Intelligent counting method of interference fringes

Abstract

The invention discloses an intelligent counting method of interference fringes. The intelligent counting method comprises the following specific steps of: filtering random impulse noise from the data acquired by a linear array charge coupled device (CCD) sensor by adopting a self-adapting median diffusion filtering algorithm; reducing Gaussian noise by using a non-linear diffusion filtering algorithm; determining the reference range of effective data of the interference fringes, wherein the maximum gray value point Max, the minimum gray value point Min and the threshold value T are calculated, and the threshold value T refers to the point of which the gray value changes most in the determined reference range of the effective data; and performing second order derivation on a curve which is determined by an effective data range, and judging the changing state of the interference fringes according to second order derivative numerical value changes so as to realize automatic counting of the interference rings. By using the method, a diffusion median filtering algorithm is used for performing filtering denoising on the acquired data, the changes of the interference rings are further judged by judging the second order derivative numerical value changes in the effective reference range in real time, and the counting stability is promoted.

Description

technical field [0001] The invention relates to the counting of interference rings, in particular to an intelligent counting method of interference fringes based on an embedded linear array CCD. Background technique [0002] When using Michelson interferometer for macro measurement, it is necessary to accurately calculate the number of changing rings of the interference ring. The traditional method is to use manual counting, that is, the human eye directly observes the interference fringes imaged on the screen, and the human hand gently rotates the fine handwheel , each time a ring is changed, it is manually recorded once, and the interference fringes that "emerge" or "submerge" need to be counted for each measurement. This method is simple to operate and does not require additional measuring equipment except the Michelson interferometer, but it is only suitable for counting small numbers of interference rings. In actual operation, it is often necessary to record more than a...

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Problems solved by technology

But there are also the following disadvantages: this method is too strict on the placement of the device, and the thickness of the stripes will also change as the measurement progresses, and the position of the device needs to be continuously adjusted as the measurement progresses, which increases the complexity of the actual operation sex

Disadvantages: In terms of data processing, the threshold value is the median value of the sum of the maximum and minimum values ​​of the data, which has a certain error; the mean filtering algorithm used cannot maintain the characteristics of the real image; the designed Michelson interference fringe counter is based on PC machine platform, the mobility is relatively poor; the level of intelligence is not high enough

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