1. Mechanical Engineering Group, School of Engineering, University of Kent, Canterbury CT2 7NT, UK
2. School of Mechanical Engineering Sciences, University of Surrey, Guildford GU2 7XH, UK
3. School of Engineering, Technology and Design, Canterbury Christ Church University, Canterbury CT1 1QU, UK
4. Intelligent Interactions Group, School of Engineering, University of Kent, Canterbury CT2 7NT, UK