Feedback control is a classic technique for modeling a closed-loop controller in a dynamic system. The output of the system is fed back as a reference value through a sensor measurement. Guided by the difference between the reference and the output, the controller then changes the input to the system. The term “feedback control” comes from the information path in the system: the output is used as part of the input to the system. A linear control system can be described by the space of regulated functions and the coefficient matrices of bounded variation. Hence, linear feedback control systems have wide uses in modeling various closed-loop control systems. Either analytical or numerical solutions of such modelings serve as good guidelines for practical system control and optimizations. Since an analytical solution may not exist for every linear control system, MATLAB can be used as a tool for deriving a numerical solution.

This book discusses analysis and design techniques for linear feedback control systems using MATLAB. It introduces feedback control methods and mathematical models of feedback control systems. The topics covered in the book include the analysis of linear control systems, the analysis of nonlinear systems, model-based controller design, the proportional integral derivative (PID) controller design, the robust control systems design, and the concept of fractional-order controllers.

A distinguishing feature of this book is the organization of the presentation of the material. The book begins with a summary of the properties of linear systems and addresses modeling and model-reduction issues. Next, it provides in-depth coverage of time domain, complex plane, and frequency-domain techniques. Later, it covers model-based controller designs, PID controllers, and robust control designs. Lastly, it covers the fractional-order control that is useful for robust control engineering practice. To facilitate self study, the book also covers the MATLAB companion package, CtrlLAB, in the Appendix. CtrlLAB can be used as a feedback control system and analysis tool. CtrlLAB allows readers to quickly learn analysis and simulations of control models through a user-friendly graphical user interface (GUI). The problems covered and example scripts provided help readers to strengthen their understanding of the material.

This book has made good efforts in building up the connection between the theoretical description of a feature derived in a control system and the corresponding description in CtrlLAB--a MATLAB implementation of a toolkit for the analysis of linear feedback systems. Hence, the features in analytical modeling can be easily illustrated using the numerical results from the MATLAB computations. Moreover, the CtrlLAB code segments offered in different sections can be further used as building blocks in constructing MATLAB-based numerical tools for analyzing various linear control systems.

Possibly missing from the book is a caution to the reader as to the limitations of CtrlLAB’s abilities. A linear feedback system can be stable or unstable due to the fact that feedback information is used as part of the input to the system. When applying CtrlLAB in analysis and design, there is the possibility of incorrect numerical results. A separate chapter on CtrlLAB’s limitations would increase the book’s usefulness.

This book can be a useful reference to readers with different levels of knowledge on linear feedback control. It reduces the mathematics and uses many MATLAB working examples. The short scripts and plots used in the text are a good resource. For beginners, this book provides an efficient entrance into the field of linear feedback control. For intermediate readers, the book bridges the gap between control theory and the use of MATLAB for control systems. For practicing engineers, the book can be used as a handy reference. It can be used as a professional resource for control systems engineers, a classroom textbook for students, or a self-study guidebook on systems control.