Theoretical Consideration of Retarded Control

Abstract This paper is concerned with a theoretical study of the control of a single-capacity process with dead-period lag. Characteristic equations corresponding to the application of proportional, proportional-plus-derivative, proportional-plus-reset, and proportional-plus-reset-plus-derivative responses are used to graph the controller parameters necessary to obtain a desired degree of stability. The degree of stability is taken to be associated with the amplitude ratio of the lowest-frequency harmonic mode. Effects of the various controller parameters are shown and a method is suggested to determine the adjustable parameters for a desired degree of stability.