Multi-Objective Fault-Tolerant Output Tracking Control of a Flexible Air-Breathing Hypersonic Vehicle

Abstract

This paper deals with the problem of multi-objective fault-tolerant output tracking control for the longitudinal model of a flexible air-breathing hypersonic vehicle (FAHV). There exist some challenges for control design for the vehicles due to the inherent couplings between the propulsion system, the airframe dynamics, and the presence of strong flexibility effects. This paper addresses the problem of guaranteed cost fault-tolerant output tracking control with regional pole constraints against actuator faults for the FAHV system. A non-linear longitudinal model is adopted for control design because of the complexity of the FAHV systems. First, a linearized model is established around the trim point including the state of altitude, velocity, angle of attack, pitch angle, and pitch rate, etc. for a non-linear, dynamically coupled simulation model of a FAHV with the aim to address the multi-objective fault-tolerant output tracking control problem. Second, the control objective and models of actuator faults are presented. Third, by utilizing the Lyapunov functional approach, a multi-objective analysis condition is proposed in terms of convex optimization problems, that can be easily solved via standard numerical software. Then, a multi-objective fault-tolerant controller is designed such that the resulting closed-loop system is asymptotically stable and satisfies a prescribed performance cost with the simultaneous consideration of poles assignment in spite of possible actuator failure. Finally, the simulation results are given to show the effectiveness of the proposed method, which is verified by an excellent altitude reference and velocity tracking performance.