Adaptive Sliding-Mode Speed Control Integrated Extended State Observer for Maglev DC Excited Linear Synchronous Motor

Classical speed controller is challenged by nonlinear factors such as discontinuities in the stator iron cores, fluctuations in excitation current, and variations in the suspension air gap, leading to speed fluctuations, especially during low-speed operation of maglev trains. To address these issues and enhance control performance, a robust speed controller is proposed in this article, which inherently integrates the advantages of sliding-mode control (SMC) and extended state observer (ESO). Specifically, an adaptive sliding-mode reaching law is developed that directly incorporates ESO, eliminating the need for a separate disturbance observer to compensate for the control signal. This integration enables real-time disturbance updates, reducing the chattering effect typically associated with traditional exponential reaching laws (ERLs) and improving dynamic performance under significant disturbances. Subsequently, the mathematical model of the dc excited linear synchronous motor (LSM) is established, and a speed controller is designed using forward Euler’s discretization scheme with the adaptive sliding-mode reaching law. Finally, a dc excited LSM experimental platform is built to validate the proposed method. Comparative experiments demonstrate the superior dynamic performance and fluctuation suppression capabilities of the proposed method.