Sampled data observer design based inter-sample output predictor for Electro-Hydraulic Actuators systems

In this paper, a Sampled Data Disturbance Observer (SDDOB) which estimates simultaneously the unmeasurable states and the uncertainties for the EHA systems is presented. The novelty of our approach is the use of an inter-sample output predictor which allow the users to increase the frequency acquisition of the piston position sensor without affecting the convergence performance. The stability analyses of the proposed observer is proved using Lyapunov function adapted to hybrid systems. To show the efficiency of the SDDOB, numerical simulations of a control application which combines the SDDOB and a PI controller for the purpose of piston position tracking problem is presented.