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 supposed to be controlled by means of a feedback control law which is optimal with respect to some given criterion. The use of the Taylor–Maclaurin formula appears to be the key to establish the suboptimality properties of the decentralized control and at the same time to derive upper and lower bounds on the suboptimality.