Flight-Rated Fault-Tolerant Rotor State Sensor

A novel system for the measurement of rotor states is proposed for development, to be used as part of a control system in the support of advanced helicopter (and tiltrotor) handling qualities and flight dynamics improvements. The design builds on extensive prior rotor instrumentation work that has supported numerous wind tunnel testing research programs, but adds robustness and fault-tolerant features permitting its use as part of a man-rated flight control system. Key to the rotor state measurement approach is the use of on-blade acceleration measurements that provide enhanced tracking performance in the rotor state estimator, and the capability to incorporate a simple algorithm in the processing of raw sensor signals. Robustness is provided through the implementation of the estimator in individual microprocessors co-located with the instrumentation on each blade, thus permitting the use of voting schemes for handling degraded sensor signals or other system faults. The proposed workplan addresses the technical challenges associated with converting this concept to a functional and reliable piece of man-rated flight hardware.