Robust NSV fault-tolerant control system design against actuator faults and control surface damage under actuator dynamics

Abstract

In this paper, a decentralized fault-tolerant control (FTC) system is proposed for near-space vehicle (NSV) attitude dynamics. First, NSV reentry attitude dynamic models with an uncertainty, actuator failure models, and a control surface damage model are described. Next, a new local fault identification algorithm is proposed to identify different types of actuator faults, which is based on multiobserver techniques. The local fault identification is constituted by a fault detection observer, fault parameter identification observers, and a decision-making mechanism. Then, a global adaptive sliding-mode observer is used to design the command filter backstepping faulttolerant controller. Our focus is on the accommodation for actuator faults, control surface damage, uncertainties, and the resulting disturbances of the NSV. Finally, simulation results are given to demonstrate the effectiveness and potential of the proposed FTC scheme.