Design and implementation of a novel biomimetic robotic jellyfish

This paper deals with the design, construction, and motion control of a jellyfish-inspired swimming robot that uses jet propulsion for thrust generation. The robotic jellyfish consists of a streamlined head, a cavity shell, four separate drive units with bevel gears, as well as an elastic rubber skin around the drive units. In order to replicate the locomotion of jellyfish including a relaxation phase and a contraction phase, four six-bar linkage mechanisms that are centrally symmetric are adopted as the actuators. A triangular wave control algorithm is then proposed to produce desired control signals with an embedded controller. Through independent and coordinated control of the four drive units, the robotic jellyfish is capable of diverse propulsion and maneuvers like swimming forward, turning, and diving/surfacing. Aquatic experiments are further conducted to verify the proposed design and control methods. As a new type of bio-inspired robots, the robotic jellyfish will serve as an effective platform for underwater reconnaissance and environmental monitoring.