Advanced Methodologies for Real-Time Discrete Event Modelling and Simulation

实时离散事件建模和仿真的先进方法

• 批准号: RGPIN-2015-06204
• 负责人: Wainer, Gabriel
• 金额: $ 3.64万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=667948
• 关键词: Advanced; Methodologies; Real; Time; Discrete

Embedded real-time systems are built as sets of components interacting with their surrounding environment. These are highly reactive systems, where the decisions can lead to catastrophic consequences for goods or lives (industrial automation, transport, robotics, etc.). In these systems, not only correctness is critical, but also the timing for executing the system tasks. Modeling and Simulation has proven to be a practical approach to verification of these systems with reduced costs and risks. Formal modeling and simulation provides even better results as the software artifacts can be built faster and safer. In particular, the Discrete-EVent Systems specification formalism (DEVS), a formal modeling and simulation framework based on generic dynamic systems concepts, is suitable to deal with these issues. ***Recent research has been oriented in using DEVS as a framework for Real-time systems development method. In addition, DEVS theory has been extended by formulating a rigorous theory of quantized systems in DEVS. Nevertheless, none of the existing DEVS environments and formalisms used for real-time systems has considered well-known problems in RT applications, for instance, fault tolerance, sensor replication or transient system overloading. The occurrences of system failures usually generate new real-time alarm tasks dynamically, generating a task load that cannot be supported by the system. Several techniques have been proposed to solve this problem. For instance, the techniques of imprecise computation allow to provide controlled degradation under transient overloads (by dividing the tasks in a mandatory part to provide basic results, and an optional part to improve the results obtained; also multiple versions of the same task can be provided, using a different version depending on the present load). ***The goal of our research program is to combine these theoretical frameworks, providing a technique for imprecise real-time computing based on DEVS. From the methodological point of view, we are interested in developing a theory of dynamic real-time DEVS using imprecise computing. The goal is to provide security, reduction in the development times, and the advantages of a formal framework to develop simulations. The results of the simulated system can be applied in the development in the real-time system. ***From the practical point of view, we expect to provide a set of tools that can be applied to develop real-time software and simulations with hardware-in-the-loop (requiring real-time response). By invoking appropriate execution engines, we will provide the ability to execute models in both logical time (the usual simulation clock) and real time (constrained to wall-clock time). These tools can be applied to a wide range of applications, ranging from mobile communication, emergency planning or traffic control systems.

嵌入式实时系统被构建为与周围环境交互的组件集。这些是高度反应性的系统，其决策可能会对商品或生命造成灾难性后果（工业自动化，运输，机器人等）。在这些系统中，不仅正确性是至关重要的，而且执行系统任务的时间。建模和仿真已被证明是一种实用的方法来验证这些系统，降低成本和风险。形式化建模和仿真提供了更好的结果，因为软件工件可以更快、更安全地构建。特别是，离散事件系统规范形式主义（DEVS），一个正式的建模和仿真框架的基础上通用的动态系统的概念，是适合于处理这些问题。* 最近的研究一直致力于使用DEVS作为实时系统开发方法的框架。此外，通过在DEVS中制定严格的量子化系统理论，DEVS理论得到了扩展。然而，没有一个现有的DEVS环境和用于实时系统的形式主义已经考虑了众所周知的问题，在RT应用程序中，例如，容错，传感器复制或瞬态系统过载。系统故障的发生通常会动态地产生新的实时告警任务，从而产生系统无法支持的任务负载。已经提出了几种技术来解决这个问题。例如，不精确计算的技术允许在瞬时过载下提供受控的降级（通过将任务划分为提供基本结果的强制部分和改进所获得的结果的可选部分;还可以提供相同任务的多个版本，取决于当前负载使用不同版本）。* 我们研究计划的目标是将这些理论框架联合收割机，提供一种基于DEVS的不精确实时计算技术。从方法论的角度来看，我们有兴趣发展一个理论的动态实时DEVS使用不精确计算。我们的目标是提供安全性，减少开发时间，以及开发模拟的正式框架的优势。仿真结果可用于实时系统的开发。* 从实践的角度来看，我们希望提供一套工具，可用于开发实时软件和硬件在环仿真（需要实时响应）。通过调用适当的执行引擎，我们将提供在逻辑时间（通常的模拟时钟）和真实的时间（限制为挂钟时间）中执行模型的能力。这些工具可以应用于广泛的应用，从移动的通信，应急规划或交通控制系统。