Fractional Order Intelligent Robust Controller for a Flexible Link Robot Manipulator: Real-Time Experimental Implementation

The study introduces an effective control approach designed for a flexible single-link robotic manipulator, offering advantages such as operational capability in harsh environments, ease of component movement, and lower manufacturing and maintenance costs compared to rigid manipulators. Despite these advantages, controlling such systems remains challenging due to their nonlinear dynamics and the unwanted vibrations caused by link flexibility, which can significantly affect positioning accuracy and stability. To address these challenges, the proposed fractional-order fuzzy sliding mode controller (FO-FSMC) integrates the robustness and stability features of sliding mode control with the adaptability and decision-making capability of fuzzy logic, while also exploiting the precision and memory characteristics offered by fractional calculus. The performance and effectiveness of the proposed control strategy are verified through practical real-time implementation on a single-link flexible robotic manipulator. The results show that the proposed FO-FSMC under different inputs exhibits superior tracking accuracy and faster convergence compared to the classical PID controller. Compared with the conventional SMC, the FO-FSMC achieved slightly higher accuracy and smoother control signals for sinusoidal and mixed inputs, while it showed significant improvement for pulse and step inputs with lower IAE and RMSE, minimum tracking error, and faster adaptation. These results establish FO-FSMC as a robust and practical candidate for real-time control of flexible manipulators, making it well-suited for diverse industrial and research applications

Keywords:

Single link flexible robot manipulator , Sliding mode control , Fuzzy Control , Fractional Calculus , PID Control , Experimental results , uncertainties