On stabilization of nonlinear systems with enlarged domain of attraction

Abstract

This paper presents a systematic procedure to design a control law that guarantees asymptotic stability of an equilibrium with an enlarged domain of attraction for a class of nonlinear systems. To this end, we use a natural extension of well-known linear time-invariant transformation methods to write the system in controller canonical form with a forcing term. The control law is implemented in two steps, first we calculate a nonlinear state feedback that cancels the nonlinear terms of the unforced system, so that for the resulting system a suitable Lyapunov function candidate is available. Then, we add a linear state feedback that stabilizes the equilibrium and maximizes its domain of attraction. Interestingly enough, the latter maximization problem reduces to a classical, linear time invariant H∞ minimization problem. An example is given to illustrate the procedure.