A theorem on existence of neighbouring trajectories satisfying a state constraint, with applications to optimal control.

This paper deals with the implementation of a predictor control law and the suboptimal digital redesign for a continuous-time plant with a delayed input. It is shown that the closed-loop eigenvalues of the delayed system designed via a predicted-state feedback controller are identical to those of the non-delayed system with the same gain matrix based on the non-predicted state feedback. Thus, the well-developed design methods of linear quadratic regulators for continuous-time non-delayed systems can be indirectly applied to delayed-input systems. Moreover, for practical implementation by digital computer, we derive a suboptimal digital redesign of the delayed-input system using the predictor control.