Dynamic and non-contact optical diameter measurement system for manufacturing processes

In this thesis, we designed and implemented four distinct optical systems capable of measuring the diameter of cylindrical objects (rods and screws) in motion during production processes without contact and with high precision. The developed systems were classified as 360° surface imaging, lensless shadow imaging method, telecentric imaging, and telecentric shadow imaging system. To assess the precision, repeatability, and real-time measurement capabilities of these systems, we performed experimental measurements on reference rods and industrial screws with different diameters. The outcomes were contrasted with established systems in the literature and reference data obtained using calipers. During this process, we developed image processing software for image analysis, precise edge detection, and automatic diameter calculations, along with a measurement verification framework that encompasses all analytical steps. Notably, the telecentric shadow imaging system achieved high accuracy, with a deviation of ±0.02 mm in images captured from different angles. The developed software also enabled the automatic calculation of the inner and outer diameters of medical screws, demonstrating the system's reliability in analyzing gear structures. The results indicated that the developed systems effectively met the tolerance limits required in fields such as automotive manufacturing, medical device production, and general industrial quality control. However, it was determined that for applications necessitating higher precision, such as those in the aerospace and defense industries, enhancements to the optical components of the systems are essential, along with the implementation of more advanced calibration techniques.