Fractional Order PI Tuning for Integrating Plants with Time Delay

In the last decade, non-integer order controllers have received great attention, due to their capacity of achieving robustness of the controlled loops with respect to gain and parameter variations of the plant. However, despite the general interest, technical literature offers few widely accepted and easy tuning techniques for these new controllers. To overcome the lack of simple tuning rules, we use open-loop shaping ideas for tuning non-integer order PI controllers of integrating plants with time delay. We illustrate the potentiality and limitation of the proposed technique through extensive simulation. Simplicity and satisfaction of requirements are remarkable characteristics of the method.