Use of augmented reality in aircraft maintenance operations

This paper illustrates a Human-Machine Interface based on Augmented Reality (AR) conceived to provide to maintenance operators the results of an impact detection methodology. In particular, the implemented tool dynamically interacts with a head portable visualization device allowing the inspector to see the estimated impact position on the structure. The impact detection methodology combines the signals collected by a network of piezosensors bonded on the structure to be monitored. Then a signal processing algorithm is applied to compensate for dispersion the acquired guided waves. The compensated waveforms yield to a robust estimation of guided waves difference in distance of propagation (DDOP), used to feed hyperbolic algorithms for impact location determination. The output of the impact methodology is passed to an AR visualization technology that is meant to support the inspector during the on-field inspection/diagnosis as well as the maintenance operations. The inspector, in fact, can see interactively in real time the impact data directly on the surface of the structure. Here the proposed approach is tested on the engine cowling of a Cessna 150 general aviation airplane. Preliminary results confirm the feasibility of the method and its exploitability in maintenance practice.