【作者】 杨治亮；

【导师】 陈立国；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2008， 硕士

【摘要】 显微视觉在微操作和微装配中起着极其重要的作用,显微视觉可以通过非接触的视觉反馈提供微操作目标的显微几何、空间关系以及更高级别的信息。但是,考虑到显微光学的独特属性,显微视觉与宏观视觉有很大的区别,其中显微镜景深有限是一个在微操作和微装配中应用时必须考虑的最为突出的特点。在微操作过程中存在非平面目标,同时需要聚焦于不同的高度。如何聚焦于不同的高度以及得到目标的三维信息已经成为将显微视觉应用于微操作和微装配的一个主要障碍。本文首先分析了深度信息恢复的研究现状,其中两种技术-基于聚焦和基于离焦的方法是适用于微操作和微装配的。然后通过分析显微镜的成像原理和模糊图像的形成过程发现图像的模糊程度可以用来恢复目标的三维信息,这种方法只需要单目普通光学显微镜就可以完成。在微操作过程中需要聚焦于不同高度的平面,因此自动调焦是必不可少的,本文提出了两种适用于微操作的基于离焦的快速自动调焦方法。为了达到自动调焦效率与精度兼顾的目的提出了另一种将离焦与聚焦结合的方法。实验证明这种方法在效率与精度之间做了很好的平衡。在典型的三维微装配过程中,动态记录目标的位置信息和空间关系非常重要。微操作目标在三维空间的位置应该被实时的跟踪,本文提出了一种基于单目视觉的新颖的三维跟踪技术。一种被广泛应用于宏观视觉的二维跟踪方法camshift被应用于显微视觉对模糊目标进行二维跟踪,同时基于离焦(DFD)方法被用来得到微操作目标的相对高度信息,最后将camshift与DFD相结合成功的恢复了微操作目的运动轨迹。最后,通过跟踪调焦和模糊操作两个综合实验的研究进一步证明了各种技术综合应用于微操作和微装配领域的重要意义。更多还原

【Abstract】 Microscopic computer vision is of fundamental importance to micromanipulation and microassembly in providing noncontact feedback of microscale geometry, spatial relations and high-level task understanding .However, because of the unique properties of microscope optics, microscopic computer vision differs significantly from macroscale computer vision. The small depth-of-field of microscope optics is a fundamental constraint that must be considered in developing microscopic computer vision techniques for micromanipulation and microassembly. In a typical microassembly situation there are non-planar objects and several different focal planes. How to focus on different planes and get the 3D information has become a major roadblock to the development of practical visual applications to micromanipulation and microassembly.In this paper, firstly we analysis the state of depth information recovery and two technichs Depth-from-Focus and Depth-from-Defocus are found to be feasible for micromanipulation and microassembly,then the principle of microscope and the forming process of blurred images are analysied.we found that the level of defocus of images can be used for 3D information recovery for micromanipulation and microassembly using a single optical microscope.In a typical microassembly situation there are several different focal planes. Accordingly, autofocusing is an essential operation to focus on different depth. Two new effective fast autofocusing methods based on image defocus is presented for microscopy images in micromanipulation. A unified approach to DFF and DFD is constructed and experimentally demonstrated to be efficient and effective for common optical zoom microscope, it made a good trade-off between accuracy and efficiency.Dynamic measurement of poses of the objects of interest and their spatial relations is important in a typical 3D microassembly situation; the micro object should be tracked in the 3D space in real time. In this paper, a novel imaging technique is proposed.This technique tracks 3D coordinates of micro-object for micromanipulation and microassembly using a single optical microscope. A widely used macroscale 2D tracking method called camshaft is used for microscopy images to track defocusing miro-object. And a depth from defocus based method is used to obtain the depth information in z direction. The integration of these two techniques is implemented successfully for obtaining 3D trajectories of micro-object.At last, conpretentive experiments are designed to validate the feasible of our theory for manipulation and microassembly.更多还原