Active fault tolerant control design for UAV using nonsingular fast terminal sliding mode approach

Abstract

In this paper, an active fault tolerant controller is proposed for the unmanned aerial vehicle (UAV) attitude control system using nonsingular fast terminal sliding mode control technique. Firstly, the nonlinear attitude dynamics model of UAV with actuator faults and external disturbance is described. Next, a neural network-based fault estimation observer is designed to obtain the estimated value of unknown actuator faults and external disturbance, and the stability of the designed observer is also proved. Then, an active fault tolerant controller is designed based on the fault estimation observer and nonsingular fast terminal sliding mode control technique. The Lyapunov stability analysis shows that the proposed fault tolerant controller can guarantee the finite time asymptotic stability for nonlinear closed-loop attitude control systems of UAV with actuator faults and external disturbances. Finally, numerical simulation results are presented to illustrate the benefit of the proposed scheme.