Abstract
The efficient transportation by overhead cranes needs fast and accurate positioning, but residual vibration which prevents positioning accuracy generally tends to be induced by fast transportation. In previous paper, we proposed a control method which is based on the characteristic that the residual vibration is completely suppressed in a linear undamped system when excited by an external force which does not contain the natural frequency component of the system. To apply this characteristic to nonlinear damped systems, we defined the apparent external force which includes the influence of system nonlinearity and damping. Furthermore, a robustness improvement method against the estimation error of the natural frequency was proposed, and its effectiveness was verified by numerical simulations. In this paper, we verify the effectiveness of the robustness improvement method by experiments. The experimental apparatus consists of a trolley driven by a belt along a straight rail and a rigid rod coupled to the trolley at its upper end. Experiments demonstrate that this control method can suppress the residual vibration if there is no estimation error, and the robustness against the estimation error can be improved by the robustness improvement method.
