1. Department of Electrical and Computer Engineering, Hellenic Mediterranean University (HMU), Heraklion, Crete, Greece
2. School of Electrical and Computer Engineering, Technical University of Crete, Crete, Greece
3. Mechatronics Research Group, Faculty of Engineering and the Physical Sciences at the University of Southampton, Southampton, U.K.
4. TSL Technology Ltd., Ropley, U.K.