Optimal usage of CORBA for soft real-time simulation applications

The OPERA Platform is a CORBA-based distributed real-time computing platform to easily couple existing simulation models and run them in a federated mode on a synchronized time-basis. The first and primary application has been simulation-based training for chemical operators. The Platform is based on CORBA middleware to enable a standard and cost-effective integration of existing simulation models available in heterogeneous environments (diverse hardware platforms and multiple programming languages such as C, C++, Java or FORTRAN). In addition, the OPERA Platform provides built-in CORBA facilities for time-based exchange of simulation data, the synchronization of the logical simulation time, model integration support and system monitoring at run-time. First, the paper discusses the overall design requirements such as provision of a realistic system view to operators, i.e. meet soft real-time deadlines in spite of complex computing process models, cost-effective integration of heterogeneous legacy simulation software and applications and integration of hybrid simulation models. The paper shows how market constraints required a cost-effective solution, heavily relying on widespread standards, and offering open interface that enable a close integration with Web-based solutions as well as MS-Windows based office systems. This combined requirement set of both high performance, real-time, flexibility and low-cost is not met satisfactorily by the Run-time Infrastructure of the HLA. Thus, the design solution has been, though using the basic HLA time management concepts, to build the OPERA Platform from scratch in a standard IT environment and to carefully apply proven standard object technology. Finally, the paper presents the architecture of the OPERA platform and gives a detailed insight into the design approach for the optimized simulation protocol deducted from intensive benchmarking of CORBA products.