Experimental Validation of a Hybrid BS–RBF–HONTSM Control Strategy for High-Performance Induction Motor Drives

This paper proposes a hybrid control strategy for high-performance induction motor (IM) drives under field-oriented control (FOC), combining a backstepping–RBF-based speed controller enhanced by a higher-order nonsingular terminal sliding mode (HONTSM) mechanism with a HONTSM-based current controller. The proposed speed loop adopts a multilayer structure in which the Lyapunov-based backstepping formulation provides the fundamental nonlinear stability framework, while the RBF network and HONTSM compensator enhance adaptability and robustness. Specifically, the RBF network approximates unknown dynamics in real time, whereas the HONTSM component ensures fast finite-time convergence and strong disturbance attenuation. This synergistic design maintains the structural transparency of backstepping while leveraging the learning capability of RBF and the robustness of sliding mode control. To further improve control performance, an enhanced Harris Hawks optimization algorithm with chaotic Lévy flights (EHHO–CLF) is employed as an offline optimization tool to determine the optimal parameters of the hybrid controller prior to real-time implementation, enabling improved global search efficiency and enhanced transient response. In the inner loop, the HONTSM controller enforces finite-time current tracking with reduced chattering and strong robustness against inverter nonlinearities and parameter uncertainties. Stability of the overall system is rigorously established via Lyapunov-based analysis, ensuring uniform ultimate boundedness of the speed loop and finite-time convergence of the current loop. The effectiveness of the proposed strategy is validated through MATLAB/Simulink simulations and real-time DSP-based experimental implementation, confirming robust high-performance operation under practical nonidealities and demonstrating its applicability to industrial motor drive systems, thereby providing an effective and practical solution for next-generation intelligent IM drives.