Design and control of a fish-inspired multimodal swimming robot

Presented in this paper is our effort to create a multifunctional swimming robot, i.e., robotic fish, inspired by the well-integrated, configurable multiple control surfaces existing in real fish. By virtue of the hybrid propulsion capability in the tail plus the caudal fin and the maneuverability in accessory fins, a novel, synthesized propulsion scheme composed of multiple artificial control surfaces is proposed, involving the tail plus the caudal fin, pectoral fins, pelvic fin, and dorsal fin. Multimodal locomotion is then accomplished by manipulation of control surfaces, separately or cooperatively, allowing the robot to maneuver more diversely and agilely. In particular, bio inspired Central Pattern Generators (CPGs) based locomotion control is adopted for online swimming gait generation. Aquatic testing has been carried out to demonstrate the improved maneuverability and stability of the robotic fish underwater as well as the effectiveness of the conceived multi-fin mechatronic design.