On methods of treating DC levels in an adaptive digital Smith predictor

Abstract

Two popular methods of treating unknown or slowly varying DC levels in the input and output measurements used for parameter estimation in an adaptive digital Smith predictor are studied. They are the high-pass filtering method and the method of estimating an additional constant. The performance of the former is found to be inferior in that it leads to a larger output variance under a stochastic environment. This is caused by the higher variation in model output due to static gain variations in the estimated explicit model.