Spiraling Motion of a Gliding Robotic Dolphin Based on the 3-D Dynamic Model

This paper proposes a complete three-dimensional (3-D) dynamic model of a gliding robotic dolphin with full consideration of both 3-D gliding motion and flapping motion. The gliding robotic dolphin can not only implement an efficient dolphin-like swimming, but also has long endurance due to the buoyancy-driven system. Firstly, the mechanical structure including dolphin-like swimming part and gliding part of the robot is offered. More importantly, derivation processes of the kinematic analysis, net buoyancy analysis, hydrodynamic analysis, and multi-link dynamic modeling are discussed in detail to provide theoretical support. Furthermore, this paper presents some comparison of the spiraling movements based on these two different swimming motions, and gives the corresponding analyses according to the simulation results. Finally, through comparing results of the aquatic experiments and the simulation, we verify the complete dynamic model, and analyze the yaw angle and diving depth.