Vibration Control of a Rotary Crane by Elimination of the Natural Frequency Component

Abstract

In the situation where the crane operator population is decreasing, development of techniques for efficient crane operations is desired. One of the means to make them efficient is the automation, where the challenge is how to suppress the residual vibration. In order to deal with this problem, the authors proposed a new type of open-loop control method for suppressing the residual vibration by eliminating natural frequency component. This method is based on the fact that residual vibration is completely suppressed in a linear undamped system excited by an external force that does not contain the natural frequency component of the system. This paper applies the method to the control of a rotary crane model consisting of an arm which rotates in the turning and the derricking directions, and a cargo suspended from the arm. In order to examine the effectiveness of the proposed method, numerical simulations are conducted for three cases of crane operations. The results show that the proposed method is able to move the arm to the target position, preventing the residual vibration of cargo in all cases considered.