A framework for the design and specification of hard real-time, hardware-in-the-loop simulations of large, avionic systems

High-level design tools for the design and specification of avionic systems and real-time systems currently exist. However, real-time, hardware-in-the-loop simulations of avionic systems are based upon principles fundamentally different than those used to design avionic systems and represent a specialized case of real-time systems. As a result, the high-level software tools used to design avionic systems and real-time systems cannot be applied to the design of real-time, hardware-in-the-loop simulations of avionic systems. For this reason, such simulations of avionic systems should not be considered part of the domain containing avionic systems or general-purpose real-time systems and should be considered as an application domain unto itself for which design tools are unavailable. To fill this void, this dissertation proposes a framework for the design and specification of real-time, hardware-in-the-loop simulations of avionic systems. This framework is based upon a new specification language called the Simulation Architecture Description Language. This specification language is a graphical language with constructs and semantics defined to provide the user with the capability to completely define the simulation and its software execution characteristics at various levels of abstraction. The language includes a new method for combining precedence constraints for a single software process. These semantics provide a more accurate description of the behavior of software systems having a dynamic job structure than existing semantics. An environment that supports the execution of simulation software having the semantics defined within this language is also described. A toolset that interfaces to the language and provides additional functionality such as design analysis, schedulability analysis, and simulation file generation is also discussed. This framework provides a complete design and specification environment for real-time, hardware-in-the-loop simulations of avionic systems.