Abstract
We present a general method for worst-case limit kinematic tolerance analysis that covers fixed and changing contact mechanisms with parametric or geometric part tolerances. The method computes the variation in the kinematic function of mechanisms resulting from manufacturing variation in the shapes and configurations of their parts. We develop a new model of kinematic variation, called kinematic tolerance space, that generalizes the configuration space representation of nominal kinematics function. Kinematic tolerance space captures quantitative and qualitative variations in kinematic function due to variations in part shape and part configuration. We derive topological properties of kinematic tolerance space that express the relationship between the nominal kinematics of mechanisms and their kinematic variations. Using these properties, we develop a practical kinematic tolerance space computation algorithm for planar pairs with two degrees of freedom and for assemblies of such pairs with independent part tolerances.