CONSTRAINT REDUCTION BASED ON VIRTUAL FEATURE IN ASSEMBLY MODEL

With kinematic analyses of assembly, it is difficult to derive the motion of the assembly because many constraints make the kinematic model of assembly complex. In order to derive an equivalent minimum model of the kinematic model of assembly, and to decrease the computational complexity, a constraint reduction procedure for the kinematic model of assembly in configuration space is proposed as follows: first, mapping rules of the kinematic model are proposed in order to realize the mapping from a feature-based kinematic model to a kinematic model in configuration space. Second, constraint reduction procedure in configuration space and a method for deriving the minimum kinematic model in configuration space are proposed. Third, based on the constraint reduction procedure in configuration space, feature-based constraint reduction is proposed by introducing virtual feature; it is confirmed that TTRS reduction rules are valid feature-based constraint reduction rules. Using this reduction procedure, a method for deriving the feature-based minimum kinematic model is proposed. Fourth, using the feature-based minimum kinematic model and the mapping rule of the kinematic model, a method for deriving the minimum kinematic model in configuration space is proposed. Finally, in order to confirm the usefulness of the proposed constraint reduction, it is applied to an example of the kinematic model of assembly.