Kinematics analysis of n-4r reconfigurable parallel mechanisms

In this paper, a family of n-4R reconfigurable parallel mechanisms (RPMs) capable of geometrical reconfiguration are presented, and the effect of the limb number n on the DOF, workspace and accuracy is investigated. An amazing fact is that the reconfiguration results in these multiple candidate configurations with similar kinematic performances and even the same DOF characteristic, which is maybe helpful for robustness and hyper-redundant design of mechanical devices. Meanwhile, each configuration has its own associated workspace and accuracy capabilities, although the variance is not obvious. This work will provide some guidance in selecting the appropriate configuration or further optimization.