Signal acquisition system for broken wire of elevator wire rope based on TMR sensor

Abstract

Aiming at the problems of low detection accuracy, large size and quality of the detection equipment, and difficulty in online monitoring in the magnetic flux leakage detection of elevator wire ropes, a broken wire signal acquisition system was built based on the tunnel magnetoresistance sensor TMR2703, and a dual-loop excitation device was designed and simulated to verify. The dipole model determines the detection direction of the sensor, acquires the magnetic flux leakage signal with the signal preprocessing circuit and the differential detection ring, develops the host computer in LabVIEW, displays the broken wire signal waveform in real time, and stores the collected data in the form of TDMS files, completed the feature extraction of broken wire signals. Experiments show that the system can collect the magnetic flux leakage signal of the wire rope in real time, and can accurately extract the characteristic value of the magnetic flux leakage signal with different numbers of broken wires. The peak value, valley value, peak-to-peak value and signal wave width of the signal have an increase with the number of broken wires. The law of increase can be used to judge the damage degree of the wire rope according to the detection waveform.