Control of Mobile Manipulator Using a Virtual Impedance Wall

Tomohito Takubo, Hirohiko Arai and Kazuo Tanie

Proceedings of 2002 IEEE International Conference on Robotics and Automation (ICRA2002), pp.3571-3576, Washington DC, USA, May 2002.


In this paper, we present a method controlling mobile manipulators for assist systems.The mobile manipulator should provide good manipulability and stability in any time. Most of mobile assist systems have a heavy mobile base for stability. Therefore, the movement of the mobile base causes high energy consumption. Furthermore, the slow dynamics of the mobile base deteriorates the system reaction. Thus, we propose an approach for motion control for mobile manipulator to remove unnecessary movement of the mobile base. In our proposed scheme, the mobile base dose not move until the manipulator tip position or the mobile base goes over user-defined area which compensate the manipulability or the stability. If the manipulator tip position or the mobile base reaches boundary of the preferred operating area, the mobile base start to move for recovering the manipulability and stability. The boundary are consisted of a virtual spring and a dumper by impedance control. To verify the validity of the proposed scheme, we have carried out experiments employing a graphic simulator and a real robot. The experimental result shows the effectiveness of the proposed scheme.


Human-robot cooperation, Cooperative manipulation, Impedance control, Mobile Manipulator, Virtual impedance wall