It is my ambition in writing this book to bring tribology to the study of control of machines with friction. Tribology, from the greek for study of rubbing, is the discipline that concerns itself with friction, wear and lubrication. Tribology spans a great range of disciplines, from surface physics to lubrication chemistry and engineering, and comprises investigators in diverse specialities. The English language tribology literature now grows at a rate of some 700 articles per year. But for all of this activity, in the three years that I have been concerned with the control of machines with friction, I have but once met a fellow controls engineer who was aware that the field existed, this including many who were concerned with friction. In this vein I must confess that, before undertaking these investigations, I too was unaware that an active discipline of friction existed. The experience stands out as a mark of the specialization of our time. Within tribology, experimental and theoretical understanding of friction in lubricated machines is well developed. The controls engineer's interest is in dynamics, which is not the central interest of the tribologist. The tribologist is more often concerned with wear, with respect to which there has been enormous progress - witness the many mechanisms which we buy today that are lubricated once only, and that at the factory. Though a secondary interest, frictional dynamics are note forgotten by tribology.

This book introduces the basic concepts of contact mechanics, friction, lubrication, and wear mechanisms, providing simplified analytical relationships that are useful for quantitative assessments. Subsequently, an overview on the main wear processes is provided, and guidelines on the most suitable design solutions for each specific application are outlined. The final part of the text is devoted to a description of the main materials and surface treatments specifically developed for tribological applications and to the presentation of tribological systems of particular engineering relevance. The text is up to date with the latest developments in the field of tribology and provides a theoretical framework to explain friction and wear problems, together with practical tools for their resolution. The text is intended for students on Engineering courses (both bachelor and master degrees) who must develop a sound understanding of friction, wear, lubrication, and surface engineering, and for technicians or professionals who need to solve tribological problems in their work.

The design of nonlinear controllers for mechanical systems has been an ex tremely active area of research in the last two decades. From a theoretical point of view, this attention can be attributed to their interesting dynamic behavior, which makes them suitable benchmarks for nonlinear control the oreticians. On the other hand, recent technological advances have produced many real-world engineering applications that require the automatic con trol of mechanical systems. the mechanism for de Often, Lyapunov-based techniques are utilized as veloping different nonlinear control structures for mechanical systems. The allure of the Lyapunov-based framework for mechanical system control de sign can most likely be assigned to the fact that Lyapunov function candi dates can often be crafted from physical insight into the mechanics of the system. That is, despite the nonlinearities, couplings, and/or the flexible effects associated with the system, Lyapunov-based techniques can often be used to analyze the stability of the closed-loop system by using an energy like function as the Lyapunov function candidate. In practice, the design procedure often tends to be an iterative process that results in the death of many trees. That is, the controller and energy-like function are often constructed in concert to foster an advantageous stability property and/or robustness property. Fortunately, over the last 15 years, many system the ory and control researchers have labored in this area to produce various design tools that can be applied in a variety of situations.

It is my ambition in writing this book to bring tribology to the study of control of machines with friction. Tribology, from the greek for study of rubbing, is the discipline that concerns itself with friction, wear and lubrication. Tribology spans a great range of disciplines, from surface physics to lubrication chemistry and engineering, and comprises investigators in diverse specialities. The English language tribology literature now grows at a rate of some 700 articles per year. But for all of this activity, in the three years that I have been concerned with the control of machines with friction, I have but once met a fellow controls engineer who was aware that the field existed, this including many who were concerned with friction. In this vein I must confess that, before undertaking these investigations, I too was unaware that an active discipline of friction existed. The experience stands out as a mark of the specialization of our time. Within tribology, experimental and theoretical understanding of friction in lubricated machines is well developed. The controls engineer's interest is in dynamics, which is not the central interest of the tribologist. The tribologist is more often concerned with wear, with respect to which there has been enormous progress - witness the many mechanisms which we buy today that are lubricated once only, and that at the factory. Though a secondary interest, frictional dynamics are note forgotten by tribology.

While writing the book,we have continuously kept in mind the examination requirments of the students preparing for U.P.S.C.(Engg. Services)and A.M.I.E.(I)examinations.In order to make this volume more useful for them,complete solutions of their examination papers up to 1975 have also been included.Every care has been taken to make this treatise as self-explanatory as possible.The subject matter has been amply illustrated by incorporating a good number of solved,unsolved and well graded examples of almost every variety.

Sliding friction is one of the oldest problems in physics and certainly one of the most important from a practical point of view. The ability to produce durable low-friction surfaces and lubricant fluids has become an important factor in the miniaturization of moving components in many technological devices, e.g., magnetic storage, recording systems, miniature motors and many aerospace components. This book will be useful to physicists, chemists, materials scientists, and engineers who want to understand sliding friction. The book (or parts of it) could also form the basis for a modern undergraduate or graduate course on tribology.

The essential introduction to the principles and applications of feedback systems—now fully revised and expanded This textbook covers the mathematics needed to model, analyze, and design feedback systems. Now more user-friendly than ever, this revised and expanded edition of Feedback Systems is a one-volume resource for students and researchers in mathematics and engineering. It has applications across a range of disciplines that utilize feedback in physical, biological, information, and economic systems. Karl Åström and Richard Murray use techniques from physics, computer science, and operations research to introduce control-oriented modeling. They begin with state space tools for analysis and design, including stability of solutions, Lyapunov functions, reachability, state feedback observability, and estimators. The matrix exponential plays a central role in the analysis of linear control systems, allowing a concise development of many of the key concepts for this class of models. Åström and Murray then develop and explain tools in the frequency domain, including transfer functions, Nyquist analysis, PID control, frequency domain design, and robustness. Features a new chapter on design principles and tools, illustrating the types of problems that can be solved using feedback Includes a new chapter on fundamental limits and new material on the Routh-Hurwitz criterion and root locus plots Provides exercises at the end of every chapter Comes with an electronic solutions manual An ideal textbook for undergraduate and graduate students Indispensable for researchers seeking a self-contained resource on control theory

Friction and Wear of Materials Second Edition Written by one of the world’s foremost authorities on friction, this classic book offers a lucid presentation of the theory of mechanical surface interactions as it applies to friction, wear, adhesion, and boundary lubrication. To aid engineers in design decisions, Friction and Wear of Materials evaluates the properties of materials which, under specified conditions, cause one material to function better as a bearing material than another. Featured also are thorough treatments of lubricants and the sizes and shapes of wear particles. This updated Second Edition includes new material on erosive wear, impact wear, and friction. Professor Rabinowicz’s book will be especially welcomed by mechanical and design engineers, surface scientists, tribologists and others who design, produce and operate products, machines and equipment which involve friction and its effects.

Today, switched reluctance machines (SRMs) play an increasingly important role in various sectors due to advantages such as robustness, simplicity of construction, low cost, insensitivity to high temperatures, and high fault tolerance. They are frequently used in fields such as aeronautics, electric and hybrid vehicles, and wind power generation. This book is a comprehensive resource on the design, modeling, and control of SRMs with methods that demonstrate their good performance as motors and generators.