Fastener monitoring method, system and device and storage medium

Abstract

The invention relates to the technical field of fasteners, and discloses a fastener monitoring method, system and device and a storage medium, and the method comprises the steps: installing a sensor on a fastener, and obtaining the resistance data collected by the sensor; performing conversion operation according to the resistance data to obtain a real-time resistance value; calculating according to the real-time resistance value to obtain a pre-tightening force; and judging according to the pre-tightening force to obtain a state monitoring result of the fastener. The method has the following effects that the state of the fastener can be monitored in real time, the potential loosening problem can be found and early warned in time, the equipment fault risk is reduced, and the operation efficiency and safety of equipment are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fasteners, and in particular to a fastener monitoring method, system, device and storage medium. Background Art

[0002] At present, in mechanical equipment, fasteners such as bolts, screws and screws are key components to ensure the stable operation of the equipment. As the use time increases, these fasteners may undergo plastic deformation, fatigue and wear due to high temperature, temperature difference, vibration, impact, corrosion, etc., which will reduce the preload of the fasteners, thereby affecting the safety performance and operation efficiency of the equipment. Therefore, it is necessary to regularly maintain or monitor the bolts, screws, screws, etc. of the equipment in order to understand the tightening status of these fasteners in real time.

[0003] In one prior art, due to poor accuracy of fastener detection caused by sensor failure, it can generally only meet the requirements of regular equipment maintenance. In some equipment that requires real-time monitoring of fastener tightness, most of them still adopt regular disassembly and manual detection methods.

[0004] In summary, the prior art cannot monitor the status of the fastener in real time, which is not conducive to obtaining the status of the fastener in real time. Summary of the invention

[0005] The present invention provides a fastener monitoring method, system, device and storage medium to solve the problem that the status of fasteners cannot be monitored in real time and is not conducive to real-time acquisition of the fastener status, so as to reduce the risk of equipment failure and improve the operating efficiency and safety of the equipment.

[0006] In a first aspect, in order to solve the above technical problems, the present invention provides a fastener monitoring method, which is executed by a data processing terminal and comprises: A sensor is installed on the fastener to obtain resistance data collected by the sensor; Performing a conversion operation according to the resistance data to obtain a real-time resistance value; Calculating according to the real-time resistance value to obtain the preload force; Making a judgment based on the preload force to obtain a state monitoring result of the fastener; Wherein, the fasteners include any one of bolts, screws or nuts or any combination of two; The sensor comprises an angle sensor for sensing the rotation of the fastener and outputting a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal.

[0007] In an optional implementation, performing a conversion operation according to the resistance data to obtain a real-time resistance value includes: The real-time resistance value is calculated by the following formula: ; ; Among them, V is the real-time resistance value, △R is the temperature compensation constant, and R is the normal resistance value when the sensor is working normally. is the standard value of resistance, is the maximum resistance value across the sensor, is the resistance value between the two poles on the sensor; The resistance data includes a normal resistance value, a maximum resistance value at both ends, a standard resistance value and a resistance value between two extreme points.

[0008] In an optional implementation manner, the calculating according to the real-time resistance value to obtain the preload force includes: The preload force is calculated by the following formula: ; ; Among them, F is the preload force of the bolt, V is the real-time resistance value, is the contact area of ​​the area to be installed, α is the thermal expansion coefficient of the material of the fastener, R is the normal resistance value of the sensor when it is working normally, t is the time, is the initial measured resistance value of the sensor, k is the slope of linear increase with increasing temperature, is the preset error coefficient.

[0009] In an optional implementation, the determining according to the preload force to obtain a state monitoring result of the fastener includes: When the preload force satisfies F≤A1 F max When the bolts of the fasteners fail to meet the tightening standard, the status monitoring result is output; When the preload force meets A1 F max <F≤A2 F max When , the output includes the status monitoring result that the bolts of the fasteners are not loosened to the point of being unusable; When the preload force meets A2 F max <F≤F max When , the status monitoring result of the bolts of the fasteners being loosened is output; Among them, A1 and A2 are preset constants. A1 is smaller than A2. max The preset maximum preload force.

[0010] In an optional implementation manner, the obtaining resistance data collected by the sensor includes: The functional relationship between the resistance data and the angle is: ; in, is the normal resistance value when the sensor is working normally, represents the first stable resistance value, represents the second stable resistance value, represents the current angle of the fastener, Indicates the maximum preload angle of the fastener. Indicates the loosening angle of the fastener; When the angle is When , the fastener is in the maximum preload state; When the angle Greater than When , the fastener is in a pre-tightened state; When the angle Less than The fastener is in a loose state.

[0011] In an optional implementation manner, the process of determining the standard resistance value includes: Obtain the initial resistance standard value and preload force range collected by the sensor; Draw a graph based on the initial resistance standard value and the preload range, with the initial resistance value as the horizontal coordinate and the preload range as the vertical coordinate, and draw a corresponding relationship diagram between the resistance value range and the preload range; The final standard resistance value is determined by calculating according to the corresponding relationship diagram between the resistance value range and the preload force range.

[0012] In an optional implementation manner, the process of determining the preload force range includes: Obtain the tightening force range of the fastener; Proper division is performed according to the tightening force range to obtain a plurality of tightening force sub-intervals; According to the multiple tightening force sub-intervals, the pre-tightening forces of all test points in the interval are taken to calculate the average pre-tightening force; The pre-tightening force ranges corresponding to the plurality of tightening force sub-intervals are determined according to the average pre-tightening force.

[0013] In a second aspect, the present invention provides a fastener monitoring system, comprising: A data acquisition module, used to acquire resistance data collected by the sensor; A data conversion module, used to perform a conversion operation according to the resistance data to obtain a real-time resistance value; A data calculation module, used to calculate according to the real-time resistance value to obtain a preload force; A state judgment module, used to make a judgment based on the preload force to obtain a state monitoring result of the fastener; Wherein, the fasteners include any one of bolts, screws or nuts or any combination of two; The sensor comprises an angle sensor for sensing the rotation of the fastener and outputting a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal.

[0014] In a third aspect, the present invention further provides an electronic device, comprising a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements any one of the above-mentioned fastener monitoring methods when executing the computer program.

[0015] In a fourth aspect, the present invention further provides a computer-readable storage medium, the computer-readable storage medium comprising a stored computer program, wherein when the computer program is running, the device where the computer-readable storage medium is located is controlled to execute any one of the above-mentioned fastener monitoring methods.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The present invention discloses a fastener monitoring method, which monitors the tightening force of the fastener in real time through a sensor installed on the fastener, and calculates the pre-tightening force according to the change of the real-time resistance value, so as to realize the real-time monitoring of the fastener state, including obtaining the resistance data collected by the sensor; performing conversion operation according to the resistance data to obtain the real-time resistance value; performing calculation according to the real-time resistance value to obtain the pre-tightening force; judging according to the pre-tightening force to obtain the state monitoring result of the fastener; realizing real-time monitoring, better reflecting the tightness state of the fastener, providing data support for maintenance, and improving maintenance efficiency. When the pre-tightening force exceeds the dangerous value, the system will send an alarm signal to promptly notify relevant personnel to handle it, further enhancing safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a schematic flow chart of a fastener monitoring method provided by a first embodiment of the present invention; Figure 2 is a schematic diagram of the structure of a fastener provided by an embodiment of the present invention; Figure 3 Schematic diagram of the structure of a fastener monitoring system provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] At present, in mechanical equipment, fasteners such as bolts, screws and screws are key components to ensure the stable operation of the equipment. As the use time increases, these fasteners may undergo plastic deformation, fatigue and wear due to high temperature, temperature difference, vibration, impact, corrosion, etc., which will reduce the preload of the fasteners, thereby affecting the safety performance and operation efficiency of the equipment. Therefore, it is necessary to regularly maintain or monitor the bolts, screws, screws, etc. of the equipment in order to understand the tightening status of these fasteners in real time.

[0020] In one prior art, the accuracy of fastener detection is poor due to sensor failure, which generally can only meet the requirements of regular equipment maintenance. In some equipment that needs to monitor the tightness of fasteners in real time, most of them still use regular disassembly and manual detection. However, the state of fasteners cannot be monitored in real time in the prior art, which is not conducive to obtaining the state of fasteners in real time.

[0021] To solve the above problems, refer to Figure 1 The first embodiment of the present invention provides a fastener monitoring method, comprising the following steps: S11, installing a sensor on the fastener to obtain resistance data collected by the sensor; S12, performing a conversion operation according to the resistance data to obtain a real-time resistance value; S13, performing calculation according to the real-time resistance value to obtain a preload force; S14, making a judgment based on the preload force to obtain a state monitoring result of the fastener; Wherein, the fasteners include any one of bolts, screws or nuts or any combination of two; The sensor comprises an angle sensor for sensing the rotation of the fastener and outputting a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal.

[0022] The present invention discloses a fastener monitoring method, which monitors the tightening force of the fastener in real time through a sensor installed on the fastener, and calculates the pre-tightening force according to the change of the real-time resistance value, so as to realize the real-time monitoring of the fastener state, including obtaining the resistance data collected by the sensor; performing conversion operation according to the resistance data to obtain the real-time resistance value; performing calculation according to the real-time resistance value to obtain the pre-tightening force; judging according to the pre-tightening force to obtain the state monitoring result of the fastener; realizing real-time monitoring, better reflecting the tightness state of the fastener, providing data support for maintenance, and improving maintenance efficiency. When the pre-tightening force exceeds the dangerous value, the system will send an alarm signal to promptly notify relevant personnel to handle it, further enhancing safety.

[0023] In step S11, it is necessary to obtain the resistance data collected by the sensor, install the sensor on the fastener, and according to the shell, one end of the shell is installed on the thread root of the fastener by a screw, and the shell is provided with a semicircular notch for matching with the fastener; a resistance wire is provided in the shell, and the two ends of the resistance wire are respectively connected to the positive and negative electrodes of the data processing terminal through wires; the change of the sensor resistance value is related to the preload on the fastener. The sensor includes a temperature sensor, an angle sensor or a resistance sensor, and the sensor is used to collect resistance data in real time.

[0024] It should be noted that a temperature sensor is a device that can sense temperature and convert it into a usable output signal. Its principle is mainly based on the phenomenon that different materials or components exhibit different physical properties as temperature changes. The resistance value of a thermistor changes with temperature, usually with a negative temperature coefficient (NTC), that is, the resistance decreases as temperature rises, or a positive temperature coefficient (PTC), that is, the resistance increases as temperature rises; RTD (resistance temperature detector) uses the property that the resistance of metal platinum changes with temperature to measure temperature; the temperature sensor is connected to a data acquisition module or microcontroller measurement device, a known excitation current is applied to the thermistor, and the voltage across it is measured; according to Ohm's law ( ) calculate the resistance value or apply a constant voltage to the thermistor and measure the current passing through it, and then calculate the resistance value according to Ohm's law. The most basic function of the temperature sensor is to measure temperature and convert temperature changes into electrical signals for monitoring and recording. Angle sensors are devices that can detect angle changes and are widely used in various automation and control systems. Angle sensors are installed on fasteners that need to be monitored. These sensors can be based on the Hall effect, magnetoresistive effect, or potentiometer-type sensors. The angle sensors are connected to the data acquisition system through appropriate circuits, and the analog resistance value of the sensor is read through the analog-to-digital converter (ADC) in the circuit and converted into digital signals; these digital signals represent the current angle or position of the fastener. Angle sensors provide key angle measurement data for various applications by converting mechanical rotation or linear movement into electrical signals, thereby improving the performance, stability and safety of the equipment. A resistance sensor is a detection device that can convert the change of the measured value into the change of the resistance parameter of the sensitive element, and convert it into the output of voltage or current signal through the circuit, so as to realize the measurement of non-electrical quantity. According to the monitoring requirements, a suitable resistance sensor type is selected, such as strain gauge, thermistor or piezoresistive, and the resistance sensor is installed on the fastener to be monitored to ensure that the sensor is in full contact with the monitored object. The sensor is connected to the data acquisition system through an appropriate circuit, which includes using an analog-to-digital converter (ADC) to read the analog resistance value of the sensor and convert it into a digital signal. Resistance sensors have been widely used in industrial automation, aerospace, medical equipment and other fields due to their high measurement accuracy, fast response speed and simple structure. The above includes an angle sensor, which is used to sense the rotation of the fastener and output a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal.

[0025] In one implementation, the functional relationship between the real-time resistance value data and the angle is: ; in, Indicates the real-time resistance value, represents the first stable resistance value, represents the second stable resistance value, represents the current angle of the fastener, Indicates the maximum preload angle of the fastener. Indicates the loosening angle of the fastener; Angle When the angle is greater than When the angle is less than When the fastener is in a loose state; Bolt rotation angle It can be expressed as, ; The pitch can be expressed as, ; Then we get, ; in, is the diameter of the bolt screw, is the thread pitch; Rotation angle of the nut It can be expressed as, ; The pitch can be expressed as, ; Then we get, ; in, is the actual tightening angle of the nut, is the diameter of the nut, is the thread pitch.

[0026] It should be noted that the first stable resistance value generally refers to a stable state of resistance value exhibited by the sensor under specific conditions, such as a specific temperature, pressure or load, and the second stable resistance value generally refers to another stable state of resistance value exhibited by the sensor under specific conditions, such as different temperatures, pressures or loads. These two values ​​can be used as reference points for the sensor in normal working conditions to obtain the first stable resistance value and the second stable resistance value, including: Measure under standard conditions: Place the sensor in a standard test environment, such as standard atmospheric pressure and room temperature, and measure and record its resistance value; Measuring under specific conditions: If the sensor is used in a specific application environment, such as high temperature or high pressure, the resistance value needs to be measured under these specific conditions; The first stable resistance value and the second stable resistance value can be used as an indication of the normal working state of the sensor, and can also be used to determine whether the sensor has a fault; The above includes calculating the angle, obtaining the real-time voltage value data output by the angle sensor, and calculating the real-time voltage value data according to a preset functional relationship to obtain the corresponding angle.

[0027] In step S12, a conversion operation is performed according to the resistance data to obtain a real-time resistance value.

[0028] In one implementation, the real-time resistance value is calculated by the following formula: ; ; Among them, V is the real-time resistance value, △R is the temperature compensation constant, and R is the normal resistance value when the sensor is working normally. is the standard value of resistance, is the maximum resistance value across the sensor, is the resistance value between the two poles of the sensor; The resistance data includes a normal resistance value, a maximum resistance value at both ends, a standard resistance value and a resistance value between two extreme points.

[0029] It should be noted that the process of converting the resistance data mentioned above to obtain the real-time resistance value includes: installing the resistance sensor on the fastener to be monitored, ensuring that the sensor is in full contact with the monitored object, connecting the sensor to the data acquisition system through an appropriate circuit, which includes using an analog-to-digital converter (ADC) to read the analog resistance value of the sensor and convert it into a digital signal, and reading the analog resistance value of the sensor through the ADC in the circuit and converting it into a digital signal to obtain the real-time resistance value. By real-time monitoring of the change in resistance value, it can be inferred whether the preload force of the fastener is within the set range, thereby ensuring the reliability and safety of the connection.

[0030] When using a thermistor for temperature detection, you can connect the thermistor in series with a known resistor through a voltage divider circuit, and then calculate the resistance of the thermistor by measuring the output voltage of the voltage divider. The formula is: ;in is the supply voltage, is the voltage across the thermistor, is the resistance of the thermistor, is the resistance value of a known resistor. The temperature compensation constant △R is a set of values ​​used to correct the performance changes of sensors or electronic devices at different temperatures. These constants can be linear or nonlinear and are used to compensate for measurement errors caused by temperature changes.

[0031] Under laboratory conditions, the performance of the sensor or device at different temperatures is tested, the relationship between its output and temperature is recorded, and the least square method or other statistical methods are used to fit the temperature compensation formula based on the experimental data, and the temperature compensation constant is extracted from it. Or according to the characteristics of the sensor or device, a mathematical model is established to describe its behavior at different temperatures, and the temperature compensation constant is derived. The temperature compensation constant helps to reduce the impact of temperature fluctuations on the stability of the measurement system and ensure that the system can work normally at different ambient temperatures. The maximum resistance value at both ends of the sensor It usually refers to the maximum resistance value that the sensor can reach under specific conditions. The maximum resistance value provides a known upper limit, which helps to calibrate the measurement system to ensure the accuracy of the measurement results. By monitoring whether the resistance value reaches or exceeds the maximum value, it can be determined whether the sensor or circuit is faulty and repair or replace it in time.

[0032] Among them, the resistance value between the two poles on the sensor Refers to the resistance value between the two output terminals of the sensor under specific conditions. This value can be obtained by direct measurement. By using the resistance measurement function of the multimeter, the two probes of the multimeter are respectively touched to the two poles of the sensor, and the resistance value displayed on the multimeter is read. Or the sensor is part of a circuit, and the voltage and current in the circuit can be measured using Ohm's law ( ) to calculate the resistance value.

[0033] Furthermore, the process of determining the standard value of resistance includes: Obtain the initial resistance standard value and preload force range collected by the sensor; Draw a graph based on the initial resistance standard value and the preload range, with the initial resistance value as the horizontal coordinate and the preload range as the vertical coordinate, and draw a corresponding relationship diagram between the resistance value range and the preload range; The final standard resistance value is determined by calculating according to the corresponding relationship diagram between the resistance value range and the preload force range.

[0034] It should be noted that the standard resistance value of the resistance sensor refers to the nominal resistance value of the resistance sensor under specific conditions. The above calculation process includes: Observe the data points of the corresponding relationship graph and observe whether the relationship graph has linear, quadratic or other non-linear relationships. Statistical software or graphical tools can be used to help identify trend lines; Based on the determined trend type, the equation of the trend line is calculated. The relationship is linear and the trend line equation may be ,in is the standard value of initial resistance, is the preload, and are the parameters of the equation; The final resistance standard value can be a specific point on the trend line, or the average of the initial resistance standard values ​​within the preload range. Here are a few common methods: Average value method: For each preload range, calculate the average value of all initial resistance standard values ​​in the range as the final resistance standard value; Median method: select the intersection of the trend line and the median of the preload range as the final resistance standard value; Regression analysis: Use linear regression or nonlinear regression analysis to determine the relationship between the initial standard resistance value and the preload force, and use the regression equation to calculate the final resistance standard value; The resistance standard value provides a known and accurate resistance value as a reference standard for calibrating and verifying other measuring equipment, thereby ensuring the measurement accuracy of the entire monitoring system and helping to maintain the stability of the monitoring system. Through regular calibration, the system can be ensured to operate stably in the long term and reduce errors.

[0035] The process of determining the preload range includes: Obtain the tightening force range of the fastener; Proper division is performed according to the tightening force range to obtain a plurality of tightening force sub-intervals; According to the multiple tightening force sub-intervals, the pre-tightening forces of all test points in the interval are taken to calculate the average pre-tightening force; The pre-tightening force ranges corresponding to the plurality of tightening force sub-intervals are determined according to the average pre-tightening force.

[0036] It should be noted that the tightening force range refers to the range of torque applied to achieve the required preload when tightening fasteners, such as bolts and screws. This range is usually determined based on the size, material, strength grade of the fastener and the characteristics of the connected material. The tightening force range of the fastener can be obtained by the following methods: The calculation is usually based on the material properties of the bolt, such as yield strength, the geometric dimensions of the thread: diameter and pitch, and the expected operating conditions of the threaded connection; The experimental method uses professional equipment such as torque wrenches and preload testers in the laboratory or on site to measure the tightening torque and the corresponding preload, thereby determining the range of the tightening force. The preload range refers to the range between the minimum and maximum values ​​of the preload applied during the tightening of fasteners, such as bolts, screws or nuts, in order to ensure the reliability and tightness of the connection. The preload range is crucial for ensuring the friction between the connecting parts, preventing loosening and leakage, and improving the overall rigidity and strength of the connection. The preload range can ensure that there is sufficient friction between the connecting parts to prevent relative sliding or loosening under the action of external force, thereby improving the reliability of the entire connection and ensuring that there is sufficient preload between the connecting parts, which can reduce the impact of vibration and impact on the connection and extend the service life of the connection. By setting the upper limit of the preload, damage or failure of the connecting parts due to excessive preload can be avoided.

[0037] In step S13, a calculation is performed based on the real-time resistance value to obtain the preload force.

[0038] In one implementation, the preload force is calculated using the following formula: ; ; Among them, F is the preload force of the bolt, V is the real-time resistance value, is the contact area of ​​the area to be installed, α is the thermal expansion coefficient of the material of the fastener, R is the normal resistance value of the sensor when it is working normally, t is the time, is the initial measured resistance value of the sensor, k is the slope of linear increase with increasing temperature, is a preset error coefficient, wherein the preset error coefficient Including 1.10, 1.15, 1.20 or 1.25.

[0039] It is worth noting that the preload force F of the bolt refers to the axial force pre-applied to the bolt in order to ensure the reliability and safety of the connection during the connection process. This force generates sufficient friction between the connected parts to prevent relative sliding or loosening under the action of external force, thereby ensuring the stability and reliability of the connection. A special force sensor measuring device can be used to directly measure the force exerted on the bolt during the tightening process or to calculate the preload force by measuring the elongation of the bolt during the tightening process using the elastic modulus of the material. The elongation of the bolt needs to be measured using an ultrasonic measuring device. The real-time resistance value determination process includes: installing the resistance sensor on the fastener to be monitored, ensuring that the sensor is in full contact with the monitored object, and connecting the sensor to the data acquisition system through an appropriate circuit, which includes using an analog-to-digital converter (ADC) to read the analog resistance value of the sensor and convert it into a digital signal. The analog resistance value of the sensor is read through the ADC in the circuit and converted into a digital signal to obtain the real-time resistance value.

[0040] Among them, the contact area of ​​the area to be installed , which refers to the contact area between the fastener and the connected part during the connection or assembly process. The contact area of ​​a circular fastener such as a bolt or screw can be obtained by calculating the area of ​​the circle. The formula is: ;in, is the diameter of the bolt. The thermal expansion coefficient α of the material of the above fastener refers to the ratio of the dimensional change per unit length or unit volume to the temperature change when the material changes in temperature. It is a physical parameter that reflects the change in the performance of solid materials when subjected to thermal shock, and is essential to ensure the performance of fasteners at different temperatures. The resistance value R of the above sensor when it is working normally refers to the resistance value of the sensor maintained within a stable range under specific conditions. This value is determined by the design and material properties of the sensor.

[0041] Specifically, the method for obtaining this resistance value generally includes: using a multimeter or ohmmeter to directly measure the resistance of the sensor, adjusting the multimeter to an appropriate resistance range, then disconnecting the sensor from the circuit, connecting the two probes of the multimeter to the two ends of the sensor, and reading the displayed resistance value or the resistance value of the sensor can be determined by measuring with a specific voltage divider circuit or bridge circuit. The above sensor initially measures the resistance value It refers to the resistance value of the sensor under specific conditions when it is not subjected to external effects such as force, heat, light, etc. This value is the reference resistance value of the sensor, and the resistance of the sensor can be directly measured using a multimeter or ohmmeter. Disconnect the sensor from the circuit, then connect the two probes of the multimeter to both ends of the sensor, and read the displayed resistance value. If the sensor needs to work in a specific circuit, you can use a standard circuit to measure its initial resistance value, or under laboratory conditions, by controlling environmental variables such as temperature and humidity, and using precise measuring equipment to determine the initial resistance value of the sensor. The slope k that increases linearly with increasing temperature usually refers to the material's resistance temperature coefficient, which describes the rate at which the resistance value changes with temperature. For thermistor-type sensors, their resistance value will change with temperature, and this slope is the parameter that describes this change. It can be measured by measuring the resistance value of the sensor at different temperatures under laboratory conditions and recording the data; using the least squares method or other statistical methods to fit the resistance-temperature characteristic curve based on the experimental data, and extracting the slope from it or building a standard circuit, such as a voltage divider circuit or a bridge circuit, to measure the resistance value of the sensor and record the data that changes with temperature; the slope value is obtained by calculating the ratio of the resistance change to the temperature change between different temperature points. For some metal materials, the resistance temperature coefficient is a positive value, indicating that the resistance increases with increasing temperature; for semiconductors or insulating materials, the resistance temperature coefficient may be a negative value, indicating that the resistance decreases with increasing temperature. Preset error coefficient It usually refers to a coefficient introduced to compensate or correct systematic errors, random errors, etc. during measurement or data processing. It is used to indicate the degree of deviation between the measured value and the true value. It is an important parameter for evaluating measurement accuracy. The error coefficient can be a fixed value or a dynamic value that changes with conditions. Including 1.10, 1.15, 1.20 or 1.25, it can provide an accuracy assessment of the measurement results, help determine the credibility of the measurement results, and be used to compensate for the errors of the measurement results to improve the accuracy of the measurement. During the production and manufacturing process, the error coefficient can be used for quality control to ensure that the product meets the specification requirements.

[0042] In step S14, a judgment is made based on the preload force to obtain the status monitoring result of the fastener: When the preload force satisfies F≤A1 F max When the bolts of the fasteners fail to meet the tightening standard, the status monitoring result is output; When the preload force meets A1 F max <F≤A2 F max When , the output includes the status monitoring result that the bolts of the fasteners are not loosened to the point of being unusable; When the preload force meets A2 F max <F≤F max When , the status monitoring result of the bolts of the fasteners being loosened is output; Among them, A1 and A2 are preset constants. A1 is smaller than A2. max is the preset maximum preload force; The preset constant A1 includes 0.85 and 0.80, and the preset constant A2 includes 0.90 and 0.95.

[0043] It is worth noting that the maximum preload refers to the maximum value of the force applied in advance during the connection process in order to enhance the reliability and tightness of the connection and prevent gaps or relative slippage between the connecting parts after being loaded. It can provide friction resistance, increase contact surface pressure, and prevent loosening, thereby improving the strength and reliability of the connection. The maximum preload can be obtained by the following methods, including: Tensile method: Calculates preload by measuring bolt elongation, which involves measuring the length of the unloaded bolt, loading the bolt and causing it to deform elastically, and then measuring its change in length; Torque method: Use a wrench to apply torque to the bolt or nut to generate the required tightening load. This tightening load is the preload. The friction coefficient between the two contact surfaces can be calculated through torque or tensile testing to determine the preload. Software simulation: Use ABAQUS software to simulate bolt preload through temperature method, penetration contact method or bolt load method; The maximum preload can improve the reliability, anti-loosening ability and fatigue strength of the bolt connection, enhance the tightness and rigidity of the connection, increase the contact surface pressure between the bolt and the base material, make the connection tighter, help share the load and improve the strength of the connection, prevent the bolt from loosening under vibration or load, and ensure that the connection remains stable. The preset constants A1 and A2 can help calibrate the sensor to ensure that its output signal is consistent with the actual measurement value, thereby achieving standardization of the measurement, and can also accurately adjust the output of the sensor to reduce errors and improve the overall measurement accuracy.

[0044] The following describes the working process of the present invention using a common scenario as an example. Figure 2 , which is Figure 1 Schematic diagram of the working scenario of the method.

[0045] Miniaturized, highly sensitive resistance sensors are installed on aircraft fasteners to collect real-time data on resistance changes in the fasteners. The collected analog signals are converted into digital signals via an analog-to-digital converter (ADC) for analysis by the data processing terminal. The digital signals are transmitted to the data processing terminal, where the resistance value data is processed using advanced algorithms to calculate the preload force of the fasteners. The preload force is compared with a preset safety threshold to determine whether the fastener is in a normal state, an alarm state, or a dangerous state.

[0046] In summary, the present invention discloses a fastener monitoring method, which monitors the tightening force of the fastener in real time through a sensor installed on the fastener, and calculates the pre-tightening force according to the change of the real-time resistance value, thereby realizing real-time monitoring of the fastener state, including obtaining the resistance data collected by the sensor; performing conversion operations according to the resistance data to obtain the real-time resistance value; performing calculations according to the real-time resistance value to obtain the pre-tightening force; making judgments according to the pre-tightening force to obtain the state monitoring result of the fastener; realizing real-time monitoring, better reflecting the tightness state of the fastener, providing data support for maintenance, and improving maintenance efficiency. When the pre-tightening force exceeds the dangerous value, the system will send an alarm signal to promptly notify relevant personnel to handle it, further enhancing safety.

[0047] Reference Figure 3 A second embodiment of the present invention provides a fastener monitoring system, comprising: A data acquisition module, used to acquire resistance data collected by the sensor; A data conversion module, used to perform a conversion operation according to the resistance data to obtain a real-time resistance value; A data calculation module, used to calculate according to the real-time resistance value to obtain a preload force; The state judgment module is used to make a judgment based on the preload force to obtain a state monitoring result of the fastener.

[0048] Wherein, the fasteners include any one of bolts, screws or nuts or any combination of two; The sensor includes an angle sensor for sensing the rotation of the fastener and outputting a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal; Preferably, the data acquisition module includes: The sensor acquisition unit is used to obtain the resistance data collected by the sensor: It is necessary to obtain resistance data collected by sensors, and install sensors on fasteners, including temperature sensors, angle sensors or resistance sensors, and the sensors are used to collect resistance data in real time; The functional relationship between real-time resistance value data and angle is: ; in, Indicates the real-time resistance value, represents the first stable resistance value, represents the second stable resistance value, represents the current angle of the fastener, Indicates the maximum preload angle of the fastener. Indicates the loosening angle of the fastener; Angle When the angle is greater than When the angle is less than When the fastener is in a loose state; Bolt rotation angle It can be expressed as, ; The pitch can be expressed as, ; Then we get, ; in, is the diameter of the bolt screw, is the thread pitch; Rotation angle of the nut It can be expressed as, ; The pitch can be expressed as, ; Then we get, ; in, is the actual tightening angle of the nut, is the diameter of the nut, is the thread pitch.

[0049] Preferably, the data conversion module includes: The real-time resistance value calculation unit is used to calculate the real-time resistance value by the following formula: ; ; Among them, V is the real-time resistance value, △R is the temperature compensation constant, and R is the normal resistance value when the sensor is working normally. is the standard value of resistance, is the maximum resistance value across the sensor, is the resistance value between the two poles on the sensor; The resistance data includes a normal resistance value, a maximum resistance value at both ends, a standard resistance value and a resistance value between two extreme points; The process of determining the standard value of the resistance includes: Obtain the initial resistance standard value and preload force range collected by the sensor; Draw a graph based on the initial resistance standard value and the preload range, with the initial resistance value as the horizontal coordinate and the preload range as the vertical coordinate, and draw a corresponding relationship diagram between the resistance value range and the preload range; Calculate according to the corresponding relationship diagram between the resistance value range and the preload force range to determine the final resistance standard value; The process of determining the preload force range includes: Obtain the tightening force range of the fastener; Proper division is performed according to the tightening force range to obtain a plurality of tightening force sub-intervals; According to the multiple tightening force sub-intervals, the pre-tightening forces of all test points in the interval are taken to calculate the average pre-tightening force; The pre-tightening force ranges corresponding to the plurality of tightening force sub-intervals are determined according to the average pre-tightening force.

[0050] Preferably, the data calculation module includes: The preload calculation unit is used to calculate the preload by the following formula: ; ; Among them, F is the preload force of the bolt, V is the real-time resistance value, is the contact area of ​​the area to be installed, α is the thermal expansion coefficient of the material of the fastener, R is the normal resistance value of the sensor when it is working normally, t is the time, is the initial measured resistance value of the sensor, k is the slope of linear increase with increasing temperature, is a preset error coefficient, wherein the preset error coefficient Including 1.10, 1.15, 1.20 or 1.25.

[0051] Preferably, the state judgment module includes: The fastener condition monitoring unit is used to determine the fastener condition results by the following methods: When the preload force satisfies F≤A1 F max When the bolts of the fasteners fail to meet the tightening standard, the status monitoring result is output; When the preload force meets A1 F max <F≤A2 F max When , the output includes the status monitoring result that the bolts of the fasteners are not loosened to the point of being unusable; When the preload force meets A2 F max <F≤F max When , the status monitoring result of the bolts of the fasteners being loosened is output; Among them, A1 and A2 are preset constants. A1 is smaller than A2. max For the preset maximum preload force, the preset constant A1 includes 0.85 and 0.80, and the preset constant A2 includes 0.90 and 0.95.

[0052] In summary, the present invention discloses a fastener monitoring system, which monitors the tightening force of the fastener in real time through a sensor installed on the fastener, and calculates the pre-tightening force according to the change of the real-time resistance value, thereby realizing real-time monitoring of the fastener state, including obtaining the resistance data collected by the sensor; performing conversion operations according to the resistance data to obtain the real-time resistance value; performing calculations according to the real-time resistance value to obtain the pre-tightening force; making judgments according to the pre-tightening force to obtain the state monitoring result of the fastener; realizing real-time monitoring, better reflecting the tightness state of the fastener, providing data support for maintenance, and improving maintenance efficiency. When the pre-tightening force exceeds the dangerous value, the system will send an alarm signal to promptly notify relevant personnel to handle it, further enhancing safety.

[0053] It should be noted that a fastener monitoring system provided in an embodiment of the present invention is used to execute all process steps of a fastener monitoring method in the above embodiment, and the working principles and beneficial effects of the two correspond one to one, so they will not be described in detail.

[0054] The embodiment of the present invention further provides an electronic device. The electronic device includes: a processor, a memory, and a computer program stored in the memory and executable on the processor, such as a data processing terminal program. When the processor executes the computer program, the steps in the above-mentioned fastener monitoring method embodiments are implemented, such as Figure 1 Alternatively, when the processor executes the computer program, the functions of the modules / units in the above-mentioned device embodiments are realized, such as the data conversion module.

[0055] Exemplarily, the computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to implement the present invention. The one or more modules / units may be a series of computer program instruction segments capable of implementing specific functions, which are used to describe the execution process of the computer program in the electronic device.

[0056] The electronic device may be a computing device such as a desktop computer, a notebook, a PDA, and a smart tablet. The electronic device may include, but is not limited to, a processor and a memory. Those skilled in the art will appreciate that the above components are merely examples of electronic devices and do not constitute a limitation on the electronic device. The electronic device may include more or fewer components than the above components, or a combination of certain components, or different components. For example, the electronic device may also include input and output devices, network access devices, buses, etc.

[0057] The processor may be a central processing unit (CPU), other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor, etc. The processor is the control center of the electronic device, and uses various interfaces and lines to connect various parts of the entire electronic device.

[0058] The memory can be used to store the computer program and / or module, and the processor realizes various functions of the electronic device by running or executing the computer program and / or module stored in the memory, and calling the data stored in the memory. The memory can mainly include a program storage area and a data storage area, wherein the program storage area can store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area can store data created according to the use of the mobile phone (such as audio data, a phone book, etc.), etc. In addition, the memory can include a high-speed random access memory, and can also include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other volatile solid-state storage devices.

[0059] Wherein, if the module / unit integrated in the electronic device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the present invention implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. Wherein, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0060] It should be noted that the device embodiments described above are merely schematic, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. In addition, in the accompanying drawings of the device embodiments provided by the present invention, the connection relationship between the modules indicates that there is a communication connection between them, which may be specifically implemented as one or more communication buses or signal lines. A person of ordinary skill in the art may understand and implement it without paying any creative effort.

[0061] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A fastener monitoring method, characterized in that: Executed by the data processing terminal, including: A sensor is installed on the fastener to obtain resistance data collected by the sensor; Performing a conversion operation according to the resistance data to obtain a real-time resistance value; Calculating according to the real-time resistance value to obtain the preload force; Making a judgment based on the preload force to obtain a state monitoring result of the fastener; Wherein, the fasteners include any one of bolts, screws or nuts or any combination of two; The sensor comprises an angle sensor for sensing the rotation of the fastener and outputting a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal.

2. The fastener monitoring method according to claim 1, characterized in that: The converting operation is performed according to the resistance data to obtain a real-time resistance value, including: The real-time resistance value is calculated by the following formula: ； ； Among them, V is the real-time resistance value, △R is the temperature compensation constant, and R is the normal resistance value when the sensor is working normally. is the standard value of resistance, is the maximum resistance value across the sensor, is the resistance value between the two poles on the sensor; The resistance data includes a normal resistance value, a maximum resistance value at both ends, a standard resistance value and a resistance value between two extreme points.

3. The fastener monitoring method according to claim 2, characterized in that: The calculating according to the real-time resistance value to obtain the preload force includes: The preload force is calculated by the following formula: ； ； Among them, F is the preload force of the bolt, V is the real-time resistance value, is the contact area of ​​the area to be installed, α is the thermal expansion coefficient of the material of the fastener, R is the normal resistance value of the sensor when it is working normally, t is the time, is the initial measured resistance value of the sensor, k is the slope of linear increase with increasing temperature, is the preset error coefficient.

4. The fastener monitoring method according to claim 3, characterized in that: The determining according to the preload force to obtain the state monitoring result of the fastener includes: When the preload force satisfies F≤A1 F max When the bolts of the fasteners fail to meet the tightening standard, the status monitoring result is output; When the preload force meets A1 F max <F≤A2 F max When , the output includes the status monitoring result that the bolts of the fasteners are not loosened to the point of being unusable; When the preload force meets A2 F max <F≤F max When , the status monitoring result of the bolts of the fasteners being loosened is output; Among them, A1 and A2 are preset constants. A1 is smaller than A2. max The preset maximum preload force.

5. The fastener monitoring method according to claim 1, characterized in that: The step of obtaining the resistance data collected by the sensor includes: The functional relationship between the resistance data and the angle is: ； in, is the normal resistance value when the sensor is working normally, represents the first stable resistance value, represents the second stable resistance value, represents the current angle of the fastener, Indicates the maximum preload angle of the fastener. Indicates the loosening angle of the fastener; When the angle is When , the fastener is in the state of maximum preload; When the angle Greater than When , the fastener is in a pre-tightened state; When the angle Less than The fastener is in a loose state.

6. The fastener monitoring method according to claim 2, characterized in that: The process of determining the standard value of the resistance includes: Obtain the initial resistance standard value and preload force range collected by the sensor; Draw a graph based on the initial resistance standard value and the preload range, with the initial resistance value as the horizontal coordinate and the preload range as the vertical coordinate, and draw a corresponding relationship diagram between the resistance value range and the preload range; The final standard resistance value is determined by calculating according to the corresponding relationship diagram between the resistance value range and the preload force range.

7. The fastener monitoring method according to claim 6, characterized in that: The process of determining the preload force range includes: Obtain the tightening force range of the fastener; Proper division is performed according to the tightening force range to obtain a plurality of tightening force sub-intervals; According to the multiple tightening force sub-intervals, the pre-tightening forces of all test points in the interval are taken to calculate the average pre-tightening force; The pre-tightening force ranges corresponding to the plurality of tightening force sub-intervals are determined according to the average pre-tightening force.

8. A fastener monitoring system, characterized in that: Configured in the data processing terminal, including: A data acquisition module, used to acquire resistance data collected by the sensor; A data conversion module, used to perform a conversion operation according to the resistance data to obtain a real-time resistance value; A data calculation module, used to calculate according to the real-time resistance value to obtain a preload force; A state judgment module, used to make a judgment based on the preload force to obtain a state monitoring result of the fastener; Wherein, the fasteners include any one of bolts, screws or nuts or any combination of two; The sensor comprises an angle sensor for sensing the rotation of the fastener and outputting a voltage value signal according to the angle of rotation of the fastener, and the resistance data is a voltage value signal.

9. An electronic device, characterized in that: The invention comprises a processor, a memory, and a computer program stored in the memory and configured to be executed by the processor, wherein the processor implements the fastener monitoring method according to any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium includes a stored computer program, wherein when the computer program is executed, the device where the computer-readable storage medium is located is controlled to execute the fastener monitoring method according to any one of claims 1 to 7.

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