Waste air exhausting device having functionality to abate noise and modulate noise frequency

Patent metadata

Field	Value
Publication number	US-10119441-B2
Application number	US-201615230006-A
Country	US
Kind code	B2
Filing date	Aug 5, 2016
Priority date	Mar 16, 2016
Publication date	Nov 6, 2018
Grant date	Nov 6, 2018

Abstract

Differing from conventionally-used exhaust pipe utilizing discontinuous section area(s) and sound-absorbing material(s) to abate the noise produced by an engine, the present invention provides a waste air exhausting device consisting of: a housing, a supporting plate disposed in the housing, a miniature microphone disposed at the end of the housing, and a loudspeaker disposed on the supporting plate. Therefore, according to the noise produced by the engine, a noise controller system coupling to the miniature microphone and the loudspeaker is able to produce an anti-noise signal through the loudspeaker for abating the engine noise. On the other hand, the noise controller system can also produce an anti-noise signal having specific frequencies components according to the frequency of the engine noise and a reference signal, so as to modulate the frequency of the engine noise by broadcasting the anti-noise signal having the specific frequencies components in the housing through the loudspeaker.

First claim

What is claimed is:

1. A waste air exhausting device having functionality to abate noise and modulate noise frequency, comprising:
a housing, being provided with a first opening and a second opening on two ends thereof;
a supporting plate, being disposed in the housing for forming a first space and a second space in the housing 10 , and having at least one installing hole and one through hole thereon;
an air exhausting pipe, being disposed in the housing by passing through the through hole of the supporting plate; wherein the air exhausting pipe has an air inlet end and an air outlet end respectively extending out of the housing via the first opening and the second opening, and the air inlet end of the air exhausting pipe being used for connecting to an exhaust port of an external engine;
at least one loudspeaker, being disposed in the second space by connecting to the installing hole, so as to face the second opening of the housing;
a noise sensing module, being disposed near to the exhaust port of the external engine for receiving an engine speed signal of the external engine or a noise signal produced during the external engine outputting a waste air by the exhaust port;
an error signal sensing module, being disposed in the second space of the housing and adjacent to the air outlet end of the air exhausting pipe so as to face the least one loudspeaker; and
a noise controller, comprising:
a first input end, being connected to the noise sensing module;
an output end, being electrically connected to the loudspeaker; and
a second input end, being electrically connected to the error signal sensing module;

wherein the noise controller is configured to produce an analog anti-noise signal according to the noise signal, and the analog anti-noise signal being then broadcasted in the second space of the housing by the loudspeaker for reducing, so as to reduce the noise level of the noise signal;
wherein the error signal sensing module subsequently collects a remaining noise signal after a noise reduction is carried out between the analog anti-noise signal and the noise signal, and then transmits the remaining noise signal to the noise controller, such that the noise controller applies an adaptive modulation to the analog anti-noise signal according to the remaining noise signal;
wherein noise controller is able to output an analog noise-modulating signal according to a reference signal and the engine speed signal, and broadcasting the analog noise-modulating signal by the loudspeaker, so as to modulate the noise signal to the reference signal.

2. The waste air exhausting device of claim 1 , further comprising a plurality of supporting ribs, being formed in the housing and locating around the first opening and the second opening, used for supporting the air exhausting pipe.

3. The waste air exhausting device of claim 1 , wherein the housing is made of stainless steel material.

4. The waste air exhausting device of claim 1 , wherein the noise sensing module comprises a miniature microphone and a tachometer.

5. The waste air exhausting device of claim 1 , wherein the error signal sensing module is an error microphone.

6. The waste air exhausting device of claim 1 , wherein the noise controller is selected from the group consisting of: digital signal processor and microprocessor.

7. The waste air exhausting device of claim 1 , wherein the analog anti-noise signal and the noise signal have a phase difference of 180 degree.

8. The waste air exhausting device of claim 1 , wherein the noise controller further comprises:
a main processor, being able to receive the noise signal or the engine speed signal from the first input end, and then correspondingly produce a digital anti-noise signal or a digital noise-modulating signal;
a digital-to-analog processing module, being coupled to the main processor for receiving the digital anti-noise signal or the digital noise-modulating signal, so as to convert the digital anti-noise signal and the digital noise-modulating signal to the said analog anti-noise signal and the said analog noise-modulating signal, respectively;
a first analog-to-digital processing module, being coupled to the main processor and the noise sensing module, used for converting the noise signal or the engine speed signal transmitted from the noise sensing module to a digital noise signal; and
a second analog-to-digital processing module, being coupled to the main processor and the error signal sensing module, used for converting the remaining noise signal transmitted from the error signal sensing module to a digital remaining noise signal.

9. The waste air exhausting device of claim 8 , wherein the first analog-to-digital module comprises:
a first pre-amplifier for pre-amplifying the noise signal;
a first antialiasing filter for filtering high-frequency noises carried by the noise signal; and a first analog-to-digital converting unit for converting the noise signal to the digital noise signal.

10. The waste air exhausting device of claim 9 , wherein the main processor comprises:
a first transfer function estimating unit, being coupled to the first analog-to-digital processing module for filtering the digital noise signal, so as to output a filtered noise signal;
an adaptive filter, being connected to the first analog-to-digital processing module for receiving the digital noise signal, and then treating the digital noise signal with an impulse response filtering process; and
an adaptive algorithm unit, being connected to the adaptive filter; wherein the adaptive algorithm unit is able to receive the digital remaining noise signal outputted by the second analog-to-digital processing module and the filtered noise signal outputted by the first transfer function estimating unit, so as to calculate a modulation weight for the adaptive filter, such that the adaptive filter outputs a modulated digital anti-noise signal according to the modulation weight.

11. The waste air exhausting device of claim 10 , wherein the adaptive algorithm unit comprises a specific algorithm selected from the group consisting of: least mean square (LMS) algorithm, normalized least mean square (NLMS) algorithm and others algorithm.

12. The waste air exhausting device of claim 9 , wherein the second analog-to-digital processing module comprises:
a second pre-amplifier for pre-amplifying the remaining noise signal;
a second antialiasing filter for filtering high-frequency noises carried by the remaining noise signal; and
a second analog-to-digital converting unit for converting the remaining noise signal to the digital remaining noise signal.

13. The waste air exhausting device of claim 9 , wherein the digital-to-analog processing module comprises:
a digital-to-analog converting unit, being used for respectively converting the digital anti-noise signal and the digital noise-modulating signal to the analog anti-noise signal and the analog noise-modulating signal;
a reconstruction filter for treating the analog anti-noise signal and the analog noise-modulating signal with a reconstruction process; and
an amplifier for amplifying the analog anti-noise signal and the analog noise-modulating signal.

14. The waste air exhausting device of claim 8 , wherein the first analog-to-digital processing module comprises:
a synchronous signal generator, being used for receiving the engine speed signal, so as to synchronously produce multi analog noise signal according to the engine speed signal; and
a first analog-to-digital processing unit, being coupled to the synchronous signal generator for converting the multi analog noise signal to multi digital noi

Assignees

• Univ Chung Yuan Christian

Inventors

• Chang Cheng-Yuan
• Kuo Sen-Maw

Classifications

• G10K11/17881

  the reference signal being an acoustic signal, e.g. recorded with a microphone · CPC title

• G10K11/1781

  characterised by the analysis of input or output signals, e.g. frequency range, modes, transfer functions · CPC title

• G10K11/17853

  of the filter · CPC title

• G10K11/178

  by electro-acoustically regenerating the original acoustic waves in anti-phase · CPC title

• G10K2210/3028

  Filtering, e.g. Kalman filters or special analogue or digital filters · CPC title