MIMO Hybrid Control of Structural Responses for Helicopter

A MIMO hybrid model of structural response control, which combines adaptive feedforward control and feedback control, was developed and then applied in a helicopter model to eliminate the dual-frequency harmonious vibration at cabin seats. In implementation, an AOEF (Acceleration Output Extended Feedback) controller for the MIMO case was designed to add enough damping to the control path so that the convergence rate of the FXLMS algorithm could be obviously improved. The corresponding FXLMS algorithm for the control path of closed loop was developed also. The numerical results on the finite element model of a helicopter indicated that with hybrid control, responses at four rows of seats could be controlled with two actuators and the adaptive controllers got a quicker convergence rate.