The modeling and parameter identification of the hydraulic proportional valve

The effective orifice area is introduced for modeling an electric-hydraulic proportional valve in paper. A second-order difference equation is adopted to describe the relationship between the effective orifice area and the input signal. The ordinary least square method is used to identify the valve model parameters, and the Householder transfer is used to solve the ill-conditioned matrix equation. An experimental hydraulic circuit is constructed on the FESTO platform and parameters of valve model are identified with the experimental data. It is proved that the method presented in this paper is effective and valuable.