Design and analysis of controlling the robotic fish

Recently fish robots are widely used in various applications such as ocean investigations, military operations and marine environment protection. It requires high performance autonomous underwater vehicles especially for propulsion and great benefits with flexible manoeuvrability. In this paper focused on the fish propulsion mechanism, robotic fish overall design and dynamic model of robotic fish propelled by the pectoral fins and flexible tail. The tail part of the fish is attached to the active body segments which are connected in series through rotational springs and the hydrodynamic force will act on each segment. It can navigate efficiently over a given distance with a good balance of speed and manoeuvrability. Different mathematical propulsive waveforms are combined with an inverse kinematics-based approach for generating fish body motions. A prototype is built and is tested. The experiment results demonstrate that the kinematics of the robot fish can be predicted effectively. The above results indicate the proposed model is suitable for estimation of the behaviour, thrust and swimming speed of the fish robot.