1. Chair of Robotics, Artificial Intelligence and Real-Time Systems, School of Computation, Information and Technology, Technical University of Munich, Boltzmannstrasse 3, 85748 Munich, Germany.
2. Machine Intelligence Lab, Department Engineering, University of Technology Nuremberg, Ulmenstrasse 52i, 90443 Nuremberg, Germany.
3. School of Computer Science and Engineering, Sun Yat-sen University, 510330 Guangzhou, China.
4. Pazhou Lab, 510335 Guangzhou, China.