A robust Smith predictor modified by internal models for integrating process with dead time

The internal model principle and control together (IMPACT) structure of the Smith predictor is proposed. The structure constructively achieves both the robust stability and absorption of external disturbances. In the structure design, the absorption principle is applied to enable the rejection of arbitrary class of deterministic disturbances and/or to suppress the effects of low frequency stochastic external signals on the system output. It is shown that the tuning of IMPACT structure is extremely simple due to relatively small number of tuning parameters all having clear physical meanings. The presented results of the simulation runs demonstrate the design procedure and illustrate the efficiency of the structure in disturbance absorption.