Automated Visual Guidance and Direct Metrology for Precision Manufacturing

本课题的研究目的是确定一个三维物体的位姿是否可以完全由白光干涉法在一张图像上的横向条纹分布来定义，以及白光干涉法是否可以同时测量多个微物体的多轴运动。该方法首先建立得到的侧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姿态的观测器和相关的可观测性。将进行实验来验证推导的可观测性，并检查与结构振动和图像量化相关的可实现运动分辨率。其次，优化横向条纹图分析的实时计算，并通过实验验证该观测站的时间分辨率。具体而言，将建立与图像大小，物体几何形状和物体数量相关的可实现的时间分辨率。在对运动分辨率和时间分辨率进行验证后，将该方法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。如果成功，这项研究将导致新的传感器技术，能够同时测量多个微物体的六自由度运动，包括工程设备，生物结构，测量探针或操纵器，具有纳米分辨率。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、动态跟踪和控制操作。当与工具的创新设计和实现相结合时，所提出的测量技术可以应用于各种精密制造过程。它可以实现直接测量，用于测量应用中最重要的运动，直接视觉伺服控制，消除校准误差，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，并对精密制造的先进仪器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拓宽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、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.