Stiffness modeling of a spatial 3-DOF compliant parallel micromanipulator

The stiffness modeling for a compliant parallel manipulator (CPM) is very important since it provides a basis for the characterization of static, modal, and dynamic behavior of the CPM. This paper presents the stiffness modeling of a three-prismatic-revolute-cylindrical (3-PRC) CPM with orthogonally mounted actuators, that is designed to provide three spatial translational DOF for nano scale manipulation. A straightforward method is developed to establish the analytical stiffness model for a spatial CPM by considering the compliance of each compliant element, which is then applied to stiffness modeling of the 3-PRC CPM. Furthermore, the finite element analysis is carried out to validate the developed model. And to demonstrate the utility of the stiffness model, the influence of architectural parameters on stiffness factors is analyzed, which is valuable for a cost-effective design of the CPM.