Precision Assembly Geometric Error Sensitivity Analysis Based on the Error Transformation Model for Precision Assembly

In the process of multistage precision assembly, geometric error of parts is one of the important factors influencing on the assembly precision, and the method to determine the geometric error's influence and the bottleneck assembly are the primary problems. In this paper, the pose change of the parts was analyzed to concern the mating surface geometric error caused by surface topography in two parts assembly, and to determine the mating error of the single process. Based on the multi-body system theory, an error transformation model of multistage assembly process was established; and then, a sensitivity analysis model of the assembly precision was built with matrix differential method to identify the main geometric errors for the assembly system. The method provides theoretical basis for precision assembly accuracy analysis and control. Finally, an example was presented to validate the established model.