Estimation of the Most Critical Parameter for the Two-Movement Method to Compensate for Oscillations Caused by Control Valve Stiction

Abstract

The two-movement method is one of the most effective compensation methods to remove oscillations caused by control valve stiction in feedback control loops. This method requires one critical parameter $m_{\mathrm{ ss}}$ for implementation, namely, the value of controller output associated with the desired valve position. This brief proposes a novel approach to estimate this critical parameter solely based on the oscillatory data samples available in the control loop. This approach removes the requirement of extra experiments before the implementation of the two-movement method such as open-loop step responses in the existing studies and greatly reduces the time cost of two-movement method. Numerical and laboratory examples are provided to illustrate the effectiveness of the two-movement method incorporating the estimation of $m_{\mathrm{ ss}}$ .