ROBUST STABILITY CONSIDERATIONS IN OPTIMAL-DESIGN OF DYNAMIC-SYSTEMS UNDER UNCERTAINTY

This paper presents a method for the incorporation of robust stability criteria in the design of dynamic systems under uncertainty. Process systems are modelled via dynamic mathematical models, variations inclu de both uncertain parameters and time-varying disturbances, while cont rol structure selection and controller design is considered as part of the design optimization problem. Stability criteria are included, bas ed on the concept of the measure of a matrix, to maintain desired dyna mic characteristics, in a multiperiod design formulation. A combined f lexibility-stability analysis step is also introduced to ensure feasib le and stable operation of the dynamic system in the presence of param etric uncertainties and process disturbances. The potential of the pro posed approach is illustrated with a ternary distillation column desig n and control problem (featuring a rigorous tray-by-tray model). (C) 1 997 Elsevier Science Ltd.