1. Department of Mechanical EngineeringThe University of SheffieldSheffieldS1 3JDUK
2. State Key Laboratory of Mechanical TransmissionChongqing UniversityPeople's Republic of China
3. School of Engineering and Computing SciencesDurham UniversityDurhamDH1 3LEUK
4. Design UnitUniversity of NewcastleNewcastleNE1 7RUUK