Multivariable Nonlinear Control of a Continuous Polymerization Reactor with Singular Characteristic Matrix: An Experimental Study

In this experimental work, the globally linearizing control (GLC) method is implemented on a micro-computer to control conversion and temperature in a continuous stirred tank reactor by manipulating the reactor residence time and two coordinated heat inputs. Conversion is inferred from on-line measurements of density and temperature. A key feature of the control problem is that its characteristic matrix is generically singular. Singularity of the characteristic matrix is handled by using a dynamic state feedback. The performance of the controller is evaluated in terms of its ability in performing a fast and smooth reactor start-up and tracking set-point changes in the presence of active input and state constraints.