Kinematic coupling interchangeability

The deterministic nature of kinematic couplings enables closed-form characterization of interchangeability error, parametrized in terms of the magnitudes of manufacturing tolerances in the interface manufacturing and assembly processes. A process is suggested for calibrating kinematic couplings to reduce the interchangeability error, based on measurement of the contact points and calculation of a transformation matrix between the interface halves. A Monte Carlo analysis is developed and validated for predicting interchangeability of canoe ball kinematic couplings, and repeatability measurements and interchangeability simulation results are presented for kinematic coupling interfaces for the base and wrist of an industrial robot. Total mounting error, defined as the sum of the interchangeability and repeatability errors, appears to be dependent to first order only on the interface repeatability and the error of the interface calibration procedure.