8 September 2011 The theoretical basis of the moiré fringe signal quality detecting by observing the figures
Author Affiliations +
Abstract
The moiré fringe signal quality decides the precision of the encoder. In the production process of RESR, usually, the moiré fringe signal quality is detected by the Lissajou graphs observing by the oscilloscope. Lissajou graph is the common method for analyzing the dc level of two analog signals, the amplitude of alternating current, the phase of signal, the relation of frequencies and other parameters. It is convenient, intuitive, and would not be affected by the rate; furthermore, it applies to be used for field detection. The ideal moiré fringe signal has two sine signals which phase difference is 90°, and prefect round Lissajou graph. However, in practice, for a variety of factors, moiré fringe photoelectric signal has dc level, higher harmonic, orthogonality deviation, equal amplitude deviation, and so on; that is why Lissajou graph will appear offset or distortion. So we can observe the shape's deviation of the Lissajou graph in order to judge the signal deviations. This paper introduces the diameter deviation to describe deviation between the Lissajou graph of actual signal and the Lissajou graph of ideal signal, establishes the mathematical model of diameter deviation, and theoretically analyzes the relationship between the diameter deviation and the parameters of moiré fringe photoelectric signal. Using the VB6.0 simulation software to prove the results of the theoretical analysis, we find that the simulation results agree with the previous detection, which supply theoretical foundation for the observation of Lissajou graph. After analyzing the character of the encoder's signal when the encoder works in a uniformly accelerated motion, we point out the applicative conditions of the observation of Lissajou graph detecting moiré fringe signal. The conclusions of this paper have important significance for detecting the signal quality of encoder, and have certain reference value for detecting other signals.
© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Jie Yi, Jie Yi, Li-min An, Li-min An, Chun-xia Liu, Chun-xia Liu, } "The theoretical basis of the moiré fringe signal quality detecting by observing the figures", Proc. SPIE 8191, International Symposium on Photoelectronic Detection and Imaging 2011: Sensor and Micromachined Optical Device Technologies, 81912F (8 September 2011); doi: 10.1117/12.902477; https://doi.org/10.1117/12.902477
PROCEEDINGS
7 PAGES


SHARE
Back to Top