完全各向同性解耦2T2R型并联机器人构型综合

Structural synthesis of fully isotropic and decoupled 2T2R parallel robot

为得到完全各向同性解耦并联机器人构型,基于GF集理论提出一种简单而有效的构型综合方法.阐述GF集的基本概念、运算法则以及转动特征存在条件;给出机构输入运动副选择原则和分支设计准则,确保了并联机构运动各向同性及解耦性;根据该构型综合原理,完成2T2R四自由度完全各向同性解耦并联机构型综合,得到大量新构型;针对所综合的一种新型并联解耦机构,基于螺旋理论求得该机构运动输出,通过求解到的雅克比矩阵,验证该机构的完全各向同性,证明了该构型方法的有效性.

To obtain fully isotropic and decoupled structures of parallel robot, a very simple but very effective structural design is proposed based on G_F set. The basic concept of G_F set, algorithms and the type synthesis principle, requirements for rotation based on G_F set are firstly introduced. Secondly the selection criterion of the input pair and type synthesis principle of decoupled branches are given, therefore it ensures that the various branches＇input are isotropic and decoupled. According to the type synthesis theory, structural synthesis of 2T2R four degrees of freedom decoupled parallel mechanism is finished. Simultaneously, a lot of new mechanisms are attained. Finally, the screw theory is applied to analyze kinematic characteristic of a parallel mechanism synthesized above. The expression of the Jacobian matrix is deduced which validated the decoupling feature of the mechanism. In addition it demonstrates the effectiveness of the novel method of structural synthesis for parallel mechanisms.