Noise controller which noise-controls movable point
First Claim
1. A noise controller which noise-controls a movable point so that noise generated from a noise source and transmitted to the movable point can be reduced, said noise controller comprising:
- a) noise detecting means, located near the noise source, for detecting the noise, and for generating a first signal representing the noise;
b) signal processing means including a digital filter which has a filter coefficient, coupled to said noise detecting means, for generating a second signal by signal-processing the first signal via the digital filter;
c) antinoise generating means, coupled to said signal processing means, for (1) generating an antinoise from the second signal and for (2) outputting the antinoise to the movable point so as to cause the antinoise to collide with the noise;
d) residual-noise detecting means, located at the movable point, for detecting residual noise generated from the noise which was made to collide with the antinoise, and for generating a third signal representing the residual noise;
e) position detecting means for detecting a position of the movable point; and
f) coefficient renewing means, coupled to said residual-noise detecting means and responsive to said position detecting means, for renewing the filter coefficient of the digital filter in said signal processing means based on the position of the movable point detected by the position detecting means so that the movable point can be properly noise-controlled even when the movable point moves, said coefficient renewing means renewing the filter coefficient in accordance with a least mean square algorithm in which the filter coefficient is renewed so that a squared third signal can be minimized.
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Abstract
A noise controller which noise-controls a movable point so that a noise generated from a noise source and transmitted to the movable point can be reduced. The noise controller filters the noise in accordance with a least mean square algorithm and generates an antinoise to be collided with the noise so that the antinoise and the noise can cancel each other out. When a filter coefficient used for the least mean square algorithm is renewed, the noise controller uses position data of the movable point. Thus, even if the movable point moves, the proper noise-control can be performed.
44 Citations
15 Claims
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1. A noise controller which noise-controls a movable point so that noise generated from a noise source and transmitted to the movable point can be reduced, said noise controller comprising:
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a) noise detecting means, located near the noise source, for detecting the noise, and for generating a first signal representing the noise; b) signal processing means including a digital filter which has a filter coefficient, coupled to said noise detecting means, for generating a second signal by signal-processing the first signal via the digital filter; c) antinoise generating means, coupled to said signal processing means, for (1) generating an antinoise from the second signal and for (2) outputting the antinoise to the movable point so as to cause the antinoise to collide with the noise; d) residual-noise detecting means, located at the movable point, for detecting residual noise generated from the noise which was made to collide with the antinoise, and for generating a third signal representing the residual noise; e) position detecting means for detecting a position of the movable point; and f) coefficient renewing means, coupled to said residual-noise detecting means and responsive to said position detecting means, for renewing the filter coefficient of the digital filter in said signal processing means based on the position of the movable point detected by the position detecting means so that the movable point can be properly noise-controlled even when the movable point moves, said coefficient renewing means renewing the filter coefficient in accordance with a least mean square algorithm in which the filter coefficient is renewed so that a squared third signal can be minimized. - View Dependent Claims (2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15)
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8. A noise controller which noise-controls a predetermined point so that noise generated from a noise source and transmitted to the predetermined point can be reduced, said noise controller comprising:
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a) noise detecting means, located near the noise source, for detecting the noise, and for generating a first signal representing the noise; b) first single processing means including a first digital filter which has a filter coefficient, coupled to said noise detecting mean, for generating a second signal by signal-processing the first signal via the first digital filter; c) antinoise generating means, coupled to said first signal processing means, for (1) generating an antinoise from the second signal and for (2) outputting the antinoise to the predetermined point so as to cause the antinoise to collide with the noise; d) residual-noise detecting means, located at the movable point, for detecting a residual noise generated from the noise which was made to collide with the antinoise, and for generating a third signal representing the residual noise; e) position detecting means for detecting a position of the movable point; f) process memory means, coupled to said first signal processing means, for storing therein a just previously renewed filter coefficient; and g) first coefficient renewing means, coupled to said residual-noise detecting means, said position detecting means, and said process memory means, for renewing, while converging, the filter coefficient of the first digital filter in accordance with a least mean square algorithm, by using the just previously renewed filter coefficient stored in said process memory so as to quickly converge the filter coefficient, in which least means square algorithm the filter coefficient of the first digital filter is renewed so that a squared third signal can be minimized. - View Dependent Claims (9)
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Specification