1. Robot System Team, Samsung Research, Seoul, South Korea
2. Department of Mechanical Engineering, University of Caliornia at Berkeley, Berkeley, CA, USA
3. Mechatronics R&D Center, Samsung Electronics, Hwaseong, South Korea
4. Mechanical and Aerospace Engineering Department, Automation and Systems Research Institue (ASRI), Seoul National University, Seoul, South Korea
5. Department of Electrical Engineering and Computer Sciences, University of California at Berkeley, Berkeley, CA, USA