NON-LINEAR STATE ESTIMATION WITH TIME-DELAYED MEASUREMENTS IN POLYMERIZATION PROCESSES

GALDEANO, RUBÉN; ASTEASUAIN, MARIANO; SÁNCHEZ, MABEL

Costa Rica

Simposio; XII Simposio Latinoamericano de Polímeros (SLAP 2010) - X Congreso Iberoamericano de Polímeros (CIP 2010); 2010

Universidad de Costa Rica

The measurement and control of polymer processes is a very challenging task due to their high nonlinearity, strong relationship between quality variables and process conditions, and the absence of reliable on-line sensors. In these processes many important variables cannot be measured on-line or can only be measured at low sampling frequencies. In this context, state estimation becomes an important step for the proper implementation of control systems.A particular feature affecting the control of polymer processes is that critical quality variables are usually measured off-line, or on-line but with a considerable analysis time. This introduces significant delays in the availability of the measurements, which have to be taken into account by a proper state estimation method.In this work we present the implementation of a two-time scale Unscented Kalman Filter applied to a polymerization process, capable of handling on-line and off-line time-delayed measurements. The process selected as case study is the copolymerization of methyl methacrylate and vinyl acetate in a continuous stirred tank reactor.