Foreword

Kinematics as a field of engineering science has been known since the Renaissance, the time of Leonardo da Vinci. Nevertheless, it has gained the most popularity with the development of commercial packages of CAD/CAM systems, and as emphasized in the book, kinematics became a very efficient tool in systems engineering, particularly for multi-degree-of-freedom mechanical systems.

So, if it is so important for designers, then how can it be used in everyday practice, and where it possible to learn about the critical parts of that discipline? The person who is trained on this subject is called a “kinematician” and very often plays the role of a system engineer. There are many traditional technical disciplines that are taught in colleges today, such as mechanical engineering, electrical engineering, software engineering, and so on, but there are no courses in universities where they teach a discipline called systems engineering. The main reason for this phenomenon is that to be qualified as a system engineer, the engineer must gain experience in many different areas. One of these areas is knowledge of kinematics, since kinematics provides the model (even with certain assumptions) of the mechanical system to be designed and developed. From that perspective, this Book on Kinematics teaches the students or engineers some specific practical “tricks” using a large variety of real examples with real applications.

So, the first note here, is the value of this book, which is an illustration of the main steps to be established and solved on the road to designing practically any mechanical system.

Now, what must a modern engineer possess (in terms of knowledge and experience) to fully and efficiently utilize all benefits of “Kinematics?” As it is rightly stated in the Book, there are two or three disciplines that would give the winning ticket on every project involved with multi-degree freedom systems. One of them is the absolute fluency in the manipulation of homogeneous 4 by 4 matrices of coordinate transformation. The second topic, based on the opinion of the author of this book, is the knowledge about different types and configurations for kinematic pairs or joints. Based on the number of applications presented in the book, everyone should be convinced that experience in numerical analysis, specifically in different methods of optimization is a must.

The book demonstrates these main steps in eleven different applications with a very detailed, almost step-by-step explanation of different strategies chosen for a given application. It covers applications from the automotive field, robotics, and a variety of moving platforms, including the basics for driving simulators. The most intriguing is Chapter 11, devoted to the comparison of kinematics between mechanical joints and human biomechanical ones, illustrated by the temporomandibular (TMJ) joint. This justifies the title of the book “Smart Kinematics….”

The material in this book will be very important to gain knowledge about modern methods in mechanical engineering for undergraduates with some prerequisites in the area of linear algebra and matrix methods. It would be very helpful to graduate students, as well as for engineers already graduated from the university environment.

The question with which the Author opens the book is important and necessary.

The events that developed after the 60s of the last centuries with the advent of Robotics posed new challenges and drew attention to old problems that were since then thought of as merely theoretical speculation and not very significant in practice. As an example, to find all the solutions of the 7R mechanism, which later became a strategic issue for the efficient control of industrial robots. Issues that highlighted the importance of Kinematics, not as a subsection of Dynamics, but as an essential part of its foundations.

Indeed, Jack Phillips in his book Freedom in Machinery (1985) states “The study of mechanisms is important because the geometry of mechanical motion (i.e. Kinematics, n.d.r.) is often the crux of a real machine’s design”.

Kinematics under the impulse of new methodologies opened the field to crucial problems such as singularities of mechanisms and their mathematical representation, key problems to deeply understand how to control mechanical systems effectively.

From the first pioneering works of Fydor Litvin and Joseph Duffy, important methods of investigation were developed since the 80s that strongly contributed to the understanding of many problems. Just to mention a few: the kinematic analysis of both the closed chain 7R mechanism (Hong-Yu Lee and Chong-Gao Liang) and the mechanism known as the Gough–Stewart mechanism or, more synthetically, as 6-6 platform (Manfred Husty), have been completely solved; new important closed chain mechanisms (mechanisms later called parallel mechanisms) have been synthesized (Clément Gosselin); the synthesis of spatial mechanisms has regained new vigour and interest (Michael McCarthy), and Kinematic analysis and synthesis are increasingly applied in robotic devices for motor rehabilitation.

The title of Gutman’s book may seem provocative and, reading the index, the content is anomalous and very ambitious. However, reading the chapters, gradually one realizes the value that the approach used by the Author can have on teaching the subject to the students, the next designers.

The book stands out of the ordinary, out of the traditional way of presenting the Kinematics to university students. Likewise unexpected things from what we are familiar with, the first reader's reaction can be of surprise, rejection, criticism, etc., but looking with more attention and free from prejudices, he/she can glimpse the truest content and the potential the book can have in the high-level educational process. However, not everything is easily acceptable, but the whole work represents an approach to the subject absolutely worthy of serious consideration.

Putting in the foreground some applications to teach the basic concepts of Kinematics may seem inefficient, but here lies the point. It is well known the dualism deductive method vs inductive method. This book, indeed, combines the two methods in an original and certainly efficient way for teachers who want to grasp the most creative and positive aspects of both, just adapting them to their educational realities without prejudices.

Gutman's work deals with the study of Kinematics from a completely original point of view, very different from the traditional method consolidated in recent decades. It tries to stimulate the interest of students, to whom the book is mainly addressed, starting from real problems and stimulating the deepening of the theory to better understand its application.

In essence, compared to the classic approach from theory to application, the book moves in several cases in a reverse direction, that is, from application to theory (inductive rather than deductive method).

The book reflects the experience of the Author, firstly a university researcher and then a technician with a long experience gained in the world of advanced motion simulators (in an international leading company).

After the introductory part, where the theoretical bases to deal with kinematic analysis are exposed, the book presents the fundamental problems of a designer, namely the optimization and the analysis of complex industrial systems, to end with important and complex applications related to biomechanical problems.

The subject is largely presented by referring to notable industrial examples, then gradually introducing in Chapter 2 the necessary theoretical concepts to solve the problem at hand. Whilst Chapter 3 refers to the theory in a very general and abstract way. Then it treats the influence of manufacturing errors on the mobility of a mechanism, a very interesting issue, applied to the Uhing mechanism (RCCC) taken as an example.

In general, optimization is not covered in Kinematics textbooks. The treatment of Gutman's book in Chapter 4 does so with great clarity and usefulness for the student, who can easily understand that a real system is always the result of an optimization; either based on an empirical process, which is refined over the years, or, more effectively, on mathematical models easily implemented in computer codes that even low skilful designers can use.

Particular attention to stability, control and trajectory planning of robots is devoted in Chapter 5, while methods for solving the position analysis of robots with 6 degrees of freedom (dof) are exposed in Chapter 6, highlighting their most critical aspects. A gantry system is also presented as an example to show how to deal with the singular configurations of a mechanism. The interesting concept of Phantom dof is introduced in Chapter 7.

Chapters 8, 9 and 10 are devoted to the analysis of complex systems (testing machines) where the methods set out in the previous chapters are used.

Chapter 11 shows how very complex biomechanical systems (tibio femoral joint, knee, ankle, etc.) can be modelled by kinematic elements of an equivalent mechanism, which can be of the utmost importance to design and implement dental prostheses, and to plan surgical interventions.

The book subject is frequently treated colloquially as if one were lecturing students. This makes the exposition less formal, maybe less attractive for the researcher and the professional scholar, but perhaps more accessible and interesting for the students who deal for the first time with these concepts that are anything but immediate (i.e. the modelling of mechanical systems (mechanisms) and the solution of systems of nonlinear equations).

For the depth of the topics and the analytical tools used, the book should be understood for an advanced kinematics course for Master and PhD students.

In conclusion, the book is quite different from most books on Kinematics available on the market. It treats basic and advanced elements of the theory (as many other books do) plus very interesting industrial applications, which are rarely found in the academic literature.

The book represents a balanced synthesis of basic elements of three-dimensional kinematics and examples of application from the industrial world that are very interesting and certainly of keen interest to teachers and a stimulus for students. In particular, students can come across with complex concepts (of kinematics),whose usefulness is frequently not fully understood, applied to the resolution of real problems of strong industrial importance, and then get tangible evidence of their relevance.

This book provides a relevant contribution to education. It is a novelty in the panorama of the books on mechanism Kinematics.

In my opinion, I believe that Gutman's work represents a valid tool for teachers and provides a significant contribution to the high-level training of today's students, who will be the designers of tomorrow.