Mixed ℋ ₂ /ℋ ∞ approach to fault-tolerant controller design for Lipschitz non-linear systems

This study is concerned with the design of fault-tolerant controller for Lipschitz non-linear continuous-time systems in the presence of disturbances and noises. The simultaneous estimation of actuator faults and states is formulated as a mixed ℋ2/ℋ∞ control problem. The fault-tolerant controller is then designed to compensate for the effect of the faults by stabilising the closed-loop system and guaranteeing a prescribed performance level in the presence of disturbances. This design problem is reduced to a linear matrix inequality feasibility problem and a constructive algorithm is proposed. Two examples are presented to demonstrate the performance of the proposed fault-tolerant control scheme.