Precision assembly with a magnetically levitated wrist

Abstract

In this paper we introduce a new magnetically levitated six-degree-of-freedom fine motion wrist design based on the prototype ″magic wrist″ described in another paper and discuss its use for automated assembly where delicate accommodating motion and precise positioning is required. The new wrist is smaller than the prototype and has several improved features. Parts positioning and assembly strategies are discussed in general, with the classic peg-in hole problem highlighted. Results for insertion of a round peg into a close-fitting chamfered hole using the wrist programmed to emulate a remote center compliance (RCC) are reported. It is found that higher insertion speeds can be maintained with much lower insertion forces and risks of wedging or jamming using this approach.