Smart relay-based online estimation of process model parameters

Abstract

This paper presents online estimation of unstable and integrating time delay process model parameters using a smart relay. The describing function (DF) approximation of relay not only results in simpler analytical expressions but also enables one to estimate the model parameterswith significant accuracy. Measurement noise is an important issue during estimation of process model parameters. The smart relay is capable of emulating the dynamics of a conventional relay and also of rejecting the ill effects ofmeasurement noise. Simulation results show the usefulness of the identification technique.