Sequential synthesis of a robust multi-loop pid controller for a reactive distillation column

A sequential synthesis procedure for decentralized (multiloop) PID controllers based on the estimation of control loops interaction in the form of multiplicative plant uncertainty is proposed. The paper shows that each synthesis iteration is accompanied by the correction of robust performance criteria for the coupled SISO systems. The results of industrial application of the proposed sequential design to a reactive distillation unit are discussed and the comparative analysis with other techniques is included.