Feature-Based Assembly Mating Reasoning

This paper presents a feature-based method to obtain assembly mating relations between a set of polyhedral components. Previous research in assembly planning has assumed that these assembly mating relations, or equivalent information such as the final assembled configuration of the components, is provided as part of the problem input. This paper addresses the case where only the component geometry is provided, which can arise in product maintenance or emergency repair applications where the originally designed assembly mating relations are no longer valid, and in robotic autonomous construction applications. The basis of the method is to represent components in terms of form features using a feature recognition method based on Alternating Sum of Volumes with Partitioning (ASVP) decomposition. Feature recognition is applied to each component to obtain its Form Feature Decomposition (FFD), which is a hierarchy of positive and/or negative form features. Positive form features of each component are compared with negative form features of other components to obtain mating relations between pairs of features. Multiple feature matings between the same pair of components are merged into component matings, which comprise the assembly mating relations. A backtracking search generates all feasible assembly configurations from the component matings.