A distributed particle swarm optimization based localization scheme in underground tunnels

One of the main concerns in underground working tunnels is ensuring the safety of the workers and their equipment. Being aware of the real-time position of personal in such hash environments is challenging and requires a sophisticated localization system. Due to extreme multipath and non-line of sight (NLOS) conditions, wireless signals in underground narrow-vein tunnels suffer multiple kinds of distortions. Unreliable measurements of location metrics such as received signal strengths (RSS), result in deterioration of localization performance. In this paper, a radio frequency time of flight (RF-TOF) range engine embedded in JN5148 microcontroller is validated as an alternative range method in such scenarios. To reduce the communication cost and time delay of localization in such chain type wireless network, a distributed particle swarm optimization (PSO) based localization algorithm is proposed and implemented on the blind node. Without overhead hardware needed, an accurate and low cost localization system can be achieved. Experimental results verify the proposed scheme.