[1] Northwestern Polytech Univ, Coll Aeronaut, Xian 710072, Peoples R China
[2] Chinese Acad Sci, Inst Automat, Natl Lab Pattern Recognit, Beijing 100190, Peoples R China
[3] Univ Chinese Acad Sci, Sch Artificial Intelligence, Beijing 100190, Peoples R China
[4] Aerosp Engn Univ, Sch Aerosp Informat, Beijing 101416, Peoples R China