Real-Time Design Patterns in Virtual Simulations

In a virtual simulation, people and real system hardware interact with the simulated system. Introducing these real-world elements into the simulation environment imposes timing constraints which, from a software standpoint, places the design into the class of real-time systems. We develop two software design patterns for real-time virtual simulations: a variant of the model-view-controller architecture and a companion component pattern that facilitates the development of hierarchical simulation models, graphical displays, and network input/output (I/O ) that meet real-time constraints. These design patterns promote good programming practice and allow the performance of a design to be evaluated using rate mono-tonic analysis techniques. We also introduce selective abstraction and focused fidelity to reduce simulation development time and cost, while simultaneously improving runtime performance and the validity of simulation results