Implementation of Fractional-order PID Controller Using Industrial DCS with Experimental Validation

Abstract

Generally, the PID controllers are used profusely in industrial processes and highly practical. Simultaneously, the Fractional-order PID (PI <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">λ</sup> D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">μ</sup> or FOPID) controller is a natural extension of the PID controller. In this study, the FOPID controller's implementation is performed in an industrial distributed-control system used here to control a laboratory unit's level. A user-defined function block in ABB-DCS software is built to make the FOPID controller implementation possible. In order to create this new function block, one of the FOPID controller discretization methods is first presented and used for getting the discrete form. A system response's comparisons using FOPID and the conventional PID controller are accomplished via simulation (using a particle swarm optimization and genetic algorithms) and experimentally (using the experimental setup). This experimental setup consists of the controller (ABB-DCS AC 700F2), which is connected to a desktop computer via ethernet cable, and the plant (Lab-Volt Level-Process Station), which is connected to the analog module of the DCS. A relative development in system response is shown in the results using the advanced FOPID controller comparison with classical PID and traditional FOPID controllers.