A New Symbolic Method to Determine Base Inertia Parameters for General Spatial Mechanisms

Symbolic estimation of base inertia parameters is attractive. All published symbolic methods, however, are complicated and can only be applied to rotational joints and translational joints. This paper presents a new simple symbolic method to determine base inertia parameters for general mechanisms that include spherical joints and universal joints. The concepts of mass transfer and moment of inertia transfer are successfully extended to spatial joints and four propositions are developed based on the concepts. With the four propositions, a set of symbolic base parameters can be determined directly from the inspection of the joint configurations of general mechanisms. The determination of symbolic base inertia parameters of a spatial four bar mechanism is presented as an application example.