对三平移并联机构(3T并联机构)，提出一种冗余驱动支链的综合方法。采用螺旋理论，分析出3T并联机构发生内部奇异的所有可能情况；根据螺旋系线性相关性和并联机构不发生奇异的条件，系统综合出能消除3T并联机构内部奇异的冗余驱动支链类型，并针对不同的支链约束螺旋系和自由度，分别给出相应的冗余驱动支链位置和条数；利用该方法对消除3-RRUR内部奇异的冗余支链进行综合。研究结果表明，该方法简单、有效并可消除3T并联机构内部奇异。

A synthesis method of branched link with actuation redundancy for 3-translational parallel mechanisms (3T parallel mechanisms) is presented. All the possible inner singular situations are analyzed based on the screw theory. Then based on the linear relevance of screw system and the theory of singularity elimination by actuation redundancy, branched chains with actuation redundancy are synthesized systematically, which can eliminate the inner singularity for 3T parallel mechanisms. And according to the constraint screw system and degrees of freedom of the different added branched chains, the position and number of them is determined. Finally, branched chains with actuation redundancy are synthesized systematically which can eliminate inside singularity for 3-RRUR. by this method. The results show that this method is simple, effective, and can eliminate the singularity of the 3T parallel mechanisms.