Modelling and LPV control of an electro-hydraulic servo system

This paper aims to show the modelling and control of an hydraulic servo system, targeting at frequency domain based controller design and the implementation of a LPV controller. The actual set-up consists of a mass, moved by a hydraulic cylinder and an electro-hydraulic servo valve. A nonlinear parametric model of the system, a number of fitted linear black box models as well as a LPV model combining these fits have been determined. In discretization of the control strategies for implementation on a digital control system, a new discretization algorithm is derived for LPV structures. Simulations and experimental results indicate the potential benefits of a position dependent controller over a classical controller, but show the limitations as well