1. Professor, School of Electronic and Information Engineering, Hebei Univ. of Technology, Tianjin 300401, China; Professor, ITS Research Center, Wuhan Univ. of Technology, Wuhan 430063, China (corresponding author).
2. Master Student, School of Electronic and Information Engineering, Hebei Univ. of Technology, Tianjin 300401, China.
3. Master Student, ITS Research Center, Wuhan Univ. of Technology, Wuhan 430063, China.