Reliable H∞ Aircraft flight controller design against faults with state/Output feedback

Abstract

This paper presents a novel H∞ formulation to design a reliable tracking controller for a discrete LTI aircraft system against actuator outage faults and control surface impairment modelled as polytopic uncertainties. Both the state-feedback and output-feedback cases are considered. The approach is based on multiobjective optimization using several parameter dependent Lyapunov functions, each corresponding to a vertex of the uncertainty polytope. The main advantage of this approach with respect to the other well-known techniques is the reduced conservativeness. In the output-feedback case, a new Linear Matrix Inequality (LMI) formulation is derived and solved by an iterative LMI (ILMI) algorithm. Finally, the application to a nonlinear F-16 aircraft model with actuator outage faults and control surface impairment illustrates the effectiveness of the proposed approach. © 2005 AACC.