Active noise cancellation system utilizing a signal delay to accommodate noise phase change
First Claim
1. A noise cancellation system, comprising:
- a nonacoustic sensor that provides a signal indicating a position or frequency of a source of noise;
an actuator that is adapted to provide a noise cancellation signal and is positioned a distance from the source of noise;
a signal generator that is responsive to the signal from the sensor and provides a noise canceling reference signal to cause the actuator to produce the noise cancellation signal, the signal generator adjusting the phase of the reference signal corresponding to a phase change that occurs as the noise travels from the source to the speaker location.
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Accused Products
Abstract
An active noise cancellation system (20) for use with an assembly (22) includes adjusting the phase of a reference signal an amount that corresponds to a change in phase of the noise (26) within the system. A non-acoustic sensor (44) provides a signal regarding a position or frequency of a source of noise (28) (i.e., RPM'"'"'s of a vehicle engine). Control electronics (32) provide a reference signal to the system noise canceling actuator (30) (i.e., a speaker) that includes the phase adjustment responsive to the sensor signal. In one example, the reference signal is delayed an amount of time corresponding to the phase change in the noise (26) as it travels through the system (22). In another example, the phase angle is adjusted.
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Citations
13 Claims
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1. A noise cancellation system, comprising:
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a nonacoustic sensor that provides a signal indicating a position or frequency of a source of noise;
an actuator that is adapted to provide a noise cancellation signal and is positioned a distance from the source of noise;
a signal generator that is responsive to the signal from the sensor and provides a noise canceling reference signal to cause the actuator to produce the noise cancellation signal, the signal generator adjusting the phase of the reference signal corresponding to a phase change that occurs as the noise travels from the source to the speaker location. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method of controlling a noise cancellation system having a nonacoustic sensor that provides a signal indicating a position or frequency of a source of noise, an actuator positioned a set distance from the source of noise and a signal generator that provides a noise canceling reference signal responsive to the signal from the sensor, comprising the steps of:
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determining a phase change in the noise as the noise travels from the source to the speaker location; and
adjusting the phase of the reference signal an amount corresponding to the phase change. - View Dependent Claims (9, 10, 11, 12, 13)
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Specification