Revised and edited for optimum clarity, this text offers a thorough analysis of the principles of classical and modern feedback control. Organizing topic coverage into three sections - linear analog control systems, linear digital control systems, and nonlinear analog control systems - it strives to help students understand the difference between mathematical models and the physical systems that the models represent. This edition adds a section on time-scaling differential equations, helping students relate the transfer functions of systems examples to those of practical systems, additional practical applications, and entirely new end-of-chapter problems.