冗余驱动支链实现空间6自由度并联机构刚度设计理论  

Theory of Stiffness Synthesis by Adding Redundant-actuated Limb on Spatial 6-DOF Parallel Mechanism

作　　者：张双双[1] 杨洪涛[1] 刘齐更[1] Zhang Shuangshuang;Yang Hongtao;Liu Qigeng(College of Mechanical Engineering. Anhui University of Science and Technology, Huainan 232001, China)

机构地区：[1]安徽理工大学机械工程学院,安徽淮南232001

出　　处：《机械传动》2019年第5期38-43,共6页Journal of Mechanical Transmission

基　　金：国家自然科学基金(51675004);安徽理工大学青年基金(QN201626)

摘　　要：机构的末端刚度特性对制造装备的定位精度、顺应性和动态特性等有十分重要的影响,为了消除机构奇异位形,使机构具有更大的承载能力、更高的刚度和精度、更好的动态特性等,常需要可控的机构刚度来满足不同的需要;在全自由度并联机构的基础上,分析通过增加冗余驱动支链实现末端刚度需求的设计方法。根据螺旋理论分析了支链单驱动副并联机构的逆雅克比矩阵,建立了驱动刚度到末端刚度的映射关系矩阵,分析了各支链刚度到机构末端刚度分量的叠加规律,并根据末端刚度需求建立了一种通过增加冗余驱动支链实现末端刚度要求的方法;最后通过Stewart并联机构案例对上述理论进行了验证,实现了末端刚度接矩阵解耦的设计要求。The end stiffness characteristic of the mechanism has great influence on its positioning accuracy, compliance character and dynamic properties. In order to eliminate the configuration singularity, as well as to enhance its stiffness and accuracy, better dynamic property, a controllable stiffness of the mechanism is often required to satisfy different situations. On basis of full degree of freedom parallel mechanism, the design method by adding redundant actuated limbs to realize the end stiffness requirement is analyzed. Ac cording to screw theory, the inverse Jacobian matrix of parallel mechanism with limb single drive is ana lyzed, the mapping relationship matrix from the actuation to the end-effector stiffness is established. Then, the superposition rule of stiffness of each limb to the end stiffness comp on ent of the mecha nism is analyzed. According to the end stiffness requirement, a stiffness synthesis method by adding redundant-actuated limbs to realize the end stiffness requirement is established. Finally, the Stewart parallel platform is adopted to verify this synthesis method, the design requirement of the end stiffness matrix decoupling is realized.

关 键 词：刚度综合 冗余驱动 并联机构 刚度分解 

分 类 号：TH112[机械工程—机械设计及理论]