An adaptive observer for sensor fault estimation in a class of uniformly observable non-linear systems

Abstract

Based on the techniques of high gain observer and adaptive estimation, an adaptive observer is proposed in this paper for sensor fault estimation in a class of uniformly observable non-linear systems. It is first assumed that a high gain observer exists for the fault-free system. With a parametric model of sensor fault, a high gain adaptive observer is then designed for sensor fault estimation. In order to establish the global convergence of the adaptive observer, in addition to the usual conditions for high gain observer convergence, a persistent excitation condition is also required, like in most recursive parameter estimation problems.