Active noise control system for a helicopter gearbox mount

Abstract

An active noise control system for a helicopter for minimizing undesirable acoustic noise in a cabin defined by a cabin structure, wherein the undesirable acoustic noise is generated by high frequency structural vibrations emanating from a gearbox, and wherein the gearbox has a plurality of attachment feet structurally coupling the gearbox to the cabin structure at a plurality of structural interfaces. The active noise control system comprises a sensor subsystem disposed in combination with the cabin for sensing the undesirable acoustic noise in the cabin, an actuator subsystem disposed in combination with at least one of the plurality of attachment feet, and a controller functionally interconnecting the sensor subsystem to the actuator subsystem, the controller being operative to receive input from the sensor subsystem and to transmit command signals to the actuator subsystem in response thereto for generating at least one high frequency counter-vibration that is interactive with the high frequency vibrations to minimize the undesirable acoustic noise in the cabin. The active noise control system further includes at least one flange connected to the attachment feet proximal to the corresponding structural interface, and wherein the actuator subsystem further includes at least one structural actuator disposed in combination with the flange.