Research on large time-delay system based on online identification of Smith predictive control

HU Su-hong， FANG Jian-an
（Institute of Science and Technology，Donghua University， Shanghai 201620，China）

Abstract： The large time-delay is often existent in industrial processes. In order to solve the problem of difficult to control without accurate system model during the long time-delay control， an online identification of Smith predictive controller for a system with the long time-delay was proposed. Combined the Smith predictive control with online identification，the tradition system model in Smith predictive control was replaced by system identification model which utilized recursive least-square to identify the various parameters of the model. The results of simulation for the second-order plus pure delay model objects with or without error in the lag time show that the online identification of Smith predictive control has the best performance indexes and better robustness.
Key words： Smith；second-order plus pure delay；online identification；predictive control