Research On Sub-aperture Stitching Technology Based On Swarm Intelligence Optimization Algorithm

With the development of science and technology,large-aperture optical components are increasingly used in high-end systems(such as aerospace camera equipment,astronomical telescopes,semiconductor lithography machines,laser-induced nuclear fusion systems,etc.).These components are typically machined using computer numerically controlled polishing techniques that perform controlled compensation processing based on the original surface shape of the component under test.Among them,the surface data is generally measured by a high-precision laser interferometer.For large-aperture optical elements,their detection often requires the interferometer to be equipped with a standard mirror that is equal to or larger than its caliber.However,large-diameter standard mirrors need a long manufacturing cycle and high cost;and the size of large-aperture optical elements in each system gradually increases.Therefore,the use of larger-sized standard mirrors for interferometry does not meet the requirements for efficient and economical manufacturing.Sub-aperture stitching technology uses a small-caliber laser interferometer to perform full aperture scanning and stitching to obtain large-diameter surface data.However,the existing splicing algorithms are low efficiency,complicated models,and they are sensitive to mechanical positioning errors.This paper presents a sub-aperture stitching technology based on swarm intelligence optimization algorithm.The utility model has the advantages of realizing the splicing measurement of medium and large calibers,reducing the detection cost,improving the surface precision,and reducing the sensitivity of the splicing algorithm to mechanical positioning errors.The research work of this article is mainly divided into the following parts:1.The sub-aperture stitching interferometry principle is discussed,and a math-ematical model for the sub-aperture stitching is established.The commonly used sub-aperture classification methods and arrangements are studied.Based on different methods of partitioning and arrangement,the relationship between the area of the overlapping area and the number of sub-apertures required is deduced.The error of sub-aperture measurement was deduced by mathematical statistics.The effects of different splicing modes and different overlapping coefficients on the sub-aperture splicing precision were studied by numerical simulation.2.The commonly used swarm intelligence algorithm is studied,and the Cuckoo Search algorithm with good algorithm is selected.The process of applying the swarm energy algorithm to sub-aperture stitching is studied,and the fitness function is established.Based on the CS algorithm,an improved Dynamic Cuckoo Search algorithm is proposed based on the population similarity.The types of positioning errors are analyzed for different mobile platforms,and different fitness functions are constructed for different positioning errors.The effectiveness of the algorithm is verified by simulation experiments.3.In order to evaluate the accuracy of the stitching,the evaluation indicators for the surface shape error evaluation of the commonly used surface shape error evaluation digital index,power spectrum density curve in the frequency domain,and the stitching accuracy index of the optimal match are proposed.A simple sub-aperture stitching mobile platform was built.The effectiveness of the algorithm is verified by comparing the accuracy of full-aperture surface splicing with sub-aperture stitching and measuring the full aperture.4.Through simulation experiments,the influence of the commonly used overlap region fusion method on the accuracy of stitching is pointed out.For its shortcomings,the wavelet transform fusion sub-aperture overlapping data is applied,and a complete set of sub-aperture stitching measurement software is developed.