判定非确定离散事件系统稳定性的梯度搜索算法

讨论基于非确定自动机/形式语言模型的非确定离散事件系统(NDES)稳定性问题.引入非确定离散事件系统稳定性的定义,并得到了稳定性的判据定理.给出了基于梯度的搜索算法,该算法可有效消除观测器的冗余,从而降低了计算复杂度.     

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。     

离散事件系统的学习控制初探

本文建立了包含状态持续时间的离散事件系统的自动机模型，然后引入学习算法用以确定描述闭环系统进行了语言K,从而当控制指标是以时间形式给出时，仍能利用监控理论来设计散事件系统。     

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。     

离散事件系统不透明性监督控制研究综述

离散事件系统不透明性是指外部观察者无法分辨系统的一系列行为是否为系统所发生的.而离散事件不透明性监督控制则是构建监督器控制系统行为,使系统满足不透明性的一种方法.离散事件系统不透明性与信息安全有着紧密的联系,并得到了广泛的应用.首先对离散事件系统做了简要的概述,然后介绍了不透明性监督控制算法的研究现状,最后进行了总结和展望.     

基于规则的模糊离散事件系统建模与控制研究

用模糊离散事件系统（FDES）从离散事件的角度描述一类包含“具有确定性的不确定／模糊”问题以及与人的主观观察／判断密切相关的复杂系统。提出了基于规则的FDES描述方法及自寻优监督控制策略,为FDES的实际应用提供了一种方法,提高了FDES在具体应用中的可操作性,并介绍了其在纺织染整控制过程中的具体应用．     

一种新的离散事件系统控制方案

给定离散事件系统（ＤＥＳ）Ｇ及某个规定的最大允许合法语言文明（ＭＰＬＬＳ）Ｋ，监督控制在任务就是寻找一个监控器Ｓ，使得系统在监控下不会突破该ＭＰＬＬＳ，也即满足：Ｌ（Ｓ／Ｇ）包含于Ｋ，传统的实现方法要求给定ＭＰＬＩＳＫ计算其最大可控子语言Ｋ＾↑因此难免显示地构造Ｓ。本文给了一种新的方案可以不必对Ｋ＾↑和Ｓ作显式计算，监控任务是随ＤＥＳＧ的演化结合规定的ＭＰＬＬＳＫ用动态方法实现，该方案在很大程度上     

对称离散事件系统事件重标记观测器性质研究

当离散事件系统(discrete-event systems,DES)由多组结构相同的组件构成时,则称离散事件系统具有对称性.为了化简对称离散事件系统的状态空间,本文提出事件重标记映射,将完成相同任务的事件标记为同一事件,将与控制无关的不可控事件设为不可观测事件,并将其标记为空字符擦除.为了确保事件重标记前后系统对应的最大监督控制器具有相同的控制效果,本文引入重标记观测器(relabeling observer property,ROP)的概念并给出判断被控对象对应的语言关于事件重标记映射是否具有重标记观测器性质的算法;然后运用重标记观测器性质证明事件重标记前后监督控制器控制效果的等价性,从而可用简化后的监督控制器实现与事件重标记操作前相同的控制任务.最后通过实例验证所提理论的正确性.     

不确定离散时滞系统的时滞相关非脆弱H_∞控制

讨论不确定离散时滞系统非脆弱控制器的设计问题.利用Lyapunov-Krasovskii稳定性理论和有限和不等式方法,获得了不确定时滞系统在非脆弱控制器作用下不仅内部渐近稳定,而且具有给定的H∞扰动抑制水平y的时滞相关有界实条件.采用迭代算法分别给出了控制器具有加法不确定性和乘法不确定性两种情况的非脆弱控制器参数的设计方法,借助于Matlab的LMI工具箱可以方便求解.数值仿真实例表明了该方法的有效性.     

Supervisory control of discrete event systems with state-dependent controllability

This article studies the supervisory control problem of discrete event systems (DES) with state-dependent controllability. The new problem is given with the background of operating systems where the processes and the interrupt service routines (ISR) are supervised and coordinated. The new model is novel because the controllability of an event is changeable in the lifetime of system evolution, and dependent on the system state. Two fundamental problems are concerned with the new model: supervisor existence problem and supervisor synthesis problem. We derive a necessary and sufficient condition for the existence of the supervisor, and introduce an algorithm to synthesise the supremal supervisor in a given specification. With the background of process and ISR management in operating systems, some examples are given to show how the new model can be applied to practical computing.     

基于不确定观测下离散事件系统可诊断性的研究

在实际应用系统中,由于传感器故障、传感器限制和网络中的数据包丢失等原因,事件的可观测值变得不确定,使得观测系统行为变得尤为复杂。针对离散事件系统中,同个事件串可能有多个观测值以及不同状态下同个事件观测值也可能不同的问题,提出一种不确定观测下故障诊断验证的方法。首先对不确定观测的离散事件系统的可诊断性进行形式化,然后构建出用于上述故障诊断验证的验证器;基于验证器提出了系统基于不确定观测下可诊断的充要条件及验证算法;最后,实例说明不确定观测下故障诊断验证算法的应用。与现有研究相比,提出的方法对故障事件的观测值没有约束,可以为0个或多个观测值,使此方法应用的场景更为广泛。     

On-line control of partially observed discrete event systems

It is well known that the design of supervisors for partially observed discrete-event systems is an NP-complete problem and hence computationally impractical. Furthermore, optimal supervisors for partially observed systems do not generally exist. Hence, the best supervisors that can be designed directly for operation under partial observation are the ones that generate the supremal normal (and controllable) sublanguage. In the present paper we show that a standard procedure exists by which any supervisor that has been designed for operation under full observation, can be modified to operate under partial observation. When the procedure is used to modify the optimal full-observation supervisor (i.e., the one that generates the supremal controllable language), the resultant modified supervisor is at least as efficient as the best one that can be designed directly (that generates the supremal normal sublanguage). The supervisor modification algorithm can be carried out on-line with linear computational complexity and hence makes the control under partial observation a computationally feasible procedure.     

离散事件系统的混合分散监控

研究了混合信息下的分散监控综合问题.首先提出δ-可观察(hδ-可观察)可控闭语言是(状态部分可观察下)状态反馈综合解存在的充要条件,并由此得到n-联合可观察、可控闭的系统约束是保证混合分散监控器存在的充要条件,进而得到纯分散监控器(控制器)存在的充要条件为n-可观察(n-hδ-可观察)可控闭语言被满足.最后,又通过研究系统约束与混合约束的关系,提出混合分散监控器存在的充分条件是可观察、可控闭语言与可观察可控谓词被满足.     

Bisimilarity control of partially observed nondeterministic discrete event systems and a test algorithm

In this paper, the bisimilarity control of discrete event systems (DESs) under partial observations is investigated, where the plant and the specification are allowed to be nondeterministic. A notation of simulation-based controllability and a synchronization scheme for the supervised system are formalized based on the simulation relation between the specification and the plant. It is shown that the existence of bisimilarity supervisors is characterized by the notions of the simulation-based controllability and the language observability, which extends the traditional results of supervisory control from language equivalence to bisimulation equivalence. In addition, a polynomial algorithm to test the simulation-based controllability is developed by constructing a computing tree. This algorithm together with the test of language observability can be used to check the existence of bisimilarity supervisors.     

Decentralized supervisory control of nondeterministic discrete event systems: The existence condition of a robust and nonblocking supervisor

This paper addresses a decentralized supervisory control problem for an uncertain discrete event system (DES) modeled by a set of possible nondeterministic automata with unidentified internal events. For a given language specification, we present the existence condition of a robust and nonblocking decentralized supervisor that achieves this specification for any nondeterministic model in the set. In particular, we show that the given language specification can be achieved based on the properties of its controllability and coobservability with respect to the overall nominal behavior of the uncertain DES. It is further shown that the existence of a nonblocking decentralized supervisor can be examined with a trajectory model of the language specification.     

一类离散事件系统的监控器综合

前向无同步前向无冲突网是每个变迁有且只有一个输入库所并且每个库所最多有一个输入变迁的受限Petri网.针对不可控影响子网为前向无同步前向无冲突网的广义互斥约束,显式地给出了最大允许控制策略的计算方法.并用一个例子给予了说明.     

离散事件系统的混合可靠分散监控

在研究基于混合信息的分散监控时,由于部分监控器与部分控制器发生失败,故提出了一种新型的混合可靠分散监控问题.通过修改局部可控事件集与不可控事件集,提出新的可控语言与可靠联合可观察语言定义,进而得到混合可靠分散监控器存在的充分必要条件就是整体约束语言是可靠联合可观察,可控闭的.之后,又通过研究整体约束与混合子约束之间的关系,给出了判别混合可靠分散监控器存在的一个充分条件,即混合子约束分别满足基于谓词的可观察,可控性与基于语言的联合可观察,可控封闭性.     

On tolerable and desirable behaviors in supervisory control of discrete event systems

We formulate and solve a new supervisory control problem for discrete event systems. The objective is to design a logical controller—or supervisor—such that the discrete event system satisfies a given set of requirements that involve event ordering. The controller must deal with a limited amount of controllability in the form of uncontrollable events. Our problem formulation considers that the requirements for the behavior (i.e., set of traces) of the controlled system are specified in terms of a desired behavior and a larger tolerated behavior. Due to the uncontrollable events, one may wish to tolerate behavior that sometimes exceeds the ideal desired behavior if overall this results in achieving more of the desired behavior. The general solution of our problem is completely characterized. The nonblocking solution is also analyzed in detail. This solution requires the study of a new class of controllable languages. Several results are proved about this class of languages. Algorithms to compute certain languages of interest within this class are also presented.Research supported in part by the National Science Foundation under grants ECS-8707671, ECS-9057967, and ECS-9008947.