3自由度转动广义解耦并联机构构型综合

Type Synthesis of Three Degrees of Freedom Rotational Generalized Decoupling Parallel Mechanism

基于传统解耦并联机构的定义,并结合3自由度转动解耦并联机构的研究现状,提出一种广义解耦的概念。在广义解耦中,对机构的输出参数进行限定,同一输出参数对应的运动可叠加,保证移动解耦或者转动解耦并联机构具有更好的输出特性。根据机构运动与分支运动之间的关系,提出一种新型广义解耦并联机构型综合方法,包括分支运动规划、分支型综合、分支组合三个过程。根据并联机构中的运动副特性,得到分支实现单一轴线方向转动的条件,并基于该转动条件提出一种转动单元的概念。基于广义解耦并联机构的定义,选取一组满足要求的参数作为3自由度转动解耦并联机构的输出参数,利用提出的型综合方法,并结合转动单元的概念,对3自由度转动广义解耦并联机构进行型综合并得到了大量3自由度转动广义解耦并联机构构型,同时验证了广义解耦的概念以及型综合方法的可行性和有效性。该研究为解耦并联机构的型综合提供了理论基础和新的设计方法。

Based on the traditional definition of decoupling parallel mechanism,and combined with the research status of three DOFs rotational decoupled parallel mechanism,a new concept of generalized decoupling is proposed.In the definition of generalized decoupling,the output parameters of parallel mechanism are demanded to meet the requirements that the different movements of same output parameter can be directly superposed,so as to obtain better output characteristics for translational or rotational decoupled parallel mechanism.According to the relationship between the movements of parallel mechanism and its branches,a new method of type synthesis is proposed for decoupled parallel mechanism,including the programming and distribution of branches＇ movements,configuration design and combination of branches.On the basis of characteristics of kinematic pairs in parallel mechanism,the conditions for branch to achieve single rotational DOF around one axis are analyzed and obtained.According to the rotation conditions of parallel mechanism,a new concept of rotation unit is proposed.Based on the definition of generalized decoupling parallel mechanism,a set of parameters that meet the requirements are selected to be the output parameters of the three DOFs rotational parallel mechanism.By applying the new method of type synthesis and coupled with the concept of rotation unit,tons of three DOFs rotational generalized decoupling parallel mechanisms are worked out.Thus,the concept of generalized decoupling and the new method of type synthesis are proved to be feasible and effective.The research provides a theoretic foundation and new design approach for type synthesis of decoupled parallel mechanism.