Positioning of Floating Underwater Robot Arm Using Counter Arm and Reaction Wheel.

Abstract

For a small underwater robot floating in water, it is impossible to position the arm precisely only with the arm actuator, because the body is moved by the action of a fluid drag force and an inertial force acting on the arm. In this study, the positioning of the arm using a redundant counter arm and an internal reaction wheel is proposed for suppressing the flow disturbance around the robot. The counter arm, which is located in an axially symmetrical position, is used to cancel the forces acting on the operating arm. The reaction wheel is used to cancel the moment acting on the body. The arm positioning system using these actuators for the floating underwater robot is developed based on the optimal control theory. The performance of this system was confirmed by experimental models. It was shown that the counter arm and the reaction wheel are very effective for the precise positioning of the arm.