Double-source magnetic detection system and method for local damage of mine hoisting steel wire rope

Abstract

The invention discloses a double-source magnetic detection system and method for local damage of a mine hoisting steel wire rope. The system comprises a shell, a magnetization loop device, a sleeve, a circumferential array type magnetic concentrator and a PC upper computer, the magnetization loop device is used for carrying out saturation magnetization on a steel wire rope, conducting a magnetic loop and efficiently utilizing magnetic energy of a magnet, and the sleeve is fixed to the shell of a detection probe, located in the center of the probe and used for installing and protecting parts in the probe. The circumferential array type magnetic gathering device is used for collecting leakage magnetic flux, weakening the circumferential conduction effect of the leakage magnetic flux in the next step and reserving circumferential positioning information of damage. The method has the beneficial effects that the influence of the main magnetic flux and the leakage magnetic flux is analyzed and detected at the same time through a double-source magnetic detection scheme, the main magnetic flux error is supplemented and corrected through the leakage magnetic flux, and the local damage detection precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of local damage detection of mining wire ropes, and in particular to a dual-source magnetic detection system and method for local damage of mining hoisting wire ropes. Background Art

[0002] Mining wire ropes are core components of mine ropeway systems and mine hoisting systems. They are bound to suffer fatigue damage to varying degrees under high-intensity working scenarios. If not detected in time, serious mine accidents may occur. At present, the on-site wire rope detection method is still mainly based on manual visual inspection due to its harsh working environment and various types of damage. The existing detection methods are roughly divided into seven categories, namely manual method, optical method, acoustic method, radiation method, mechanical method, electromagnetic method, and magnetostrictive method.

[0003] Electromagnetic detection is one of the most effective non-destructive methods for wire rope damage detection. The main magnetic flux detection method and the leakage magnetic flux detection method are typical representatives. The principle is essentially to excite the wire rope and then detect the magnetic induction intensity of the main magnetic flux signal of the wire rope or the surface leakage magnetic field signal through the sensor. However, it still cannot fully meet the requirements of quantitative detection of wire ropes.

[0004] Main magnetic flux detection is one of the most commonly used electromagnetic detection methods and is widely used in non-destructive testing of mining steel wire ropes. This method has a good effect on the detection of long-distributed damage such as wear and corrosion, but the detection accuracy is low for local broken wire damage due to its axial resolution limitation; and in the local damage detection process based on leakage magnetic flux, factors such as broken wire position, warping direction, and fracture length will cause the leakage magnetic field of the damage to behave differently, and the current quantitative detection accuracy is still not high. As a special linear flexible component, the local minimum strength of the entire rope determines the strength of the overall structure. Therefore, local damage cannot be ignored, and timely detection is the key to ensuring the safety of the wire rope in service. In order to improve the accuracy of local damage detection of mining steel wire ropes, the present invention combines the complementarity of main magnetic flux and leakage magnetic flux in local damage detection, and proposes a local damage magnetic detection system and method for mining steel wire ropes based on the combination of main magnetic flux and leakage magnetic flux. Summary of the invention

[0005] In view of the defects in the prior art, the present invention provides a dual-source magnetic detection system for local damage of mine hoisting wire ropes, which can realize high-precision quantitative detection of local damage of mine wire ropes.

[0006] In order to achieve the above technical objectives, the present invention adopts the following technical means:

[0007] A dual-source magnetic detection system for local damage of a mine hoisting wire rope comprises a sleeve coaxially arranged from the inside to the outside, a circumferential array type magnetic concentrator, a magnetizing circuit device and a shell, wherein:

[0008] The middle of the sleeve is where the wire rope passes;

[0009] The housing is installed at the outermost periphery of the probe main body structure, and the circumferential array type magnetic concentrator is installed in the permanent magnet slot of the sleeve;

[0010] The magnetizing circuit device is installed on the magnetic concentrator bracket slot of the sleeve; the magnetizing circuit device is composed of a plurality of magnetic circuit units and a permanent magnet in the center, each magnetic circuit unit includes two block magnets with opposite polarities and a long strip armature, the two block magnets with opposite polarities are respectively installed at the two ends of the long strip armature, and the permanent magnet is used to saturate magnetize the wire rope;

[0011] The strip-shaped armature includes an armature without a bridge and an armature with a bridge. The armature without a bridge forms a multi-channel first Hall element array to detect the leakage magnetic field, ensuring comprehensive perception of the leakage magnetic damage signal; the armature with a bridge forms a bridge detection to obtain the bridge magnetic flux, realizing indirect representation of the change of the main magnetic flux signal;

[0012] The circumferential array type magnetic concentrator comprises a PCB board, and the sleeve is provided with a PCB board slot for installing the PCB board; the PCB board is provided with a signal processing circuit, and the main magnetic flux signal and the leakage magnetic flux signal are processed by the signal processing circuit, and finally the signal characteristic quantity is extracted;

[0013] A PC host computer is connected to the signal processing circuit through a data acquisition unit;

[0014] The sleeve is integrally mounted in the housing.

[0015] The shell comprises a handle, a window, a limit hinge, an upper semi-annular shell unit and a lower semi-annular shell unit. The handle is fixedly connected to the outer wall of the upper semi-annular shell unit. A window for a steel wire rope to pass through is provided at the center of the shell. The upper semi-annular shell unit and the lower semi-annular shell unit are connected by a limit hinge to realize the rotation and opening and closing of the upper and lower semi-annular shell units.

[0016] The multiple magnetic circuit units are distributed in an equidistant array around the wire rope. When the number of circuits increases exponentially, the magnetization intensity of the corresponding wire rope also increases approximately exponentially. When there are 8 circuits, the magnetic induction intensity of the wire rope is 1.9079 Telsa. At this time, the wire rope has been magnetized to a saturated state and can meet the detection requirements.

[0017] The armature without a bridge circuit forms a 6-way first Hall element array to detect the leakage magnetic field; the armature with a bridge circuit forms a 2-way bridge circuit detection to detect the bridge circuit magnetic field.

[0018] The sleeve includes a permanent magnet slot, a magnetic concentrator bracket slot and a PCB board slot. The permanent magnet slots are located on both sides of the sleeve and are distributed in a circumferential array. The magnetic concentrator bracket slots are symmetrically distributed relative to the center of the sleeve, and the PCB board slot is located at the center of the sleeve.

[0019] The circumferential array type magnetic concentrator comprises a PCB board, a magnetic concentrator column and a magnetic concentrator bracket, wherein the magnetic concentrator column (4-2) is connected to the magnetic concentrator bracket slot through the magnetic concentrator bracket, the PCB board is installed on the PCB board slot, and the two magnetic concentrator brackets are connected to the PCB board through bolt connection, and the magnetic concentrator brackets are symmetrically installed relative to the PCB board.

[0020] The magnetic concentrator support comprises two semi-circular magnetic concentrator supports arranged at the upper and lower parts, and the magnetic concentrator columns of the circumferential array type magnetic concentrator are spaced 1.5 cm to 2.5 cm apart.

[0021] The signal processing circuit is composed of a bias amplifier circuit and a filter circuit. The main magnetic flux signal and the leakage magnetic flux signal are first amplified by the bias amplifier circuit, then filtered by the filter circuit, and finally the signal feature quantities of the two are respectively extracted.

[0022] A dual-source magnetic detection method for local damage of a mining steel wire rope, based on the dual-source magnetic detection system for local damage of a mining steel wire rope, comprises the following steps:

[0023] S1, magnetizing the steel wire rope to a saturation state by the permanent magnet;

[0024] S2. When the wire rope is damaged, both the main magnetic flux signal and the leakage magnetic flux signal will change. The leakage magnetic field is detected based on the multi-channel first Hall element array without the bridge armature to obtain the leakage magnetic flux characteristic quantity; at the same time, the bridge magnetic flux is obtained based on the bridge detection formed by the bridge armature, thereby indirectly representing the change of the main magnetic flux signal;

[0025] S3, extracting the signal characteristics after amplifying and filtering the magnetic signal through a signal processing circuit, wherein the leakage magnetic flux characteristics are used as a supplementary correction to the main magnetic flux;

[0026] S4. Train the fitting network model to perform inverse identification of wire rope damage.

[0027] Beneficial effects of the present invention:

[0028] 1. The present invention adopts a dual-source magnetic detection scheme, that is, simultaneously analyzes and detects the influence of the main magnetic flux and the leakage magnetic flux, and uses the leakage magnetic flux to supplement and correct the main magnetic flux error, thereby improving the accuracy of local damage detection;

[0029] 2. The present invention designs an independent separation circuit, and the magnetic circuit unit is composed of two block magnets with opposite polarities and a long strip armature; the magnets and armatures in multiple groups of circuits are arranged in an array with equal distances relative to the circumference of the wire rope, and the magnetization direction of the single-side permanent magnets is the same, both radially inward or outward along the wire rope. The magnetic fields generated by the circumferential array magnets at the center of the wire rope can also cancel each other out, and the magnetic field intensity at the axis of the wire rope on the array surface is basically zero. The solution is small in size and light in weight;

[0030] 3. The present invention designs a new type of circumferential array magnetic concentrator. The improved magnetic concentrator can realize magnetic concentrating of leakage flux signals and improve signal-to-noise ratio while retaining the circumferential positioning information of the damaged steel wire rope;

[0031] 4. The communication method of the present invention adopts a combination of ESP8266 wireless communication chip and UART asynchronous serial communication method, which can realize short-distance and long-distance accurate data transmission of the detection device in the underground environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is an axonometric diagram of the probe of the dual-source magnetic detection system for local damage of mining wire ropes of the present invention and its installation position in the lifting system;

[0033] Among them, 1. shell; 2. magnetizing circuit device; 3. sleeve; 4. circumferential array type magnetic concentrator;

[0034] Figure 2 This is the exploded view of the probe main structure;

[0035] Among them, 1-1, handle; 1-2, window; 1-3, limit hinge; 2-1, block magnet; 2-2, long strip armature; 4-1, PCB board; 4-3, magnetic concentrator bracket;

[0036] Figure 3 is the axonometric view of the sleeve;

[0037] Among them, 3-1, permanent magnet slot; 3-2, magnetic concentrator bracket slot; 3-3, PCB board slot;

[0038] Figure 4 It is a structural diagram of a circumferential array type magnetic concentrator;

[0039] Among them, 4-2, magnetic column;

[0040] Figure 5 Schematic diagram of two types of armatures of the present invention;

[0041] Figure 6 This is the principle diagram of dual-source magnetic detection;

[0042] Figure 7 It is a flow chart of the structure optimization method;

[0043] Figure 8 This is the overall structure diagram of the system hardware;

[0044] Fig. 9 This is a simulation model diagram of the magnetic bridge circuit detection of wire rope damage;

[0045] Fig.10 It is a schematic diagram of the dual-source magnetic detection scheme;

[0046] Fig.11 Figure 1 is the sensor layout diagram;

[0047] Fig.12 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0048] The present invention provides a dual-source magnetic detection system and method for local damage of mine hoisting wire rope: In the first aspect, the present invention provides a dual-source magnetic detection system for local damage of mine wire rope, and the main structure detection probe device is composed of an outer shell, a block magnet, a long armature, a permanent magnet, a sleeve, and a circumferential array type magnetic concentrator; the circumferential array type magnetic concentrator is installed on the magnetic concentrator bracket slot of the sleeve through the magnetic concentrator bracket; the PCB board is installed on the PCB board slot of the sleeve; the permanent magnet is installed in the permanent magnet slot of the sleeve; the above structures are all installed in the outer shell.

[0049] The sensor system of the present invention has 6 strands. In order to minimize the difference caused by the strand wave on the detection of each channel, the number of Hall elements needs to be an integer multiple of the strand wave. Therefore, the present invention selects a 6-way Hall element array arranged in a circle to detect the leakage magnetic field. Each sensor collects the leakage magnetic field within a range of 60° to ensure the comprehensive perception of the leakage magnetic damage signal. At the same time, the present invention selects two-way bridge detection to prevent the bridge detection error caused by damage to one of the sensors.

[0050] The signal processing circuit of the present invention is mainly composed of a bias amplifier circuit and a filter circuit; wherein the bias amplifier circuit op amp chip is required to have a higher input impedance and a lower output impedance as well as a stronger common-mode signal suppression capability. The op amp chip in this paper adopts the rail-to-rail operational amplifier AD8538 of ADI Company, which has the characteristics of low distortion, high precision, high stability and low noise, and can meet the requirements of the amplifier circuit. According to Ohm's law, the positive input voltage V in =R 4 / (R 3 +R 4 )V 0 , reverse input voltage V ref =R 5 / (R 5 +R 6 )V 0According to the concept of "virtual short" and "virtual disconnect" of the op amp, the output voltage V out for:

[0051]

[0052] In order to suppress the noise in the output signal of the amplifier circuit to the greatest extent, the Butterworth low-pass filter is selected and the low-pass filter circuit is designed with the Sallen-Key topology structure;

[0053] The transfer function of the low-pass filter function is:

[0054]

[0055] The cut-off frequency is:

[0056]

[0057] When R 1 =R 2 =R, the cut-off frequency can be simplified to:

[0058]

[0059] The quality factor of the low-pass filter circuit is:

[0060]

[0061] The cutoff frequency of the low-pass filter is 100Hz, and the capacitance value range of the filter circuit is 100nF~10μF. While ensuring the quality factor, select capacitor C1=220nF, capacitor C2=100nF, and the filter circuit resistance R is:

[0062]

[0063] A similar commonly used resistor is 10kΩ, so the final low-pass filter circuit cutoff frequency is:

[0064]

[0065] Multi-channel hardware acquisition system, the hardware platform of the wire rope damage magnetic detection system is divided into three parts, the front-end data acquisition end, the data acquisition end and the PC host end; the front-end data acquisition end will bias amplify and filter the collected data, the data acquisition end performs A / D conversion and storage of data based on STM32, and the PC host part performs real-time display and recognition processing.

[0066] The wire rope damage signal detection described in the present invention belongs to the pattern recognition problem, and the neural network has certain advantages in solving this type of problem. The present invention uses the BP (Backpropagation) neural network and trains it through the error back propagation algorithm. The calculation formula of each layer in the signal forward propagation process is: y = T (ωX + b), and the error function commonly used in the error back propagation process is:

[0067] As a further improvement of the present invention, the housing is composed of a handle, a window, and a limit hinge. The handle is fixed to the housing by interference fit and rotates synchronously with the upper half of the housing in the same direction; the window is located at the exact center of the housing wheel and is symmetrically distributed relative to the dividing line between the upper and lower parts of the housing; the limit hinge is installed on the housing by bolts, located on the right side of the housing, and is symmetrically distributed relative to the dividing line between the upper and lower parts of the housing.

[0068] As a further improvement of the present invention, the magnetizing circuit device is composed of 8 magnetic circuit units, each of which is composed of two block magnets with opposite polarities, a long strip armature in the middle and a permanent magnet. The magnetic circuit units are distributed in an equidistant array around the wire rope and are surrounded by the outer shell on the outside.

[0069] As a further improvement of the present invention, the sleeve, which is composed of a permanent magnet slot, a magnetic concentrator bracket slot and a PCB board slot, is installed on the inner side of the shell and connected to the shell with M3 bolts.

[0070] As a further improvement of the present invention, the circumferential array type magnetic concentrator is composed of a PCB board, a magnetic concentrator column and a magnetic concentrator bracket, which is installed on the magnetic concentrator bracket groove of the sleeve, and the magnetic concentrator is connected to the magnetic concentrator bracket groove of the sleeve through the magnetic concentrator bracket.

[0071] In a second aspect, the present invention also proposes a dual-source magnetic detection method for local damage of a mining wire rope, comprising the following steps:

[0072] S1. The detection method mainly determines the damage of the wire rope by detecting the change of magnetic flux. By constructing a magnetic bridge method of an auxiliary magnetic circuit, the Hall element is used to indirectly measure the change of the main magnetic flux. The magnetic flux formed on the auxiliary magnetic circuit is opposite to the magnetic flux formed in the wire rope. The auxiliary circuit is called a magnetic bridge circuit. The magnetic field strength in the gap of the magnetic bridge circuit is adjusted to the linear working range of the Hall element by adjusting the structural dimensions of the magnetic bridge circuit, the structural dimensions of the circuit, and the magnetic source parameters, so as to indirectly measure the change of the main magnetic flux of the wire rope using the output signal of the Hall element;

[0073] S2. For local LF damage, due to the influence of leakage flux, the main flux is related to both the damage degree and the damage width, so it cannot be directly calculated. Therefore, the influence of the main flux and leakage flux must be considered at the same time;

[0074] S3. When damage occurs in the wire rope, the missing ferromagnetic material at the damaged part is replaced by air gaps. The magnetic permeability of the air gaps is much lower than that of the wire rope. Therefore, the magnetic flux at the damaged part diffuses into the surrounding ferromagnetic materials, causing the magnetic field intensity in the surrounding materials to increase and the magnetic permeability to further decrease. The excess magnetic flux that cannot be contained leaks into the air. The leaked magnetic flux is detected by the magnetic sensitive element and the characteristic properties of the damage are inverted to evaluate the wire rope condition.

[0075] S4. Magnetic leakage detection mainly realizes the detection of the wire rope through the permanent magnet, armature and magnetic sensitive element. Among them, the permanent magnet acts as an excitation source to provide energy for the magnetization of the wire rope, and the armature plays the role of conducting the magnetic circuit, reducing the magnetic resistance of the circuit, and maximizing the use of magnetic energy. When designing the structure of the wire rope magnetic leakage detection circuit, it is necessary to comprehensively consider the parameters of the permanent magnet, armature, air gap and the wire rope itself to ensure that the expected excitation effect is achieved.

[0076] Please refer to Figure 1 The present invention provides a dual-source magnetic detection system for local damage of a mine hoisting wire rope, comprising a shell 1, a magnetizing circuit device 2, a sleeve 3, and a circumferential array type magnetic concentrator 4.

[0077] Please refer to Figure 2 The outermost end of the present invention is a shell structure to protect the internal parts of the probe; the inner part is the loop armature and the permanent magnet array, the polarity of the magnets on the same side is the same, and the polarity on both sides is opposite; the middle part is the sensor and its processing circuit board and the magnetic concentrator for detecting the damaged magnetic signal; the innermost part is the sleeve, and the middle of the sleeve is where the wire rope passes. The overall structure of the probe is compact, with a total weight of about 4kg, which realizes the dual-source detection method of the present invention while meeting the handheld detection requirements.

[0078] Please refer to Figure 3 The sleeve designed by the present invention has a permanent magnet slot, a magnet concentrator bracket slot, and a PCB board slot for installation and fixing. The moving wire rope passes through the inside, which can reduce the damage to the internal parts of the probe caused by the vibration of the wire rope to a certain extent. The sleeve is made of nylon material by 3D printing. Nylon has the characteristics of smooth surface, high toughness and high wear resistance, which is more suitable for the working conditions of the sleeve.

[0079] Please refer to Figure 4 The magnetic columns of the new magnetic concentrator designed by the present invention are spaced a certain distance apart. The magnetic concentrator is made of high magnetic permeability material. The magnetic concentrator bracket is used as the carrier of the magnetic concentrator column, and the upper and lower split design is adopted for easy assembly. The new magnetic concentrator can retain the function of collecting leakage magnetic flux of the traditional magnetic concentrator while weakening the circumferential conduction function of the leakage magnetic flux in the next step, thereby reducing the mutual influence between the various detection channels, thereby retaining the circumferential positioning information of the damage.

[0080] Please refer to Figure 5 There are two types of armatures: ordinary armature and armature with bridge circuit, which are used for main flux detection and leakage flux detection respectively. There are 6 ordinary armature bridge circuits and 2 armature with bridge circuits.

[0081] Please refer to Figure 6 The present invention adopts a dual-source magnetic detection method, in which the method of main magnetic flux detection is that the magnetic flux formed on the auxiliary magnetic circuit is opposite to the magnetic flux formed in the wire rope, and the auxiliary circuit is called a magnetic bridge circuit. By adjusting the structural dimensions of the magnetic bridge circuit, the structural dimensions of the circuit, and the magnetic source parameters, the magnetic field strength in the gap of the magnetic bridge circuit is adjusted to the linear working range of the Hall element, so that the output signal of the Hall element is used to indirectly measure the change of the main magnetic flux of the wire rope. The change of the output voltage in the Hall element in the magnetic bridge circuit can linearly characterize the reduction of the effective metal area caused by the damage of the wire rope; the main components of the wire rope leakage magnetic detection are: wire rope, permanent magnet, armature, and magnetic sensitive element. Among them, the permanent magnet acts as an excitation source to provide energy for the magnetization of the wire rope, and the armature plays the role of conducting the magnetic circuit, reducing the magnetic resistance of the circuit, and maximizing the use of magnetic energy. When designing the structure of the wire rope leakage magnetic detection circuit, it is necessary to comprehensively consider the parameters of the permanent magnet, armature, air gap and the wire rope itself to ensure that the expected excitation effect is achieved.

[0082] For the optimization method of the structure, please refer to Figure 7 , the main flux detection resolution problem is analyzed by finite element simulation. First, a simulation project is created and the type of problem to be solved is defined; then the corresponding model is established and the corresponding materials and properties are assigned to each part; then the excitation source and boundary conditions are set and the established model is reasonably meshed; finally, the solution parameters are set, that is, the simulation step size and time, and the model can be solved. After the results are obtained, post-processing is performed as needed to view the results, and compared with the theory to verify the accuracy of the simulation; if the simulation results are inaccurate, it is necessary to continuously adjust the model materials and dimensions, boundary conditions, mesh and other parameters until the simulation and theory are relatively consistent.

[0083] Please refer to Figure 8 The hardware platform of the wire rope damage magnetic detection system is divided into three parts: the front-end data acquisition end, the data collection end and the PC host end; the front-end data acquisition end performs bias amplification and filtering on the collected dual-source magnetic detection data, the data collection end performs A / D conversion and storage of the data based on STM32, and the PC host part performs real-time display and recognition processing.

[0084] Please refer to Fig. 9The figure shows the established two-dimensional simulation model of wire rope damage. The excitation source is N52 NdFeB magnet, the coercive force of the magnet is set to 955KA·m-1, the remanence is set to 1.45T, the magnetization direction is perpendicular to the axis of the wire rope, the polarities of the magnets on the left and right sides are opposite, the unit vector of the left magnet Y Component is -1, and the unit vector of the right side is 1. The armature and the constructed bridge circuit are selected from the electrical pure iron model Steel_1008.

[0085] Please refer to the dual source magnetic detection solution Fig.10 First, the front-end exciter magnetizes the wire rope to a saturated state. When the wire rope is damaged, both the main magnetic flux signal and the leakage magnetic flux signal will change. Based on the magnetic sensitive element array, the leakage magnetic flux change is detected, and a magnetic bridge is constructed to obtain the bridge magnetic flux, thereby indirectly representing the change of the main magnetic flux signal; then, the magnetic signal is amplified and filtered, and its signal characteristics are extracted respectively, among which the leakage magnetic flux characteristic is used as a supplementary correction to the bridge magnetic flux characteristics; finally, the training fitting network model is used for inverse identification of wire rope damage.

[0086] For sensor layout, please refer to Fig.11 In order to minimize the difference caused by the wave on each channel detection, the number of Hall elements needs to be an integer multiple of the wave. Considering that 12 channels will make the subsequent processing circuit complicated and is not conducive to the simplification of the circuit board size and the overall probe, and the magnetic concentrator designed in the previous article can increase the detection range of the Hall element in the circumferential direction, this paper chooses a 6-way Hall element array arranged in a circle to detect the leakage magnetic field. Each sensor collects the leakage magnetic field within a range of 60° to ensure the comprehensive perception of the leakage magnetic damage signal. The spatial distribution of the bridge magnetic field itself is relatively concentrated, and a single channel can detect the complete bridge magnetic field. This paper selects two-way bridge detection to prevent the bridge detection error caused by damage to one of the sensors. In actual detection, one of the data can be selected.

[0087] Please refer to Fig.12 The present invention obtains abnormal signals generated by various damages of the wire rope through dual-source magnetic detection, and obtains the precise state of the wire rope during work through signal collection and processing, and monitors and uploads the local damage of the mine hoisting wire rope in real time.

[0088] The present invention also provides a method for magnetically detecting local damage of a mining steel wire rope, comprising the following steps:

[0089] S1. The steel wire rope is made of ferromagnetic material. The magnetic permeability of the ferromagnetic material in the rope is much greater than that of the air. When the steel wire rope is magnetized by an external excitation source, the magnetic flux will be retained inside the steel wire rope; when the steel wire rope is damaged, the internal magnetic flux of the steel wire rope will change its initial state and generate a measurable leakage magnetic field around it. The process of detecting the change of the internal magnetic flux or leakage magnetic field is the main magnetic flux detection and leakage magnetic flux detection of the steel wire rope respectively;

[0090] S2. When the wire rope is damaged, both the main magnetic flux signal and the leakage magnetic flux signal will change. The leakage magnetic flux change is detected based on the magnetic sensitive element array, and a magnetic bridge circuit is constructed to obtain the bridge magnetic flux, thereby indirectly representing the change of the main magnetic flux signal.

[0091] S3, extracting the signal characteristics after amplifying and filtering the magnetic signal, wherein the leakage flux characteristic is used as a supplementary correction to the bridge flux characteristic;

[0092] S4. Train the fitting network model to perform inverse identification of wire rope damage.

[0093] The embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, but the present invention is not limited thereto. Various changes that can be made within the knowledge scope of technicians in the relevant technical field without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. A dual-source magnetic detection system for local damage of mine hoisting wire rope, characterized in that: It comprises a sleeve (3) coaxially arranged from the inside to the outside, a circumferential array type magnetic concentrator (4), a magnetizing circuit device (2) and a housing (1), wherein: The middle of the sleeve (3) is where the steel wire rope passes; The housing (1) is installed at the outermost part of the probe main body structure, and the circumferential array type magnetic concentrator (4) is installed in the permanent magnet slot (3-1) of the sleeve (3); The magnetizing circuit device (2) is mounted on the magnetic concentrator bracket slot (3-2) of the sleeve (3); the magnetizing circuit device (2) is composed of a plurality of magnetic circuit units and a central permanent magnet (2-3), each magnetic circuit unit comprises two block magnets (2-1) with opposite polarities and a long strip armature (2-2), the two block magnets (2-1) with opposite polarities are respectively mounted at the two ends of the long strip armature (2-2), and the permanent magnet is used to saturate magnetize the steel wire rope; The strip-shaped armature (2-2) includes an armature without a bridge and an armature with a bridge. The armature without a bridge forms a multi-path first Hall element array to detect the leakage magnetic field, thereby ensuring comprehensive perception of the leakage magnetic damage signal; the armature with a bridge forms a bridge detection to obtain the bridge magnetic flux, thereby realizing indirect representation of the change of the main magnetic flux signal. The circumferential array type magnetic concentrator (4) comprises a PCB board (4-1), and the sleeve (3) is provided with a PCB board slot (3-3) for mounting the PCB board (4-1); a signal processing circuit is provided on the PCB board (4-1), and a main magnetic flux signal and a leakage magnetic flux signal are processed by the signal processing circuit, and finally a signal characteristic quantity is extracted; A PC host computer (5) is connected to the signal processing circuit through a data acquisition unit; The sleeve (3) is integrally mounted in the housing (1).

2. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 1 is characterized in that: The housing (1) comprises a handle (1-1), a window (1-2), a limit hinge (1-3), an upper semi-annular housing unit (1-4) and a lower semi-annular housing unit (1-5); the handle (1-1) is fixedly connected to the outer wall of the upper semi-annular housing unit (1-4); a window (1-2) for a steel wire rope to pass through is provided at the center of the housing; the upper semi-annular housing unit (1-4) and the lower semi-annular housing unit (1-5) are connected by the limit hinge (1-3) to realize the rotation and opening and closing of the upper and lower semi-annular housing units.

3. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 1 is characterized in that: The multiple magnetic circuit units are distributed in an equidistant array around the wire rope. When the number of circuits increases exponentially, the magnetization intensity of the corresponding wire rope also increases approximately exponentially. When there are 8 circuits, the magnetic induction intensity of the wire rope is 1.9079 Telsa. At this time, the wire rope has been magnetized to a saturated state and can meet the detection requirements.

4. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 1 is characterized in that: The armature without a bridge circuit forms a 6-way first Hall element array to detect the leakage magnetic field; the armature with a bridge circuit forms a 2-way bridge circuit detection to detect the bridge circuit magnetic field.

5. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 1 is characterized in that: The sleeve (3) comprises a permanent magnet slot (3-1), a magnetic concentrator bracket slot (3-2) and a PCB board slot (3-3); the permanent magnet slot (3-1) is located on both sides of the sleeve (3) and is distributed in a circumferential array; the magnetic concentrator bracket slot (3-2) is symmetrically distributed relative to the center of the sleeve (3); and the PCB board slot (3-3) is located at the exact center of the sleeve (3).

6. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 1 is characterized in that: The circumferential array type magnetic concentrator (4) comprises a PCB board (4-1), a magnetic concentrator column (4-2) and a magnetic concentrator bracket (4-3), wherein the magnetic concentrator column (4-2) is connected to the magnetic concentrator bracket slot (3-2) via the magnetic concentrator bracket (4-3), the PCB board (4-1) is installed on the PCB board slot (3-3), and the two magnetic concentrator brackets (4-3) are connected to the PCB board (4-1) by bolt connection, and the magnetic concentrator bracket (4-3) is symmetrically installed relative to the PCB board (4-1).

7. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 6 is characterized in that: The magnetic concentrator support (4-3) comprises two semi-circular magnetic concentrator supports arranged at the top and the bottom, and the distance between the magnetic concentrator columns of the circumferential array type magnetic concentrator (4) is 1.5 cm to 2.5 cm.

8. The dual-source magnetic detection system for local damage of mine hoisting wire rope according to claim 6 is characterized in that: The signal processing circuit is composed of a bias amplifier circuit and a filter circuit. The main magnetic flux signal and the leakage magnetic flux signal are first amplified by the bias amplifier circuit, then filtered by the filter circuit, and finally the signal feature quantities of the two are respectively extracted.

9. A dual-source magnetic detection method for local damage of a mining steel wire rope, based on the dual-source magnetic detection system for local damage of a mining steel wire rope according to any one of claims 1 to 8, characterized in that: The steps include: S1, magnetizing the steel wire rope to a saturation state by the permanent magnet; S2. When the wire rope is damaged, both the main magnetic flux signal and the leakage magnetic flux signal will change. The leakage magnetic field is detected based on the multi-channel first Hall element array without the bridge armature to obtain the leakage magnetic flux characteristic quantity; at the same time, the bridge magnetic flux is obtained based on the bridge detection formed by the bridge armature, thereby indirectly representing the change of the main magnetic flux signal; S3, extracting the signal characteristics after amplifying and filtering the magnetic signal through a signal processing circuit, wherein the leakage magnetic flux characteristics are used as a supplementary correction to the main magnetic flux; S4. Train the fitting network model to perform inverse identification of wire rope damage.

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