Adaptive Fractional Order PI-PD Controllers Applied on a DC Modular Servo System

Fractional calculus extends traditional calculus and provides a comprehensive framework for modelling and control via fractional-order transfer functions (FOTFs). Fractional-order (FO) controllers, including FO-PI and FO-PD, enhance flexibility and performance through the inclusion of an additional tuning parameter, surpassing classical controllers. Despite these advantages, the robustness of FO controllers remains uncertain under varying operating conditions, particularly in nonlinear systems. Adaptive control methods, including Model-Reference Adaptive Control (MRAC), effectively mitigate this limitation by facilitating real-time adjustments to variations in process parameters. This study presents a new control strategy that integrates MRAC with FO control techniques to improve the adaptability and robustness of DC servo motor systems. The DC servo motor, represented as a first-order system, provides the environment for experimental validation. This paper presents the mathematical relations used for tuning the FO-PI and the adaptive FO-PI controllers. The results indicate that this hybrid approach outperforms the classical approach. This research presents the integration of FO and adaptive control for industrial applications.