1. College of Automation and Electronic Engineering, Qingdao University of Science and Technology, Qingdao, China
2. College of Sino-German Institute Science and Technology, Qingdao University of Science and Technology, Qingdao, China
3. School of Information Science and Technology, Qingdao University of Science and Technology, Qingdao, China
4. College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao, China