Stiffness Modelling and Analysis of a Redundantly Actuated Parallel Manipulator
摘要
Redundantly actuated parallel manipulator (RAPM) has been proved to have comparative advantages of higher rigidity and higher payload over other parallel manipulators. This paper is to establish a sufficient accurate stiffness modelling to evaluate the stiffness of the 2UPR-2RPS RAPM. Firstly, the structure of the 2UPR-2RPS RAPM is briefly introduced, followed by some necessary kinematic definitions. Next, a stiffness modelling of 2UPR-2RPS is established by including the compliances of all joints and limb structures. And a reasonable index is constructed to evaluate the stiffness of the 2UPR-2RPS RAPM. Finally, a set of stiffness experiments is carried out to verify the effectiveness of the proposed stiffness modelling of the 2UPR-2RPS. The results indicate that the relative errors between the proposed stiffness modelling and the experimental value are less than 6%. This indicates that the proposed stiffness modelling possesses sufficient accuracy and thus can be used to analyze the stiffness of the 2UPR-SRPS RAPM.