Under the FAA Aging Aircraft Research program (grant # G03 19014) we are developing robots to deploy conventional and later new-concept NDI sensors for commercial aircraft skin inspection. Our prototype robot the Automated NonDestructive Inspector (ANDI) holds to the aircraft skin with vacuum assisted suction cups scans an eddy current sensor and translates across the aircraft skin via linear actuators. Color CCD video cameras will be used to align the robot with a series of rivets we wish to inspect in a linear scan using NDI inspection sensors. In this paper we provide a background scenario and describe two different solutions to the alignment problem: a model-based system built around edge detection and a trainable neural network system.
Ian L. Davis,
"Automated nondestructive inspector of aging aircraft", Proc. SPIE 2101, Measurement Technology and Intelligent Instruments, (22 September 1993); doi: 10.1117/12.156432; https://doi.org/10.1117/12.156432