Practical modeling and system identification of R/C servo motors. - Takashi Wada 002; Masato Ishikawa; Ryouhei Kitayoshi; Ichiro Maruta; Toshiharu Sugie (CCA/ISIC, 2009)

The surface walker: a hemispherical mobile robot with rolling contact constraints. - Masato Ishikawa; Yoshinori Kobayashi; Ryouhei Kitayoshi; Toshiharu Sugie (IROS, 2009)

Volvot : A spherical mobile robot with eccentric twin rotors. - Masato Ishikawa; Ryouhei Kitayoshi; Toshiharu Sugie (ROBIO, 2011)