Design And Research On A Biomimetic Robotic Stingray With An Undulatory Pectoral Fin

With the development of marine economy and the increasing importance of marine rights and interests' protection, the requirements for marine survey and salvage equipment are increasing. Compared with traditional underwater robots propelled by propellers, biomimetic underwater robots inspired by fishes have higher efficiency, flexibility and stability. Among fish swimming modes, pectoral fin undulatory propulsion mode presents some obvious advantages with greater maneuverability, controllability and stability than caudal fin propulsion mode. In the current study, a robotic fish inspired was designed and developed by imitating the morphology and swimming mode of stingray. It will provide a new kind of underwater equipment platform for the development of marine resources and diving salvage.In order to provide biological basis and biomimetic ideas for design of the robotic stingray, characteristics in morphology, physiology and locomotion of stingray were studied. Based on biological characteristics of stingray and several assumptions, a simplified physical model of stingray was established. Then, kinematic model of the undulatory pectoral fin was built through characteristic parameter identification, results were analyzed by simulation. By reference to Resistive Force Theory, hydrodynamic model of the pectoral fin was established.The bio-inspired robotic fish was developed by imitating the morphology, pectoral fin skeleton structure and muscular structure of stingray. The shape of the fish robot was designed by mimicking the flat streamline body of stingray and the robot was composed of flexible undulatory pectoral fin, diving adjustment mechanism, battery and control system. Based on locomotion mechanism of stingray, the swimming strategy of robotic fish was analyzed.The experiments were conducted to examine the propulsion performance of the developed robotic stingray. As we varied the frequency, amplitude, wave number and undulatory mode of the biomimetic pectoral fin, the surge force, sway force and heave force generated by the robotic fish was measured. Effects of these undulatory parameters on the propulsion performance were analyzed. In order to study the swimming performance of the robot, experiments were conducted. Results indicate that the robotic fish can swim like stingray, the movement is flexible, and the maximum swimming speed is 5.35cm/s(0.22BL/s), the minimum turning circle is 12 cm.