USE OF PIECEWISE-LINEAR CONTINUOUS OPTIMAL-CONTROL FOR TIME-DELAY SYSTEMS

By using piecewise linear continuous control, rather than piecewise co nstant control, excellent control can be obtained with the use of a re latively small number of stages. For nonlinear systems, the use of a m ultipass method in iterative dynamic programming (IDP) is convenient a nd effective in obtaining convergence to the optimum. However, a good initial control policy, which can be readily obtained by the use of Ta ylor series approximation and piecewise constant control, may be neces sary. Computational experience with a two-stage CSTR system shows the viability of using IDP for typical chemical engineering systems with t ime delays.