Biomimetic Electric Sense-Based Localization: A Solution for Small Underwater Robots in a Large-Scale Environment

This article presents a novel localization scheme for free-swimming small underwater robots in a large-scale environment. Accurate localization technology has always been a challenge for small underwater robots since the underwater lighting conditions can limit their vision, while the multipath interference issue occurring near a wall plagues the sonars. By contrast, some kinds of fish perceive their positions by sensing the electric field in their environment, giving them the ability to accurately localize in underwater environments. Inspired by the electric sense behavior in fish, this article proposes a large-scale localization scheme based on electric sense for small underwater robots. Our scheme includes an electric sense-based hardware solution and localization methods. Specifically, we first design a hardware solution, including electric emitters placed in an underwater environment and an electric receiver that can be furnished on a small underwater robot. Then, we propose distributed emitter architectures for large-scale localization. Finally, we propose three localization methods to estimate the position and orientation of the robot. We have conducted four types of localization experiments for a small underwater robot, demonstrating the robustness and effectiveness of our proposed electric sense-based scheme. Our study provides a novel solution to the localization of free-swimming underwater robots with a limited payload and also helps provide insights into large-scale underwater localization.