The Transmissivity and Manipulability of Spatial Mechanisms

A method of evaluating the transmission performance for spatial mechanisms is developed using the reciprocity of screws. The actual transmission performance of a spatial mechanism should be composed of two parts: the ability of the output that can be effectively generated by the mechanism is called the “transmissivity,” and the ability of the input that can be effectively absorbed into the rest part of the mechanism is called the “manipulability.” A more generalized index for the overall transmission performance of spatial mechanisms is then defined and illustrated by some spatial four-link mechanisms.