Chung Yuan Christian University

Sen-Maw Kuo

Cheng-Yuan Chang

Wei Chun Hsu

Chong-Rui Huang

A design method for feedforward active noise control (ANC) system using analog filter. In which, at least one noise collecting system is adopted for collecting a real environmental noise for obtaining a reference signal and a target signal. According to the reference signal and the target signal, a first adaptive system identifying unit is enabled to complete a system identification process for producing a first adaptive filter. After that, a second adaptive system identifying unit is enabled to complete a system identification process based on the reference signal, the target signal and the first adaptive filter for producing a second adaptive filter. After the second adaptive filter is converted to a low-order digital filter, the digital filter is further converted to a physical analog filter circuit. Consequently, a feedforward ANC system comprising the physical analog filter circuit, a pre-amplifier unit, a reference microphone, and a mixer is established.

Method for feedforward active noise control system using analog filter

A design method for feedforward active noise control system is disclosed. Based on a target signal and a reference signal, a first adaptive system identifying unit is enabled to complete a first system identification process for producing a first adaptive filter, and then a second adaptive system identifying unit is enabled to complete a second system identification process for producing a second adaptive filter. After the second adaptive filter is converted to a digitally-controlled filter by using a system identification tool, the digitally-controlled filter is implemented into a DSP chip of a feedforward active noise control system. As a result, it is able to find that not only the computing loading of the DSP chip is significantly lowered while an adaptive algorithm executes an active noise control computing, but also the feedforward active noise control system exhibits a broad frequency bandwidth noise cancelling ability.

Method for feedforward active noise control system

Disclosures of the present invention describe a portable smart electronic device, which consists of several first reference microphones, a first loudspeaker, a first error microphone, several of second reference microphones, a second loudspeaker, a second error microphone, and a noise controlling module. Both the first error microphone and the second error microphone are set to have a noise detection direction and face to a first region near to a right ear and a second region near to a left ear, respectively. Therefore, the noise detection direction and an audio broadcasting direction of both the first loudspeaker and the second loudspeaker have a same progress direction. By such arrangement, this portable smart electronic device can be operated to adaptively provide an anti-noise audio to the first region and the second region for establishing a quiet zone in both the two regions by attenuating various environment noises.

Portable smart electronic device for noise attenuating and audio broadcasting

The present invention discloses a fan noise controlling system, comprising: at least one cylinder-shaped limiter, a plurality of error sensors, a noise controlling module, and at least one loudspeaker. According to the particular design of the present invention, the cylinder-shaped limiter is connected to a fan device for confining the transmission path of at least one fan noise signal. On the other hand, the error sensors are disposed in the internal of the cylinder-shaped limiter, and the loudspeaker is disposed at an axis position of the fan device. When this fan controlling system normally works, the noise controlling module is able to generate at least one anti-noise signal according to a plurality of error signals collected by the error sensors at consecutive previous time points, and then the loudspeaker is driven to broadcast the anti-noise signal for carrying out an outstanding efficacy on the cancellation of the fan noise.

Fan noise controlling system

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.

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

The present invention provides an electronic helmet for cancelling noises, which comprises a helmet including a plurality of microphones, a plurality of speakers and a first communication unit; and a mobile device including a second communication unit and a control unit. When the first communication unit in the helmet connects to the second communication unit in the mobile device, the control unit generates a plurality of control signals according to at least one sound or noise detected by the plurality of microphones. The mobile device uses the plurality of control signals to control the plurality of speakers outputting the at least one sound or anti-noise cancelling the noise. By the above electronic helmet, the present invention also provides a method integrating active noise control, hands-free communication, music listening, and voice navigation so as to achieve the proposes of cancelling the noises and improving the riding quality.

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Taoyuan, Taiwan

Sen-Maw Kuo