Force transmission analysis of spherical 5R parallel manipulators

Being as the counterparts of serial robots, parallel manipulators are good at force transmission but not only dexterous manipulation. In this study, a generalized frame-free transmission index is first proposed. Based on the frame-free index, the force transmission performance analysis of spherical 5R parallel manipulators is presented. By giving a specified and significative value, the index can be used to identify a good-transmission workspace (GTW), where the parallel manipulator not only is good at force transmission but also is far away from its singularity. We expect that the proposed index could be applied to the analysis and kinematic optimal design of not only the spherical 5R parallel manipulators but also other fully parallel manipulators.