Landing control for a jumping machine. - Eiji Nakano; Hiroki Okubo; Hiroshi Kimura (Adv. Robotics, 1992)

Motion control of leg-wheel robot for an unexplored outdoor environment. - Yu-Jie Dai; Eiji Nakano; Takayuki Takahashi; Hiroki Okubo (IROS, 1996)

Design of a jumping machine using self-energizing spring. - Hiroki Okubo; Eiji Nakano; Minoru Handa (IROS, 1996)

Robot therapy as for recreation for elderly people with dementia - Game recreation using a pet-type robot -. - Toshimitsu Hamada; Hiroki Okubo; Kazuya Inoue; Joji Maruyama; Hisashi Onari; Yoshihito Kagawa; Tomomi Hashimoto (RO-MAN, 2008)