Fractional filter IMC-TDD controller design for integrating processes

Abstract

A modified internal model control (IMC) with fractional-order tilt double derivative controller (FOTDD) is proposed for integrating processes. This method is extended for all three types of process models, namely, integrating plus time delay process (IPTD), double integrating plus time delay process (DIPTD) and integrating plus first order plus time delay process (IFOPTD). The feedback controller is designed in an IMC framework that can quickly obtain from the plant parameters. Then, the fractional IMC filter can be tuned from the obtained explicit expressions for easy access in practice. A numerical study is conducted with various examples from literature for all types of integrating models. The results are compared with current methods in terms of setpoint tracking, disturbance rejections and parameter perturbation. Even considering a fractional-order derivative controller, the results demonstrated a simple, robust structure with fewer tuning parameters.