POLE-AXIS BASED SINGULARITY ANALYSIS OF SPHERICAL MECHANISMS

Instantaneous kinematics of complex multi-loop mechanisms is modeled by linear and homogeneous mappings whose coefficient matrices have also important static meanings. As a consequence, the analysis of these models is a mandatory step, during design, that can be implemented by using the superposition principle. Here, spherical mechanisms are considered. Their general instantaneous-kinematics model is written by exploiting the properties of the instantaneous pole axes and the superposition principle. Then, this general model is analyzed to deduce an exhaustive analytic and geometric technique for identifying all the singular configurations of these mechanisms