NOVEL SWITCHING CONTROL OF THE BALL-SCREW DRIVEN STAGE FOR NANO POSITIONING

摘要

A ball-screw driven stage is broadly used because of its simple mechanism, high stiffness and low cost. The ball-screw stage, however, has the limited performance caused by the ballscrew friction that is nonlinear and varies as the position of the stage changes. [1, 2] Many researchers have proposed methods to resolve the friction problems for precision positioning systems. Generally, precision control of positioning stage requires that accurate model of friction and system identification. [3, 4, 5, 6] These control methods have the difficulty of applying to the industry area because of the complexity of the friction model and the parameter identification.