Dual sliding mode control of linear maglev synchronous motor based on novel extended state observer

Abstract

In order to improve the convergence speed and disturbance immunity of the linear maglev synchronous motor (LMLSM) maglev system, this paper proposes a dual sliding mode control strategy based on a novel expanded state observer (NESO). Firstly, a dual terminal sliding mode (DTSM) surface is designed, which exhibits the desired dynamic and steady state performance. The problem of the TSM singularity is solved by the dual sliding mode technique, which turns the control signal into a continuous switching control through the filtering function and effectively reduces the jitter problem. Since the maglev system is susceptible to uncertainties such as nonlinearity, strong coupling and external perturbations, which affect its tracking accuracy, a continuous smooth ESO is designed to estimate and compensate for these uncertainty perturbations, thus solving the problem that the traditional ESO is continuous but not derivable at the switching point. Then, it is proved that the DTSM control strategy based on NESO converges to the equilibrium point in finite time by Lyapunov function. Finally, the effectiveness and superiority of the proposed strategy are verified on the LMLSM maglev system platform.