Contact constraint representation and its reduction in kinematic model of assembly

In order to check the kinematic performance of an assembly, a kinematic model of assembly using contact constraint representation in configuration space is needed. In this model, the motion of a component resulting from the imposed contact constraint is represented by the region in configuration space. However, it is difficult to derive the motion of the assembly because many constraints make the kinematic model of assembly too complex. In order to derive an equivalent minimum model of the kinematic model of an 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 procedures 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 a 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.