Active noise control helmet

• Main Authors: Chun-Jen Huang, 黃俊仁
• Other Authors: Cheng-Yuan Chang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/17571957574292780209

碩士 === 中原大學 === 電機工程研究所 === 99 === Abstract The topic for this research is “Active Reduce Noise Control Helmet,” this idea is basic on “Active Noise Control,” which means can avoid or keep away the acoustic from the noisy environments. In particular, advances in technology to facilitate life there are much noise pollution surrounding in transportation vehicle and industry-wide environments’. It is inevitable that noise pollution will affect our physical and psychological harm. The “Active Reduce Noise Control Helmet” is not public to use, because it is costly, currently use in aviation to protect the people who works in this area; The idea of “Active Reduce Noise Control Helmet,” is become increasingly in everywhere; and also the digital signal process this idea is useful in Digital Signal Processor (DSP) platform, it is because DSP has a powerful data processing capability and high operation speed, so that can make ANC do real-time data operations to make it easier to achieve. However not only DSP can be achieve to ANC, in this practical research will use Micro-Controller Unit (MCU) instead MCU-DSP, the advantage will less than one-sixth of the price. In algorithm does not use Reference microphone but use Error microphone and it is used in the framework Feedback FXLMS; So, the Error microphone location’s sound-field frequency response is really important, it will affect Secondary path’s calculate and noise reduction collection quality, then make MCU designer have better noise reduction quality. In conclusion will known the noise reduction ability will eliminate low-frequency noise over than 8dB, and motorcycle riding in the recording of the noise, there is 5dB noise reduction.