固有振動数成分除去法による天井走行クレーンの残留振動抑制

Abstract

An overhead traveling crane is widely used at factories, and it plays an important role in the mass transportation system. The main trouble in operation of the overhead traveling crane is that the residual vibration of a cargo often occurs at the end of motion. In addition, the development of the automatic operation system of the overhead traveling crane is desired for an efficient and safe transportation. In this research, a new type of open-loop control method has been proposed for suppressing the residual vibration. This method is based on the dynamical property that the residual vibration does not occur in a linear undamped system when it is excited by an external force which does not involve any component of natural frequencies of the system. The authors have applied this property to a nonlinear damped system and developed an efficient method to derive an adequate trajectory of the trolley of the overhead traveling crane which enables complete prevention of the residual vibration of the cargo. However, there remains a problem that the trolley turns back and the cargo swing largely during transportation. To reduce the rapid velocity change of the trolley throughout the transportation, this paper proposes an optimization method to design the trajectory of the trolley. The trajectory consists of Fourier series and is designed by using the method of Lagrange multiplier. By numerical simulation result, this method also reduce the angular displacement of the cargo during the transportation.