An automatic definition method was proposed for adding the datum to assemble similar components’models,to solve the automatic assembly of models from different sources and with different processes of modeling under the distributed resources environment.The core of this method was achieved the geometries involved in assembly shared by the similar components’models and set criteria by them.The assembling geometries were found by traversing the models,and then the datums were added by them automatically.After that,the added datum was unified naming by traversing the feature tree of the model.Then,the automatic assembly of models was realized using the added datums.Meanwhile,took two gears with different processes of modeling and different structures as an example,the definition principle and process of assembly datum were studied.The features of six similar components in the single-stage cylindrical gear reducer were analyzed,and the corresponding programs were developed to accomplish the automatic definition of datum of the components in the single-stage cylindrical gear reducer and then they were assembled automatically.The result showed that the automatic definition of the datum could be completed effectively,without the limited of the modeling process and non-main structures.This method was feasible and efficient,which can provide support for knowledge fusion of the mechanical system under distributed resources environment.
