Autonomous Mission with a Mobile Manipulator—A Solution to the MBZIRC

Abstract

This work presents the system and approach we employed to tackle the second challenge of the Mohamed Bin Zayed International Robotics Challenge (MBZIRC) (See http://www.mbzirc.com/challenge ). The goal of this challenge is to find a tool panel on a field, pick an appropriate wrench from the panel, and operate a valve stem therewith. For this purpose we use a task-oriented field robot, based on Clearpath Husky with a customized series elastic arm, that can be deployed for versatile purposes. However, to be competitive in a robotic challenge, further specialization and improvements are necessary to achieve a certain task faster and more reliably. A high emphasis is put on designing a system that can operate fully autonomously and independently respond if a subtask was not executed successfully. Moreover, the operator can easily monitor the system through a graphical user interface and, if desired, interact with the robot. We present our algorithms to explore the field, detect the panel, and navigate to it. Furthermore, we use a support vector machine based object detection method to locate the valve stem and wrenches on the panel for visual servoing. Finally, we show the advantages of a force controllable manipulator to handle the valve stem with a tool. This system demonstrated its applicability when fulfilling the entire task fully autonomously during both trials of the Grand Challenge of the MBZIRC 2017.