1. Digital Manufacturing Research Center, AIST, Tsukuba, 305-8564, Japan
2. College of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao 266510, P. R. China
3. Department of Mechanical Engineering and Intelligent Systems, University of Electro-Communications, Chofu, Tokyo, 182-8585, Japan
4. Institute of Mechanical Systems Engineering, AIST, Tsukuba, 305-8564, Japan