Suboptimal control and stability of nonlinear discrete-time systems

In this paper suboptimality bounds and stability of nonlinear discrete-time infinite-horizon controllers are investigated. The nominal plant is suppos ed to be controlled by means of a feedback control law which is optimal wit h respect to some given criterion. The use of the Taylor-Maclaurin formula appears to be the key to establish the suboptimality properties of the dece ntralized control and at the same time to derive upper and lower bounds on the suboptimality. (C) 2000 The Franklin Institute. Published by Elsevier S cience Ltd. All rights reserved.