Full Band Anticipatory Control Algorithms to Suppress Aggressive Maneuver Vibrations

Recent high usage of helicopters in Iraq and Afghan theatres underscores a need for improvements in rotorcraft safety and reliability. Rotor induced vibrations contribute significantly to airframe fatigue, electronic component failure, and pilot workload. In current generation rotorcraft, vibration attenuation is achieved through either airframe mounted tuned-absorbers or active vibration control (AVC) systems. Typical AVC systems use a number of narrow band force generators to reduce accelerations measured at multiple locations in aircraft fuselage. Although current AVC systems are effective at reducing vibration in steady flight, advanced control algorithms are needed to achieve similar results for transient maneuvers. To address deficiencies of current AVC algorithms, Materials Technologies Corp. has formed an exceptionally talented team with experience in rotorcraft modeling, modern control algorithm development, and AVC system development. During the Phase-I effort this team developed state-of-the-art time domain control technologies that addressed known deficiencies in production control algorithms and demonstrated the performance using a high fidelity fuselage model developed in coordination with Sikorsky Aircraft. Lessons learned in Phase I will be leveraged in Phase II to further refine and optimize these control algorithms. Operating envelope will be expanded, and real-time capabilities will be evaluated in a hardware-in-the-loop demonstration on existing AVC test rig at Sikorsky to perform similar evaluations for production AVC controller.