A large workspace macro/micro dual parallel mechanism with wide-range flexure hinges

Abstract

Parallel mechanism systems as a type of promising precision devices have been widely used in the current researches. Especially, in many designs, the flexure hinges are utilized as passive joints in the parallel mechanisms instead of the conventional joints, which can provide significant accuracy promotion. In this paper, a dual parallel mechanism is introduced, in which a 6-PSS parallel mechanism and a 6-SPS one are integrated perfectly. Another typical feature of this dual parallel mechanism's is the adoption of wide-range flexure hinges as passive joints, which ensures the large workspace of the whole system and high precision motion without any backlash at the same time. The conceptual design of wide-range flexure hinges and the architecture of the whole system are presented firstly. Then the kinematics model of this dual parallel mechanism system is established via the stiffness model of individual wide-range flexure hinge. And the configuration of the control system is discussed based on the macro/micro dual control principle. Finally, the performances' test results are presented, which indicate this system's dual parallel architecture actuated by piezoelectric motors and PZTs respectively and nonbacklash design ensure nanometer scale precision over the cubic centimeter workspace.