Contactless Rotor Flapping Sensor Design, Implementation and Testing

The present contribution aims at providing a comprehensive illustration of a structured approach to the design, implementation and testing of a new rotor state measurement system for rotorcraft applications. This effort has been carried out in the framework of a Clean Sky collaborative project in which the novel sensor system plays a fundamental role by enabling the real-time estimation of non-measurable quantities that govern the rotorcraft running acoustic emission, in view of external noise alleviation. Furthermore, the availability of the new sensor system capable to accurately capture rotor blade motion allows the derivation of enhanced attitude control laws based on rotor state feedback. We detail the complete process that led to the full-scale development of a stereoscopic vision-based measurement system mounted on the rotor head, which has been fully integrated on board a prototype helicopter for ground and flight testing.