PREFACE

Control system plays a significant role in the advance ofal Engineering disciplines and science like space vehicle systems, missile guidance systems, robotic systems and all manufacturing and industrial processes. Hence it becomes nece ssary for the engineering students to be familiar with the basic concepts of control systems. This text is designed for an undergraduate course in control systems for engineering students.

This book is organized with 7 chapters. The fundamental concepts, modeling, design and analysis of control systems are presented in a very easiest and elaborative manner. Analysis and design of both continuous time and discrete time control systems are well structured. Throughout the book, carefully chosen examples are presented so that the reader will have a clear understanding of the concepts discussed. In addition MATLAB programs are presented for design and analysis of control systems like block diagram reduction, time response analysis, frequency response analysis and state space analysis with clear explanations.

Chapter 1 presents the basic concepts of control systems and mathematical modeling of mechanical and electrical systems. Development of transfer function of a system, block diagram reduction and signal flow graph methods are dealt with detailed exanmples and solved problems. The MATLAB based approach to block diagram reduction is also introduced in this chapter aided with neat explanation.

Chapter 2 focuses on time response analysis of first order and second systems. The time domain specifications, error analysis for various types of test input signals, the concepts of steady state error, static and generalized error coefiicients are also explained.The rest of this chapter deals with various types of controllers such as P, PI, PD and PID controllers for automatic control systems. The MATLAB programs for step response, impulse response and for any arbitrary input, and estimation of time domain specifications are also presented in this chapter.

Chapter 3 is concerned with frequency response analysis. Various frequency domain specifications, frequency response plots like Bode plot, polar plot, Nichols plot, Nichols chart and closed loop frequency response are presented with clear explanation and more number of solved problems. The MATLAB programs to obtain frequency response plots are provided with neat explanation.

Chapter 4 introduces the concepts of Stability analysis and root locus technique.Location of poles on s-plane for stability, Routh Hurwitz Criterion, Nyquist stability criterion, relative stability, and root locus technique are discussed with mumber of solved umericals. In this chapter the MATLAB programs are included to plot nyquist and root locus plots.

Chapter 5 is devoted for linear system design using compensators. The various types of compensators such as, lag, lead and lag-lead are designed using both Bode diagram and root locus approach. The design of P, PI, PID controllers are also presented in this chapter. The concept of feedback compensation is also discussed briefly.

Chapter 6 deals with State Space analysis of both continuous time and discrete time systems. State space representation, concepts of controllability and observability are given with proper explanation and examples. Finally this chapter concludes with MATLAB programs to obtain state model, transfer function and to check the controllability and observability of the system.

Chapter 7 introduces the concepts of sampled data control systems. The concepts of sampling, reconstruction of sampled signals, Z-transfom, impulse sampling, pulse transfer functionand stability of sampled data systems are discussed in this chapter Several concepts and procedures are illustrated through simple examples rather than generalized formulation. Each chapter provides the foundations and practical implications of their own topic with more number of solved problems for better understanding.

Special care has been taken in presenting the concepts in simple manner and choosing examples & solved problems. The author hopes that the teaching and student community will welcome the book. The readers can feel free to convey their suggestions or criticism for further improvement of the book.