1 School of Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China.
2 School of Mechanical and Mechatronic Engineering, Faculty of Engineering and IT, University of Technology, Sydney, P.O. Box 123, Broadway, NSW 2007, Australia.
3 School of Mechanical and Mechatronic Engineering, The University of Technology Sydney, Sydney, NSW 2007, Australia.