Showing papers in "IEEE Control Systems Magazine in 2015"

Physical Authentication of Control Systems: Designing Watermarked Control Inputs to Detect Counterfeit Sensor Outputs

Abstract: Cyberphysical systems (CPSs) refer to the embedding of widespread sensing, networking, computation, and control into physical spaces with the goal of making them safer, more efficient, and reliable. Driven by the miniaturization and integration of sensing, communication, and computation in cost-efficient devices, CPSs are bound to transform industries such as aerospace, transportation, built environments, energy, health care, and manufacturing, to name a few. This great opportunity, unfortunately, is matched by even greater challenges. Taming the complexity of design and analysis of these systems poses a fundamental problem as a new paradigm is needed to bridge various scientific domains, which, through the years, have developed significantly different formalisms and methodologies. In addition, while the use of dedicated communication networks has so far sheltered systems from the outside world, use of off-the-shelf networking and computing, combined with the unattended operation of a plethora of devices, provides several opportunities for malicious entities to inject attacks on CPSs. A wide variety of motivations exists for launching an attack on CPSs, ranging from economic reasons, such as obtaining a financial gain, all the way to terrorism, for instance, threatening an entire population by manipulating life-critical resources. Any attack on safety-critical CPSs may significantly hamper the economy and lead to the loss of human lives. While the threat of attacks on CPSs tends to be underplayed at times, the Stuxnet worm provided a clear example of the possible future to come. This malware, targeting a uranium enriching facility in Iran, managed to reach the supervisory control and data acquisition (SCADA) system controlling the centrifuges used in the enrichment process. Stuxnet modified the control system, increasing pressure in the centrifuges in a first version of the worm and spinning centrifuges in an erratic fashion in a second version. As a result, Stuxnet caused significant damage to the plant [1]. For details, see "The Stuxnet Attack."

Game-Theoretic Methods for Robustness, Security, and Resilience of Cyberphysical Control Systems: Games-in-Games Principle for Optimal Cross-Layer Resilient Control Systems

Abstract: Critical infrastructures, such as power grids and transportation systems, are increasingly using open networks for operation. The use of open networks poses many challenges for control systems. The classical design of control systems takes into account modeling uncertainties as well as physical disturbances, providing a multitude of control design methods such as robust control, adaptive control, and stochastic control. With the growing level of integration of control systems with new information technologies, modern control systems face uncertainties not only from the physical world but also from the cybercomponents of the system. The vulnerabilities of the software deployed in the new control system infrastructure will expose the control system to many potential risks and threats from attackers. Exploitation of these vulnerabilities can lead to severe damage as has been reported in various news outlets [1], [2]. More recently, it has been reported in [3] and [4] that a computer worm, Stuxnet, was spread to target Siemens supervisory control and data acquisition (SCADA) systems that are configured to control and monitor specific industrial processes.

Control-Theoretic Methods for Cyberphysical Security: Geometric Principles for Optimal Cross-Layer Resilient Control Systems

Abstract: Cyberphysical systems integrate physical processes, computational resources, and communication capabilities. Cyberphysical systems have permeated modern society, becoming prevalent in many domains, including energy production, health care, and telecommunications. Examples of cyberphysical systems include sensor networks, industrial automation systems, and critical infrastructures such as transportation networks, power generation and distribution networks, water and gas distribution networks, and advanced manufacturing systems. The integration of cybertechnologies with physical processes increases system efficiencies and, at the same time, introduces vulnerabilities that undermine the reliability of critical infrastructures. As recently highlighted by the Maroochy water breach in March 2000 [1], multiple recent power blackouts in Brazil [2], the SQL Slammer worm attack on the Davis-Besse nuclear plant in January 2003 [3], the StuxNet computer worm in June 2010 [4], and various industrial security incidents [5], cyberphysical systems are prone to failures and attacks on their physical infrastructure and cyberattacks on their data management and communication layer [6], [7].

Heavy-Duty Vehicle Platooning for Sustainable Freight Transportation: A Cooperative Method to Enhance Safety and Efficiency

Abstract: The current system of global trade is largely based on transportation and communication technology from the 20th century. Advances in technology have led to an increasingly interconnected global market and reduced the costs of moving goods, people, and technology around the world [1]. Transportation is crucial to society, and the demand for transportation is strongly linked to economic development. Specifically, road transportation is essential since about 60% of all surface freight transportation (which includes road and rail transport) is done on roads [2]. Despite the important role of road freight transportation in the economy, it is facing serious challenges, such as those posed by increasing fuel prices and the need to reduce greenhouse gas emissions. On the other hand, the integration of information and communication technologies to transportation systems-leading to intelligent transportation systems-enables the development of cooperative methods to enhance the safety and energy efficiency of transportation networks. This article focuses on one such cooperative approach, which is known as platooning. The formation of a group of heavy-duty vehicles (HDVs) at close intervehicular distances, known as a platoon (see Figure 1) increases the fuel efficiency of the group by reducing the overall air drag. The safe operation of such platoons requires the automatic control of the velocity of the platoon vehicles as well as their intervehicular distance. Existing work on platooning has focused on the design of controllers for these longitudinal dynamics, in which simple vehicle models are typically exploited and perfect environmental conditions, such as flat roads, are generally assumed. The broader perspective of how platooning can be effectively exploited in a freight transportation system has received less attention. Moreover, experimental validations of the fuel-saving potential offered by platooning have typically been performed by reproducing the perfect conditions as assumed in the design of the automatic controllers. This article focuses on these two aspects by addressing the following two objectives.

Optimal Ecodriving Control: Energy-Efficient Driving of Road Vehicles as an Optimal Control Problem

Abstract: Transportation is responsible for a substantial fraction of worldwide energy consumption and greenhouse gas emissions and is the largest sector after energy production. However, while emissions from other sectors are generally decreasing, those from transportation have increased since 1990. Reducing the impact of transportation is a task that is inherently associated with the improvement of energy efficiency, particularly for passenger cars that contribute to almost half of the whole sector.

Cyberphysical Security in Networked Control Systems: An Introduction to the Issue

Abstract: This special issue provides an introduction to cyberphysical security of networked control systems (NCSs) and summarizes recent progress in applying fundamentals of systems theory and decision sciences to this new and increasingly promising area. NCS applications range from large-scale industrial applications to critical infrastructures such as water, transportation, and electricity networks. The security of NCSs naturally depends on the integration of cyber and physical dynamics and on different ways in which they are affected by the actions of human decision makers. Thus, problems in this area lie at the intersection of control systems and computer security. The six articles that constitute this special issue approach cyberphysical security from a variety of perspectives, including control theory, optimization, and game theory. They cover a range of topics such as models of attack and defense, risk assessment, his special issue provides an introduction to cyberphysical security of networked control systems (NCSs) and summarizes recent progress in applying fundamentals of systems theory and decision sciences to this new and increasingly promising area. NCS applications range from large-scale industrial applications to critical infrastructures such as water, transportation, and electricity networks. The security of NCSs naturally depends on the integration of cyber and physical dynamics and on different ways in which they are affected by the actions of human decision makers. Thus, problems in this area lie at the intersection of control systems and computer security. The six articles that constitute this special issue approach cyberphysical security from a variety of perspectives, including control theory, optimization, and game theory. They cover a range of topics such as models of attack and defense, risk assessment,attack detection and identification, and secure control design.A common theme among these contributions is an emphasis on the development of a principled approach to cyberphysical security of NCS.

Secure Control Systems: A Quantitative Risk Management Approach

Abstract: Critical infrastructures must continuously operate safely and reliably, despite a variety of potential system disturbances. Given their strict operating requirements, such systems are automated and controlled in real time by several digital controllers receiving measurements from sensors and transmitting control signals to actuators. Since these physical systems are often spatially distributed, there is a need for information technology (IT) infrastructures enabling the timely data flow between the system components. These networked control systems are ubiquitous in modern societies [1]. Examples include the electric power network, intelligent transport systems, and industrial processes.

Covert Misappropriation of Networked Control Systems: Presenting a Feedback Structure

Abstract: The increasing availability of Internet connectivity and networked actuation and sensing components has supported the growth in control systems operated over public networks. Controllers and plants no longer need to be physically colocated as measurements and actuation signals can be sent digitally. Supervisory systems can monitor and control geographically widespread components. However, such systems are now exposed to the risk of remote interference. A feedback structure that allows an attacker to take over control of the plant while remaining hidden from the control and supervisory system(s) is presented. The objective is not to facilitate such attacks but rather to make clear the degree to which the takeover of plant control can be hidden when a sophisticated attacker has some plant knowledge and signal intervention capabilities.

The Problem of Social Control and Coordination of Complex Systems in Sociology: A Look at the Community Cleavage Problem

Abstract: The coordination and control of social systems is the foundational problem of sociology. The discipline was established in Europe in the aftermath of the American and French Revolutions. With the dismantling of the hierarchical controls of European aristocratic systems, the examination of alternative mechanisms of coordination and control became a preoccupation. The Industrial Revolution (c. 1760-1840), which was occurring at the same time, reinforced this preoccupation by decoupling the power of purse and the power of positions of authority. While the hierarchies of church and state retained coercive power, the exercise of such power was increasingly contested. The moral compass of society, its general welfare, and its capacity to adapt to changing circumstances appeared to be aggregated properties of the unconstrained opinions and behaviors of a large collectivity of individuals. The definition of the problem of coordination and control, which emerged in Europe in the new discipline of sociology, still resonates and guides current sociological work. The problem definition [1], broadly stated, is this: if value is placed on nonhierarchical mechanisms of social control, then what mechanisms and structures (consistent with this value) allow a coordination and control of social systems?

Game-Theoretic Models of Electricity Theft Detection in Smart Utility Networks: Providing New Capabilities with Advanced Metering Infrastructure

Abstract: The smart grid refers to the modernization of the power grid infrastructure with new technologies, enabling a more intelligently networked automated system with the goal of improving efficiency, reliability, and security, while providing more transparency and choices to electricity customers. A key technology being widely deployed on the consumption side of the grid is advanced metering infrastructure (AMI).

Human Supervisory Control of Robotic Teams: Integrating Cognitive Modeling with Engineering Design

Abstract: The emergence of sensor networks operating at different modalities, mobility, and coverage has opened the door to systems involving diverse data sources and analysis tools. These complex systems often contain both human and robotic elements, and, in many cases, it is the job of humans to process information generated by autonomous agents [1], [2]. The incredible amount of data generated by modern sensors makes these human operators susceptible to information overload, which can have detrimental effects on performance and may lead to dire consequences [3]. To alleviate this loss in performance, programs like the recent National Robotic Initiative [4] emphasize collaboration between humans and their robotic partners and envision symbiotic mechanisms to facilitate interactions between diverse system components.

Faster, Higher, and Greener: Vehicular Optimal Control

Abstract: Vehicular optimal control problems have been studied extensively since the early part of the 20th century. Progress in solving these problems has been driven primarily by applications in space and atmospheric flight, including launch vehicles, Earth-based and interplanetary space orbital transfer, and high-performance supersonic aircraft. In all of these applications, the ability to solve increasingly complex optimal control problems has been made possible by advances in high-speed computing. The mathematical and computing techniques being developed are now so diverse, and the range of applications of optimal control so broad, that a comprehensive review of the entire scope of vehicular optimal control is an impossible task. Instead, we will attempt only to provide a flavor of the scope and variety of these problems.

Grenoble Traffic Lab: An Experimental Platform for Advanced Traffic Monitoring and Forecasting [Applications of Control]

Abstract: The start from the Ocean House was something marvelous to see. The drivers stormed and scolded, the women shrieked and cried, wheels locked at intervals of perhaps ten minutes. Occasionally, too, a carriage would capsize, and be hauled over to the fence for repairs . . . [It was] like a huge funeral procession, crawling along at a snail's pace. It was a feat to get to the city at all.

Thermoacoustics and the Rijke Tube: Experiments, Identification, and Modeling

Abstract: The Rijke tube [1] is a classic experiment that is relatively simple and inexpensive to build in a typical university laboratory. Despite its construction simplicity, it can serve to illustrate a wide variety of mathematical modeling, empirical identification, verification, and feedback control techniques. As such, it is suitable for use in both advanced undergraduate and graduate control laboratory courses.

Human-in-the-Loop Model Predictive Control of an Irrigation Canal [Applications of Control]

Abstract: Until now, advanced model-based control techniques have been predominantly employed to control problems that are relatively straightforward to model. Many systems with complex dynamics or containing sophisticated sensing and actuation elements can be controlled if the corresponding mathematical models are available, even if there is uncertainty in this information. Consequently, the application of model-based control strategies has flourished in numerous areas, including industrial applications [1]-[3].

A Survey of Elevator Group Control Systems for Vertical Transportation: A Look at Recent Literature

Abstract: Elevators (also called "lifts" in some locales) are installed in buildings to meet the vertical transportation needs of the building occupants. The total vertical transport capacity of a building is a crucial factor in its success as a working, living, or service facility. Elevators must be easily accessible, readily available, provide quality service, and be reliable.

Infinite-Horizon Linear-Quadratic Control by Forward Propagation of the Differential Riccati Equation [Lecture Notes]

Abstract: One of the foundational principles of optimal control theory is that optimal control laws are propagated backward in time. For linear-quadratic control, this means that the solution of the Riccati equation must be obtained from backward integration from a final-time condition. These features are a direct consequence of the transversality conditions of optimal control, which imply that a free final state corresponds to a fixed final adjoint state [1], [2]. In addition, the principle of dynamic programming and the associated Hamilton-Jacobi-Bellman equation is an inherently backward-propagating methodology [3].

Full- and Reduced-Order Linear Observer Implementations in Matlab\/Simulink [Lecture Notes]

Abstract: The design of observers is usually considered a graduate-level topic and therefore tends to be taught in a graduate-level control engineering course. However, several recent editions of standard undergraduate controlsystem textbooks cover full-order, and even reduced-order, observers [1]-[9]. Observers are also used in their own right to strictly observe the state variables of a dynamic system rather than to be used for feedback control (for example, in an experiment whose state variables have to be monitored, observed, or estimated at all times).

Disturbance Observer-Based Control: Methods and Applications [Bookshelf]

Abstract: This 340-page book is primarily based on the authors??? extensive ten-year research effort on disturbance-observer-based control (DOBC) theory and applications. The book covers the theoretical analysis of both basic and advanced concepts in DOBC, as well as engineering applications in process control, mechatronics, and flight control systems. The target audience is both researchers working on advanced control methods and related engineering fields and practicing engineers interested in disturbance estimation and compensation. This book attempts to fill the absence of an academic reference book on DOBC methods and applications, and, in this context, the authors provide a systematic perspective on the underlying philosophy of DOBC, its distinct features relative to other methodologies and design tools, and its major theoretical developments and application-related contributions. An ever-increasing demand for higher-precision control performance has been observed in the modern control systems community, such as in mechatronics and robotics, electrical machines and drives, power electronics, energy conversion, and the aerospace and automotive sectors. DOBC has been known as one of the most promising and effective methods in the control community for quite a long time. While there are many research papers, few academic books exist on the subject, and the authors attempt to fill this void. The book is well written and clearly illustrates the contributions of DOBC alongside established techniques in disturbance rejection. All theoretical results are given with rigorous mathematical proofs. In the applications sections, the simulation results are elegantly presented with plenty of comparative studies. Although most of the mathematical concepts and abbreviations are defined throughout the book, a glossary or list of symbols and abbreviations would be a welcome addition. The book would be a useful resource for an advanced graduate course in control, for researchers in the ar- as of systems and control, as well as an educational reference for practicing engineers.

Spacecraft Dynamics and Control: An Introduction [Bookshelf]

Abstract: This book consists of 26 chapters and two appendices. The exposition is divided into roughly five parts: Basic kinematics and dynamics of particles and rigid bodies; Orbital mechanics of point mass objects; Spacecraft attitude dynamics; Feedback control theory; and Pactical applications of the above four to spacecraft control. This book can be considered as a prequel to those wishing to study the more advanced graduate-level text of Hughes. Overall, I consider this book an excellent pedagogical exposition of spacecraft dynamics and control, valuable for a student or professional who has never before been exposed to this material and wants to come up to speed with the basics of orbital mechanics, attitude kinematics and dynamics, and feedback control theory. A very notable feature of this book lies in the successful unifying treatment of spacecraft orbital dynamics, attitude dynamics, and control using the vectrix calculus. For these reasons, I not only strongly recommend this book for students and practitioners, as well as academic and company libraries, but also have no doubt that this book will earn its place amongst the other excellent treatments of the subject mentioned above.

Signature-Based Time-Series Analysis for System Identification: Methods That Offer Unique Benefits

Abstract: Nonlinear dynamic models are the essential components of the virtual environments that drive today's design, optimization, control, and automation technology. They are the natural choice for characterizing the behavior of biological, ecological, social, and economic systems, as well as artifacts such as aircraft and manufacturing systems. The art and science of developing models in accordance with the observed input/output data and the corresponding analysis is called system identi cation [1]. When dynamic systems can be modeled by first principles, the models are in the form of differential equations, de ned in terms of physically meaningful variables and parameters (coef cients and exponents). Otherwise, the models are in empirical form as neural networks or autoregressive moving-average models [2]. Regardless of the model form, the output data, acquired in the form of a time series, are the basis of system identication.

Fundamentals of Spacecraft Attitude Determination and Control [Bookshelf]

Abstract: There are many excellent texts that cover the orbital dynamics, attitude dynamics, and control of spacecraft, but few discuss spacecraft attitude determination and control in detail This book is devoted to the specific discipline of spacecraft attitude determination and control Both authors are well known in the field; they have both published extensively on a range of spacecraft attitude-related topics as well as implementing attitude estimation and control schemes on real space-bound hardware This real-world expertise is projected onto the pages of the text, increasing its value immensely The design of an attitude determination and control system begins with understanding the fundamental kinematics and dynamics of the system under investigation With this in mind, the book can roughly be divided into three parts: attitude kinematics and attitude dynamics of spacecraft (Chapters 2 and 3), attitude determination and estimation (Chapters 5 and 6), and attitude control (Chapter 7) The operation of sensor and actuators is also discussed (Chapter 4) Each chapter begins with a brief introduction of the topics covered Throughout the chapters, the authors cite the archival literature, thereby creating a comprehensive list of references The chapters end with a series of questions making the text suitable for classroom use