A dynamic approach to high-precision parts mating

The authors present seldom-discussed sources of error in force-guided motions to execute assemblies. Among these sources are noisy F/T (force/torque) readings, the presence of sliding and sticking frictions, and the possibilities of eccentric oblique impacts. They point out how most of these errors might be reduced or eliminated. The authors introduce the notion of straight line motion goals (SLMGs) and show how SLMGs can be considered as the basic building blocks of a dynamic planning strategy. The steps required to carry out peg-in-hole experiments are examined. It is shown how the torque vector can be used to compute the direction in which the peg should be compliantly moved to align the axes of the peg and the hole. The authors present an error-detection-and-recovery algorithm for these experiments and show the dependence of the success rate on the number of error-detection-and-recovery cycles allowed