A Geometric Method of Singularity Analysis for Parallel Robots
并联机器人奇异位形分析的几何方法

Using the language of differential geometry, this paper provides a fine classification of singularities of general parallel robots. Based on the relations between singularity manifolds and singularity distributions, these singularities are further subclassified into first-order singularities and second-order ones. Furthermore, the second-order singularities can be distinguished as degen-erate or nondegenerate singularities by whether they form continuous curves on configuration manifolds. This paper also gives an insight into the degenerate singularities, which can sometimes be a source of danger not only to the mechanism itself but also to workers to operate the mechanism. Finally, a planar two degrees-of-freedom mechanism with one redundant actuator is given to illu-minate the method.