Modeling the dynamics of biomimetic underwater robot fish

In this paper we propose the model for undulatory locomotion in the developed biomimetic underwater robot fish. The expressions for the momentum and hydrodynamic force on the swimming robot fish´s body are based on large-amplitude elongated body theory and inviscid hydrodynamics, and these are coupled to rigid-body dynamics to derive the kinematic and dynamic equation of the swimming robot fish. Through solving ordinary differential equation, propulsive parameters including swimming velocity, thrust, side force and efficiency can be obtained. For improving the swimming performances, influences of kinetic parameters of body curve and wake structure on these indexes are discussed and we also present the optimal body curve´s parameters and the Strouhal number