抄録
Demands for three-dimensional nano-positioning are increasing in a wide range of industries. In order to meet such demands, it is necessary to realize a stable long-stroke vertical nano-motion. In long-stroke vertical motion control, the minimization of gravity load is one of the most important issues. In addition, it is important to minimize error factor from nonlinear phenomenon such as friction, vibration and heat transfer. In general, however, it is difficult to support gravity load of the moving part and to ensure that the vertical motion platform is free from such error factors which may occur during its nano-positioning. In this study, therefore, a novel vertical motion platform with a noncontact counterbalancing mechanism is developed for achieving long-stroke vertical nano-motion. The developed platform is characterized by a noncontact drive with a voice coil motor, by levitation with aerostatic guideways, by a counterbalance with noncontact vacuum cylinders, by an overall structure made of ceramics and by a symmetrical structural configuration. The positioning performance of the developed platform is evaluated through a series of vertical positioning experiments. The experimental results demonstrate that the developed platform has a superior positioning performance.
