Patent ID: 8382028

Claim:
A rotary wing aircraft, having an aircraft body interior cabin space supported in flight through an exterior air space by a rotary wing system rotating with an operational rotating frequency, said rotary wing aircraft having a persistent operational rotating frequency vibration, said rotary wing aircraft including: an operational rotating frequency reference sensor, said operational rotating frequency reference sensor outputting a rotating frequency signal indicative of the rotary wing system operational rotating frequency, a first imbalance rotor having a first mass concentration, said first imbalance rotor driven to rotate with a first controllable phase (φ_ 1 _ 1 ), a second imbalance rotor having a second mass concentration, said second imbalance rotor driven to rotate with a second controllable phase (φ_ 1 _ 2 ), a third imbalance rotor having a third mass concentration, said third imbalance rotor driven to rotate with a third controllable phase (φ_ 1 _ 3 ), a fourth imbalance rotor having a fourth mass concentration, said fourth imbalance rotor driven to rotate with a fourth controllable phase (φ_ 1 _ 4 ), a plurality of vibration sensors for monitoring said vibration and outputting vibration signals, a system controller, said system controller receiving said outputted rotating frequency signal, said system controller also receiving said vibration sensor signals wherein said system controller independently and automatically controls each of said first imbalance rotor first controllable phase (φ_ 1 _ 1 ), said second imbalance rotor second controllable phase (φ_ 1 _ 2 ), said third imbalance rotor third controllable phase (φ_ 1 _ 3 ), and said fourth imbalance rotor fourth controllable phase (φ_ 1 _ 4 ), relative to said rotating frequency reference signal with said first phase (φ_ 1 _ 1 ), said second phase (φ_ 1 _ 2 ), said third phase (φ_ 1 _ 3 ), and said fourth phase(φ_ 1 _ 4 ) not in a fixed phase relationship to produce a first biaxial force and a moment which reduces the vibration signals outputted from said vibration sensors.