ABSTRACT
The development of a relatively simple method for constructing the root locus of the closed-loop characteristic polynomial is due to Evans. This chapter illustrates the application of the derived theoretical results by constructing the root locus of several practical control systems. It presents several theorems which greatly facilitate the construction of the root locus. The positions of the poles of the transfer function of a system in the complex plane characterize completely the system’s stability and play a decisive role in the shape of its time response. The determination of a system’s poles is a problem of special importance in control practice. One of the main problems in control systems is the design of an appropriate controller capable of shifting the poles of the open-loop system to new desired closed-loop pole positions in the complex plane.
