Modification of an adaptive observer to improve its performance in actuator fault detection

In this paper, we address the problem of actuator fault estimation for continuous linear time-invariant system in the presence of external disturbances. Based on an adaptive observer, the Robust Adaptive Fast Fault Estimation observer (RAFFE) is designed to enhance speed actuator estimation. The construction of the proposed observer is carried out through transformation of system into its Special Coordinate Basis (SCB) form. This transformation allows, in first stage, a decoupling of the fault estimates from the disturbances. Thanks to this decoupling, the observer produce a robust fault estimation based on a modified form of the standard adaptive observer. Simulation results are presented to illustrate the efficiency of the proposed RAFFE methodology.