Multi-objective Optimization of a Fractional-Order Control System for an EMS-Type Maglev Model

This paper presents a multi-objective optimization approach for a fractional-order control system for electricmagnetic suspension (EMS) type magnetic levitation (maglev) models, aiming to optimize the non-linear magnetic buoyancy control parameters. Firstly, a multi-body dynamics model of an EMS-type maglev vehicle with a fractional-order PID control system is developed. To fulfill the multi-objective requirements and optimize the fractional order parameters, an improved multiobjective optimization algorithm is proposed. The Sperling index and the magnitude of the vertical suspension gap variation are employed as the optimization objectives. Then, the aforementioned multi-objective optimization algorithm is applied to the constructed multi-body dynamics model to perform multiobjective optimization of the control parameters. Finally, the Pareto front solution is calculated and the optimal control parameters are obtained. The results demonstrate that the optimized control parameters can significantly reduce the vertical suspension gap and Sperling index during operation, with the reduction in the vertical suspension gap amplitude and its standard deviation being 10∼73%, and the reduction in the Sperling index being 8∼13%.