离散事件动态系统的D－B动机模型

首先引入Ｄ－子集和Ｄ－语言的概念，在此基础上给出了一类离散事件动态系统的一般形式化表述──Ｄ－自动机模型，并讨论了受控系统的动态行为．最后研究了系统的状态可达性问题．     

基于非齐整自动机模型的离散事件系统监控

本文研究了一类不能用齐整自动机建模的离散事件系统的监控问题,首先介绍了自动机齐整性的定义及检测方法，接着给出了将系统分解为若干个子系统的算法，最后讨论了系统监控问题，所得结果具有一定的参考价值。     

实时离散事件动态系统的状态行为与最速控制

基于Ｄ－自动机模型，通过广义状态谓词空间与半范数的概念，深入研究了实时ＤＥＤＳ的状态行为及最速控制问题，最后讨论了此类控制问题解的存在性。     

离散事件动态系统多模型集成控制理论

本文讨论现有各种DEDS模型和理论之间的关系以及建立统一的DEDS理论的可能性问题,主要内容包括:DEDS的复杂性以及对它采用多重模型描述和递阶控制结构的必要性;对现有理论模型和控制问题进行综述以揭示它们作为“知识块”看待时其间的相互联系;集成的方法论和为此目的运用人工智能技术的重要性。     

离散事件动态系统理论的发展动向

离散事件动态系统(DEDS)是这样一类人造系统,它在每一时间点上的变化发展依赖于许多不同事件的复杂交互作用,其状态仅在离散的时间点上发生变化。这样的系统很多,如制造系统、计算机系统、城市交通系统、排队服务系统、复杂的多模式过程控制系统等。离散事件动态系统理论自1980年由美国哈佛大学著名教授何毓琦(Y.C.Ho)倡导研究以来,已取得了不小进展。十多年后的今天,问题和成果并存,我们对建立这一理论的困难也有了进一步的认识。本文从探索的角度向读者简介一下此理论的发展情况,与计算机科学的联系,潜在的应用问题,及讨论一下此理论目前存在的问题和未来发展方向。本文不     

离散事件动态系统稳定性分析方法

本文提出一种受控时序PETRI网络方法以建立离散事件动态系统状态空间模型,并以此为基础给出一类离散事件系统的稳定性定义及一种新的稳定性分析方法.     

“线性”离散事件动态系统的特征值

本文讨论无环向图和皮特利网描述的一类离散事件动态系统的特征值的求解方法，对事件延迟系统，给出了频域的特征矩阵M（z)的特征值求法，并由之提出一个新的求取闭环无环向图描述的离散系统特征值的方法。     

离散事件动态系统的能观性

研究离散事件动态系统的能观性与对偶原理,用极大代数上方程唯一解的引理得到了完全能观性的新判据,由此给出了著名的对偶原理;提出能观维数的新概念,得到了维数对偶原理:并分析了完全能观状态集的结构。     

离散事件动态系统状态空间秒速的进一步研究*

本文对离散事件动态系统的状态空间描述问题作了进一步的研究。指出了原有结果的错误和不足,讨论了既有串行阻塞又有并行阻塞的复杂阻塞现象,建立了适用于一般系统的状态方程。     

线性离散事件动态系统的鲁棒性*

应用极大代数,可对一类离散事件动态系统建立线性模型,本文讨论这类系统的鲁捧性,首先系统地讨论了系统中有一个参数发生摄动时对整个系统动态性能的影响,并对系统参数按照这种影响进行了分类,对于系统中有多个参数同时发生增性摄动的情况,给出了不影响系统动态性能的各个参数的允许摄动范围,亦即鲁棒性条件,这个范围在一定意义下是最大允许的参数摄动范围。     

离散事件动态系统中的控制综合问题

本文将离散事件动态系统（ＤＥＤＳ）监控方法中的控制综合问题作了系统的分类，得到了六种控制综合问题，并将它们表示成泛函极值问题，讨论了它们的可行解，最优解的存在性，可生解集的结构以及相互之间的关系。     

Optimal Control of Two-Stage Discrete Event Systems with Real-Time Constraints

We consider discrete event systems (DES) involving tasks with real-time constraints and seek to control processing times so as to minimize a cost function subject to each task meeting its own constraint. When tasks are processed over a single stage, it has been shown that there are structural properties of the optimal sample path that lead to very efficient solutions of such problems. When tasks are processed over multiple stages and are subject to end-to-end real-time constraints, these properties no longer hold and no obvious extensions are known. We consider a two-stage problem with homogeneous cost functions over all tasks at each stage and derive several new optimality properties. These properties lead to the idea of introducing “virtual” deadlines at the first stage, thus partially decoupling the stages so that the known efficient solutions for single-stage problems can be used. We prove that the solution obtained by an iterative virtual deadline algorithm (VDA) converges to the global optimal solution of the two-stage problem and illustrate the efficiency of the VDA through numerical examples.

Optimal Control of Discrete Event Systems with Weakly Hard Real-Time Constraints

We consider Discrete Event Systems that can dynamically allocate resources in order to process tasks with real-time constraints. In the case of “weakly hard” constraints, a fraction of tasks is allowed to violate them, as long as m out of any k consecutive tasks meet their respective constraints. This is a generalization of a system with purely hard real-time constraints where m = k = 1. For non-preemptive and aperiodic tasks, we formulate an optimization problem where task processing times are controlled so as to minimize a cost function while guaranteeing that a “weakly hard” criterion is satisfied. We establish a number of structural properties of the solution to this problem which lead to an efficient algorithm that does not require any explicit nonlinear programming problem solver. The low complexity of this algorithm makes it suitable for on-line applications. Simulation examples illustrate the performance improvements in such optimally controlled systems compared to ad hoc schemes.

Generalized Detectability for Discrete Event Systems

In our previous work, we investigated detectability of discrete event systems, which is defined as the ability to determine the current and subsequent states of a system based on observation. For different applications, we defined four types of detectabilities: (weak) detectability, strong detectability, (weak) periodic detectability, and strong periodic detectability. In this paper, we extend our results in three aspects. (1) We extend detectability from deterministic systems to nondeterministic systems. Such a generalization is necessary because there are many systems that need to be modeled as nondeterministic discrete event systems. (2) We develop polynomial algorithms to check strong detectability. The previous algorithms are based on an observer whose construction is of exponential complexity, while the new algorithms are based on a new automaton called a detector. (3) We extend detectability to D-detectability. While detectability requires determining the exact state of a system, D-detectability relaxes this requirement by asking only to distinguish certain pairs of states. With these extensions, the theory on detectability of discrete event systems becomes more applicable in solving many practical problems.     

离散事件系统的一种N步在线监控策略

文中给出了离散事件系统的一种N步在线监控策略.其特点是控制策略取决于系统当前运行的N步后继运行投影或预测,无需计算非能控语言的上限能控子语言,通过适当选取N,仍可保证系统的最优运行.同时还给出了与之相关的一些理论结果.