A nut loosening monitoring sensor for monitoring nut connection state in real time

Abstract

The utility model discloses a nut loosening monitoring sensor for real -time monitoring nut connection state relates to industrial equipment monitoring technical field, including the casing, be provided with chip circuit board in the casing, install radio frequency antenna, loosening trigger unit interface, battery interface on the chip circuit board, the casing includes upper cover and lower cover, and the upper cover and lower cover are mutually buckled and fixedly connected, be provided with alarm lamp window and extension interface on the upper cover, be provided with loosening trigger unit and battery on the lower cover, and loosening trigger unit is connected with loosening trigger unit interface, and battery is connected with battery interface. Advantageous effect lies in: the sensor adopts the non -invasive design of buckle or screw thread interface and is rotated into the upper portion of nut, avoids the reformation to nut and equipment, improves the installation efficiency by more than 50%. Taking large -scale bridge nut monitoring as an example, can be quickly deployed under the condition of not interrupting bridge operation, reduces installation cost and technical threshold, makes the sensor applicable to more complex scene.

Description

Technical Field

[0001] This utility model relates to the field of industrial equipment monitoring technology, and in particular to a nut loosening monitoring sensor for real-time monitoring of the nut connection status. Background Technology

[0002] In industrial equipment operation, traditional nut connections are prone to loosening due to vibration, alternating loads, and other factors, leading to equipment failure or even safety accidents. For example, loose nuts on wind turbine towers can cause collapse. Furthermore, manual inspection is costly, lacks real-time early warning capabilities, and some parts are difficult to maintain and have limited lifespan. Existing monitoring solutions rely on inefficient manual visual inspection, contact monitoring is prone to nut wear, wireless transmission consumes a lot of power, resulting in short battery life, vibration analysis is susceptible to interference leading to insufficient accuracy, and closed hardware interfaces and software protocols result in poor equipment scalability. Utility Model Content

[0003] The purpose of this invention is to provide a nut loosening monitoring sensor for real-time monitoring of the nut connection status in order to solve the above-mentioned problems.

[0004] This utility model achieves the above objectives through the following technical solutions:

[0005] A nut loosening monitoring sensor for real-time monitoring of nut connection status includes a housing, a chip circuit board inside the housing, an RF antenna, a loosening trigger unit interface, and a battery interface mounted on the chip circuit board, the housing including an upper cover and a lower cover, the upper cover and the lower cover being interlocked and fixedly connected, the upper cover having an alarm light window and an expansion interface, the lower cover having a loosening trigger unit and a battery, the loosening trigger unit being connected to the loosening trigger unit interface, and the battery being connected to the battery interface.

[0006] Preferably, the top and bottom covers are made of aluminum alloy.

[0007] Preferably, the battery is a high-capacity lithium polymer battery.

[0008] Preferably, the battery interface is a reverse connection resistant interface.

[0009] Preferably, the frequency band of the radio frequency antenna is M.

[0010] Preferably, the expansion interface adopts the UART interface standard.

[0011] The beneficial effects are:

[0012] 1. This sensor employs a non-invasive design, using a snap-fit ​​or threaded interface to screw into the upper part of the nut. This avoids modifications to the nut and equipment, increasing installation efficiency by over 50%. Taking the monitoring of nuts on large bridges as an example, it can be quickly deployed without interrupting bridge operation, reducing installation costs and technical barriers, and making the sensor applicable to more complex scenarios.

[0013] 2. This sensor integrates triaxial angle, temperature, and vibration signals for multi-dimensional analysis. Through data fusion algorithms and cross-validation, the accuracy of nut loosening detection is improved to over 99%. It can provide accurate early warnings of minor loosening, allowing sufficient time for equipment maintenance, preventing safety accidents caused by loose nuts, and ensuring production continuity and safety.

[0014] 3. This sensor uses a low-power chip and a 433MHz RF module, combined with dynamic sampling frequency technology, reducing power consumption by 80% compared to Bluetooth solutions. The theoretical battery life is up to 3 years, reducing maintenance frequency. Simultaneously, the hardware reserves standardized interfaces, and the software adopts open protocols, supporting various external devices and integration with enterprise management systems. This meets the functional expansion needs of different scenarios and effectively solves the problem of insufficient adaptability of existing equipment.

[0015] The additional technical features and advantages of this utility model will become more apparent from the following description, or may be learned through specific practice of this utility model. Attached Figure Description

[0016] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the following detailed description to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0017] Figure 1 This is a schematic diagram of the structure of a nut loosening monitoring sensor for real-time monitoring of nut connection status as described in this utility model;

[0018] Figure 2 This is a top view of a nut loosening monitoring sensor for real-time monitoring of nut connection status, as described in this utility model.

[0019] Figure 3 This is a schematic diagram of the working principle of a nut loosening monitoring sensor for real-time monitoring of nut connection status, as described in this utility model.

[0020] The following are the labels in the attached diagram: 1. Top cover; 2. Alarm light window; 3. Expansion interface; 4. Chip circuit board; 5. Radio frequency antenna; 6. Loose trigger unit interface; 7. Battery interface; 8. Bottom cover; 9. Loose trigger unit; 10. Battery. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0022] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0023] The present invention will be further described below with reference to the accompanying drawings:

[0024] like Figures 1-3 As shown, a nut loosening monitoring sensor for real-time monitoring of nut connection status includes a housing. Inside the housing is a chip circuit board 4, which is the core processing hub of the entire sensor. The chip circuit board 4 employs a multi-layer board design to optimize circuit layout and reduce signal interference. The chip circuit board 4 is equipped with a radio frequency antenna 5, a loosening trigger unit interface 6, and a battery interface 7. The radio frequency antenna 5 operates in the 433MHz frequency band, which offers advantages such as strong diffraction capability and excellent anti-interference performance in industrial environments. The radio frequency antenna 5 is connected to the chip circuit board 4 via a dedicated radio frequency connector to ensure stable and efficient signal transmission, transmitting monitoring data wirelessly as radio frequency signals.

[0025] The housing includes an upper cover 1 and a lower cover 8, which are interlocked and fixedly connected. The upper cover 1 has an alarm light window 2 and an expansion interface 3. The alarm light window 2 provides visual alarm, alerting maintenance personnel with a flashing light when the nut becomes loose. The expansion interface 3 uses a standardized design, such as the common UART interface standard, supporting various external devices, such as accelerometers, to enhance monitoring capabilities in specific scenarios. The lower cover 8 houses a loosening trigger unit 9 and a battery 10. The loosening trigger unit interface 6 connects to the loosening trigger unit 9, which is based on advanced MEMS technology. The loosening trigger unit 9, through a special mechanical structure design, can tightly fit the nut, sensing the minute displacements or vibrations caused by loosening in real time. It accurately converts these physical changes into electrical signals, transmitting them to the chip circuit board 4 for further processing. The loosening trigger unit 9 uses MEMS (Micro-Electro-Mechanical Systems) technology to monitor nut loosening. The loosening trigger unit 9 internally consists of a micromechanical structure and sensitive elements, using a carefully designed mechanical structure, such as an elastic cantilever beam or micro-spring, to achieve a tight fit with the nut. When the nut loosens, the resulting minute vibrations or displacements cause deformation of the micromechanical structure, which in turn leads to changes in the electrical parameters of the sensitive element, such as changes in capacitance and resistance, ultimately converting the physical signal into an electrical signal that can be processed by the chip circuit board 4.

[0026] Battery 10 is connected to battery interface 7, providing stable power to the entire sensor. Battery interface 7 is a reverse-connection protected interface to prevent damage to the circuit due to incorrect battery installation. Battery 10 is a high-capacity lithium polymer battery with advantages such as high energy density and low self-discharge rate. Battery 10 is connected to chip circuit board 4 through a power management system. The power management system uses a dedicated power management chip that can intelligently adjust the charging and discharging current to ensure efficient utilization and long lifespan of battery 10. It also supports sleep / wake-up mode, allowing automatic wake-up for data acquisition. During sleep mode, system power consumption is extremely low, significantly extending battery 10's runtime.

[0027] Both the upper cover 1 and the lower cover 8 are made of aluminum alloy. Utilizing the excellent mechanical properties of aluminum alloy, such as high strength, vibration resistance, and excellent corrosion resistance, it provides reliable physical protection for internal components. The lower cover 8 is tightly sealed to the upper cover 1 via threads or snap-fit, forming a sealed space that effectively resists harsh external environmental factors, such as dust, moisture, and corrosive gases, from corroding the internal circuitry. Furthermore, in scenarios with extremely low equipment maintenance requirements and where replacing the battery 10 is extremely difficult, such as nut monitoring in deep-sea equipment or buried facilities, the battery 10 can be a disposable lithium-ion battery. Lithium-ion batteries have extremely high energy density and an ultra-long shelf life, eliminating the need to replace the battery 10 throughout the entire lifespan of the equipment. However, attention must be paid to its discharge characteristics to ensure compatibility with the equipment's power management system. Additionally, appropriate overvoltage and overcurrent protection circuits must be included to prevent damage to the equipment from abnormal discharge of the battery 10.

[0028] The sensor includes an information acquisition module, a data acquisition module, a power supply module, and a communication module.

[0029] The information acquisition module includes a three-axis angle module, a temperature acquisition module, and a loosening trigger unit 9.

[0030] The information acquisition module uses a high-precision MEMS triaxial accelerometer or gyroscope as the core sensing element, enabling real-time and accurate monitoring of the nut's angular changes along the X, Y, and Z axes. When the nut loosens, its spatial position and orientation change, resulting in angular displacement. The triaxial angle module achieves sub-millimeter accuracy; for example, it can detect minute angular changes of 0.1° along a specific axis. Through real-time acquisition and analysis of these angular change data, a corresponding signal is triggered when the angular displacement exceeds a preset threshold, providing crucial information for determining nut looseness.

[0031] The temperature acquisition module assists in determining whether a nut is loose, employing a high-precision thermistor or thermocouple as the temperature sensing element. When a nut is loose, the friction between the nut and bolt intensifies, leading to a localized temperature increase. The temperature acquisition module monitors temperature changes around the nut in real time and transmits the temperature data to the chip circuit board 4. By comparing and analyzing the temperature data with that under normal operating conditions, and by cross-validating the data from the triaxial angle module and the loosening trigger unit 9, the false alarm rate can be effectively reduced. For example, if the nut temperature rises by more than 5°C in a short period of time, accompanied by abnormal changes in the triaxial angle and a signal from the loosening trigger unit 9, it can be more reliably determined that the nut has become loose.

[0032] The loosening trigger unit 9, based on MEMS (Micro-Electro-Mechanical Systems) technology, is extremely sensitive to the displacement caused when the nut loosens. When the nut loosens, the resulting vibration or displacement causes deformation of the micromechanical structure inside the loosening trigger unit 9, leading to changes in the electrical parameters of the sensitive element, thereby converting the physical signal into an electrical signal. These electrical signals are rapidly transmitted to the chip circuit board 4 as key raw data for determining whether the nut is loose.

[0033] The data acquisition module includes an integrated microcontroller, which uses a low-power ARM core chip as its core processor. This chip boasts powerful computing capabilities and rich peripheral interfaces. During the nut loosening monitoring process, it is primarily responsible for processing various electrical signals transmitted from the information acquisition module. First, the built-in analog-to-digital converter (ADC) performs high-precision digitization of the analog signal. Then, the on-chip digital signal processing (DSP) unit filters the digitized signal to remove noise interference, such as using a Butterworth low-pass filter to effectively filter out high-frequency noise. Next, the signal is amplified to increase its strength for subsequent feature extraction and analysis. In the feature extraction stage, the Fast Fourier Transform (FFT) algorithm is used to convert the time-domain signal into a frequency-domain signal, extracting characteristic frequency information related to nut loosening. Simultaneously, a built-in threshold comparison algorithm, trained based on extensive experimental data and machine learning algorithms, can accurately determine the degree of nut loosening in real time, classifying the loosening state into three levels: slight, moderate, and severe.

[0034] The threshold comparison algorithm is one of the core algorithms of the data acquisition module. Based on a large amount of experimental data and real-world nut loosening cases, it has undergone repeated testing and optimization to pre-set loosening thresholds for different types of nuts and application scenarios. These thresholds cover multiple dimensions, including angle change thresholds, temperature change thresholds, and vibration frequency thresholds. During actual operation, the algorithm compares and analyzes the collected real-time data with the preset thresholds. Simultaneously, machine learning technology is introduced to continuously learn and update historical and real-time data, automatically adapting to changes in different environments and working conditions. This effectively distinguishes interference signals such as environmental vibrations from genuine nut loosening signals, greatly improving the accuracy and reliability of nut loosening judgment.

[0035] The power supply module includes a power management system, which uses a dedicated power management chip and features intelligent charge / discharge management, sleep / wake-up control, and power status monitoring. During charging, it intelligently adjusts the charging current and voltage based on the battery type and charge status, employing a constant current-constant voltage charging mode to ensure safe and rapid charging of the battery while preventing overcharging and damage. During discharging, it monitors the battery voltage and current in real time. When the battery charge falls below a set threshold, it automatically switches to a low-power mode to further reduce system power consumption and extend battery life. In sleep / wake-up mode, the system automatically wakes up at preset time intervals, such as every 10 minutes, to collect and process data before quickly entering sleep mode. The entire process consumes very little power, theoretically allowing the battery to last up to 3 years, significantly reducing equipment maintenance frequency and costs.

[0036] The communication module includes a 433MHz radio frequency (RF) module. This module is responsible for modulating the nut loosening data processed by the data acquisition module into an RF signal, which is then wirelessly transmitted through a matched high-gain omnidirectional antenna. The 433MHz band has excellent propagation characteristics in industrial environments, with strong diffraction capabilities, effectively penetrating obstacles of a certain thickness, such as walls and metal structures, reducing signal attenuation during transmission. Simultaneously, it exhibits excellent anti-interference performance, enabling stable operation in complex electromagnetic environments. The RF module modulates the data according to specific communication protocols, such as the commonly used ASK (Amplitude Shift Keying) or FSK (Frequency Shift Keying) modulation methods, loading the digital signal onto the 433MHz carrier signal, which is then radiated into the surrounding space through the omnidirectional antenna. In unobstructed open environments, the transmission distance can reach 50 meters, meeting the data transmission needs of most industrial monitoring sites. Furthermore, compared to communication methods such as Bluetooth and Wi-Fi, the 433MHz RF module has lower power consumption, making it more suitable for battery-powered, low-power monitoring devices. Additionally, in scenarios with extremely high transmission distance requirements and relatively small data transmission volumes, such as wind farms in remote mountainous areas or large bridge monitoring, LoRa (LongRange) communication technology can be selected. LoRa has ultra-long-distance transmission capabilities and low power consumption. In this case, the parameters of the RF antenna 5, such as the antenna's resonant frequency and gain, need to be adjusted according to the LoRa communication frequency band and signal characteristics to adapt to the signal transmission requirements of the LoRa communication module.

[0037] When installing the sensor, record its unique ID number and clearly define its installation location. This installation location information has been pre-entered into the handheld device. Use the handheld device to bind the sensor's unique ID number to the installation location. Apply thread-locking adhesive to the anchor rod where the sensor will be installed. Screw the sensor onto the top of the nut being monitored, ensuring it is close to the nut. Screw the sensor in slowly. Once the top light illuminates, adjust the screw pitch accordingly, rotating it back approximately 60 degrees. Observe the top light. If it stops flashing, the installation is complete. If it continues to flash, unscrew the sensor to within 10mm of the nut being monitored, then slowly screw the sensor in again. Once the top light illuminates, adjust the screw pitch accordingly, rotating it back approximately 60 degrees. Repeat this process.

[0038] In summary, traditional contact sensors require damaging the original structure of the nut during installation, making installation complex and prone to damage. This sensor uses a non-invasive design with a snap-fit ​​or threaded interface that screws into the top of the nut, avoiding modifications to the nut and equipment, and improving installation efficiency by over 50%. Taking the monitoring of nuts on large bridges as an example, it can be quickly deployed without interrupting bridge operation, reducing installation costs and technical barriers, making the sensor applicable to more complex scenarios. Previously, single-parameter monitoring was susceptible to environmental interference and had low accuracy. This sensor integrates three-axis angle, temperature, and vibration signals for multi-dimensional analysis, and through data fusion algorithms and cross-validation, improves the accuracy of nut loosening detection to over 99%. It can provide accurate early warnings of minor loosening, buying sufficient time for equipment maintenance, avoiding safety accidents caused by nut loosening, and ensuring production continuity and safety. Traditional monitoring equipment suffers from high power consumption and poor scalability. This sensor uses a low-power chip and a 433MHz RF module, combined with dynamic sampling frequency technology, reducing power consumption by 80% compared to Bluetooth solutions, with a theoretical battery life of up to 3 years, reducing maintenance frequency. Meanwhile, the hardware reserves standardized interfaces, and the software adopts open protocols, supporting the connection of various external devices and integration with enterprise management systems, meeting the functional expansion needs of different scenarios, and effectively solving the problem of insufficient adaptability of existing devices.

[0039] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model.

Claims

1. A nut loosening monitoring sensor for real-time monitoring of nut connection status, characterized in that: The device includes a housing, inside which is a chip circuit board (4). The chip circuit board (4) is equipped with a radio frequency antenna (5), a loosening trigger unit interface (6), and a battery interface (7). The housing includes an upper cover (1) and a lower cover (8). The upper cover (1) and the lower cover (8) are interlocked and fixedly connected. The upper cover (1) is provided with an alarm light window (2) and an expansion interface (3). The lower cover (8) is provided with a loosening trigger unit (9) and a battery (10). The loosening trigger unit (9) is connected to the loosening trigger unit interface (6), and the battery (10) is connected to the battery interface (7).

2. A nut loosening monitoring sensor for real-time monitoring of nut connection status according to claim 1, characterized in that: The upper cover (1) and the lower cover (8) are made of aluminum alloy.

3. A nut loosening monitoring sensor for real-time monitoring of nut connection status according to claim 1, characterized in that: The battery (10) is a high-capacity lithium polymer battery.

4. A nut loosening monitoring sensor for real-time monitoring of nut connection status according to claim 1, characterized in that: The battery interface (7) is a reverse connection resistant interface.

5. A nut loosening monitoring sensor for real-time monitoring of nut connection status according to claim 1, characterized in that: The frequency band of the radio frequency antenna (5) is 433M.

6. A nut loosening monitoring sensor for real-time monitoring of nut connection status according to claim 1, characterized in that: The expansion interface (3) adopts the UART interface standard.

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