Localization Of Mobile Submerged Sensor Using Cayley-Menger determinant and PSO Algorithm

Abstract

Underwater wireless sensor Networks(UWSNs) are usually deployed over a large sea area and the nodes are usually floating, due to their special environment. This results in a lower beacon node distribution density, a long time for localization, and more energy consumption. Currently most of the localization algorithm in this field do not pay enough consideration on the submerged mobile nodes/sensors. This paper investigates the problem of localizing submerged mobile sensors in a random direction having water current and provides a new mechanism to determine the coordinates of those sensors using only one buoy. In underwater wireless sensor networks (UWSN), the precise coordinate of the sensors that actuate or collect data is vital, as data without the knowledge of its actual origin has limited value. In this study, the method of determining the underwater distances between beacon and sensor nodes has been presented using combined radio and acoustic signals, which has better immunity from multipath fading. Cayley-Menger determinant is used to determine the coordinates of the beacon nodes. The velocity of this beacon nodes is determined using Particle swarm optimization. Finally here the unknown mobile nodes position is determined and updated using the velocities of beacon node/sensors and unknown mobile nodes which have found using PSO algorithm. Simulation results validate the proposed mathematical models by computing coordinates of mobile nodes with negligible errors.