Scientific paper ID 650 : 2012/1

We study in this paper the complex behavior of double inverted pendulum with a vertically oscillating suspension point. The system of interest is derived as a model of concrete mechanical phenomena. The equations representing this model are nonlinear ordinary differential ones and are treated as nonlinear dynamical system. The results show that stability of inverted state depends from amplitudes of oscillation of suspended point. Bifurcation diagrams are found which locate regions of periodic and quasi-periodic motion within the parameter space of the system.