Research And Implementation Of Sound Source Orientation System Based On Microphone Arrays

Sound source location based on microphone arrays has a broad prospect ofapplications in hearing aids, military defense and intelligent robot etc. With the progress ofscience and technology, electronic devices are gradually becoming smaller. How constructa miniaturized sound source location system with low cost, simple structure and highestimation precision of direction of arrival (DOA) has been received a growing interest. Invarious source location methods, the time difference of arrival (TDOA) based on thedouble step method is the most widely used in the large scale system of sound sourcelocation, but its application in the small scale system was restricted by its large amount ofcomputation. So the paper focuses on this method and makes it can be implemented on8-bit microcontroller by optimizing the method.Firstly, for the sound source localization based on time delay estimation, Detaileddiscusses five common time delay estimation methods, derivation of formula and analyzestheir advantages and applications.Secondly, GCC filters the signal by frequency domain weighting function. Howeverit can not be implemented on8-bit microcontroller because of memory constrained. Forthe specific audio signal, a new delay estimation algorithm based on cross-correlation withmatched filter is proposed and applied to audio signal delay estimation based on8-bitmicrocontroller. Taking into the small memory of the8-bit microcontroller, the proposedmethod optimizes the algorithm and compresses the requirements of memory and thecomputation by the combination of matched filter and cross-correlation.Then, based on STC12C5A16AD MCU experimental plate, designed a toy controllerbased on8-bit microcontroller with the function of voice recognition and direction-finding.The characteristics of the controller are receiving the sound signals based on themicrophone arrays and checking the sound、before and after identification、patternrecognition、direction of arrival based on8-bit microcontroller. The delay estimationmethod adopts the algorithm based on cross-correlation with matched filter.Finally, do a great amount of experiments in a real environment, the experimentalresults show that the system algorithm is simple, little computations. At the same time, the system performance better real-time and anti-noise ability. So it can be used in real timepositioning system.