Some Fundamental Considerations in the Application of Automatic Control to Continuous Processes

Abstract

Abstract Certain fundamental characteristics of continuous processes and automatic controllers are presented in this paper in order to establish a framework for a suggested terminology. A specific object is to assist in the work on standard terms being conducted by the A.S.M.E. Committee on Industrial Instruments and Regulators. The authors’ treatment is essentially nonmathematical. Illustrations used deal primarily with the control of temperature. Attention is focused on the effects of important process lags through the analysis of elementary heating systems in which they are individually predominant. Characteristics of automatic control systems are discussed without going into the constructional details of particular mechanisms. Curves showing the response to sudden load changes serve to illustrate different types of corrective action. The final section of the paper is devoted to a critical discussion of suggested terms.