Dynamic analysis and control synthesis of a link-based dolphin-like robot capable of three-dimensional movements

This paper presents a three-dimensional (3-D) dynamic model for a self-propelled, multilink dolphin-like robot to predict the dynamic behaviors of the bio-inspired artificial dolphin system within the framework of multibody dynamics. The propulsive structure mimicking dorsoventral motion includes a multilink tail and a flexibly oscillating fluke moving in coordination, as well as a pair of mechanical flippers performing flapping movements. This configuration can practically be simplified as an open-chain, tree-like multibody with a mobile base. The Schiehlen method is then employed to formulate the equations of motion based on the well-integrated kinematic and dynamic analyses of propulsive elements. Several locomotor behaviors, via coordinated control of the propulsors, can be principally replicated and numerically evaluated. Comparative results between simulations and experiments on forward swimming and combined motions are shown to demonstrate the effectiveness of the created model and locomotion control methods for dolphin-like swimming.