System and method for measuring a bulb diameter of an installed one-sided fastener in a structure

A computer-implemented system for measuring a bulb diameter of an installed one-sided fastener in an aircraft structure, the computer-implemented system comprising:

• the aircraft structure having a front side and a back side, and a plurality of holes formed through the aircraft structure;
• the installed one-sided fastener installed through one of the plurality of holes in proximity to an open hole of the plurality of holes, the installed one-sided fastener having a fastener body protruding from the back side of the aircraft structure, and the fastener body having a fastener bulb with the bulb diameter;
• an optical imaging system comprising:
• a probe having a probe tip coupled to a probe rod, the probe tip having a light element and a lens opening;
• a camera sensor;
• and
• a linear axis slide coupled to the probe rod;
• image data, taken and generated with the optical imaging system, the image data comprising at least a first image of the fastener bulb against the back side of the aircraft structure taken from a first position beyond the back side of the aircraft structure, and at least a second image of the fastener bulb against the back side of the aircraft structure taken from a second position positioned a predetermined distance from the first position;
• and
• a post image processing system, to process the image data, and to determine a bulb diameter measurement of the bulb diameter of the installed one-sided fastener, the post image processing system comprising:
• a control system comprising a computer system comprising:
• one or more computers with one or more processor devices, an operating system, and a computer memory;
• and
• one or more computer software programs processed by the one or more processor devices of the one or more computers;
• a trained artificial intelligence model stored in the computer memory and processed with the one or more processor devices, the trained artificial intelligence model trained to identify the installed one-sided fastener installed through the one of the plurality of holes and to define edges of the installed one-sided fastener, and the trained artificial intelligence model comprising an artificial intelligence model trained on a training data set comprising installed one-sided fastener images of previously installed one-sided fasteners installed in one or more aircraft installation structures, to obtain the trained artificial intelligence model, and wherein the trained artificial intelligence model provides an increased bulb diameter measurement accuracy of the bulb diameter measurement, by identifying the installed one-sided fastener and defining and outlining the edges of the installed one-sided fastener;
• and
• one or more of, an edge detection process, an ellipse fitting process, and a stereo vision process, used to determine the bulb diameter measurement of the bulb diameter of the fastener bulb of the installed one-sided fastener.

A computer-implemented method for measuring a bulb diameter of an installed one-sided fastener installed in a structure, the computer-implemented method comprising the steps of:

• positioning an optical imaging system at a front side of the structure directed at an open hole in the structure, the open hole in proximity to the installed one-sided fastener installed in the structure, and the optical imaging system comprising:
• a probe having a probe tip coupled to a probe rod, the probe tip having a light element and a lens opening;
• a camera sensor;
• and
• a linear axis slide coupled to the probe rod;
• inserting the probe tip through the open hole to a first position beyond a back side of the structure, so that the lens opening is directed at the installed one-sided fastener, the installed one-sided fastener having a fastener body protruding from the back side of the structure, and the fastener body having a fastener bulb with the bulb diameter;
• taking and generating, with the optical imaging system, from the first position, a first image of at least the fastener bulb against the back side of the structure;
• moving the probe tip a predetermined distance from the first position to a second position beyond the back side of the structure, so that the lens opening is directed at the installed one-sided fastener;
• taking and generating, with the optical imaging system, from the second position, a second image of at least the fastener bulb against the back side of the structure;
• and
• processing the first image and the second image with a post image processing system, the post image processing system comprising:
• a control system comprising a computer system comprising:
• one or more computers with one or more processor devices, an operating system, and a computer memory;
• and
• one or more computer software programs processed by the one or more processor devices of the one or more computers;
• a trained artificial intelligence model stored in the computer memory and processed with the one or more processor devices, the trained artificial intelligence model trained to identify the installed one-sided fastener installed through the one of the plurality of holes and to define edges of the installed one-sided fastener, and the trained artificial intelligence model comprising an artificial intelligence model trained on a training data set comprising installed one-sided fastener images of previously installed one-sided fasteners installed in one or more installation structures, to obtain the trained artificial intelligence model;
• and
• one or more of, an edge detection process, an ellipse fitting process, and a stereo vision process,
• wherein the step of processing comprises sub-steps of:
• using the trained artificial intelligence model to identify the installed one-sided fastener and to define the edges of the installed one-sided fastener;
• and
• using one or more of, the edge detection process, the ellipse fitting process, and the stereo vision process, to determine a bulb diameter measurement of the bulb diameter of the fastener bulb of the installed one-sided fastener, and wherein the trained artificial intelligence model provides an increased bulb diameter measurement accuracy of the bulb diameter measurement, by identifying the installed one-sided fastener and defining and outlining the edges of the installed one-sided fastener.