Internal thread metrology using photogrammetry

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.