Further results on the design of an observer for an electro-hydraulic actuation system with deadzone nonlinearity

Abstract

In this paper we present further results on the design a non-linear observer for estimating the null current in an electro-hydraulic actuation system. In previous work it was shown that the observer achieves ultimate boundedness of the observation error based on results on the stability of control loops with slope restricted non-linearities. In this work we give a complete characterisation of the asymptotic convergence of the observation error considerably tightening the results obtained earlier.