Dynamic Analysis of Flexible Bionic Pectoral Fin of Labriform Fish

Labriform mode is an important maneuvering locomotion mode which is largely applied to teleost fish. It takes the pectoral fin as the main maneuvering surface, accomplishing a variety of maneuvering locomotion such as hovering, forward-swimming, backward-swimming, braking and turning. These maneuvering performances with high-efficiency and flexibility are absent in the conventional underwater vehicle. Therefore, based on the pectoral fin structure and neuromuscular control mechanism, this paper designed a new flexible bionic pectoral fin and built the mathematical model of swing motion of pectoral fin rays as well as the dynamics model of bionic pectoral fin. Then, Simulink was utilized to simulate the dynamic performance. According to the result, this bionic pectoral fin has the excellent dynamic performance and can actualize locomotion morphology of real pectoral fin. In addition, the dorsal–ventral swing motion of middle rays of bionic pectoral fin was taken as under-actuated motion to reduce the quantity of control variables, which provides basis for making of the new bionic pectoral fin with more compact and simple structure.