Harold Hazen and the theory and design of servomechanisms

Harold Hazen made a significant contribution to the development of control systems during the 1920s and 1930s. He developed a high-performance electromechanical servomechanism, and clarified and extended the available analysis and design techniques for servomechanisms, including methods for relay systems The paper examines in detail the background to Hazen's work, in particular his involvement with Vannevar Bush and Norbert Wiener in the development of computing machines. It also discusses the influence of the work on subsequent developments, and Hazen's personal influence on both teaching and research through his involvement with the work of the National Defense Research Committee and as head of the Electrical Engineering Department at MIT.