Fault Diagnosis and Active Fault Tolerant Control for Near Space Vehicle Based on Adaptive Observer

In this paper, Takagi-Sugeno (T-S) fuzzy modeling for Near Space Vehicle (NSV) is first introduced. The nonlinear dynamics of NSV are represented by a T-S fuzzy model. The fault diagnosis and active fault-tolerant control (FTC) problems for NSV with actuator fault are then investigated. An adaptive fault diagnosis observer (AFDO) is designed to detect and estimate fault. The residual is defined as the norm of the output error between AFDO and actual system to detect the actuator fault, and an adaptive fault estimation algorithm is proposed to estimate the fault. An active fault tolerant controller is designed by utilizing the diagnostic fault information to compensate for the loss of actuator effectiveness. Finally, simulation results on the longitudinal model of NSV are presented to demonstrate the efficiency of the proposed approach.