Composable models for simulation-based design

This article introduces the concept of combining both form (CAD models) and behavior (simulation models) of mechatronic system components into component objects. By connecting these component objects to each other through their ports, designers can create both a system-level design description and a virtual prototype of the system. This virtual prototype, in turn, can provide immediate feedback about design decisions by evaluating whether the functional requirements are met in simulation. To achieve the composition of behavioral models, we introduce a port-based modeling paradigm. The port-based models are reconfigurable, so that the same physical component can be simulated at multiple levels of detail without having to modify the system level model description. This allows the virtual prototype to evolve during the design process, and to achieve the accuracy required for the simulation experiments at each design stage. To maintain the consistency between the form and behavior of component objects. we introduce parametric relations between these two descriptions. In addition, we develop algorithms that determine the type and parameter values of the lower pair interaction models; these models depend on the form of both components that are interacting. This article presents the initial results of our approach. The discussion is limited to high-level system models consisting of components and lumped component interactions described by differential algebraic equations. Expanding these concepts to finite element models and distributed interactions is left for future research. Our composable simulation and design environment has been implemented as a distributed system in Java and C++, enabling multiple users to collaborate on the design of a single system. Our current implementation has been applied to a variety of systems ranging from consumer electronics to electrical train systems. We illustrate its functionality and use with a design scenario.