Research On Acoustic Source Localization Protocol Based On Sensors Collaboration In WSNs

Wireless sensor network is a product of information technology. It combines the sensors, embedded computing, distributed information processing and wireless communication technology, which is a new technology of information acquisition and processing. Acoustic source localization in Wireless sensor networks has characteristics of universal adaptability, concealment and robustness. Acoustic source localization in Wireless sensor networks refers to use source target information detected by multiple sensor nodes to estimate the source location at a certain moment, which is a hot research at present. Acoustic source localization based on wireless sensor networks may needs precise time synchronization, the high cost of sensor array, large computation or precise collection of voice signal, which have limited the application of acoustic source localization in wireless sensor network. In order to solve these problems, this paper studies an acoustic source localization based on multi-sensor collaboration, and testing the protocol on analysis of hardware. This protocol does not need time synchronization, less computing, and don't need precise collection of voice signal, only need to monitor the sound signal, and have very good real-time.In this paper, the main content and innovations as follows:(1) This paper presents an acoustic source localization protocol based on multi-sensor collaboration. The main idea is: The protocol finds nodes recently from the sound source first, uses centered position of the nodes as the approximate location of sound source. This paper takes into account the responding time of sound and RF signals processing for sensors, and obtains the boundary conditions for the proposed protocol. Experiment results show that the protocol can be realized in distributed manner, real-time, occupying little hardware resource, so that it is suitable for dynamic acoustic source localization in complicated scene.(2) This paper realized hardware test of the multi-sensor collaboration acoustic source localization protocol. Firstly, the protocol was transplanted into hardware platform to test its precision. Secondly, Energy consumption model was deduced in certain voice event frequency, and tested at hardware platform. Experiment results show that the accuracy can satisfy the need of actual application. But the network energy consumed mainly in surveillance state, which is waste of resources in the energy limited sensor network.