1. Institute of Automatic Control and Control Systems Technology , Johannes Kepler University Linz , Linz , Austria
2. Chair of Systems Theory and Control Engineering , Saarland University , Saarbrücken , Germany
3. Institute of Measurement, Control and Microtechnology , Ulm University , Ulm , Germany
4. Institute of Automation and Control Engineering , UMIT TIROL – Private University for Health Sciences and Health Technology , Hall in Tirol , Austria