An innovative electromechanical underwater telemanipulator-present status and future development

An innovative underwater manipulator arm with electromechanical joints has been developed and tested in the laboratory. This paper describes the main features of the manipulator developed according to this approach, its present development status and the envisioned future development. It is an antropomorphic arm with 6 degrees of freedom plus grip. The joint architecture is based on high performance brushless DC motors, harmonic drive gears, and sensing and closed loop control of the output torque, performed locally to the joint; it includes also a resolver for measuring the output shaft position and speed. Two different operating modes have been successfully demonstrated so far: unilateral master/slave teleoperation and telemanipulation with supervisory control. The implementation of bilateral telemanipulation with reflection of the interaction force on a motorized master arm is foreseen in the next development phase. >