Power transmission iron tower inhaul cable looseness detection device and nondestructive detection method

Abstract

The invention provides a power transmission iron tower inhaul cable looseness detection device and a nondestructive detection method, and belongs to the technical field of power transmission system maintenance. The detection device comprises a mechanical vibration excitation device, a piezoelectric vibration sensor, a resistance strain type tension sensor, a signal acquisition module, a signal processing unit and a power supply control module. The mechanical vibration excitation device is arranged on the inhaul cable of the power transmission iron tower and installed near the anchoring end of the inhaul cable or at the position of a middle fixing node, and is used for generating mechanical vibration and applying the mechanical vibration to the inhaul cable. The piezoelectric vibration sensor and the resistance strain type tension sensor are arranged on the inhaul cable, are close to the mechanical vibration excitation device and are used for detecting vibration signals and stress signals caused by the vibration signals; the signal acquisition module is used for simultaneously receiving a vibration signal and a stress signal; the signal processing unit analyzes and processes the received signals so as to judge the loosening state of the inhaul cable. According to the invention, under the condition that reliable vibration of the inhaul cable is realized, dual-signal acquisition of the inhaul cable is realized, and the detection accuracy is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power transmission system maintenance, and in particular to a power transmission tower cable loosening detection device and a non-destructive detection method. Background Art

[0002] In the power transmission system, the cables of the transmission tower are used to maintain the overall stability and structural safety of the transmission tower. Due to long-term exposure to complex natural environments, the cables are often affected by factors such as wind, rain, and temperature changes, which can cause the pre-tension of the cables to decrease or become loose. The loosening of the cables not only reduces the overall stiffness of the tower, but may also cause structural deformation, increasing the potential risks of the transmission system. Therefore, timely and effective detection of the loose state of the cables is an important part of ensuring the safety of the transmission line.

[0003] At present, traditional cable loosening detection mainly relies on manual inspection or simple mechanical vibration test. Although the manual inspection method is intuitive, it has high operating risks and is limited by the subjective experience of the inspectors, which is prone to misjudgment or missed detection. When using a simple mechanical vibration device for detection, usually only vibration signals can be collected, but due to the single signal and lack of real-time monitoring of the cable tension, it is difficult to accurately judge the loose state of the cable. Summary of the invention

[0004] The present application provides a transmission tower cable loosening detection device and a non-destructive detection method, which are used to solve the problem that the prior art only relies on single signal detection and cannot accurately determine the loose state of the cable.

[0005] In a first aspect, the present application provides a transmission tower cable loosening detection device, including a mechanical vibration excitation device, a piezoelectric vibration sensor, a resistive strain type tension sensor, a signal acquisition module, a signal processing unit and a power control module;

[0006] The mechanical vibration excitation device is arranged on the cable of the transmission tower and installed near the anchor end or at the middle fixed node of the cable of the transmission tower, and is used to generate mechanical vibration and apply it to the cable to cause vibration and tension change of the cable;

[0007] The piezoelectric vibration sensor is arranged on the cable and close to the mechanical vibration excitation device, and is used to detect the vibration signal caused by the mechanical vibration excitation device;

[0008] The resistance strain type tension sensor is arranged on the cable and close to the mechanical vibration excitation device, and is used to detect the stress signal generated by the cable during vibration;

[0009] The signal acquisition module is connected to the piezoelectric vibration sensor and the resistive strain tension sensor respectively through cables, and is used to simultaneously receive the vibration signal and the stress signal;

[0010] The signal processing unit is connected to the signal acquisition module via a cable, and is used to analyze and process the received signal to determine the loose state of the cable;

[0011] The power control module is connected to the mechanical vibration excitation device, the signal acquisition module and the signal processing unit respectively through cables to provide the required power support.

[0012] Further optionally, the piezoelectric vibration sensor and the resistive strain type tension sensor are both arranged on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device, so as to synchronously detect the vibration and tension signals caused by the mechanical vibration excitation device;

[0013] The vicinity of the anchor end is within a range of no more than 30-50 cm from the anchor point where the cable is fixed on the iron tower or the foundation structure; the intermediate fixed node is the position of the support or reinforcement structure along the length direction of the cable or a position no more than 20-30 cm away from it.

[0014] Further optionally, the signal acquisition module includes a vibration signal receiving module, a stress signal receiving module and a signal preprocessing module; the vibration signal receiving module is connected to the piezoelectric vibration sensor through a cable, and is used to receive the vibration signal and perform preliminary filtering, and the output end of the vibration signal receiving module is connected to the signal preprocessing module; the stress signal receiving module is connected to the resistive strain type tension sensor through a cable, and is used to receive the stress signal and perform preliminary filtering, and the output end of the stress signal receiving module is connected to the signal preprocessing module; the signal preprocessing module is used to merge the received signals and transmit them to the signal processing unit, and the output end of the signal preprocessing module is connected to the signal processing unit through a cable.

[0015] Further optionally, the signal processing unit includes a signal amplification module, a filtering module, an analog-to-digital conversion module and a signal feature extraction module; the signal amplification module is used to amplify the received vibration signal and stress signal to improve the signal processing accuracy, the input end of the signal amplification module is connected to the output end of the signal acquisition module through a cable, and is used to amplify the received vibration signal and stress signal, and its output end is connected to the filtering module; the filtering module is connected to the output end of the signal amplification module, and is used to remove noise and extract signals within the target frequency range, and the output end of the filtering module is connected to the analog-to-digital conversion module; the analog-to-digital conversion module is connected to the output end of the filtering module, and is used to convert the filtered analog signal into a digital signal, and the output end of the analog-to-digital conversion module is connected to the signal feature extraction module; the signal feature extraction module is used to analyze the amplified, filtered and digitized signals to determine the loose state of the cable, the input end of the signal feature extraction module is connected to the analog-to-digital conversion module, and its output end is used to output the processing result.

[0016] Further optionally, the power control module includes a power input interface, a power output interface, a voltage regulating unit, a PWM controller and a power management unit; the power input interface is used to receive external power input and is electrically connected to the voltage regulating unit; the voltage regulating unit is connected to the PWM controller, used to adjust the input voltage and provide a stable voltage to the PWM controller; the PWM controller is connected to the power management unit, used to adjust the pulse frequency and width of the output current, and transmit the adjusted current to the power output interface; the power management unit is connected to the power output interface, used to monitor and protect the output current, and provide current stabilization and overcurrent protection functions; the power output interface is connected to the mechanical vibration excitation device, the signal acquisition module and the signal processing unit respectively through cables, and is used to provide stable power output to each module.

[0017] Further optionally, the mechanical vibration excitation device includes a shell, a drive motor, an excitation hammer head and a guide mechanism; the drive motor is a linear motor, fixedly mounted at the rear end inside the shell, and used to drive the excitation hammer head to perform reciprocating linear motion, the output shaft of the drive motor is connected to the rear end of the excitation hammer head through a coupling, and the shell is a square shell; the excitation hammer head is a cylindrical steel structure, the front end of the excitation hammer head is provided with an arc-shaped groove, the front end of the excitation hammer head faces the opening opened at the front end of the shell, and the excitation hammer head can generate reciprocating impact motion under the electric drive of the drive motor; the guide mechanism includes a guide sleeve fixed to the front end of the shell, and the guide sleeve is slidably matched with the excitation hammer head.

[0018] Further optionally, the guide mechanism also includes a spring, which is arranged at the rear of the excitation hammer head, and a fixing ring located at the rear section of the excitation hammer head is fixedly sleeved on the excitation hammer head, the front end of the spring is connected to the rear end of the guide sleeve, and the rear end of the spring is connected to the fixing ring, and the spring is located between the guide sleeve and the fixing ring and is in a pre-compression state; when the excitation hammer head moves forward driven by the drive motor, the spring can be further compressed to store elastic potential energy; when the excitation hammer head completes the impact and is released, the elastic force of the spring can cause the excitation hammer head to return quickly.

[0019] Further optionally, the mechanical vibration excitation device is connected to a connecting base, a vertically arranged square through hole is provided at one end of the connecting base, the mechanical vibration excitation device distributed vertically to the connecting base is passed through the square through hole, the shell has an open end passed through the square through hole and is connected to the connecting base through a locking bolt, the connecting base is provided with a slide groove arranged along the vertical height direction on the inner wall of the square through hole, the shell is provided with a boss that slides with the slide groove, the connecting base is also provided with screw holes distributed up and down on the outer wall of the square through hole, and the locking bolts are respectively provided in the screw holes; three C-shaped elastic clamps with openings are fixedly provided at the bottom end of the connecting base at evenly spaced intervals along the length direction, the connecting base is connected to the cable through the three C-shaped elastic clamps, and a non-slip lining is pasted on the inner side of the C-shaped elastic clamp.

[0020] Further optionally, the transmission tower cable loosening detection device of the present application further includes a clamping assembly for mounting the piezoelectric vibration sensor or the resistive strain tension sensor, and the clamping assembly includes:

[0021] A cylindrical body, with a sensor mounting portion at the bottom for accommodating and fixing the sensor;

[0022] Two U-shaped clamps are respectively arranged on both sides of the cylindrical body, and two clamps loaded with torsion springs to provide elastic clamping force are arranged on the inner side of each U-shaped clamp; a non-slip lining is pasted on the surface of the clamp; a baffle is hinged on one side of the bottom end of the U-shaped clamp, and a threaded connection hole for connecting a tightening bolt is provided on the other side of the bottom end of the U-shaped clamp, and a connecting through hole that matches the threaded connection hole and can be passed through by the tightening bolt is provided on the baffle. After the U-shaped clamp is locked and connected to the baffle by the tightening bolt, the cable in the U-shaped clamp is locked and fixed.

[0023] On the other hand, the present application also provides a method for nondestructive detection of loose power transmission tower cables, which uses the above-mentioned power transmission tower cable loose detection device of the present application, including the following steps:

[0024] Step 1: The mechanical vibration excitation device is fixedly installed near the anchor end or at the middle fixed node of the transmission tower cable, and the driving power is provided to the mechanical vibration excitation device through the power control module, so that the mechanical vibration excitation device can generate mechanical vibration and apply the vibration to the cable;

[0025] Step 2: Install a piezoelectric vibration sensor and a resistive strain tension sensor on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device to detect vibration signals and stress signals respectively;

[0026] Step 3: Start the mechanical vibration excitation device to generate impact vibration and apply it to the cable, inducing vibration and tension change of the cable;

[0027] Step 4: The vibration signal collected by the piezoelectric vibration sensor and the stress signal collected by the resistance strain type tension sensor are synchronously received and transmitted through the signal acquisition module, and the signal acquisition module performs preliminary processing on the signal and transmits it to the signal processing unit;

[0028] Step 5: In the signal processing unit, the received vibration signal and stress signal are analyzed and processed to determine the loose state of the cable.

[0029] Compared with the prior art, this application has the following beneficial effects:

[0030] 1. The transmission tower cable loosening detection device of the present application is a detection device including a mechanical vibration excitation device, a piezoelectric vibration sensor and a resistive strain tension sensor. It can realize dual signal collection of the cable while realizing reliable vibration of the cable. The piezoelectric vibration sensor can capture the vibration signal caused by the vibration applied by the mechanical vibration excitation device, and the resistive strain tension sensor can be used to detect the stress signal of the cable in real time. Such a structural design can synchronously obtain the dynamic vibration information and tension change of the cable, effectively overcoming the error caused by relying only on a single signal in the traditional method, thereby significantly improving the accuracy of detection.

[0031] 2. The signal acquisition module of the present application is connected to the piezoelectric vibration sensor and the resistive strain tension sensor through cables respectively, and receives two signals at the same time. The signal processing unit is connected to the signal acquisition module through cables to realize the transmission and analysis of the collected signals. This design not only ensures the stability of the transmission connection, but also can better ensure the integrity of data transmission, improve the overall performance of the detection device, and enable efficient transmission and processing of signals in the field environment; by using the signal processing unit, the collected vibration and stress signals can be analyzed and processed, and the use of multi-signal processing methods can facilitate comprehensive judgment of whether the cable is loose or in other abnormal conditions, thereby more accurately reflecting the true state of the cable and reducing the probability of misjudgment or missed judgment during the detection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 A system configuration diagram of a transmission tower cable loosening detection device provided in one embodiment of the present application;

[0034] Figure 2 A system configuration diagram of a signal acquisition module provided in one embodiment of the present application;

[0035] Figure 3 A system configuration diagram of a signal processing unit provided in one embodiment of the present application;

[0036] Figure 4 A system configuration diagram of a power control module provided in one embodiment of the present application;

[0037] Figure 5 A schematic diagram of the connection between the mechanical vibration excitation device and the connection base provided in one embodiment of the present application;

[0038] Figure 6 A schematic diagram of the structure of a mechanical vibration excitation device provided in one embodiment of the present application;

[0039] Figure 7 An internal schematic diagram of a mechanical vibration excitation device provided in one embodiment of the present application;

[0040] Figure 8 A schematic diagram of the structure of a connection base provided in one embodiment of the present application;

[0041] Fig. 9A schematic diagram of installing a piezoelectric vibration sensor in a clamping assembly provided in an embodiment of the present application;

[0042] Fig.10 A schematic diagram of installing a resistive strain gauge tension sensor in a clamping assembly provided in an embodiment of the present application.

[0043] In the figure, 10, mechanical vibration excitation device; 11, shell; 111, boss; 12, drive motor; 13, excitation hammer; 131, arc groove; 14, guide mechanism; 141, guide sleeve; 142, spring; 143, fixing ring; 20, piezoelectric vibration sensor; 30, resistance strain type tension sensor; 40, signal acquisition module; 41, vibration signal receiving module; 42, stress signal receiving module; 43, signal preprocessing module; 50, signal processing unit; 51, signal amplification module; 52, filtering module; 53, analog-to-digital conversion module; 54 , signal feature extraction module; 60, power control module; 61, power input interface; 62, power output interface; 63, voltage regulation unit; 64, PWM controller; 65, power management unit; 70, connecting base; 71, square through hole; 711, slide groove; 72, locking bolt; 73, C-type elastic clamp; 80, clamping assembly; 81, cylindrical body; 811, sensor mounting part; 82, U-shaped clamp; 821, torsion spring; 822, splint; 823, baffle; 8231, connecting through hole; 824, tightening bolt; 825, threaded connection hole. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present application.

[0045] like Figure 1-Figure 10 As shown, the transmission tower cable loosening detection device of the embodiment of the present application includes a mechanical vibration excitation device 10, a piezoelectric vibration sensor 20, a resistive strain tension sensor 30, a signal acquisition module 40, a signal processing unit 50 and a power control module 60.

[0046] A mechanical vibration excitation device 10 is provided on the cable of the transmission tower and installed near the anchor end or at an intermediate fixed node of the cable of the transmission tower, and is used to generate mechanical vibration and apply it to the cable to cause vibration and tension change of the cable;

[0047] A piezoelectric vibration sensor 20 is disposed on the cable and close to the mechanical vibration excitation device 10, and is used to detect a vibration signal caused by the mechanical vibration excitation device 10;

[0048] The resistance strain type tension sensor 30 is arranged on the cable and close to the mechanical vibration excitation device 10, and is used to detect the stress signal generated by the cable during the vibration process;

[0049] The signal acquisition module 40 is connected to the piezoelectric vibration sensor 20 and the resistive strain tension sensor 30 through cables, respectively, for simultaneously receiving the vibration signal and the stress signal;

[0050] The signal processing unit 50 is connected to the signal acquisition module 40 via a cable, and is used to analyze and process the received signal to determine the loose state of the cable;

[0051] The power control module 60 is respectively connected to the mechanical vibration excitation device 10, the signal acquisition module 40 and the signal processing unit 50 through cables to provide the required power support.

[0052] The transmission tower cable loosening detection device of the embodiment of the present application is a detection device including a mechanical vibration excitation device 10, a piezoelectric vibration sensor 20 and a resistive strain type tension sensor 30. It can realize dual signal collection of the cable while realizing reliable vibration of the cable. The piezoelectric vibration sensor 20 can capture the vibration signal caused by the vibration applied by the mechanical vibration excitation device 10, and the resistive strain type tension sensor 30 can be used to detect the stress signal of the cable in real time. This structural design can synchronously obtain the dynamic vibration information and tension change of the cable, effectively overcoming the error caused by relying only on a single signal in the traditional method, thereby significantly improving the accuracy of detection.

[0053] The signal acquisition module 40 of the embodiment of the present application is connected to the piezoelectric vibration sensor 20 and the resistive strain tension sensor 30 respectively through cables, and receives two signals at the same time. The signal processing unit 50 is connected to the signal acquisition module 40 through cables to realize the transmission and analysis of the collected signals. This design not only ensures the stability of the transmission connection, but also can better ensure the integrity of data transmission, improve the overall performance of the detection device, and enable efficient transmission and processing of signals in the field environment; by using the signal processing unit 50, the collected vibration and stress signals can be analyzed and processed, and the use of multi-signal processing can facilitate comprehensive judgment of whether the cable is loose or in other abnormal conditions, thereby being able to more accurately reflect the true state of the cable and reduce the probability of misjudgment or missed judgment during the detection process.

[0054] In this embodiment, the sensor selected for detecting the vibration signal caused by the mechanical vibration excitation device 10 is a piezoelectric vibration sensor 20, which is determined based on the application scenario and detection requirements.

[0055] The piezoelectric vibration sensor 20 is specifically used to measure vibration amplitude and frequency. This type of sensor mainly detects vibration intensity and spectrum to evaluate the operating status of the structure or equipment. The piezoelectric vibration sensor 20 uses the piezoelectric effect to convert mechanical vibration into an electrical signal output. Its measurement focuses more on measuring vibration rather than acceleration. The piezoelectric vibration sensor 20 usually outputs a signal proportional to the vibration amplitude. The piezoelectric vibration sensor 20 is suitable for detecting the overall vibration state of cables, bridges and large structures to evaluate looseness or structural health. The embodiment of the present application uses a piezoelectric vibration sensor 20 to detect the overall vibration state of the cable to reflect tension changes and looseness. In this embodiment, the resistance strain tension sensor 30 is used to detect the stress signal generated by the cable during vibration. The principle of the resistance strain tension sensor 30 is based on strain detection of a resistance strain gauge adhered to an elastic body. When the cable applies force, the deformation of the elastic body causes the resistance of the strain gauge to change, thereby detecting tension. Moreover, the cost of the resistance strain tension sensor 30 is relatively low, which can reduce the manufacturing cost of the detection device.

[0056] Furthermore, in some embodiments, the piezoelectric vibration sensor 20 and the resistive strain type tension sensor 30 are both arranged on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device 10, so as to synchronously detect the vibration and tension signals caused by the mechanical vibration excitation device 10. This method helps to ensure that the signals collected by the two sensors have high correlation, reduces the signal attenuation and time delay problems caused by the large distance between the sensor and the excitation source, and therefore, the accuracy of signal collection can be improved, making the detection results more reliable.

[0057] The vicinity of the anchor end is within 30-50 cm from the anchor point where the cable is fixed on the tower or foundation structure; the intermediate fixed node is the location of the support or reinforcement structure along the length of the cable or a location no more than 20-30 cm away from it.

[0058] The anchoring end is within a range of no more than 30-50cm from the anchoring point where the cable is fixed on the tower or foundation structure. It is a position where the cable is subjected to relatively concentrated force, which affects the tension and vibration characteristics of the entire cable and is suitable for tension and vibration detection. The position of the support or reinforcement structure of the intermediate fixed node along the length direction of the cable or no more than 20-30cm away from it provides a flexible arrangement within the full length of the cable, so that the installation stability of the detection device and the effectiveness of signal transmission can be improved to better meet the needs of different tower structures. The two sensors, the piezoelectric vibration sensor 20 and the resistive strain tension sensor 30, are arranged near the mechanical vibration excitation device 10, which helps to collect vibration signals and stress signals at the same time. This arrangement method can not only realize real-time monitoring of cable vibration, but also obtain its stress state. By synchronously detecting vibration and stress data, it can provide more comprehensive cable loosening state information and support more accurate analysis and judgment. This multi-dimensional data acquisition method helps to improve the early recognition ability of the detection device for cable loosening, and improves the efficiency and safety of prevention and maintenance work.

[0059] Optionally, the signal acquisition module 40 includes a vibration signal receiving module 41, a stress signal receiving module 42 and a signal preprocessing module 43; the vibration signal receiving module 41 is connected to the piezoelectric vibration sensor 20 via a cable, for receiving the vibration signal and performing preliminary filtering, and the output end of the vibration signal receiving module 41 is connected to the signal preprocessing module 43; the stress signal receiving module 42 is connected to the resistive strain type tension sensor 30 via a cable, for receiving the stress signal and performing preliminary filtering, and the output end of the stress signal receiving module 42 is connected to the signal preprocessing module 43; the signal preprocessing module 43 is used to merge the received signals and transmit them to the signal processing unit 50, and the output end of the signal preprocessing module 43 is connected to the signal processing unit 50 via a cable.

[0060] In this embodiment, the signal acquisition module 40 includes a vibration signal receiving module 41, a stress signal receiving module 42 and a signal preprocessing module 43. By performing preliminary filtering on the vibration signal and the stress signal respectively, the environmental noise and interference signal can be effectively removed, the purity of the signal reception can be ensured, and the signal can be preprocessed at the initial stage of acquisition, so as to improve the signal processing precision and accuracy of the detection device. The signal preprocessing module 43 is used to merge the received vibration signal and stress signal and transmit them to the signal processing unit 50, so as to reduce the processing delay between each signal module, ensure the real-time and consistency of data transmission, and effectively integrate the signal through the signal preprocessing module 43, so as to realize the synchronous analysis of vibration and stress signals, thereby improving the overall integrity and analysis efficiency of the detection data, and meeting the requirements of rapid response. The vibration signal receiving module 41 is connected to the piezoelectric vibration sensor 20 through a cable, and the stress signal receiving module 42 is connected to the resistance strain type tension sensor 30 through a cable. Through such a cable connection relationship, the wiring structure between each sensor and the corresponding signal acquisition module is optimized, and the preliminary filtering and signal preprocessing are completed inside the signal acquisition module, which can reduce the influence of external interference on signal transmission.

[0061] In the signal acquisition module 40, the purpose of preliminary filtering is to remove gross interference and noise in the collected signal, which helps to have a basic signal-to-noise ratio when the signal is transmitted to the signal processing unit 50, so as to perform subsequent processing more efficiently. In the signal acquisition module 40, a simple low-pass filter can be used to remove high-frequency noise or a band-pass filter can be used to retain useful signals within a specific frequency band.

[0062] Optionally, the signal processing unit 50 includes a signal amplification module 51, a filtering module 52, an analog-to-digital conversion module 53 and a signal feature extraction module 54; the signal amplification module 51 is used to amplify the received vibration signal and stress signal to improve the signal processing accuracy, the input end of the signal amplification module 51 is connected to the output end of the signal acquisition module 40 through a cable, and is used to amplify the received vibration signal and stress signal, and its output end is connected to the filtering module 52; the filtering module 52 is connected to the output end of the signal amplification module 51, and is used to remove noise and extract signals within the target frequency range, and the output end of the filtering module 52 is connected to the analog-to-digital conversion module 53; the analog-to-digital conversion module 53 is connected to the output end of the filtering module 52, and is used to convert the filtered analog signal into a digital signal, and the output end of the analog-to-digital conversion module 53 is connected to the signal feature extraction module 54; the signal feature extraction module 54 is used to analyze the amplified, filtered and digitized signals to determine the loose state of the cable, the input end of the signal feature extraction module 54 is connected to the analog-to-digital conversion module 53, and its output end is used to output the processing result.

[0063] The signal processing unit 50 of this embodiment adopts a combination including a signal amplification module 51, a filtering module 52, an analog-to-digital conversion module 53 and a signal feature extraction module 54, so that the signal processing process is more complete. The signal amplification module 51 can amplify the received vibration signal and stress signal, so that the weak signal can be enhanced, and the signal processing accuracy is improved. The amplified signal passes through the filtering module 52, which can further remove noise and retain the signal within the target frequency range, thereby reducing the probability of false detection and missed detection, so as to enhance the accuracy and stability of signal analysis. In the signal processing unit 50, in order to perform more accurate filtering processing, a digital filter (such as FIR or IIR filter) can be used to remove interference of a specific frequency. The analog-to-digital conversion module 53 is responsible for converting the analog signal after amplification and filtering into a digital signal. The analog-to-digital conversion module 53 converts the signal from analog form to digital format, which can facilitate subsequent digital processing and analysis. The digital signal is easier to perform accurate analysis and processing, and can be stored and transmitted without distortion, so that the detection device can achieve more complex data analysis to improve the accuracy and repeatability of cable loosening detection. The signal feature extraction module 54 can be used to conduct in-depth analysis on the amplified, filtered and digitized signals to determine the loose state of the cable. Through the signal feature extraction module 54, key parameters of frequency, amplitude and waveform characteristics can be extracted and comprehensively analyzed to quickly identify the loose or damaged state of the cable.

[0064] Optionally, the power control module 60 includes a power input interface 61, a power output interface 62, a voltage regulating unit 63, a PWM controller 64 and a power management unit 65; the power input interface 61 is used to receive external power input and is electrically connected to the voltage regulating unit 63; the voltage regulating unit 63 is connected to the PWM controller 64, and is used to adjust the input voltage and provide a stable voltage to the PWM controller 64; the PWM controller 64 is connected to the power management unit 65, and is used to adjust the pulse frequency and width of the output current, and transmit the adjusted current to the power output interface 62; the power management unit 65 is connected to the power output interface 62, and is used to monitor and protect the output current, and provide current stabilization and overcurrent protection functions; the power output interface 62 is connected to the mechanical vibration excitation device 10, the signal acquisition module 40 and the signal processing unit 50 through cables, respectively, and is used to provide stable power output to each module.

[0065] In this embodiment, the power control module 60 includes a power input interface 61, a power output interface 62, a voltage regulating unit 63, a PWM controller 64 and a power management unit 65. By setting the voltage regulating unit 63, the input voltage can be adjusted so that the output voltage is stabilized within the required range, so that continuous and stable power can be provided in a complex field environment, thereby ensuring that key device components such as the mechanical vibration excitation device 10, the signal acquisition module 40 and the signal processing unit 50 are always in the best working state to ensure the stable use of the detection device. The power input interface 61 is used to connect an external power source, such as a rechargeable battery or a field power interface, to provide a stable power supply for the device. The design of the power input interface 61 needs to comply with the power input specification to ensure that there will be no problem of excessive voltage or current fluctuations when the power supply is connected. The power output interface 62 can be connected to the power-consuming part of the detection device through a cable to provide stable power.

[0066] The PWM controller 64 in the power control module 60, i.e., a pulse width modulation (PWM) controller, can be used to adjust the pulse frequency and width of the output current to control the impact frequency and strength of the mechanical vibration excitation device 10. When such an adjustment function is realized, the excitation intensity can be flexibly adjusted according to the characteristics of the cable, such as material, diameter and pre-tension, so that the impact effect of the mechanical vibration excitation device 10 on the cable is more accurate, avoiding detection errors caused by excessive or insufficient impact, and by optimizing the excitation frequency and strength, the adaptive detection of different types of cables can be achieved, thereby improving the applicability and reliability of the detection device. The power management unit 65 has the functions of current stabilization and overcurrent protection, so that it can respond in time when the current is abnormal (such as overcurrent, short circuit) to prevent damage to key components. This protection mechanism can not only effectively extend the service life of the mechanical vibration excitation device 10, the signal acquisition module 40 and the signal processing unit 50, but also improve the safety of the operation of the device, making it suitable for stable operation in a high-risk transmission tower environment.

[0067] In specific applications, the power source of the piezoelectric vibration sensor 20 and the resistive strain type tension sensor 30 can be realized according to the actual situation. For example, the piezoelectric vibration sensor 20 and the resistive strain type tension sensor 30 can be powered by the power control module 60, and both sensors can be connected to the power control module 60 through a cable, and the power control module 60 provides a stable power supply so that the sensor can operate stably when working. In addition, it can also be implemented by using a built-in battery power supply. When in use, the sensor can be powered by a small rechargeable battery, which can reduce the dependence on external cables and improve the flexibility of installation.

[0068] In some embodiments, the mechanical vibration excitation device 10 includes a housing 11, a drive motor 12, an excitation hammer 13 and a guide mechanism 14; the drive motor 12 is a linear motor, fixedly mounted at the rear end of the housing 11, and used to drive the excitation hammer 13 to perform reciprocating linear motion, the output shaft of the drive motor 12 is connected to the rear end of the excitation hammer 13 through a coupling, and the housing 11 is a square housing; the excitation hammer 13 is a cylindrical steel structure, and an arc groove 131 is provided at the front end of the excitation hammer 13, and the front end of the excitation hammer 13 faces the opening opened at the front end of the housing 11, and the excitation hammer 13 can generate reciprocating impact motion under the electric drive of the drive motor 12. Although the linear motor itself can provide linear motion, the guide mechanism 14 still helps to maintain the smooth and linear motion of the excitation hammer 13 and prevent lateral deviation, especially in the environment of outdoor transmission towers with complex use environments.

[0069] The guide mechanism 14 includes a guide sleeve 141 fixed to the front end of the housing 11, and the guide sleeve 141 is slidably matched with the excitation hammer 13. The guide mechanism 14 can reduce the load of the linear motor and reduce the instability factors caused by external interference during the movement of the excitation hammer 13, thereby extending the service life of the equipment. In addition, the guide mechanism 14 can help fix and align the excitation hammer 13 so that the excitation hammer 13 maintains correct contact with the detected cable.

[0070] The specific size of the mechanical vibration excitation device 10 can be designed according to the actual application and detection requirements. In this embodiment, in order to facilitate installation on the transmission tower cable and ensure sufficient excitation effect, its overall size is designed to be compact and portable. In this embodiment, the optional dimensions of the shell 11 are: length: 15-25cm, width: 5-10cm, height: 5-10cm. Such a size can provide sufficient excitation force and is convenient for technicians to carry and install in the tower cable or other limited space. The specific size needs to be adjusted according to the actual vibration intensity and the bearing capacity of the cable structure to ensure the detection effect and safety.

[0071] The mechanical vibration excitation device 10 provided in this embodiment adopts a structural design including a housing 11, a drive motor 12, an excitation hammer 13 and a guide mechanism 14, which can improve the stability and impact accuracy of the mechanical vibration excitation device 10, and can also improve the transmission efficiency and adaptability of the impact effect. Among them, the drive motor 12 adopts a linear motor, which is fixed in the housing 11 and connected to the rear end of the excitation hammer 13 through a coupling. The linear motor has the characteristics of high precision and fast response, can directly generate linear motion, and can achieve reciprocating motion through the control of current. In the detection of transmission tower cables, environmental conditions are usually more complex, such as vibration, wind load or other external interference. Therefore, the guide mechanism 14 must have a certain stability and buffering function to ensure the accuracy of the mechanical vibration excitation device 10 during impact and return.

[0072] In this embodiment, the linear motor can ensure the stable reciprocating motion of the excitation hammer 13 along a specific direction, effectively reduce the lateral deviation during the motion process, and maintain the impact accuracy. The addition of the shell 11 structure can effectively protect the drive motor 12 and the excitation hammer 13, prevent them from being affected by the outside world in harsh environments, and further improve the overall stability of the excitation device. Moreover, the excitation hammer 13 is designed as a cylindrical structure with an arc-shaped groove at the front end, which facilitates the hammer head to achieve a closer contact with the surface of the cable, thereby improving the vibration energy transmission efficiency during the impact process. In addition, the design of the arc-shaped groove can better adapt to the curvature of the cable, make the excitation process more uniform, and avoid energy loss and signal distortion caused by poor contact. This structural configuration enables the excitation hammer 13 to achieve effective mechanical impact on the surface of the cable.

[0073] In addition, the guide mechanism 14 design adopted by the mechanical vibration excitation device 10 of this embodiment can realize the precise guidance of the excitation hammer 13 and ensure the stable movement of the excitation hammer 13. The guide mechanism 14 in this embodiment includes a guide sleeve 141 fixed in the housing 11 and slidingly cooperates with the excitation hammer 13. Such a design provides precise linear motion guidance for the excitation hammer 13, so that it always maintains a stable motion trajectory when driven by the drive motor 12, effectively reduces the lateral swing in the impact movement, and also helps to extend the service life of the drive motor 12.

[0074] In some embodiments, the guide mechanism 14 also includes a spring 142, which is arranged behind the excitation hammer 13, and a fixing ring 143 located at the rear section of the excitation hammer 13 is fixedly sleeved on the excitation hammer 13, and the front end of the spring 142 is connected to the rear end of the guide sleeve 141, and the rear end of the spring 142 is connected to the fixing ring 143, and the spring 142 is located between the guide sleeve and the fixing ring 143 and is in a pre-compression state; when the excitation hammer 13 moves forward under the drive of the drive motor 12, the spring 142 can be further compressed to store elastic potential energy; when the excitation hammer 13 completes the impact and releases, the elastic force of the spring 142 can prompt the excitation hammer 13 to return quickly. In the detection of the transmission tower cable, if there is a large environmental disturbance, the addition of the spring 142 to the guide mechanism 14 can provide an additional buffering effect, absorb the impact force, and make the movement smoother. Furthermore, if there is a significant external force in the detection environment or frequent and stable reciprocating motion is required, and in order to avoid possible external influences on the linear motor during rapid resetting, it is very necessary to additionally provide the guide mechanism 14 with a spring 142 .

[0075] This embodiment adopts a guide mechanism 14 that can further increase the spring 142, which can improve the rebound speed and impact frequency of the excitation hammer 13. The guide mechanism 14 of this embodiment also includes a spring 142 arranged behind the excitation hammer 13. The spring 142 is pre-compressed and installed between the guide sleeve 141 and the fixing ring 143 at the rear end of the excitation hammer 13. Such a structural design enables the excitation hammer 13 to further compress the spring 142 during impact and store more elastic potential energy. When the excitation hammer 13 is released, the spring 142 rebounds quickly and pushes the excitation hammer 13 to quickly return to the initial position, thereby improving the rebound speed of the excitation hammer 13. Through the auxiliary effect of the spring 142, the impact frequency of the mechanical vibration excitation device 10 can be significantly improved to meet the detection requirements of higher frequencies, thereby improving the detection efficiency.

[0076] Moreover, the pre-compressed spring 142 can also play a role of buffering and shock absorption during the reciprocating motion of the excitation hammer 13. During each impact, the spring 142 can buffer the reaction force of the excitation hammer 13, reduce the stress on the internal structure of the mechanical vibration excitation device 10 at the moment of impact, and thus extend the service life of the device. In addition, during the rebound process of the spring 142, a part of the unstable factors caused by vibration can be offset, the overall stability and vibration resistance of the excitation device can be effectively improved, and the reliability of the device during high-frequency impact can be guaranteed. Furthermore, in this embodiment, the spring 142 is connected to the excitation hammer 13 through the fixing ring 143, so that the spring 142 can quickly reset the excitation hammer 13 after each impact, avoiding the reset deviation that may be caused by the spring-free design, thereby improving the motion accuracy and consistency of the excitation hammer in repeated detection, so as to facilitate the accurate acquisition of the detection results.

[0077] In some embodiments, the mechanical vibration excitation device 10 is connected to a connection base 70, and a vertically arranged square through hole 71 is opened at one end of the connection base 70, and a mechanical vibration excitation device 10 distributed vertically with the connection base 70 is passed through the square through hole 71, and the shell 11 has an open end passed through the square through hole 71 and is connected to the connection base 70 through a locking bolt 72, and the connection base 70 is provided with a slide groove 711 arranged along the vertical height direction on the inner wall of the square through hole 71, and a boss 111 slidingly matched with the slide groove 711 is provided on the shell 11, and the connection base 70 is also provided with screw holes distributed up and down on the outer wall of the square through hole 71, and locking bolts 72 are respectively provided in the screw holes; three C-type elastic clamps 73 with openings are evenly spaced and fixedly provided at the bottom end of the connection base 70 along the length direction, and the connection base 70 is connected to the cable through the three C-type elastic clamps 73, and a non-slip lining is pasted on the inner side of the C-type elastic clamp 73.

[0078] During use, the mechanical vibration excitation device 10 is fixed on the cable through the connecting base 70, and the cable is connected by three C-type elastic clamps 73 with openings evenly spaced at the bottom. The C-type clamp can firmly grasp the surface of the cable through elastic clamping to prevent the mechanical vibration excitation device 10 from slipping or loosening during operation, so that the device can be stably fixed. At the same time, the C-type elastic clamp 73 can also better adapt to the slight differences in diameters or shapes of different cables, increasing the adaptability of the device for easy installation on different cables. In this embodiment, the mechanical vibration excitation device 10 is installed on the connecting base 70, and the mechanical vibration excitation device 10 vertically passes through the connecting base 70 through the square through hole 71. Through this vertical fixing method, the mechanical vibration excitation device 10 can maintain the preset excitation direction during use, preventing the mechanical vibration excitation device 10 from causing inaccurate transmission direction of the vibration signal due to position offset. The design of the square through hole 71 and the cooperation of the locking bolt 72 further consolidate the vertical positioning of the excitation device.

[0079] The connection base 70 used in this embodiment has a square through hole 71 and a slide groove 711 in the structural design. The connection base 70 and the housing 11 of the mechanical vibration excitation device 10 are designed by the combination of the square through hole 71, the slide groove 711, the boss 111, the locking bolt 72, etc., so that a tight and stable connection is formed between the mechanical vibration excitation device 10 and the connection base 70. This method is convenient for the disassembly and adjustment of the mechanical vibration excitation device 10, and also forms a protective effect on the outside. In addition, the connection base 70 can also be used for the integrated installation of the signal acquisition module 40, the signal processing unit 50, and the power control module 60. Optionally, the signal acquisition module 40, the signal processing unit 50, and the power control module 60 are all arranged in the connection base 70, which provides a stable support for the installation of the signal acquisition module 40, the signal processing unit 50, and the power control module 60. The power input interface 61 and the power output interface 62 can be arranged on the connection base 70. Such an integrated design also optimizes the structural space, thereby improving the overall reliability and durability of the device.

[0080] Optionally, the transmission tower cable loosening detection device of the embodiment of the present application further includes a clamping assembly 80 for mounting the piezoelectric vibration sensor 20 or the resistive strain tension sensor 30, and the clamping assembly 80 includes:

[0081] The cylindrical body 81 has a sensor mounting portion 811 at the bottom for accommodating and fixing the sensor; during use, the cylindrical body 81 provides protection for the sensor to prevent the sensor from being directly affected by the external environment. Moreover, the piezoelectric vibration sensor 20 or the resistive strain tension sensor 30 is installed at the bottom of the cylindrical body 81, directly contacting the cable, which is conducive to stable detection and ensures accurate signal transmission.

[0082] Two U-shaped clamps 82 are respectively arranged on both sides of the cylindrical body 81, and each U-shaped clamp 82 is provided with a clamp 822 loaded with two torsion springs 821 on the inner side to provide elastic clamping force; the surface of the clamp 822 is pasted with a non-slip lining; a baffle 823 is hinged on one side of the bottom end of the U-shaped clamp 82, and a threaded connection hole 825 for connecting a tightening bolt 824 is provided on the other side of the bottom end of the U-shaped clamp 82, and a connecting through hole 8231 that matches the threaded connection hole 825 and can be passed through by the tightening bolt 824 is provided on the baffle 823. After the U-shaped clamp 82 is locked and connected with the baffle 823 by tightening the bolt 824, the cable in the U-shaped clamp 82 is locked and fixed. In the embodiment of the present application, the anti-slip lining pasted on the surface of the clamp 822 and the anti-slip lining pasted on the inner side of the C-shaped elastic clamp 73 are made of rubber material or silicone material, which can effectively increase the friction. Moreover, both rubber and silicone materials have a certain flexibility, which can provide buffering during clamping and reduce damage to the surface of the cable.

[0083] In this embodiment, a clamping assembly 80 is added to the transmission tower cable loosening detection device of the present application. The clamping assembly 80 can be used to independently install the piezoelectric vibration sensor 20 or the resistive strain type tension sensor 30. When in use, the piezoelectric vibration sensor 20 and the resistive strain type tension sensor 30 can be installed on a clamping assembly 80 respectively. The clamping assembly 80 of this embodiment has a cylindrical body 81, and the sensor mounting portion 811 at the bottom of the cylindrical body 81 is specially designed to accommodate and fix the sensor to prevent the sensor from loosening during use. At the same time, the surface of the clamping plate 822 is affixed with an anti-slip lining, which allows the sensor to remain stable even if it is subjected to vibration or external force impact during operation. Moreover, each U-shaped clamp 82 of the clamping assembly 80 is equipped with a clamping plate 822 loaded with a torsion spring 821. This design allows the clamping assembly 80 to automatically apply an elastic clamping force during installation, adapting to cables of different thicknesses, without the need for additional tools, and is simple and quick. The torsion spring 821 enables the clamp 822 to clamp the cable, which is not prone to sliding or loosening, thereby ensuring the stable installation of the sensor. In addition, there is a baffle 823 on one side of the bottom end of the U-shaped clamp 82, and a threaded connection hole 825 on the other side. The baffle 823 and the U-shaped clamp 82 are fixed by tightening the bolt 824. In this way, when the bolt 824 is tightened, the clamping assembly 80 can be firmly locked on the cable, and it will not be easily loosened even if it is subjected to vibration or other external forces. This design not only ensures the safety of the sensor in various harsh environments, but also reduces the number and cost of maintenance. This embodiment uses the ingenious clamping structure design of the clamping assembly 80 to make the installation of the sensor more secure and convenient, while providing better protection and safety. It is suitable for long-term use in harsh outdoor conditions and helps to ensure the stability and reliability of detection.

[0084] The method and process of using the transmission tower cable loosening detection device of the embodiment of the present application are described in detail as follows:

[0085] 1. Preparation and connection

[0086] Select the detection position, and select the detection point of the cable near the anchor end of the cable or at the middle fixed node. These locations are areas with greater force and are easily affected by the environment and external forces.

[0087] The clamping assembly 80 is installed on the cable. Specifically, the two clamping assemblies 80 for installing the piezoelectric vibration sensor 20 and the resistive strain tension sensor 30 are clamped on the cable through the U-shaped clamp 82. The clamping plate 822 of the U-shaped clamp 82 can provide sufficient clamping force to preliminarily fix the U-shaped clamp 82 on the zipper.

[0088] 2. Sensor installation

[0089] The piezoelectric vibration sensor 20 is installed in the sensor installation part 811 of the cylindrical body 81, so that the piezoelectric vibration sensor 20 is in close contact with the surface of the cable, and then the clamp is firmly fixed on the cable by tightening the bolt 824 through the connection hole 8231 of the baffle 823 and the threaded connection hole 825 of the U-shaped clamp 82 to prevent it from loosening. The stability of the piezoelectric vibration sensor 20 can be ensured by the cooperation of the clamp 822 loaded with the torsion spring 821 and the baffle 823 and the anti-slip lining pasted on the surface of the clamp 822. In the same way, the resistance strain tension sensor 30 is fixed in the sensor installation part 811 of another clamping assembly 80 to ensure stable installation.

[0090] 3. Installation of mechanical vibration excitation device

[0091] The mechanical vibration excitation device 10 is installed at the selected detection position, and the mechanical vibration excitation device 10 is fixed on the cable through the connection base 70 to which it is connected, so that its output end can apply mechanical vibration to the cable. Confirm that the mechanical vibration excitation device 10 is connected to the power control module 60 through the cable to ensure that the mechanical vibration excitation device 10 can obtain the required driving power.

[0092] 4. Power control and startup

[0093] Turn on the power control module 60 and check whether the power output interface 62 is supplying power normally. Adjust the PWM controller 64 to set the required current frequency and output voltage.

[0094] The mechanical vibration excitation device 10 is started so that it starts to reciprocate under the action of the drive motor 12, and mechanical vibration is applied to the cable.

[0095] 5. Signal acquisition and processing

[0096] During signal acquisition, ensure that the cables of the signal acquisition module 40, the piezoelectric vibration sensor 20 and the resistive strain type tension sensor 30 are connected in place. During the detection process, the piezoelectric vibration sensor 20 acquires vibration signals, and the resistive strain type tension sensor 30 acquires stress signals. The two signals are synchronously transmitted through the signal acquisition module 40. The signal acquisition module 40 performs preliminary filtering and merging processing, and transmits the data to the signal processing unit 50.

[0097] 5. Signal analysis and result output

[0098] The signal amplification module 51 in the signal processing unit 50 amplifies the vibration signal and the stress signal, and the filtering module 52 removes noise and extracts the target frequency signal. The analog-to-digital conversion module 53 converts the filtered analog signal into a digital signal and transmits it to the signal feature extraction module 54. The signal feature extraction module 54 analyzes the digital signal and extracts characteristic parameters, such as frequency and amplitude, to determine the loose state of the cable. The processing results can be output through a display device or a memory to record the detection data.

[0099] 6. Disassembly and resetting

[0100] After the detection is completed, the power control module 60 is turned off and the power is disconnected, and then the sensor, the clamping assembly 80 and the mechanical vibration excitation device 10 are disassembled in sequence to avoid damage to the equipment.

[0101] The present application also provides a method for nondestructive detection of loose power transmission tower cables, using the power transmission tower cable loose detection device provided in the above embodiment. The detection method specifically includes the following steps:

[0102] Step 1: The mechanical vibration excitation device 10 is fixedly installed near the anchor end or at the middle fixed node of the transmission tower cable, and the driving power is provided to the mechanical vibration excitation device 10 through the power control module 60, so that the mechanical vibration excitation device 10 can generate mechanical vibration and apply the vibration to the cable;

[0103] Step 2: Install a piezoelectric vibration sensor 20 and a resistive strain type tension sensor 30 on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device 10 to detect vibration signals and stress signals respectively; install the piezoelectric vibration sensor 20 and the resistive strain type tension sensor 30 on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device 10 to achieve synchronous collection of dual signals. This arrangement enables the vibration signal and stress signal to accurately reflect the stress condition and loose state of the cable, and the synchronous collection and analysis of the dual signals helps to obtain a more accurate loose state judgment, avoids the errors that may be caused by a single signal, and improves the reliability and accuracy of detection.

[0104] Step 3: starting the mechanical vibration excitation device 10 to generate impact vibration and apply it to the cable, inducing vibration and tension change of the cable;

[0105] Step 4: The vibration signal collected by the piezoelectric vibration sensor 20 and the stress signal collected by the resistance strain type tension sensor 30 are synchronously received and transmitted by the signal acquisition module 40, and the signal acquisition module 40 performs preliminary processing on the signal and transmits it to the signal processing unit 50;

[0106] Step 5: In the signal processing unit 50, the received vibration signal and stress signal are analyzed and processed to determine the loose state of the cable. The dual feature analysis of the vibration signal and the stress signal enables the detection to not only identify whether the cable is loose, but also provide more comprehensive data support for diagnosing the severity and location characteristics of the looseness.

[0107] The detection method is reasonably designed and has simple steps. The detection method installs a mechanical vibration excitation device 10 at the anchor end or the middle fixed node, and combines the power control module 60 to provide stable power support. The user only needs to install and start each device step by step according to the steps to efficiently complete the detection process. The step-by-step design of steps 1 to 5 makes the detection operation intuitive and controllable, suitable for rapid deployment and evacuation in complex environments. At the same time, the dual-signal synchronous detection and integrated processing process simplifies the subsequent analysis steps, so that the detection work can be completed quickly and efficiently, meeting the on-site application requirements of loosening detection of transmission tower cables.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, ordinary technicians in the field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A transmission tower cable loosening detection device, characterized in that: It includes a mechanical vibration excitation device, a piezoelectric vibration sensor, a resistive strain type tension sensor, a signal acquisition module, a signal processing unit and a power supply control module; The mechanical vibration excitation device is arranged on the cable of the transmission tower and installed near the anchor end or at the middle fixed node of the cable of the transmission tower, and is used to generate mechanical vibration and apply it to the cable to cause vibration and tension change of the cable; The piezoelectric vibration sensor is arranged on the cable and close to the mechanical vibration excitation device, and is used to detect the vibration signal caused by the mechanical vibration excitation device; The resistance strain type tension sensor is arranged on the cable and close to the mechanical vibration excitation device, and is used to detect the stress signal generated by the cable during vibration; The signal acquisition module is connected to the piezoelectric vibration sensor and the resistive strain tension sensor respectively through cables, and is used to simultaneously receive the vibration signal and the stress signal; The signal processing unit is connected to the signal acquisition module via a cable, and is used to analyze and process the received signal to determine the loose state of the cable; The power control module is connected to the mechanical vibration excitation device, the signal acquisition module and the signal processing unit respectively through cables to provide the required power support.

2. The transmission tower cable loosening detection device according to claim 1, characterized in that: The piezoelectric vibration sensor and the resistive strain type tension sensor are both arranged on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device to synchronously detect the vibration and tension signals caused by the mechanical vibration excitation device; The vicinity of the anchor end is within a range of no more than 30-50 cm from the anchor point where the cable is fixed on the iron tower or the foundation structure; the intermediate fixed node is the position of the support or reinforcement structure along the length direction of the cable or a position no more than 20-30 cm away from it.

3. The transmission tower cable loosening detection device according to claim 2, characterized in that: The signal acquisition module includes a vibration signal receiving module, a stress signal receiving module and a signal preprocessing module; the vibration signal receiving module is connected to the piezoelectric vibration sensor through a cable, and is used to receive the vibration signal and perform preliminary filtering, and the output end of the vibration signal receiving module is connected to the signal preprocessing module; the stress signal receiving module is connected to the resistance strain type tension sensor through a cable, and is used to receive the stress signal and perform preliminary filtering, and the output end of the stress signal receiving module is connected to the signal preprocessing module; The signal preprocessing module is used to combine the received signals and transmit them to the signal processing unit. The output end of the signal preprocessing module is connected to the signal processing unit through a cable.

4. The transmission tower cable loosening detection device according to claim 3, characterized in that: The signal processing unit includes a signal amplification module, a filtering module, an analog-to-digital conversion module and a signal feature extraction module; The signal amplification module is used to amplify the received vibration signal and stress signal to improve the signal processing accuracy. The input end of the signal amplification module is connected to the output end of the signal acquisition module through a cable, and is used to amplify the received vibration signal and stress signal. The output end of the signal amplification module is connected to the filtering module. The filtering module is connected to the output end of the signal amplification module, and is used to remove noise and extract signals within the target frequency range. The output end of the filtering module is connected to the analog-to-digital conversion module; the analog-to-digital conversion module is connected to the output end of the filtering module, and is used to convert the filtered analog signal into a digital signal. The output end of the analog-to-digital conversion module is connected to the signal feature extraction module; the signal feature extraction module is used to analyze the amplified, filtered and digitized signals to determine the loose state of the cable. The input end of the signal feature extraction module is connected to the analog-to-digital conversion module, and its output end is used to output the processing results.

5. The transmission tower cable loosening detection device according to claim 3, characterized in that: The power control module includes a power input interface, a power output interface, a voltage regulating unit, a PWM controller and a power management unit; the power input interface is used to receive an external power input and is electrically connected to the voltage regulating unit; the voltage regulating unit is connected to the PWM controller, and is used to regulate the input voltage and provide a stable voltage to the PWM controller; The PWM controller is connected to the power management unit, and is used to adjust the pulse frequency and width of the output current, and transmit the adjusted current to the power output interface; The power management unit is connected to the power output interface for monitoring and protecting the output current and providing current stabilization and overcurrent protection functions; the power output interface is respectively connected to the mechanical vibration excitation device, the signal acquisition module and the signal processing unit through cables for providing stable power output to each module.

6. The transmission tower cable loosening detection device according to any one of claims 1 to 5, characterized in that: The mechanical vibration excitation device includes a shell, a driving motor, an excitation hammer head and a guide mechanism; the driving motor is a linear motor, fixedly installed at the rear end inside the shell, and is used to drive the excitation hammer head to perform reciprocating linear motion. The output shaft of the driving motor is connected to the rear end of the excitation hammer head through a coupling, and the shell is a square shell; the excitation hammer head is a cylindrical steel structure, and an arc-shaped groove is provided at the front end of the excitation hammer head. The front end of the excitation hammer head faces an opening opened at the front end of the shell, and the excitation hammer head can generate reciprocating impact motion under the electric drive of the driving motor; the guide mechanism includes a guide sleeve fixed to the front end of the shell, and the guide sleeve is slidably matched with the excitation hammer head.

7. The transmission tower cable loosening detection device according to claim 6, characterized in that: The guide mechanism also includes a spring, which is arranged at the rear of the excitation hammer head. A fixing ring located at the rear section of the excitation hammer head is fixedly sleeved on the excitation hammer head. The front end of the spring is connected to the rear end of the guide sleeve, and the rear end of the spring is connected to the fixing ring. The spring is located between the guide sleeve and the fixing ring and is in a pre-compression state. When the excitation hammer head moves forward under the drive of the drive motor, the spring can be further compressed to store elastic potential energy. When the excitation hammer head completes the impact and is released, the elastic force of the spring can prompt the excitation hammer head to return to its position quickly.

8. The transmission tower cable loosening detection device according to claim 6, characterized in that: The mechanical vibration excitation device is connected to a connecting base, and a vertically arranged square through hole is provided at one end of the connecting base, and the mechanical vibration excitation device distributed vertically with the connecting base is passed through the square through hole, and the shell has an open end which is passed through the square through hole and is connected to the connecting base through a locking bolt, and the connecting base is provided with a slide groove arranged along the vertical height direction on the inner wall of the square through hole, and the shell is provided with a boss that slides with the slide groove, and the connecting base is also provided with screw holes distributed up and down on the outer wall of the square through hole, and the locking bolts are respectively provided in the screw holes; three C-shaped elastic clamps with openings are fixedly provided at the bottom end of the connecting base at evenly spaced intervals along the length direction, and the connecting base is connected to the cable through the three C-shaped elastic clamps, and a non-slip lining is pasted on the inner side of the C-shaped elastic clamp.

9. The transmission tower cable loosening detection device according to claim 7 or 8, characterized in that: It also includes a clamping assembly for mounting the piezoelectric vibration sensor or the resistive strain tension sensor, the clamping assembly comprising: A cylindrical body, with a sensor mounting portion at the bottom for accommodating and fixing the sensor; Two U-shaped clamps are respectively arranged on both sides of the cylindrical body, and two clamps loaded with torsion springs to provide elastic clamping force are arranged on the inner side of each U-shaped clamp; a non-slip lining is pasted on the surface of the clamp; a baffle is hinged on one side of the bottom end of the U-shaped clamp, and a threaded connection hole for connecting a tightening bolt is provided on the other side of the bottom end of the U-shaped clamp, and a connecting through hole that matches the threaded connection hole and can be passed through by the tightening bolt is provided on the baffle. After the U-shaped clamp is locked and connected to the baffle by the tightening bolt, the cable in the U-shaped clamp is locked and fixed.

10. A nondestructive detection method for loosening of transmission tower cables, characterized in that: The transmission tower cable loosening detection device according to any one of claims 1 to 9 comprises the following steps: Step 1: The mechanical vibration excitation device is fixedly installed near the anchor end or at the middle fixed node of the transmission tower cable, and the driving power is provided to the mechanical vibration excitation device through the power control module, so that the mechanical vibration excitation device can generate mechanical vibration and apply the vibration to the cable; Step 2: Install a piezoelectric vibration sensor and a resistive strain tension sensor on the surface of the cable no more than 30 cm away from the mechanical vibration excitation device to detect vibration signals and stress signals respectively; Step 3: Start the mechanical vibration excitation device to generate impact vibration and apply it to the cable, inducing vibration and tension change of the cable; Step 4: The vibration signal collected by the piezoelectric vibration sensor and the stress signal collected by the resistance strain type tension sensor are synchronously received and transmitted through the signal acquisition module, and the signal acquisition module performs preliminary processing on the signal and transmits it to the signal processing unit; Step 5: In the signal processing unit, the received vibration signal and stress signal are analyzed and processed to determine the loose state of the cable.

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