Event-Driven Robust Model Predictive Control for Electromagnetic Levitation Systems With Voltage Fluctuation Constraints

In this article, the levitation control problem of electromagnetic levitation systems subject to track irregularities, air gap and vertical velocity and voltage fluctuation constraints are taken into account. An equivalent tracking model is established, which incorporates the flux density as a state variable to simplified the derivation of the robust constraints. With these robust constraints in place, a novel robust hierarchical control strategy is developed, which combines feedback linearization techniques with event-triggered robust model predictive control (ERMPC). Moreover, the theoretical properties are investigated, including recursive feasibility and closed-loop stability. Finally, to verify the superiority of the proposed control, simulations are conducted and compared with the conventional ERMPC, RMPC algorithms, and the proposed strategy under different parameter environments. The results demonstrate that the proposed algorithm can effectively reduce the frequency of controller updates and improve levitation performance while addressing various constraints, thereby enhancing system stability and safety. Note to Practitioners—The main purpose of this paper is to improve levitation performance while considering various constraints and reducing the frequency of the controller updates. Most existing levitation control strategies have overlooked the hazards posed by sharp voltage fluctuations, which may result in control failure, increased energy consumption, and even security risks. To address these control challenges in electromagnetic levitation systems with consideration of security and physical constraints, a novel robust hierarchical control strategy is proposed. This strategy combines feedback linearization techniques with event-triggered robust model predictive control (ERMPC). It aims to mitigate the impact of the track irregularities and achieve a satisfactory tradeoff between levitation performance and controller computing resources. The recursive feasibility and closed-loop stability of the proposed scheme are analyzed, and its superiorities are confirmed through the numerical simulations. However, further verification through experiments is necessary.