Supervisory chaos control of a two-link rigid robot arm using OGY method

In this article, we have proposed a new approach for controlling a two-rigid link robot arm which has been chaotic by applying an external periodic input. The whole system includes a plant, chaos controller and a supervisor. Supervisor chooses suitable external input by using some chaotic criteria such as ldquoLyapunov Exponentrdquo and ldquoBifurcation Diagramsrdquo. Chaotic control of the plant involves two steps, finding unstable periodic orbits (UPOs) of the system by ldquoPoincare maprdquo, and using a control technique in order to stabilize a desirable orbit. OGY method has been utilized as chaos controller. Moreover, the supervisor selects suitable UPOs as intermediate goals in order to guide the plant and OGY controller in the chaotic attractor to reach to the target orbit. By using this method, the chaotic behavior of the system turns to a certain periodic behavior and speed of control enhances in contrast to OGY method.