Modeling of a caudal-fin-driven robotic fish with buoyancy-adjusting system

In this paper, the dynamic model of a self-developed robotic fish propelled by a flexible caudal fin is presented. The robotic fish has a rigid body and a flexible caudal fin. The dynamic model is derived in accordance with the momentum and angular momentum theorem, and the 6 degree-of-freedoms (DOFs) model is built. To get the hydrodynamic parameters, the particle swarm optimization (PSO) method is employed. On this basis, the original 6 DOFs model is decoupled into horizontal and vertical models, whose effectiveness is confirmed by simulation and experiments. In final, experimental results are provided.