1. LAAS-CNRS, Université de Toulouse, CNRS UPS, Toulouse, France
2. Université de Toulouse, CNRS, ICA, ISAE-SUPAERO, Toulouse, France
3. Department of Information Technology and Human Factors of the AIST, CNRS-AIST JRL (Joint Robotics Laboratory) IRL, Tsukuba, Ibaraki, Japan