The Tuning Algorithm of Controllers in Multiple-Loop Feedback Control System with Three Contours

Abstract

A tuning algorithm of linear controllers P, PI, PID in multiple-loop feedback control systems with three contours is proposed in this paper. The control objects consists from three subprocesses, which are described by dynamical models with inertia (third order) and time delay. The controllers P, PI, PID in the inertial contours 1 and 2 and in the external contour are tuning using the maximal stability degree method. The tuning process of linear controllers P, PI, PID consists from three stage: in the first stage it was made the tuning of P, PI controllers in the first internal contour, at the second stage it was made the tuning of P, PI controllers in the second internal contour, at the third stage it was made the identification of the transfer process of first and second internal contour, after identification it was obtained the equivalent transfer function, and for this equivalent transfer function it was tuning the P, PI and PID controllers using the maximal stability method in the external contour. The obtained results were optimized in MATLAB using the NCD Outport block and compared with the results obtained for the case of tuning P, PI, PID controllers using Ziegler Nichols method.