Analysis for the static stiffness of a 3DOF parallel compliant micromanipulator

The compliant micromanipulator requires very high positioning accuracy, which mainly depends on its static stiffness. Aiming at the shortcomings in existing analysis for static stiffness of compliant micromanipulators, compliance matrix method in structural analysis is applied. To specify it, compliance models of the flexible elements are determined firstly; the static stiffness matrix of the end-effector in relation to the reference coordinate system is obtained through the transformations of a series of different coordinate systems and the establishment of equilibriums of displacements and forces in unit nodes of the robot. At last, taking a 3DOF parallel compliant micromanipulator for instance, its static stiffness is discussed. The analysis shows that the result by using the compliance matrix method is very rapid and more approaches to the essence of compliant mechanisms.