Fixed‐Time Sliding Mode Predictive Speed Control for PMSM Based on Laguerre Function

ABSTRACT To enhance the computational efficiency and tracking performance, a Laguerre function‐based fixed‐time sliding mode predictive discrete speed method (Laguerre‐FTSMP‐DSC) is proposed for speed control of permanent magnet synchronous motor (PMSM). Unlike conventional model predictive control (MPC) with heavy computational loads, the orthogonal Laguerre functions are employed to parameterize control sequences, and the optimization dimensionality is significantly reduced while maintaining control accuracy and dynamic performance. Firstly, the incremental discrete state‐space model (IDSSM) formulation with inherent disturbance rejection is established, and parameter sensitivity for speed prediction error is analyzed. Then, a novel cost function integrating fast fixed‐time sliding mode control is proposed, and the speed controller is designed by minimizing the sliding mode surface deviation. By synergizing sliding mode predictive control with Laguerre function approximation, this approach effectively balances computational feasibility with high‐precision speed tracking performance. Experimental results demonstrate that the proposed controller achieves rapid convergence, reduced overshoot, and strong robustness against parameter variations and external disturbances.