An improvement on the PI controller for a class of high-order unstable delayed systems: Application to a thermal process

Abstract

This work addresses the stabilization and control problem of a class of input-output delayed unstable linear systems, i.e. n-order systems with one unstable pole, and possibly one minimum phase zero. The problem is solved employing a modified version of the traditional PI, called the PIf controller, which incorporates a low-pass first order filter. This new scheme allows improving the existing results using the PI controller for high-order systems with time delays. The proposed control strategy is experimentally assessed through the temperature control of a unstable heat flow process.