Optimal and Robust Scheduling for Networked Control Systems tackles the problem of integrating system components—controllers, sensors, and actuators—in a networked control system. It is common practice in industry to solve such problems heuristically, because the few theoretical results available are not comprehensive and cannot be readily applied by practitioners. This book offers a solution to the deterministic scheduling problem that is based on rigorous control theoretical tools but also addresses practical implementation issues. Helping to bridge the gap between control theory and computer science, it suggests that the consideration of communication constraints at the design stage will significantly improve the performance of the control system.
Technical Results, Design Techniques, and Practical Applications
The book brings together well-known measures for robust performance as well as fast stochastic algorithms to assist designers in selecting the best network configuration and guaranteeing the speed of offline optimization. The authors propose a unifying framework for modelling NCSs with time-triggered communication and present technical results. They also introduce design techniques, including for the codesign of a controller and communication sequence and for the robust design of a communication sequence for a given controller. Case studies explore the use of the FlexRay TDMA and time-triggered control area network (CAN) protocols in an automotive control system.
Practical Solutions to Your Time-Triggered Communication Problems
This unique book develops ready-to-use engineering tools for large-scale control system integration with a focus on robustness and performance. It emphasizes techniques that are directly applicable to time-triggered communication problems in the automotive industry and in avionics, robotics, and automated manufacturing.
Table of Contents
Control of Plants with Limited Communication
Models for NCSs
Scheduling and controller codesign methods
Structural and stability analysis
A General Framework for NCS Modeling
Limited communication and schedulers
NCS without ZOH
Periodicity and discrete-time lifting
Extension to multi-networks, subnetworks and task scheduling
Multirate systems, a special case of NCSs
NCSs, a special case of switched and delayed systems
Application to a vehicle brake-by-wire control system
Controllability and Observability
NCSs with ZOH
NCSs without ZOH
Communication Sequence Optimization
Optimizing for ∆
Optimization of NCSs which are multirate systems
Applying the optimization to the vehicle brake-by-wire control system
Optimal Controller and Schedule Codesign
Optimal Schedule Design
Robust Schedule Design
Formulation of an H∞-based cost for performance
Formulation of a discrete H∞-based cost for robustness and performance
Formulation of a sampled-data H∞-based cost for robustness and performance
Optimal design with an example
Application to an Automotive Control System
Vehicle model and controller design
HIL from TTE systems
Experiments on the HIL
Experiments with FlexRay
Schedule Design for Nonlinear NCSs
Discretization of nonlinear affine systems
Sampled-data model of nonlinear NCS
Quadratic cost function for NCS performance
An SOS-framework for local cost computation
Dr. Stefano Longo is currently a lecturer in vehicles electrical and electronic systems in the Department of Automotive Engineering at Cranfield University, UK. His work and his research interests gravitate around the problem of implementing advanced control algorithms in hardware, where the controller design and the hardware implementation are not seen as two separate and decoupled problems, but as a single interconnected one.
Dr. Tingli Su is a researcher at the Beijing Institute of Technology. In 2009 she was invited by the University of Bristol as an exchange Ph.D. student, sponsored by the Chinese Scholarship Council during the first year and Jaguar & Land Rover Research the following year. Within the exchange period, she explored the field of nonlinear network control systems (NCS) with communication constraints.
Dr. Guido Herrmann is a reader in control and dynamics in the Department of Mechanical Engineering at the University of Bristol. His research considers the development and application of novel, robust, and nonlinear control systems. He has been collaborating with several institutions in Australia, China, Malaysia, Singapore, and the USA and has been working with companies such as Western Digital and Jaguar Land Rover.
Dr. Phil Barber, BSc Ph.D. CEng MIET FIMechE, is currently the technical specialist for chassis systems and vehicle capability research at Jaguar Land Rover. Current interests include vehicle dynamics, state estimation, distributed and networked systems for real-time vehicle control, and regenerative braking. A member of the Institution of Engineering and Technology, he serves on the executive team of their Automotive and Road Transport Systems Network.
"… unique in that it blends tools known from optimal and robust control theory to design performance-oriented, robust, and reliable networked control systems (NCSs) with time-deterministic behavior. … For readers with a basic grasp of optimal control, robust control, and communication theory, this books presents a foundation for designing reliable, optimal, and robust controllers across networks. The remarkable points of this book include the development of an engineering tool for NCSs with guaranteed performance and robustness and that the design techniques are applied to hardware-in-the-loop automotive control systems. The material is successfully presented in a form that is pleasant to read. … Overall, I found this book to be a good showcase of recent findings in NCSs by combining tools from optimal and robust control. … This book reads more as a research monograph than a graduate textbook. Hence, it is intended for university researchers (graduate and post-graduate level) in automatic control systems and especially those who work at the intersection of two critical and rapidly developing fields: control theory and network analysis. It could also be used as a supplementary text in an advanced graduate course in network control systems, or as an independent resource. Moreover, it will also be handy to practitioners in industry, since several instances of NCSs exist in the automotive industry (the authors of the book have worked closely with Jaguar and Land Rover research), the aerospace industry, and in process control. It can also be useful to engineers working with chemical processes, industrial control, and nuclear engineering."
—Kyriakos G. Vamvoudakis, Center for Control, Dynamical Systems, and Computation, University of California, Santa Barbara, USA, from IEEE Control Systems Magazine, April 2015
"This book is well organized and well written. The contents are new and interesting."
—Yuanqing Xia, Beijing Institute of Technology
"The book deals with a very interesting topic for the automotive industry. The methods and results can be extended to modern cyber physical systems from all domains. Up until now, a very conservative approach was used in the handling of distributed embedded systems. With the presented methods, it may be possible to take into account the known weaknesses and limitations of networked systems already in the design of controllers and functions early in the development process."
—Dr. Josef Zehetner, Virtual Vehicle Research Center, Graz, Austria
"The book is the first complete treatment that unifies existing techniques to handle networked control systems. In particular, the co-design of the control and communication network scheduling is masterfully explained. This contrasts with most existing literature, where control and communication network scheduling are usually considered separately. … The selection of the contents is spot on. The authors start from a motivating chapter and then ease in the reader to more technical results with the use of illustrative examples. … The authors do a nice job explaining and illustrating the concepts in the chapters by using several examples and explanatory figures. … The material is well presented and would captivate the interest of graduate students, researchers, and control engineers. … This is the first book on a hot topic in the area of networked control systems where a unified framework is presented. The authors skillfully combine tools from robust control theory and communication theory to co-design both the control and network configuration that guarantee closed-loop stability and performance. The book is well written and contains several examples and an interesting application to automotive control systems."
—Seddik M. Djouadi, University of Tennessee, Knoxville, USA
"There is a well-known gap in tools available from control theory and the tools used for in-vehicle network analysis. This book successfully attempts to bridge this gap. The attractiveness of the book lies in the fact that it relies heavily on using industrial-strength and state-of-the-art network analysis tools to convey the message."
—Unmesh Bordoloi, Linköping University, Sweden
"… a great introduction in HIL implementation for development of automotive control systems networked via CAN and FlexRay and a best-of-its-kind example of handling uncertainty through robust schedule design. … The book has a harmonious structure and logical sequence of chapters. … I am sure that I will reference this book in my research publications. … All the discussed methods (i.e., optimal and robust design) have full mathematical formulations and are illustrated with proper examples. … One of the most useful books for readers seeking applicative examples of vehicle-related networked control systems. A vivid reference for researcher-practitioners to build up an HIL test bed focused on the development of vehicle controllers."
—Valentin Ivanov, Ilmenau University of Technology, Germany
"This book is good reading for researchers and students studying network control systems. While the book provides deep technical aspects of network control systems theory, it also provides adequate introduction for readers new to the field. Moreover, the inclusion of practically motivated examples in each chapter and a chapter dedicated to automotive applications makes this book a complete story that will attract readers with both theoretical and practical interest."
—Dr. Dina Shona Laila, University of Southampton, UK
"Networking infrastructure is an integral part of modern control systems, and therefore, understanding how control design methods can take into consideration network properties is very significant. ... The book integrates mathematically rigorous control design approaches with practical design concerns related to networked control systems in general and automotive control software. The emphasis on time-triggered platforms is a major strength. ... The coverage of related problems is very good. ... The book can be used as supplemental material for a graduate class on embedded systems."
—Xenofon Koutsoukos, Vanderbilt University, Nashville, Tennessee, USA
"The book by Longo et al. is self-contained, which covers the topic of NCSs at different levels, from technical results to practical applications. It is unique in that it includes all background materials needed to understand the traditional networked control theory and also introduces up-to-date advances in the scheduling techniques for NCSs with successful application examples. … The materials presented in this book are new. The book not only reviews the existing modelling techniques and theoretical results on the NCSs but also introduces the up-to-date advances in the implementation techniques of NCSs. In particular, the codesign of controllers and communication sequences is now a frontier in the field of NCSs. The techniques introduced in this book are timely. The existing results on the NCSs are theoretical that largely limit their applications in practice. The authors propose a unifying framework for modelling NCSs with time-triggered communication and present corresponding design techniques. Therefore, the book is timely since the proposed techniques well achieve the implementation issue of NCSs. The contents of this book are rich. The book includes all background materials needed to understand the traditional networked control theory and is also a timely reflection of the rapidly developing research area of NCSs. It is comprehensive to capture recent advances of theory, techniques, and applications of optimal and robust scheduling techniques for NCSs. The organization of this book is designed well. The book is composed of ten chapters which are arranged logistically from modelling, approach and application. It is worth mentioning that the book has not been designed to be read from first to last chapter. Some chapters could be omitted by readers according to their individual interests. The nice organization would definitely attract more audiences. The references listed in this book are both comprehensive and up-to-date. All these references are the representatives in the latest development of the NCSs. The references justify again the novelty and timeliness of the book and would play an indicative role for further study of the readers. The prospective audience of this book may include both students and researchers. This book would be an ideal textbook for students since it covers the evolving technologies in the area of current NCSs. Researchers may also benefit from the art of scientific innovation by blending the concepts, methodologies and principles contained in the book. The book would definitely meet the needs of the prospective audiences well. In summary, this book presents the most recent results in NCSs as well as new developments related to scheduling techniques of NCSs. It contains details of case-studies, experimental, simulation and/or other application-related work showing how the theories put forward can be implemented in real systems. This book can serve as an essential reference for both researchers and graduate students who have been engaging in the area related to NCSs."
—Prof. Bo Shen, School of Information Science and Technology, Donghua University, Shanghai, China
"The book is a welcome addition to a recently growing list of books on design of networked control systems. In my opinion, the main strength of the book is its accessible delivery and gentle touch on the essence of the salient issues in networked control (with a focus on robustness and optimization in joint optimization of information transmission and control aspects). …The authors have done an excellent job in writing a very technical and focused manuscript. They are certainly well qualified to take on such a big project."
—Serdar Yuksel, Queen’s University, Kingston, Ontario, Canada