An Adaptive Backstepping Sliding-Mode Control for Improving Position Tracking of a Permanent-Magnet Synchronous Motor With a Nonlinear Disturbance Observer

To provide reliable position control for a permanent-magnet synchronous motor (PMSM) under conditions of lumped disturbances such as external load torque fluctuation and system parameter variation, an adaptive backstepping sliding-mode (ABSMC) with nonlinear disturbance observer (NDO) is proposed. An ABSMC non-cascade technique that employs position-current single-loop structure rather than conventional cascade vector the PMSM. This method uses Lyapunov theory to design law ensure reaches desired value in finite period time consequently achieves rapid transient response. The proposed incorporates convergence gain avoid large overshoot point-to-point command. NDO estimate unknown feed-forward compensation ABSMC, improving robustness reducing steady-state error. methods are applied industrial drive confirm their validity real-world operating environments.