Contact and jamming analysis for three dimensional dual peg-in-hole mechanism (English)

For a three dimensional multiple peg-in-hole mechanism, robot assembly is a complex process. In this paper, the force/moment and jamming analysis of the three dimensional dual peg-in-hole mechanism is presented. To simplify the analysis, only multiple pegs are considered which are round and have the same length. First, 20 contact states of the three dimensional dual-peg are enumerated and geometric conditions are derived. Second, the contact forces are described by the screw theory in three dimensions. The force/moment equations for static equilibrium states of three dimensional dual-peg insertions are derived. Third, the jamming diagrams are obtained. Different peg and hole geometry, and different insertion depth may yield different jamming diagrams. Eleven different types of possible jamming for each jamming diagram have been identified. Based on the analysis, an experiment of a dual peg-in-hole assembly is presented. The results verify that the analysis above is effective. They also show that the assembly process in six degrees of freedom is more complicated than that for planar motion.