Modeling and fuzzy controller design for ACR polymerizing-kettles

Temperature control of polymerizing-kettles is the key part of ACR (Acrylate Copolymer Resin) production. However, it is very complex to create a mathematical model for the polyreaction process; the modeling remains a difficult task in polyreaction engineering. In this paper, qualitative characteristics of emulsion polyreaction mechanism are analyzed, and with the statistic characteristic on how polymerization speed varies with transformation rate, the analytical model of ACR polymerizing-kettles is created, which turns out to be a nonlinear time-varying system with time delay. For this kind of plant, we design a parameter-self-tuning fuzzy controller based on Smith predictor and carry out two kinds of simulation experiments on different conditions: one with invariant system parameters and the other one with time-varying ones. Compared with the conventional control method, the results demonstrate that the control method proposed in this paper is good at interference resisting and effective for precise temperature control of the polymerization.