Method and apparatus for extracting a component signal from a composite signal

• US 6,275,591 B1
• Filed: 10/22/1996
• Issued: 08/14/2001
• Est. Priority Date: 10/22/1996
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Lee, Garland, Maillard, Julien, Burdisso, Ricardo Anibal, Fuller, Christopher Robert, Smith, Jerome Peter, Hollingsworth, Larry Duane, Hsueh, Keng D.
• Primary Examiner(s): Harvey, Minsun Oh
• Application Number:
  US08/734,939
• Time in Patent Office: 1,757 Days
• Field of Search: 381/71, 381/94, 381/73.1, 381/86, 381/91.4, 381/71.1, 381/71.2, 381/71.4, 381/71.8, 381/71.11, 381/71.12, 381/71.13, 364/724.19, 375/232, 375/233, 333/165, 333/166, 333/18
• US Class Current: 381/71.11
• CPC Class Codes: G01H 3/08 Analysing frequencies present in complex vibrations, e.g. comparing harmonics present acoustic presence detection G01V1/001
• CPC Class Codes: H03H 21/0012 Digital adaptive filters

Abstract

An extracting assembly for extracting a component signal generated by a component source from a composite signal is disclosed wherein a reference sensor generates a reference signal relating to activity of the component source, a composite sensor senses the composite signal, an adaptive filter is operatively connected to the reference sensor and the composite sensor to filter the component signal from the composite signal as a function of the reference signal generated by the reference sensor, and a normalizer operatively connected to the adaptive filter for normalizing the step size of each iteration taken by the adaptive filter to minimize the time to adapt the adaptive filter to transform the reference signal into the component signal.

Claims

1. An extracting assembly for extracting a component signal generated by a component source from a composite signal of a motor vehicle, said extracting assembly comprising:

a separate reference sensor for generating a separate reference signal relating to activity of the component source;

a separate composite sensor for sensing the separate composite signal;

an adaptive filter operatively connected to said reference sensor and said composite sensor, said adaptive filter filtering the component signal from the composite signal as a function of the reference signal generated by said reference sensor, said adaptive filter utilizing a least-mean-square algorithm to adapt coefficients of said adaptive filter, said adaptive filter being adaptable by an adaptation step having an initial estimated size;

said adaptive filter being updated according to the equation;

2. An extracting assembly as set forth in claim 1 wherein said composite sensor is a microphone.

3. An extracting assembly as set forth in claim 1 wherein said reference sensor is an accelerometer.

4. An extracting assembly as set forth in claim 1 including a speaker operatively connected to said adaptive filter for transforming said component signal into an audible signal.

5. A method for generating a composite signal and extracting a portion thereof generated by a predetermined source using a separate composite sensor and a separate reference sensor in a motor vehicle;

the method comprising the steps of;

generating a reference signal from the reference sensor relating to activity of a component source;

generating a composite signal from the composite sensor;

transmitting the reference signal to an adaptive filter;

transmitting the composite signal to the adaptive filter;

outputting the portion of the composite signal based on the reference signal to be analyzed;

adapting the adaptive filter to remove the portion of the composite signal based on the reference signal by generating an error signal according to the equation;

e(n)=d(n)+N(n)−

{X(n)}^T{W(n−

1)} wherein d(n) is a portion of the composite signal and minimizing the mean square of the error signal and updating the adaptive filter according to the equation;

6. An extracting assembly for extracting a component signal generated by a component source from a composite signal of a motor vehicle, said extracting assembly comprising:

at least one accelerometer for generating a reference signal relating to activity of the component source;

a microphone for sensing the composite signal;

an adaptive filter operatively connected to said at least one accelerometer and said microphone, said adaptive filter filtering the component signal from the composite signal as a function of the reference signal generated by said reference sensor, said adaptive filter utilizing a least-mean-square algorithm to adapt coefficients of said adaptive filter, said adaptive filter being adaptable by an adaptation step having an initial estimated size;

said adaptive filter being updated according to the equation;