A study on nanometer positioning table system equipped with electrorheological fluid units

With the increasing demands for higher accuracy and higher productivity in the manufacturing, environment, ultraprecision table positioning technology of nanometer order is urgently required. In order to meet these requiremen ts, it is necessary and indispensable to develop the ultraprecision table s ystems of noncontact type, which is constructed from an aerostatic guideway and a linear motor. However, such a table system of noncontact type has lo w performances in the positioning stability and the disturbance response, b ecause of friction free and low damping capacity in the guideway. In this s tudy, therefore, a linear motor-driven ultraprecision aerostatic table syst em equipped with electrorheological fluid (ERF) units has been developed. F urthermore, it has been verified that the developed ERF units are effective and applicable to simultaneously achieve quick-response and nanometer posi tioning accuracy.