[1] Xidian Univ, Sch Electromech Engn, Xian 710071, Peoples R China
[2] Macau Univ Sci & Technol, Inst Syst Engn, Taipa, Macau, Peoples R China
[3] Univ Cagliari, Dept Elect & Elect Engn, I-09123 Cagliari, Italy
[4] Univ Toulon & Var, Aix Marseille Univ, CNRS, ENSAM,LSIS, Marseille, France