MATLAB® and Its Applications in Engineering: [Based on MATLAB 7.5 (R2007b)]

12.2. Root Locus

The location of closed-loop poles in the s-plane gives an idea about stability and transient response of a closed-loop system. With the variation of any system parameter, these poles move from their locations. The knowledge about change in the location of poles is quite useful in the design of a closed-loop system. To find out the location of the poles, the classical techniques of factorizing the characteristic polynomial and determining its roots are used. However, if any system parameter is varied for adjustments, the characteristic equation changes and computations have to be repeated to calculate the roots. The root locus technique, introduced by W.R. Evans, provides a simple graphical method of finding the roots of characteristic ...