A method and system for monitoring broken wires based on acoustic emission technology

Abstract

The present application discloses a wire break monitoring method and system based on acoustic emission technology, which belongs to the field of wire break monitoring technology. The method includes: determining sensor setting information based on basic information of monitored cables and prestressed steel wires, deploying acoustic emission sensors according to the sensor setting information, collecting acoustic emission signals of acoustic emission sensors, performing wire break factor calculation based on the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact, obtaining wire break factor calculation results, using wire break factor evaluation criteria, evaluating wire break status based on the wire break factor calculation results and acoustic emission signals, obtaining wire break evaluation results, and generating alarm information when the wire break evaluation results meet wire break event conditions. The method solves the technical problems in the prior art of low monitoring and identification accuracy of wire break signals and inability to monitor in real time and for a long time. The technical effect of improving the accuracy and timeliness of wire break signal monitoring is achieved.

Description

Technical Field

[0001] The present application relates to the technical field of broken wire monitoring, and in particular to a broken wire monitoring method and system based on acoustic emission technology. Background Art

[0002] With the rapid development of economy and science and technology, the number of bridges in my country is increasing, and the types of bridges are becoming more and more diverse. For large-span bridges, especially cross-sea bridges, they are mainly suspension bridges, cable-stayed bridges or post-tensioned concrete bridges. In these bridges, cables and prestressed steel wires need to bear the load directly. Research on the safety of cables and prestressed steel wires is of great significance to ensuring the safety of bridges in my country.

[0003] At present, if cables and prestressed steel wires break during bridge operation, the bearing capacity of other steel bars will increase, thereby accelerating the breaking of other cables. When a certain number of broken wires is reached, the bearing capacity of cables and prestressed steel wires will be reduced, and even the entire cable will be broken, seriously affecting the structural safety of the bridge, and even causing the sudden collapse of the entire bridge, resulting in a major accident.

[0004] However, in the process of wire breakage monitoring, the amplitude is only expressed as the signal size in the monitoring system. When encountering strong mechanical vibration, external impact, extreme weather and other situations, it will also cause the appearance of extremely large amplitude signals, or cause the cumulative energy to rise and abnormal points in the energy curve. The existing wire breakage monitoring method cannot identify abnormal situations one by one, and it is easy to cause false alarms of wire breakage in the identification and judgment criteria of broken wire signals. There are technical problems in the existing technology that the monitoring and identification accuracy of broken wire signals is low, and real-time and long-term monitoring cannot be performed. Summary of the invention

[0005] The purpose of the present application is to provide a broken wire monitoring method and system based on acoustic emission technology, so as to solve the technical problems in the prior art of low monitoring and identification accuracy of broken wire signals and inability to perform real-time and long-term monitoring.

[0006] In view of the above problems, the present application provides a broken wire monitoring method and system based on acoustic emission technology.

[0007] In a first aspect, the present application provides a wire breakage monitoring method based on acoustic emission technology, wherein the method comprises: determining sensor setting information based on basic information of monitored cables and prestressed steel wires, and deploying acoustic emission sensors according to the sensor setting information; collecting acoustic emission signals of the acoustic emission sensors, wherein the acoustic emission signals include the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact; performing wire breakage factor calculation based on the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact to obtain a wire breakage factor calculation result; utilizing a wire breakage factor evaluation criterion to evaluate the wire breakage status according to the wire breakage factor calculation result and the acoustic emission signal to obtain a wire breakage evaluation result; and generating an alarm message when the wire breakage evaluation result meets a wire breakage event condition.

[0008] On the other hand, the present application also provides a broken wire monitoring system based on acoustic emission technology, wherein the system includes: a sensor deployment module, the sensor deployment module is used to determine sensor setting information based on the basic information of the monitored cable and prestressed steel wire, and deploy the acoustic emission sensor according to the sensor setting information; an acoustic emission signal acquisition module, the acoustic emission signal acquisition module is used to collect the acoustic emission signal of the acoustic emission sensor, and the acoustic emission signal includes the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact; a broken wire factor calculation module, the broken wire factor calculation module is used to perform a broken wire factor calculation based on the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact to obtain a broken wire factor calculation result; an evaluation result acquisition module, the evaluation result acquisition module is used to use a broken wire factor evaluation criterion, and perform a broken wire state evaluation according to the broken wire factor calculation result and the acoustic emission signal to obtain a broken wire evaluation result; an alarm information generation module, the alarm information generation module is used to generate an alarm message when the broken wire evaluation result meets the broken wire event condition.

[0009] One or more technical solutions provided in this application have at least the following technical effects or advantages:

[0010] This application determines the sensor setting information based on the basic information of the monitored cables and prestressed steel wires, and then arranges the position and number of acoustic emission sensors, collects the acoustic emission signals of the acoustic emission sensors, wherein the acoustic emission signals include the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact, and then performs a wire breaking factor calculation to obtain a wire breaking factor calculation result, uses a wire breaking factor evaluation criterion, and performs a wire breaking state evaluation based on the wire breaking factor calculation result and the acoustic emission signal to obtain a wire breaking evaluation result, and generates an alarm message when the wire breaking evaluation result meets the wire breaking event condition. The technical effect of improving the recognition accuracy of the wire breaking signal, reducing the recognition error, and improving the detection accuracy is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the present application or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only exemplary, and for ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0012] Figure 1 A schematic flow chart of a broken wire monitoring method based on acoustic emission technology provided in an embodiment of the present application;

[0013] Figure 2 A schematic diagram of the arrangement of main cable sensors in a wire break monitoring method based on acoustic emission technology provided in an embodiment of the present application;

[0014] Figure 3 A schematic diagram of the arrangement of the sensors for the inclined cables in a wire breakage monitoring method based on acoustic emission technology provided in an embodiment of the present application;

[0015] Figure 4 A schematic diagram of the arrangement of the suspension rod sensors in a wire break monitoring method based on acoustic emission technology provided in an embodiment of the present application;

[0016] Figure 5 A diagram showing the structure of a sensor in a broken wire monitoring method based on acoustic emission technology provided in an embodiment of the present application;

[0017] Figure 6 This is a structural schematic diagram of a broken wire monitoring system based on acoustic emission technology in this application;

[0018] Explanation of the reference numerals: sensor deployment module 11 , acoustic emission signal acquisition module 12 , broken wire factor calculation module 13 , evaluation result acquisition module 14 , alarm information generation module 15 . DETAILED DESCRIPTION

[0019] This application provides a wire-broken monitoring method and system based on acoustic emission technology, which solves the technical problems in the prior art of low monitoring and identification accuracy of wire-broken signals and inability to perform real-time and long-term monitoring, thereby achieving the technical effect of improving the accuracy and timeliness of wire-broken signal monitoring.

[0020] The acquisition, storage, use, and processing of data in the technical solution of this application comply with the relevant provisions of national laws and regulations.

[0021] Below, the technical solutions in the present application will be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments of the present application. It should be understood that the present application is not limited to the example embodiments described herein. Based on the embodiments of the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application. It should also be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, rather than all of them.

[0022] Embodiment 1

[0023] like Figure 1 As shown, the present application provides a broken wire monitoring method based on acoustic emission technology, wherein the method comprises:

[0024] Step S100: determining sensor setting information based on basic information of the monitored cables and prestressed steel wires, and arranging acoustic emission sensors according to the sensor setting information;

[0025] Furthermore, based on the basic information of the monitored cables and prestressed steel wires, the sensor setting information is determined, and the acoustic emission sensors are arranged according to the sensor setting information. Step S100 of the embodiment of the present application also includes:

[0026] Step S110: The basic information includes the monitored length, steel wire type, prestressing size, and key parts. When the key part is the main cable monitoring, the acoustic emission sensor is arranged along the main cable direction; when the key part is the inclined cable monitoring, the acoustic emission sensor is arranged along the inclined cable direction at the two anchor ends of the cable; when the key part is the suspension rod monitoring, the acoustic emission sensor is arranged along the suspension rod direction at the lower anchor end or the upper anchor end;

[0027] Step S120: performing a center impact test on the monitored cables and prestressed steel wires to obtain signal attenuation characteristics;

[0028] Step S130: determining sensor spacing information according to the signal attenuation characteristics, wherein the maximum amplitude attenuation between two adjacent sensors is no greater than 30 dB.

[0029] Specifically, when determining the sensor setting information, it is necessary not only to consider the restrictions on the installation of sensors caused by the structure of the monitored cable and prestressed steel wire itself, but also to consider the attenuation characteristics of the signal obtained after the impact test of the monitored cable on site by a center punch to determine the final installation position of the sensor.

[0030] Specifically, the basic information can reflect the information of the monitored cable and prestressed steel wire structure, including the monitored length, steel wire model, prestressing size, and key parts. Among them, the key parts are the parts to be monitored. The sensor layout position, spacing and number can be determined based on the basic information.

[0031] Preferably, Figure 2 As shown, when the key part is the main cable monitoring, the acoustic emission sensor is arranged along the main cable direction, and can be arranged on the entire main cable, or on the local main cable, such as: the interrupted part of the suspension main cable and the position of the anchor end cable clamp.

[0032] Preferably, Figure 3 As shown, when the key part is the cable, the acoustic emission sensor is arranged along the cable direction and at the two anchor ends of the cable. Optionally, the acoustic emission sensor can be arranged on the entire cable.

[0033] Preferably, Figure 4 As shown, when the key part is the boom monitoring, the acoustic emission sensor is arranged at the lower anchor end or the upper anchor end along the direction of the boom.

[0034] Exemplarily, when monitoring steel wires or steel strands in a post-tensioned structure, acoustic emission sensors are arranged along the direction of the steel wires, on the outer concrete wall, at the corners and at the anchor ends.

[0035] Specifically, the center impact test should be performed between at least two acoustic emission sensors. In order to ensure the accurate collection of acoustic signals, it is necessary to ensure that the distance between two adjacent sensors can meet the transmission of acoustic signals through a center impact test. When performing a center impact test, the center impact needs to be perpendicular to the cable and prestressed steel wire. During the test, first impact next to any sensor, then impact in the middle of the two sensors, and finally impact next to the other sensor to obtain the signal attenuation characteristics. Among them, the signal attenuation characteristics are the degree of signal attenuation as the signal decreases from the center of the center impact to both ends.

[0036] Specifically, by impacting next to any sensor, the signal attenuation from one sensor to another can be obtained; by impacting between two sensors, the signal attenuation from the middle to the two sensors can be determined; by impacting next to another sensor, the reverse signal attenuation can be obtained. In summary, the signal attenuation characteristics can be obtained. By ensuring that the maximum amplitude attenuation between two adjacent sensors is no more than 30dB, the sensor spacing information can be determined.

[0037] Specifically, the sensor setting information is the layout position and quantity information of the acoustic emission sensors determined according to the basic information of the monitored cables and prestressed steel wires. By accurately setting the position of the acoustic emission sensors, the accuracy of signal collection is improved, thereby achieving a technical effect of improving monitoring accuracy.

[0038] Preferably, when installing the acoustic emission sensor, the cable wrapping layer should be avoided and a strong adhesive should be used. If necessary, an external physical fixing device can be added, such as a magnetic clamp, a mechanical clamp, a bandage, etc.

[0039] Preferably, when the acoustic emission sensors are arranged according to the sensor setting information, the surface of the installation location needs to be cleaned and processed to remove dust, oil stains and rust paint to ensure that the surface of the installation location is neat and flat.

[0040] Step S200: collecting an acoustic emission signal of the acoustic emission sensor, wherein the acoustic emission signal includes an amplitude of the acoustic emission impact sensor output end and a duration of the acoustic emission impact;

[0041] Furthermore, before collecting the acoustic emission signal of the acoustic emission sensor, step S200 in the embodiment of the present application further includes:

[0042] Step S210: performing an AST test on all deployed acoustic emission sensors, wherein the AST test is to use an acoustic emission device to automatically transmit a pulse signal in turn, receive an echo signal through the acoustic emission sensor, and determine the AST test result according to the received echo signal;

[0043] Step S220: performing a wave velocity test on the acoustic emission sensor, wherein the wave velocity test is applied between at least two of the acoustic emission sensors, and the sound velocity is calculated using the setting distance of the acoustic emission sensors, the time difference of receiving the impact excitation signal, and the impact position.

[0044] Furthermore, the acoustic emission signal of the acoustic emission sensor is collected, and step S210 of the embodiment of the present application further includes:

[0045] Step S230: setting a threshold for each acoustic emission signal collection channel, and determining whether the acoustic emission signal of the current channel meets the threshold for the acoustic emission signal collection channel;

[0046] Step S240: When the acoustic emission signal in the channel does not meet the threshold of the acoustic emission signal collection channel, the channel does not collect the signal; when the acoustic emission signal in the channel meets the threshold of the acoustic emission signal collection channel, the acoustic emission signal in the channel is collected to obtain the signal basic parameter amplitude, signal frequency, count, signal duration, signal occurrence time, and signal arrival time to obtain the acoustic emission signal.

[0047] Specifically, after all acoustic emission sensors are deployed, the working status of the system and sensors is determined by performing an AST test, and the transmission speed of the acoustic emission sensors is tested by performing a wave velocity test.

[0048] Specifically, multiple groups of acoustic emission sensors automatically transmit pulse signals in turn, and the received echo signals are used to analyze and determine whether the sensors are working properly and the changes in sensitivity, providing a basis for subsequent calibration of the acoustic emission sensors. Among them, at least 5 groups of tests should be performed, and the pulse signal interval can be adjusted by the staff according to the actual situation, and there is no limit here.

[0049] Specifically, the wave velocity test is carried out by a central impact at a known position between at least two acoustic emission sensors to excite a signal. Each sensor receives the central impact signal, and the sound velocity is obtained by counting the impact time difference and impact position of each received signal and the setting distance of the acoustic emission sensor.

[0050] Specifically, the acquisition and processing of acoustic emission signals are controlled by an acoustic emission acquisition and processing card, which is a multi-channel acquisition card with a bandwidth of 1Khz-1000Khz, a time synchronization rate between channels that can reach or exceed 0.1 microseconds, and each channel can perform data acquisition and acoustic emission characteristic extraction independently of other channels according to their own threshold settings.

[0051] Specifically, when the acoustic emission signal is higher than the set threshold, the transient signal of the preset sampling length is collected and processed to filter out the noise signal below the threshold; the signal collected by the threshold and the front-end filtering is processed by secondary filtering to eliminate the high-amplitude and high-intensity signals generated by the noise.

[0052] Specifically, the acoustic emission sensor converts the collected analog signal into a voltage signal, transmits it to the acquisition card along the signal line, and processes the voltage signal through the A / D conversion module and the analog filter module to obtain the acoustic emission signal, providing basic data for subsequent judgment of the broken wire signal.

[0053] Step S300: performing a broken wire factor calculation based on the amplitude of the output end of the acoustic emission impact sensor and the duration of the acoustic emission impact to obtain a broken wire factor calculation result;

[0054] Further, the broken wire factor calculation is performed based on the amplitude of the output end of the acoustic emission impact sensor and the duration of the acoustic emission impact to obtain the broken wire factor calculation result. Step S300 of the embodiment of the present application also includes:

[0055] Step S310: According to the broken wire factor calculation formula: A broken wire factor calculation is performed to obtain the broken wire factor calculation result, wherein Q is the broken wire factor, A is the amplitude of the output end of the acoustic emission impact sensor, T is the duration of the acoustic emission impact, F is the broken wire force, Fr is the maximum broken wire force reference value, Ar is the amplitude of the sensor output end corresponding to the full scale of the equipment used, and Tr is the maximum duration of the broken wire impact.

[0056] Specifically, the greater the amplitude of the acoustic emission impact and the longer the duration, the greater the wire breaking force. The unit of the amplitude A is volt, the unit of the duration T is second, and the unit of the wire breaking force F is volt-second. Through the wire breaking factor calculation formula, the ratio between the wire breaking force and the maximum wire breaking force reference value can be calculated, which can be used as a basis for judging whether the wire is broken.

[0057] Preferably, the amplitude of the broken wire force can also be expressed by the logarithmic amplitude of the acoustic emission, in which case the unit of the amplitude A is decibel, and the unit of the force is decibel-second.

[0058] Step S400: using the broken wire factor evaluation criteria, evaluating the broken wire state according to the broken wire factor calculation result and the acoustic emission signal, and obtaining a broken wire evaluation result;

[0059] Furthermore, the broken wire factor evaluation criteria, step S400 of the embodiment of the present application includes:

[0060] Step S410: screening the collected acoustic emission signals by using intelligent logic judgment;

[0061] Step S420: according to the frequency characteristics of the signal frequency, the frequency characteristics of the acoustic emission sensor are consistent;

[0062] Step S430: the emission signals received by the multiple acoustic emission sensors and the locations where the multiple acoustic emission sensors are set satisfy the signal attenuation law;

[0063] Step S440: the amplitude of the acoustic emission impact sensor output terminal is expressed in decibels, and the distribution of the wire breakage factor calculation result Q value is calculated in volts to satisfy 0≤Q≤1;

[0064] Step S450: The arrival time of the acoustic emission signal received by each channel meets the event definition time range.

[0065] Specifically, the broken wire factor evaluation criteria are used to analyze, process and identify the acoustic emission signal to obtain the rules of the broken wire state. Through the obtained parameter size and distribution range of the acoustic emission signal, a large amount of noise data is eliminated according to the intelligent logic judgment and a small amount of valid data that meets the conditions is retained and stored. Data consistent with the frequency characteristics of the acoustic emission sensor is retained, where the frequency characteristics include: amplitude frequency and frequency center moment.

[0066] Specifically, the signal attenuation law states that the amplitude of the signal will show an attenuation characteristic as the distance between the sensor and the broken wire position increases, and the ratio of the signal amplitude attenuation should be close to the signal amplitude attenuation ratio obtained by the center punch test.

[0067] Specifically, when the amplitude is in decibels, the Q value of the broken wire factor calculation result is larger than the Q value of the broken wire factor calculation result calculated when the amplitude is in volts, and the noise is more likely to be judged as a broken wire. However, the distribution range of the Q value still satisfies 0≤Q≤1 in this case.

[0068] Specifically, the event definition time range means that the arrival time of the acoustic emission impact signal received by each channel should be within the range determined by the event definition time. According to the above criteria, the signal retained after filtering should satisfy the positioning law, that is, the broken wire position calculated by the time difference of the broken wire signal arriving at each channel in an event has consistency and rationality, that is, the broken wire position deviation calculated by the time difference between the two channels should be within a certain range δ, and the control range of δ can be obtained by the center impact calibration test. The final determined broken wire position should also meet rationality, that is, the position should be within the sensors at the two ends, and should not be outside the sensors at the two ends.

[0069] Further, by using the broken wire factor evaluation criteria, the broken wire state is evaluated according to the broken wire factor calculation result and the acoustic emission signal to obtain a broken wire evaluation result. In the embodiment of the present application, step S400 further includes:

[0070] Step S460: after the acoustic emission signal is evaluated by the broken wire factor evaluation criteria, the broken wire position is determined according to the time difference of the acoustic emission signal obtained by each channel and the sound velocity obtained in the wave velocity test;

[0071] Step S470: determining the wire breaking time according to the wire breaking position, the signal arrival time of the received acoustic emission signal, and the sound velocity;

[0072] Step S480: determining the number of broken wires according to the counting information of the acoustic emission signal;

[0073] Step S490: Obtain the broken wire evaluation result using the broken wire position, broken wire time, broken wire quantity, and broken wire factor calculation results.

[0074] Specifically, the determined wire breaking position, wire breaking time and number of broken wires all have definite values, and a deterministic wire breaking evaluation result can be obtained. By multiplying the time difference of the acoustic emission signal by the speed of sound, the distance difference between each channel and the wire breaking position can be obtained, and the wire breaking position can be obtained in combination with the layout position of the acoustic emission sensor.

[0075] Specifically, by obtaining the distance between the broken wire position and the received acoustic emission signal according to the broken wire position, and combining the speed of sound, the transmission time of the signal from the broken wire position to the receiving position is obtained, and then the broken wire time can be obtained according to the signal arrival time.

[0076] Specifically, after a wire breaks, an acoustic emission signal is generated, and the number of broken wires can be determined by counting the acoustic emission signals. The broken wire evaluation result can accurately reflect the broken wire situation.

[0077] Preferably, the broken wire evaluation results will be stored in the broken wire database for subsequent trend and statistical analysis, and the total broken wire situation can also be accumulated in terms of time, quantity, and location. According to the specific requirements of the cable and monitoring, the location can be Δ (such as Δ = 0.5m) as the distance interval, and the accumulated number of broken wires within each Δ range is counted. In addition to storing the broken wire information monitored each time in the database, an email alarm reminder can be sent to the control room or a designated mailbox through the network.

[0078] Step S500: When the broken wire evaluation result meets the broken wire event condition, an alarm message is generated.

[0079] Furthermore, when the broken wire evaluation result meets the broken wire event condition, an alarm message is generated. Step S500 of the embodiment of the present application further includes:

[0080] Step S510: when the wire-breaking factor calculation result Q is less than 0.1, it is a non-wire-breaking signal;

[0081] Step S520: When the broken wire factor calculation result Q is close to 1, it is a broken wire signal, and the alarm information is sent.

[0082] Specifically, the wire breaking event condition refers to the condition under which the wire breaking is determined to occur. When the wire breaking factor calculation result Q is less than 0.1, it can be determined that the wire breaking does not occur, and the data is saved in the on-site host and automatically transferred to a CSV format file.

[0083] Specifically, when the wire breaking factor calculation result Q is close to 1, it is determined that a wire breaking event has occurred, the data is saved in the on-site host, and automatically transferred to a CSV format file, the system interface prompts an alarm, and at the same time sends an alarm message to the server through the network. The alarm message includes: the time point and location of the wire breaking.

[0084] Further, such as Figure 5 As shown, the acoustic emission sensor has a built-in amplifier with an amplification factor of 6-60dB, a protection grade of IP66, and an integrated AST pulse generation module.

[0085] In summary, the broken wire monitoring method based on acoustic emission technology provided by the present application has the following technical effects:

[0086] The embodiment of the present application sets the position and number of acoustic emission sensors according to the conditions of the monitored cables and prestressed steel wires of the bridge, so that broken wire information can be collected in time. By collecting the acoustic emission signals emitted by the acoustic emission sensors, the amplitude of the acoustic emission impact sensor output and the duration of the acoustic emission impact are input into the broken wire factor calculation formula for calculation, and then the broken wire factor evaluation criteria are used to evaluate the acoustic emission signals to obtain evaluation results. When the evaluation results meet the broken wire time conditions, an alarm message is generated. The present application achieves the technical effects of timely detecting broken wire conditions, accurately identifying broken wire signals, and improving the timeliness and accuracy of monitoring.

[0087] Embodiment 2

[0088] Based on the same inventive concept as the broken wire monitoring method based on acoustic emission technology in the aforementioned embodiment, Figure 6 As shown, the present application also provides a broken wire monitoring system based on acoustic emission technology, wherein the system comprises:

[0089] A sensor deployment module 11, the sensor deployment module 11 is used to determine sensor setting information based on basic information of the monitored cables and prestressed steel wires, and deploy acoustic emission sensors according to the sensor setting information;

[0090] An acoustic emission signal acquisition module 12, wherein the acoustic emission signal acquisition module 12 is used to collect the acoustic emission signal of the acoustic emission sensor, wherein the acoustic emission signal includes the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact;

[0091] A broken wire factor calculation module 13, the broken wire factor calculation module 13 is used to perform a broken wire factor calculation based on the amplitude of the output end of the acoustic emission impact sensor and the duration of the acoustic emission impact to obtain a broken wire factor calculation result;

[0092] An evaluation result obtaining module 14, wherein the evaluation result obtaining module 14 is used to evaluate the broken wire state according to the broken wire factor calculation result and the acoustic emission signal by using the broken wire factor evaluation criteria to obtain a broken wire evaluation result;

[0093] The alarm information generating module 15 is used to generate alarm information when the broken wire evaluation result meets the broken wire event condition.

[0094] Furthermore, the system also includes:

[0095] The broken wire factor calculation unit is used to calculate the broken wire factor according to the broken wire factor calculation formula: A broken wire factor calculation is performed to obtain the broken wire factor calculation result, wherein Q is the broken wire factor, A is the amplitude of the output end of the acoustic emission impact sensor, T is the duration of the acoustic emission impact, F is the broken wire force, Fr is the maximum broken wire force reference value, Ar is the amplitude of the sensor output end corresponding to the full scale of the equipment used, and Tr is the maximum duration of the broken wire impact.

[0096] Furthermore, the system also includes:

[0097] a non-broken wire signal obtaining unit, wherein the non-broken wire signal obtaining unit is used to obtain a non-broken wire signal when the broken wire factor calculation result Q is less than 0.1;

[0098] The broken wire signal obtaining unit is used for sending the alarm information when the broken wire factor calculation result Q is close to 1 as a broken wire signal.

[0099] Furthermore, the system also includes:

[0100] An AST test unit, wherein the AST test unit is used to perform an AST test on all deployed acoustic emission sensors, wherein the AST test is to use an acoustic emission device to automatically transmit pulse signals in turn, receive echo signals through the acoustic emission sensors, and determine the AST test results according to the received echo signals;

[0101] A wave velocity testing unit, wherein the wave velocity testing unit is used to perform a wave velocity test on the acoustic emission sensor, wherein the wave velocity test is applied between at least two of the acoustic emission sensors, and the sound velocity is calculated using the setting distance of the acoustic emission sensors, the time difference of receiving the impact excitation signal, and the impact position.

[0102] Furthermore, the system also includes:

[0103] A threshold setting unit, the threshold setting unit is used to set the threshold of each acoustic emission signal collection channel, and determine whether the acoustic emission signal of the current channel meets the threshold of the acoustic emission signal collection channel;

[0104] A signal acquisition unit, wherein the signal acquisition unit is used for not acquiring signals in a channel when the acoustic emission signal in the channel does not meet the threshold of the acoustic emission signal acquisition channel, and for acquiring the acoustic emission signal in the channel when the acoustic emission signal in the channel meets the threshold of the acoustic emission signal acquisition channel, and obtaining the signal basic parameter amplitude, signal frequency, count, signal duration, signal occurrence time, and signal arrival time to obtain the acoustic emission signal.

[0105] Furthermore, the system also includes:

[0106] A logic screening unit, the logic screening unit is used to screen the collected acoustic emission signals using intelligent logic judgment;

[0107] A frequency characteristic consistency unit, wherein the frequency characteristic consistency unit is used to make the frequency characteristic of the signal frequency consistent with the frequency characteristic of the acoustic emission sensor;

[0108] A signal attenuation satisfying unit, wherein the signal attenuation satisfying unit is used to ensure that the emission signals received by the plurality of acoustic emission sensors and the locations where the plurality of acoustic emission sensors are arranged satisfy the signal attenuation law;

[0109] A result distribution satisfying unit, wherein the result distribution satisfying unit is used to express the amplitude of the output end of the acoustic emission impact sensor in decibels and calculate the distribution of the wire breaking factor operation result Q value in volts to satisfy 0≤Q≤1;

[0110] A definition range satisfying unit is used to ensure that the arrival time of the acoustic emission signal received by each channel satisfies the event definition time range.

[0111] Furthermore, the system also includes:

[0112] A broken wire position determination unit, the broken wire position determination unit is used to determine the broken wire position according to the time difference of the acoustic emission signal obtained by each channel and the sound velocity obtained in the wave velocity test after evaluating the acoustic emission signal by using the broken wire factor evaluation criterion;

[0113] A wire breaking time determining unit, the wire breaking time determining unit is used to determine the wire breaking time according to the wire breaking position, the signal arrival time of the received acoustic emission signal, and the sound velocity;

[0114] a broken wire quantity determination unit, the broken wire quantity determination unit being used to determine the number of broken wires according to the counting information of the acoustic emission signal;

[0115] The broken wire evaluation result obtaining unit is used to obtain the broken wire evaluation result by using the broken wire position, broken wire time, broken wire quantity and broken wire factor calculation result.

[0116] Furthermore, the system also includes:

[0117] The basic information includes the monitored length, steel wire model, prestressing size, and key parts. When the key part is the main cable monitoring, the acoustic emission sensor is arranged along the main cable direction; when the key part is the inclined cable monitoring, the acoustic emission sensor is arranged along the inclined cable direction at the two anchor ends of the cable; when the key part is the suspension rod monitoring, the acoustic emission sensor is arranged along the suspension rod direction at the lower anchor end or the upper anchor end;

[0118] An impact test unit, the impact test unit is used to perform a center impact test on the monitored cable and prestressed steel wire to obtain a signal attenuation characteristic;

[0119] An interval information determination unit is used to determine sensor interval information according to the signal attenuation characteristic, wherein the maximum amplitude attenuation between two adjacent sensors is not greater than 30 dB.

[0120] Furthermore, the acoustic emission sensor has a built-in amplifier with an amplification factor of 6-60dB, a protection level of IP66, and an integrated AST pulse generation module.

[0121] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. Figure 1 The wire-broken monitoring method based on acoustic emission technology and the specific examples in the first embodiment are also applicable to the wire-broken monitoring system based on acoustic emission technology in the present embodiment. Through the above detailed description of the wire-broken monitoring method based on acoustic emission technology, those skilled in the art can clearly know the wire-broken monitoring system based on acoustic emission technology in the present embodiment, so for the sake of brevity of the specification, it will not be described in detail here. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description.

[0122] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A wire breakage monitoring method based on acoustic emission technology, characterized in that: The method comprises: Based on the basic information of the monitored cables and prestressed steel wires, the sensor setting information is determined, and the acoustic emission sensors are arranged according to the sensor setting information; Collecting an acoustic emission signal from the acoustic emission sensor, wherein the acoustic emission signal includes an amplitude of an output end of the acoustic emission impact sensor and a duration of the acoustic emission impact; Performing a broken wire factor calculation based on the amplitude of the output end of the acoustic emission impact sensor and the duration of the acoustic emission impact to obtain a broken wire factor calculation result; Using the broken wire factor evaluation criteria, evaluating the broken wire state according to the broken wire factor calculation result and the acoustic emission signal, to obtain a broken wire evaluation result; When the broken wire evaluation result meets the broken wire event condition, an alarm message is generated; The broken wire factor calculation is performed based on the amplitude of the output end of the acoustic emission impact sensor and the duration of the acoustic emission impact to obtain the broken wire factor calculation result, including: According to the broken wire factor calculation formula: Perform a broken wire factor calculation to obtain the broken wire factor calculation result, wherein Q is the broken wire factor, A is the amplitude of the acoustic emission impact sensor output end, T is the duration of the acoustic emission impact, F is the broken wire force, Fr is the maximum broken wire force reference value, Ar is the amplitude of the sensor output end corresponding to the full scale of the device used, and Tr is the maximum duration of the broken wire impact; Wherein, the determining of sensor setting information based on basic information of the monitored cables and prestressed steel wires, and the arranging of acoustic emission sensors according to the sensor setting information include: The basic information includes the monitored length, steel wire model, prestressing size, and key parts. When the key part is the main cable monitoring, the acoustic emission sensor is arranged along the main cable direction; when the key part is the inclined cable monitoring, the acoustic emission sensor is arranged along the inclined cable direction at the two anchor ends of the cable; when the key part is the suspension rod monitoring, the acoustic emission sensor is arranged along the suspension rod direction at the lower anchor end or the upper anchor end; Performing a center impact test on the monitored cables and prestressed steel wires to obtain signal attenuation characteristics; The sensor spacing information is determined according to the signal attenuation characteristic, wherein the maximum amplitude attenuation between two adjacent sensors is no greater than 30 dB.

2. The method according to claim 1, characterized in that When the broken wire evaluation result meets the broken wire event condition, generating alarm information includes: When the wire-breaking factor calculation result Q is less than 0.1, it is a non-wire-breaking signal; When the wire-breaking factor calculation result Q is close to 1, it is a wire-breaking signal, and the alarm information is sent.

3. The method according to claim 1, characterized in that The acoustic emission signal of the acoustic emission sensor is collected, which includes: Performing AST test on all deployed acoustic emission sensors, wherein the AST test is to use the acoustic emission equipment to automatically transmit pulse signals in turn, receive echo signals through the acoustic emission sensors, and determine the AST test results according to the received echo signals; A wave velocity test is performed on the acoustic emission sensor, wherein the wave velocity test is applied between at least two of the acoustic emission sensors, and the sound velocity is calculated using the setting distance of the acoustic emission sensors, the time difference of receiving the impact excitation signal, and the impact position.

4. The method according to claim 1, characterized in that Collecting the acoustic emission signal of the acoustic emission sensor includes: Set the threshold of each acoustic emission signal collection channel to determine whether the acoustic emission signal of the current channel meets the threshold of the acoustic emission signal collection channel; When the acoustic emission signal in the channel does not meet the threshold of the acoustic emission signal collection channel, the channel does not collect the signal. When the acoustic emission signal in the channel meets the threshold of the acoustic emission signal collection channel, the acoustic emission signal in the channel is collected to obtain the signal basic parameter amplitude, signal frequency, count, signal duration, signal occurrence time, and signal arrival time to obtain the acoustic emission signal.

5. The method according to claim 1, characterized in that The broken wire factor evaluation criteria include: Using intelligent logic judgment to screen the collected acoustic emission signals; According to the frequency characteristics of the signal frequency, it is consistent with the frequency characteristics of the acoustic emission sensor; The emission signals received by the multiple acoustic emission sensors and the locations where the multiple acoustic emission sensors are arranged satisfy the signal attenuation law; When the amplitude of the acoustic emission impact sensor output terminal is expressed in decibels, the distribution of the Q value of the broken wire factor calculation result calculated in volts satisfies 0≤Q≤1; The arrival time of the acoustic emission signal received by each channel meets the event definition time range.

6. The method according to claim 3, characterized in that Using the broken wire factor evaluation criteria, the broken wire state is evaluated according to the broken wire factor calculation result and the acoustic emission signal to obtain a broken wire evaluation result, including: After the acoustic emission signal is evaluated by using the broken wire factor evaluation criteria, the broken wire position is determined according to the time difference of the acoustic emission signal obtained by each channel and the sound velocity obtained in the wave velocity test; Determine the wire breaking time according to the wire breaking position, the signal arrival time of the acoustic emission signal received, and the sound velocity; Determining the number of broken wires according to the counting information of the acoustic emission signal; The broken wire evaluation result is obtained by using the calculation results of the broken wire position, the broken wire time, the broken wire quantity and the broken wire factor.

7. The method according to claim 1, characterized in that The acoustic emission sensor has a built-in amplifier with an amplification factor of 6-60dB, a protection level of IP66, and an integrated AST pulse generation module.

8. A wire breakage monitoring system based on acoustic emission technology, characterized in that: The system is used to implement a broken wire monitoring method based on acoustic emission technology as described in any one of claims 1 to 7, comprising: A sensor deployment module, the sensor deployment module is used to determine sensor setting information based on basic information of the monitored cables and prestressed steel wires, and deploy acoustic emission sensors according to the sensor setting information; An acoustic emission signal acquisition module, wherein the acoustic emission signal acquisition module is used to collect the acoustic emission signal of the acoustic emission sensor, wherein the acoustic emission signal includes the amplitude of the acoustic emission impact sensor output end and the duration of the acoustic emission impact; A broken wire factor calculation module, the broken wire factor calculation module is used to perform a broken wire factor calculation based on the amplitude of the output end of the acoustic emission impact sensor and the duration of the acoustic emission impact to obtain a broken wire factor calculation result; An evaluation result obtaining module, wherein the evaluation result obtaining module is used to evaluate the broken wire state according to the broken wire factor calculation result and the acoustic emission signal by using the broken wire factor evaluation criteria to obtain a broken wire evaluation result; An alarm information generation module is used to generate alarm information when the broken wire evaluation result meets the broken wire event condition.

Images