PLC-BASED DISCRETE FRACTIONAL-ORDER CONTROL DESIGN FOR AN INDUSTRIAL-ORIENTED WATER TANK VOLUME SYSTEM WITH INPUT DELAY

We present PLC-based fractional-order controller design for an industrial -oriented water tank volume control application. The system comprises input delay which is a typified characteristic in such industrial process control applications. The particular contribution of this work is on discrete fractional-order PID implementation via PLC and its application to the aforementioned realistic water tank test bed. Stability and robustness properties of fractional-order discrete PID feedback-loops for different approximation methods and orders are also shown. Fractional-order controllers are obtained for a variety of stability margin choices, and benefits of the non-integer-order controllers compared to the integer-order PID control are illustrated via simulation and experimental runs on a realistic test-bed.