11 Graphical Methods for Control Systems

Up to this stage, the methods and techniques applied to the feedback control systems are analytical and in both the time and s-parameter domains. In many situations when the systems are linear, graphical methods may prove to be very useful to reveal system characteristics and performance. In a sense, these graphical methods compress a great deal of information in the time domain into the parameter domain in a single figure. The parameter domains considered in this chapter are the s-parameter domain of the Laplace transformation, and the ω-parameter domain of the frequency response function. The frequency response function can simply be obtained by replacing the s-parameter of the system transfer function with iω.