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

- The proposed observer allows continuous state and disturbances estimation between the sampling times.
- The exponential convergence of the SDDOB is proved using a Lyapunov approach adapted to impulsive systems.
- The proposed SDDOB allows permits to increase the EHA position sensor acquisition frequency without affecting the convergence of the observer.
- The proposed observer serves as a base for the future output feedbacks controllers to improve the tracking performance of the EHA system.

In this paper, a Sampled Data Disturbance Observer which simultaneously estimates the unmeasurable states and the uncertainties for the Electro-Hydraulic Actuators systems are presented. The novelty of our approach is the use of an inter-sample output predictor which allows the user to increase the frequency acquisition of the piston position sensor without affecting the convergence performance. The stability analysis of the proposed observer is proved using the Lyapunov function adapted to hybrid systems. To show the efficiency of the proposed observer, numerical simulations of a control application which combine the proposed observer and a Proportional Integral controller for the purpose of piston position tracking problem are presented.