Comparing Equivalent Dead-Time Compensators

Abstract: The paper deals with evaluation of some new aspects in dead-time compensators design for the first order time delayed plant. It considers several alternative solutions to the Smith predictor employing higher order low pass filters. Nominally they should yield the same dynamics. Evaluation by real time control of an Arduino based thermal plant aims to show if they are equivalent also in non-ideal practical applications. Another tested question is, if the introduction of higher order filters brings some advantages. Due to introduction of a disturbance reference model, the new modifications of the Smith predictor keep its original dynamics also under an explicit stabilizing controller. They may be derived both for input and output measurable disturbances. However, since a disturbance observer for reconstruction of non measurable output disturbances by a parallel plant model is applicable just to stable plants, from the beginning the comparison shows non identical properties of the treated solutions. The carried out experiments show also their differences in noise attenuation.