Automated Visual Guidance and Direct Metrology for Precision Manufacturing

该研究项目的目的是确定一个三维物体的姿态是否可以完全由白光干涉测量的横向条纹分布在一幅图像中确定，以及是否可以应用白光干涉测量来同时测量多个微观物体的多轴运动。该方法首先建立目标物体横向条纹分布与目标物体六自由度运动之间的数学关系，在此基础上推导出目标物体姿态的观测器及其相关的可观测性。将进行实验以验证导出的可观测性，并检查与结构振动和图像量化相关的可实现的运动分辨率。其次，对横向条纹图样分析的实时计算进行优化，并对所提出的观测器的时间分辨率进行实验验证。具体地说，将建立与图像大小、对象的几何形状和对象数量相关的可实现的时间分辨率。在验证了运动分辨率和时间分辨率后，该方法将应用于白光干涉仪系统视场内多个微物体的六自由度运动测量，如果研究成功，将带来能够同时测量多个微物体的六自由度运动的新型传感器技术，包括工程装置、生物结构、测量探头或机械手，具有纳米级的分辨率。它还将实现自动视觉引导，以实现多尺度微型设备的自动定位、对准、动态跟踪和受控操作。当与工装的创新设计和实施相结合时，所提出的测量技术可应用于各种精密制造过程。它可以实现直接测量，放置在对应用最重要的运动进行测量，并直接进行视觉伺服控制，消除了标定误差、非线性、结构热漂移和传感器漂移的影响。它将在广泛的精密工程问题中具有潜在的应用，并对精密制造中先进仪器的控制和现代制造过程的自动化产生重大影响。此外，该项目的跨学科性质将扩大对研究生和本科生的教育和培训。预计该项目的成果将丰富更广泛的课程开发工作，特别是在传感器设计、光学计量学、视觉伺服控制和微/纳米技术领域。

The objective of this research project is to determine if the pose of a three-dimensional object can be completely defined by the lateral-fringe distribution of white light interferometry in just one image, and if white light interferometry can be applied to simultaneously measure multi-axis motions of multiple micro objects. The approach is to firstly establish the mathematical relationship between the resulting lateral-fringe distribution and the six-degree-of-freedom motion of the targeted object, based on which an observer and the associated observability of the object's pose will be derived. Experiments will be conducted to verify the derived observability and to examine the achievable motion resolution in relation to structural vibration and image quantization. Secondly, real-time computation for lateral-fringe pattern analysis will be optimized and the associated temporal resolution of the proposed observer will be experimentally verified. Specifically, the achievable temporal resolution in relation to image size, object's geometry, and number of objects will be established. After motion resolution and temporal resolution are verified, this approach will be applied to measure six-degree-of-freedom motions of multiple micro objects within the field of view of a white light interferometer system.If successful, this research will lead to novel sensor technology that is capable of simultaneously measuring six-degree-of-freedom motions of multiple micro objects, including engineered devices, biological structures, measurement probes or manipulators, with nanometer resolution. It will also enable automated visual guidance for achieving automatic positioning, alignment, dynamic tracking, and controlled manipulation of multi-scale micro devices. When integrated with innovative design and implementation of tooling, the proposed measurement technique can be applied to various precision manufacturing processes. It can achieve direct metrology, placed to measure the motion which matters most to the application, and direct visual servo control, eliminating the effects of calibration error, nonlinearity, thermal drift of structure, and sensor drift. It will have potential applications in a wide spectrum of precision engineering problems, and a major impact on control of advanced instrumentation and automation of modern fabrication processes for precision manufacturing. Furthermore, the interdisciplinary nature of the project will broaden the education and training of graduate and undergraduate students. It is expected that the results of the project will enrich broader curriculum development efforts, particularly in the areas of sensor design, optical metrology, visual servo control, and micro/nano technology.