Error analysis on the roll angle measurement of machine tool's guideway

To evaluate the influence of incident angle error of the reflector on the roll angle measurement of machine tool's guideway, a new mathematical model was established by Jones matrix method. The new model takes the influence of the incident angle error of high-reflectivity mirror into consideration based on the existing model. The reflected light of the mirror with different incident angles was analyzed based on the action mechanism of multiple dielectric films. Then the influence of incident angle error of reflector on the roll angle measurement was calculated. Results showed that the measurement gain coefficient varied with the incident angle and a maximum value of 720 was obtained when the incident angle was 36-deg, a 6-fold increase compared with previous results. In the experimental setup, we measured a gain coefficient of 346 at the 38-deg incident angle to the mirror. A roll angle measuring resolution 0.1-arcsec was attained using a phase meter with a resolution of 0.01-deg. The theoretical analysis of the new model was verified, which also provides a measuring sensitivity enhancement approach by carefully controlling the incident angle of the mirror. © 2016, Editorial Office of Journal of Xi'an Jiaotong University. All right reserved.