Optical Feather and Foil for Shape and Dynamic Load Sensing of Critical Flight Surfaces

Future flight vehicles may comprise complex flight surfaces requiring coordinated in-situ sensing and actuation. Inspired by the complexity of the flight surfaces on the wings and tail of a bird, it is argued that increasing the number of interdependent flight surfaces from just a few, as is normal in an airplane, to many, as in the feathers of a bird, can significantly enlarge the flight envelope. To enable elements of an eco-inspired Dynamic Servo-Elastic (DSE) flight control system, IFOS proposes a multiple functionality-sensing element analogous to a feather, consisting of a very thin (gauge 18 or 20) tube with strain sensors and algorithms for deducing the shape of the "feather" by measuring strain at multiple points. It is envisaged that the "feather" will act as a unit of sensing and/or actuation for establishing shape, position, static and dynamic loads on flight surfaces and in critical parts. IFOS proposes to develop advanced sensing hardware and software control algorithms to demonstrate the proposed DSE flight control concept. The hardware development involves an array of optical fiber based sensorized needle tubes for attachment to key parts for dynamic flight surface measurement.