Stabilization based design and experimental research of a fish robot

To reduce the yawing, rolling and pitching of the fish robot and to improve the efficiency of tail fin propulsion, the strength environment of the tail fin thruster was analyzed, the fish robot´s shape is optimized under a novel design principle, which was abbreviated as SPC (stability first, propulsion second, control third), of bionic fish robot, the result was analyzed by computer fluid dynamics simulation using the lift-drag ratio as the key parameter. The experiments of three fish robots of different scales were done. The biggest one, which was 2m in length, reached the maximal speed of 1.5m/s at the frequency of 1.6Hz. And the yawing of all three fish robots were below 5°. The experiments have shown that owing to the improvement of the stabilization the velocity and propulsion efficiency were also improved, and the Strouhal number got into the best region of 0.2-0.3.