CONTROL OF CONSTRAINED MULTIVARIABLE NONLINEAR PROCESS USING A 2-PHASE APPROACH

A computer-based algorithm is presented for the control of complex process units which are characterized by difficult features such as nonlinear input/output relationships, multivariable nature, operational constraints, imprecise models, and inadequate measurements. A two-phase algorithm is proposed to deal with these difficult features in a direct manner. The algorithm makes use of approximate process models which take into account significant physical and chemical events in the process. The first phase of this algorithm consists of identifying unmeasured disturbances and the parameters and states of the approximate model using measurements from the immediate past.