Geometric precision visualization and realization technology in virtual assembly system

To deal with the disadvantages of geometric precision expression in tolerance design process, by analyzing the precision information such as geometric deviation, tolerance domain and tolerance grade, a visualization method for dimension and geometric precision based on color perception and annotation expression was proposed. Through analysis of geometric model, precision model and 3D annotation model in assembly system, geometric precision visualization model as well as mapping relationship between precision information and color value were established. Thus the association problem on visualization model, geometric model and 3D annotation model was solved. By means of virtual environment's rendering technology, geometric precision visualization of germetric error relative to error limit was realized, and absolute geometric precision visualization reflecting tolerance grade was also realized. The perceptibility and interaction of geometric precision in virtual assembly system was improved. The related model and algorithm were realized in prototype system and verified by examples.