Received Signal Strength of Electromagnetic Waves Aided Integrated Inertial Navigation System for Underwater Vehicle

Sensory information from an Earth-fixed reference is necessary to guarantee a high localization accuracy of an unmanned underwater vehicle (UUV). However, the implementation of these sensors in an underwater environment is challenging because of signal uncertainties and strong signal attenuation. In this paper, we propose an underwater localization scheme with a sensor fusion of inertial navigation system (INS) and received signal strength of electromagnetic (EM) waves sensors. In the proposed sensor-fusion-based localization scheme, the UUV predicts its location by using INS based on dead-reckoning and corrects the predicted position by Kalman filter using EM waves sensor information when the UUV receives the signals of EM waves sensors in underwater wireless sensor networks. The proposed scheme enables localization with high accuracy and high sampling rate during a long-term task. The results of an experiment performed in a basin environment shows the feasibility of the proposed scheme. The scheme achieved reliable localization accuracy by comparing the pre-measured ground-truth position and long-term navigation. These results show the feasibility of exploiting EM waves attenuation as Earth-fixed reference sensors.