ABSTRACT

We present a general method for worst-case limit kine­ matic tolerance analysis: computing the range of varia­ tion in the kinematic function of a mechanism from its part tolerance specifications. The method covers fixed and multiple contact mechanisms with parametric or geometric part tolerances. We develop a new model of kinematic variation, called kinematic tolerance space, that generalizes the configuration space representation of nominal kinematic function. Kinematic tolerance space captures quantitative and qualitative variations in kinematic function due to variations in part shape and part configuration. We derive 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 prac­ tical kinematic tolerance space computation algorithm for planar pairs with two degrees of freedom.