Fault-tolerant control of an aerial manipulator with guaranteed tracking performance

In this article, a fault-tolerant control (FTC) scheme of an aerial manipulator is proposed, which can guarantee the transient and steady-state tracking performance under actuator faults. A novel performance function (NPF) with simple form and explicit terminal time is designed to constrain the tracking errors. First, backstepping technique combined with the NPF is adopted as control framework to guarantee the asymptotic stability. Then, adaptive nonsingular terminal sliding mode with estimated actuator faults is used as the robust controller to deal with actuator fault. Finally, extended state observer is used to estimate and compensate complex coupling effects between the main-body UAV and loading manipulator, and external disturbance. The stability of the aerial manipulator system with actuator faults and external disturbance is proved by Lyapunov analysis. Besides, the effect of the turbulent wind field on the body of the vehicle is analyzed. Several comparative simulations are carried out to show the effectiveness of the proposed FTC scheme.