Kinematic modeling of a bio-inspired robotic fish

This paper proposes a kinematic modeling method for a bio-inspired robotic fish based on single joint. Lagrangian function of freely swimming robotic fish is built based on a simplified geometric model. In order to build the kinematic model, the fluid force acting on the robotic fish is divided into three parts: the pressure on links, the approach stream pressure and the frictional force. By solving Lagrange´s equation of the second kind and the fluid force, the movement of robotic fish is obtained. The robotic fish´s motion, such as propelling and turning are simulated, and experiments are taken to verify the model.