Abstract
Chaos is a bounded unstable dynamic behavior that exhibits sensitive dependence on initial conditions and includes infinite unstable periodic motions. This article examines the controlling of a chaotic system via optimal control technique which is based on the Pontryagin minimum principle. A 3D chaotic system is considered to apply this scheme which have 5 equilibrium points. Finally, numerical simulations are presented to demonstrate the effectiveness of the proposed method. The simulation results illustrated the stabilized behaviour of states and control functions for different equilibrium points.