Design And Application Of The Multi-Focusing Compound Eye Imaging System

About a quarter of the world’s animals use compound eyes.The advent of compound eye vision has changed the ability of animals to explore the world.The continuous evolution of compound eyes allows animals to have a richer understanding of their environment.The unique structure of compound eye has attracted the attention of many researchers.Human monocular can only image a single point,while compound eye can image multiple points simultaneously,and has the advantages of miniaturization,large field of view,high integration and high time resolution.Therefore,compound eye has a broad application prospect,which makes more and more research on compound eye imaging system.With the continuous improvement of MEMS(Micro Electro Mechanical Systems)technology,people’s research on bionic compound eyes and its application has made compound eyes develop rapidly from planar microlens array(MLA)to curved compound eyes,and gradually transition from principle bionics to structure and function bionics.The field Angle,imaging quality and resolution of the bionic compound eye are continuously improved:The small field Angle of planar microlens array limits its application.Curved multi-focal length compound eyes can obtain multi-channel images,so that the focal length is unified in the same plane,and large field of view and high quality images can be obtained.On this basis,this paper proposes relevant innovative preparation technology to prepare a complete meniscus compound eye imaging system and develop adaptive application program.The innovative research content and work of this paper revolve around the following parts:(1)In view of the problem that compound eye lens and plane image sensor cannot be directly matched,firstly,a three-dimensional model of compound eye lens is established by studying the imaging mechanism of compound eye,and the initial diameter and vector height of each sub-eye are calculated by geometric optics principle,so as to correct the defocus phenomenon of compound eye lens at different positions on the curved surface.Then the initial parameters were substituted into the optical simulation software for analysis and optimization to improve the aberration of compound eye lens imaging.When optimizing the vector height of compound eye through mirror eye,the relationship between the linear shape of the aperture of different diameters in the negative pressure molding of PDMS film should be taken into account.(2)Aiming at the problems of long preparation period and low accuracy of compound eye lens,a negative pressure molding technology based on MEMS process was proposed to quickly and accurately prepare high-resolution multi-focal meniscus compound eye.Using the combination of photolithography,etching,soft photolithography,magnetron sputtering,ultraviolet curing,negative pressure molding and other technologies,each stage of the prepared compound eye lens can be accurately controlled,and the resolution can be improved.With a meniscus base,volume and mass are reduced,and greater field Angle and higher utilization of light energy are provided.The use of meniscus structure reduces the reflection of light in the interior of the base,and when the incidence Angle is large,the use of convex structure will lead to total reflection.When the incidence Angle is 50 degrees,the curvature of meniscus structure is less than that of convex structure,and the energy is higher.This process has the characteristics of simple preparation and short cycle,and the efficiency of preparing curved compound eyes is significantly improved by transferring the planar microlens pattern to a curved surface.(3)To meet the needs of large-field stitching and motion tracking and recognition of compound eye cameras,corresponding programs are developed based on the characteristics and advantages of compound eye imaging system.One is the large-field stitching algorithm based on HARRIS corner detection,which has a good stitching effect on the large-field stitching of compound eye cameras and can realize wide-angle panoramic images.The other is a moving object tracking program based on Gaussian mixture model.By capturing the movement of moving objects in space,rapid target recognition is realized,giving full play to the characteristics of large field of view and high sensitivity of compound eye.