CONTROL OF NONLINEAR DIFFERENTIAL-ALGEBRAIC-EQUATION SYSTEMS WITH DISTURBANCES

This paper addresses the control of a class of nonlinear, multivariabl e, high-index differential-algebraic-equation systems with external di sturbances. Initially, an algorithmic procedure is developed to derive an equivalent state-space realization of the constrained system, vali d for arbitrary disturbances. Then, on the basis of the derived state- space realization, a feedforward/feedback controller is developed to c ompletely eliminate the effects of the measurable disturbances and ind uce a well-characterized input/output behavior in the constrained syst em. The application of the proposed control methodology is illustrated on a high-purity absorption column.