An improved parameter-dependent approach to robust optimal fault estimation for helicopter model

This paper proposes a parameter-dependent approach to robust fault detection and estimation problem for linear time-invariant (LTI) systems. The unknown input, actuator faults, sensor faults and disturbances are considered in our design. Through projection lemma, we provide a sufficient affine matrix inequality for the integrated system in order to achieve robust performance criterion. In stead of obtaining the optimal solution by quadratic approach, we have used a parameter-dependent lyapunov approach which aimed at eliminating the involved coupling between system matrices and the lyapunov matrices; hence the conservativeness due to quadratic approach can be dramatically reduced. We present a design example in which we apply our method to a helicopter model.