Active Disturbance Rejection Backstepping Cross-Coupling Controller Design for a Magnetic Levitation Vehicle Suspension Frame

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.