The electromagnet levitation control system is the core of maglev trains, but various external disturbances make the design of the controller difficult. In addition, multiple electromagnet maglev systems are coupled, and the independent control mode lacks the necessary synchronization coordination mechanism. This study proposes a linear expanded state observer (LESO)–backstepping control method with double cross coupling of air gap and velocity for the levitation frame of electromagnetic suspension maglev vehicles to eliminate external disturbances and unknown influences, thus improving the synchronization performance of each point on the levitation frame. A virtual controller is designed with the backstepping control strategy, and the unknown disturbances in the controller are compensated for by LESO. A single-electromagnet control strategy is derived. Then, the synchronization error among the levitation points is used as an additional feedback signal for the input of the four levitation point controllers to demonstrate the closed-loop stability of the system under the proposed strategy. Results demonstrate the tracking effect of the observer and the superiority of the proposed method in improving the synchronization and tracking performance of the levitation frame points.

Electromagnetic levitation control is a core technology for ensuring the stable operation of maglev trains. To enhance the disturbance rejection capability and stability of the levitation system, an IWOA-ISMC control strategy is proposed in this paper. First, a single-electromagnet levitation model with two degrees of freedom is established, in which the effects of spring stiffness and damping are taken into account. Based on this model, an integral sliding mode controller (ISMC) is designed. However, manual parameter tuning based on engineering experience makes it difficult to obtain an optimal parameter combination, and inappropriate controller parameters may lead to significant performance degradation. To address this issue, an improved whale optimization algorithm (IWOA) is introduced to globally optimize the key parameters of the ISMC, resulting in an IWOA-ISMC tailored to the proposed model. Comparative simulations under track irregularity conditions and sudden force disturbances induced by track irregularities are conducted. The results demonstrate that, compared with ISMC, PID, and backstepping controllers, the proposed IWOA-ISMC approach exhibits superior disturbance rejection performance and robustness.