中文摘要：

分析了PRPR-2PRR、PRR-2PRR和4-PRR等三种平面冗余并联机构的驱动奇异位形，通过与平面3-PRR非冗余并联机构的比较，研究了采用不同机构冗余类型消除并联机构奇异位形的方法及其特点，为冗余并联机构的尺度综合、路径规划和控制提供了依据。

英文摘要：

The actuator singular configurations of three kinds of planar redundant parallel mechanisms （PRPR-2PRR, PRR-2PRR and 4-PRR） were discussed. Compared with planar non-redundant 3-PRR parallel mechanism, the methods and characteristics for different types of redundancy in eliminating singularity configurations of parallel mechanism were studied. The analytical results can be of great useful to the dimension synthesis, trajectory planning and control of redundant parallel mechanism.