Fiber sensing and fiber channel fusion transmission system and method for dangerous building monitoring

Abstract

The application provides a fiber sensing and fiber channel fusion transmission system and method for monitoring dangerous buildings, which comprises stress sensing optical fibers which are arranged at positions vulnerable to damage on the periphery of buildings to be monitored; an integrated optical switch system which is located in a communication building and is used for monitoring different buildings to be monitored in different time periods, and comprises several levels of optical switch units, each of which comprises several optical switches, and the first level of optical switch units comprises one optical switch which is connected with a back transmission interface of a BOTDR instrument; a control unit, several building reserved communication optical fibers and the BOTDR instrument. The application uses the building reserved communication optical fibers to transmit sensing information and uses the integrated optical switch system and a particle swarm algorithm to realize purposeful monitoring of hundreds of dangerous buildings.

Description

Technical Field

[0001] This invention belongs to the fields of distributed optical fiber sensing and communication, and particularly relates to an optical fiber sensing and optical fiber channel integrated transmission system and method for monitoring dangerous buildings. Background Technology

[0002] Buildings are inextricably linked to our lives; we live and work within them. After a building is put into use, its structural function changes continuously due to factors such as load, disaster impacts, environmental erosion, material aging, and functional changes. This can lead to problems such as insufficient load-bearing capacity of components, excessively wide cracks, excessive deflection, overall tilting, and excessive uneven settlement. These issues pose immeasurable threats to personal safety, property security, the city's image, and social stability. Structural health monitoring of urban buildings helps to identify dangerous buildings in real time and provide early warnings, as well as a basis for subsequent maintenance and renovation. Many cities still have numerous buildings constructed in the 1950s and 60s that have long since become dangerous and pose constant safety hazards. Focusing on monitoring these dangerous buildings not only protects personal safety but also contributes to social stability. By monitoring the condition of dangerous buildings, we can determine whether they can continue to be used, avoiding blind reinforcement or demolition, thus improving resource utilization and preventing waste. Because dangerous buildings pose constant safety hazards, continuous measurement is necessary.

[0003] Fiber optic sensing technology involves wrapping an optical fiber around the building under test to monitor its deformation or temperature changes. However, dilapidated buildings in cities are generally far apart, making it impossible to measure all of them using a single fiber. Monitoring cost is a significant factor in monitoring projects; the cost of a single monitoring instrument is typically hundreds of thousands of yuan. If an instrument can only monitor one building, its practicality is greatly reduced. With the rapid development of technologies such as the internet, communication fiber optics, as the transmission medium, are now distributed like capillaries throughout cities. Using these reserved communication fibers to transmit sensing information can significantly reduce monitoring costs. Furthermore, to make full use of resources, the network provided by the telecommunications company can be used to send the monitoring and analysis results to a sensing app client, allowing relevant personnel to view the monitoring data in real time. This is of great significance for structural health monitoring of urban buildings. Moreover, the integration of communication and sensing promotes the practical application of next-generation optoelectronic information technology and next-generation communication technology, which is conducive to the rationalization of resources.

[0004] In addition, buildings can be categorized into key monitoring targets and non-key monitoring targets based on parameters such as their size, structural characteristics, construction time, location, and the importance of monitoring them. For key monitoring buildings, the monitoring time and frequency need to be increased to ensure their safety.

[0005] Distributed fiber optic sensing technology, as a promising structural health monitoring technology, is the ideal choice for continuous health measurement of dilapidated buildings. BOTDR instruments, as a typical distributed fiber optic sensing system, possess unique advantages such as simultaneous measurement of temperature and strain, long detection distance (up to hundreds of kilometers), and single-ended input, making them highly suitable for safety monitoring tasks in dilapidated buildings. Because sensor information can only be transmitted using optical fiber and there cannot be photoelectric conversion devices in the transmission path, it cannot directly share a channel with communication optical fiber. However, when deploying communication optical fiber, some reserved communication optical fibers are often laid simultaneously.

[0006] Based on the above analysis, this invention proposes a method for monitoring the safety of dilapidated buildings using BOTDR instruments by transmitting sensor information via pre-existing optical fiber in the building. This method, while saving costs, can simultaneously monitor the structural health of multiple dilapidated buildings, improving resource utilization. Furthermore, by utilizing the information storage and network transmission capabilities of telecommunications companies, building safety information can be sent to residents' mobile phones, ensuring residents' right to know and personal safety. Summary of the Invention

[0007] The purpose of this invention is to provide a fiber optic sensing and fiber optic channel integrated transmission system and method for monitoring dilapidated buildings. This system utilizes pre-existing communication optical fibers in the buildings to transmit sensor information and employs an integrated optical switch system and particle swarm optimization algorithm to achieve targeted monitoring of hundreds of dilapidated buildings. This method saves costs and improves resource utilization. To achieve the above objective, the following technical solution is adopted:

[0008] A fiber optic sensing and fiber optic channel fusion transmission system for monitoring dangerous buildings includes:

[0009] Several stress-sensing optical fibers are set up corresponding to several buildings to be monitored. Each stress-sensing optical fiber corresponds to one building to be monitored. The stress-sensing optical fibers are deployed at vulnerable locations on the periphery of the buildings to be monitored.

[0010] An integrated optical switch system, located inside a communications building, is used to monitor different buildings at different times. It consists of several levels of optical switch units. Each level of optical switch unit contains several optical switches, and each optical switch includes a front-end transmission interface and several back-end transmission interfaces.

[0011] The front transmission interface of the optical switch is connected to a rear transmission interface in the preceding optical switch unit, and each front transmission interface is configured to correspond to a rear transmission interface in the preceding optical switch unit.

[0012] Each rear transmission interface of the optical switch is connected to a front transmission interface in the next stage optical switch unit; each rear transmission interface is configured to correspond to a front transmission interface in the next stage optical switch unit.

[0013] The first-stage optical switch unit includes an optical switch for connection to the back-transmission interface of the BOTDR instrument.

[0014] The control unit is selectively connected to the control port of the optical switch to control the opening and closing of the optical switch, thereby enabling the monitoring of different buildings to be monitored.

[0015] Several buildings have reserved communication optical fibers. Each reserved communication optical fiber is set up with a corresponding stress sensing optical fiber. One end of the fiber is connected to the stress sensing optical fiber, and the other end is connected to a post-transmission interface in the last stage optical switch unit of the integrated optical switch system. The reserved communication optical fiber is placed in the corresponding building to be monitored, with the end of a section exposed to connect with the stress sensing optical fiber.

[0016] The BOTDR instrument, located inside the communications building, is used to provide detection pulse signals and acquire stress distribution maps of the building under monitoring. It is connected to the front transmission interface in the first-stage optical switch unit via optical fiber.

[0017] Preferably, it also includes a building overall status assessment model V(d) based on particle swarm optimization algorithm, wherein the building overall status assessment model V(d) classifies the input information of multiple buildings to be monitored and filters out the buildings that need to be monitored in a key manner and the buildings that are not monitored in a key manner;

[0018] The control unit receives the key monitoring building signal and sets the time interval for sending a shutdown signal to the integrated optical switch system. Then, it transmits the back-transmission port information corresponding to the key monitoring building signal to the integrated optical switch system to realize stress monitoring of different buildings for corresponding durations.

[0019] Preferably, the overall building condition assessment model V(d) is:

[0020] V(d)=ωv(d-1)+C1r1(pbe(d)-x(d))+C2r2(gva(d)-x(d));

[0021] Among them, C1 - the building's own condition factor, is set manually;

[0022] C2 - Social Conditions Factor of the Building, artificially set;

[0023] ω - Inertia factor, set manually;

[0024] r1 - building randomness coefficient one, r2 - building randomness coefficient two, both are set manually;

[0025] The values ​​of C1, C2, ω, r1, and r2 all range from 0.9 to 1.2.

[0026] ωv(d-1) - The aging rate of a building under the same environmental conditions;

[0027] C1r1(pbe(d)-x(d)) - The building's own condition;

[0028] C2r2(gva(d)-x(d)) - Social assessment of the building;

[0029] v(d-1), pbe(d), x(d), and gva(d) are all selected in the particle swarm algorithm.

[0030] Preferably, the integrated optical switch system includes a three-level optical switch unit; each optical switch includes eight back-transmission interfaces.

[0031] Preferably, it also includes: a sensing APP and a wireless transmission module, wherein the BOTDR instrument sends stress position signals to the cloud, and the sensing APP connects to the cloud through the wireless transmission module.

[0032] Preferably, the stress-sensing optical fiber is deployed in two ways: a four-sided arrangement and a wound arrangement; the four-sided arrangement is suitable for flat structures, and the wound arrangement is suitable for cylindrical structures.

[0033] A method for integrating fiber optic sensing and fiber optic channel transmission for monitoring dangerous buildings includes the following steps:

[0034] Step 1: Identify the vulnerable areas of the building;

[0035] Step 2: Lay out stress-sensing optical fibers in vulnerable locations;

[0036] Step 3: Build an integrated optical switch system. Determine the number of buildings to be monitored based on the number of back-transmission interfaces in the last stage of the integrated optical switch system.

[0037] Step 4: Measure the length L1 of the section of the pre-installed communication fiber optic cable in the building to be monitored, and the distance L2 from the pre-installed communication fiber optic cable in the building to the communication building.

[0038] Mark the stress-sensing fiber so that the length and layout of the stress-sensing fiber correspond to the building to be monitored.

[0039] Step 5: Connect the stress sensing fiber to the building's pre-installed communication fiber, and then connect the pre-installed communication fiber to the integrated optical switch system;

[0040] Step 6: Connect the optical switch system to the port of the BOTDR instrument;

[0041] Step 7: Turn on the BOTDR instrument and control unit. The control unit sends an activation command to the control port of any optical switch in the integrated optical switch system. At the same time, the BOTDR instrument emits a detection pulse signal, which is eventually transmitted to the stress sensing fiber. The BOTDR instrument receives the optical signal reflected from the stress sensing fiber and outputs a stress distribution map of the building to be monitored. The stress distribution map includes the stress location and stress magnitude.

[0042] Step 8: Based on the distance L from the stress location to the communication building in the stress distribution diagram, the length L1 of the section of the pre-installed communication fiber in the building to be monitored, and the distance L2 from the pre-installed communication fiber to the communication building, obtain the distance L3 = L-L1-L2 from the stress location to the end of the pre-installed communication fiber connected to the stress sensing fiber.

[0043] Preferably, step 8 further includes:

[0044] Step 8: Start the overall building status assessment model V(d), input the building information to be monitored into V(d), and V(d) will filter out the buildings that need to be monitored and the buildings that are not monitored.

[0045] The control unit then receives the signal from the key monitored building and sets the time interval for sending a shutdown signal to the integrated optical switch system. After that, it transmits the back-transmission port information corresponding to the key monitored building signal to the integrated optical switch system to realize stress monitoring of different buildings for different durations.

[0046] Compared with the prior art, the advantages of the present invention are as follows: after the stress sensing fiber is installed in the dangerous building, the stress sensing fiber is connected to the pre-reserved communication fiber in the building. The pre-reserved communication fiber in the building is used to transmit the sensing information, and the integrated optical switch system and particle swarm algorithm are used to realize the targeted monitoring of hundreds of dangerous buildings and to use the communication network to transmit the analysis results. Attached Figure Description

[0047] Figure 1 A structural diagram of a fiber optic sensing and fiber optic channel integrated transmission system for monitoring dangerous buildings;

[0048] Figure 2 Schematic diagram of an integrated optical switch system;

[0049] Figure 3 A schematic diagram of a four-sided stress sensing fiber optic deployment.

[0050] Figure 4 A schematic diagram of the layout of a wound stress sensing fiber optic cable;

[0051] Figure 5 Schematic diagram of the overall building condition assessment model V(d);

[0052] Figure 6 Filter building flowcharts for the overall building status assessment model V(d);

[0053] Figure 7 This diagram illustrates the communication principle between the control unit, the overall building status assessment model, the integrated optical switch system, and the BOTDR instrument.

[0054] Among them, 1-BOTDR instrument, 2-Communication building, 3-Integrated optical switch system, 31-First-level optical switch unit, 32-Optical switch, 4-Building reserved communication optical fiber, 5-Building to be monitored, 6-Stress sensing optical fiber, 7-Cloud, 8-Wireless transmission module, 9-Sensing APP, 10-Control unit, 11-Building overall status assessment model. Detailed Implementation

[0055] The fiber optic sensing and fiber optic channel fusion transmission system and method for monitoring dangerous buildings according to the present invention will be described in more detail below with reference to the schematic diagrams, which illustrate preferred embodiments of the present invention. It should be understood that those skilled in the art can modify the present invention described herein while still achieving the advantageous effects of the present invention. Therefore, the following description should be understood as being of general knowledge to those skilled in the art and is not intended to limit the present invention.

[0056] The presence of numerous dilapidated buildings in the city, scattered across various locations, increases the difficulty and cost of monitoring these buildings. Figures 1-7 As shown, a fiber optic sensing and fiber optic channel integrated transmission system for monitoring dilapidated buildings is proposed. This system utilizes pre-existing communication fibers in the buildings to transmit sensor information and employs an integrated optical switch system and particle swarm optimization algorithm to simultaneously and purposefully monitor hundreds of dilapidated buildings. The analysis results are then transmitted via a communication network. This method can significantly reduce monitoring and labor costs and improve resource utilization.

[0057] Specifically, it includes:

[0058] Several stress-sensing optical fibers 6 are set up corresponding to several buildings 5 ​​to be monitored. Each stress-sensing optical fiber 6 corresponds to one building 5 to be monitored. In order to carry out safety monitoring of dangerous buildings (buildings to be monitored), the stress-sensing optical fibers 6 need to be deployed in vulnerable positions (critical positions that are prone to deformation) on the periphery of the buildings to be monitored 5.

[0059] The stress sensing fiber optic cable 6 can be deployed in two ways: four-sided and wrapped. The four-sided method is suitable for flat structures, while the wrapped method is suitable for cylindrical structures. Figure 3 This deployment method can be used for relatively flat structures such as load-bearing walls, allowing for comprehensive wall safety monitoring while saving on fiber optic cables. Figure 4The winding method can be used for cylindrical structures such as load-bearing columns or to wrap around the entire building, providing comprehensive monitoring of the building's exterior. The number of buildings to be monitored can range from 50 to 1000.

[0060] The integrated optical switch system 3, located within the communication building 2, is used to monitor different buildings 5 ​​at different times. Since the buildings age relatively slowly, they only need to be monitored once or twice a day, with each monitoring session lasting 2 minutes. The number of buildings monitored can be determined based on the number of interfaces on the integrated optical switch system. This allows one BOTDR instrument 1 to simultaneously monitor multiple buildings, significantly improving efficiency and reducing costs.

[0061] The integrated optical switch system 3 includes several levels of optical switch units. Each level of optical switch unit contains several optical switches 32. Each optical switch 32 includes a front transmission interface and several rear transmission interfaces.

[0062] The front transmission interface of the optical switch 32 is connected to a rear transmission interface in the preceding optical switch unit, and each front transmission interface is configured to correspond to a rear transmission interface in the preceding optical switch unit.

[0063] Each rear transmission interface of the optical switch 32 is connected to a front transmission interface in the next stage optical switch unit; each rear transmission interface is configured to correspond to a front transmission interface in the next stage optical switch unit.

[0064] The first-level optical switch unit 31 includes an optical switch 32 for connection to the back-end transmission interface of the BOTDR instrument 1. The model of the optical switch can be determined according to the number of buildings to be monitored. Figure 2 As shown, a cascaded three-layer (8×8×8) system can simultaneously monitor the safety of 512 dilapidated buildings.

[0065] Furthermore, the integrated optical switch system 3 includes three levels of optical switch units; each optical switch 32 includes eight back-transmission interfaces.

[0066] Several buildings have pre-installed communication optical fibers 4, each corresponding to a stress-sensing optical fiber 6. One end of the pre-installed communication optical fiber 4 is connected to the stress-sensing optical fiber 6, and the other end is connected to a post-transmission interface in the last stage optical switch unit of the integrated optical switch system 3. A section of the pre-installed communication optical fiber 4 is placed inside the corresponding building 5 to be monitored, with its end exposed for connection to the stress-sensing optical fiber 6. Both the integrated optical switch system 3 and the pre-installed communication optical fiber 4, and the BOTDR instrument 1 and the integrated optical switch system 3, involve bidirectional optical signal transmission.

[0067] BOTDR instrument 1, located in communication building 2, is used to provide detection pulse signals and acquire stress distribution maps corresponding to the building 5 to be monitored. It is connected to the front-end transmission interface in the first-stage optical switch unit 31 via optical fiber. Since the stress sensing fiber 6 required for sensing by BOTDR instrument 1 is the same type of fiber as the pre-installed communication fiber 4 in the building, the data in the stress sensing fiber 6 can be directly transmitted from the pre-installed communication fiber 4 in the building to BOTDR instrument 1 in communication building 2 for analysis.

[0068] As known from existing technology, the working principle of BOTDR instrument 1 is as follows: When pump light is incident into an optical fiber, three types of scattering occur due to optical effects: Rayleigh scattering, Brillouin scattering, and Raman scattering. Brillouin scattering includes spontaneous Brillouin scattering and stimulated Brillouin scattering. When the input light power is low, spontaneous acoustic fields are generated in the fiber due to molecular thermal motion. These acoustic fields generate refractive index gratings in the fiber with the same direction and velocity as the acoustic waves. When the incident light encounters the refractive index grating, it is reflected, i.e., spontaneous Brillouin scattering. Due to the Doppler effect, the scattered light has a certain frequency shift (approximately 10.8 GHz) compared to the incident light. The light with the increased frequency is called anti-Stokes light, and the light with the decreased frequency is called Stokes light. When the optical fiber is subjected to stress and deforms, or when the temperature of the fiber changes, the frequencies of the Brillouin-Stokes and anti-Stokes lights change. By demodulating the frequency shifts of the Stokes or anti-Stokes lights before and after the temperature or stress change, the magnitude of the change in external temperature or stress can be obtained.

[0069] When a narrow probe pulse is injected into an optical fiber, it continuously generates Stokes light propagating in the opposite direction during transmission. This Stokes light is transmitted through the optical fiber to the photodetector. If the pulse is emitted from the beginning of the optical fiber, the time required for the photodetector to receive the Stokes light generated at position L is t. During this time interval t, the light travels back and forth from the beginning to position L. Therefore, the length L from the beginning to position L can be expressed as L = ct / 2n.

[0070] Where c is the speed of light and n is the refractive index of the optical fiber. Based on the above formula, accurate positioning can be achieved by determining the time required to receive the reflected light.

[0071] Furthermore, a building overall status assessment model 11 (V(d)) based on particle swarm optimization algorithm is established. The information of multiple buildings to be monitored 5 (C1, C2, ω, r1, r2) is classified and the buildings that need to be monitored and the buildings that do not need to be monitored are selected.

[0072] Extinction ratio (ER) is a crucial parameter in BOTDR instruments, measuring the instrument's ability to block continuous light from the substrate. The magnitude of the extinction ratio affects the system's signal-to-noise ratio, thus impacting sensing distance and measurement accuracy. A low extinction ratio results in more continuous light leaking from the substrate, which enters the fiber and causes Brillouin scattering interference pulses, thus affecting system performance. It is defined as the ratio of the pulse's peak power to the substrate power, as shown in the following formula:

[0073] Where P p P is the peak power of the pulse. b This represents the pulse base power.

[0074] Currently, the modulator used inside most BOTDR instruments is an EOM (electro-optic modulator), with an extinction ratio of around 30dB. To achieve better sensing performance, the modulation depth needs to be increased. Therefore, an SOA (semiconductor optical amplifier) ​​can be used for modulation, with an extinction ratio generally higher than 40dB.

[0075] Particle Swarm Optimization (PSO) is an evolutionary computational technique based on avian foraging. Invented by electrical engineer Dr. Eberhart and American social psychologist Dr. Kennedy, it is an iterative optimization tool. The basic idea of ​​this algorithm is to find the optimal solution through cooperation and information sharing among individuals within a swarm.

[0076] To distinguish between key monitoring targets and non-key monitoring targets, the particle swarm optimization algorithm is used to classify buildings.

[0077] The overall building condition assessment model 11V(d) equals the aging rate + the building's own condition + the social assessment of the building, i.e.

[0078] V(d)=ωv(d-1)+C1r1(pbe(d)-x(d))+C2r2(gva(d)-x(d)).

[0079] Among them, C1 - the building's own condition factor, including size, structural characteristics, construction time, whether a disaster has occurred, etc., is set artificially. The larger this factor is, the more the monitor attaches importance to the building's own condition.

[0080] C2 - Social Status Factor of the Building, including location, population density, etc., is set artificially. The larger this factor is, the better the location of the building and the higher its social status.

[0081] ω-Inertia Factor, an artificially set value, indicates that the building is in a more stable environment and is less prone to accelerated aging.

[0082] r1 - building randomness coefficient one, r2 - building randomness coefficient two, are both set manually to indicate that the building has randomness.

[0083] The values ​​of C1, C2, ω, r1, and r2 all range from 0.9 to 1.2. If a certain parameter of the building needs to be given special consideration, the weight of that parameter can be appropriately increased.

[0084] ωv(d-1) - The aging rate of a building under the same environment.

[0085] C1r1(pbe(d)-x(d)) - The building's own condition.

[0086] C2r2(gva(d)-x(d)) - Social assessment of the building.

[0087] v(d-1), pbe(d), x(d), and gva(d) are all selected in the particle swarm algorithm.

[0088] like Figure 6 As shown, the program first inputs various building parameters, such as condition factors, including size, structural features, construction time, whether a disaster has occurred, location, and population density. After parameter settings are complete, the program automatically calculates the monitoring value of each building and allocates monitoring time according to the calculated monitoring value, allocating more monitoring time and frequency to buildings requiring priority monitoring. Furthermore, the building status needs to be updated periodically (every six months, once a year, or after a disaster) to ensure that the most critical buildings are selected for monitoring. If the calculated results meet expectations, monitoring is executed; otherwise, the parameters are re-entered until expectations are met.

[0089] The control unit 10 is selectively connected to the control port of the optical switch 32 to control the opening and closing of the optical switch, thereby enabling monitoring of different buildings 5 ​​to be monitored. For key buildings, the integrated optical switch system 3 can be used to increase the monitoring time and frequency to ensure their safety. Specifically, the number of measurements can be set manually or by software. If it is desired to monitor a building at different times (morning, afternoon, evening, etc.), or if it is inconvenient to measure a building for an extended period, multiple short-duration measurements can be used.

[0090] Furthermore, such as Figure 7As shown, the control unit 10 receives the key monitoring building signal (electrical signal) and sets the time interval for sending a shutdown signal to the integrated optical switch system 3. Then, it transmits the back-transmission port information corresponding to the key monitoring building signal to the integrated optical switch system 3 to achieve stress monitoring of different buildings 5 ​​for corresponding durations. Specifically, if a building has experienced disasters such as fire or earthquake, its condition can be manually adjusted in the program. The building assessment system will comprehensively compare the conditions of other buildings to be monitored and reasonably allocate the monitoring time. Control commands are used to control the on / off state of the switches within the integrated optical switch system to achieve stress monitoring of the building for the corresponding duration.

[0091] Therefore, a single BOTDR instrument 1 can simultaneously monitor multiple buildings in a targeted manner, providing comprehensive monitoring of the building conditions. This greatly improves monitoring efficiency, reduces costs, and ensures the safety of people inside and around the buildings, resulting in significant economic and social benefits.

[0092] To facilitate access to monitoring results, a customized sensor app is needed. Data analyzed by the BOTDR instrument will be sent to the app via a communication network. Residents can download the app to easily monitor the safety status of their homes, achieving truly comprehensive monitoring at all times. Specifically, a sensor app 9 and a wireless transmission module 8 will be set up. The BOTDR instrument 1 will send stress location signals to the cloud 7, and the sensor app 9 will connect to the cloud 7 via the wireless transmission module 8.

[0093] This method is not limited to monitoring dilapidated buildings; it can be used to monitor any facility with pre-installed fiber optic communication.

[0094] A fiber optic sensing and fiber optic channel fusion transmission method for monitoring dangerous buildings includes the following steps:

[0095] Step 1: Identify vulnerable areas of the building. Relevant engineering personnel need to assess the building's safety and locate vulnerable areas before fiber optic cable installation.

[0096] Step 2: Lay out stress-sensing optical fibers 6 at locations prone to damage.

[0097] Step 3: Build an integrated optical switch system 3. Determine the number of buildings 5 ​​to be monitored based on the number of back-transmission interfaces of the last stage of the integrated optical switch system 3.

[0098] Step 4: Measure the length L1 of the section of the pre-installed communication fiber optic cable 4 in the building 5 to be monitored, and the distance L2 from the pre-installed communication fiber optic cable 4 to the communication building 2.

[0099] Mark the stress sensing fiber 6 so that the length and layout of the stress sensing fiber 6 correspond to the building 5 to be monitored.

[0100] Step 5: Connect the stress sensing fiber optic cable 6 to the building's pre-installed communication fiber optic cable 4, and then connect the pre-installed communication fiber optic cable to the integrated optical switch system 3.

[0101] Step 6: Connect the optical switch 32 system to the port of BOTDR instrument 1.

[0102] Step 7: Turn on the BOTDR instrument 1 and the control unit 10. The control unit 10 sends an activation command to the control terminal of any optical switch in the integrated optical switch system 3 (the control unit 10 sends an activation command to the integrated optical switch system, causing the integrated optical switch system to open a specific monitoring path); the control unit 10 is connected to the optical switch control port to control the on / off state of each optical switch.

[0103] Simultaneously, BOTDR instrument 1 emits a detection pulse signal, which is eventually transmitted to stress sensing fiber 6. BOTDR instrument 1 receives the light signal reflected from stress sensing fiber 6 and outputs the stress distribution map corresponding to the building 5 to be monitored. The stress distribution map includes the stress location and stress magnitude.

[0104] Therefore, the integrated optical switch system is used to control which dangerous building BOTDR instrument 1 monitors at which time period.

[0105] Step 8: Based on the distance L from the stress location to the communication building 2 in the stress distribution diagram, i.e. the distance between the stress location and the subsequent transmission interface, the length L1 of the section of the reserved communication fiber 4 in the building to be monitored 5, and the distance L2 from the reserved communication fiber 4 to the communication building 2, obtain the distance L3 from the stress location to the end of the stress sensing fiber 6 connected to the reserved communication fiber 4 in the building.

[0106] Step 8 also includes:

[0107] Start the overall building status assessment model 11V(d), input the information of the building to be monitored 5 into V(d), and V(d) filters out the buildings that need to be monitored and the buildings that are not monitored.

[0108] Afterwards, the control unit 10 receives the key monitoring building signal and sets the time interval for sending a shutdown signal to the integrated optical switch system 3. Then, it transmits the back-transmission port information corresponding to the key monitoring building signal to the integrated optical switch system 3 to realize the corresponding duration stress monitoring of different buildings 5 ​​to be monitored.

[0109] Step 9: Save the monitored data to the cloud in chronological order for easy viewing and analysis. Send the sensor results to the APP in real time so residents can be informed of the building's status. The APP is also equipped with an alarm system that automatically sounds an alarm when the deformation exceeds the normal value, reminding residents to take timely measures to ensure their safety.

[0110] The above are merely preferred embodiments of the present invention and do not constitute any limitation on the present invention. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and content disclosed in the present invention without departing from the scope of the present invention shall be deemed to have remained within the protection scope of the present invention.

Claims

1. A fiber sensing and fiber channel fusion transmission system for dangerous building monitoring, characterized in that, include: Several stress-sensing optical fibers are set up corresponding to several buildings to be monitored. Each stress-sensing optical fiber corresponds to one building to be monitored. The stress-sensing optical fibers are deployed at vulnerable locations on the periphery of the buildings to be monitored. An integrated optical switch system, located inside a communications building, is used to monitor different buildings at different times. It consists of several levels of optical switch units. Each level of optical switch unit contains several optical switches, and each optical switch includes a front-end transmission interface and several back-end transmission interfaces. The front transmission interface of the optical switch is connected to a rear transmission interface in the preceding optical switch unit, and each front transmission interface is configured to correspond to a rear transmission interface in the preceding optical switch unit. Each rear transmission interface of the optical switch is connected to a front transmission interface in the next stage optical switch unit; each rear transmission interface is configured to correspond to a front transmission interface in the next stage optical switch unit. The first-stage optical switch unit includes an optical switch for connection to the back-transmission interface of the BOTDR instrument. The control unit is selectively connected to the control port of the optical switch to control the opening and closing of the optical switch, thereby enabling the monitoring of different buildings to be monitored. Several buildings have reserved communication optical fibers. Each reserved communication optical fiber is set up with a corresponding stress sensing optical fiber. One end of the fiber is connected to the stress sensing optical fiber, and the other end is connected to a post-transmission interface in the last stage optical switch unit of the integrated optical switch system. The reserved communication optical fiber is placed in the corresponding building to be monitored, with the end of a section exposed to connect with the stress sensing optical fiber. The BOTDR instrument, located inside the communications building, is used to provide detection pulse signals and acquire stress distribution maps of the building under monitoring. It is connected to the front transmission interface in the first-stage optical switch unit via optical fiber.

2. The fiber optic sensing and fiber optic channel fusion transmission system for monitoring dangerous buildings according to claim 1, characterized in that, It also includes a building overall condition assessment model based on the particle swarm optimization algorithm. V(d) The building overall condition assessment model V (d) The input information on multiple buildings to be monitored is categorized, and buildings that require key monitoring and those that are not are filtered out. The control unit receives the key monitoring building signal and sets the time interval for sending a shutdown signal to the integrated optical switch system. Then, it transmits the back-transmission port information corresponding to the key monitoring building signal to the integrated optical switch system to realize stress monitoring of different buildings for corresponding durations.

3. The fiber optic sensing and fiber optic channel fusion transmission system for monitoring dangerous buildings according to claim 2, characterized in that, The overall building condition assessment model V(d) for: V(d) = v(d-1)+ (pbe(d)-x(d))+ (gva(d)-x(d)) ； in, - Factors related to the building's own condition, which are artificially set; -Social factors affecting the building's condition are artificially set; - Inertia factor, set manually; -Randomness coefficient of the building is one. - The randomness coefficient of the building is two, and both are set manually; , , , , The values ​​range for all values ​​are 0.9 to 1.

2. v(d-1) - The rate at which buildings age under the same conditions; (pbe(d)-x(d)) -The building's own condition; (gva(d)-x(d)) -Social assessment of the building; v(d-1), pbe(d), x(d), gva(d) All were selected from the particle swarm optimization algorithm.

4. The fiber optic sensing and fiber optic channel fusion transmission system for monitoring dangerous buildings according to claim 1, characterized in that, The integrated optical switch system includes three levels of optical switch units; each optical switch includes eight back-transmission interfaces.

5. The fiber optic sensing and fiber optic channel fusion transmission system for monitoring dangerous buildings according to claim 1, characterized in that, Also includes: The BOTDR instrument transmits stress location signals to the cloud, and the sensing app connects to the cloud via the wireless transmission module.

6. The fiber optic sensing and fiber optic channel fusion transmission system for monitoring dangerous buildings according to claim 1, characterized in that, The stress-sensing optical fiber can be deployed in two ways: a four-sided layout and a wound layout. The four-sided layout is suitable for flat structures, while the wound layout is suitable for cylindrical structures.

7. A method for integrating fiber optic sensing and fiber optic channel transmission for monitoring dangerous buildings, characterized in that, Includes the following steps: Step 1: Identify the vulnerable areas of the building; Step 2: Lay out stress-sensing optical fibers in vulnerable locations; Step 3: Build an integrated optical switch system. Determine the number of buildings to be monitored based on the number of back-transmission interfaces in the last stage of the integrated optical switch system. Step 4: Measure the length L1 of the section of the pre-installed communication fiber optic cable in the building to be monitored, and the distance L2 from the pre-installed communication fiber optic cable in the building to the communication building. Mark the stress-sensing fiber so that the length and layout of the stress-sensing fiber correspond to the building to be monitored. Step 5: Connect the stress sensing fiber to the building's pre-installed communication fiber, and then connect the pre-installed communication fiber to the integrated optical switch system; Step 6: Connect the optical switch system to the port of the BOTDR instrument; Step 7: Turn on the BOTDR instrument and control unit. The control unit sends an activation command to the control port of any optical switch in the integrated optical switch system. At the same time, the BOTDR instrument emits a detection pulse signal, which is eventually transmitted to the stress sensing fiber. The BOTDR instrument receives the light signal reflected from the stress sensing fiber and outputs the stress distribution map corresponding to the building to be monitored. The stress distribution map includes the stress location and stress magnitude. Step 8: Based on the distance L from the stress location to the communication building in the stress distribution diagram, the length L1 of the section of the pre-installed communication fiber in the building to be monitored, and the distance L2 from the pre-installed communication fiber to the communication building, obtain the distance L3 from the stress location to the end of the pre-installed communication fiber connected to the stress sensing fiber in the building.

8. The fiber optic sensing and fiber optic channel fusion transmission method for monitoring dangerous buildings according to claim 7, characterized in that, Step 8 also includes: Step 8: Activate the overall building condition assessment model V(d) Input the information of the building to be monitored into the system. V(d) , V(d) The buildings that require key monitoring and those that are not are selected for monitoring. The control unit then receives the signal from the key monitored building and sets the time interval for sending a shutdown signal to the integrated optical switch system. After that, it transmits the back-transmission port information corresponding to the key monitored building signal to the integrated optical switch system to realize stress monitoring of different buildings for different durations.

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