A bio-inspired electrocommunication system for small underwater robots

Abstract

Weakly electric fishes (Gymnotid and Mormyrid) use an electric field to communicate efficiently (termed electrocommunication) in the turbid waters of confined spaces where other communication modalities fail. Inspired by this biological phenomenon, we design an artificial electrocommunication system for small underwater robots and explore the capabilities of such an underwater robotic communication system. An analytical model for electrocommunication is derived to predict the effect of the key parameters such as electrode distance and emitter current of the system on the communication performance. According to this model, a low-dissipation, and small-sized electrocommunication system is proposed and integrated into a small robotic fish. We characterize the communication performance of the robot in still water, flowing water, water with obstacles and natural water conditions. The results show that underwater robots are able to communicate electrically at a speed of around 1 k baud within about 3 m with a low power consumption (less than 1 W). In addition, we demonstrate that two leader-follower robots successfully achieve motion synchronization through electrocommunication in the three-dimensional underwater space, indicating that this bio-inspired electrocommunication system is a promising setup for the interaction of small underwater robots.

An Electrocommunication System Using FSK Modulation and Deep Learning Based Demodulation for Underwater Robots

“…In China, Northwestern Polytechnical University designed a DSP-based electrocommunication device, which was an important practical achievement [11]. Recently, an artificial electrocommunication system based on 2ASK modulation was developed for and successfully implemented in small underwater robots [12], [13]. Thus, it is a promising setup for communication within small underwater robots.…”

“…Thus, it is a promising setup for communication within small underwater robots. However, the communication distance of the electrocommunication system in [12], [14] is still very short for underwater robots, which limits its application in the practice environment. One possible solution to increase the communication distance is simply improving the transmitting power of the system.…”

Electrocommunication for weakly electric fish

“…They generate a stable, relatively high-frequency, weak electric field and transdermically perceive the corresponding feedback by means of many receptors on its skin. Since they have an electric sense that allows underwater navigation, target classification and intraspecific communication, they are privileged animals for bio-inspiring man-built autonomous systems [14,18,19,21,24,29,39,40]. For electro-communication purposes, in processing sensory information, this system has to separate feedback associated with their own signals from interfering sensations caused by signals from other animals.…”

Three-Dimensional Dynamic Modeling and Motion Analysis for an Active-Tail-Actuated Robotic Fish with Barycentre Regulating Mechanism

“…I N recent years, underwater robots including varieties of underwater remotely operated vehicles (ROV), autonomous underwater vehicles (AUV), and bio-inspired aquatic systems [1] have been developed and shown great potentials in promoting marine resource exploitation [2], [3], marine economy development [4], [5], and marine ecological environment protection [6], [7]. The research topics of underwater robots cover locomotion control and optimization [8], [9], underwater navigation and localization [10], [11], environment perception and object recognition [12], [13], underwater communication [14], [15], etc. In particular, mechanism investigation of dynamic performance of underwater robots is fundamental and critical for the above-mentioned researches.…”