Ultra-Precision Linear Motor Positioning Technique
Masanori Suematsu*, Takao Fujii*, Atsushi Kawahara*, Tomoaki Tanimoto*, Toshio Matsumoto* and Hideaki Watanabe**
*Research Laboratory, Yaskawa Electric Corporation.,2-1, Shiroishi, Kurosaki Yahata-Nishi-Ku, Kitakyushu-shi, Japan
** Robot Division, Yaskawa Electric Corporation
This paper introduces an ultra-precision linear motor positioning technique. In order to realize a compact positioning movement without dual structure consisting coarse and fine positionings, higher accuracy air slider studies are conducted on a completely frictionless support mechanism using a linear motor and an externally pressurized air bearing. Results are as follows: (1) Temperature rise of 03°C, table displacement of 0.16μm and guide warp of 0.03μm are achieved by slider guide with adiabatic structure. (2) To reduce cogging force and normal force, coreless and slotless motor is developed. Thrust ripple has reduced to less than 2 % of the rated thrust. (3) Maximum pulse velocity of 10 Mpps, acceleration of 3M/S2, 0.2 sec for 15mm stroke are achieved. (4) Software servo system using DSP is adopted, positioning accuracy of 10nm are achieved without fine positioning.