Control Performance of Two-Stage Positioning System (Comparison of Positioning Performances with Four Kinds of Control Methods)

摘要

As a high precision positioning system with a long working range and high speed, a two-stage positioning system has been proposed. However its most suitable control method has not been clarified yet. The purpose of this research is to clarify the most suitable control method for the system theoretically and experimentally. An experimental two-stage positioning mechanism in this paper comprises a ball screw mechanism as a coarse motion one and the piezo-driven mechanism as a fine motion one. This paper first, describes the basic control system configuration and four kinds of controllers designed for the system : the PID, the state feedback, the sliding mode and the H_∞ controllers. And then the positioning performances with their controllers are examined experimen- tally, and theoretically. The results show the PID control system to perform well generally though no control system has better performance on all the benchmark tests discussed in the paper than the others.