Design Methodology for a Compliant Binary Actuated Parallel Mechanism with Flexure Hinges

This paper discusses the further development of a binary parallel manipulator named BaPaMan1 (Binary Actuated PArallel MANipulator), which is aimed at the improvement of the structural stiffness and allows task-adaptation. BaPaMan1 is a three DOF spatial parallel robot which comprises flexure hinges and Shape Memory Alloy (SMA) actuators to achieve a low-cost design, well suited for easy operation applications. Measurements have shown that this comes at the cost of poor structural stiffness and end effector accuracy. To counter these issues BaPaMan2 and BaPaMan3 have been developed and are elaborated within this work. During the design phase, an empirical FEA was used to improve the flexure hinge performance, in which relations between several design parameters and the stiffness of the entire system were analyzed. Finally, task-adaptation was achieved using a developed design methodology and parametric CAD model for BaPaMan3, which take advantage of deduced stiffness influencing equations.