Constraint Management in Distributed Product Models

摘要

Computer models for complex mechanical products are often distributed among design team members who use disparate software tools. Communication between these tools has previously been limited to occasional file transfer. However, recent research has begun to allow software applications to communicate automatically to maintain the integrity of the evolving product model. Constraint satisfaction plays an important role in maintaining design integrity. This paper describes a methodology for representing and satisfying constraints in distributed design environments. The methodology employs a propagation method that allows the solution steps to be posed as messages between applications. The propagation methods also facilitate support for a broad range of object and constraint types. We show how the method can be applied to both algebraic and geometric constraints. We also describe a method called symbolic propagation that is used for solving coupled and under-constrained systems. A distributed assembly design system that was implemented to demonstrate and validate the methods is also described.