GF集是对机构末端的运动特征进行描述的集合.介绍GF集的基本概念、求交运算法则和基于GF集的并联机构构型理论.提出了基于GF集的三自由度移动并联机构构型方法.根据该构型理论,得到可构成三自由度移动并联机构的GF集的各种组成方式,并列举出具有确定运动特征的支链,利用这些支链构造了三自由度移动并联机构.最后,根据GF集的求交运算法则,分析了一种具有三自由度移动特征的并联机构.
A GF set is utilized to describe the kinematic characteristics of an end effector of a parallel mecha nism. The basic concept of GF set, intersection algorithms and the type synthesis principle based on GF set are first introduced. A new method for the type synthesis of 3-DoF (degree-of-freedom) translational par allel mechanisms based on GF set is then presented. According to the approach proposed in this paper, composing patterns of the GF set of 3 DoF translational parallel mechanisms are obtained. Kinematic limbs with specific kinematic characteristics that can be applied to construct 3-DoF translational parallel mecha nisms are then enumerated. The type synthesis of 3 DoF translational parallel mechanisms is developed using the feasible kinematic limbs in sequence. Finally, a novel 3-DoF translational parallel mechanism is analyzed through the intersection algorithms of GF set to demonstrate the methodology.