Inspection of Mine Wire Rope Using Magnetic Aggregation Bridge Based on Magnetic Resistance Sensor Array

Early detection of damage to wire ropes used in coal mine winching and traction systems is important for avoiding production delays and for the safety of personnel entering the mine. This article proposes a new magnetic aggregation bridge detection method utilizing a magnetic resistance (MR) sensor array, which addresses the shortcomings of the present methods for testing the integrity of wire ropes used in coal mining operations. First, the structure and types of damage incurred by such ropes are analyzed. The detection principle of the proposed method and the optimization of magnetic induction strength regions are then described. The selection of three types of magnetic sensitivity detection elements is compared and analyzed. On this basis, the magnetic aggregation method for inspecting wire rope, based on MR sensor array, is studied in detail, including the detection effect of including or omitting a magnetic aggregation device. Different structures and sizes of magnetic aggregation devices are examined for their performance effect, showing measures to improve the effect of magnetization detection and selection methods for the MR sensor. A detection method using an MR sensor array combination matched with the magnetic field focusing model was discussed in detail. Finally, the proposed method is experimentally verified. The results show that the prototype sensor based on the proposed method can clearly detect multiple types of damage to wire rope, achieving a maximum signal-to-noise ratio of 60 dB and a considerable detection effect, compared with the conventional magnetic flux leakage defect detection sensor.