A sligthly improved robust adaptive observer for actuator fault detection

In this paper, we address the problem of actuator fault detection and estimation for a plant in the presence of external disturbances. We design a robust fault estimation technique based on an adaptive observer with enhanced speed of adaptation. The construction of the observer is carried out through a transformation of the plant model into its special coordinate basis (SCB) form. This transformation allows a decoupling of the fault estimates from the disturbances. Thanks to this decoupling, the standard adaptive observer is slightly modified to achieve faster fault estimation in presence of disturbances and plant-model uncertainties. Simulation experiments are presented to illustrate the effectiveness of the proposed adaptive scheme.