Conceptional Design and Kinematics Modeling of a Wide-Range Flexure Hinge-Based Parallel Manipulator

Although micro-motion parallel manipulators have been used widely, their special architectures make it impossible to be applied in the condition demanding relative large workspace. In this paper, a novel large workspace flexure hinge-based parallel manipulator is presented, which can attain the sub-micron scale accuracy over the cubic centimeter workspace. This manipulator system is a 6-PSS parallel mechanism, in which piezoceramic motors actuate the prismatic joints, precision linear encoders detect the actuation displacements, and as the key technology, a kind of novel wide-range flexure hinges are utilized as passive spherical joints. Because of the adoption of wide-range flexure hinges, the whole system features large workspace differing from the conventional micro-motion flexure hinge-based parallel manipulators. The kinematics analysis of the whole mechanism is performed based on the stiffness model of the flexure hinges via FEM theory. The wide-range flexure hinges move over large space during the course of self-deformation, so the kinematics model is a typical geometrical nonlinear problem. In this paper, a Newton-Raphson increment iterative scheme for the kinematics model solution procedure of the whole mechanism is presented based on Updated Lagrange Formulation. And finally, the numerical calculation results about the theoretical model are given.