Hybrid Adaptive Fault-Tolerant Control for Compound Faults of Hypersonic Vehicle

Abstract

This study investigates the hybrid fault-tolerant control (FTC) for hypersonic flight vehicles (HFVs) under the rudder structure fault (RSF) and rudder angle deviation fault (RADF). The nonlinear equations of the model are linearised by fuzzy logic, the external nonlinear disturbance is approximated by radial basis functions, which transforms the classical HFV into a linear system. In the case of only a RSF, the state feedback system can passively shield the fault using a compensation function and design a threshold to create conditions for RADF detection. During the RSF and RADF compound faults, the system with an adaptive observer implements angle deviation fault isolation/estimation and shields the structural fault. By using the estimation results, active-passive hybrid compensation completes passive FTC of the structural fault and active FTC of the angle deviation fault. The adaptive learning rates that mimic animal predatory behaviour increase the sensitivity to incipient deviation of RADF and improve compensation. Lyapunov method proves the stability and semi-physical simulation shows the control efficiency.