Precision assembly with a magnetically levitated wrist

A magnetically levitated six-degree-of-freedom fine motion wrist design based on the prototype magic wrist described by R.H. Hollis et al. (1991) is introduced. Its use for automated assembly, where delicate accommodating motion and precise positioning is required, is discussed. The new wrist is smaller than the prototypes and has several improved features. Parts positioning and assembly strategies are discussed in general, with emphasis on the classic peg-in-hole problem. Results from insertion of a round peg into a close-fitting chamfered hole using the wrist programmed to emulate a remote center compliance are reported. It is found that higher insertion speeds can be maintained with much lower insertion forces and risks of wedging or jamming