Virtual assembly technologies based on constraint and DOF analysis

Assembly constraint is an important factor for product assembly. Constraint is not only necessary for accurate locating of parts but also an important way to realize assembly operation process in virtual assembly (VA) system. In this study, to realize VA reasonably, uniform representations of assembly constraint, equivalent relation between constraint and degree of freedom (DOF), and movable DOF reduction are defined. Several algorithms including based-constraint assembly relation recognition, assembly parts location solving under free and constrained spaces, and movement navigation are developed. These algorithms have been applied to integration virtual assembly environment (IVAE) software system. An example is illustrated, and the results prove that the algorithms provide a good support for the constraint treatments in IVAE and the high consistence between virtual and real assembly process is realized.