基于DSP的有源噪声控制系统研究

发布时间：2018-06-25 15:38

本文选题：有源噪声控制 + LMS自适应算法　；参考：《内蒙古工业大学》2013年硕士论文

【摘要】：被世界公认为第三大公害的是噪声污染，噪声污染是现在十分关注的环境问题，若长期在低频噪声环境下工作、学习或生活，将对人的身体健康造成严重危害。在军事领域，某些技术兵器的作战性能也和噪声问题息息相关。有源噪声控制技术又被称为主动噪声控制（Active Noise Control，ANC）技术，它是以声波的干涉现象为原理以实现降噪为目的的一种方法，近几年来由于人们生活质量的提高所以降噪问题又成为了研究热点。在有源噪声控制中，我们想要的输出已经有了明确的要求，即是要和噪声频率相同，幅值相同，相位相差180°，而噪声源是未知的，所以我们这里就要让滤波器的参数根据前一时刻的值，自动调节参数来适应噪声源的变化产生我们想要的输出，，也就是我们的自适应算法。由于最小均方(LMS)自适应算法比较简单、易于实现，本文搭建实现了一个基于LMS算法的单通道有源噪声控制系统及一个和上位机联合控制的单通道有源噪声控制系统。一般情况下，某一局部空间的噪声可以认为是若干复频声源信号从不同的传播方向经过不同的传递通道在此空间范围内的合成结果。这些噪声源信号通常是具有一定带宽的强相关信号，即它们具有相同的频率成分。在这样复杂的噪声信号条件下，目前采用LMS算法的双通道控制系统降噪效果甚微，本文又设计搭建了一个基于信号盲分离算法的双通道控制系统。本文选用的是TMS320VC5509ADSP数字信号处理器，该款芯片在语音识别及语音合成等方面所用到的数字信号处理算法是十分有效的。实验结果表明，基于LMS算法的单通道降噪系统效果最好时可以取得1dB(A)左右的降噪效果，和上位机联合控制的单通道有源噪声控制系统可以取得13~16dB(A)的降噪效果，基于信号盲分离算法的双通道降噪系统可以取得8~10dB(A)左右的降噪效果，本文最后对这几种系统做了总结和分析提出了改进的办法。
[Abstract]:Noise pollution is recognized as the third major public hazard in the world. Noise pollution is a serious environmental problem. If we work, study or live in low-frequency noise environment for a long time, it will cause serious harm to human health. In the military field, the combat performance of some technical weapons is also closely related to the noise problem. The active noise control technology is also called Active noise Control (ANC) technology. It is a method based on the interference phenomenon of sound wave to achieve noise reduction. In recent years, due to the improvement of people's quality of life, noise reduction has become a research hotspot. In the active noise control, the output we want has a clear requirement, that is, the noise frequency is the same, the amplitude is the same, the phase difference is 180 掳, and the noise source is unknown. So we have to let the parameters of the filter automatically adjust the parameters according to the value of the previous time to adapt to the change of noise source to produce the output we want, that is, our adaptive algorithm. Because the least mean Square (LMS) adaptive algorithm is simple and easy to implement, a single channel active noise control system based on LMS algorithm and a single channel active noise control system based on LMS algorithm are built and implemented. In general, the noise in a local space can be considered as the composite result of a number of complex frequency sound source signals passing through different transfer channels in this space from different propagation directions. These noise source signals are usually strong correlated signals with certain bandwidth, that is, they have the same frequency components. Under such complicated noise signal condition, the noise reduction effect of two-channel control system based on LMS algorithm is very little. In this paper, a dual-channel control system based on blind signal separation algorithm is designed and built. In this paper, TMS320VC5509ADSP digital signal processor is selected. The digital signal processing algorithm used in speech recognition and speech synthesis is very effective. The experimental results show that the single channel noise reduction system based on LMS algorithm can achieve a noise reduction effect of about 1 dB (A) when the effect is the best, and a single channel active noise control system controlled by a host computer can achieve a noise reduction effect of 13 ~ 16 dB (A). The two-channel de-noising system based on blind signal separation algorithm can achieve a noise reduction effect of about 8 ~ 10dB (A). In the end, this paper summarizes and analyzes these systems and puts forward some improved methods.
【学位授予单位】：内蒙古工业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TB535

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