Research on constraint-based virtual assembly technologies

In order to realize constraint-based virtual assembly operation,unified representations of assembly constraint,equivalent relationship between constraint and Degree of Freedom(DOF),and movement DOF reduction in virtual environment were proposed;and several algorithms on constraint treatment were put forward.Firstly,automatic recognition algorithm was applied to judge whether position and orientation relation between two geometrical elements of constraint were within tolerant errors extent.Secondly,to meet new constraint,position and orientation of active part was modified with minimum adjustment based on satisfying already affirmed constraints according to positioning solution algorithm.Finally,movement navigation algorithm based on generalized coordinate system was put forward,and part movement was guided according to assembly constraints.These algorithms have been applied to Integrated Virtual Assembly Environment(IVAE)system.Applications have indicated that the proposed algorithms could provide better support for constraint treatments in IVAE and has realized closer combination of virtual and real assembly process.