Method for accurately extracting unknown phase shift amount based on optimized quantum particle swarm algorithm

Abstract

The invention relates to a method for accurately extracting an unknown phase shift amount based on an optimized quantum particle swarm algorithm. The method comprises the following steps: firstly, approximately calculating a Fresnel diffraction field statistical average value of each phase shift amount in four-step phase shift based on statistical properties of a diffraction field; secondly, solving an intermediate value according to a phase random condition, and representing an approximate phase shift quantity by using the intermediate value; and finally, setting an average error function asa fitness function, and improving a quantum particle swarm algorithm to further approach the true value of the phase shift amount, Gaussian mutation operation is added to the quantum particle swarm algorithm to enable the algorithm to accord with the initial distribution law of particles. The method is reasonable in conception and realizes theoretical improvement, according to the method, approximate pre-estimation of the unknown phase shift amount in four-step phase shift can be achieved, the accuracy of the calculation direction is improved, the accuracy and speed of calculating the true value of the unknown phase shift amount can be improved, the sawtooth solution phenomenon near the true value in a traditional iteration method is effectively overcome, and the method has the advantagesof being extremely high in speed, excellent in solving quality and the like.

Description

technical field [0001] The invention relates to a method for accurately extracting unknown phase shifts based on an optimized quantum particle swarm algorithm, which belongs to the fields of phase shift interferometry and phase extraction, and is especially suitable for the field of extracting unknown phase shifts through iterative algorithms. Background technique [0002] Optical three-dimensional measurement technology is a non-contact, high-precision projected structured light or natural light surface microscopic topography measurement technology, which has been widely used in modern industries such as electronics, automobiles, machining, and textiles. Phase-shifting interferometry (Phase-shifting interferometry, PSI) is an active measurement method in optical three-dimensional measurement technology. It has the advantages of optical three-dimensional measurement technology and has been widely used in various applications from phase measurement to microscope systems. Trad...

AI Technical Summary

Problems solved by technology

At present, the existing phase shift extraction algorithms can be divided into two categories: iterative algorithm and non-iterative algorithm. The iterative algorithm can be divided into alternating iterative algorithm and progressive iterative algorithm according to the different iterative principles. Both of the iterative methods require the object light wave phase Distribution or multiple iterations between the error function and the phase shift value to gradually approach the accurate phase shift value and the phase distribution of the object light wave, the experimental accuracy is affected by the number of iteration steps, and the calculation time is long, so it is difficult to achieve application

The non-iterative algorithm can be divided into the phase shift value solution method based on the statistical characteristics of the phase distribution of the diffraction field, the interferogram extreme value method, and the algebraic fitting method according to the different principles of extracting the phase shift value. Among them, the method based on the statistical characteristics of the phase distribution of the diffraction field The basic basis of the phase shift value solution method is to use the characteristics that the amplitude distribution and phase distribution of the Fresnel diffraction field are independent of each other and the phase distribution of the diffraction field varies approximately randomly. This method will calculate the approximate value of the phase shift. In fact, due to Various practical factors, such as the size of the hologram and the limited number of sampling points, have large errors in the approximate value obtained, and it is necessary to further use an iterative method based on the matching of the interferogram to gradually approach the true value, but , The selection of the phase shift iteration step size has a great influence on the calculation speed: if the step size is too small, it is necessary to increase the number of iterations to reach the real value; if the step size is too large, it is easy to miss the real value, and it is necessary to reduce the step size reverse Looking for, there will be a "sawtooth solution phenomenon" near the true value

Images