Abstract
In this research, we consider a three-link underactuated manipulator, whose first link is actuated and second link and third link are not actuated. According to the previous our research on two-link underactuated manipulator, we analytically investigate nonlinear dynamics and by using high frequency excitation of first link, we clarify through bifurcation analysis that the free links can be swung up and are stabilized at some configurations without state feedback of free joint.
