Self-responsive coating system with embedded sensors and application to phosphating process pump shaft sleeves

Abstract

The application discloses a self-response coating system with embedded sensing and application to a phosphating chemical pump shaft sleeve, and belongs to the technical field of embedded sensing systems. In view of the special operation condition and structure of the shaft sleeve, a multi-mode MEMS series packaged sensor is embedded in the coating on the shaft sleeve, especially the inner wall of the shaft sleeve, data fusion interaction is formed between the multi-mode sensing groups, multi-dimensional state monitoring is performed on the blind area dynamic structure of the shaft sleeve, and timely response is made. Timely and accurate response prompts are provided for operation and maintenance of the shaft sleeve. Serious coating loss caused by insufficient monitoring is avoided, and finally, the pump body workpiece is scrapped. The problem that the coating of the chemical pump workpiece dynamic structure at the blind area position cannot be effectively monitored and timely responded is solved.

Description

Technical Field

[0001] This invention belongs to the field of embedded sensing system technology, specifically relating to a self-responsive coating system with embedded sensing and its application in the shaft sleeve of a phosphate chemical pump. Background Technology

[0002] Phosphate chemical pumps are specialized equipment used in phosphate chemical production to transport acidic, corrosive, or abrasive media. Due to the special properties of the media, the pump casing and flow-through components of phosphate chemical pumps require an anti-wear and corrosion-resistant coating. This ensures effective physical isolation between the pump components and the media, preventing any impact on the structural stability of the pump components and ensuring stable operation, thus extending the pump's service life. After the coating material is sprayed, it forms a coating on the surface of the pump components through intermolecular forces. However, as the pump operates under complex conditions for an extended period, the coating will experience fatigue wear, leading to micro-cracks on the coating surface. During pump operation, friction between the pump body itself and the medium and the pump body can cause the workpiece temperature to rise. Excessive temperature can affect the stability of the coating tension and easily lead to the aforementioned micro-cracks. Especially for the shaft sleeve of a chemical pump, as a vulnerable component, it protects the pump shaft and bears the main friction and wear. Under operating conditions, its surface temperature often rises and falls rapidly, which can easily lead to deformation and cracking of the coating. The fitting structure of the shaft sleeve on the pump body creates a blind zone at the contact surface with the pump shaft, making it even more difficult to monitor defects in the surface coating. Due to the omission of defects, irreversible physical damage can eventually occur between the shaft sleeve and the pump shaft due to wear, resulting in scrapped parts. Summary of the Invention

[0003] This invention provides a self-responsive coating system with embedded sensors, applied to the bushing of a phosphate chemical pump. Addressing the unique operating conditions and structure of the bushing, multi-modal MEMS-encapsulated sensors are embedded within the coating, particularly on the inner wall of the bushing. These sensors fuse and interact with each other, enabling multi-dimensional state monitoring of the moving structure within the bushing's blind zone and providing timely responses. This provides timely and accurate feedback for maintenance at the bushing, preventing severe coating wear due to inadequate monitoring, which could ultimately lead to pump component failure. This solves the problem of ineffective monitoring and timely response to coating issues in moving structures within blind zones of chemical pump components.

[0004] To achieve the above-mentioned technical objectives, the present invention is implemented through the following technical solution: A self-responsive coating system with embedded sensing, comprising: The sensor data acquisition module includes at least: a physical quantity sensing unit, a chemical quantity sensing unit, and a structural quantity sensing unit; The physical quantity sensing unit is used to monitor the temperature and deformation of the coating. The chemical quantity sensing unit is used to monitor the intrusion of corrosive elements into the coating; The structural quantity sensing unit is used to monitor cracks in the coating structure. The MCU module is used to preprocess the raw physical, chemical, and structural data of the coating; analyze the current physical, chemical, and structural state of the coating based on the preprocessed data; and provide a terminal response based on the analysis results. The communication transmission module includes at least: an internal sensing communication unit and an external transmission communication unit; the internal sensing communication unit is used for interactive communication between various groups of sensors within the coating; the external transmission communication unit is used for establishing interactive communication between the sensor group and an external MCU module. A power supply module, located in the middle layer of the coating, is used to provide power to the sensor data acquisition module and the communication transmission module.

[0005] Preferably, the physical quantity sensing unit includes a MEMS strain gauge, which is used to monitor the coating strain pressure and to detect whether the coating has peeled off or exceeded the threshold wear. It also includes a MEMS thermal sensor for monitoring coating temperature changes; the MEMS thermal sensor is packaged using a thermocouple or a thermistor. The chemical quantity sensing unit is disposed within the coating and includes: a MEMS electrochemical sensor, a pH-sensitive microelectrode, and a gas sensing chip; The structural quantity sensing unit includes a flexible graphene thin film antenna sensor, which is particularly suitable for monitoring cracks on curved surfaces.

[0006] Preferably, the MCU module has at least one set of memory, and the memory has a preset raw data preprocessing execution program to perform data preprocessing operations on the raw data, including at least noise reduction, analog-to-digital conversion and amplification. The memory contains preset pressure threshold data, temperature threshold data, chemical ion concentration threshold data, and pH threshold data; it also contains a preset threshold comparison execution program that includes at least all of the above monitoring items.

[0007] Preferably, the MCU module further includes a timing control unit, which divides different sampling channels according to the sensor sampling frequency to avoid signal interference between multiple groups of sensors; For high-frequency monitoring sensors, including those for monitoring deformation and corrosive element intrusion, the sampling frequency is set to 10Hz. For low-frequency monitoring sensors, including those monitoring temperature, pH, and corrosive gases, the sampling frequency is set to 1Hz.

[0008] Preferably, the MCU module further includes a data fusion and interaction unit, which is used to effectively determine and coordinate the data collected by the sensor group. The validity determination is based on similar sensors, with at least three adjacent groups forming a determination group. If the deviation between the data collected by the three groups of sensors is less than 5%, then all three groups of data are determined to be valid data; otherwise, all three groups of data are considered outliers and need to be collected again. The data collaboration is based on cross-type sensors, and evaluates the current coating condition based on data collected by at least two types of sensors, thus avoiding the one-sided situation caused by evaluation by a single sensor. The effective determination and data collaboration in the data fusion interaction unit are accomplished based on the construction of a lightweight CNN-LSTM neural network model.

[0009] Preferably, the MCU module further includes a sensor coordination and linkage unit. Based on the correlation between abnormal coating conditions, the sensor coordination and linkage unit triggers the associated sensors to increase their acquisition frequency and enter a sensitive acquisition mode when one type of sensor detects an abnormality.

[0010] Preferably, the internal sensing and communication unit includes electrical wires and a sensor-end communication transceiver module; the sensor groups are connected by ultra-fine data wires to realize the interaction between the sensor groups; the ultra-fine data wires are distributed in the middle layer structure of the coating, and the ultra-fine data wires with several mesh branches are connected to the sensor-end communication transceiver module; The external transmission communication unit includes an external response terminal communication transceiver module.

[0011] Preferably, the sensor groups in the physical quantity sensing unit, chemical quantity sensing unit and structural quantity sensing unit are connected to the workpiece using a non-destructive embedding process, which includes at least: in-situ coating and laser implantation. The in-situ coating involves arranging each sensor group at a designated position on the tooling surface and simultaneously forming each sensor group with the coating through spraying or casting processes. Laser implantation involves using an ultrashort pulse laser to create a micron-sized shallow groove on the surface of a cured coating. After implanting the MEMS sensor, the groove is then sprayed with the same material to cover the sensor.

[0012] Preferably, a miniature relay node (passive RFID relay) is set in the coating to reduce the packet loss rate and extend the communication distance between sensor components on the workpiece, thereby expanding the coverage area of ​​the network.

[0013] Preferably, the MEMS strain gauge packaging structure uses a silicon-based strain gauge as the sensing element; an elastomer substrate is disposed on the contact side between the silicon-based strain gauge and the monitoring element, the elastomer substrate transmits external stress to the strain gauge and provides mechanical support force, and the elastomer substrate material includes one of stainless steel, aluminum alloy and ceramic; an alloy material is used as the overall protective shell; the chip electrodes are electrically connected to the internal circuit board by gold wire bonding, and the signal leads are led out from the side wall of the protective shell; the thickness is 10~50um; The packaging structure of the MEMS thermal sensor based on thermocouples is as follows: a silicon nitride or silicon dioxide insulating layer is deposited on a silicon substrate to form a wafer; the thermal sensor based on thermocouples generates a thermoelectric potential ΔV through the temperature difference at the connection of two different conductors A and B, and the temperature difference is calculated by measuring the voltage. Therefore, conductor A and insulator B are alternately used on the wafer surface to form conductor patterns through photolithography and etching; a suspended film is etched on the silicon substrate, with the hot end suspended; the thermopile is connected to the external pads by wire bonding; an alloy material is used as the packaging shell structure to maintain an internal vacuum inert environment; Thermistor thermal sensors utilize the significant change in resistance of semiconductor materials with temperature, mapping temperature by measuring the resistance value. The packaging structure of the MEMS thermal sensor formed by thermistors is as follows: a thin-film resistor with a thickness of less than 1 μm is used as the thermistor element and integrated on a substrate; silicon dioxide or silicon nitride is used as an electrically insulating layer to cover and protect the thermistor element; aluminum metal contacts are used as external circuit connection electrodes; and epoxy resin is used as the entire encapsulation shell protective layer. The packaging structure of the MEMS electrochemical sensor is as follows: a silicon dioxide insulating layer is formed by thermal oxidation growth on a silicon substrate; an electrode pattern is formed by photolithography or etching; a second insulating layer is deposited and a window is created by photolithography, reserving a working electrode area; a reference electrode is fabricated using Ag / AgCl; microcavities and channels are etched on the upper chip to a depth of 50~200μm; the upper and lower chips are aligned and bonded, forming a microcavity between the upper and lower chips as a reaction liquid storage cavity; pads are prepared at the chip edges, and the chip is connected to the substrate by wire bonding; an alloy is used to make a protective encapsulation shell, with leads connected to an external interface; a liquid interface is reserved on the shell, communicating with the microcavity. The gas sensing chip, based on the MEMS electrochemical sensor, has an air inlet in the microcavity and is covered with a breathable membrane, allowing only gas to enter while preventing particulate solids from passing through. The pH-sensitive microelectrode can be directly selected as a finished product for packaging and use. The flexible graphene thin-film antenna sensor is selected for packaging and use from a finished product.

[0014] Another object of the present invention is to provide an application of a self-responsive coating system with embedded sensing on a phosphate chemical pump shaft sleeve, comprising: The sensor array structure consists of a single MEMS strain gauge, a MEMS thermal sensor, a MEMS electrochemical sensor, a gas sensing chip, a pH-sensitive microelectrode, and a flexible graphene thin film antenna sensor forming a fusion sensing array unit. Each single sensor is arranged in a rectangular or circular array within the fusion sensing array unit, forming a square or circular fusion sensing array unit. The fusion sensor array units are arranged in rows along the axial direction of the bushing; the spacing between two adjacent rows of the fusion sensor array units is set to 3~8mm, and the spacing between two adjacent groups of the fusion sensor array units in the same row is set to 5~10mm; an array structure in which multiple sensors are arranged uniformly and circumferentially along the bushing is adopted to avoid single-point sensors being subjected to concentrated centrifugal force, and the monitoring reliability can be improved through multi-sensor data redundancy verification. The sensor assembly and coating are formed by in-situ coating. On the inner wall of the bushing, each individual sensor assembly is first arranged as a fusion sensing array unit, and then each fusion sensing array unit is arranged in sequence. The sensor assembly and coating are fused together by in-situ coating. The communication transceiver module of the sensor end set on the inner wall of the bushing adopts the Lora wireless communication module; the communication transceiver module set on the response terminal also adopts the Lora wireless communication module.

[0015] Preferably, before the in-situ coating, a coating with a thickness of not less than 0.2 mm is sprayed onto the inner wall surface of the bushing, the sensor assembly is placed on the coating, and then in-situ coating is performed to fuse the sensor assembly with the coating; the embedment depth of the sensor assembly is controlled at 1 / 2 to 1 / 3 of the coating thickness; this ensures that the sensor is not exposed by early wear, and also uses the overall structure of the coating to constrain the sensor and reduce the interface stress caused by centrifugal force; for the arc-shaped bushing, the optimal embedding position is determined by simulating the centrifugal stress distribution at different embedment depths.

[0016] Preferably, an elastic buffer layer with a thickness of 30~100um is prepared between the MEMS strain gauge, MEMS thermal sensor, MEMS electrochemical sensor, gas sensing chip, pH-sensitive microelectrode, and flexible graphene thin film antenna sensor and the coating. The elastic modulus of the elastic buffer layer is between that of the sensor encapsulation layer and the wear-resistant coating of the bushing. During vibration, the interfacial stress between the workpiece and the sensor can be buffered by the elastic buffer layer, avoiding coating cracking and sensor debonding caused by sudden changes in modulus. At the same time, the elastic buffer layer fills the small gap between the sensor and the coating, eliminates micro-slippage of the contact interface during vibration, and prevents signal distortion due to poor contact.

[0017] The beneficial effects of this invention are: This invention provides a self-responsive coating system with embedded sensors, and applies it to the monitoring of the coating condition of the inner wall of a phosphate chemical pump shaft sleeve. By introducing MEMS-encapsulated sensors, which are directly encapsulated in the inner wall coating of the shaft sleeve through in-situ coating, the integrated embedded sensor group monitors the working condition of the shaft sleeve coating in real time. The miniature multimodal sensor group is located within the coating, and the dynamic contact between the shaft sleeve and the shaft does not interfere with the sensor group. The inner wall of the shaft sleeve is a blind zone structure, and the dynamic contact friction between the inner wall of the shaft sleeve and the shaft, as well as the heat rise after friction, can easily affect the structural stability of the inner wall coating, leading to wear, peeling, microcracks, and other anomalies. The multimodal sensor group provides a quantifiable and intuitive working condition monitoring scenario for the blind zone of the inner wall of the shaft sleeve, which can capture subtle working condition anomalies of the inner wall coating of the shaft sleeve, and provide timely and effective feedback support for the operation and maintenance of the moving structure of the shaft sleeve. For the special operating scenarios of rotation, centrifugation, and vibration at the bushing, an in-situ coating process is selected to integrate the sensor group with the coating at different depths and control the depth position. Combined with the LoRa communication transmission system, the interference of rotation, centrifugation, and vibration on the sensor group's capture accuracy and signal transmission is reduced. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the unfolded inner wall of the bushing of the present invention and the arrangement of the fusion sensor array units thereon; Figure 2 This is a schematic diagram of the sensor group arrangement inside the coating on the inner wall of the bushing of the present invention.

[0020] In the attached diagram, the structural names represented by each number are as follows: 1-Fusion sensor array unit, 2-Workpiece, 3-Coating, 4-Sensor group. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0022] A self-responsive coating system with embedded sensing includes: a sensing data acquisition module, which in this embodiment monitors the physical, chemical, and structural conditions of the coating, and sets up [specific sensors / mechanisms] accordingly. MEMS strain gauges are used to monitor coating strain and pressure, indicating whether the coating has detached or experienced excessive wear. The MEMS is encapsulated under the coating, accurately capturing the mechanical pressure exerted on it by the coating above. When the coating detaches or experiences excessive wear, the stress will change abruptly beyond the threshold. The MEMS strain gauge encapsulation structure uses a silicon-based strain gauge as the sensing element. An elastomer substrate is placed on the contact side between the silicon-based strain gauge and the monitoring element. The elastomer substrate transmits external stress to the strain gauge and provides mechanical support. The elastomer substrate is made of aluminum alloy. An alloy material is used as the overall protective shell. The chip electrodes are electrically connected to the internal circuit board via gold wire bonding, and signal leads are led out from the sidewall of the protective shell. MEMS thermal sensors are installed to monitor coating temperature changes. For dynamic workpieces such as bushings, friction between workpieces causes a sudden increase in temperature. Sudden changes in workpiece surface temperature can easily cause sudden changes in coating stress, resulting in coating peeling or cracking. This embodiment provides two modes of thermal sensors: thermocouple and thermistor. The packaging structure of a MEMS thermal sensor based on a thermocouple is as follows: a silicon nitride or silicon dioxide insulating layer is deposited on a silicon substrate to form a wafer; the thermocouple-based thermal sensor generates a thermoelectric potential ΔV through the temperature difference at the connection point of two different conductors A and B, and the temperature difference is calculated by measuring the voltage. Therefore, conductor A and insulator B are alternately used on the wafer surface to form conductor patterns through photolithography and etching; a suspended film is etched on the silicon substrate, with the hot end suspended; the thermopile is connected to the external pads by wire bonding; an alloy material is used as the packaging shell structure to maintain an internal vacuum inert environment; Thermistor thermal sensors utilize the significant change in resistance of semiconductor materials with temperature, mapping temperature by measuring the resistance value. The packaging structure of a MEMS thermal sensor formed by a thermistor is as follows: a thin-film resistor with a thickness of less than 1 μm is used as the thermistor element and integrated on a substrate; silicon dioxide or silicon nitride is used as an electrically insulating layer to cover and protect the thermistor element; aluminum metal contacts are used as external circuit connection electrodes; and epoxy resin is used as the entire encapsulation shell protective layer. A MEMS electrochemical sensor is set up to capture corrosive ions, including chloride, fluoride, sulfate, and hydrogen ions. Chemical pumps typically transport corrosive media, so a coating is applied to the pump body to isolate it from the corrosive fluid. When the MEMS electrochemical sensor can capture corrosive ions, it indicates that the coating has microcracked or peeled off, causing an abnormal signal change in the sensor. The MEMS electrochemical sensor's packaging structure involves: thermally oxidizing and growing a silicon dioxide insulating layer on a silicon substrate; forming an electrode pattern through photolithography or etching; depositing a second insulating layer and photolithographically creating windows to reserve the working electrode area. A reference electrode is fabricated using Ag / AgCl. Microcavities and channels are etched onto the upper chip to a depth of 100 μm. The upper and lower chips are aligned and bonded together, forming a microcavity between them as a storage chamber for the reaction solution. The reaction solution is set according to the corrosive elements in the fluid medium. The purpose is to generate a chemical reaction upon contact with the fluid medium, resulting in a potential difference that forms a monitoring signal. The principle of the chemical element monitoring sensor is existing technology and will not be described in detail here. Pads are fabricated at the chip edges, and the chip is connected to the substrate via wire bonding. An alloy is used to create a protective encapsulation shell, with leads connecting to an external interface. A liquid interface is pre-installed on the shell, communicating with the microcavity. A pH-sensitive microelectrode is set up to capture changes in pH value. The purpose is to work in conjunction with the MEMS electrochemical sensor to detect and warn of the intrusion of corrosive media. A gas sensing chip is used to capture corrosive ions in diffused corrosive gases. Since most fluid media are volatile, the diffused gases are also corrosive. If the coating density is uneven or too low, or if the coating process is substandard, gas can pass through the micropores in the coating structure and reach the gas sensing chip. Therefore, the gas sensing chip can not only detect abnormal operating conditions of the coating but also react to the structural conditions of the coating itself, responding to substandard coatings. Based on MEMS electrochemical sensors, the gas sensing chip has an inlet hole in the microcavity covered with a breathable membrane, allowing only gas to enter while preventing the passage of particulate solids. A flexible graphene film antenna sensor is set up to monitor microcrack anomalies in the coating; the microcracks in the coating are responded to by monitoring the resonant changes of the flexible graphene film antenna sensor caused by crack propagation. Currently, MEMS chip packaging technology has been developed into products. For example, MEMS strain gauge sensors can be selected from the MEMS electrochemical sensors, MEMS gas sensors, and other MEMS series developed by FaradalC. Flexible graphene thin film antenna sensors and pH-sensitive microelectrodes are also existing technology products. The system also includes an MCU module, which contains at least one set of memory. The memory contains a raw data preprocessing execution program that performs noise reduction, analog-to-digital conversion, and amplification on the raw data using smoothing filtering or transform domain denoising techniques. The memory also contains a preset threshold comparison execution program, which includes multimodal sensing and monitoring items. Pressure threshold data, temperature threshold data, chemical ion concentration threshold data, and pH threshold data are substituted into this execution program as execution program elements. The input real-time monitoring data is compared with the threshold data to detect whether there are any abnormalities in the coating conditions. For monitoring workpieces, single-point, single-modal monitoring is insufficient to reflect the working condition of the entire workpiece area. Therefore, this embodiment sets up multimodal sensing monitoring. Furthermore, based on the multimodal sensor group, it should be arranged in a regular array on the workpiece to ensure that the multimodal sensor group can cover the entire workpiece area. However, integrating multiple types of sensors with different frequencies onto the same workpiece can easily lead to signal interference between sensor groups, affecting the accuracy of the original monitoring signal. This embodiment divides different sampling channels according to the sampling frequency of different types of sensors, using frequency division multiplexing technology to divide them into different channels based on the different sampling frequencies of the sensors, while still achieving synchronous transmission. For example: For high-frequency monitoring sensors, including MEMS strain gauge sensors and MEMS electrochemical sensors, the sampling frequency is set to 10Hz; for low-frequency monitoring sensors, including MEMS thermal sensors, pH-sensitive microelectrodes, and MEMS gas sensors, the sampling frequency is set to 1Hz. The multimodal sensor groups set in this embodiment have a mutual mapping relationship. For example, a sudden rise or fall in temperature may cause changes in the molecular structure of the coating, resulting in the coating exceeding the threshold for wear, peeling, or microcracks. Peeling or microcracks in the coating can lead to the infiltration of fluid media, causing responses from electrochemical sensors, gas sensors, and pH-sensitive microelectrodes. Therefore, a lightweight CNN-STM neural network model is built in the MCU module to realize the fusion and interaction of multimodal sensor data, mainly to complete the effective judgment of data and the data collaboration between different modal sensors; The valid determination is based on similar sensors. In this embodiment, three adjacent sets of similar sensors are set up as a judgment group. The deviation between the data collected by the three sets of sensors should be less than 5%. If the deviation is less than 5%, the three sets of data are judged to be valid data. Otherwise, the three sets of data are considered as outliers and need to be collected in the next round. Data collaboration is based on cross-type sensors. This embodiment demonstrates the evaluation of the current coating condition based on the collaboration of two types of sensors. For example, a MEMS thermal sensor monitors and senses sudden temperature changes in the coating. When the temperature exceeds the threshold, a MEMS strain gauge sensor is used in conjunction to monitor and respond to conditions such as coating peeling or excessive wear. Alternatively, a flexible graphene thin film antenna sensor can be used in conjunction to monitor and respond to micro-cracks in the coating. This avoids the possibility of biased monitoring caused by a single sensor, especially for sensing items such as temperature, which can only be considered as an influencing factor. The structure and training of the aforementioned lightweight CNN-LSTM neural network model are as follows: The model includes a branch for sensors of the same class that completes effective determination under the feature fusion layer, and a branch for sensors of different classes that complete data collaboration. Input layer structure:

[0023] Data preprocessing 1) Data labeling: Compare three groups of adjacent sensors of the same type. If the deviation of each pair of comparisons is less than 5%, it is labeled as 1; otherwise, it is labeled as 0. 2) Coating condition assessment and labeling: Label the abnormal and normal conditions of the monitoring items of different types of sensors separately; 3) Remove outliers and normalize the data; 4) Divide the data into training, validation, and test sets in a ratio of 7:2:1; Model training Validity criterion: Binary cross-entropy, with a learning bias of less than 5% as the criterion; Performance evaluation: Sparse classification cross-entropy, adapted to integer labeling; Total loss: 0.4 * effective judgment loss + 0.6 * working condition assessment loss; Model training and validation can be performed by those skilled in the art based on the model structure, and the relevant program code and process will not be described in detail here. As a preferred implementation, the MCU module also includes a sensor coordination and linkage unit. Based on the fusion and interaction of the multimodal sensor data, if sensor A detects an anomaly in its data, it can simultaneously coordinate with sensor B for fusion and interactive monitoring. At this time, the sensor coordination and linkage unit can trigger the associated sensor B to increase its sampling frequency and enter a sensitive sampling mode, thereby improving the accuracy of the collaborative interaction. The regulation of the sensor frequency mainly relies on the sensor front-end circuit, using a high-speed analog-to-digital converter to quickly convert analog signals into digital signals, which is the basic step to achieve a high sampling rate. At the same time, the design of the amplifier and filter signal conditioning circuits needs to support a wider bandwidth to avoid signal delay or distortion. For example, when the strain sensor in a certain area of ​​the coating detects that the stress exceeds the threshold, it will simultaneously trigger the flexible graphene film antenna sensor in that area to increase its frequency and enter a high-sensitivity mode to accurately locate the crack propagation path; if the electrochemical sensor detects the intrusion of the medium, it will link with the surrounding thermal sensors to monitor whether there is a corrosion exothermic phenomenon. If both conditions are met, a wireless early warning will be directly activated to avoid local corrosion perforation. The sensor data acquisition module and the MCU module of this system realize data transmission and interaction through the communication module; in addition to the external transmission communication unit, the communication module of this system also has an internal sensor communication unit, which can complete the interaction between sensor groups. As a preferred embodiment, a passive RFID micro relay node is set in the coating to reduce the packet loss rate and extend the communication distance between sensor components on the workpiece, thereby expanding the coverage network range. The internal sensing and communication unit includes electrical wires and a sensor-end communication transceiver module. The communication transceiver module is a Wi-Fi, LoRa, or Bluetooth patch communication module, or it can be set as an RFID radio frequency chip. The sensor groups are connected by ultra-fine data wires to realize the interaction between the sensor groups and form an interactive network at the sensor end. The ultra-fine data wires are distributed in the middle layer structure of the coating, and several mesh branches of ultra-fine data wires are converged to the sensor-end communication transceiver module. The external transmission communication unit includes a response terminal communication transceiver module, which can also be a Wi-Fi, LoRa, or Bluetooth patch communication module, or an RFID radio frequency chip. The system also includes a power supply module, located in the middle layer of the coating, which provides power to the sensor data acquisition module and the communication transmission module. The power supply module uses NGK EnerCera series lithium polymer soft-pack batteries with a thickness of 0.45~1.0mm, and the thinnest can be 0.45mm, which meets the requirements of embedding in the coating substrate. Example

[0024] Based on Example 1, this example provides two methods for embedding and encapsulating a sensor array within a sensor array: 1) In-situ coating: Arrange each sensor group at a designated position on the tooling surface, and achieve synchronous forming between each sensor group and the coating through spraying or casting process; 2) Laser implantation: Micron-level shallow grooves are prepared on the surface of the cured coating using an ultrashort pulse laser. After the sensor is implanted, the groove opening is sprayed with the same material to cover the sensor. Example

[0025] Based on the self-responsive coating system with embedded sensing provided in Embodiments 1 and 2, this embodiment applies it to the bushing of a phosphate chemical pump, and more specifically, it is more valuable to apply it to the inner wall of the bushing; this embodiment takes the 100fvh-40-k pump bushing as an example, with a length of 40mm, an inner diameter of 10mm, and an outer diameter of 20mm. For the application scenarios of bushings, based on Embodiment 1 and Embodiment 2, targeted improvements are made in the following aspects: Sensor array structure, such as Figure 1 As shown, a fusion sensing array unit 1 is formed by a single set of MEMS strain gauges, MEMS thermal sensors, MEMS electrochemical sensors, gas sensing chips, pH-sensitive microelectrodes, and flexible graphene thin film antenna sensors; each single set of sensors is arranged in a circular array within the fusion sensing array unit 1 to form a circular structure fusion sensing array unit 1. The fusion sensor array units 1 are arranged in rows along the axial direction of the bushing workpiece 2; the spacing between two adjacent rows of fusion sensor array units 1 is set to 5mm, and the spacing between two adjacent sets of fusion sensor array units 1 in the same row is set to 8mm; the array structure of multiple sensors is uniformly arranged in a circumferential manner along the bushing to avoid the single sensor being subjected to concentrated force due to centrifugal force, and the monitoring reliability can be improved through multi-sensor data redundancy verification. The sensor assembly and coating are formed using in-situ coating. On the inner wall of the bushing, each individual sensor assembly is first arranged as a fusion sensing array unit, and then each fusion sensing array unit is arranged sequentially. The sensor assembly and coating are fused together through in-situ coating. In-situ covering facilitates seamless fusion between the sensor assembly and the coating, and is more suitable for adapting to rotational centrifugal force and vibration under the working conditions of bushing movement. It also improves the embedding stability of the sensor assembly and ensures that the sensing accuracy is minimized. The communication transceiver module of the sensor end set on the inner wall of the bushing adopts the Lora wireless communication module; the communication transceiver module set on the response terminal also adopts the Lora wireless communication module; compared with Wi-Fi or Bluetooth, the Lora standard has the least attenuation when penetrating the coating obstacle, reducing signal attenuation and loss. As a preferred embodiment, such as Figure 2 As shown, before in-situ coating, a coating with a thickness of not less than 0.2 mm is sprayed onto the inner wall surface of the bushing workpiece 2. The sensor assembly 4 is then placed on this coating, and in-situ coating is performed to fuse the sensor assembly 4 with the coating 3. By adjusting the coating thickness or the thickness of the coating itself, the embedment depth of the sensor assembly is controlled at 1 / 2 to 1 / 3 of the coating thickness. This ensures that the sensor assembly 4 is not exposed by early wear, and also uses the overall structure of the coating 3 to constrain the sensor assembly 4, reducing the interface stress caused by centrifugal force. In a preferred embodiment, an elastic buffer layer is prepared between the MEMS strain gauge, MEMS thermal sensor, MEMS electrochemical sensor, gas sensing chip, pH-sensitive microelectrode, and flexible graphene thin film antenna sensor and the coating. This embodiment provides two structures: a polyurethane elastic buffer layer or an epoxy elastic buffer layer, with a thickness of 50 μm. The elastic modulus of the elastic buffer layer is between that of the sensor encapsulation layer and the wear-resistant coating of the bushing. During vibration, the interfacial stress between the workpiece and the sensor can be buffered by the elastic buffer layer, avoiding coating cracking and sensor debonding caused by sudden changes in modulus. At the same time, the elastic buffer layer fills the tiny gap between the sensor and the coating, eliminates micro-slippage of the contact interface during vibration, and prevents signal distortion due to poor contact.

Claims

1. A self-responsive coating system with embedded sensing, characterized in that, include: The sensor data acquisition module includes at least: a physical quantity sensing unit, a chemical quantity sensing unit, and a structural quantity sensing unit; The physical quantity sensing unit is used to monitor the temperature and deformation of the coating; the physical quantity sensing unit includes a MEMS strain gauge, which is used to monitor the coating strain pressure; It also includes a MEMS thermal sensor, which is used to monitor changes in coating temperature; The chemical quantity sensing unit is used to monitor the intrusion of corrosive elements into the coating; the chemical quantity sensing unit is disposed within the coating and includes: a MEMS electrochemical sensor, a pH-sensitive microelectrode, and a gas sensing chip; The structural quantity sensing unit is used to monitor cracks in the coating structure; the structural quantity sensing unit includes: a flexible graphene thin film antenna sensor. A fusion sensing array unit is formed by combining a single MEMS strain gauge, a MEMS thermal sensor, a MEMS electrochemical sensor, a gas sensing chip, a pH-sensitive microelectrode, and a flexible graphene thin film antenna sensor. Each single sensor is arranged in a rectangular array or a circular array within the fusion sensing array unit, forming a fusion sensing array unit with a square structure or a circular structure. The MCU module is used to preprocess the raw physical, chemical, and structural data of the coating; analyze the current physical, chemical, and structural state of the coating based on the preprocessed data; and provide a terminal response based on the analysis results. The MCU module also includes a data fusion and interaction unit, which is used to effectively determine and coordinate the data collected by the sensor group. The validity determination is based on similar sensors, with at least three adjacent groups forming a determination group. If the deviation between the data collected by the three groups of sensors is less than 5%, then all three groups of data are determined to be valid data; otherwise, all three groups of data are considered outliers. The data collaboration is based on cross-class sensors, and evaluates the current coating condition based on data collected by at least two types of sensors; The effective determination and data collaboration in the data fusion interaction unit are accomplished based on the construction of a lightweight CNN-LSTM neural network model; The MCU module also includes a sensor coordination and linkage unit. Based on the correlation between abnormal coating conditions, the sensor coordination and linkage unit triggers the associated sensors to increase the acquisition frequency and enter a sensitive acquisition mode when one type of sensor detects an abnormality. The communication transmission module includes at least: an internal sensing communication unit and an external transmission communication unit; the internal sensing communication unit is used for interactive communication between various groups of sensors within the coating; the external transmission communication unit is used for establishing interactive communication between the sensor group and an external MCU module. A power supply module, located in the middle layer of the coating, is used to provide power to the sensor data acquisition module and the communication transmission module.

2. The self-responsive coating system with embedded sensing according to claim 1, characterized in that, The MCU module also includes a timing control unit, which divides different sampling channels according to the sensor sampling frequency to avoid signal interference between multiple groups of sensors. For high-frequency monitoring sensors, including those for monitoring deformation and corrosive element intrusion, the sampling frequency is set to 10Hz. For low-frequency monitoring sensors, including those monitoring temperature, pH, and corrosive gases, the sampling frequency is set to 1Hz.

3. The self-responsive coating system with embedded sensing according to claim 1, characterized in that, The internal sensing and communication unit includes electrical wires and a sensor-end communication transceiver module; the sensor groups are connected by ultra-fine data wires to realize the interaction between the sensor groups; the ultra-fine data wires are distributed in the middle layer structure of the coating, and several mesh-branched ultra-fine data wires are converged to the sensor-end communication transceiver module; The external transmission communication unit includes an external response terminal communication transceiver module.

4. The self-responsive coating system with embedded sensing according to claim 1, characterized in that, The sensor groups in the physical quantity sensing unit, chemical quantity sensing unit and structural quantity sensing unit are connected to the workpiece using a non-destructive embedding process, which includes at least: in-situ coating and laser implantation. The in-situ coating involves arranging each sensor group at a designated position on the tooling surface and simultaneously forming each sensor group with the coating through spraying or casting processes. Laser implantation involves using an ultrashort pulse laser to create a micron-sized shallow groove on the surface of a cured coating. After implanting the MEMS sensor, the groove is then sprayed with the same material to cover the sensor.

5. The self-responsive coating system with embedded sensing according to claim 1, wherein the self-responsive coating system with embedded sensing is applied to the shaft sleeve of a phosphate chemical pump, characterized in that, The fusion sensor array units are arranged in rows along the axial direction of the bushing; the spacing between two adjacent rows of the fusion sensor array units is set to 3~8mm, and the spacing between two adjacent groups of the fusion sensor array units in the same row is set to 5~10mm. The sensor assembly and coating are formed by in-situ coating. On the inner wall of the bushing, each individual sensor assembly is first arranged as a fusion sensing array unit, and then each fusion sensing array unit is arranged in sequence. The sensor assembly and coating are fused together by in-situ coating. The communication transceiver module of the sensor end set on the inner wall of the bushing adopts the Lora wireless communication module; the communication transceiver module set on the response terminal also adopts the Lora wireless communication module.

6. The self-responsive coating system with embedded sensing according to claim 5, characterized in that, Before the in-situ coating, a coating with a thickness of not less than 0.2 mm is sprayed on the inner wall surface of the bushing. The sensor assembly is then placed on the coating, and then the in-situ coating is performed to fuse the sensor assembly with the coating. The burial depth of the sensor array is controlled at 1 / 2 to 1 / 3 of the coating thickness.

7. The self-responsive coating system with embedded sensing according to claim 1, characterized in that, An elastic buffer layer with a thickness of 30~100um is prepared between the MEMS strain gauge, MEMS thermal sensor, MEMS electrochemical sensor, gas sensing chip, pH sensitive microelectrode, and flexible graphene thin film antenna sensor and the coating. The elastic modulus of the elastic buffer layer is between that of the sensor encapsulation layer and the wear-resistant coating of the bushing.

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