Monocular In-flight Measurement of Airfoil Deflections

The knowledge of the actual shape of an aeroplane’s wing in midair is crucial to perform realistic flow simulations. Based on these analyses, the shape of a wing can be optimized by constructive measures and by the selective emptying of the fuel tanks installed inside the wings. As a result, the fuel consumption is reduced and fewer emissions occur. Furthermore, monitoring wing deflections allows for conclusions about the mechanical load and thus the service limit of an airfoil. To determine the wing deflection, we present the concept of a deployed measuring system consisting of measuring marks attached to the wing’s surface and a single camera. A basic model for the bending of a wing is explained and utilized, which assumes the preservation of arc lengths on the wing’s upper surface during bending. The measuring system was successfully applied during several long-distance flights with wide-body aircraft. The design of the measurement system, its setup and calibration, as well as obtained results are presented and discussed.