Fast Robust Adaptive Backstepping Control with Its Application to Fault-Tolerant Flight Envelope Protection

Abstract

In this paper, a fast robust adaptive backstepping (FRAB) flight envelope protection controller is proposed to deal with nonlinear aircraft system with partial loss faults in structure. Firstly, the nonlinear longitudinal dynamics model of a large transport aircraft is built up. Secondly, a FRAB controller using fast terminal sliding mode and radial basis function neutral network (RBFNN) is designed to track the pilot’s command. Furthermore, two protection schemes of command limiting and control mode switching are proposed to implement the flight envelope protection task in this study. Simulation results of the Boeing 747 airplane model show that the proposed algorithm has robust stability and better performances in overshoot, settling time, and steady error compared with conventional backstepping methods. The effectiveness of the developed algorithm for flight envelope protection has been validated through simulation with model uncertainties, disturbances, and structural faults.