1. Institute for Technical Mechanics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria,
2. Linz Center of Mechatronics GmbH, Altenbergerstr. 69, A-4040 Linz, Austria
3. Institute for Technical Mechanics, Johannes Kepler University Linz, Altenbergerstr. 69, A-4040 Linz, Austria