thesis describes the design of decoupled multivariable anti-windup compensators to tackle the problem of rate saturation on a fixed wing UAVs. Simulation results obtained demonstrate that these anti-windup compensators are capable of managing the system responses during periods of rate saturation.