An Ultraprecision Aerostatic Guideway Controlled by Active Inherent Restrictors

提出了一种改善超精密定位系统中空气静压导轨性能的主动控制方法。该方法采用主动固有限流器(空气)来控制导轨上的气动压力。作者发明的空气由一个带有通孔的压电致动器组成，当致动器嵌入受控导轨时，通孔的一端足够小以起到小孔的作用。工作台由空气静压导轨导轨组成六个气圈；四个气圈用于补偿垂直位移，两个气圈用于补偿水平位移。微型计算机根据传感器检测到的工作台位移，改变压电作动器的长度，以控制空气的孔口面积，补偿位移。在垂直和水平两个方向上都证明了导轨的刚性可以是无限的，工作台的运动直线度可以达到20 nm左右，而没有出现气锤。研究了空气对金刚石调谐的影响，利用空气对安装在工作台上的铝合金进行了调谐，改善了加工表面的粗糙度。

An active control method for improving the performance of an aerostatic guideway used in an ultraprecision positioning system is proposed. The proposed method employs an Active Inherent Restrictor (AIR) to control pneumatic pressure onthe guideway. The AIR invented by the authors consists of a piezoelectric actuator having a through hole, one end of which is small enough to function as an orificewhen the actuator is embedded in the guideway to be controlled. Six AIRs are incorporated into the table guided by the aerostatic guideway ; four AIRs for compensating the vertical displacement, and two for the horizontal displacement. According to the table displacements detected by sensors, amicro computer changes the length of the piezoelectric actuators for controlling the orifice area of the AIRs, and for compensating the displacements. In both vertical and horizontal directions, it was provedthat the stifness of the guideway can be infinite, and the straightness of motion of the table can beabout 20nm, while the pneumatic hammer did not occur. The effect of the AIR on diamond tuning is also shown ; an aluminum alloy mounted on the table controlled by the AIR was tuned, and the roughness on the machined surface can be improved.