A Novel Contactless Sensor for Helicopter Blade Motion In-flight Measurements

摘要

A fundamental output of the CleanSky project MANOEUVRES (Manoeuvring Noise Evaluation Using Validated Rotor State Estimation Systems) is represented by the design, development and testing of an innovative measurement system for the real-time acquisition of the motion of a helicopter main rotor blade. In fact, the MANOEUVRES project was carried out as a 30-month activity, ended in March, 2016, with the aim of delivering new solutions for rotorcraft in-flight noise monitoring [1, 2]. To this end, a methodology to estimate the acoustic impact in real time has been developed, which integrates several components in order to finally present a synthetic noise index to the pilot through a dedicated cockpit instrument, the Pilot Acoustic Indicator [3, 4]. Among these components, a major role is played by the availability of real-time, accurate measurements of the flapping of the main rotor blades. This motion can be related to the rotor tip-path-plane (TPP) angle of attack, which in turn is one of the main parameters governing rotorcraft noise emission, along with helicopter advance ratio and thrust coefficient [5]. In addition to on-board noise estimation, in support to low acoustic impact terminal procedures, the presence of such a rotor state measurement system allows to consider Rotor State Feedback (RSF) strategies to design innovative attitude control laws that can significantly improve pilot/vehicle capabilities while reducing human workload [6].