An LMI approach to mixed H1/H∞ robust fault-tolerant control design with uncertainties

This paper studies mixed H₂/H_infin robust fault-tolerant control for a class of uncertain systems and its application to flight tracking control. A sufficient condition is derived by introducing some important auxiliary variables, which guarantees that the uncertain closed-loop system is robustly stable and satisfies the mixed H₂/H_infin constraint in both normal and fault cases. In the framework of linear matrix inequality (LMI) approach, a multi-objective optimization problem is solved with much less conservative via an iterative algorithm. Simulation results obtained with a nonlinear fighter aircraft model show the effectiveness of the proposed method.