Research on Vibration Effect of Ultraprecise Optical Encoder for Micro/Nano Measurement

Abstract

Optical encoders have been used for decades as displacement measuring devices. As far as image measurement is concerned, CCD and CMOS are gradually used in metrology fields. In practice, performance of image ultraprecise optical encoders are related to environmental temperature, humidity, data processor speed, and vibration, thus measurement precision of encoders will be affected, and these factors limit their usage scale. Among these factors, the vibration is the largest effect factor. Here, a new experiment system was built to study vibration effect of measurement. Experiments indicated that the effects of vibration mainly exist in two aspects. Firstly, vibration induced deformation of glass grating, so distance of adjacent grating lines got uncertain. Secondly, random vibration affected CMOS image sharpness, and it reduced accuracy of encoding and decoding. Finally, some methods are provided to reduce the vibration of the grating encoder.

High-speed measurement method for 2D surface roughness of aircraft conduit connector

“…(2) The impact on the stability of the coordination. For clearance fit, due to the unevenness on the micro surface of the workpiece, the fit gap gradually increases during the working process, which affects the fit properties; For interference fit, the micro peaks and valleys may be smoothed out during the assembly process, resulting in a low actual effective interference and reducing the connection strength of the workpiece [4][5][6][7][8] (3) The impact on fatigue strength. For most mechanical parts, they are mostly in a state of metal fatigue, which refers to the phenomenon of material rupture under alternating stress.…”