The root locus method

The root locus method is arguably the most powerful tool in the design engineer’s toolbox to design a feedback control system that meets the design specifications. The significance of s s -plane roots for a system’s dynamic response was highlighted in Chapter 9 . The root locus method allows to determine the traces of the roots in the s s -plane as any one process parameter (for example the controller gain) is varied. Conversely, the root locus method allows to determine the specific value of a process parameter for a desired root location, and with it, for a desired dynamic response.