Design of a New Model Predictive Controller for Networked Control Systems Subjected to Variable Network Time Delays

Sadat Hosseini, Mohammad Ali; Salahshoor, Karim

Design of a New Model Predictive Controller for Networked Control Systems Subjected to Variable Network Time Delays

Authors

M. A. Sadat Hosseini

K. Salahshoor

Department of Automation and Instrumentation, Petroleum University of Technology, Ahwaz, Iran

Abstract

In this paper, a novel methodology is proposed to improve performance of the Networked Control System (NCS) in the face of random time-delays, using Model Predictive Controller (MPC) approach. For this purpose, a new state-feedback MPC structure is developed to cope with random network time-delays when the system is subjected to uncertainties with state and control constraints. The main idea is to reduce the disturbing effect of random network time-delays on regulatory performance of the NCS using a new robust formulation in MPC design. A terminal penalty constraint has been added to the finite horizon objective function to guarantee the stability of the system stability. Finally, applicability of the presented method is evaluated in a real pilot plant within a NCS configuration, being realized by an industrial Ethernet and Foundation Fieldbus technology. It is demonstrated that the proposed online methodology is effective to provide a better performance, having faster response, smaller overshoot and stronger robustness compared to the conventional MPC method with less aggressive control actions.

Keywords

Network control system

Network-induced delay

Model Predictive Controller

Random time delay