SBIR-STTR Award

The profile of aircraft surfaces is a critical factor in the performance, efficiency and load capacity of aircraft. Curvature, attack angles, leading and trailing edges of wings determine the lift and drag of the plane during take-off, cruising and landing. Changes in aircraft surface profile occur during the life of an aircraft due to service or impact loads. Quantitative measurement of smoothness, contour and profile of aircraft surfaces are needed in order to monitor conditions that affect the performance of planes. We propose a novel non-contact, optical imaging method based on dynamic structured light to obtain an accurate 3-D map of the surface of aircraft parts. The surface elevation at any location can then be automatically and quickly determined from measurements of the light and dark changes at that point, without considering any other points on the surface at resolutions up to 0.01 inch over an 8 ft2 area. This automated non-contact system for measuring aircraft surface profile will characterize the condition of aircraft before and after maintenance operations. The system can be used to locate and quantify dents, dings, loose rivets or screws as well as possible failures of interior components, detected by subtle changes in the surface profile. The DSL 3-D surface measurement technology can considerably benefit both the military and commercial sector. Shrinking defense budgets are calling for improved utilization of existing resources and reducing maintenance and overhaul time, while maintaining or increasing level of performance. The maintenance and repair of aging aircraft is one of the critical issues addressed under the new restructuring of defense programs. The proposed technology will greatly help the defense sector in meeting some of these objectives, by improving the state-of-the-art in the inspection of aircraft airframe structures by characterizing the condition of aircraft wing surfaces before and after maintenance operations.

Keywords:
Noncontact, Dynamic-Structured-Light (DSL), Finges, 3-Dimensional, Aircraft Surfaces, Measurement, Sensor

During the first six months of the Phase I effort, Karta Technologies designed, assembled and tested a Dynamic Structured Light (DSL 3-D) prototype for three-dimensional surface measurements. This instrument has already attained the basic specifications the ALC requires for inspection of surface damage on aircraft such as the C-130. We tested the instrument with actual aircraft parts, including a large wing section and C-130 skin panels provided by the sponsor. We measured a five-foot wide aircraft surface in a total inspection time of 2 minutes between the start of the scan and the display of the reconstructed 3-D surface. At the end of Phase II we will deliver a fully fieldable instrument to Hill AFB so the ALC can incorporate it into its normal workflow.

Keywords:
3d Measurement, Reverse Engineering, Surface Damage, Aircraft Inspection