Precise open-loop positioning using LPM with error correction

  • Furuhashi, Hideo (Department of Information Network Engineering, Aichi Institute of Technology) ;
  • Shingu, Hiroyasu (Department of Electrical Engineering Aichi Institute of Technology) ;
  • Hayashi, Niichi (Department of Mechanical Engineering Aichi Institute of Technology) ;
  • Watanabe, Shigeo (Department of Electrical Engineering Aichi Institute of Technology) ;
  • Sumi, Tetsuo (Department of Electrical Engineering Aichi Institute of Technology) ;
  • Uchida, Yoshiyuki (Department of Information Network Engineering, Aichi Institute of Technology)
  • Published : 1995.10.01

Abstract

A precise open-loop positioning system using linear pulse motor has been developed. The system is operated in a microstepping mode by controlling the electric current. One step of 508 .mu.m (tooth pitch of the linear pulse motor) is divided into 508 micro-steps equally. The displacement is measured with a system using a Fiezeau-type interferometer. Periodical positioning error with a period of the tooth pitch was observed in this system. Therefore, the position is corrected using the error. The error is stored into computer in advance, and the microstep current is corrected on basis of the stored data. Although the positioning error of the system without the correction was .+-.4.5 .mu.m, that with the correction was decreased to .+-.1.0 .mu.m.