Integrated computer control system CORBA-based simulator FY98 LDRD project final summary report
The CORBA-based Simulator was a Laboratory Directed Research and Development (LDRD) project that applied simulation techniques to explore critical questions about distributed control architecture. The simulator project used a three-prong approach comprised of a study of object-oriented distribution tools, computer network modeling, and simulation of key control system scenarios. This summary report highlights the findings of the team and provides the architectural context of the study. For the last several years LLNL has been developing the Integrated Computer Control System (ICCS), which is an abstract object-oriented software framework for constructing distributed systems. The framework is capable of implementing large event-driven control systems for mission-critical facilities such as the National Ignition Facility (NIF). Tools developed in this project were applied to the NIF example architecture in order to gain experience with a complex system and derive immediate benefits from this LDRD. The ICCS integrates data acquisition and control hardware with a supervisory system, and reduces the amount of new coding and testing necessary by providing prebuilt components that can be reused and extended to accommodate specific additional requirements. The framework integrates control point hardware with a supervisory system by providing the services needed for distributed control such as database persistence, system start-up and configuration, graphical user interface, status monitoring, event logging, scripting language, alert management, and access control. The design is interoperable among computers of different kinds and provides plug-in software connections by leveraging a common object request brokering architecture (CORBA) to transparently distribute software objects across the network of computers. Because object broker distribution applied to control systems is relatively new and its inherent performance is roughly threefold less than traditional point-to-point communications, CORBA presented a certain risk to designers. This LDRD thus evaluated CORBA to determine its performance and scaling properties and to optimize its use within the ICCS. Both UNIX (Sun Solaris) and real-time (Wind River VxWorks) operating systems were studied. Performance of ICCS deployment was estimated by measuring software prototypes on a distributed computer testbed and then scaled to the desired operating regime by discrete-event simulation techniques. A study of CORBA protocols continues to guide software optimization as NIF software is being implemented and tested. The message-driven nature of distributed control places heavy demands on computers and network switches, so a complementary simulation of network architectures for several protocols was undertaken using a network modeling tool (OPNET Modeler). Additional workflow simulations were developed in a general simulation tool (Simprocess) to assess system behavior of high-stress operational scenarios. Understanding the risks and decisions that trade-off in designing the framework and supporting hardware architecture was enhanced by a concurrent program of simulation and prototype validation of the ICCS applied to the NIF example.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Defense Programs (DP)
- DOE Contract Number:
- W-7405-Eng-48
- OSTI ID:
- 8045
- Report Number(s):
- UCRL-ID-133243; 39DP02000; 98-ERD-065; ON: DE00008045
- Country of Publication:
- United States
- Language:
- English
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