Scraper conveyor wear and operating condition embedded wireless monitoring device and method

Abstract

The application discloses a scraper conveyor wear and running state embedded wireless monitoring device and method, and belongs to the technical field of scraper conveyor state monitoring. The device is embedded in the scraper body and comprises a scraper thickness measurement unit, a scraper vibration state measurement unit, a signal acquisition and processing module, a thickness inversion and state identification module and a wireless communication module. The scraper thickness measurement unit utilizes the thermal response signal generated by frictional heat during the operation of the scraper to output a thermoelectric signal related to the residual thickness of the scraper; the scraper vibration state measurement unit collects the running vibration signal of the scraper through a cantilever beam type piezoelectric vibrator; and the thickness inversion and state identification module obtains the residual thickness, wear amount and running vibration state of the scraper based on the thermoelectric response characteristics and vibration state characteristics and a preset mapping relationship or an inversion model. The application can realize online quantitative measurement of the wear thickness of the scraper and running state monitoring, and improve the measurement accuracy, stability and engineering adaptability.

Description

Technical Field

[0001] This invention relates to the field of scraper conveyor condition detection technology, specifically to an embedded wireless monitoring device and method for scraper conveyor wear and operating status. Background Technology

[0002] Scraper conveyors are key transportation equipment in underground coal mine longwall faces and tunneling systems, primarily used for the continuous transport of coal, gangue, and other bulk materials. As the direct load-bearing and pushing component in the scraper conveyor's chain drive system, the scraper blades are prone to wear under long-term heavy loads, impacts, and friction, resulting in continuous contact with the central trough, chain, and conveyed material. This wear can lead to problems such as localized thinning, uneven wear, and impact damage. As wear intensifies, the remaining thickness of the scraper blade decreases, reducing its load-bearing capacity and operational stability. In severe cases, this can lead to scraper blade breakage, chain jamming, chain skipping, or even machine shutdown. Therefore, online monitoring of scraper blade wear thickness and operating status is of great significance.

[0003] Existing methods for scraper condition monitoring mainly include manual shutdown inspection, periodic disassembly and inspection, and external sensor detection. Manual inspection and disassembly and inspection methods suffer from high labor intensity, low efficiency, and poor real-time performance, making it difficult to meet the online monitoring needs of continuously operating equipment. Although external sensors can collect certain status information, they are susceptible to interference from coal dust, water mist, material collisions, and structural vibrations in the high dust, high humidity, strong impact, and strong vibration environment of underground coal mines. They also suffer from difficulties in installation and maintenance, insufficient reliability, and poor long-term stability.

[0004] For measuring scraper wear thickness, existing technologies typically employ mechanical measurement, ultrasonic testing, eddy current testing, or indirect temperature assessment. Mechanical measurement and offline testing cannot achieve continuous online monitoring. Ultrasonic and eddy current testing have high requirements for installation location, coupling state, and on-site environment, limiting their application in the context of frequent impacts, friction, and wear on the moving parts of scraper conveyors. Utilizing thermal response information to assess wear status is feasible to some extent, as scraper wear alters local heat conduction paths, thermal resistance distribution, and temperature rise characteristics. However, relying solely on thermal signals for thickness determination is easily affected by factors such as operating speed, load changes, friction conditions, and environmental heat dissipation conditions, leading to insufficient accuracy and stability in thickness inversion.

[0005] For monitoring operational vibration, piezoelectric sensing technology offers advantages such as simple structure, high sensitivity, ease of miniaturization, and suitability for embedded installation, enabling it to sense vibration, impact, and frequency changes generated during scraper operation. However, existing piezoelectric detection solutions often focus on single vibration monitoring or fault identification, making it difficult to establish a stable quantitative correlation with scraper wear thickness. Furthermore, scraper vibration is characterized by wide frequency range, multiple impacts, and rapid changes in operating conditions. If the frequency response of the measurement unit and the installation boundary conditions do not match the target vibration frequency band, problems such as insufficient response and unstable feature extraction can easily occur.

[0006] In addition, most existing thermoelectric and piezoelectric related devices are mainly aimed at environmental energy harvesting, self-powered or auxiliary power supply, focusing on improving output power, broadening the energy harvesting frequency band or optimizing heat dissipation performance. A collaborative measurement scheme that is suitable for the narrow space inside the scraper and can simultaneously realize quantitative inversion of wear thickness and identification of operating vibration status has not yet been formed.

[0007] Therefore, there is an urgent need to provide a collaborative measurement device and method suitable for embedded installation inside the scraper of a scraper conveyor. This device and method can use thermoelectric signals to invert the scraper wear thickness, use piezoelectric signals to identify the scraper's operating vibration state, and use vibration state characteristics to perform working condition compensation for the thickness inversion, thereby improving the linearity, quantification, stability, and engineering adaptability of scraper wear monitoring. Summary of the Invention

[0008] The purpose of this invention is to provide an embedded wireless monitoring device and method for scraper conveyor wear and operating status, to solve the problems of difficulty in online quantitative measurement of scraper wear thickness, susceptibility of single thermal response signals to fluctuations in operating conditions, and difficulty in stably obtaining operating vibration status. By inverting the remaining scraper thickness using thermoelectric signals and extracting operating vibration characteristics as operating condition compensation using piezoelectric signals, the accuracy, stability, and engineering adaptability of scraper wear thickness measurement are improved.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is as follows: Firstly, the present invention proposes an embedded wireless monitoring device for wear and operating status of a scraper conveyor, comprising: a scraper thickness measuring unit, including a heat transfer component and a thermoelectric conversion element, wherein the thermoelectric conversion element includes a hot end and a cold end; the heat transfer component is thermally connected to the wear area of ​​the scraper body; the hot end of the thermoelectric conversion element is thermally connected to the heat transfer component; further comprising a cold end thermal management structure, wherein the cold end thermal management structure is connected to the cold end of the thermoelectric conversion element, and is used to regulate heat dissipation at the cold end to maintain a stable cold end temperature; the thermoelectric conversion element outputs a thermoelectric signal when a temperature difference is formed between its hot end and cold end, the thermoelectric signal including thermoelectric voltage and thermoelectric current; an equivalent hot-cold end temperature difference can be calculated based on the thermoelectric signal, wherein the thermoelectric signal includes one or more of thermoelectric voltage, thermoelectric current, or the equivalent hot-cold end temperature difference calculated therefrom.

[0010] The scraper vibration state measurement unit is disposed along the thickness direction of the scraper body on the side of the scraper thickness measurement unit away from the wear area. The scraper vibration state measurement unit includes at least one cantilever beam piezoelectric vibrator. The cantilever beam piezoelectric vibrator is used to generate piezoelectric signals under the vibration or impact of the scraper operation. The piezoelectric signals are used to characterize the vibration amplitude, frequency components or impact characteristics of the scraper during operation.

[0011] The signal acquisition and processing module is connected to the scraper thickness measurement unit and the scraper vibration state measurement unit, respectively.

[0012] The thickness inversion and state recognition module is connected to the signal acquisition and processing module. The thickness inversion and state recognition module stores a preset mapping relationship or inversion model, which is used to calculate the remaining thickness and operating state of the scraper based on the features extracted from the acquired thermoelectric and piezoelectric signals.

[0013] The wireless communication module, connected to the signal acquisition and processing module and the thickness inversion and status recognition module, is used to wirelessly transmit the remaining thickness of the scraper, wear amount, operating vibration status, early warning information, and sensor anomaly information to an external receiving terminal or downhole monitoring gateway.

[0014] The power supply unit provides operating power to the entire monitoring device.

[0015] As a further improvement of the present invention, the scraper thickness measurement unit, scraper vibration state measurement unit, signal acquisition and processing module and thickness inversion and state recognition module are installed in a flow guide box, and an installation cavity is provided inside the scraper, and the flow guide box is embedded in the installation cavity.

[0016] As a further improvement of the present invention, the cold-end thermal management structure includes heat dissipation fins, which are located above the cantilever beam piezoelectric vibrator.

[0017] As a further improvement of the present invention, the cold end thermal management structure further includes a flow guiding cavity; the flow guiding cavity is the internal cavity of the flow guiding box, and the flow guiding box is provided with an arc-shaped cover to form an arc-shaped flow guiding cavity inside the box, which is used to guide the air generated by the vibration of the free end of the cantilever beam piezoelectric vibrator to the cold end region to regulate the cold end temperature.

[0018] As a further improvement of the present invention, a permanent magnet is provided at the free end of the cantilever beam piezoelectric vibrator.

[0019] As a further improvement of the present invention, the scraper vibration state measurement unit further includes a tuning component, which includes a piezoelectric vibrator spacing adjustment mechanism. The piezoelectric vibrator spacing adjustment mechanism includes a mounting plate, a slider, a spring, a first drive motor, and a first lead screw. A slide rail is provided on the mounting plate, and multiple sliders are embedded in the slide rail and can slide back and forth along the slide rail. One end of the cantilever beam piezoelectric vibrator is fixedly connected to the slider, and the spring is located between two adjacent sliders and fixedly connected to the slider. The spacing between the sliders is equal. The bottoms of the two first drive motors are respectively fixed to the two ends of the mounting plate, and the first drive motors are shaft-connected to the first lead screw. A through threaded hole is provided in the middle of the outermost slider, and the first lead screw is threadedly connected to the threaded hole.

[0020] As a further improvement of the present invention, the tuning assembly further includes a piezoelectric vibrator amplitude adjustment mechanism, which includes a second drive motor, a second lead screw, and an adjustment plate. The adjustment plate is provided with a strip-shaped opening through which all cantilever beam piezoelectric vibrators pass. The adjustment plate is fixedly connected to the second lead screw, and under the drive of the second drive motor, the clamping position of the adjustment plate on the cantilever beam piezoelectric vibrator is controlled to adjust its vibration amplitude.

[0021] As a further improvement of the present invention, the thickness inversion and state recognition module has a pre-stored database or inversion model of the mapping relationship between thermoelectric response characteristics, vibration state characteristics and scraper remaining thickness, and obtains the current scraper remaining thickness, wear amount and operating vibration state through table lookup, interpolation, regression calculation, data fusion or machine learning recognition methods.

[0022] Secondly, the present invention also proposes an embedded wireless monitoring method for wear and operating status of scraper conveyors. Based on the embedded wireless monitoring device for wear and operating status of scraper conveyors, the method includes the following steps: Step S1: Before the scraper runs, record the initial thickness of the scraper, the minimum allowable remaining thickness, the initial output parameters of the thermoelectric conversion element, and the initial spacing and initial clamping position of the cantilever beam piezoelectric vibrator.

[0023] Step S2: During the scraper's operation, the wear area of ​​the scraper generates heat through friction with the central groove, chain, and conveyed material. This heat is transferred to the hot end of the thermoelectric conversion element via the scraper body and heat transfer components. Simultaneously, the cold end of the thermoelectric conversion element is regulated by the cold end thermal management structure to create a temperature difference between the hot and cold ends of the thermoelectric conversion element, which is related to the remaining thickness of the scraper, and a thermoelectric signal is output. The piezoelectric signal generated by the cantilever beam piezoelectric vibrator under the vibration of the scraper is collected synchronously, and the thermoelectric and piezoelectric signals are time-stamped.

[0024] Step S3: Within the preset sampling window, calculate one or more parameters from the current vibration amplitude, peak-to-peak value, root mean square value, main frequency, frequency band energy, signal-to-noise ratio, and output saturation state based on the acquired piezoelectric signal; when the piezoelectric signal is lower than the preset effective threshold, exceeds the range of the acquisition circuit, the main frequency deviates from the target frequency band, or the signal-to-noise ratio is lower than the preset threshold, generate a tuning command.

[0025] Step S4: According to the tuning command, the response characteristics of the scraper vibration state measurement unit are adjusted using the tuning component; wherein, the spacing between adjacent cantilever beam piezoelectric vibrators is changed by the piezoelectric vibrator spacing adjustment mechanism to adjust the coupling state and response frequency band of the piezoelectric vibrator array; the effective vibration length or clamping position of the cantilever beam piezoelectric vibrator is changed by the piezoelectric vibrator amplitude adjustment mechanism to adjust its vibration amplitude, natural frequency and output sensitivity; and the tuning component is locked after the adjustment is completed.

[0026] Step S5: The thermoelectric signal and piezoelectric signal are amplified, filtered, converted from analog to digital and outlier removed by the signal acquisition and processing module; one or more thermal response features are extracted from the thermoelectric signal, including steady-state thermoelectric voltage, transient voltage change rate, equivalent hot and cold junction temperature difference and temperature rise response time; one or more vibration state features are extracted from the piezoelectric signal, including vibration amplitude, peak-to-peak value, root mean square value, dominant frequency, frequency band energy, impact factor and kurtosis.

[0027] Step S6: Identify the current operating vibration state of the scraper based on the vibration state characteristics, and input the vibration state characteristics as the working condition compensation quantity into the thickness inversion and state identification module; The thickness inversion and state identification module calculates the current remaining thickness of the scraper by calling the preset thermoelectric response characteristics-vibration state characteristics-scraper remaining thickness mapping relationship or inversion model based on the thermal response characteristics and vibration state characteristics.

[0028] Step S7: Calculate the scraper wear based on the initial scraper thickness and the current remaining scraper thickness, and output the scraper wear status, operating vibration status, and early warning information based on one or more of the following results: remaining scraper thickness, wear amount, wear change trend, and operating vibration status.

[0029] As a further improvement of the present invention, in step S6, the establishment of the mapping relationship or inversion model of thermoelectric response characteristics-vibration state characteristics-remaining thickness of scraper includes the following steps: Step S61, according to the scraper model, material, initial thickness and allowable wear limit, the remaining thickness of scraper is divided into multiple thickness levels to form a scraper remaining thickness sample set.

[0030] Step S62: Establish multiple operating condition samples based on one or more parameters of the scraper conveyor, such as operating speed, load size, material state, impact intensity, and environmental heat dissipation conditions.

[0031] Step S63: Under different scraper remaining thickness levels and different operating conditions, collect the thermoelectric signals output by the thermoelectric conversion element and the piezoelectric signals output by the cantilever beam piezoelectric vibrator, and extract the corresponding thermal response characteristics and vibration state characteristics.

[0032] Step S64: Establish a correspondence between the remaining thickness of the scraper, thermal response characteristics and vibration state characteristics to form a mapping relationship database, or establish a regression model, interpolation model, data fusion model or machine learning inversion model based on the correspondence.

[0033] Step S65: During the actual operation of the scraper, the real-time thermal response characteristics and vibration state characteristics are input into the mapping database or inversion model. The vibration state characteristics are used to compensate for the deviation of the thermoelectric signal caused by the change of operating conditions, and the corrected remaining thickness of the scraper is obtained.

[0034] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention utilizes thermoelectric response characteristics to invert the remaining thickness of the scraper and introduces piezoelectric vibration state characteristics as working condition compensation into the thickness inversion process, which can reduce the influence of operating speed, load changes, impact disturbances and friction state changes on the thickness measurement results, and improve the accuracy and stability of wear thickness inversion.

[0035] 2. By setting up a piezoelectric vibrator spacing adjustment mechanism and a piezoelectric vibrator amplitude adjustment mechanism, the present invention can adjust the response characteristics of the scraper vibration state measurement unit according to the scraper operating conditions, so as to maintain high sensitivity in the target vibration frequency band and improve the stability of vibration feature extraction.

[0036] 3. The present invention adopts an embedded arrangement, placing the measuring unit inside the scraper body and protecting it through encapsulation, sealing and buffer support structure, which can reduce the influence of coal dust, water mist, material impact and external environment on the measurement results, and is suitable for underground strong impact, strong vibration and high dust conditions.

[0037] 4. This invention can output the remaining thickness of the scraper, wear amount, operating vibration status and early warning information, which is conducive to realizing online monitoring and fault early warning of the scraper wear status of the scraper conveyor, and improving the reliability of equipment operation and the timeliness of maintenance. Attached Figure Description

[0038] Figure 1 This is a combined diagram of the scraper thickness measurement unit and the scraper vibration measurement unit of the present invention.

[0039] Figure 2 This is a diagram showing the state of the scraper thickness measurement unit and the scraper vibration measurement unit installed inside the flow guide box.

[0040] Figure 3 This is a diagram of the airflow guide box.

[0041] Figure 4 This is a schematic diagram of the piezoelectric vibrator spacing adjustment mechanism.

[0042] Figure 5 This is a schematic diagram of the flow guide box installed on the scraper.

[0043] Explanation of markings in the diagram: 1. Flow guide box; 101. Box body; 102. Cover body; 2. Thermoelectric generator; 21. Hot end; 22. Cold end; 3. Heat dissipation fins; 4. Cantilever beam piezoelectric vibrator; 5. Permanent magnet; 6. Mounting plate; 7. Slider; 8. Spring; 9. First drive motor; 10. First lead screw; 11. Second drive motor; 12. Second lead screw; 13. Adjusting plate; 131. Strip-shaped opening; 14. Scraper; 141. Scraper middle plate; 142. Scraper wing plate. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention are within the scope of protection of the present invention.

[0045] like Figures 1 to 5 As shown, the embedded wireless monitoring device for wear and operating status of scraper conveyors of the present invention includes a scraper thickness measurement unit, a scraper vibration status measurement unit, a signal acquisition and processing module, a thickness inversion and status identification module, and a wireless communication module.

[0046] The scraper thickness measurement unit is used to collect the thermal response signal generated by the contact friction between the scraper and the central trough, chain, and / or conveyed material during scraper operation. The scraper thickness measurement unit includes a heat transfer component and a thermoelectric conversion element. The thermoelectric conversion element is a thermoelectric generator 2, including a hot end 21 and a cold end 22. The heat transfer component is thermally connected to the wear area of ​​the scraper body, and the hot end 21 is thermally connected to the heat transfer component. Specifically, the heat transfer component is one or more of a heat-conducting block, heat-conducting column, heat-conducting sheet, or heat-conducting adhesive layer. One end of the heat transfer component is attached or embedded in the inner wall surface of the scraper body near the wear area, and the other end is attached to the hot end of the thermoelectric conversion element. A thermally conductive interface material is filled between the heat transfer component and the scraper body, or it is tightened by fasteners to reduce contact thermal resistance. To improve thermal response repeatability, the heat transfer component is preferably made of copper, aluminum, thermally conductive ceramics, thermally conductive alloys, or high thermal conductivity composite materials. Thermal grease, thermal pads, or thermal adhesive layers can be placed between the heat transfer components and the scraper body, and stable contact can be maintained through clamping parts, screws, clips, or potting structures, thereby ensuring that the heat in the wear area of ​​the scraper wear zone is preferentially transferred to the hot end of the thermoelectric conversion element through the heat transfer components.

[0047] The scraper vibration state measurement unit is used to collect vibration response signals during scraper operation. Located above the scraper thickness measurement unit, the scraper vibration state measurement unit includes one or more cantilever beam piezoelectric vibrators 4.

[0048] The signal acquisition and processing module is connected to the scraper thickness measurement unit and the scraper vibration state measurement unit, respectively, and is used to perform front-end conditioning, sampling, and feature extraction on the two different types of output signals. The thickness inversion and state recognition module is connected to the signal acquisition and processing module and is used to obtain the remaining thickness, wear amount, and operating vibration state of the scraper based on the thermoelectric signal and the vibration state characteristics extracted from the piezoelectric signal, according to a preset mapping relationship or inversion model.

[0049] The wireless communication module is connected to the signal acquisition and processing module and the thickness inversion and status recognition module. It is used to wirelessly transmit the remaining scraper thickness, wear amount, operating vibration status, early warning information, and sensor anomaly information to an external receiving terminal or downhole monitoring gateway. In this embodiment, the wireless communication module can employ one or more of ZigBee, LoRa, WiFi, Bluetooth, UWB, NB-IoT, or intrinsically safe mining wireless communication units. The wireless communication module is housed within the flow guide box or sealed to it. Its antenna communicates with the external monitoring terminal through a non-metallic wave-transparent window, an insulating encapsulation area, or a non-load-bearing area of ​​the scraper to reduce the shielding effect of the metal scraper on the wireless signal.

[0050] The thickness inversion and state recognition module is connected to the signal acquisition and processing module. It is used to comprehensively analyze the remaining thickness, wear amount and operating vibration state of the scraper based on the thermoelectric signal output by the thermoelectric thickness measurement unit and the piezoelectric signal output by the scraper vibration state measurement unit. The thickness inversion and state recognition module and the signal acquisition and processing module are encapsulated in a controller. The thickness inversion and state recognition module has a pre-stored database or inversion model of the mapping relationship between thermoelectric response characteristics, vibration state characteristics and scraper remaining thickness. It obtains the current remaining thickness, wear amount and operating vibration state of the scraper through table lookup, interpolation, regression calculation, data fusion or machine learning recognition methods.

[0051] In this embodiment, the thermoelectric signal can be one or more of the steady-state voltage, transient voltage change rate, and equivalent temperature difference between the hot and cold ends of the thermoelectric conversion element. As the wear of the scraper increases, the remaining thickness of the worn area decreases, and the local heat conduction path, thermal resistance distribution, and heat diffusion characteristics change, thereby altering the thermal response characteristics of the thermoelectric conversion element. Therefore, the current remaining thickness and wear amount of the scraper can be calculated by pre-establishing a mapping relationship between "thermoelectric response characteristics - scraper remaining thickness" or "thermoelectric response characteristics - vibration state characteristics - scraper remaining thickness".

[0052] The scraper thickness measurement unit, scraper vibration state measurement unit, signal acquisition and processing module, and thickness inversion and state recognition module are installed in a flow guide box 1. An installation cavity is provided inside the scraper 14, and the flow guide box 1 is embedded in and fixed within the installation cavity. Specifically, the scraper 14 includes a scraper middle plate 141 and a scraper blade 142, and the flow guide box 1 is installed on the scraper blade 142. The flow guide box 1 includes a box body 101 and a cover 102, wherein the cover 102 has a convex arc-shaped structure.

[0053] The mounting cavity is preferably located on the back coal surface of the scraper blade 142, without contacting the coal. The mounting cavity can be equipped with heat dissipation holes with a dustproof, waterproof, and breathable membrane or a labyrinthine ventilation structure to achieve ventilation within the cavity while ensuring sealing and protection performance. The scraper thickness measurement unit also includes a cold-end thermal management structure for cooling and regulating the cold end 22. The cold-end thermal management structure includes heat dissipation fins 3, located above the cantilever beam piezoelectric vibrator 4. The cold-end thermal management structure also includes a flow guiding cavity, which is formed by an arc-shaped cavity created by the arc-shaped cover of the flow guiding box 1. This cavity guides the airflow inside the scraper or the local air disturbance generated during the vibration of the piezoelectric vibrator, forming a directional airflow acting on the cold end region of the thermoelectric conversion element. The heat dissipation fins 3 increase the cold-end heat exchange area and improve the stability of the cold-end boundary conditions, thereby improving the repeatability and accuracy of the thermoelectric signal when used for wear thickness inversion.

[0054] Preferably, the scraper vibration state measurement unit includes three cantilever piezoelectric transducers 4. Each cantilever piezoelectric transducer 4 includes an elastic base layer and a piezoelectric material layer disposed on the surface of the elastic base layer, with a permanent magnet 5 disposed at the free end. The cantilever piezoelectric transducers 4 are arranged in an array, and can form a wideband, high-sensitivity response structure through the magnetic coupling relationship between the permanent magnets 5 at the free ends and the spatial distribution of the array. By designing the transducer spacing, end mass, and magnetic pole direction, the natural frequency of each piezoelectric transducer covers the target frequency band, thereby maintaining a high response even under non-single resonance conditions, so as to achieve stable measurement of the scraper's operating vibration state.

[0055] When the permanent magnets 5 at the free ends of each cantilever piezoelectric vibrator 4 are arranged close to each other, the magnetic force between them exhibits a nonlinear relationship with the relative displacement and spacing. This nonlinear magnetic force, together with the elastic restoring force of the cantilever beam itself, enables the piezoelectric vibrator array to form a nonlinear dynamic response characteristic. When the external excitation is small, the cantilever piezoelectric vibrator 4 mainly vibrates near the local equilibrium position; when the excitation increases or the frequency changes, the response amplitude and frequency components of the cantilever piezoelectric vibrator 4 change significantly, which is beneficial for extracting characteristic parameters such as vibration amplitude, dominant frequency, impact degree, and frequency band energy during the scraper operation. By adjusting the spacing, magnetic pole direction, magnetic properties, and end mass of the permanent magnets 5, the sensitivity distribution and frequency response range of the piezoelectric vibrator array can be further changed, thereby improving the ability to identify the vibration state of the scraper under complex working conditions.

[0056] In this embodiment, the scraper vibration state measurement unit further includes a tuning component, which includes a piezoelectric vibrator spacing adjustment mechanism and a piezoelectric vibrator amplitude adjustment mechanism. The piezoelectric vibrator spacing adjustment mechanism includes a mounting plate 6, sliders 7, springs 8, a first drive motor 9, and a first lead screw 10. A slide rail is provided on the mounting plate 6, and multiple sliders 7 are embedded in the slide rail and can slide back and forth along the slide rail. One end of the cantilever beam piezoelectric vibrator 4 is fixedly connected to the slider 7. The spring 8 is located between two adjacent sliders 7 and is fixedly connected to the slider 7. The spacing between the sliders 7 is equal. The bottoms of the two first drive motors 9 are respectively fixed to both ends of the mounting plate, and each first drive motor is shaft-connected to the first lead screw 10. A through threaded hole is provided in the middle of the outermost slider 7, and the first lead screw 9 is threadedly connected to the threaded hole.

[0057] The piezoelectric vibrator amplitude adjustment mechanism includes a second drive motor 11, a second lead screw 12, and an adjustment plate 13. The adjustment plate 13 has a slot 131 through which all cantilever piezoelectric vibrators 4 pass. The output shaft of the second drive motor 11 is connected to the second lead screw 12. The adjustment plate 13 has a threaded hole or nut seat that mates with the second lead screw 12. When the second lead screw 12 rotates, it drives the adjustment plate 13 to move along the length of the cantilever piezoelectric vibrator 4, thereby changing the clamping position of the adjustment plate 13 on the cantilever piezoelectric vibrator 4 and thus adjusting its vibration amplitude.

[0058] The present invention also proposes an embedded wireless monitoring method for wear and operating status of scraper conveyors, including the following steps: Step S1: Before the scraper runs, record the initial thickness of the scraper, the minimum allowable remaining thickness, the initial output parameters of the thermoelectric conversion element, and the initial spacing and initial clamping position of the cantilever beam piezoelectric vibrator 4.

[0059] Step S2: During the scraper's operation, the scraper's wear area generates heat through friction with the central trough, chain, and conveyed material. This heat is transferred to the hot end of the thermoelectric conversion element via the scraper body and heat transfer components. Simultaneously, the cold end of the thermoelectric conversion element is regulated by the cold end thermal management structure to create a temperature difference between the hot and cold ends of the thermoelectric conversion element, which is related to the remaining thickness of the scraper, and a thermoelectric signal is output. The piezoelectric signal generated by the cantilever beam piezoelectric vibrator under the vibration of the scraper is collected synchronously, and the thermoelectric and piezoelectric signals are time-stamped.

[0060] The air disturbance generated by the vibration of the cantilever beam piezoelectric vibrator 4 is directed to the cold end region of the thermoelectric conversion element by the arc-shaped flow guide cavity in the flow guide box. The heat exchange area is increased by the heat dissipation fins 3 set in the cold end region to reduce the temperature fluctuation of the cold end of the thermoelectric conversion element, so that the thermoelectric signal output by the thermoelectric conversion element mainly reflects the change of heat conduction state in the wear area of ​​the scraper.

[0061] Step S3: Within the preset sampling window, calculate one or more parameters from the current vibration amplitude, peak-to-peak value, root mean square value, main frequency, frequency band energy, signal-to-noise ratio, and output saturation state based on the acquired piezoelectric signal; when the piezoelectric signal is lower than the preset effective threshold, exceeds the range of the acquisition circuit, the main frequency deviates from the target frequency band, or the signal-to-noise ratio is lower than the preset threshold, generate a tuning command.

[0062] Step S4: According to the tuning command, adjust the response characteristics of the scraper vibration state measurement unit using the tuning component; wherein, the spacing between adjacent cantilever beam piezoelectric vibrators is changed by the piezoelectric vibrator spacing adjustment mechanism to adjust the coupling state and response frequency band of the piezoelectric vibrator array; and / or the effective vibration length or limit position of the cantilever beam piezoelectric vibrator is changed by the piezoelectric vibrator amplitude adjustment mechanism to adjust its vibration amplitude, natural frequency and output sensitivity; after the adjustment is completed, lock the tuning component.

[0063] It should be noted that the tuning component can operate during the low-speed operation phase, stable operation phase, preset adjustment window, or shutdown maintenance state of the scraper conveyor. When the scraper is subjected to strong impact, severe load fluctuations, or during the effective window for piezoelectric signal acquisition, the tuning mechanism remains locked and does not perform mechanical adjustment actions. This avoids mechanical disturbances or electromagnetic interference to piezoelectric signal acquisition caused by the movement of the first drive motor 9, the second drive motor 11, the first lead screw 10, the second lead screw 12, the slider 7, and the adjusting plate 13, and improves the reliability of the tuning mechanism under strong impact conditions.

[0064] Based on one or more parameters of the current piezoelectric signal, such as vibration amplitude, dominant frequency, bandwidth energy, signal-to-noise ratio, and output saturation state, the target spacing is determined in the preset vibration state characteristics-optimal spacing correspondence of piezoelectric vibrators. The first drive motor 9 is controlled to move, causing the spring 8 to drive multiple sliders 7 to move synchronously along the slide rails on the mounting plate, thereby changing the spacing between multiple cantilever beam piezoelectric vibrators 4. When the actual spacing between adjacent cantilever beam piezoelectric vibrators 4 reaches the target spacing or enters the allowable error range, the first drive motor 9 is stopped and the position of the sliders 7 is locked.

[0065] Based on one or more parameters among the current piezoelectric signal's dominant frequency, vibration amplitude, and output saturation state, the target position of the adjustment plate 13 along the length of the cantilever piezoelectric vibrator 4 is determined; the second drive motor 11 is controlled to move the adjustment plate 13, causing the positions of the multiple cantilever piezoelectric vibrators 4 passing through the strip opening 131 on the adjustment plate to change, thereby altering the effective vibration length and output amplitude of the cantilever piezoelectric vibrator 4; when the adjustment plate 13 moves to the target position or enters the allowable error range, the second drive motor 11 is stopped and the position of the adjustment plate 13 is maintained.

[0066] Step S5: The thermoelectric signal and piezoelectric signal are amplified, filtered, converted from analog to digital and outlier removed by the signal acquisition and processing module respectively; one or more thermal response features are extracted from the thermoelectric signal, including steady-state thermoelectric voltage, transient voltage change rate, equivalent hot and cold junction temperature difference and temperature rise response time; one or more vibration state features are extracted from the piezoelectric signal, including vibration amplitude, peak-to-peak value, root mean square value, dominant frequency, frequency band energy, impact factor and kurtosis.

[0067] Step S6: Identify the current operating vibration state of the scraper based on the vibration state characteristics, and input the vibration state characteristics as the working condition compensation quantity into the thickness inversion and state identification module; The thickness inversion and state identification module calculates the current remaining thickness of the scraper by calling the preset thermoelectric response characteristics-vibration state characteristics-scraper remaining thickness mapping relationship or inversion model based on the thermal response characteristics and vibration state characteristics.

[0068] Specifically, the establishment of the mapping relationship or inversion model between thermoelectric response characteristics, vibration state characteristics and scraper remaining thickness includes the following steps: Step S61, based on the scraper model, material, initial thickness and allowable wear limit, the scraper remaining thickness is divided into multiple thickness levels to form a scraper remaining thickness sample set.

[0069] Step S62: Establish multiple operating condition samples based on one or more parameters of the scraper conveyor, such as operating speed, load size, material state, impact intensity, and environmental heat dissipation conditions.

[0070] Step S63: Under different scraper remaining thickness levels and different operating conditions, collect the thermoelectric signals output by the thermoelectric conversion element and the piezoelectric signals output by the cantilever beam piezoelectric vibrator, and extract the corresponding thermal response characteristics and vibration state characteristics.

[0071] Step S64: Establish a correspondence between the remaining thickness of the scraper, thermal response characteristics and vibration state characteristics to form a mapping relationship database, or establish a regression model, interpolation model, data fusion model or machine learning inversion model based on the correspondence.

[0072] Step S65: During the actual operation of the scraper, the real-time thermal response characteristics and vibration state characteristics are input into the mapping database or inversion model. The vibration state characteristics are used to compensate for the deviation of the thermoelectric signal caused by changes in operating conditions, and the corrected remaining thickness of the scraper is obtained. One or more vibration state characteristics, including vibration amplitude, peak-to-peak value, root mean square value, dominant frequency, frequency band energy, impact factor, and kurtosis, are compared with preset state thresholds or state identification models to determine whether the scraper is in normal operation, impact enhancement, abnormal vibration, risk of uneven wear, or fault warning state. The operating vibration state is used as the operating condition compensation information for thickness inversion.

[0073] Step S7: Calculate the scraper wear based on the initial scraper thickness and the current remaining scraper thickness, and output the scraper wear status, operating vibration status, and early warning information based on one or more of the following results: remaining scraper thickness, wear amount, wear change trend, and operating vibration status.

[0074] When the remaining thickness of the scraper is less than the preset thickness threshold, the wear amount is greater than the preset wear threshold, the wear growth rate per unit time is greater than the preset change rate threshold, or the operating vibration state is identified as abnormal, a wear warning, a vibration abnormality warning, or a maintenance prompt will be output; when the thermoelectric signal or piezoelectric signal exceeds the effective acquisition range, a sensor abnormality prompt or a tuning abnormality prompt will be output.

[0075] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited thereto. Various changes that can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention are all within the protection scope of the claims of the present invention.

Claims

1. An embedded wireless monitoring device for wear and operating status of a scraper conveyor, characterized in that, include: The scraper thickness measuring unit includes a heat transfer component and a thermoelectric conversion element. The thermoelectric conversion element includes a hot end and a cold end. The heat transfer component is thermally connected to the wear area of ​​the scraper body. The hot end of the thermoelectric conversion element is thermally connected to the heat transfer component. The unit also includes a cold end thermal management structure, which is connected to the cold end of the thermoelectric conversion element and is used to regulate the heat dissipation of the cold end to maintain a stable cold end temperature. The thermoelectric conversion element is used to output a thermoelectric signal when a temperature difference is formed between its hot and cold ends. The thermoelectric signal includes thermoelectric voltage and thermoelectric current. The equivalent hot and cold end temperature difference can be calculated based on the thermoelectric signal. A scraper vibration state measurement unit is disposed along the thickness direction of the scraper body on the side of the scraper thickness measurement unit away from the wear area. The scraper vibration state measurement unit includes at least one cantilever beam piezoelectric vibrator. The cantilever beam piezoelectric vibrator is used to generate a piezoelectric signal under the vibration or impact of the scraper operation. The piezoelectric signal is used to characterize the vibration amplitude, frequency components or impact characteristics during the scraper operation. The signal acquisition and processing module is connected to the scraper thickness measurement unit and the scraper vibration state measurement unit, respectively. The thickness inversion and state recognition module is connected to the signal acquisition and processing module. The thickness inversion and state recognition module stores a preset mapping relationship or inversion model, which is used to calculate the remaining thickness and operating state of the scraper based on the features extracted from the acquired thermoelectric and piezoelectric signals. The wireless communication module is connected to the signal acquisition and processing module and the thickness inversion and status recognition module, and is used to wirelessly transmit the remaining thickness of the scraper, wear amount, operating vibration status, early warning information and sensor abnormality information to an external receiving terminal or downhole monitoring gateway. The power supply unit provides operating power to the entire monitoring device.

2. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 1, characterized in that, The scraper thickness measurement unit, scraper vibration state measurement unit, signal acquisition and processing module, and thickness inversion and state recognition module are installed in a flow guide box. An installation cavity is provided inside the scraper, and the flow guide box is embedded in the installation cavity.

3. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 2, characterized in that, The cold-end thermal management structure includes heat dissipation fins, which are located above the cantilever beam piezoelectric vibrator.

4. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 3, characterized in that, The cold-end thermal management structure also includes a flow guiding cavity; the flow guiding cavity is the internal cavity of the flow guiding box, and the flow guiding box is provided with an arc-shaped cover to form an arc-shaped flow guiding cavity inside the box, which is used to guide the air generated by the vibration of the free end of the cantilever beam piezoelectric vibrator to the cold end area to regulate the cold end temperature.

5. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 4, characterized in that, The free end of the cantilever beam piezoelectric vibrator is equipped with a permanent magnet.

6. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 5, characterized in that, The scraper vibration state measurement unit also includes a tuning component, which includes a piezoelectric vibrator spacing adjustment mechanism. The piezoelectric vibrator spacing adjustment mechanism includes a mounting plate, sliders, springs, a first drive motor, and a first lead screw. A slide rail is provided on the mounting plate, and multiple sliders are embedded in the slide rail and can slide back and forth along the slide rail. One end of the cantilever beam piezoelectric vibrator is fixedly connected to the slider, and the spring is located between two adjacent sliders and fixedly connected to the slider. The spacing between the sliders is equal. The bottoms of the two first drive motors are respectively fixed to the two ends of the mounting plate, and the first drive motors are shaft-connected to the first lead screw. A through threaded hole is provided in the middle of the outermost slider, and the first lead screw is threadedly connected to the threaded hole.

7. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 6, characterized in that, The tuning assembly also includes a piezoelectric vibrator amplitude adjustment mechanism, which includes a second drive motor, a second lead screw, and an adjustment plate. The adjustment plate has a slot through which all cantilever beam piezoelectric vibrators pass. The adjustment plate is fixedly connected to the second lead screw. Driven by the second drive motor, the adjustment plate controls the clamping position on the cantilever beam piezoelectric vibrator to adjust its vibration amplitude.

8. The embedded wireless monitoring device for wear and operating status of scraper conveyors according to claim 7, characterized in that, The thickness inversion and state recognition module has a pre-stored database or inversion model of the mapping relationship between thermoelectric response characteristics, vibration state characteristics and scraper remaining thickness. It obtains the current scraper remaining thickness, wear amount and operating vibration state through table lookup, interpolation, regression calculation, data fusion or machine learning recognition methods.

9. An embedded wireless monitoring method for wear and operating status of a scraper conveyor, based on the embedded wireless monitoring device for wear and operating status of a scraper conveyor as described in claim 8, characterized in that, Includes the following steps: Step S1: Before the scraper runs, record the initial thickness of the scraper, the minimum allowable remaining thickness, the initial output parameters of the thermoelectric conversion element, and the initial spacing and initial clamping position of the cantilever beam piezoelectric vibrator. Step S2: During the operation of the scraper, the wear area of ​​the scraper generates heat through friction with the central groove, chain and conveyed material. The heat is transferred to the hot end of the thermoelectric conversion element through the scraper body and heat transfer components. At the same time, the cold end of the thermoelectric conversion element is regulated by the cold end thermal management structure to form a temperature difference between the hot end and cold end of the thermoelectric conversion element that is related to the remaining thickness of the scraper, and a thermoelectric signal is output. The piezoelectric signals generated by the cantilever beam piezoelectric vibrator under the vibration of the scraper are acquired synchronously, and the thermoelectric and piezoelectric signals are time-stamped. Step S3: Within the preset sampling window, calculate one or more parameters from the current vibration amplitude, peak-to-peak value, root mean square value, main frequency, frequency band energy, signal-to-noise ratio, and output saturation state based on the acquired piezoelectric signal; when the piezoelectric signal is lower than the preset effective threshold, exceeds the range of the acquisition circuit, the main frequency deviates from the target frequency band, or the signal-to-noise ratio is lower than the preset threshold, generate a tuning command. Step S4: According to the tuning command, the response characteristics of the scraper vibration state measurement unit are adjusted using the tuning component; wherein, the spacing between adjacent cantilever beam piezoelectric vibrators is changed by the piezoelectric vibrator spacing adjustment mechanism to adjust the coupling state and response frequency band of the piezoelectric vibrator array; the effective vibration length or clamping position of the cantilever beam piezoelectric vibrator is changed by the piezoelectric vibrator amplitude adjustment mechanism to adjust its vibration amplitude, natural frequency and output sensitivity; after the adjustment is completed, the tuning component is locked. Step S5: The thermoelectric signal and piezoelectric signal are amplified, filtered, converted from analog to digital, and outlier removed by the signal acquisition and processing module; one or more thermal response features are extracted from the thermoelectric signal, including steady-state thermoelectric voltage, transient voltage change rate, equivalent hot and cold junction temperature difference, and temperature rise response time; one or more vibration state features are extracted from the piezoelectric signal, including vibration amplitude, peak-to-peak value, root mean square value, dominant frequency, frequency band energy, impact factor, and kurtosis. Step S6: Identify the current operating vibration state of the scraper based on the vibration state characteristics, and input the vibration state characteristics as the working condition compensation quantity into the thickness inversion and state identification module; The thickness inversion and state identification module calculates the current scraper remaining thickness by calling the preset thermoelectric response characteristics-vibration state characteristics-scraper remaining thickness mapping relationship or inversion model based on the thermal response characteristics and vibration state characteristics. Step S7: Calculate the scraper wear based on the initial scraper thickness and the current remaining scraper thickness, and output the scraper wear status, operating vibration status, and early warning information based on one or more of the following results: remaining scraper thickness, wear amount, wear change trend, and operating vibration status.

10. The embedded wireless monitoring method for wear and operating status of a scraper conveyor according to claim 9, characterized in that, In step S6, the establishment of the mapping relationship or inversion model between thermoelectric response characteristics, vibration state characteristics, and remaining scraper thickness includes the following steps: Step S61: Based on the scraper model, material, initial thickness and allowable wear limit, divide the remaining thickness of the scraper into multiple thickness levels to form a scraper remaining thickness sample set; Step S62: Establish multiple operating condition samples based on one or more parameters of the scraper conveyor, such as operating speed, load size, material state, impact intensity, and environmental heat dissipation conditions. Step S63: Under different scraper remaining thickness levels and different operating conditions, collect the thermoelectric signals output by the thermoelectric conversion element and the piezoelectric signals output by the cantilever beam piezoelectric vibrator, and extract the corresponding thermal response characteristics and vibration state characteristics. Step S64: Establish a correspondence between the remaining thickness of the scraper, thermal response characteristics and vibration state characteristics to form a mapping relationship database, or establish a regression model, interpolation model, data fusion model or machine learning inversion model based on the correspondence. Step S65: During the actual operation of the scraper, the real-time thermal response characteristics and vibration state characteristics are input into the mapping database or inversion model. The vibration state characteristics are used to compensate for the deviation of the thermoelectric signal caused by the change of operating conditions, and the corrected remaining thickness of the scraper is obtained.

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