A new active-caster drive system with a dual-ball transmission for omnidirectional mobile robots. - Masayoshi Wada; Yusuke Inoue; Takahiro Hirama (IROS, 2012)

Traction analysis for Active-caster omnidirectional Robotic drive with a Ball Transmission (ACROBAT). - Masayoshi Wada; Takahiro Hirama; Yusuke Inoue (AIM, 2013)

Design of omnidirectional mobile robots with ACROBAT wheel mechanisms. - Yusuke Inoue; Takahiro Hirama; Masayoshi Wada (IROS, 2013)