Active fault-tolerant tracking control for near-space vehicle attitude dynamics with actuator faults

Based on both adaptive and fuzzy logic techniques, the fault-tolerant tracking problem for near-space vehicle (NSV) with actuator faults is investigated in this paper. First, the nonlinear NSV attitude dynamics is given, which can represent the dynamic characteristics of NSV in both ascent and re-entry phases. The actuator fault under consideration in this study is the loss of effectiveness, and a novel fault detection scheme is presented by designing a nonlinear fault detection observer. In terms of fault detection information and multi-observer technique, a fault isolation scheme is proposed. Taking advantage of a fuzzy logic system (FLS) to approximate the unknown nonlinear function, an adaptive FLS-based fault-tolerant tracking control law is developed to achieve asymptotic output tracking and closed-loop stability of NSV attitude dynamics in spite of the actuator faults. Simulation results are provided to illustrate the feasibility of the proposed fault-tolerant tracking control approach.