Design of an improved PID control algorithm based on gain and phase margin

Abstract

Background/Objectives: This paper purposed to design an improved PID controller based on the gain and phase margin Specifications using a reduction model with second-order delay.

Methods/Statistical analysis: Find a reduced model with second order and delay time for all models. Then, using this reduced model, we designed a PID controller that ensure that the gain margin or phase margin, and a PID controller that based on the phase margin and the phase margin.

Findings: The method for obtaining the reduced model is such that the real model and reduced model are the same at four critical points in frequency response. Simulation results show that the proposed method can be applied to all models of the first and second and higher order and is superior to the existing methods.

Improvements/Applications: This paper is a stability based controller design method, and other stability is not satisfied. Therefore, a process of combining with other stability is needed in the future. 

Keywords: PID controller, Model reduction, Gain Margin, Phase Margin, frequency Response, Nyquist diagram.