Precision predicting and computer aided adaptive assembly

Precision predicting is a new methodology for precision verification and validation of product. Considering the dimension and geometric deviation of assembled part, the precision predicting model is built by assembly deviation sources explaining and deviation propagation route modeling. The deviation source during assembly process is mainly explained by dimension torsor and deviation torsor that are built in common coordinate system, and the deviation propagation rout is modeled by weighted deviation graph. The weighted deviation graph contains vertexes that refer to functional geometry and mating geometry and edges that refer to dimension and geometric constraint; besides, the edge weight is calculated by tolerance evaluation along specific functional direction. In addition, the process of computer aided adaptive assembly method is introduced, and the proper index for assembly precision and accuracy is discussed.