This article promote the usual comprehension about singularities of general parallel mechanisms. Usually there are three kinds of singularities, namely, configuration space singularity, actuator singularity and end-effector singularity. Roughly speaking, the first one is related to the topological property of configuration space. The second one is caused by the introducing of actuated joints and passive joints. The last one depends on the choice of end-effector. However, rigorous discussion and precise definition of the above three kinds of singularities haven't been made. In this paper we give an accurate definition for these three kinds of singularities and find that the first two kinds of singularities are independent of different embedding. As a fact the last two kinds of singularities can be further divided into degenerate and nondegenerate case according to the second order property of some kind of Morse function which is more easy to construct than that proposed by Park. Several real examples are studied which verify our theory of singularity analysis.
展开▼
