An embedded fracture detection label, a mine chain fracture monitoring system, a fracture detection and early warning method and a chain

Abstract

An embedded fracture detection tag, a mining chain fracture monitoring system, a fracture detection and early warning method, and a chain are disclosed. The detection tag includes a dielectric substrate with a flexible structure; an antenna radiator attached to the surface of the dielectric substrate in a closed-loop shape, with at least two mechanically weak points; an RF chip electrically connected to the antenna radiator; and an encapsulation layer covering the dielectric substrate, antenna radiator, and RF chip. The antenna radiator has at least two mechanically weak points. This invention integrates a wireless sensing unit with the chain link structure, enabling direct sensing of the chain link's structural integrity. Through multi-sensor redundancy design, neighborhood verification, and multi-source data fusion for operational condition verification, interference is eliminated. Based on the gradual change in tag signal characteristics, microscopic damage to the chain link can be identified in advance. The device has strong environmental adaptability, minimal impact on chain performance, and significant economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of mining machinery monitoring technology, specifically relating to an embedded fracture detection tag, a mining chain fracture monitoring system, a fracture detection and early warning method, and a chain. Background Technology

[0002] Mining scraper conveyors are core equipment in underground coal mine transportation systems. Their traditional compact metal chains are prone to sudden breakage under extreme working conditions. According to statistics from the China Coal Industry Association, chain link breakage failures account for more than 30% of equipment failures in underground scraper conveyors, with an average downtime of over 19 hours for repair, severely impacting coal mining efficiency.

[0003] The existing technology has the following drawbacks:

[0004] 1. Manual inspection: High rate of missed detection, unable to monitor in real time;

[0005] 2. Tension / speed sensor: Indirectly infers the chain condition, but is greatly affected by load fluctuations and its accuracy is unstable;

[0006] 3. Vibration sensor: Strong downhole vibration interference reduces accuracy;

[0007] 4. Fiber optic sensors: high cost, complex installation, and high failure rate in downhole environments;

[0008] 5. External Radio Frequency Identification Tags (hereinafter referred to as RFID): They are difficult to attach to metal / composite material surfaces, have a high tag detachment rate, and cannot detect damage inside the chain links.

[0009] The core issue is that existing technologies all employ an "external monitoring, indirect inference, and difficult maintenance" model, which fails to achieve direct perception of the integrity of the chain link structure. There is an urgent need for a novel monitoring solution that can be embedded within the chain, formed together with the chain link body, and directly perceive the integrity of the chain link structure. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide an embedded fracture detection tag, a mining chain fracture monitoring system, a fracture detection and early warning method, and a chain. By designing the RFID tag antenna as a sensitive closed loop coupled with the force path of the fiber composite material chain FRPRLC, and combining multi-sensitive area redundancy design, multi-source data fusion, and progressive damage identification algorithm, the invention achieves rapid alarm, accurate location, and early damage warning for FRPRLC fracture of the fiber composite material chain.

[0011] The technical solution adopted in this invention is:

[0012] An embedded fracture detection tag includes:

[0013] The dielectric substrate employs a flexible structure.

[0014] The antenna radiator is attached to the surface of the dielectric substrate, is in a closed-loop shape, and has at least two mechanically weak points.

[0015] The radio frequency chip is electrically connected to the antenna radiator;

[0016] The encapsulation layer covers the dielectric substrate, antenna radiator, and radio frequency chip.

[0017] A mining chain breakage monitoring system, comprising:

[0018] Sensing layer: Multiple embedded breakage detection tags are embedded one-to-one inside each link of the scraper conveyor chain;

[0019] Acquisition layer: Multiple fixed readers are distributed and installed at predetermined positions on the scraper conveyor to periodically read tag IDs and collect the tag's signal characteristic parameters;

[0020] Transport layer: Mining gateway, which communicates with each reader / writer;

[0021] Platform layer: Monitoring center, which communicates with the gateway and is used to receive and process data. The monitoring center also collects the operating parameters of the scraper conveyor synchronously.

[0022] A method for detecting and warning of chain breakage in mining applications, comprising the following steps:

[0023] S1. Establish a chain-tag mapping table to record the reference signal characteristic parameters of each tag;

[0024] S2. Real-time monitoring: The reader continuously reads the tag ID and collects the tag's signal characteristic parameters, while simultaneously collecting the scraper conveyor's operating parameters.

[0025] S3. Fracture event determination: Based on multi-source data fusion judgment of tag existence status, neighboring tag status and equipment operating parameters;

[0026] S4. Progressive damage warning: a damage index is constructed based on the changes in the characteristic parameters of the tag signal. When the damage index exceeds a preset threshold, a warning is issued.

[0027] S5. Location and Alarm.

[0028] A mining chain, wherein embedded breakage detection tags are embedded in the links of the chain.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. Direct perception of structural integrity: By integrating the wireless sensing unit with the chain structure, a leap from "indirect inference" to "direct perception" is achieved;

[0031] 2. High reliability: Through multi-sensitive area redundancy design, neighborhood verification, and operational condition verification, interference is effectively eliminated;

[0032] 3. Early warning capability: By monitoring the gradual changes in the characteristic parameters of the tag signal, microscopic damage to the chain links can be detected in advance;

[0033] 4. Strong environmental adaptability: Circularly polarized antenna and dynamic anti-collision algorithm ensure high readout rate under high-speed chain movement and complex posture;

[0034] 5. Maintenance-free design: The tag is fully embedded and has the same lifespan as the chain link;

[0035] 6. Minimal impact on the substrate's performance: The implantation process is compatible with composite material molding processes;

[0036] 7. Significant economic benefits: Taking a coal mine with an annual output of 5 million tons as an example, adopting this system can reduce downtime losses caused by chain break accidents by about 2 million yuan per year, with an investment payback period of less than 6 months. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the detection tag structure of the present invention;

[0038] Figure 2 This is a schematic diagram of the design of the sensitive fracture zone in the detection tag of the present invention;

[0039] Figure 3 This is a graph showing the relationship between the antenna breaking force and the chain link breaking force in this invention.

[0040] Figure 4 This is a block diagram of the mining chain breakage monitoring system of the present invention;

[0041] Figure 5 This is a flowchart of the fracture detection and early warning method of the present invention;

[0042] Figure 6 This is a graph showing the relationship between the comprehensive damage index and the degree of chain link damage in this invention.

[0043] Figure 7 This is a schematic diagram of the layout and positioning of the distributed reader / writer in this invention;

[0044] Figure 8 This is a schematic diagram of the conductivity anisotropy of the fiber composite antenna radiator in this invention;

[0045] Figure 9This is a flowchart of the prefabrication and embedding process of the functional units of the present invention;

[0046] Figure 10 This is a schematic diagram of the evolution of the comprehensive damage index and early warning in this invention;

[0047] Figure 11 This is a schematic diagram of the label of the present invention being embedded in the chain link;

[0048] Figure 12 This is a process flow diagram of the label of the present invention being embedded in the fiber composite material chain link;

[0049] Wherein: 101, dielectric substrate; 102, antenna radiator; 103, radio frequency chip; 104, encapsulation layer. Detailed Implementation

[0050] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0051] This invention provides an embedded passive RFID fracture detection tag for fiber composite material chains (FRPRLC) of mining scraper conveyors, a monitoring system containing the tag, and a fracture detection and early warning method thereof.

[0052] The core of this invention lies in the coupling design of embedded RFID tags and the force path of fiber composite material chains (hereinafter referred to as FRPRLC) to achieve the dual online synchronous function of "early damage warning + real-time fracture alarm", rather than the post-event alarm of traditional technology.

[0053] 1. Mechanical design enables early detection.

[0054] By precisely aligning the label's sensitive fracture zone with the expected fracture hazard area of ​​the FRPRLC, and through material selection and geometric optimization, the label's fracture force (Fant) is made significantly smaller than the FRPRLC's fracture force (Fc) (safety margin ≥10%). When microscopic damage occurs within the FRPRLC (such as matrix cracking or fiber microcracks), the stress concentration caused by the damage will cause the sensitive fracture zone to reach the fracture threshold first, leading to premature label disconnection or impedance detuning, thus providing an early warning before the FRPRLC macroscopically fractures.

[0055] 2. Correlation between damage evolution and signal characteristics.

[0056] Tag failure is directly related to the internal damage evolution of FRPRLCs. For example, in FRPRLCs made of fiber composite materials, the conductive pathways of the tag are sensitive to fiber breakage. When the matrix of the FRPRLC cracks, the cracks propagate along the fiber interface, cutting off the transverse conductive pathways of the antenna and causing gradual changes in tag signal characteristics (such as readout power threshold and resonant frequency). This invention constructs a comprehensive damage index to quantitatively assess the degree of microscopic damage and achieve early warning.

[0057] 3. Full-cycle monitoring coverage.

[0058] From the gradual changes in microscopic damage to the abrupt changes in macroscopic fracture, this invention enables full lifecycle monitoring of the structural integrity of FRPRLCs:

[0059] Early warning stage: The tag signal characteristic parameters deviate, and the comprehensive damage index exceeds the warning threshold, indicating the need for preventive maintenance;

[0060] Breakage alarm stage: The tag is physically broken, and the reader cannot read it continuously. Based on the multi-source data fusion judgment, an emergency shutdown is triggered.

[0061] This design completely changes the traditional "post-event alarm" mode, providing key technical support for predictive maintenance of compact chains in mining scraper conveyors.

[0062] Technical solution

[0063] ① A tag for pre-embedded, embedded RFID for fracture detection during the molding stage of fiber composite materials, such as Figure 1 As shown, the label includes:

[0064] Dielectric substrate 101: A flexible material made of high-temperature resistant flexible film material (such as polyimide film) with a thickness of 0.05~0.15mm (preferably 0.1mm), which can withstand the high temperature of fiber composite material curing process (usually 120°-180°).

[0065] Antenna radiator 102: Attached to the surface of dielectric substrate 101, in the shape of an elliptical ring closed loop, with at least two symmetrically arranged mechanically weak parts on the antenna radiator, namely sensitive fracture areas. The line width of the sensitive fracture area is 0.2~0.5mm, the length is 3~8mm, and the geometric center of the sensitive fracture area coincides with the center of the expected fracture danger area of ​​the chain link, with a positioning error ≤±1mm.

[0066] Radio frequency chip 103: electrically connected to the antenna radiator 102, preferably a passive UHF RFID chip conforming to the EPC Global C1G2 standard, supporting read power threshold feedback function;

[0067] Encapsulation layer 104: Completely covers the dielectric substrate 101, antenna radiator 102 and radio frequency chip 103, and is made of high-temperature epoxy resin compatible with the chain link body, with a thickness of 0.3mm.

[0068] Key mechanical design: To ensure that the antenna will inevitably be destroyed when the chain links break, the fracture force of the antenna radiator is... satisfy:

[0069]

[0070] in, Fracture stress of antenna material (copper foil: ; Fiber composite material: 150 MPa), Minimum cross-sectional area of ​​the sensitive fracture zone, For the chain link breaking force By optimizing materials and geometry, Ensure a safety margin. For example... Figure 3 As shown.

[0071] The fracture strength of the sensitive fracture zone is lower than that of the chain link body.

[0072] Preferably, the antenna radiator 102 comprises multiple miniature sensitive fracture zones connected in series, distributed along the FRPRLC critical section direction. Fracture in any of these sensitive fracture zones causes impedance detuning or an open circuit in the antenna radiator 102, preventing it from being properly identified by the reader, thereby increasing the probability of capturing cracks at any location.

[0073] As a further preferred embodiment, the antenna radiator 102 is directly made of fiber composite material, and its longitudinal conductivity is... lateral conductivity ,like Figure 8 As shown, the fibers are arranged along the length of the fractured region (e.g.) Figure 2 As shown, an electrical bottleneck is formed in the sensitive fracture zone. When the FRPRLC fractures, the crack propagates along the fiber interface, cutting off the transverse conductive path, causing a dramatic change in antenna impedance, thus enabling damage sensing.

[0074] ② A compact chain breakage monitoring system for mining, such as Figure 4 As shown, the system includes:

[0075] Sensing layer: Multiple embedded breakage detection tags (RFID tags) as described above are embedded one-to-one within each FRPRLC of the scraper conveyor compact chain;

[0076] Data Acquisition Layer: Multiple fixed readers are distributed and installed at predetermined positions in the middle trough of the scraper conveyor (such as at the head, tail, and middle trough positions). Each reader includes an intrinsically safe mining host and a circularly polarized directional antenna to overcome the influence of attitude changes during chain movement. The readers have passed the National Coal Mine Safety Certification and comply with GB 3836.1-2021 and GB 3836.4-2021 explosion-proof standards. The readers incorporate a dynamic frame time-slot Aloha anti-collision algorithm, which dynamically adjusts the frame length parameter Q (Q value range 4~8) according to the number of tags in the identification area, ensuring a read rate ≥99.9% in high-density tag environments. The readers periodically emit radio frequency energy at a frequency of 1~10Hz and read RFID tags passing through their antenna coverage area, recording the read power threshold for each tag. Backscattered signal intensity and signal phase And upload the data in real time;

[0077] Transmission layer: Mining explosion-proof and intrinsically safe gateway, connected to each reader via an industrial bus, used for data aggregation and remote communication;

[0078] Platform Layer: Ground monitoring center, including data servers and a monitoring and early warning platform, communicates with the gateway via industrial Ethernet or a wireless network. The monitoring center also simultaneously collects the motor operating current of the scraper conveyor. Data is used for multi-source data fusion and verification.

[0079] ③ A method for detecting and warning of compact chain breakage in mining based on the above system, such as... Figure 5 As shown, the method includes the following steps:

[0080] Step S1: Initialization and Calibration

[0081] During the initial installation of the chain, all embedded tags are read using a reader / writer. Recorded as Simultaneously record the physical location corresponding to each ID. (e.g., "the i-th link from the head"), establish a link-tag mapping table. Additionally, record the baseline read power threshold for each tag in its health state. and reference resonant frequency It is stored in the database of the ground monitoring center.

[0082] Step S2: Real-time monitoring and multi-dimensional data collection

[0083] When the scraper conveyor is running, the distributed readers continuously transmit radio frequency signals at fixed intervals (e.g., 5Hz) to wake up tags that enter their identification area. The readers not only read the tag IDs but also record the reading power threshold for each tag. The system measures the backscattered signal strength and phase. The reader uploads the read ID sequence, signal parameters, and timestamp to the monitoring center in real time. Simultaneously, the system collects the motor operating current of the scraper conveyor. data.

[0084] Step S3: Fracture Event Determination

[0085] The monitoring center processes the uploaded data in real time.

[0086] Multi-source data fusion judgment is performed based on tag existence status, neighboring tag status, and device operating parameters.

[0087] Define the label existence state function :

[0088]

[0089] A chain link is determined if and only if all of the following conditions are met. Fracture occurred:

[0090] 1. Continuous loss: Tag In continuous One read cycle ( None of the contents were read;

[0091] 2. Neighborhood verification: The neighboring tags located before and after the broken chain link i (e.g., It is read normally within this time window to rule out reader malfunction or local electromagnetic interference;

[0092] 3. Operating condition verification: synchronously monitored motor current values If a characteristic change occurs within a short window (e.g., 0.5 seconds) after the tag is lost, the characteristic change is used to extract the singularity features of the current signal through wavelet transform, or to determine whether the current mutation rate exceeds a preset range through threshold comparison, so as to identify the current fluctuation pattern associated with the chain break event.

[0093] Step S4: Progressive Damage Early Warning

[0094] When the tag is read normally, early warning can be achieved by analyzing its signal characteristics.

[0095] Define the normalized power threshold offset:

[0096]

[0097] Define the normalized frequency offset:

[0098]

[0099] Construct a comprehensive damage index :

[0100]

[0101] in, The resonant frequency, These are weighting coefficients that can be adaptively adjusted based on the chain type and operating conditions. For example, under heavy load conditions, where signal fluctuations are significant, they can be appropriately reduced. The weighting factor is adjusted to reduce false alarms and improve sensitivity under light load conditions. In this embodiment, the system automatically adjusts the weighting factor based on the real-time monitored current variance.

[0102] like Figure 6 As shown, set the early warning threshold. Alarm threshold .when When the system determines that link i has microscopic damage (such as matrix cracking or local delamination), it issues a "link damage warning" and prompts preventative maintenance to be arranged; when At that time, in conjunction with the fracture determination logic in step S3, a "fracture alarm" is issued.

[0103] Step S5: Location and Alarm

[0104] Once a break in chain link i is detected, the monitoring center determines the precise location of the broken chain link (positioning accuracy ±0.8 chain links) based on the mapping table established in step S1, triggering a tiered alarm. Alarm information includes the location of the broken chain link, the time of breakage, and the current chain speed. Simultaneously, the monitoring center outputs a stop signal to the combination switch, urgently halting the scraper conveyor.

[0105] A mining chain, wherein the aforementioned embedded fracture detection tag is embedded in the chain links.

[0106] Explanation of chip temperature resistance

[0107] To address the survival issue of RFID chips during high-temperature curing processes of composite materials, this invention provides the following implementation scheme:

[0108] Option 1: Select a high-temperature resistant RFID chip that can withstand the curing process temperature. Testing showed a survival rate of 98.5% under 180℃ curing conditions, with electrical performance degradation of <5% after curing.

[0109] Option 2: Adopt a step-by-step process of "curing first and then implanting". After the chain links are cured, a cavity is formed in the preset position through secondary processing, the label is implanted and sealed with matching packaging material.

[0110] Option 3: Use a low-temperature curing resin system to reduce the curing temperature to a range that the chip can tolerate (e.g., ≤120℃), while optimizing the layup design to ensure that the mechanical properties of the chain links meet the requirements.

[0111] Security Certification

[0112] The reader / writer has passed the national coal mine safety certification and complies with the explosion-proof standards GB 3836.1-2021 and GB 3836.4-2021. The tag adopts intrinsically safe design, meeting the requirements for use in underground coal mines.

[0113] Beneficial effects

[0114] Compared with the prior art, the present invention has the following significant advantages:

[0115]

[0116] Example 1: RFID tag structure design with redundant sensitive areas

[0117] The RFID tag structure in this embodiment is as follows: Figure 2 , Figure 3 As shown. The dielectric substrate 101 is made of a 0.1 mm thick polyimide film (temperature resistant to 220℃). The antenna radiator 102 is a fiber composite material (T700 grade carbon fiber / epoxy resin), with fibers arranged longitudinally and a sensitive fracture zone linewidth. ,length To improve the sensitivity and reliability of RFID tag damage detection, such as Figure 11 As shown, a pair of mechanically sensitive fracture zones are symmetrically arranged at both ends of the major axis of the elliptical ring antenna radiator enclosed by RFID tags. With the RFID tag embedded within the fiber chain link body, precise alignment ensures a dual, precise coupling of spatial and mechanical paths between the RFID tag's sensitive fracture zone and the inherent maximum stress concentration area in the middle of the fiber chain link's straight edge. Based on this design, stress abrupt changes or microcrack propagation generated during service in the fiber chain link will directly act on the RFID tag's sensitive zone, causing the RFID tag's antenna radiator to experience impedance detuning or physical fracture preferentially over the fiber chain link body. This, through the interruption and gradual change of the RFID tag's radio frequency signal, enables early warning of damage to the fiber chain link structure and real-time alarm at the moment of fracture, ensuring no omissions in detection.

[0118] Two symmetrically positioned sensitive fracture zones constitute a parallel failure mechanism. When a crack initiates in either critical section (such as the middle of a straight edge or a rounded transition zone), at least one sensitive fracture zone will break before the crack propagates to a critical size, resulting in an open circuit in the antenna. This design increases the crack capture probability from approximately 70% for a single sensitive zone to over 95%. The RF chip 103 preferably uses an Impinj Monza R6-P chip, supporting automatic feedback of the readout power threshold. The encapsulation layer 104 is made of high-temperature epoxy resin with a thickness of 0.3 mm.

[0119] Tests showed the antenna resonant frequency to be 922.5MHz, radiation efficiency to be 58%, and readout distance to be 3.2m (actual measurement, transmit power). Antenna breaking force It is much smaller than the chain link breaking force of 220kN, ensuring that the antenna will definitely break when the chain link breaks.

[0120] Example 2: Implantation process and mechanical performance verification

[0121] like Figure 9 , Figure 12 As shown, this embodiment describes in detail the entire process of accurately locating and embedding RFID tags inside fiber composite material chain links.

[0122] 1. Prefabricated "functional units"

[0123] In a clean environment, standardized functional units are prefabricated:

[0124] Material preparation: High-temperature resistant polyimide film ( The dielectric substrate 101 is made of a 0.1 mm thick carbon fiber / epoxy resin prepreg (single layer thickness 0.15 mm). The antenna radiator 102 is selected as a candidate material.

[0125] Antenna forming: Prepreg is cut into a pre-set elliptical ring antenna shape using a precision mold, and the fiber orientation of the sensitive fracture area of ​​the antenna is strictly aligned longitudinally.

[0126] Unit packaging: The formed antenna radiator 102 and RF chip 103 are placed between two thin layers of glass fiber prepreg (serving as a dielectric isolation layer and positioning carrier, with a thickness of approximately 0.1 mm). A micro-clearance groove is pre-drilled at the chip's location. The thickness of the glass fiber prepreg layer is designed based on the quarter-wavelength impedance matching principle. Subsequently, a low-hardness silicone roller is used for pre-compactment, forming a uniformly thick and structurally stable "functional unit".

[0127] 2. Dry layup and precise positioning of functional units

[0128] Base layup: Within the chain link forming mold, the fiber prepreg is wound according to design requirements. The winding is paused at a predetermined depth (e.g., the 5th layer), chosen close to the neutral layer of the laminate.

[0129] Groove Preparation and Filling: At the predetermined embedding location, the outline of the chip package is precisely projected onto the layup surface using a laser projector. An operator uses a specialized tool to gently press shallow grooves into the fiber prepreg. The groove shape is preferably circular or rectangular with large rounded corners (corner radius ≥ 1 mm). A WF71 foam disc (preferably Rohacell®) matching the groove shape is pre-embedded within the groove. This foam provides uniform support and cushioning for the chip during subsequent curing.

[0130] Functional unit positioning: Using micro positioning pins on the mold or a vision guidance system, the prefabricated "functional unit" is precisely aligned and placed on the ply surface to ensure that the geometric center of its sensitive fracture zone coincides with the center of the maximum stress zone in the middle of the straight edge of the chain link, with the error controlled within ±1mm.

[0131] Temporary fixation: Low-viscosity, high-temperature volatile silicone dots or special positioning adhesive film are used to fix the functional unit in dots around its edges.

[0132] 3. Leapfrog tiling and interface transition processing

[0133] Flexible transition: At the junction of the functional unit edge and the fiber layer, a thin strip of soft silicone rubber is manually laid to form a smooth load transfer transition zone.

[0134] Leap-over layup: Continue winding the remaining fiber prepreg using a "leap-over" gentle layup, and do not drag along the unit surface.

[0135] 4. Co-curing molding

[0136] Vacuum bag sealing: Perform standard vacuum bag sealing procedures to ensure no bridging and no wrinkles.

[0137] Autoclave curing: Co-curing is performed according to the epoxy resin curing cycle (180℃, 0.6MPa pressure, 2 hours) to ensure a firm bond between the fiber layer, functional units, and Rohacell foam.

[0138] 5. Post-processing and quality inspection

[0139] Demolding and trimming.

[0140] Non-destructive testing: Ultrasonic C-scan was used to inspect the interface bonding quality. The results showed that the interface bonding strength was ≥28MPa and there were no obvious defects such as delamination.

[0141] Mechanical performance verification: Tensile strength test was conducted according to GB / T 228.1-2021. After the tag was implanted, the tensile strength of the chain link decreased by 2.8% (original strength 235kN, 228.5kN after implantation), which meets the usage requirements.

[0142] Example 3: Fracture Detection Based on Multi-Source Data Fusion

[0143] This embodiment describes in detail the following: Figure 5 The breakage detection logic is shown. The reader operates at a frequency of 10Hz, and the chain speed is 1.5m / s. For the chain link... The monitoring center maintains its status queue. Assuming that in... At that moment, it was detected :

[0144] Logic 1 (Continuous Loss): Backtracking the historical state, if it is found that 5 consecutive cycles (i.e. 0.5 seconds) are all 0, then it is added to the candidate break list.

[0145] Logic 2 (Neighborhood Verification): Check the neighbor labels of candidate broken chain i. The read status within the same time period. If the neighbor tag read is normal. This eliminates the possibility of a localized fault in the reader antenna.

[0146] Logic 3 (Operating Condition Verification): Obtain the motor current signal from the centralized control system, extract the singularity features of the current signal through wavelet transform, and if a feature change related to the chain break event is detected (such as the current mutation rate exceeding the preset threshold), then all three conditions are met, and the system finally confirms that the chain link i has broken, triggering an emergency stop alarm.

[0147] In the simulated chain break test, the average time from the occurrence of chain break to the alarm was 0.42 seconds, and the positioning accuracy was ±0.8 chain links.

[0148] Example 4: Early Warning Based on Comprehensive Damage Index

[0149] This embodiment corresponds to Figure 6 During the normal tag reading phase, the system continuously calculates the comprehensive damage index. The warning threshold was calibrated through laboratory fatigue tests. The corresponding micro-damage state is a 5% decrease in the stiffness of the chain links; alarm threshold. The corresponding chain links show severe damage with visible cracks.

[0150] Weighting coefficients It can adaptively adjust according to the chain type and operating conditions. For example, under heavy load conditions (large current fluctuations), the system automatically reduces the current variance based on real-time monitoring. The value is adjusted to 0.4 / 0.3 to reduce false alarms; under light load conditions, the sensitivity is restored to the normal level of 0.6 / 0.4.

[0151] During a downhole test, the system detected a certain link in the chain. The value slowly increased from 0.1 to 0.35 over three consecutive days, triggering a "chain link damage warning." Maintenance personnel then conducted ultrasonic testing on the chain links in that area, discovering minute internal delamination defects. The chain links were promptly replaced, preventing a potential chain breakage accident.

[0152] Example 5: Distributed Reader and Writer with Dynamic Collision Avoidance

[0153] This embodiment corresponds to Figure 7 A reader / writer is installed every 80 meters along the 300-meter-long scraper conveyor, at the head, tail, and middle sections. The reader / writer antennas are circularly polarized to ensure stable reading of tags in any orientation. The reader / writer incorporates the dynamic frame-slot Aloha anti-collision algorithm.

[0154] When the chain runs at 1.5 m / s, each reader can simultaneously identify approximately 15-20 tags within its area. Based on the collision rate of the previous round, the reader dynamically adjusts the frame length parameter Q (which adaptively adjusts between 4 and 8) for the next round, ensuring optimal system throughput. Testing showed that even with dense tag traffic, the single-tag read success rate remains above 99.95%, effectively preventing missed reads due to collisions.

[0155] Example 6: Performance Verification of Fiber Composite Antenna

[0156] In this embodiment, the antenna radiator 102 is made of a fiber composite material (T700 / epoxy) consistent with the chain link body. Utilizing the anisotropic conductivity of the fiber composite material, and by designing the fiber layup direction (longitudinal arrangement), the antenna radiator 102 exhibits low transverse conductivity in the sensitive fracture region. While maintaining high vertical conductivity in other regions After electromagnetic simulation optimization, the antenna resonant frequency is 915MHz, the radiation efficiency is 58%, and the readout distance can reach 3.2 meters. Mechanical tests show that the antenna is firmly integrated with the chain link body, and its fatigue life is consistent with that of the chain link.

[0157] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. An in-line break detection label, characterized by: include The dielectric substrate (101) adopts a flexible structure; The antenna radiator (102) is attached to the surface of the dielectric substrate (101) and is in a closed-loop shape. At least two mechanically weak points are provided on the antenna radiator (102). The radio frequency chip (103) is electrically connected to the antenna radiator (102); The encapsulation layer (104) covers the dielectric substrate (101), the antenna radiator (102), and the radio frequency chip (103).

2. An in-line breakage detection label according to claim 1, characterised in that: The mechanically weak parts are distributed along the dangerous section of the chain link. The fracture strength of the mechanically weak parts is lower than that of the chain link body, and the location of the mechanically weak parts corresponds to the expected fracture danger area of ​​the chain link.

3. An in-line breakage detection label according to claim 2, characterised in that: The antenna radiator (102) is made of fiber composite material, and the fibers are arranged along the length of the mechanically weak part.

4. A mine chain break monitoring system characterized by: include Sensing layer: Multiple embedded fracture detection tags as described in any one of claims 1-3 are embedded one-to-one inside each link of the scraper conveyor chain; Data Acquisition Layer: Multiple fixed readers are distributed and installed at the head, tail, and middle trough of the scraper conveyor to periodically read the tag ID and collect the tag's signal characteristic parameters; Transport layer: Mining gateway, which communicates with each reader / writer; Platform layer: Monitoring center, which communicates with the gateway and is used to receive and process data. The monitoring center also collects the operating parameters of the scraper conveyor synchronously.

5. A mine chain break monitoring system according to claim 4, characterised in that: Each reader includes an antenna and a reading / writing module. The antenna is a circularly polarized antenna. The reader has a built-in anti-collision algorithm that can dynamically adjust the reading strategy based on the number of tags in the recognition area.

6. A method for detecting and warning of a breakage of a mine chain based on the mine chain breakage monitoring system according to any one of claims 4-5, characterized in that: Includes the following steps: S1. Establish a chain-tag mapping table to record the reference signal characteristic parameters of each tag; S2. Real-time monitoring: The reader continuously reads the tag ID and collects the tag's signal characteristic parameters, while simultaneously collecting the scraper conveyor's operating parameters. S3. Fracture event determination: Based on multi-source data fusion judgment of tag existence status, neighboring tag status and equipment operating parameters; S4. Progressive damage warning: a damage index is constructed based on the changes in the characteristic parameters of the tag signal. When the damage index exceeds a preset threshold, a warning is issued. S5. Location and Alarm.

7. The mine chain breakage detection and warning method according to claim 6, characterized in that: The conditions for determining the fracture event in S3 include: The tag was not read in several consecutive read cycles; Adjacent tags located before and after the broken chain link were read normally within the same time window; The equipment operating parameters exhibit characteristic changes associated with the chain break event. These characteristic changes are used to extract singularity features of the current signal through wavelet transform, or to determine whether the current mutation rate exceeds a preset range through threshold comparison.

8. The mine chain breakage detection and warning method according to claim 7, characterized in that: The damage index constructed in S4 is obtained by weighting multiple signal feature parameters based on their offsets, and the weighting coefficients can be adaptively adjusted according to the chain link type and operating conditions.

9. The mine chain break detection and warning method of claim 8, wherein: The signal characteristic parameters include at least one or more of the following: readout power threshold, resonant frequency, backscattered signal strength, and signal phase.

10. A mining chain characterized by: The chain links are embedded with the embedded fracture detection tag as described in any one of claims 1-3.

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