200 Int. J. Mechatronics and Automation, Vol. 4, No. 3, 2014
Copyright © 2014 Inderscience Enterprises Ltd.
Developing adaptable joint admittance control in a
virtual robotic testbed
Eric Guiffo Kaigom* and Jürgen Roßmann
Institute for Man-Machine Interaction,
RWTH-Aachen University,
Ahornstrasse 55, Aachen, Germany
E-mail: kaigom@mmi.rwth-aachen.de
E-mail: rossmann@mmi.rwth-aachen.de
*Corresponding author
Abstract: Over the past years, eRobotics has been proving itself to be a flexible and efficient
approach to tackle highly complex issues in research and application areas of robotics and
automation, including planetary exploration, orbital servicing, sustainable forest management and
industrial manufacturing. One of the main objectives of eRobotics is to bring robotics know-how
into the fields of virtual reality and simulation on the basis of a holistic simulation approach that
swiftly adapts to new demands and lays the foundation for the development of new technologies.
Following this line of ideas, we introduce in this paper a novel systematical and highly modular
approach to endow an open-chain robot manipulator with adaptable joint admittance control on a
robot simulator. A three-stage admittance, position and torque control is developed to provide a
desired joint admittance when external torques are sensed. The joint admittance is adapted by
inferring the human intension to accelerate and decelerate during interaction in an intuitive and
simple fashion. Experiments carried out on a physical 7 DoF KUKA LWR 4+ reveal that the
proposed approach substantially reduces the robot resistance felt by the operator, therefore
enhancing considerably the ease of manipulation.
Keywords: eRobotics; simulation; virtual testbed; robotics; admittance control.
Reference to this paper should be made as follows: Kaigom, E.G., and Roßmann, J. (2014)
‘Developing adaptable joint admittance control in a virtual robotic testbed’, Int. J. Mechatronics
and Automation, Vol. 4, No. 3, pp.200–211.
Biographical notes: Eric Guiffo Kaigom studied Electrical Engineering at the RWTH Aachen
University in Germany. Since 2010, he has been working as a Research Scientist towards his
PhD at the Institute for Man-Machine Interaction at RWTH Aachen University, Germany. His
research interests include: space-, industrial and human-centred robotics, as well as system
simulation techniques.
Jürgen Roßmann studied Electrical Engineering at the Universities of Dortmund and Bochum,
Germany. After his studies, he worked as Researcher and Team Leader at the Institute of
Robotics Research (IRF) in Dortmund. He received his Doctorate in 1993 and was appointed
Visiting Assistant Professor for Robotics and Computer Graphics at the University of Southern
California in 1998. He received his Habilitation degree in 2002 from the University of Dortmund
and Managing Director of EFR-Systems GmbH in Dortmund from 2005 to 2006. Since 2006, he
has been the Director of the Institute for Man-Machine Interaction and Full Professor at the
RWTH Aachen University in Aachen, Germany. His research interests are projective virtual
reality, multi-agent control and supervision, multi-sensor integration, system simulation and
optimisation techniques, computer vision, real-time visualisation and man-machine interaction.
This paper is a revised and expanded version of a paper entitled ‘A new eRobotics approach:
simulation of adaptable joint admittance control’ presented at the Mechatronics and Automation
(ICMA), 2013 IEEE International Conference on, Takamatsu, 4–7 August 2013.
1 Introduction
3D simulation technology is widely used in manufacturing
today. Particularly in robot-assisted manufacturing, it is
usually the method of choice to quickly pre-configure a
work cell or to plan tasks. It has been adopted as a strategic
approach to improve production processes by identifying
inefficiencies and predicting the side effects of making
changes (Holst, 2001). Nowadays, simulation-driven
engineering is tightly incorporated in product lifecycle
management and robotised automation in enterprises to
substantially increase throughput, maximise benefits and
stay competitive (Meike and Ribickis, 2011; Johari et al.,
2007).