Theoretic study on new method for roll angle Measurement of Machines

Against the measurement for the roll angle of coordinate measuring machine and machine tools used the linear guide, based on the optical principle of optical components to linearly polarization light, a new and simple method for the roll angle measurement is proposed, in which a half wave-plate is used as sensitivity part. If the stage has a roll angle with respect to the reference base, it can be obtained from the differential intensity of two light beams from the polarization beam splitter. According to the optical structure and electric structure of the measurement system, the measurement model of the roll angle sensor is established and the measurement error of it is analysed by Jones matrix. It is proved through the theoretical analysis that the roll angle measurement system proposed has some advantages: the simple and compact structure, high-resolution. Because of being a non-contact measurement method, the method is suitable for the roll angle measurement of the long-distance precision guide.