Application of an Adaptive Pole-Zero Placement Controller to Chemical Processes with Variable Dead Time

Abstract

An algorithm for providing adaptive control and dead time compensation of single input-single output systems with unknown or varying dead time is presented. The algorithm is designed by pole-zero placement and is unique in that an explicit estimate of the dead time is not required, thus avoiding a difficult estimation problem. Parameter estimation for the adaptive controller/dead time compensator is performed with a recursive least squares algorithm. Simulation studies and experimental application on a heat exchange loop on a pilot scale distillation column verify the performance of the algorithm. In each example, the performance of the adaptive controller/dead time compensator is compared to that of a proportional plus integral controller, illustrating the improvement in performance obtainable with the adaptive algortihm.