The design of PID controller for non-oscillating time-delayed plants with guaranteed stability margin based on the modulus optimum criterion

In this paper we analyze the properties of the design of PID controller based on the modulus-optimum criterion for an important class of non-oscillating linear plants with dead time and present some important properties of the settings not published so far. The results are used to design a suitable correction of the settings, which ensures that a sufficient stability margin is preserved. After inclusion of these enhancements a robust design method is obtained, which provides good performance even for systems with long dead time and is easy to implement.

► PID controller settings based on the modulus optimum criterion for a class of linear plants with dead time are analyzed.
► The results are used to design a correction of the settings, preserving a sufficient stability margin.
► A robust design method is obtained, providing good performance even for systems with long dead time, easy to implement.
► A straightforward way for obtaining the modulus optimum settings for linear systems with dead time is presented.