Vibration reducing device and vibration reducing method

• US 20080134787A1
• Filed: 10/24/2007
• Published: 06/12/2008
• Est. Priority Date: 10/31/2006
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Asahara, Yasuyuki, Sato, Kazuto, Sato, Yusuke
• Granted Patent: US 8,584,820 B2
• Time in Patent Office: Days
• US Class Current: 73/526
• CPC Class Codes: F16F 7/1005 characterised by active control of the mass

Abstract

A vibration reducing device, including an inertial mass actuator adapted to be mounted on a vibration damping object, that applies a vibration damping force on the vibration damping object, the vibration damping force being a reactive force generated due to displacement of an inertial mass. A vibration state detector detects the vibration state of the inertial mass. A controller is connected to the inertial mass actuator and vibration state detector. The controller determines the displacement and velocity of the vibration damping object at a part where the inertial mass actuator is mounted, and the displacement and velocity of the inertial mass, based on the vibration state of the inertial mass. The vibration damping force is controlled based on the determined displacement and velocity of the vibration damping object at the part where the inertial mass actuator is mounted, and the displacement and velocity of the inertial mass.

Claims

1. A vibration reducing device, comprising:

an inertial mass actuator adapted to be mounted on a vibration damping object, that applies a vibration damping force on the vibration damping object, the vibration damping force being a reactive force generated due to displacement of an inertial mass;

a vibration state detector that detects the vibration state of the inertial mass; and

a controller connected to the inertial mass actuator and vibration state detector;

wherein the controller determines the displacement and velocity of the vibration damping object at a part where the inertial mass actuator is mounted, and the displacement and velocity of the inertial mass, based on the vibration state of the inertial mass; and

the vibration damping force is controlled based on the determined displacement and velocity of the vibration damping object at the part where the inertial mass actuator is mounted, and the displacement and velocity of the inertial mass.

2. The vibration reducing device according to claim 1, wherein based on an observer having the displacement and velocity of the vibration damping object at the part where the inertial mass actuator is mounted, and the displacement and velocity of the inertial mass, the controller determines the displacement and velocity of the vibration damping object at the part where the inertial mass actuator is mounted and the displacement and velocity of the inertial mass.

3. The vibration reducing device according to claim 1, wherein the vibration damping force has a component proportional to the relative displacement of the vibration damping object and the inertial mass at the part where the inertial mass actuator is mounted, and to the relative velocity of the vibration damping object and inertial mass at the part where the inertial mass actuator is mounted.

4. The vibration reducing device according to claim 3, wherein the vibration damping force has a component proportional to the velocity of the vibration damping object at the part where the inertial mass actuator is mounted.

5. The vibration reducing device according to claim 4, wherein the vibration damping force has a component proportional to the displacement of the vibration damping object at the part where the inertial mass actuator is mounted.

6. The vibration reducing device according to claim 5, wherein in the component proportional to the velocity and the displacement of the vibration damping object at the part where the inertial mass actuator is mounted, a low frequency component below a prescribed frequency is cut by a high-pass filter.

7. The vibration reducing device according to claim 1, wherein the vibration state detector detects the vibration acceleration of the inertial mass as the vibration state of the inertial mass.

8. The vibration reducing device according to claim 1, wherein the vibration state detector detects the relative displacement of the vibration damping object and inertial mass at the part where the inertial mass actuator is mounted.

9. The vibration reducing device according to claim 1, wherein

the inertial mass actuator includes a force generating element that causes the inertial mass to be displaced with respect to the vibration damping object by changing an length of the force generating element thereof according to a driving signal;

and

the controller makes use of a force conversion coefficient that compensates the relationship correlating the driving signal and the length of the force generating element to determine the driving signal, and identifies the force conversion coefficient based on the driven output signal generated when the length of the force generating element is changed by an external force.

10. The vibration reducing device according to claim 9, wherein the controller identifies the force conversion coefficient based on a characteristic resonance value for the inertial mass actuator computed based on a varied force conversion coefficient, and a predetermined reference characteristic resonance value for the inertial mass actuator.

11. The vibration reducing device according to claim 10, wherein the controller identifies the force conversion coefficient based on the square of the ratio of the characteristic resonance value for the inertial mass actuator computed based on the varied force conversion coefficient to a predetermined reference characteristic resonance value for the inertial mass actuator.

12. The vibration reducing device according to claim 9, wherein

the vibration damping object is a structural member of an engine;

and

the controller identifies the force conversion coefficient when the engine speed is within a prescribed engine speed range where variation in the vibration noise is small with respect to variation in the engine speed.

13. The vibration reducing device according to claim 9, wherein

the vibration damping object is a structural member of an engine;

and

the controller identifies the force conversion coefficient when a crank angle is within a prescribed range where vibration noise is lower by comparison with other crank angles.

14. The vibration reducing device according to claim 9, wherein the force generating element is a piezoelectric element.

15. The vibration reducing device according to claim 9, wherein the force generating element is a super-magnetostrictive element.

16. A vibration reducing device, comprising:

means for applying a vibration damping force on a vibration damping object, the vibration damping force being a reactive force generated due to displacement of an inertial mass;

means for detecting a vibration state of the inertial mass; and

means for controlling the vibration reducing device, that determines the displacement and velocity of the vibration damping object at a part where the means for applying a vibration damping force is mounted to the vibration damping object, and that determines the displacement and velocity of the inertial mass, based on the vibration state of the inertial mass,

wherein the vibration damping force is controlled based on the determined displacement and velocity of the vibration damping object at the part where the means for applying a vibration damping force is mounted, and the displacement and velocity of the inertial mass.

17. A method of reducing vibration of a vibration damping object, comprising:

applying a vibration damping force on the vibration damping object with an inertial mass actuator, the vibration damping force being a reactive force generated due to displacement of an inertial mass;

detecting a vibration state of the inertial mass;

determining the displacement and velocity of the vibration damping object at a part where the inertial mass actuator is mounted to the vibration damping object, and the displacement and velocity of the inertial mass, based on the vibration state of the inertial mass; and

controlling the vibration damping force based on the determined displacement and velocity of the vibration damping object at the part where the inertial mass actuator is mounted, and the displacement and velocity of the inertial mass.