Abstract
Adopting a screw algebra-based approach, this paper analyzes the stiffness of flexure hinges and the resultant reaction force (RRF) of a rigid origami-inspired modified Wren parallel mechanism with flexure hinges (WPM) capable of helical motion. Analytical solution of the RRF, consisting of force in the direction of translation and torque around the axis of helical motion, applied to the platform of the WPM by flexure hinges is revealed. Simulation is implemented to verify the theoretical analysis of the RRF of the WPM. To further validate the theoretical model, multi-layered aluminium composite panel is selected for fabricating flexure hinges and the WPM capable of high precise motion and large force transmission. The resistive torque of the flexure hinge and the RRF of the WPM are measured and compared with the analytical solution. Both simulation and experimental results reveal that the RRF of the WPM resulted from flexure hinges is precisely modelled using the screw algebra-based approach. A novel bipedal robot integrating the WPM is developed for applications in extreme environment where pneumatically actuated systems are preferred over electrical machines and drives. This study paves a way for developing novel WPM-integrated robotic devices and precisely modelling the coherent stiffness of the rigid origami-inspired parallel mechanisms with flexure hinges.
