State Estimation and Sensor Selection in Discrete Event Systems Modeled by Petri Nets - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook State Estimation and Sensor Selection in Discrete Event Systems Modeled by Petri Nets write by Yu Ru. This book was released on 2010. State Estimation and Sensor Selection in Discrete Event Systems Modeled by Petri Nets available in PDF, EPUB and Kindle. A discrete event system (DES) is a dynamic system that evolves in accordance with the abrupt occurrence, at possibly unknown and irregular intervals, of physical events. Such systems arise in a variety of contexts, such as energy distribution networks, computer and communication networks, automated manufacturing systems, air traffic control systems, highly integrated command, control, communication, and information (C3I) systems, advanced monitoring and control systems in automobiles or large buildings, intelligent transportation systems, and distributed software systems. Petri net models are widely used for modeling such systems, and consist of two key components: places (which typically model buffers that store system resources) and transitions (which typically model activities that move and process resources across places in the system). Sensors in Petri nets come in two major types: place sensors (i.e., sensors that indicate the number of resources in a particular place, e.g., vision sensors) and transition sensors (i.e., sensors that can detect whether a transition in a given subset of transitions has occurred, e.g., motion sensors). In this dissertation, we focus on two sensor related problems in discrete event systems modeled by Petri nets: (i) State estimation. When only transition sensors are available, sensor information can be very limited because there can be uncertainty due to unobservable events or events that generate the same sensor information. As a result, multiple states could be possible given sensing information, and we show in this dissertation that the number of possible states can grow at most polynomially (but not exponentially) as a function of the length of the observation sequence. These polynomial bounds can guide the design of systems, especially when trying to configure the sensors in order to reduce the uncertainty introduced in the state estimation stage. The polynomial bounds can also be used in analyzing algorithms in the context of state estimation, fault diagnosis, supervisory control, and even reachability checking. (ii) Sensor selection. If there are only transition sensors with uncertainty, the system state is usually not unique. If we have the freedom to configure sensors (e.g., when we design the system), we might want to add a minimal number of sensors to ensure that the current system state can be uniquely reconstructed based on the system model and the initial state. The design consideration is motivated by supervisory control applications, interface design for safety critical systems, and certain fault detection and correction settings. In its most general form, this type of sensor selection problem can involve both place sensors and transition sensors. We study how to choose a minimum number of place sensors and transition sensors (or a set of place sensors and transition sensors of minimal cost) while ensuring that the system state can be determined uniquely given sensing information and knowledge of the system model; this property is called structural observability. We show that the general sensor selection problem is computationally hard. If we are given a fixed set of transition sensors and are interested in selecting place sensors from a given set to achieve structural observability, the problem can be solved optimally by linear integer programming solvers, or suboptimally by heuristic methods we propose. On the other hand, if we have a fixed set of place sensors and then select transition sensors, the problem is solvable with complexity that is polynomial in the number of places and transitions. Among other potential applications, the heuristic methods we propose have implications for sensor selection to achieve immediate diagnosis of faults, reduct calculation in rough set theory, and approximating solutions for other NP-complete problems.
Control of Discrete-Event Systems
Control of Discrete-Event Systems - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Control of Discrete-Event Systems write by Carla Seatzu. This book was released on 2012-07-27. Control of Discrete-Event Systems available in PDF, EPUB and Kindle. Control of Discrete-event Systems provides a survey of the most important topics in the discrete-event systems theory with particular focus on finite-state automata, Petri nets and max-plus algebra. Coverage ranges from introductory material on the basic notions and definitions of discrete-event systems to more recent results. Special attention is given to results on supervisory control, state estimation and fault diagnosis of both centralized and distributed/decentralized systems developed in the framework of the Distributed Supervisory Control of Large Plants (DISC) project. Later parts of the text are devoted to the study of congested systems though fluidization, an over approximation allowing a much more efficient study of observation and control problems of timed Petri nets. Finally, the max-plus algebraic approach to the analysis and control of choice-free systems is also considered. Control of Discrete-event Systems provides an introduction to discrete-event systems for readers that are not familiar with this class of systems, but also provides an introduction to research problems and open issues of current interest to readers already familiar with them. Most of the material in this book has been presented during a Ph.D. school held in Cagliari, Italy, in June 2011.
Introduction to Discrete Event Systems
Introduction to Discrete Event Systems - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Introduction to Discrete Event Systems write by Christos G. Cassandras. This book was released on 2021-11-11. Introduction to Discrete Event Systems available in PDF, EPUB and Kindle. This unique textbook comprehensively introduces the field of discrete event systems, offering a breadth of coverage that makes the material accessible to readers of varied backgrounds. The book emphasizes a unified modeling framework that transcends specific application areas, linking the following topics in a coherent manner: language and automata theory, supervisory control, Petri net theory, Markov chains and queueing theory, discrete-event simulation, and concurrent estimation techniques. Topics and features: detailed treatment of automata and language theory in the context of discrete event systems, including application to state estimation and diagnosis comprehensive coverage of centralized and decentralized supervisory control of partially-observed systems timed models, including timed automata and hybrid automata stochastic models for discrete event systems and controlled Markov chains discrete event simulation an introduction to stochastic hybrid systems sensitivity analysis and optimization of discrete event and hybrid systems new in the third edition: opacity properties, enhanced coverage of supervisory control, overview of latest software tools This proven textbook is essential to advanced-level students and researchers in a variety of disciplines where the study of discrete event systems is relevant: control, communications, computer engineering, computer science, manufacturing engineering, transportation networks, operations research, and industrial engineering. Christos G. Cassandras is Distinguished Professor of Engineering, Professor of Systems Engineering, and Professor of Electrical and Computer Engineering at Boston University. Stéphane Lafortune is Professor of Electrical Engineering and Computer Science at the University of Michigan, Ann Arbor.
Estimation and Inference in Discrete Event Systems
Estimation and Inference in Discrete Event Systems - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Estimation and Inference in Discrete Event Systems write by Christoforos N. Hadjicostis. This book was released on 2019-10-02. Estimation and Inference in Discrete Event Systems available in PDF, EPUB and Kindle. Estimation and Inference in Discrete Event Systems chooses a popular model for emerging automation systems—finite automata under partial observation—and focuses on a comprehensive study of the key problems of state estimation and event inference. The text includes treatment of current, delayed, and initial state estimation. Related applications for assessing and enforcing resiliency—fault detection and diagnosis—and security—privacy and opacity—properties are discussed, enabling the reader to apply these techniques in a variety of emerging applications, among them automated manufacturing processes, intelligent vehicle/highway systems, and autonomous vehicles. The book provides a systematic development of recursive algorithms for state estimation and event inference. The author also deals with the verification of pertinent properties such as: the ability to determine the exact state of a system, “detectability”; the ability to ensure that certain classes of faults can be detected/identified, “diagnosability”; and the ability to ensure that certain internal state variables of the system remain “hidden” from the outside world regardless of the type of activity that is taking place, “opacity”. This book allows students, researchers and practicing engineers alike to grasp basic aspects of state estimation in discrete event systems, aspects like distributivity and probabilistic inference, quickly and without having to master the entire breadth of models that are available in the literature.
Modeling, Monitoring and Optimization of Discrete Event Systems Using Petri Nets
Modeling, Monitoring and Optimization of Discrete Event Systems Using Petri Nets - read free eBook in online reader or directly download on the web page. Select files or add your book in reader. Download and read online ebook Modeling, Monitoring and Optimization of Discrete Event Systems Using Petri Nets write by Jiaxiang Yan. This book was released on 2013. Modeling, Monitoring and Optimization of Discrete Event Systems Using Petri Nets available in PDF, EPUB and Kindle. In last decades, the research of discrete event systems (DESs) has attracts more and more attention because of the fast development of intelligent control strategies. Such control measures combine the conventional control strategies with discrete decision-making processes which simulate human decision-making processes. Due to the scale and complexity of common DESs, the dedicated models, monitoring methods and optimal control strategies for them are necessary. Among various DES models, Petri nets are famous for the advantage in dealing with asynchronous processes. They have been widely applied in intelligent transportation systems (ITS) and communication technology in recent years. With encoding of the Petri net state, we can also enable fault detection and identification capability in DESs and mitigate potential human errors. This thesis studies various problems in the context of DESs that can be modeled by Petri nets. In particular, we focus on systematic modeling, asynchronous monitoring and optimal control strategies design of Petri nets. This thesis starts by looking at the systematic modeling of ITS. A microscopic model of signalized intersection and its two-layer timed Petri net representation is proposed in this thesis, where the first layer is the representation of the intersection and the second layer is the representation of the traffic light system. Deterministic and stochastic transitions are both involved in such Petri net representation. The detailed operation process of such Petri net representation is stated. The improvement of such Petri net representation is also provided with comparison to previous models. Then we study the asynchronous monitoring of sensor networks. An event sequence reconstruction algorithm for a given sensor network based on asynchronous observations of its state changes is proposed in this thesis. We assume that the sensor network is modeled as a Petri net and the asynchronous observations are in the form of state (token) changes at different places in the Petri net. More specifically, the observed sequences of state changes are provided by local sensors and are asynchronous, i.e., they only contain partial information about the ordering of the state changes that occur. We propose an approach that is able to partition the given net into several subnets and reconstruct the event sequence for each subnet. Then we develop an algorithm that is able to reconstruct the event sequences for the entire net that are consistent with: 1) the asynchronous observations of state changes; 2) the event sequences of each subnet; and 3) the structure of the given Petri net. We discuss the algorithmic complexity. The final problem studied in this thesis is the optimal design method of Petri net controllers with fault-tolerant ability. In particular, we consider multiple faults detection and identification in Petri nets that have state machine structures (i.e., every transition in the net has only one input place and one output place). We develop the approximation algorithms to design the fault-tolerant Petri net controller which achieves the minimal number of connections with the original controller. A design example for an automated guided vehicle (AGV) system is also provided to illustrate our approaches.
