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 compone nt objects. By connecting these component objects to each other through the ir ports, designers can create both a system-level design description and a virtual prototype of the system. This virtual prototype, in turn, can prov ide immediate feedback about design decisions by evaluating whether the fun ctional requirements are met in simulation. To achieve the composition of b ehavioral models, we introduce a port-based modeling paradigm. The port-bas ed models are reconfigurable, so that the same physical component can be si mulated at multiple levels of detail without having to modify the system le vel model description. This allows the virtual prototype to evolve during t he design process, and to achieve the accuracy required for the simulation experiments at each design stage. To maintain the consistency between the f orm and behavior of component objects. we introduce parametric relations be tween these two descriptions. In addition, we develop algorithms that deter mine the type and parameter values of the lower pair interaction models; th ese models depend on the form of both components that are interacting. This article presents the initial results of our approach. The discussion is li mited to high-level system models consisting of components and lumped compo nent interactions described by differential algebraic equations. Expanding these concepts to finite element models and distributed interactions is lef t for future research. Our composable simulation and design environment has been implemented as a distributed system in Java and C++, enabling multipl e users to collaborate on the design of a single system. Our current implem entation has been applied to a variety of systems ranging from consumer ele ctronics to electrical train systems. We illustrate its functionality and u se with a design scenario.