Displacement analysis of under-constrained flexible-shaft driven parallel manipulator

In this paper the displacement analysis of an under-constrained parallel robot supported by flexible shafts is addressed. The problem consists of identifying the equilibrium poses of a moving platform when the shaft lengths are changed. Similar to under-constrained cable-driven parallel robots, the moving platform preserves some freedoms once shaft lengths are fixed. Thus, kinematics and statics must be taken into account simultaneously. However in contrast to cables, shafts may also impose torsional resistance on the moving platform which is considered in this study. To investigate the effect of this torsional resistance the pose of the moving platform with respect to the changes of length of shafts is investigated and compared to the pose of moving platform driven by cables.