Type Synthesis of Fully Decoupled Three Translational Parallel Mechanism with Closed-Loop Units and High Stifness

作     者：Shihua Li Sen Wang Haoran Li Yongjie Wang Shuang Chen Shihua Li;Sen Wang;Haoran Li;Yongjie Wang;Shuang Chen

作者机构：Hebei Provincial Key Laboratory of Parallel Robot and Mechatronic SystemsYanshan UniversityQinhuangdao 066004China 

出 版 物：《Chinese Journal of Mechanical Engineering》 (中国机械工程学报（英文版）)

年 卷 期：2023年第36卷第5期

页      面：231-247页

核心收录：

学科分类：08[工学] 080203[工学-机械设计及理论] 0802[工学-机械工程] 

基　　金：Supported by National Natural Science Foundation of China(Grant No.52275032) Key Project of Hebei Provincial Natural Science Foundation of China(Grant No.E2022203077) Hebei Provincial Key Research and Development Plan of China(Grant No.202230808010057) 

主　　题：Screw theory Three translational parallel mechanism Full decoupled Closed-loop units High stifness 

摘      要：In order to solve the problem of weak stifness of the existing fully decoupled parallel mechanism, a new synthesis method of fully decoupled three translational (3T) parallel mechanisms (PMs) with closed-loop units and high stifness is proposed based on screw theory. Firstly, a new criterion for the full decoupled of PMs is presented that the reciprocal product of the transmission wrench screw matrix and the output twist screw matrix of PMs is a diagonal matrix, and all elements on the main diagonal are nonzero constants. The forms of the transmission wrench screws are determined by the criterion. Secondly, the forms of the actuated and unactuated screws can be obtained according to their relationships with the transmission wrench screws. The basic decoupled limbs are generated by combination of the above actuated and unactuated screws. Finally, a closed-loop units construction method is investigated to apply the decoupled mechanisms in a better way on the high stifness occasion. The closed-loop units are constructed in the basic decoupled limbs to generate a high-stifness fully decoupled 3T PM. Kinematic and stifness analyses show that the Jacobian matrix is a diagonal matrix, and the stifness is obviously higher than that of the coupling mechanisms, which verifes the correctness of the proposed synthesis method. The mechanism synthesized by this method has a good application prospect in vehicle durability test platform.