Nonlinear Multirate Model-Algorithmic Control. 2. Experimental Application to a Polymerization Reactor

Abstract

This paper experimentally implements the nonlinear multirate model-algorithmic controller to regulate the reactor temperature, which is measured at a fast sampling rate, and the number-average molecular weight of the polymer, which is measured at an extremely slow sampling rate. A detailed model of the continuous free-radical methyl methacrylate polymerization reactor was developed from first principles to construct the multirate controller algorithm. The performance of the controller was examined by varying the tunable controller parameters, where it was shown that the controller can adequately track step changes in the output set points under active input constraints. Decreasing the tunable controller parameters deteriorated the control of the number-average molecular weight but improved the control of the temperature. Overall, the nonlinear multirate controller was an efficient and effective method to deal with the difficult problem of multirate output measurements.