1. School of Automation, Guangxi University of Science and Technology, Liuzhou 545006, China
2. Guangxi Collaborative Innovation Centre for Earthmoving Machinery, Guangxi University of Science and Technology, Liuzhou 545006, China
3. Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610209, China
4. School of Electronic and Information Engineering, Xi’an Jiaotong University, Xi’an 710049, China