Active vibration control system using on-line system identification with enhanced noise reduction

• US 6,229,898 B1
• Filed: 12/23/1998
• Issued: 05/08/2001
• Est. Priority Date: 12/23/1998
• Status: Expired due to Term

• Current Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Original Assignee: Sikorsky Aircraft Corporation (Martin Marietta Corporation)
• Inventors: Goodman, Robert K.
• Primary Examiner(s): Mei, Xu
• Application Number:
  US09/219,817
• Time in Patent Office: 867 Days
• Field of Search: 381/71.4, 381/71.1, 381/71.3, 381/71.9, 381/71.11, 381/71.12, 381/71.13, 381/FOR 123, 381/86, 381/94.1, 381/FOR 12, 381/94.3, 381/94.2, 702/189, 702/190, 702/191, 702/196, 708/300, 708/322, 415/119
• US Class Current: 381/71.4
• CPC Class Codes: B60G 2400/206 Body oscillation speed; Body vibration frequency
• CPC Class Codes: B60G 2600/1871 Optimal control; Kalman Filters
• CPC Class Codes: B60G 2800/162 Reducing road induced vibrations
• CPC Class Codes: B64C 2027/004 using actuators, e.g. active systems
• CPC Class Codes: F16F 15/02 Suppression of vibrations of non-rotating, e.g. reciprocating systems; Suppression of vibrations of rotating systems by use of members not moving with the rotating systems F16F15/005 takes precedence ; layered products B32B; suppression of vibration in ships B63; relieving load on bearings, using magnetic means F16C39/06
• CPC Class Codes: G05D 19/02 characterised by the use of electric means

Abstract

A system for enhancing vibration reduction in a vehicle that utilizes one or more sensors which sense ambient vibration in the vehicle and generate a signal corresponding to the sensed vibrations. A control circuit is coupled to the sensors and receives the signals. The control circuit, utilizing Kalman filtering algorithms, generates a control signal that adapts a previous command force, from an actuator to a sensor, thereby dynamically updating a parameter that represents an estimated vehicle response. This dynamically updated parameter is a result of utilizing a covariance that is a function of an empirically derived constant value and a change in forces exerted by the actuator. The control circuit outputs this control signal to vibration generator units, which generate a vibration field for reducing vibrations in the vehicle.

Claims

1. A system for improving the response of a vehicle to sensed condition comprising:

at least one sensor, mounted in the vehicle, for generating successive first and second ambient vibration signals corresponding to first and second sensed conditions;

at least one actuator, mounted on the vehicle, for generating an actuator force that is applied to the vehicle;

a data module coupled to the sensor and the actuator for storing data, correlating at least one actuator force with at least one sensor response to the force;

a control circuit, including a Kalman filter, for receiving the first and second ambient vibration signals in succession from the sensor and receiving the stored data from the data module, and transmitting a first control signal to an associated actuator corresponding to the first ambient vibration signal;

wherein the control circuit utilizes Kalman filtering and a covariance value, that is a function of an actuator force, to modify data in the data module; and

the control circuit transmits a second control signal that is a function of the second ambient vibration signal and the modified data of the data module.

2. The system of claim 1 wherein the at least one actuator generates a vibration field for reducing sensed ambient vibrations in the vehicle in response to the first and second control signals transmitted from the control circuit.

3. The system of claim 1 wherein the ambient vibration signals are stored as a sensor matrix;

the actuator forces are stored as an actuator matrix; and

the data in the data module is stored as data matrix.

4. The system of claim 3 wherein the elements of the data matrix are identified by a Kalman equation of the form:

5. The system of claim 4 wherein the covariance (R) equals:

6. The system of claim 1 wherein the data module and the control circuit are stored in a microprocessor.

7. The system of claim 1 wherein the vehicle is a helicopter.

8. A system stored on a computer-readable medium for reducing noise in a vehicle comprising:

sensing ambient vibration in the vehicle;

generating an ambient vibration signal that corresponds to sensed ambient vibration;

processing the ambient vibration signal to produce a control signal, the control signal being a function of a dynamic covariance corresponding to a constant value divided by a change in actuator force raised to an integer power;

outputting the control signal to an actuator; and

generating a vibration field for ambient vibration reduction that is a function of the control signal.

9. The system as claimed in claim 8 further comprising:

storing a plurality of ambient vibration signals in a sensor matrix;

storing a plurality of control signals in a data matrix;

storing a plurality of actuator forces in an actuator matrix; and

modifying an element of the data matrix as a function of an actuator force.