Research On Node Localization Based On Dual-Microphone Array

With the development of wireless sensor networks, the research of wireless sensor network localization problem is a hot research topic. Node localization is an important branch of wireless sensor network localization. Node localization provides preconditions for the target location and the localization accuracy of the target node results plays a very important role.Though there are many localization schemes in wireless sensor networks, due to the limitation of the power consumption, cost and hardware conditions, those schemes can't be applied in many scenarios. (1) GPS-based localization schemes is not very ideal due to the interference of indoor and outdoor buildings. (2) TOA and TDOA based traditional node localization scheme is very sensitive to errors, which means small errors may lead to tremendous errors in localization results. (3) In the complex indoor and outdoor environments, the traditional acoustic based node localization scheme is facing great challenges. This paper proposes two node localization algorithms based on dual-microphone. One is the External Event-Driven Based Localization (EDL) scheme. When the acoustic events scans wireless sensor nodes, the node can get the sequence of nodes and a binary sequence. By processing the node sequence. It determines the location of the node and orientation. The scheme has a good fault tolerance, because each node is associated with a lot of sequence. Another localization scheme is Internal Event-Driven Based Localization (IEDL). The concurrence of speaker and dual-microphones on a sensor node enables the realization of sound signal detection and enables a sound signal to be a driven event. It uses range-based scheme to do the localization work. At the same time it brings in the orientation relationship between nodes to iterate more steps to achieve the purpose of precise localization.Through analysis, simulation and experimental evaluations, our proposed IEDL scheme can achieve good positioning accuracy and good robustness and fault tolerance compared with other scheme. In the open and noisy indoor environments, the algorithm still works fine and has a good precision, which fully illustrated practicality and effectiveness of IEDL.