Static attitude control for underwater robots using multiple ballast tanks

摘要

A new dynamic control scheme that uses the center of gravity is proposed to control the attitude of an underwater robot. Instead of using thrusters, ballast tanks are used for the static attitude control to avoid generating disturbances around the robot and to lower the power consumption. Five attitude ballast tanks are used to control the roll and pitch of the robot via the translocation of water. Using the dynamic center of gravity, the attitude can be maintained and controlled at a desired angle. The dynamics of the robot are derived using Lagrangian equations. By using the dynamic equations to find the optimal gains of the Proportional Derivative (PD) controller, this robot has been designed to have a fast attitude control capability with low power consumption. Through real experiments, it is demonstrated that the attitude control is efficient and accurate by adjusting the center of gravity. It is also verified that this system has outstanding efficiency in power consumption compared to conventional propeller systems. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.