Kinematic analysis and design of a robotic fish using flapping and flexional pectoral fins for propulsion

Compared with Autonomous Underwater Vehicle driven by traditional screw propellers, robotic fish is characterized by some desired features as high maneuverability and low noise. The research on bionic robotic fish which is propelled by paired pectoral fins has been gradually becoming hotspot in the field of biomimetics and robotics. Based on the research of cownose ray, the profile curve of pectoral fins for the kinematic analysis is established in this paper. We present that the dynamic foil deformation is composed of spanwise flapping and chordwise flexion. A novel bionic fish, Cownose Ray V, with multi-propulsion sources used in pectoral fins is designed, including the mechanical structure and the electronic control system. A towing platform is developed in order to test the propulsion performance of Cownose Ray V. According to the experimental results, the deformation and motion of pectoral fins obtained from Cownose Ray V imitate that of its natural sample to a great extent, which indicates that it can reach the desired propulsion performance.