Research On Sound Source Localization Based On Wireless Sensor Network

The noise pollution is an important part of the modern environmental pollution,therefore, the environmental noise monitoring has become really important as ameans of the evaluation on the environment. The conventional noise monitoringtransmits the collected data by wired medium that causes a few shortcomings, suchas the difficulties of cablecasting and the high cost. Thus the current researchfocuses on the noise monitoring based on wireless sensor network because of thesmaller cost, the easier cabling, the higher precision and the more powerfulsynergy.To locate the noise source is a key technology in the noise monitoring. Inorder to achieve the localization of the noise source in the environment of publicplaces, further research on sound source localization based on time delay estimationis needed in this subject.The algorithm on time delay estimation is the main emphasis of the soundsource localization algorithm. The traditional time delay estimation method wasparticularly studied and simulated in this thesis. According to these analyses, thethesis presented a improved PHAT-GCC time delay estimation method based on thearc tangent transformation. The method still has a good stability even in the publicplaces when the background noise of the public places is non-Gaussian noise. Thenthe thesis introduced three kinds of localization algorithm based on time delayestimation, and focused on the error analysis and comparison between two spatialarrangements of the angles and distances localization method.Finally, this thesis designed a sound source localization system based onwireless sensor network. The CC2430chip is the core of the sensor node in thissystem. The system is tested combined with the improved time delay estimationalgorithm and the five-element array localization algorithm. The experimentalresults are presented and analysed. The experiments show that the sound sourcelocalization system is practical and available to achieve the localization of the noisesource in public places.