1. Vienna University of Technology, Institute of Mechanics and Mechatronics, Getrieidemarkt 9, 1060 Vienna Austria
2. Technical University of Darmstadt, Institute for Mechatronic Systems, Otto-Berndt Strasse 2, 64287 Darmstadt, Germany
3. Institute of Fundamental Technological Research, Polish Academy of Sciences, ul. Pawińskiego 5B, 02-106 Warsaw, Poland