Robust tuning of a generalized predictor-based controller for integrating and unstable systems with long time-delay

Abstract

In this work, a general structure to control long time-delay plants is proposed and an easy methodology to tune the control parameters is outlined. All the sensitivity transfer functions are delay free. The proposed scheme is equivalent to the Smith predictor but able to cope with any kind of systems, including nonminimum phase, unstable and integrating plants. The controllers are designed based on the delay free model. Contrary to other approaches, other than for the digital implementation, no delay approximation is used. A tuning parameter is provided in order to reach an intuitive tradeoff between performance and robust stability. A comparative analysis with respect to recently successful proposals shows a substantial improvement in the performance/robustness tradeoff as well as in the tuning process.