The Molecular Weight Control Based On Square-root B-spline Model And Rational Square-root B-spline Model

The molecular weight distribution(MWD) control is systematically analyzed and studied in this paper using the stochastic distribution control(SDC) theory.First the modeling of the static and dynamic squre root B-spline model is proposed.With the model set up prior and a selected performance index,the control sequences are synthesized so as to make the output probability density function(PDF) trace the target distribution.Then a new approach to the modeling of the PDF rational square root B-spline model of the dynamic stochastic system is proposed based on the analysis of the relationship between the actual weight of square root model and the pseudo-weight in the rational square root B-spline model.Based on the rational squre root B-spline model,two control algorithms are obtained respecticely.The results are applied to the MWD modelling and control of a polymerization process.Laboratory-scale styrene bulk polymerization process of molecular weight distribution is studied.The results show the effectiveness of the proposed scheme.