US 7,370,829 B2
Method and system for controlling helicopter vibrations
Askari Badre-Alam, Apex, N.C. (US); Douglas Swansor, Cary, N.C. (US); and Jeffrey Cranmer, Holly Springs, N.C. (US)
Assigned to Lord Corporation, Cary, N.C. (US)
Filed on Jun. 10, 2005, as Appl. No. 11/149,514.
Claims priority of provisional application 60/578645, filed on Jun. 10, 2004.
Prior Publication US 2006/0054738 A1, Mar. 16, 2006
Int. Cl. B64C 11/00 (2006.01)
U.S. Cl. 244—17.13  [381/71.1; 180/312] 50 Claims
OG exemplary drawing
 
1. A vibration canceling force generator for actively generating a vibration canceling force, said vibration canceling force generator comprising:
a resonant actuator having a natural resonant frequency, and a resonant actuator electronic control system having a command input for receiving a command signal, said resonant actuator electronic control system providing an electrical drive current to said resonant actuator to drive said resonant actuator about said resonant frequency when commanded by a received command signal, said resonant actuator having a direct feedback electrical output, said direct feedback electrical output directly fed back into said resonant actuator electronic control system wherein said resonant actuator electronic control system adjusts said electrical drive current based on said resonant actuator direct feedback electrical output to generate said vibration canceling force.