A Study On Sound Source Track Technology Based On Virtual Instrument

Sound source localization technology has great potential application value. It can be used not only in the military field, such as locating the sniper, tracking low-altitude or ground targets, etc.,but also in civilian field, such as enhancing sound in large venues, holding video conference and recording news television and so on. In addition, it also has important significance in the study of earthquake monitoring and in tracking underwater target. The microphone or camera track the sound target by positioning the sound and achieve sound recording amplification matching or camera rotation to focus, which helps to capture high resolution and high definition voice or screen. In recent years, sound source localization has been widely studied.This paper discusses the common algorithm of sound source localization and the layout model of microphone array, especially the sound source localization technology based on time difference of arrival(TDOA). Besides, four element cross structure microphone array model and generalized cross correlation(GCC) time delay estimation algorithm are also analyzed. The positioning technology of TDOA and GCC algorithm is specifically studied based on the fact that the current sound source tracking is insufficient in real-time, fast, and the positioning accuracy. The key premise of sound source localization algorithm based on TDOA is the minimum error of the time delay. When factors affecting the accuracy of the GCC algorithm in the calculation of time delay distortion is analyzed, it can be drawn in this way:the reverberation in sensor receives signal has an effect on its precision loss. The technology of dereverberation on complex cepstrum domain for removal of reverberation from reverberation in acoustic wave is proposed according to the characteristics of reverberation and the method of reverberation. Thus it can improve the insufficiency of GCC algorithm on reverberation removal, reduce the error of the GCC algorithm for time delay calculation and improve the calculation accuracy of the arrival time difference of two acoustic signals, thus further reducing the error generated form the sound source localization algorithm based on TDOA to the localization.A source tracking system of cross structure layout into four pick-up array based on virtual instrument was designed and implemented in this paper. The completion of system of sound source localization based on TDOA algorithm and the improved GCC time delay estimation algorithm can effectively manage the granary by tracking the target according to its sound such as the sound of birds, bandicoot or any sound like that. Furthermore, the design of sound source tracking system hardware and software based on platform of LabVIEW2012, four synchronous data acquisition card NI USB-9234 and four element cross array structure was introduced in detail. The system can achieve the function of parameter settings, the sound source coordinate real-time access, file storage, and three-dimensional numerical dynamic display and remote monitoring. The test shows that the system can achieve the positioning of the moving target and has a strong human-computer interaction. Finally, the system error analysis was made and experimental results show that the system has high time-efficiency, high accuracy, low computation and good stability. And results also prove that the improved algorithm has a certain improvement on the positioning accuracy of the system, which also possesses lower computation and better real-time performance.