Development of a mobile manipulator for nuclear plant disaster, HELIOS X (Mechanical design and basic experiments)

Abstract

In places such as nuclear power plant disaster area, which it is difficult for human workers to enter, robots are required to scout those places instead of human workers. In this paper, we present a mobile manipulator HELIOS X for a nuclear plant decommissioning task. Firstly, we address demands and specifications for the robot, considering the mission of reconnaissance. Then we outline the system of the robot, mainly focusing on the following mechanism:“Crank Wheel”, “ Main Arm ”,“ Sphere Link Wrist ”,“ Camera Arm ”,“ Control System ”and“ System architecture ”. Especially, we installed 3 degree of freedom“ Camera Arm ”on the“ Main Arm ”, in order to improve functionality of remote control system. This enables the operator to monitor both the gripper and its overall view of the robot.“ Camera Arm ” helps the operator to recognize the distance from an object to the gripper, because the operator can interactively move the viewpoint of the camera, and monitor from another camera angle without changing the gripper’s position. We confirmed the basic functionality of mobile base,“ Main Arm ”and“ Camera Arm ”through hardware experiments. We also demonstrated that HELIOS X could pass through the pull-to-open door with a substantial closing force when the operator watched camera view only.