A Constraint Satisfaction Problem in Real-Time Collaborative Assembly Modeling

Collaborative assembly modeling has emerged as a stream of collaborative CAD research and development. Yet, it is still not clear how constraint satisfaction should be implemented in real-time collaborative assembly modeling, even though intensive research in geometric constraint satisfaction has been extensively conducted. To this end, this paper formally describes the constraint satisfaction problem in the context of real-time collaborative assembly modeling, and presents a method for the problem solving in support of collaborative assembly computation for constraint satisfaction. Overall, this method consists of a proposal of computing protocol and an incremental constraint satisfaction approach. In particular, the rule-based computing protocol is deliberately designed to safeguard model consistency via an incremental modeling sequence. Governed upon the computing protocol, a two-phase incremental constraint satisfaction approach of new contents is introduced to enhance computation efficiency in the multi-user involved modeling process. The proposed method has been incorporated into the implementation of an Internet-based real-time collaborative assembly modeling system.