A descriptor system approach to nonlinear singularly perturbed optimal control problem

This paper considers the infinite horizon nonlinear quadratic optimal contr ol problem for a singularly perturbed system which is nonlinear in both, th e slow and the fast variables. The relationship between this problem and th e analogous one for a descriptor system is investigated. Parameter-independ ent controllers are constructed that solve the problem for the descriptor s ystem and lead the full-order system to the near-optimal performance. Estim ates on the closeness of the cost under near-optimal controllers to the opt imal one are obtained. (C) 2001 Elsevier Science Ltd. All rights reserved.