Fault Diagnosis for Levitation-Gap Sensor of Maglev Train Based on the Tracking Differentiator

Abstract

To determine the additive fault and multiplicative fault of gap sensor, based on improved step-size sampling control of the optimal tracking differentiator, a fault diagnosis method for levitation-gap sensor of electromagnetic suspension (EMS) medium-speed maglev trains is proposed. The model of single electromagnet suspension system is established first. The tracking and differentiation effect of the classic tracking differentiator and the optimal tracking differentiator for gap sensor signal is obtained by Simulink. Based on the analysis of signal time domain features, the comparison of the effect is obtained. The result shows that the noise interference can be further reduced by tracking differentiator with sampling control. Meanwhile, the differentiator maintains good tracking performance. Diagnose the fault of the gap sensor with improved sampling control of the optimal tracking differentiator. Based on the analysis of amplitude variation of gap residual signal, the type of additive and multiplicative fault of gap sensor is distinguished.