A study on a linear-driven ultraprecision gas bearing stage with electrorheological fluid damper

With the increasing demands for higher accuracy and higher productivity of the ultraprecision equipments, Ultraprecision gas bearing stage systems driven by linear motors become research hotspots. To overcome the demerits of the kind of stages such as the low positioning stability due to outer disturbances etc., an Electrorheological shear damper suitable to an established linear driven gas bearing stage system has been developed. Through an experimental identification, the ERF damper nonlinear characteristics under high electric fields were obtained based on an Eyring constitutive model, which has a smooth transition from preyield to postyield region. Furthermore, the models and controllers of the stage under three conditions of without ERF damper, with zero electric filed ERF damper (E=0kv/mm), with high field ERF damper (E≫0kv/mm), have been developed. The experiment results verify that the developed ERF damper can largely improved the performances of the ultraprecision stage.