Frequency‐detected acoustic ranging solutions in wireless sensor networks: an experimental study

Abstract

AbstractRanging is a basic distance estimation for many range‐based localization approaches, which are important to wireless sensor networks (WSNs) applications at many levels. In this paper, we propose a simple frequency‐detected based time difference of arrival (FD‐TDoA), which can be implemented by detecting acoustic frequency to compute the time of flight in air. Furthermore, we put forward a new acoustic ranging solution named time of arrival (TOA)2, which can be applied to WSNs with asynchronous nodes. Unlike other published works, the design of TOA2 uses a bidirectional acoustic signal exchange between a pair of communication nodes. This technique is significantly simple and effective. The latency between the time at which the Mica2 is commanded to emit an acoustic pulse and the earliest possible time that can be detected anywhere, is considered in our solutions. The error of these ranging solutions, the correction expressions by fitted lines and the sensitivity on hardware are analyzed by a large number of experiments based on a resource‐constrained Mica2 hardware platform. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.