Differential flatness based nonlinear predictive control of fed-batch bioreactors

A trajectory optimization scheme based on the property of differential flat ness is proposed in this paper. A dynamic optimization problem is transform ed into a lower dimensional nonlinear programming problem through the use o f flat outputs. This optimization approach is demonstrated in the repeated optimization of nonlinear dynamic systems under feedback in an approach sim ilar to nonlinear model predictive control. This approach is illustrated on two examples involving biomass optimization and product optimization. Opti mization under feedback is studied for the nominal problem and the case whe re uncertainty is present. The proposed scheme is also used in conjunction with a nonlinear Luenberger observer to generate the optimal trajectories u nder parametric uncertainty. (C) 2001 Elsevier Science Ltd. All rights rese rved.