A practical approach based on stream of variation for positioning accuracy in precise linear motion stage

Abstract

a tanghaocsu@csu.edu.cn Keywords: positioning accuracy; stream of variation; precise linear motion stage. Abstract. This paper introduces a new analyzing approach on positioning accuracy (PA) in precise linear motion stage (PLMS). As one of the most important parameter, PA is affected by several reasons for the quality of PLMS, such as machining error, assembly error and controller accuracy etc. Conventional method only focuses on one aspect leading to positioning error (PE), which is not systematically and comprehensively. By adopting new analyzing approach, it is obviously understandable how errors from each part in PLMS give impact on PA and how PE accumulates. In this paper, the measuring result of PA is studied firstly. Then related factors affecting PA are concluded through analyzing characters in the measurement result of PA such as fluctuation, repeatability uncertainty and backlash. A series of analysis leading to these factors are introduced, including motor output, screw and assembly error, and an error model for PA in PLMS is established. A case study of one PLMS based on the new analysis procedure is developed, and corresponding experiments are carried out to collect the data. For one PLMS, this new approach on PA is not only beneficial for error compensation, but also helpful in design part. Furthermore, it is a systematic approach in PA analyzing procedure, which is also a new way to weigh PA in PLMS.