Planning for Assembly with Robot Hands

Abstract

If an autonomous robot system is to make effective use of a dextrous hand for assembly, it must be able to (1) reason about how objects are intended to fit together and design mating trajectories, (2) derive uncertainty constraints which accommodate perturbations from the nominal trajectories, (3) and determine how objects should be grasped to exert the forces expected during execution. This paper discusses a planning system which exploits the knowledge of symmetry incorporated in a group theory based reasoner to arrive at a nominal assembly plan. The plan is then refined by establishing bounds on the permissible uncertainty and required forces. A final stage plans force mediated interaction by incorporating multiple agents which enforce the wrench closure requirements and uncertainty constraints over the space of possible grasps.