Adaptive Trajectory Tracking Control of a Quad-rotor System Based on Fuzzy Monitoring Strategy

The paper addresses the problem of trajectory tracking control of a quad-rotor system, aiming to improve the performance of path tracking and obtain a better "adverse factors" rejection property. In response to a hybrid effect that external disturbance, inertia parameters uncertainty and control input constraints coexist in a dynamic system, an adaptive compensated controller with back-stepping technique is proposed. The designed control system can compensate for errors caused by the hybrid effect without the need for an accurate model. Furthermore, a fuzzy monitoring strategy is introduced to improve adaptive ability of the closed loop control structure and achieve better transients. Adaptive laws in the control system are derived by Lyapunov stability analysis such that the trajectories of tracking error converge to a small neighborhood of equilibrium point. Finally, simulation results are discussed to demonstrate the effectiveness of the proposed control method.