Development of Dam Inspection Underwater Robot. - Hiroyasu Hirai; Kazuo Ishii (J. Robotics Netw. Artif. Life, 2019)

Evaluation of Two Rollers Arrangement on a Hemisphere by Kinetic Energy. - Kenji Kimura; Yusuke Abematsu; Hiroyasu Hirai; Kazuo Ishii (J. Robotics Netw. Artif. Life, 2022)

Forward Kinematic of a Sphere Considering Slipping and Motion Analysis in Three Rollers. - Kenji Kimura; Koki Ogata; Hiroyasu Hirai; Takumi Ueda; Kazuo Ishii (J. Robotics Netw. Artif. Life, 2023)