Effect of body stiffness on the swimming performance of a robotic fish

Previous biological experiments show that the fish has a super swimming performance when the driven frequency is closed to the natural frequency. Inspired by that, a biomimetic fish based on continuous compliant visco-elastic body is presented, and the body dynamics deduced from the Bernoulli-Euller beam equation is also proposed. More important, we provide a proposition to determine the body stiffness and the driven frequency, namely, a robotic fish with different body stiffness E1I1, E2I2 obtain a better swimming performance at the corresponding driven frequency w(1), w(2), then there exist this relationship: E2I2 : E1I1 =w(2)(2) : w(1)(2). Further, it is proved by the experiments of robotic fishes with different body stiffness. The experiment results show that the swimming performance of robotic fish is largely dependent on the body stiffness and the driven frequency.