Structure Design of Large Travel One-Arm Bridge Type Z-Axis Nano-Positioning Stage

Abstract

In some areas such as micro-mechanical, ultra-precision machining, nanotechnology, the high-precision positioning and very fine vertical scanning motion are needed urgently. Therefore, the Z-axis micro-displacement driving control technology has become the key technology in these areas. The piezoelectric ceramics actuator and stepper motor were integrated into hybrid linear actuator in Z-axis nanopositioning stage, and this can simplify the structure of the drive system. By calculating the gravity center of the vertical scanning system, and using single counterweight, a new one-arm bridge type structure was built. Appropriate tension and current sensors were also equipped in order to real-time monitor the drive status. It is feasible to balance the weight with this simplified system structure, and also guarantee the driving control accuracy of nanopositioning stage. Besides, in the structural design, the Abbe error can be reduced greatly by placing the stage center, grating ruler and displacement measurement centerline on the same line with grating reading head. The driving travel of nanopositioning stage is 150mm, and driving resolution is 1nm. The designing method introduced gives a scientific method and practical reference for the development of z-axis driving control system.