基于仿人眼层状柔性可调透镜的机器视觉变焦成像技术研究

Zoom imaging system plays an important role in machine vision system, which is the basis of visual information acquisition and processing. The existing machine vision zoom imaging system generally has complex structure, small adjustment capacity and large volume, which impedes the integrated design of the system. This project applies the tunable lens technology into the design of machine vision zoom system, and utilizes the biomimetic flexible tunable lens with multilayered structure as the key component, in order to explore the design theory and implementation method of machine vision zoom system based on flexible tunable lens. The specific research contents include: imitating the solid-liquid mixed multilayered structure and regulation method of the human eye, and studying the design and fabrication method of biomimetic flexible tunable lens based on the application characteristics of machine vision system; using the biomimetic tunable lens as the main zoom unit, and synthesizing the aberration properties and multi-structure parameters to construct the design method of the machine vision zoom system; combined with the specific application of industrial visual inspection technology, constructing the zoom experimental system, designing the fast focusing method based on depth from focus, and evaluating the reliability and stability of the system. Through accomplishing the above research, this project aims at developing a prototype of the biomimetic flexible tunable lens, constructing a design method for the machine vision zoom system, and promoting the industrial application of the flexible tunable lens technology.

变焦成像在机器视觉系统中发挥重要作用，是视觉信息采集与处理的基础。现有的机器视觉变焦成像系统存在着机构复杂、调节能力小、体积大问题，难以满足集成化设计要求。本项目将可调透镜技术应用于机器视觉变焦成像系统中，以仿人眼层状柔性可调透镜为关键器件，探索基于柔性可调透镜的机器视觉变焦成像系统设计理论与实现方法。具体内容包括：模拟人眼固液混合层状结构特点与调节机理，根据机器视觉系统应用特点，研究新型仿人眼层状柔性可调透镜设计与制备方法；利用柔性可调透镜作为主要变焦单元，综合透镜的像差特点和多结构参数，建立基于可调透镜的机器视觉变焦系统设计方法；结合工业视觉检测具体应用，搭建机器视觉变焦成像实验系统，设计基于对焦深度法的可调透镜快速调焦方法，验证系统的稳定性和可靠性。通过以上研究，最终研制出新型仿人眼层状柔性可调透镜原理样机，形成一种新的机器视觉变焦成像系统设计方法，促进柔性可调透镜技术的工业化应用。

项目通过模拟与分析人眼的生理特点与光学模型，根据弹性聚合物材料的特点，研制仿人眼柔性多层可调透镜原理样机。对聚合物材料的本构关系进行分析，提出可调透镜的制作方法与工艺流程。搭建可调透镜实验平台，对可调透镜的形变特点、成像效果、调焦过程进行测试，完成可调透镜光学特性的仿真实验与分析。结合工业视觉检测具体应用，针对管道及金属工件表面机器视觉检测问题，提出自适应图像增强算法与缺陷边缘提取方法，建立基于光度立体法的金属工件表面缺陷视觉检测方法，实现典型管道及金属表面缺陷的准确快速检测。通过项目研究，研制出仿人眼层状柔性可调透镜，建立基于机器视觉的零部件表面缺陷检测方法，发表学术论文9篇，获得发明专利4项，开展了一系列的应用和实验研究。项目的研究对光学成像、机器视觉与工业自动化检测技术发展具有重要的理论意义和应用价值。