A new method to determine the base inertial parameters of planar mechanisms

Abstract

This paper presents a simple method to determine the closed form base inertial parameters of general planar mechanisms. Based on mass transfer and moment of inertia transfer concepts, inertial parameter regrouping is physically interpreted. The relationships between inertial parameters of two jointed links are developed, leading to two propositions for inertia parameter regrouping of general moving links. For the unique configuration of moving links jointed to ground, two more propositions are presented. From these four propositions, base inertial parameters of a general planar mechanism can be easily formulated by inspection of the mechanism configuration. An equation to calculate the number of base parameters is also presented. Base parameters are estimated by this new method for several example planar mechanisms. This method gives all base parameters for general planar mechanisms, though in certain cases, it may overestimate the number of base parameters because certain kinematic configurations cause further regrouping of base parameters.