3D Machine Vision Enabled Shrinkage Pin Detection of Aviation Connectors in the Aircraft EWIS

Aviation connectors are responsible for information and energy transmission in the aircraft electrical wiring interconnection system (EWIS). Even a tiny shrinkage of any connector pin may lead to a critical impact on the reliability and stability of the EWIS. However, the current detection method of connector pin shrinkage mainly relies on manual visual inspection, which is prone to missed and false detection. Additionally, traditional 2D machine vision methods face challenges in dealing with fine pins and deep calibers of connectors. To address this issue, this paper designs a defect detection device and proposes a 3D-enabled shrinkage pin detection (3D-SPD) algorithm. For the device, a 4-degree-of-freedom (4-DOF) support mechanism is designed to collect the connector point cloud based on the imaging principle of a 3D structured light camera. Then, a preprocessed method is presented to extract defective regions from the raw point cloud. Finally, 3D-SPD algorithm can automatically select the reference plane and detect the pin position, enabling online detection of connector shrinkage pins. Experiment results show that 3D-SPD algorithm is effective in detecting shrinkage pin defects on various types of aviation connectors, with an accuracy rate of 98.62% and a shrinkage pin detection rate of 100%.