Comparison and Analysis of Signal Processing Methods for Induction Loop-Cable Position and Speed Detection System

Abstract

The mid-speed maglev train adopts synchronous traction. Only the real-time acquisition of the position and speed information of the train can realize the closed-loop traction of the train. The signal processing of the position and speed detection unit of the train is directly related to the accuracy of the position and speed information. The comparison and analysis of three kinds of signal processing methods, such as amplitude extraction method based on envelope detection, phase extraction method based on XOR comparison and position information extraction method based on synchronous demodulation, show that the signal processing based on synchronous demodulation has obvious advantages. This paper proposes synchronous demodulation based on phase-locked loop. The demodulation method proves that synchronous demodulation based on phase-locked loop method can simultaneously demodulate both the amplitude and phase information in the signal, and can effectively suppress the influence of the traction traveling wave, and has strong noise reduction capability.