Compositional Methods for the Control of Concurrent Timed Discrete-Event Systems

并发定时离散事件系统控制的组合方法

• 批准号: 412108828
• 负责人: Professor Dr.-Ing. Thomas Moor
• 金额: --
• 依托单位: Lehrstuhl für Regelungstechnik
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/412108828?language=en
• 关键词: Compositional; Methods; Control; Concurrent; Timed

The emergence of technological systems with more and more autonomous modes of operation and several communicating components brought the necessity of new approaches to their modeling and control in order to guarantee their correct behavior. Discrete-Event Systems are dynamical systems governed by asynchronous occurrences of events. Such systems are typically encountered in technological man made systems, such as automated transport systems, automated manufacturing, and logistics in general. These application areas have stimulated the development of supervisory control of DES. The term "supervisory Control" points to a control paradigm where the controller to be synthesized will disable certain events that may eventually lead to an unacceptable closed loop behavior, but will allow all other events. Referring to the multi-component structure of the typical target application, the main challenge in the synthesis of a supervisorycontroller is the exponential growth of the overall state set in terms of the number of components. This is addressed by compositional methods which avoid the explicit construction of an overall model. In their basic form, DES model the order of events and this is adequate to synthesise supervisor that guarantees safe operation of the system; e.g. for automated transport, a segment of a track shall only be used by one train at a time to be safe. However, for many applications performance explicitly relates to physical time; e.g. for automated transport, we are concerned about the overall throughput realised with all available trains and tracks. Here, the literature provides multiple modelling frameworks which differ in expressiveness. On the one end of the range, there are the Brandin-Wonham framework, which uses a global tick-event to represent the elapse of time, and there are timed events graphs (TEG), which are a specific type of Petri nets that translate to linear (max, +)-equations. For both frameworks, controller synthesis is well understood. However, being on the low end regarding expressiveness, both frameworks have severe limitations.With Brandin-Wonham, one cannot model concurrent system with multiple real-time clocks, and TEG cannot address logical decision making. In this research project, we will establish efficient methods for the control of timed DES that are more expressive than the Brandin-Wonham framework and TEG. Technically, we will consider so called (max, +)-automata and specific classes of timed Petri nets as base models, in order to develop modular and hierarchical approaches to supervisory control, including the respective synthesis algorithms. Our results will considerably enlarge the scope for model based controller synthesis of DES.

具有越来越多自主操作模式和多个通信组件的技术系统的出现，带来了对其建模和控制的新方法的必要性，以保证其正确的行为。离散事件系统是由异步事件发生控制的动态系统。这种系统通常在技术人造系统中遇到，例如自动化运输系统、自动化制造和一般的物流。这些应用领域刺激了DES监督控制的发展。术语“监督控制”指的是一种控制范式，其中要合成的控制器将禁用某些可能最终导致不可接受的闭环行为的事件，但将允许所有其他事件。参考典型目标应用程序的多组件结构，监督控制器合成中的主要挑战是整体状态集在组件数量方面的指数增长。这是通过组合方法解决的，它避免了整体模型的显式构建。在其基本形式中，DES对事件顺序进行建模，这足以综合保证系统安全运行的监督；例如，在自动运输方面，为了安全起见，一段轨道一次只能由一列火车使用。然而，对于许多应用程序，性能明确地与物理时间相关；例如，就自动运输而言，我们关注的是在所有可用的列车和轨道上实现的整体吞吐量。在这里，文献提供了多种在表达能力上不同的建模框架。在范围的一端，有Brandin-Wonham框架，它使用全局滴答事件来表示时间的流逝，还有时间事件图（TEG），这是一种特定类型的Petri网，可以转换为线性（max, +）方程。对于这两个框架，控制器综合是很容易理解的。然而，由于在表达性方面处于低端，这两个框架都有严重的局限性。在Brandin-Wonham中，不能对具有多个实时时钟的并发系统进行建模，而且TEG不能处理逻辑决策。在本研究项目中，我们将建立比Brandin-Wonham框架和TEG更具表现力的有效方法来控制时间DES。从技术上讲，我们将考虑所谓的（max, +）自动机和特定类别的定时Petri网作为基本模型，以便开发模块化和分层的监督控制方法，包括各自的综合算法。我们的结果将大大扩大基于模型的DES控制器综合的范围。