FRICTION MODEL PARAMETER ESTIMATION FOR CONTROL VALVES

This paper presents a method to estimate offline the parameters of the friction model of Karnopp, applicable to a control valve. The method is simple and easy to use. It is presumed that the valve is submitted to a triangular shape input signal and that the stem position and the actuator pressure are measured. The results are fairly good. It is possible to estimate the three friction coefficients (viscous - Fv , Coulomb - Fc and static - Fs ), the mass m of the moving parts of the valve and the coefficient k of the spring.