Extended State Observer based Integral Sliding Mode Control of Maglev Systems with Enhanced Chattering Alleviation

This paper investigates the development of a robust controller for regulating the magnetic levitation system, in the presence of multiple sources of uncertainties and disturbances. The proposed control strategy is designed by employing the extended state observer (ESO) with integral sliding mode control (ISMC). The proposed scheme attenuates all the uncertainties without using the upper bound knowledge of uncertainties. The application of ESO compensates for the effect of uncertainties and disturbances, which helps in significantly reducing the input chattering from ISMC because the discontinuous control of ISMC is not primarily employed for disturbance rejection. The ISMC is exploited to improve the system convergence rate and ensure robustness from the starting time $t=0$ by eliminating the reaching phase. The theoretical analysis of the closed-loop system guarantees the asymptotic convergence of system states. Besides, the performance of the proposed methodology is validated through numerical simulation. Moreover, the efficacy of the proposed controller is also illustrated by comparing its simulation results with a state-of-the-art method.