Sensing the neighboring robot by the artificial lateral line of a bio-inspired robotic fish

Fish possesses a unique sensory organ called the lateral line. The lateral line provides fish with flow-related information. It is accepted that fish can use the lateral line to sense states of its neighbours in schooling behaviors. In this study, we investigate how a focal robotic fish senses the states of its swimming neighbour by using its onboard artificial lateral line system for the first time. Dye flow visualization is used to characterize the large-scale structures of the wake behind a swimming robotic fish. In the experiment, the Reverse Karman Vortex Street generated by the anterior robotic fish was sensed by the artificial lateral line of the focal robot. The results show that the robot´s artificial lateral line can detect the beating frequency of its neighbouring robot and the distance between the robots. It is promising that artificial lateral line sensing could become one of the most popular close interaction methods for a group of underwater robots in the near future.