A feedback-based implementation scheme for batch process optimization

The terminal-cost optimization of a control-affine nonlinear system leads t o a discontinuous solution that can be characterized in a piecewise manner. To implement such an optimal trajectory despite disturbances and parametri c uncertainty, a cascade optimization scheme is proposed in this paper, whe re optimal reference signals are tracked. Optimality is achieved by the app ropriate definition of reference signals (input bounds, state constraints, or switching functions) to track in various sub-intervals. Furthermore, con servatism is introduced into the optimization problem to ensure satisfactio n of path constraints in the presence of uncertainty. Finally, the proposed cascade optimization scheme is illustrated on a simulation of a fed-batch penicillin fermentation plant. (C) 2000 Elsevier Science Ltd. All rights re served.