A geometric error measurement system for linear guideway assembly and calibration

Abstract

Geometric errors, such as straightness, perpendicularity, and parallelism errors are determinant factors of both the accuracy and service life of a linear guideway. In this study, a multipurpose geometric error measurement system was mainly composed of a laser source and an in-lab-developed optical module is proposed. Two adjustment methods were used for the in-lab-developed optical module to calibrate the altitude angle of the pentaprism: The first one is designed for ease of operation based on Michelson principle using a laser interferometer as the light receiver, and the second is aimed at high calibration repeatability based on the autocollimator principle using the quadrant detector (QD) to replace the light receiver. The result shows that the residual errors of the horizontal straightness and the vertical straightness are within ±1.3 μm and ±5.3 μm, respectively, when referred to as the commercial laser interferometer. Additionally, the residual errors of perpendicularity and parallelism are within ±1.2 μm and ±0.1 μm, respectively, when referred to as the granite reference blocks.