Stability of discrete-time internal model control against several perturbations

Abstract

Internal Model Control (IMC) is a popular control approach that integrates the model of the plant into the controller. In most cases, it is common to have a mismatch between the plant and the model due to noise and disturbance. Actuator constraints may also be another source of instability or performance degradation in IMC. This has lead to the development of IMC structure to sustain its robustness against many different types of uncertainties. This note presents a stability analysis of discrete-time IMC which is subject to saturation and a bounded uncertainty. The stability is guaranteed via one of the discrete counterparts of Popov criterion, namely Jury-Lee criterion (This work was supported by Fundamental Research Grant Scheme (203/PELECT/6071267), Ministry of Education of Malaysia.).