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Patent 8019090 Click For Printable Version of This Patent
Patent Information:  USPTO Site Listing

Patent Number: 8019090
Case ID: 0
Patent Title: Active feedforward disturbance control system
Status: ACTIVE
Status Date: 9/23/2011 8:43:44 AM
Issue Date: 9/13/2011
Filed Date: 2/12/2009
Serial #: 2/369,903
Assignee Name: United States of America as represented by the Secretary of the Navy (Washington, DC)
Inventor(s): Agrawal, Brij N. , Sugathevan, Suranthiran
Lab Information:  View Lab Profile

Lab Name: Naval Postgraduate School
Location: Halligan Hall, Room 222
Monterey, CA 93493-5000
Contact: Contact Lab About This Patent
   
Description:
BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to signal processing to reduce the effects of noise and particularly to a Least Mean Square (LMS) vibration/noise control algorithm. Still more particularly to a Least Mean Square vibration/noise control algorithm that eliminates the requirement for a reference sensor to generate a reference signal.

2. Description of the Related Art

Active noise or disturbance attenuation has been a high priority issue for many years for applications such as acoustic systems and industrial equipment. The advance of optical laser systems and their increased usage in satellites, space missions, imaging systems, communication and many military applications have established a new trend towards a more critical look at active disturbance control systems. Ever growing demands such as arc-second accuracy and nano-radian jitter require precise and efficient control systems. The growing . . . . More
Abstract:
Noise effects in a signal for driving a plant are reduced by generating a reference signal from the error signal. A signal generator generates a reference signal for input to a finite impulse response (FIR) filter. The error signal is produced by differencing the transfer function output and a disturbance signal. The error signal is input to the signal generator and to a least mean square calculator. The reference signal is input to a copy of the transfer function that outputs a modified reference signal. The modified reference signal is input to least mean square calculator. An LMS signal that updates the filter coefficients to minimize the mean square error is calculated and the LMS signal and the reference signal are input to the FIR filter with the FIR filter being arranged to process the LMS signal and the reference signal to minimize the error signal.
Claims:
What is claimed is:

1. A signal processing method for reducing noise effects by using an error signal to generate a reference signal to compensate for an error signal input to drive signal to a plant, comprising the steps of: generating a reference signal x(n) with a signal generator; inputting the reference signal to a finite impulse response (FIR) filter that produces a filter output signal y(n); producing an error signal e(n) by differencing the transfer function output and a disturbance signal d(n); inputting the error signal to the signal generator and to a least mean square calculator; inputting the reference signal to a copy of the transfer function that outputs a modified reference signal x''(n); calculating an LMS signal that is filter coefficients to minimize mean square error signal; and inputting the LMS signal and the reference signal to the FIR filter, the FIR filter being arranged to process the LMS signal and the reference signal to minimize the error sig . . . . More