抄録
For the purpose of improving productivity, auto conveyance machines like fork lift are introduced as a part of production system and enlarged ones are required to shorten its task time. In this case, the input not considering the dynamics of the machine excites the vibration of the fork and the vibration affects fast positioning. Moreover, in lifting motion, fork lift has time-varying characteristics due to the existence of load mass on the fork. To solve this problem, a methodology on the basis of nonstationary robust control theory is proposed in this paper. The uncertainties of controlled object and load mass are included in the generalized plant and time-varying frequency weightings are designed to consider the change of natural frequency. By use of this proposed method and a two-degree-of-freedom control method as a comparative approach, the effectiveness of the proposed method is verified through the experiment.
