Analysis of Electrode Configuration of Underwater Electric Field Sensor on Electric-Field-based Localization for Underwater Robots

This paper addresses the effects of electrode configurations of an underwater electric field sensor (EFS) on the localization of underwater robots when the robots used electric field measurements to estimate their positions. Around an underwater electric landmark that generates a known electric field signature, an underwater robot equipped with an EFS can measure the signature to localize itself by searching for the position that minimizes the difference between the actual measurement and the theoretical calculation that should be measured when the robot is located at the position. The underwater robot’s localization accuracy was analyzed in simulations when the robot was equipped with EFSs with different electrode configurations. In general, the electric field measurement accuracy and the consequent robot localization accuracy were higher when the robot was equipped with the EFS that consists of more electrodes. Depending on the measurement conditions, however, the use EFSs with less electrodes was enough to perform sufficiently accurate localization of the robot. The proposed simulation method would contribute to suggest the optimal electrode configuration of the EFS, and therefore, the robot localization with the electric field measurements would become more energy-efficient with the use of the suggested cheap and small EFS.