基于Petri网的非线性多变量系统解耦控制

广义自控网系统是一类弧权值受库所控制的高级Petri网,能够简单有效地建模PID控制规律.借鉴单神经元PID控制原理,在广义自控网系统的基础上加入神经元网络的学习规则,设计基于广义自控网系统的PID控制器,并用于非线性多变量系统解耦控制.所提方法充分利用了自控网系统的特点,所设计的控制器模型能实现系统控制与参数学习的统一.结合双容水箱控制系统实例进行仿真分析,分析结果验证了所提方法的有效性.     

线性定常系统的输入-输出能量解耦

提出一种介于动态解耦与静态解耦之间的能量解耦方法, 即从输入_输出的能量关系上实现解耦, 使得任何一个输入的能量主要控制对应的一个输出的能量, 对其它输出能量的影响尽可能小. 所给实例表明, 该方法具有良好的解耦效果.     

线性定常系统的输入-输出能量解耦

提出一种介于动态解耦与静态解耦之间的能量解耦方法,即从输入_输出的能量关系上实现解耦,使得任何一个输入的能量主要控制对应的一个输出的能量,对其它输出能量的影响尽可能小.所给实例表明,该方法具有良好的解耦效果.     

一类Petri网系统的活性

Petri网是一种用来研究具有异步、并发特征的离散事件系统的合适的工具，当用Petri网来模拟一个实际系统时，关心的问题之一就是要确定这个Petri网模型是否具有一些所期望的特生，如活性、有界性等，这些特性均是系统的重要动态行为，该文基于文献[1]给出了Petri网的一子类，即弱化非自控网（Weak Extended Non SelfControlling Nets,简称WENSeC网），该类网覆盖了扩展自由选择网和扩展非自控网，文中提出了并证明了WENSeC网系统活性的的充分必要条件满足死锁－陷阱性质，同时对WENSeC网的一子类，通过转化方法，证明了该类结构有界网的结构活判定算法可借用扩非自控网的有关结果也是多项式时间算法。     

线性连续定常系统状态比例积分反馈控制

在状态反馈控制的基础上,提出了状态比例积分反馈控制的理论,并证明了线性定常系统状态比例积分反馈控制系统的能控性、能观性和稳定性的充分条件。     

关于线性定常大系统的局部控制与状态估计

本文给出了一类线性定常大系统可局部镇定的充要条件。对一类较广的可局部镇定的大系统,本文证明它们是可以任置稳定度的。文中还得到了大系统存在分散观测器及分散控制的充要条件。所有证明都是构造性的。     

线性逻辑,Petri网和并发计算

1.线性逻辑和张量理论在古典逻辑的 Gentzen 型矢列演算中Girard 去除弱规则和缩规则,发展起一种新型逻辑系统——线性逻辑(简记为 LL)。它不同于古典逻辑,本质上是一种事态逻辑(logic of situation),或者是一动作逻辑(logic of action),强调系统的动态特征与并发计算紧密相关。结构规则的去除自然在 LL 中导致了两种类型的连接词:乘性连接词和加性连接词,     

线性定常系统仿真的两种新算法

本文提出了两种适合于对线性定常系统进行仿真的新算法,它们不仅保持了改进转移矩阵法和拟Adams法的A-稳定性、计算量较小和精度较高等优点,而且弥补了这两种方法在理论上的不严密性和截断误差较大等缺陷,因而具有更好的数值特性,仿真结果表明,文中提出的算法是有效可行的。     

Petri网性质的线性时序逻辑描述与Spin检验

Petri网是描述并发系统的很直观的图形工具Spin是一种著名的分析验证并发系统性质的工具。本文首先论述Petri网性质的线性时序逻辑描述，研究用Promela编程描述Petri网和用Spin对Petri网性质进行检验的方法，最后通过两个具体的示例说明这种方法是成功的。     

Feasibility of piecewise-constant control sequences for timed continuous Petri nets

In this study, the determination of control actions for timed continuous Petri nets is investigated by the characterisation of attractive regions in marking space. In particular, attraction in finite time, which is important for practical issues, is considered. Based on the characterisation of attractive regions, the domain of admissible piecewise constant control actions is computed, and sufficient conditions to verify the feasibility of the control objectives are proposed. As a consequence, an iterative procedure is presented to compute piecewise constant control actions that correspond to local minimum time control for timed continuous Petri nets.     

Decomposition of first-order hybrid Petri nets for hierarchical control of manufacturing systems

Although hybrid Petri net (HPN) is a popular formalism in modelling hybrid production systems, the HPN model of large scale systems gets substantially complicated for analysis and control due to large dimensionality of such systems. To overcome this problem, a typical approach is to decompose the net into subnets and then control the plant through hierarchical or decentralized structures. Although this concept has been widely discussed in the literature for discrete PNs, there is a lack of research for HPNs. In this paper, a new method of decomposition of first-order hybrid Petri nets (FOHPNs) is proposed first and then the hierarchical control of the subnets through a coordinator is introduced. The advantage of using the proposed approach is validated by an existing example. A sugar milling case study is analysed by using a decomposed FOHPN model and the optimization results are compared against the results of the approaches presented in other papers. Simulation results show not only an improvement in production rate, but also show the ability to control the plant online. In addition, by using the hierarchical control structure for an FOHPN model, it is possible to reduce the cost of communication links, improve the reliability of the system, maintain the plant locally, and partially redesign the system.     

Verifying time Petri nets by linear programming

The paper proposes an approach to solving some verification problems of time petri nets using linear programming.The approach is based on the observation that for loop-closed time Ptri nets,it is only necessary to investigate a finite prefix of an untimed run of the underlying Petri net.Using the technique the paper gives solutions to reachabiltiy and bounded delay timing analysis problems.For both problems algorithms are given,that are decision procedures for loop-closed time Petri nets.and semi-decision procedures for general time Petri nets.     

Real-time scheduling of batch systems using Petri nets and linear logic

This paper presents an approach to model, design and verify scenarios of real-time systems used in the scheduling and global coordination of batch systems. The initial requirements of a system specified with sequence diagrams are translated into a single p-time Petri net model representing the global behavior of the system. For the Petri net fragments involved in conflicts, symbolic production and consumption dates assigned to tokens are calculated based on the sequent calculus of linear logic. These dates are then used for off-line conflict resolution within a token player algorithm used for scenario verification of real-time specifications and which can be seen as a simulation tool for UML interaction diagrams.     

基于DISCOVERER的Petri网不变式自动生成

在Petri网的验证中,代数不变式起着非常重要的作用。将Petri网建模为半代数变迁系统,提出了自动生成不变式的算法,该不变式有助于更好地分析Petri网可达空间。算法首先将Petri网的不变式假定为一个含参数系统,然后通过求解半代数系统来求解不变式中的参数;最后,基于DISCOVERER和QEPCAD等Maple软件包实现了该算法,并通过实例说明了算法的有效性。     

Multiobjective scheduling algorithm for flexible manufacturing systems with Petri nets

In this work, we focus on general multi-objective scheduling problems that can be modeled using a Petri net framework. Due to their generality, Petri nets are a useful abstraction that captures multiple characteristics of real-life processes.To provide a general solution procedure for the abstraction, we propose three alternative approaches using an indirect scheme to represent the solution: (1) a genetic algorithm that combines two objectives through a weighted fitness function, (2) a non dominated sorting genetic algorithm (NSGA-II) that explicitly addresses the multi-objective nature of the problem and (3) a multi-objective local search approach that simultaneously explores multiple candidate solutions. These algorithms are tested in an extensive computational experiment showing the applicability of this general framework to obtain quality solutions.     

基于资源配置混杂Petri网的混杂系统生产过程建模

为了增强混杂Ｐｅｔｒｉ网解决资源共享和资源冲突的能力,定义一种新的混杂Ｐｅｔｒｉ网模型———资源配置混杂Ｐｅｔｒｉ网,提出了相应的使能和激发规则．将对连续变迁和离散变迁的控制作用引入混杂Ｐｅｔｒｉ网,同时,增加了资源配置变迁和资源释放变迁,用于有效分配可重复利用的资源．以典型的混杂生产过程为例,研究混杂系统生产过程建模．研究结果表明,所定义的模型描述能力强,模型语义正确合理,能够有效描述和分析混杂系统生产过程．     

Structural optimal control for safe Petri nets

This article addresses the problem of forbidden states in both conservative and non-conservative safe Petri net (PN) models. The property of conservativeness is discussed, and its implications are analysed. The construction and formulation of control conditions in the context of safe and non-conservative PN models is investigated, emphasising the problem of control optimality. The fundamental issue studied is that of the equivalence between a forbidden state and its associated constraint. A new fashion of writing control conditions is proposed and used, in conjunction with the place-invariant synthesis method, for the generation of a control solution. The final controlled model obtained is a PN similar in size to the initial model. Finally, the approach is illustrated via a simple example.     

基于一阶混杂Petri网的柔性制造系统粗糙控制

研究基于一阶混杂Petri网模型的柔性制造系统粗糙控制.为构造正确的一阶混杂Petri网模型行为演变图,提出了确定改变Macro状态事件的新方法;进而给出了柔性制造系统优化与控制算法,并基于粗糙集合理论和所给出的算法,提出了柔性制造系统的粗糙控制方法.最后通过一个实例验证了该方法的有效性.