Dynamic Displacement Measure of Friction Twister Roller Guider with Nanometer Resolution Grating System

摘要

High resolution and long range of displacement can be generated through the friction twister roller guider (FTRG ). The resolution of FTRG is in nanometer level, and the displacement range extends to several hundred millimeters. So the capacity and inductance micrometer that possess measure range of several millimeters cannot complete the measure task of FTRG. Commonly, the laser interferometer and the grating interferometer are utilized to do this job. In this paper, a novel grating system is constructed to test the dynamic characteristics of FTRG. To acquire high precision result in optical displacement measuring, the signal quality of moire" fringes must be kept reliable and constant. So several adaptive processing methods to enhance the signal quality of moire" fringes are provided in this paper. The process platform is based on SHARC (Super Harvard Architecture Computer) DSP and flash sample technique. At last, the result of the test is listed to show the effects of the optical system and the algorithms in digital signal processor. After combining the counting algorithm, subdivision algorithm and adaptive filters together , the qualities of the signals are highly enhanced. The synthesized phase figures of two original signals are given , which show that the adaptive filters can eliminate the drift, stabilize the amplitude, and improve the orthogonal of the signal. So the measure results get precise and reliable.