Regrasp planning of three-fingered hand for a polygonal object

This paper addresses the problem of regrasp planning for a polygon with a large number of edges. We propose an approach for computing sequences of finger repositioning that allow the hand to switch from one grasping configuration to another while maintaining force-closure during the entire process. The proposed approach is based on exploring a structure called switching graph. Complete sets of two-fingered force-closure grasps are computed in grasp space. Adjacent sets of force-closure grasps are merged into a connected set which allows finger repositioning by continuous movements of fingers on adjacent polygonal edges. We present an output sensitive algorithm to construct a switching graph from the obtained connected sets. A method for finding the optimal solution of a finger switching is also presented. The proposed approach has been implemented and some preliminary results are presented.