Methodologies for real-time discrete-event simulation

实时系统（RTS）是非常先进的计算机系统应用，其硬件和软件组件以紧密的方式交互。这种系统的手动开发是耗时的，容易出错，并且昂贵。不同的形式化方法已经提出了RTS的发展，但他们已被证明是难以应用的复杂性系统的规模。建模与仿真（M&S）技术和工具已被提出来解决这个问题，并已被证明是有用的验证和验证RTS，包括他们互动的环境。我们要调查系统的方法和自动化工具，使用基于模型的方法来开发RTS。我们有兴趣定义新的理论，方法和技术，用于构建仿真模型，以后可以应用于实时环境中，并在系统中集成复杂的物理系统与RTS，结合正式建模技术和仿真。虽然在这方面作出了一些努力，但许多问题仍然悬而未决。主要的问题是，所提出的解决方案都没有考虑瞬时过载，检查时序约束和容错的问题。这需要定义新的理论、算法和工具，以保证在指定的时间限制内对输入做出响应，支持故障并提供优雅的降级。我们还将分析如何定义实时模型，并为执行模型提供自动验证，包括连续和混合系统的方法。我们将建立一套工具，可用于开发实时软件，并与硬件在环仿真，这将被用作我们的理论框架的概念验证。该研究有可能影响各种应用领域（通信，应急规划，交通控制，生物医学等）。

Real-time systems (RTS) are very advanced computer system applications with hardware and software components interacting in a tight fashion. The manual development of this kind of systems is time consuming, error prone, and expensive. Different formal methods have been proposed for RTS development, but they have shown to be difficult to apply as the complexity of the system scales up. Modeling and Simulation (M&S) techniques and tools have been proposed to address this issue and have been proven to be useful to verify and validate RTS, including the environment they interact with. We want to investigate systematic methods and automated tools to develop RTS using a model-based methodology. We are interested in defining new theories, methods and techniques for building simulation models that can later be applied in real-time environments, and in systems integrating complex physical systems with RTS, combining formal modelling techniques and simulation. Although several efforts exist in this area, many questions remain open. The main issue is that none of the proposed solutions has considered problems of transient overloading, checking of timing constraints, and fault tolerance. This requires defining new theories, algorithms and tools to guarantee responses to inputs within specified time constraints, supporting faults and providing graceful degradation. We will also analyze how to define real-time models, and we will provide automatic verification for the executing models, including methods for continuous and hybrid systems. We will build a set of tools that can be applied to develop real-time software, and simulations with hardware in-the-loop, which will be used as a proof-of-concept of our theoretical framework. The research has the potential to influence a variety of applications fields (communication, emergency planning, traffic control, biomedical, etc).