単球によるACROBAT全方向移動機構の運動解析と試作

抄録

In this paper, we present motion analysis and prototype design of a new omni-directional wheel mechanism "ACROBAT-S". The authors group has proposed a special kind of transmission with a dual-ball configuration for transmit drive powers to wheel shaft and steering shaft of an active-caster mechanism (ACROBAT). In the transmission design, two balls are required where one ball is used for combining the two motor powers to rotate the ball in 2D way while another ball is for distributing the combined power to the wheel and steering. The transmission design enables an omnidirectional robot with three active casters for controls 3D motion of a robot by three motors with no redundancy. To reduce the number of friction drive between balls and rollers in the first design, a new type of ACROBAT with a single ball transmission (ACROBAT-S) is proposed in this paper. The proposed new design with single ball configuration contributes to reduce the number of friction drives between balls and rollers for enhancing an energy efficiency and accuracy of robot movement. To design a proposed mechanism, a kinematics of a ball, a roller and active-caster motions are analyzed to derive a mechanical condition for the prototype design. In this paper, we design and build a prototype of a single wheel and conduct experiments. From the results, it was confirmed that an expected motion can be realized.