An Underwater Robotic Gripper with Embedded Force/Torque Wrist Sensor

Abstract

In this paper, a three-finger underwater gripper with force/torque sensor integrated in the wrist interface is presented. The actuation is based on electric servo motors and cable transmission. The gripper is characterized by 8 Degrees of Freedom (DOFs) actuated by only three motors. The coupling among the DOFs of the fingers is implemented by means of multiple pulleys connected to the motor output shaft. The solutions adopted to make the system at the same time simple enough and suitable for marine applications are discussed and analyzed along with the integration of the sensors needed for handling complex manipulation and cooperation tasks. The effectiveness of the device is tested in a pool where the gripper is part of a complex robotic system composed of an Autonomous Underwater Vehicle (AUV) and a dexterous 7-DOFs arm. The goal of the benchmark experiments is the autonomous search of a known object and its recovery and transportation.