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An Improved Method of Physical Interaction and Signal Flow Modeling for Systems Engineering



Mehdi Dadfarnia, Conrad E. Bock, Raphael Barbau


Many engineering disciplines that interact with systems engineering use simulation tools to build models based on nist-equations, which are solved to predict physical and informational behavior over time. Both kinds of engineering are concerned with physical and informational behaviors within systems, but focus on different aspects of these behaviors, discouraging communication and producing conflicting or erroneous models. Systems engineering models usually specify how components are interconnected and broken down into subcomponents (system structure), limiting behaviors to occur within components or between interconnected components. Equation-based simulation models have nist-equations relating variables that are not limited by system structure. The gap between systems and nist-equation-based simulation models is smaller for simulation models that incorporate structure, in particular those covering physical interaction and signal flow. Unfortunately, adoption of this kind of simulation has been slowed by a lack of simulation modeling methods based on physical principles. This paper lays out an improved method for developing physical interaction and signal flow simulation models that align with systems models. To capture the underlying physical principles, this method emphasizes the transformation and transmission of conserved physical substances and numeric information within system structures, with nist-equations chosen to describe these processes. Simulation models are easier to develop this way and are better aligned with systems engineering models. The method is presented using the Systems Modeling Language, extended in prior work for physical interaction and signal flow modeling that supports code generation to widely-used simulation tools.
Conference Dates
March 22-24, 2016
Conference Location
Huntsville, AL
Conference Title
Conference on Systems Engineering Research (CSER 2016)


System structure, physical simulation, lumped equation modeling
Created October 31, 2016, Updated February 19, 2017