Five Degrees of Freedom Simultaneous Measurement of Linear Motion System by Combination of Optical with Inclination Sensors

Linear motion system is widely used in precision machine tools, semiconductor manufacturing equipment and other high-end precision equipment. Due to the high kinematic accuracy, accurate and efficient measurement method is necessary in assembly to assure high quality and efficiency of high-end precision equipment. A measurement method combining optical with inclination sensors to simultaneously measure five degrees of freedom of linear motion system is proposed. The optical path is analyzed in the measurement of each degree of freedom. The laser drift is then separated and compensated by a proposed common optical path structure. Based on the kinematic error model, the decoupling method of angular and translation errors is analyzed to eliminate the coupling and Abbe errors. Experiments are carried out to verify the compensation of laser drift and the accuracy of the proposed measurement system by comparing with laser interferometer and electronic level measurement results. The maximum differences of pitch, yaw, rolling rotation errors and horizontal, vertical translation errors between these measurement systems and the proposed system are 5.55", 4.28", 2.21", 2.47 μm and 1.92 μm, respectively. This system with simple structure and low cost can be highly accurately and efficiently used in the measurement of linear motion system. © 2021, Editorial Office of Journal of Xi'an Jiaotong University. All right reserved.