Holonomic under-actuation of parallel robots with topological reconfiguration

Holonomically under-actuated parallel robots are explored in this paper. This concept relies on the ability of the robot to topologically reconfigure itself into various topologies during actuation. The full mobility of the moving platform is realized by a series of changeable over-constrained (lower mobility) systems, via what are called actuation sequences. The design, motion planning, and kinetostatics of this type of parallel robots are presented here. The proposed approach can be used to under-actuate a parallel robot with any number of actuators with any general joint arrangements in the limbs, as long as it meets the minimum specified architecture requirements. Additionally, based on the proposed concept, a design for a wing morphing application is introduced. Furthermore, the concept is validated using a prototype of the holonomically under-actuated morphing wing.