PM Diagram of the Transfer Function and Its Use in the Design of Controllers

This paper presents an enhanced Root Locus diagram that consists of the representation of the phase and the magnitude of the transfer function G(s) of a system. The magnitude is represented in decibels and the phase is represented by colors. It also presents how to use it to calculate different kinds of controllers. An important characteristic of this diagram is that permits to read the phase and the gain margins directly and the imaginary axis cut represents the Bode diagram. It is also possible to put the grid with damping ratio ζ and frequency ωn.