Internal thread metrology using photogrammetry

我正在进行的研究将是使用照相系统测量内螺纹。图像将被内部线程的相机捕获。作为我研究的一部分，一种新的计算机视觉算法将被创造出来，从这些图像中进行精确的测量。相机系统将需要专门设计用于捕捉小内部螺纹图像的光学元件。测量的内螺纹最小为M6，最大为M28。该项目的主要目标是开发一种新的内螺纹测量计算机视觉算法。该系统应使用数码相机捕捉内螺纹的图像，并应在相机上安装合适的光学器件以实现这一功能。然后将创建一种新的算法，从捕获的图像中对线程进行测量，并且测量必须具有很高的精度。该算法应至少能够测量内螺纹的大径、小径和节径。目前测量内螺纹的方法是使用螺纹量规，这是一种缓慢、不准确和人工密集的方法，用于检查内螺纹是否符合相应的ISO标准。螺纹规只是拧到螺纹上，如果它们不卡住，则认为该螺纹符合标准，因此螺纹只提供合格/不合格响应，不提供任何测量信息。一种新的计算机视觉算法可以快速准确地进行测量。通过简单地将相机插入螺纹中，可以为ISO规范中的每个受控参数提供测量信息。该测量信息对安全关键设备特别重要。该项目由EPSRC通过iCase奖资助，因此EPSRC认为它是相关的。内螺纹测量问题被认为是一个工程问题，因此工程和物理科学委员会（EPSRC）认为它在他们的范围内。

The study I am undertaking shall be to make measurements of internal threads using a camera system. Images will be captured by the camera of the internal threads. A novel computer vision algorithm will then be created as part of my research to make accurate measurements from those images. The camera system will need optics specially designed for capturing images of small internal threads. The smallest internal thread to be measured shall be M6 and the largest shall be M28. The main objective of the project is to develop a novel computer vision algorithm for internal thread metrology. The system shall use a digital camera to capture images of an internal thread and suitable optics should be attached to the camera to enable this. A novel algorithm will then be created to take measurements of the threads from the captured images and the measurements shall be to a high degree of accuracy. The algorithm should be able to measure at least the major, minor and pitch diameter of the internal thread. The current methods for measuring internal threads use thread gauges which are a slow, inaccurate and manually intensive method for checking that internal threads have met their appropriate ISO standards. Thread gauges are simply screwed into a thread and if they do not get stuck then the thread is considered to meet standards, therefore threads only provide a pass/fail response and do not provide any measurement information. A novel computer vision algorithm can make measurements quickly and accurately. Measurement information can be provided for each controlled parameter in the ISO specification by simply inserting a camera into the thread. This measurement information is of particular interest to safety critical devices.This project is funded by the EPSRC through an iCase award and therefore the EPSRC consider it to be relevant. The problem of internal thread measurement is considered to be an engineering problem and therefore the Engineering and Physical Sciences Council (EPSRC) have considered it to be within their scope.