Abstract
As described in this paper, we derive the dynamics of closed-loop mechanical systems for underwater applications and present a numerical simulation of an underwater system. The dynamics model derived here is useful for analysis, control, and optimization for underwater parallel mechanisms and underwater object manipulation by multiple arms or fingers. As a first step, a two-dimensional underwater manipulator system with a stationary vehicle is modeled in this work. The dynamics model is coupled with hydrodynamic effects. Using the derived model, we conduct underwater object manipulation based on a force control method for use with underwater manipulators to prevent their contact points from slipping on an object surface. Moreover, we discuss the usefulness of the model and the dynamics of a free-floating vehicle-manipulator system with a closed-loop structure.
