Single-channel Active Noise Control Technology

With the continuous development and progress of human society, Noise pollution has increasingly been given attention. Noise will seriously affect the health of people, and will also have an impact on machinery and equipment, lead performance degradation, and shorten the life span. So the noise control technology has been developing rapidly, researchers have done a lot of work about noise control.Noise control technology includes passive noise control technology and active noise control technology, the traditional methods is the passive noise control, including absorption of noise and noise isolation etc. the principle is the use of noise sound waves with acoustic materials or acoustic structure interaction to absorb the energy of noise sound waves.The reflection of human body to sound is evaluated by loudness, when the energy is same, median and low-frequency's sound is loudest, so they affect human more badly; but the passive noise control only has effect on high-frequency noise.In this thesis active noise control technology has been used to solve low-frequency problem, we analyzed common adaptive active noise control algorithms, such as the filtered-x LMS algorithm,and made some simulations. Genetic algorithm also been used in the active noise control to solve many problems in the common algorithm. Due to the secondary sound source installation inconvenience, the virtual position sensor technology been posted in the thesis, through simulation, it makes well.The active noise control platform's hardware uses TI DSP chip, designed sound tube and other hardware. Through microphone to sample the noise, put the noise data to simulation software to analysis, got good noise reduction.