Internal thread metrology using photogrammetry

我正在进行的研究将使用摄像系统测量内螺纹。图像将被内部线程的摄像头捕获。然后，作为我研究的一部分，将创建一种新的计算机视觉算法，以根据这些图像进行准确的测量。相机系统将需要专门设计的光学元件来捕捉小内螺纹的图像。被测量的最小内螺纹为M6，最大内螺纹为M28。该项目的主要目标是开发一种新的内螺纹计量的计算机视觉算法。系统应使用数码相机来捕捉内螺纹的图像，并应在相机上安装适当的光学元件以实现这一点。然后将创建一种新的算法来从捕获的图像中测量线条，并且测量应达到高精度。该算法至少应该能够测量内螺纹的大、小和中径。目前测量内螺纹的方法使用螺纹量规，这是一种缓慢、不准确且需要大量人工检查的方法，用于检查内螺纹是否符合其适当的ISO标准。螺纹规只是简单地拧入螺纹中，如果它们没有卡住，则认为该螺纹符合标准，因此螺纹只提供通过/失败响应，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。只需将摄像机插入线中，即可为ISO规范中的每个受控参数提供测量信息。这些测量信息对安全关键设备特别重要。该项目由EPSRC通过iCASE奖项提供资金，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理事会(EPSRC)认为它属于他们的范围。

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.