Although a planar pair might theoretically be included, this would impose no constraint and thus be equivalent to an opening in the kinematicchain.
尽管理论上还可以包括平面，但平面却不能加以约束，因此只相当于开式运动链。
2
The spectrums of degree, structural component and multiple hinges are defined according to the basic parameters of planar closed kinematicchain with multiple hinges.
根据含复铰平面闭式运动链的基本参数，定义了度谱、构件谱和复铰谱。
3
With the linear graph and adjacent matrix method of graph theory, the possible forms of this mechanism are discussed by analyzing that of kinematicchain with 4~8 links connected by planar low pair.