Direct methods for the synthesis of PID compensators: Analytical and graphical design

In this paper direct methods for the synthesis of continuous and discrete PID compensators for a robust control are proposed. Analytical and graphical techniques on the Nyquist plane to meet specifications on phase margin, gain margin and crossover frequency of the close-loop system are presented. Numerical examples demonstrate the effectiveness and the simplicity of the proposed approach, that can be useful both on educational and industrial applications.