A nonlinear optimal control method is developed for magnetostrictive actuators used to actively attenuate plate vibration. Significant improvements in vibration control can be achieved when the magnetostrictive actuators are driven at moderate to high field levels. This results in nonlinearity and hysteresis which cannot be effectively compensated using linear control theory. This issue is addr...

We study synchronization of nonlinear systems that satisfy an incremental passivity property. We consider the case where the control input is subject to a class of disturbances, including constant and sinusoidal disturbances with unknown phases and magnitudes and known frequencies. We design a distributed control law that recovers the synchronization of the nonlinear systems in the presence of ...

Many real-world systems contain uncertainties and with time-varying delays, also, they have become larger and more complicated. Hence, a new decentralized variable structure control law is proposed for a class of uncertain large-scale system with time varying delay in the interconnection and time varying unmatched uncertainties in the state matrix. The proposed decentralized control law for the...

Abst rac t -A concept of exact slow optimal control is defined for a general class of nonlinear singularly perturbed systems utilizing the slow manifold theory. Under a set of conditions an exact optimal feedback regulation restricted to the slow manifold is obtained. The result is applied to a class of nonlinear systems with nonlinear fast actuators. It is shown that by adding an extra compens...

We present a practical stability result for dynamical systems depending on a small parameter. This result is applied to a practical stability analysis of fast time-varying systems studied in averaging theory, and of highly oscillatory systems studied by Sussmann and Liu. Furthermore, the problem of practically stabilizing control affine systems with drift is discussed.

In this paper suucient second order optimality conditions are established for optimal control problems governed by a linear elliptic equation with nonlinear boundary condition, where pointwise constraints on the control are given. The second order condition requires the coercivity of the Lagrange{function on a suitable subspace together with rst order suucient conditions on a certain set of str...

We prove the existence of optimal control for nonlinear systems having implicit derivative with quadratic performance criteria.