THE STUDY ON POSITION ACCURACY OF MICRO-COORDINATE MEASURING MACHINE

In order to measure the microcosmic profiles of ultra-smooth surfaces, a high-accuracy noncontact micro-Coordinate Measuring Machine (micro-Coordinate Measuring Machine, micro-CMM) is developed in this paper. The working table of this measurement device is located by a macro-micro dual-drive system. A closed-loop control system, which is composed by a laser interferometer and stepper motors, is adopted to improve the positioning accuracy of the macro-positioning stage. The experimental results show that the positioning accuracy of this system is obviously improved and satisfies the positioning requirement of the macro-positioning stage. Because the positioning accuracy of the flexure-based micro-positioning stage can not satisfy the design requirement under the control of the traditional PID control, A PID control system based on Adaptive Neural-Fuzzy Inference is proposed to improve the control accuracy of the micro-positioning stage. The experimental results show that this system can improve the positioning accuracy of the micro-positioning stage, and basically meets the requirement of the design.