Active vibration control system

• US 7,017,857 B2
• Filed: 09/16/2002
• Issued: 03/28/2006
• Est. Priority Date: 09/16/2002
• Status: Expired due to Fees

• Current Assignee: Foster-Miller Incorporated (Thermo Fisher Scientific Incorporated)
• Original Assignee: Foster-Miller Incorporated (Thermo Fisher Scientific Incorporated)
• Inventors: Hill, Wayne, Tsimring, Lev S.
• Primary Examiner(s): Dinh, Tien
• Application Number:
  US10/244,583
• Publication Number:
  US 20040050999A1
• Time in Patent Office: 1,289 Days
• Field of Search: 244/17.27, 244/17.11, 244/17.13, 244/54, 248/550, 416/500, 416/550
• US Class Current: 244/17.13
• CPC Class Codes: B64C 2027/004 using actuators, e.g. active systems
• CPC Class Codes: G05D 19/02 characterised by the use of electric means

Abstract

An active vibration control system including a sensor responsive to a source of vibration and which provides an output signal representative of the vibrations; at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal; a correction subsystem responsive to the actuator for estimating the sensor output in the absence of the canceling vibrations and which outputs a corrected output signal representative only of the vibrations emanating from the source; and a state space predictor responsive to the corrected output signal for determining the input signal to the actuator based on variations in the corrected output signal to better control vibrations especially in chaotic systems.

Claims

1. An active vibration control system comprising:

a sensor responsive to a source of vibration which provides an output signal representative of the vibrations;

at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal;

a correction subsystem responsive to the actuator for estimating the sensor output in the absence of the canceling vibrations and which outputs a corrected output signal representative only of the vibrations emanating from the source; and

a state space predictor responsive to the corrected output signal for determining the input signal to the actuator based on variations in the corrected output signal to better control vibrations especially in chaotic systems.

2. The active vibration control system of claim 1 in which the sensor is an accelerometer.

3. The active vibration control system of claim 1 in which the sensor is physically connected to the source of vibration.

4. The active vibration control system of claim 1 in which the actuator is an electro-hydraulic actuator.

5. The active vibration control system of claim 1 in which there are a plurality of actuators.

6. The active vibration control system of claim 1 in which the actuator is mounted between the source of vibrations and the structure to be isolated from the source of vibrations.

7. The active vibration control system of claim 1 in which the source of vibrations is the rotor, gear box, and engine assembly of helicopter, the sensor is an accelerometer attached to the gear box, and the actuator is positioned between the airframe of the helicopter and the rotor, gear box, and engine assembly.

8. An improved active vibration control system including a source of vibrations, a structure which is impacted by the source of vibrations, a sensor or sensors connected to the structure, an actuator or actuators positioned to impart canceling vibrations to the source;

and an analyzer/control subsystem responsive to the sensor or sensors for driving the actuator or actuators, the improvement comprising;

a sensor to be positioned to detect vibrations directly from the source; and

a software package including;

a correction subsystem responsive to the actuator for estimating the sensor output in the absence of the canceling vibrations and which outputs a corrected output signal representative only of the vibrations emanating from the source; and

a state space predictor responsive to the corrected output signal for determining the input signal to the actuator based on variations in the corrected output signal to better control vibrations especially in a chaotic system.

9. The active vibration control system of claim 8 in which the sensor is an accelerometer.

10. The active vibration control system of claim 8 in which the sensor is physically connected to the source of vibration.

11. The active vibration control system of claim 8 in which the actuator is an electro-hydraulic actuator.

12. The active vibration control system of claim 8 in which there are a plurality of actuators.

13. The active vibration control system of claim 8 in which the actuator is mounted between the source of vibrations and the structure to be isolated from the source of vibrations.

14. The active vibration control system of claim 8 in which the source of vibrations is the rotor, gear box, and engine assembly of helicopter, the sensor is an accelerometer attached to the gear box, and the actuator is positioned between the airframe of the helicopter and the rotor, gear box, and engine assembly.

15. An active vibration control system comprising:

a sensor responsive to a source of vibration which provides an output signal representative of the vibrations;

at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal; and

a correction subsystem responsive to the actuator for estimating the sensor output in the absence of the canceling vibrations and which outputs a corrected output signal representative only of the vibrations emanating from the source.

16. An active vibration control system comprising:

a sensor responsive to a source of vibration which provides an output signal representative of the vibrations;

at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal; and

a state space predictor configured to perform non-linear dynamical analysis on the output signal and configured to determine the appropriate input signal to the actuator based on variations in the output signal to better control vibrations especially in chaotic systems and even though the vibration output signal is unstable.

17. An active vibration control system comprising:

a single sensor responsive to sources of vibrations which provides an output signal representative of the vibrations from the sources;

at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal;

a correction subsystem responsive to the actuator for estimating the sensor output in the absence of the canceling vibrations and which outputs a corrected output signal representative only of the vibrations emanating from the sources; and

a state space predictor responsive to the corrected output signal for determining the input signal to the actuator based on variations in the corrected output signal to better control vibrations especially in chaotic systems.

18. The active vibration control system of claim 17 in which the sources of vibrations are the rotor, gear box, and engine assembly of a helicopter.

19. An active vibration control system comprising:

a sensor responsive to a source of vibration which provides an output signal representative of the vibrations;

at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal;

a correction subsystem responsive to the actuator for estimating the sensor output in the absence of the canceling vibrations and which outputs a corrected output signal representative only of the vibrations emanating from the source; and

a state space predictor configured to perform non-linear dynamical analysis and responsive to the corrected output signal for determining the input signal to the actuator based on variations in the corrected output signal to better control vibrations especially in chaotic systems.

20. An active vibration control system for a helicopter including a rotor blade, said system comprising:

a sensor responsive to a source of vibration which provides an output signal representative of the vibrations;

at least one actuator positioned to impart canceling vibrations to the source of vibrations based on an input signal; and

a state space predictor configured to perform non-linear dynamical analysis for predicting the rotor blade passing frequency component of the rotor blade driving force, said state space predictor responsive to the output signal for determining the input signal to the actuator based on variations in the output signal to better control vibrations.