New Measuring Scale of CMMs

摘要

In order to get high precision, low-cost and high anti-interfere performance measuring scale of CMMs, this paper, on the basis of metrological grating, introduces the metrological grating with nano measurement precision, which is based on two times Moire fringe. The basic principle is that two indicated gratings, which are fixed on the same measuring base scale, move relatively to the scale grating thus produce two groups of one time Moire fringes, two groups of lens are used to adjust the moving direction of the two groups of the one time Moire fringe to be opposite, therefore the two groups of one time Moire fringes interfere with each other and produce two times Moire fringe. By subdivision of the two times Moire fringe and through simulation calculation the resolution of the grating can achieve 5.40 x 10~(-10)m, and the measurement precision can achieve nanometer. Besides, this paper analyses the grating's principle error, the grating scribing error, the light source error and the adjusting error of optical system, and discusses the methods of compensation and correction of these errors.