This textbook is designed to help the student learn the basic techniques necessary to begin the practice of automatic control engineering. The subject matter of the book, classical control theory, is a study of the dynamics of feedback control systems. Particular emphasis is placed upon the way in which the physical properties of the individual interconnected devices in a system influence the dynamic performance of the entire control system. Although classical control theory is normally taught to engineering students during their third or fourth year of study, it may also be learned by interested persons having a comparable background in mathematics, physics, and engineering.

Classical control theory was developed from the feedback amplifier technology of the 1920s and 1930s. It was first applied to automatic control systems for machine tools, industrial processes, and military equipment of many types. Although these applications bore little outward resemblance to their electronic amplifier antecedents, they all relied on the same principle of feedback for their remarkable performance. Increased demand for control systems in the 1940s gave rise to the branch of engineering known as automatic control. Research groups were formed in industry to develop and apply classical control theory. Engineering departments in universities offered seminars and courses in automatic control, and textbooks on the subject began to appear, including my earlier book which was published in 1962 (Introduction to Automatic Control Systems, Wiley & Sons, New York).