Active omni wheel possessing seamless periphery and omnidirectional vehicle using it

Abstract

Vehicles that are capable of achieving omnidirectional movement will work very efficiently in factories and warehouses. To meet this requirement, various omnidirectional vehicles have been proposed, but the wheel mechanism makes precise movement difficult. The active omni wheel (AOW), which can drive itself in an arbitrary direction at any time, can address this issue, but our previous design had mechanical vibration and acoustic noise due to gaps in the outer circumference of the wheel, and its complicated structure had a large number of parts. To solve these problems, this study developed a new AOW possessing a seamless periphery and simple structure. By using barrel-shaped friction-driven outer rollers arranged alternately on the left and right sides of the wheel, gaps between the outer rollers are eliminated and a smooth periphery is realized. Additionally, the power transmission paths were simplified to reduce the number of parts. This paper explains the AOW structure and then presents analyses of structural conditions and kinematics of the AOW. A two-wheel-drive omnidirectional vehicle using the AOW was built and kinematically analyzed. Finally, experiments using the developed AOW and vehicle were conducted and their effectiveness was verified.