System for control of active system for vibration and noise reduction

An active vibration control system for reducing vibration generated by a vibrating plant including a vibrating component, a structure and a hydraulic mount for mounting the vibrating component to the structure, the vibration transmitted from the vibrating component through the hydraulic mount to the structure, the control system comprising:

• a. at least one hydraulic actuator for producing controlled vibrations within the mount;
• b. at least one position sensor for sensing the current position of the hydraulic actuator and producing a signal representative thereof;
• c. at least one vibration sensor for sensing vibrations being transmitted from the vibrating component through the hydraulic mount to the structure and producing a signal representative thereof;
• d. at least one vibrating plant sensor for sensing at least one of the rotational frequencies at which said vibrating plant operates and producing a signal representative thereof;
• e. a fixed, low bandwidth, near-DC, PID-based broadband control compensation feedback position controller which utilizes the position sensor signal to produce position control signals to minimize the offset between the sensed hydraulic actuator position and a predetermined hydraulic actuator position;
• f. an adaptive Filtered-X LMS based narrow-band vibration controller which utilizes the vibration sensor signal to produce vibration control signals at multiple frequencies of the sensed plant characteristic frequencies;
• and
• g. means for combining position control signals with the vibration control signals and generating an output signal, the hydraulic actuator being responsive to the output signal of the combining and output signal generating means for producing controlled vibrations in the mount for reducing vibrations transmitted through the mount from the vibrating component to the structure.

An active vibration control system for reducing vibration in a rotary wing aircraft, the rotary wing aircraft including an airframe and a main rotor system having a rotor, an engine and a transmission gearbox mounted to the airframe for turning the engine force into the rotational force of a rotorshaft, the gearbox attached to the airframe with at least one hydraulic mount between the gearbox and the airframe, wherein the operation of the main rotor system generates vibration that is transferable to the airframe causing vibration on board the aircraft, , the control system comprising:

• a. at least one hydraulic actuator for producing controlled vibrations within the mount;
• b. at least one position sensor for sensing the current position of the hydraulic actuator and producing a signal representative thereof;
• c. at least one vibration sensor for sensing vibrations being transmitted from the main rotor system through the mount to the airframe and producing a signal representative thereof;
• d. at least one rotational sensor for sensing the rotational frequency of the rotorshaft and producing a signal representative thereof;
• e. a fixed, low bandwidth, near-DC, broadband control compensation feedback position controller which utilizes the position sensor signal to produce quasi-static position control signals to minimize the offset between the sensed hydraulic actuator position and a predetermined hydraulic actuator position;
• f. an adaptive Filtered-X LMS based narrow-band vibration controller which utilizes the vibration sensor signal to produce vibration control signals ;
• and
• g. means for combining the position control signals with the vibration control signals and generating an output signal, the hydraulic actuator being responsive to the output signal of the combining and output signal generating means for producing controlled vibrations in the mount for reducing vibrations transmitted through the mount from the engine and rotor system to the airframe.

A method of controlling vibration suppression apparatus means in a mechanical system, the method comprising the steps of:

• sensing a position state of at least one vibrating component in the mechanical system to produce a position sensor signal;
• sensing vibrations of the at least one vibrating component in the mechanical system to produce a vibration sensor signal;
• applying a position control function to the position sensor signal to produce a position control function output signal;
• applying a vibration control function to the vibration sensor signal to produce a vibration control function output signal;
• and
• combining the position control function output signal with the vibration control function output signal to produce a control signal that operates the vibration suppression apparatus.