Relay Tuning Of Pid Controllers

This book presents comprehensive information on the relay auto-tuning method for unstable systems in process control industries, and introduces a new, refined Ziegler-Nichols method for designing controllers for unstable systems. The relay auto-tuning method is intended to assist graduate students in chemical, electrical, electronics and instrumentation engineering who are engaged in advanced process control. The book’s main focus is on developing a controller tuning method for scalar and multivariable systems, particularly for unstable processes. It proposes a much simpler technique, avoiding the shortcomings of the popular relay-tuning method. The effects of higher-order harmonics are incorporated, owing to the shape of output waveforms. In turn, the book demonstrates the applicability and effectiveness of the Ziegler-Nichols method through simulations on a number of linear and non-linear unstable systems, confirming that it delivers better performance and robust stability in the presence of uncertainty. The proposed method can also be easily implemented across industries with the help of various auto-tuners available on the market. Offering a professional and modern perspective on profitably and efficiently automating controller tuning, the book will be of interest to graduate students, researchers, and industry professionals alike.

Recognising the benefits of improved control, the second edition of Autotuning of PID Controllers provides simple yet effective methods for improving PID controller performance. The practical issues of controller tuning are examined using numerous worked examples and case studies in association with specially written autotuning MATLAB® programs to bridge the gap between conventional tuning practice and novel autotuning methods. The extensively revised second edition covers: • Derivation of analytical expressions for relay feedback responses. • Shapes of relay responses and improved closed-loop control and performance assessment. • Autotuning for handling process nonlinearity in multiple-model-based cases. • The impact of imperfect actuators on controller performance. This book is more than just a monograph, it is an independent learning tool applicable to the work of academic control engineers and of their counterparts in industry looking for more effective process control and automation.

The relay feedback test (RFT) has become a popular and efficient in process identification and automatic controller tuning. Non-parametric Tuning of PID Controllers couples new modifications of classical RFT with application-specific optimal tuning rules to form a non-parametric method of test-and-tuning. Test and tuning are coordinated through a set of common parameters so that a PID controller can obtain the desired gain or phase margins in a system exactly, even with unknown process dynamics. The concept of process-specific optimal tuning rules in the nonparametric setup, with corresponding tuning rules for flow, level pressure, and temperature control loops is presented in the text. Common problems of tuning accuracy based on parametric and non-parametric approaches are addressed. In addition, the text treats the parametric approach to tuning based on the modified RFT approach and the exact model of oscillations in the system under test using the locus of a perturbedrelay system (LPRS) method. Industrial loop tuning for distributed control systems using modified RFT is also described. Many of the problems of tuning rules optimization and identification with modified RFT are accompanied by MATLAB® code, downloadable from http://extras.springer.com/978-1-4471-4464-9 to allow the reader to duplicate the results. Non-parametric Tuning of PID Controllers is written for readers with previous knowledge of linear control and will be of interest to academic control researchers and graduate students and to practitioners working in a variety of chemical- mechanical- and process-engineering-related industries.

Recognising the benefits of improved control, this book aims to provide simple and yet effective methods of improving controller performance. It bridges the gap between the conventional tuning practice and new generations of autotuning methods. Practical issues facing controller tuning are treated, such as measurement noises, process nonlinearity, load disturbances, and multivariable interaction, and tools are also given. Numerous worked examples and case studies are used to illustrate the autotuning procedure, and MATLAB programs to execute autotuning steps are given. This book is intended to be an independent learning tool, and is particularly invaluable to practitioners and scientist, as well as graduate and undergraduate students. The reader will therefore find it useful, particularly as it is applicable to engineering practice

Recently, a great deal of effort has been dedicated to capitalising on advances in mathematical control theory in conjunction with tried-and-tested classical control structures particularly with regard to the enhanced robustness and tighter control of modern PID controllers. Much of the research in this field and that of the operational autonomy of PID controllers has already been translated into useful new functions for industrial controllers. This book covers the important knowledge relating to the background, application, and design of, and advances in PID controllers in a unified and comprehensive treatment including: Evolution and components of PID controllers Classical and Modern PID controller design Automatic Tuning Multi-loop Control Practical issues concerned with PID control The book is intended to be useful to a wide spectrum of readers interested in PID control ranging from practising technicians and engineers to graduate and undergraduate students.

This unique book is the only recent summary presenting a comprehensive, up-to-date and detailed treatment of relay feedback theory, the use of relay feedback for process identification and the use of identified models for general control design in a single volume.

The effectiveness of proportional-integral-derivative (PID) controllers for a large class of process systems has ensured their continued and widespread use in industry. Similarly there has been a continued interest from academia in devising new ways of approaching the PID tuning problem. To the industrial engineer and many control academics this work has previously appeared fragmented; but a key determinant of this literature is the type of process model information used in the PID tuning methods. PID Control presents a set of coordinated contributions illustrating methods, old and new, that cover the range of process model assumptions systematically. After a review of PID technology, these contributions begin with model-free methods, progress through non-parametric model methods (relay experiment and phase-locked-loop procedures), visit fuzzy-logic- and genetic-algorithm-based methods; introduce a novel subspace identification method before closing with an interesting set of parametric model techniques including a chapter on predictive PID controllers. Highlights of PID Control include: an introduction to PID control technology features and typical industrial implementations; chapter contributions ordered by the increasing quality of the model information used; novel PID control concepts for multivariable processes. PID Control will be useful to industry-based engineers wanting a better understanding of what is involved in the steps to a new generation of PID controller techniques. Academics wishing to have a broader perspective of PID control research and development will find useful pedagogical material and research ideas in this text.

The vast majority of automatic controllers used to compensate industrial processes are of PI or PID type. This book comprehensively compiles, using a unified notation, tuning rules for these controllers proposed over the last seven decades (1935-2005). The tuning rules are carefully categorized and application information about each rule is given. The book discusses controller architecture and process modeling issues, as well as the performance and robustness of loops compensated with PI or PID controllers. This unique publication brings together in an easy-to-use format material previously published in a large number of papers and books.This wholly revised second edition extends the presentation of PI and PID controller tuning rules, for single variable processes with time delays, to include additional rules compiled since the first edition was published in 2003.