COMPARISON BETWEEN TWO FRICTION MODEL PARAMETER ESTIMATION METHODS APPLIED TO CONTROL VALVES

Friction in the control valve is one of the major sources of oscillations and abnormal operations in process control loops. Models of control valves can be used to diagnose abnormal operations as well as to compensate for such undesirable effects. This work describes two methods used to estimate the parameters of a Karnopp friction model applied to control valves. The methods were tested using simulated data of three valves with different friction levels. The advantages of each one are emphasized.