面向骨折手术的三支链六自由度并联机构设计  

Developing Three-Legged Six-Degree-of-Freedom Parallel Mechanism for Bone Reduction Surgery

作　　者：王蕊[1] 霍欣明 连宾宾[1] 宋轶民[1] 孙涛[1] Wang Rui;Huo Xinming;Lian Binbin;Song Yimin;Sun Tao(Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education,Tianjin University,Tianjin 300350,China)

机构地区：[1]天津大学机构理论与装备设计教育部重点实验室,天津300350

出　　处：《天津大学学报（自然科学与工程技术版）》2022年第3期273-282,共10页Journal of Tianjin University：Science and Technology

基　　金：国家重点研发计划资助项目(2018YFB1307800);国家自然科学基金资助项目(51775367);天津市临床医学研究中心资助项目(18PTLCSY00080);天津市重点研发计划京津冀三地协同创新研发项目(18YFSDZC00010);天津市科技计划资助项目(18YFZCSF00590).

摘　　要：随着微创技术和生物学固定技术的发展,创伤骨折手术中愈加需要术中精准定位,以确保内固定物能够精确和微创地固定骨折断端.其中,利用六自由度并联机构进行骨折断端的复位和固定是实现微创精准骨折手术的重要手段,也是未来骨折手术的发展趋势.现有的由6条支链构成的六自由度并联机构存在质量大、医学影像设备扫描后伪影严重等系列问题,提出和设计少支链六自由度并联机构成为研究热点.本文借助有限旋量理论构型综合出一类三支链六自由度并联机构,并进行了其拓扑结构和运动学性能设计.首先,利用有限旋量描述六自由度并联机构及其支链末端的运动,通过有限旋量理论的结合定律和交换定律获得可行支链的标准型和衍生型,通过定义支链装配条件和配置驱动关节,综合出一类三支链六自由度并联机构;然后,定义了优选准则,借助瞬时旋量理论对优选出的5种三支链六自由度并联机构进行了位置逆解、工作空间和速度分析;最后,以运动/力传递率在给定工作空间内的均值与方差为目标函数,考虑并联机构的拓扑结构对运动学性能的影响因素,开展了三支链六自由度并联机构的拓扑结构与运动学性能的一体化设计.上述工作为后续三支链六自由度并联机构的物理样机建造与实验研究提供了理论基础.With the development of minimally invasive and biological fixation technologies,precise intraoperative positioning is increasingly required in trauma and fracture surgery to ensure that the internal fixation object can accurately and minimally perform invasive fracture fixation.The use of a six-degree-of-freedom parallel external fixation robot for fracture reduction and fixation is an effective method to achieve a minimally invasive and precise reduction surgery,and it is also the future development trend of fracture surgery.The existing six-degree-of-freedom parallel mechanism comprising six branches has problems such as heavy weight and creating serious artifacts in medical imaging scans.Proposing and developing a six-degree-of-freedom parallel mechanism with fewer branches has become a research hotspot.This paper develops a three-legged six-degree-of-freedom parallel mechanism using configuration synthesis,the finite screw theory,and designs based on its topology and kinematics performance.First,the finite screw theory is used to describe the motion of the six-degree-of-freedom parallel mechanism and the end of its branch.The standard and derivative versions of the feasible branch are obtained through the synthesis and exchange law of the finite screw theory.The assembly conditions of the branch are defined,and the drive joints are configured to obtain five types of three-legged six-degree-of-freedom parallel mechanisms.Then,the instantaneous screw theory was used to analyze the inverse kinematics,workspace,and speed analysis of these five types of parallel mechanisms.Finally,the integrated design of topology and kinematic performance of the three-legged six-degree-of-freedom par-allel mechanism were determined,by taking the mean and variance of the motion/force transmission rate in a given workspace as the objective function and considering the influence factors of the topology on the kinematic perform-ance.This work provides a theoretical basis for the physical prototype construction and experimental resear

关 键 词：三支链六自由度并联机构 有限限量 瞬时旋量 构型综合 运动学设计 

分 类 号：TK448.21[动力工程及工程热物理—动力机械及工程]