Underwater electric current communication of robotic fish: Design and experimental results

Communication is challenging for underwater robots. This paper presents the first research into developing an underwater electric current communication system and integrating the system into a small robotic fish. It is notable for its potential for a group of underwater robots communicating within a short distance range in conditions where optical and acoustic methods would meet difficulty. The working principle of the electric current communication is explained by a simplified electric dipole model. After that, systematic design of the electric current communication system is proposed for underwater robots. Communication experiments with the robotic fish demonstrate the effectiveness of the developed electric current communication system. The experimental results show that a remote control system can communicate underwater with our robotic fish over a distance of three meters by use of electric current communication.