Re-design of force redundant parallel mechanisms by introducing kinematical redundancy

Force redundant mechanism is adopted to achieve high acceleration. However, utilizing the good velocity control performance of servo motor to achieve a high positional accuracy will arise excessive big internal forces. Therefore, an idea of introducing kinematical redundancy into force redundant parallel mechanism is proposed. In this idea, we do not add kinematical redundancy on the sub arm but introduce internal redundant motion into the top plate. The concept of this research is illustrated by improving a simple force redundant parallel example, and the merits of the improved mechanism are summarized. This theory is applied into modifying the real high speed parallel mechanism NINJA. Its kinematics and static force relationship are derived and compared respectively. The prototype of the new mechanism is proposed.