A comprehensive monitoring system for granary environmental safety based on fiber grating and distributed optical fiber technology

Abstract

The present invention provides a comprehensive monitoring system for granary environmental safety based on fiber grating and distributed optical fiber technology, and relates to the technical field of granary monitoring. The present invention uses a set of distributed optical fiber sensing technology to achieve measurement of three parameters: vibration, strain, and temperature, and uses a set of optical fiber grating sensing technology to achieve simultaneous detection of humidity and carbon dioxide gas concentration. A granary environmental early warning coefficient reflecting the risk state of the granary is generated through comprehensive analysis of vibration, strain, temperature, humidity, and carbon dioxide gas concentration. The granary safety is warned through the granary environmental early warning coefficient. The present invention can achieve efficient and accurate collection of granary environmental data, and can also predict food storage risks through the granary environmental early warning coefficient.

Description

Technical Field

[0001] The present invention relates to the technical field of granary monitoring, and in particular to a granary environmental safety comprehensive monitoring system based on fiber grating and distributed optical fiber technology. Background Art

[0002] As the foundation of human survival and development, food has played a vital role since ancient times. Food is not only the cornerstone of the national economy, but also the basic guarantee of people's lives. Food production has obvious seasonality, while consumption is all year round. Proper food storage can balance the seasonal differences in production and consumption and ensure the stability of food supply.

[0003] In modern agriculture and grain storage management, granary environmental monitoring is an important part of ensuring food safety and quality. Traditional monitoring methods usually rely on decentralized, localized sensor systems, which can only provide information within a limited range and cannot fully cover the entire granary. In addition, these traditional sensors may face stability and accuracy issues in long-term operation, resulting in unreliable monitoring data. The complex and changeable environmental factors inside the granary, such as temperature, humidity, vibration, and carbon dioxide concentration, may affect the quality of stored grain, thereby increasing the risk of grain damage. Faced with these challenges, how to build an efficient, accurate, and real-time monitoring system has become a technical problem that needs to be solved in granary environmental management.

[0004] In order to deal with the above problems, the application of fiber Bragg grating and distributed optical fiber technology in granary monitoring has gradually attracted attention. Fiber optic technology has become an ideal solution for comprehensive and real-time monitoring due to its high sensitivity, anti-electromagnetic interference ability and long-distance transmission advantages. By comprehensively utilizing fiber Bragg grating and distributed optical fiber technology, the coverage and data accuracy of the environmental monitoring system can be effectively improved, and it can operate stably under a variety of complex environmental conditions, thus meeting the high standards of environmental monitoring in modern granary management.

[0005] In the prior art, the publication number CN115902117A discloses a method, system, terminal and medium for monitoring the environment of a grain silo, including: obtaining detection data at detection points at different positions in a grain pile, the detection data including a carbon dioxide detection value and a temperature detection value; in response to the carbon dioxide detection value being greater than a preset carbon dioxide threshold or / and the temperature detection value being greater than a preset temperature threshold, determining that the detection data is abnormal and generating an abnormal signal; based on the abnormal signal, obtaining the detection point where the abnormal signal occurs to determine that an abnormality occurs. This prior art can improve the rapid positioning of the position where an abnormal change occurs in a grain pile, and improve the accuracy of abnormal change detection, but this prior art still has defects. This prior art uses conventional sensors to detect the temperature and carbon dioxide concentration in the grain silo, with few detection parameters and low measurement accuracy, and cannot accurately determine the abnormal state of the grain silo. In addition, the two types of data are analyzed separately, ignoring the connection between the data, which will result in unconvincing analysis results.

[0006] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not constitute the prior art that is already known to one of ordinary skill in the art. Summary of the invention

[0007] The purpose of the present invention is to provide a comprehensive monitoring system for granary environmental safety based on fiber grating and distributed optical fiber technology to solve the problems raised in the above background technology.

[0008] To achieve the above object, the present invention provides the following technical solutions:

[0009] A comprehensive monitoring system for granary environmental safety based on fiber grating and distributed optical fiber technology, specifically including:

[0010] The data acquisition module is used to divide the granary into N areas, collect the granary environmental data of each area, and convert the collected granary environmental data from optical signals to electrical signals; the granary environmental data includes grain strain data, granary temperature data, vibration amplitude time series data, granary humidity data and carbon dioxide concentration data; the strain data is the height of the grain;

[0011] Data analysis module, used to analyze and process the electrical signals of granary environmental data;

[0012] The result display module is used to display and warn the analysis and processing results of the electrical signals of the granary environmental data.

[0013] Furthermore, the data acquisition module includes an optical fiber acquisition unit and an optical fiber Bragg grating acquisition unit. The optical fiber acquisition unit is used to collect grain strain data, granary temperature data and vibration amplitude time series data; the optical fiber Bragg grating acquisition unit is used to collect granary humidity data and carbon dioxide concentration data.

[0014] Further, the optical fiber acquisition unit includes a temperature optical fiber sensor, a vibration optical fiber sensor, a strain optical fiber sensor, a 1550nm narrow linewidth laser, an acousto-optic modulator, erbium-doped fiber amplifiers EDFA 1 and EDFA 2, a circulator, an optical sensing fiber, a wavelength division multiplexer, three photodetectors, a Raman scattering temperature compensation system and a data acquisition card;

[0015] The narrow linewidth laser emits a continuous light wave, which is chopped into pulses by the acousto-optic modulator, amplified by EDFA 1, and then injected into the temperature fiber sensor, the vibration fiber sensor and the strain fiber sensor through a circulator, and the backscattered light from the temperature fiber sensor, the vibration fiber sensor and the strain fiber sensor is input into the wavelength division multiplexer, where the light is divided into four beams of Brillouin, Rayleigh, Stokes and anti-Stokes, the Brillouin scattering signal reflects the temperature data, the Brillouin scattering signal is detected by the photodetector 1, the Stokes and anti-Stokes scattering signals reflect the strain data, which are detected by the dual-channel photodetector 2, the Rayleigh scattering signal reflects the vibration data, which is amplified by EDFA 2 and detected by the photodetector 3, the photodetector is used to convert the optical signal into an electrical signal, and in addition, a Raman scattering temperature compensation system is designed after the photodetector 1 and the photodetector 2 to eliminate the frequency change caused by the temperature data and the strain data during Brillouin scattering. Further, the fiber grating acquisition unit includes a fiber grating carbon dioxide sensor, a fiber grating humidity sensor, a 1550nm narrow linewidth laser, a circulator, a wavelength division multiplexer and a data acquisition card;

[0016] The narrow linewidth laser emits a continuous light wave, which is incident light into the fiber Bragg grating carbon dioxide sensor and the fiber Bragg grating humidity sensor through a circulator. When the incident light enters the optical fiber, the grating area will reflect a part of the incident light. Finally, all the light that meets the Bragg condition will be superimposed into a reflection peak. The change data of the central wavelength of the reflected light peak is detected by the spectrum analyzer, and the change amount of the parameter to be detected can be calculated. The specific logic for satisfying the Bragg condition is that the wavelength of the incident light is equal to the Bragg wavelength, and the specific formula for obtaining the Bragg wavelength is:

[0017] λ B =2n eff Λ

[0018] Among them, λ B is the Bragg wavelength, n effis the effective refractive index of the grating, and Λ is the period of the grating.

[0019] Furthermore, the specific logic for analyzing and processing the electrical signal of the granary environmental data is as follows: obtaining the historical granary environmental data and the granary environmental data of each area, extracting abnormal features from the granary environmental data of each area to obtain the granary abnormal feature data, obtaining the risk weights of temperature, height, vibration, humidity and carbon dioxide concentration according to the historical warning conditions, weighting and normalizing the granary abnormal feature data according to the risk weights, and analyzing the weighted and normalized granary abnormal feature data to obtain the granary status index;

[0020] The specific formula used to obtain the risk weights for temperature, grain height, vibration, humidity and carbon dioxide concentration is:

[0021]

[0022] Among them, α i is the risk weight coefficient of the i-th granary environmental data, N is the number of historical granary environmental warnings, and n i is the number of warnings caused by abnormal granary environmental data of the i-th type, i is the index of the type of granary environmental data, and i∈[1,5];

[0023] The specific formula for weighted normalization of the abnormal characteristic data of granaries in each area is:

[0024]

[0025] Among them, X′ i is the normalized abnormal characteristic data of the i-th granary, X i is the abnormal characteristic data of the i-th granary, X imin is the minimum value of the abnormal characteristic data of the i-th granary, x imax is the maximum value of the abnormal characteristic data of the i-th granary.

[0026] Furthermore, the specific logic for extracting abnormal features from granary environmental data is as follows: the granary temperature data, granary humidity data and carbon dioxide concentration data are processed to obtain temperature abnormality data, humidity abnormality data and carbon dioxide concentration data; the vibration amplitude time series data is Fourier transformed to transform the vibration data into the form of the sum of a series of complex numbers; the amplitude of each frequency in the frequency range of 0-100 kHz is summed to obtain vibration abnormality data; the specific formula for obtaining temperature abnormality data is as follows:

[0027]

[0028] Among them, T Y is the abnormal temperature, T is the granary temperature in the granary area, and Tmax is the standard maximum temperature, T min is the standard minimum temperature;

[0029] The specific formula for obtaining humidity anomaly data is:

[0030]

[0031] Among them, W Y is the abnormal humidity, W is the granary humidity in the granary area, and W max is the standard maximum humidity, W min is the standard minimum humidity;

[0032] The specific formula for obtaining carbon dioxide concentration data is:

[0033]

[0034] Among them, CO Y is the abnormal carbon dioxide concentration, CO is the carbon dioxide concentration in the granary area, and CO max is the standard maximum carbon dioxide concentration, CO min is the standard minimum carbon dioxide concentration;

[0035] The vibration abnormality data includes harmful frequency number, harmful amplitude and harmful frequency number, the harmful frequency number is the total number of frequencies between 0-100kHz, and the specific formula for obtaining the harmful amplitude and harmful frequency number is:

[0036]

[0037] Among them, P is the harmful amplitude and M is the harmful frequency, F is f is the amplitude of the fth harmful frequency, and f is the harmful frequency index.

[0038] Furthermore, the specific logic for obtaining the granary status index is as follows: abnormal vibration data, abnormal temperature data, abnormal humidity data and carbon dioxide concentration data are analyzed to generate a granary environmental warning coefficient, and the granary environmental warning coefficient of each area is statistically analyzed to obtain the granary status index; the specific formula for generating the granary environmental warning coefficient is as follows:

[0039]

[0040] Among them, T Y is the abnormal temperature, W Y Abnormal humidity, CO Y is the abnormal carbon dioxide concentration, P is the harmful amplitude and, M is the harmful frequency, Ad is the granary environmental warning coefficient of the corresponding area;

[0041] The specific formula for obtaining the granary status index is as follows:

[0042]

[0043] Among them, Ae is the granary status index, and Ad j is the granary environment warning coefficient of the j-th area, and Ad' is the median of the granary environment warning coefficients. N is the number of granary areas, and j is the granary area index.

[0044] The result display module is divided into a result display unit and a risk warning unit. The results displayed by the result display unit are: the temperature, grain height, vibration, humidity, and carbon dioxide concentration of the granary; the specific logic for the risk warning unit to give a warning is: when the granary status index is in the range of 0 < Ae ≤ 0.3, it indicates that the granary is in a low-risk state and the environment is safe; when the granary status index is in the range of 0.3 < Ae ≤ 0.7, it indicates that the granary is in a medium-risk state, and monitoring and adjustment are required; when the granary status index is in the range of 0.7 < Ae ≤ 1, it indicates that the granary is in a high-risk state, and measures should be taken immediately.

[0045] Compared with the prior art, the beneficial effects of the present invention are:

[0046] The present invention uses two sensing technologies, fiber Bragg grating and distributed optical fiber, to realize multi-parameter monitoring inside the granary, improves the multi-parameter measurement efficiency of the facilities to be measured, reduces costs, and has a simple device

[0047] The present invention also generates a granary environment warning coefficient that can reflect the risk status of the granary by comprehensively analyzing various granary environment data. This granary environment warning coefficient is generated by comprehensively analyzing various granary environment data and can provide an important basis for the warning of the granary environment. Brief Description of the Drawings

[0048] Figure 1 It is a schematic diagram of the overall system structure of the present invention.

[0049] Figure 2 It is a schematic diagram of the structure of the optical fiber acquisition unit.

[0050] Figure 3 It is a schematic diagram of the structure of the fiber Bragg grating acquisition unit. Detailed Embodiments

[0051] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with specific embodiments.

[0052] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0053] Example:

[0054] See also Figure 1 , the present invention provides a technical solution:

[0055] A comprehensive monitoring system for granary environmental safety based on fiber grating and distributed optical fiber technology, specifically including:

[0056] The data acquisition module is used to divide the granary into N areas, collect the granary environmental data of each area, and convert the collected granary environmental data from optical signals to electrical signals; the granary environmental data includes grain strain data, granary temperature data, vibration amplitude time series data, granary humidity data and carbon dioxide concentration data; the strain data is the height of the grain;

[0057] Temperature is one of the most important factors affecting the safety and quality of grain storage. Temperature changes inside the granary are directly related to the respiratory metabolism of grain, the activity of microorganisms, and the incidence of insect pests. When the temperature is too high, the respiration of grain intensifies, resulting in the loss of moisture and dry matter in the stored grain, which ultimately leads to a decrease in the nutritional value and quality of the grain. In severe cases, it may also cause dangers such as spontaneous combustion. Humidity monitoring is also a key link that cannot be ignored in granary management. When the air humidity is too high, the surface of the grain is easy to absorb moisture, leading to the growth of mold, which in turn causes quality problems such as mold and rot. In an environment with too low humidity, the grain may be over-dried, resulting in weight loss and quality degradation. It is necessary to detect the activities of small animals such as rodents and insects in the warehouse. Vibration data can reflect the activities of small animals such as rodents and insects in the warehouse. Animals pose a threat to the storage of grain. Rodents and insects not only eat grain directly, but also spread pathogens in the grain or cause grain contamination. Height measurement plays an important role in inventory management and scheduling of granaries. By monitoring the height of grain in real time, managers can accurately grasp the inventory of grain in the granary, arrange the shipment plan reasonably, and avoid the waste of storage resources. Monitoring the concentration of carbon dioxide is another important aspect to ensure the safety of grain storage. Changes in the concentration of carbon dioxide in the granary are usually related to the respiration of grain, microbial activity or pest infestation. When the concentration of carbon dioxide in the granary is abnormally high, it may indicate that the grain is in the early stages of fermentation or mildew, or there is a high level of pest activity. Timely detection and treatment of these problems can avoid large-scale deterioration of grain.

[0058] The data acquisition module includes an optical fiber acquisition unit and an optical fiber grating acquisition unit. The optical fiber acquisition unit is used to collect grain strain data, granary temperature data and vibration amplitude time series data; the optical fiber grating acquisition unit is used to collect granary humidity data and carbon dioxide concentration data.

[0059] See also Figure 2 , the optical fiber acquisition unit includes a temperature optical fiber sensor, a vibration optical fiber sensor, a strain optical fiber sensor, a 1550nm narrow linewidth laser, an acousto-optic modulator, erbium-doped fiber amplifiers EDFA 1 and EDFA 2, a circulator, an optical sensing fiber, a wavelength division multiplexer, three photodetectors, a Raman scattering temperature compensation system and a data acquisition card;

[0060] The narrow linewidth laser emits a continuous light wave, which is chopped into pulses by the acousto-optic modulator. The pulses are amplified by EDFA 1 and then injected into the temperature fiber sensor, the vibration fiber sensor and the strain fiber sensor through the circulator. The backscattered light from the temperature fiber sensor, the vibration fiber sensor and the strain fiber sensor is input into the wavelength division multiplexer, where the light is divided into four beams of Brillouin, Rayleigh, Stokes and anti-Stokes. The Brillouin scattering signal reflects the temperature data, which is detected by the photodetector 1. The Stokes and anti-Stokes scattering signals reflect the strain data and are detected by the dual-channel photodetector 2. The Rayleigh scattering signal reflects the vibration data and is detected by the photodetector 3 after being amplified by EDFA 2. The photodetector is used to convert the optical signal into an electrical signal. In addition, a Raman scattering temperature compensation system is designed after the photodetector 1 and the photodetector 2 to eliminate the frequency change caused by the temperature data and the strain data during Brillouin scattering. Please refer to Figure 3 , the fiber grating acquisition unit includes a fiber grating carbon dioxide sensor, a fiber grating humidity sensor, a 1550nm narrow linewidth laser, a circulator, a wavelength division multiplexer and a data acquisition card;

[0061] The narrow linewidth laser emits a continuous light wave, which is incident light into the fiber Bragg grating carbon dioxide sensor and the fiber Bragg grating humidity sensor through a circulator. When the incident light enters the optical fiber, the grating area will reflect a part of the incident light. Finally, all the light that meets the Bragg condition will be superimposed into a reflection peak. The change data of the central wavelength of the reflected light peak is detected by the spectrum analyzer, and the change amount of the parameter to be detected can be calculated. The specific logic for satisfying the Bragg condition is that the wavelength of the incident light is equal to the Bragg wavelength, and the specific formula for obtaining the Bragg wavelength is:

[0062] λ B =2n eff Λ

[0063] Among them, λ B is the Bragg wavelength, n eff is the effective refractive index of the grating, and Λ is the period of the grating.

[0064] After the coating layer is peeled off on the grating part, the moisture-sensitive material and polyether are evenly coated to form an optical fiber humidity sensor and a CO2 gas sensor. After the broadband light emitted by the 1550nm broadband light source enters the circulator, the laser that meets the specific reflection wavelength of the Bragg grating (FBG) in the incident light will be reflected. The circulator can receive this part of the reflected light and send it to the spectrum demodulator, which will demodulate it after receiving the reflected light.

[0065] Data analysis module, used to analyze and process the electrical signals of granary environmental data;

[0066] The specific logic for analyzing and processing the electrical signals of the granary environmental data is as follows: obtaining the historical granary environmental data and the granary environmental data of each area, extracting the abnormal features of the granary environmental data of each area to obtain the granary abnormal feature data, obtaining the risk weights of temperature, height, vibration, humidity and carbon dioxide concentration according to the historical warning conditions, weighting and standardizing the granary abnormal feature data according to the risk weights, and analyzing the weighted and standardized granary abnormal feature data to obtain the granary status index;

[0067] The specific formula used to obtain the risk weights for temperature, grain height, vibration, humidity and carbon dioxide concentration is:

[0068]

[0069] Among them, α i is the risk weight coefficient of the i-th granary environmental data, N is the number of historical granary environmental warnings, and n i is the number of warnings caused by abnormal granary environmental data of the i-th type, i is the index of the type of granary environmental data, and i∈[1,5], the risk weight coefficient α of the i-th type of granary environmental data i Reflects the weight of each type of granary environmental data when the granary issues an early warning.

[0070] The specific formula for weighted normalization of the abnormal characteristic data of granaries in each area is:

[0071]

[0072] Among them, X′ i is the normalized abnormal characteristic data of the i-th granary, X i is the abnormal characteristic data of the i-th granary, X imin is the minimum value of the abnormal characteristic data of the i-th granary, X imax is the maximum value of the abnormal characteristic data of the i-th granary.

[0073] The specific logic for extracting abnormal features from granary environmental data is as follows: the granary temperature data, granary humidity data and carbon dioxide concentration data are processed to obtain temperature abnormality data, humidity abnormality data and carbon dioxide concentration data; the vibration amplitude time series data is Fourier transformed to transform the vibration data into the form of the sum of a series of complex numbers; the amplitude of each frequency in the frequency range of 0-100kHZ is summed to obtain vibration abnormality data; the specific formula for obtaining temperature abnormality data is as follows:

[0074]

[0075] Among them, T Yis the abnormal temperature, T is the granary temperature in the granary area, and T max is the standard maximum temperature, T min It is the standard minimum temperature; the abnormal temperature reflects the degree of temperature abnormality. The larger the value is, the more serious the temperature abnormality is.

[0076] The specific formula for obtaining humidity anomaly data is:

[0077]

[0078] Among them, W Y is the abnormal humidity, W is the granary humidity in the granary area, and W max is the standard maximum humidity, W min It is the standard minimum humidity; abnormal humidity reflects the abnormal degree of temperature. The larger the value is, the more serious the humidity abnormality is.

[0079] The specific formula for obtaining carbon dioxide concentration data is:

[0080]

[0081] Among them, CO Y is the abnormal carbon dioxide concentration, CO is the carbon dioxide concentration in the granary area, and CO max is the standard maximum carbon dioxide concentration, CO min is the standard minimum carbon dioxide concentration; the abnormal carbon dioxide concentration reflects the degree of temperature abnormality. The larger the value, the more serious the abnormal carbon dioxide concentration.

[0082] The abnormal vibration data includes harmful frequency number, harmful amplitude and, the harmful frequency number is the total number of frequencies between 0-100kHz. When mice are active in a granary, they will produce relatively large vibrations, and these vibration frequencies are usually between 1Hz and 10kHz. The vibration frequencies of insect activities are usually higher, and the frequency range is generally between 10Hz and 100kHz.

[0083] The specific formula for obtaining the harmful amplitude and the basis is:

[0084]

[0085] Where P is the harmful amplitude and m is the harmful frequency, F f is the amplitude of the fth harmful frequency, and f is the harmful frequency index. The harmful amplitude and can reflect the impact of rat and insect activities in the granary on grain storage. The larger the value, the greater the impact.

[0086] The specific logic for obtaining the granary status index is as follows: Analyze the abnormal vibration data, abnormal temperature data, abnormal humidity data, and carbon dioxide concentration data to generate a granary environment warning coefficient, and perform statistical analysis on the granary environment warning coefficients of each area to obtain the granary status index; The specific formula for generating the granary environment warning coefficient is:

[0087]

[0088] Where, T Y is the abnormal temperature, W Y is the abnormal humidity, CO Y is the abnormal carbon dioxide concentration, P is the sum of harmful amplitudes, M is the number of harmful frequencies, and Ad is the granary environment warning coefficient for the corresponding area; The granary environment warning coefficient Ad reflects the risk status of the granary. The larger its value, the greater the risk faced by the granary environment and the more unfavorable it is for grain storage. The generation of this coefficient can provide an important basis for the warning of the granary environment.

[0089] The specific formula for obtaining the granary status index is:

[0090]

[0091] Where, Ae is the granary status index, Ad j is the granary environment warning coefficient for the j-th area, and Ad′ is the median of the granary environment warning coefficients. N is the number of granary areas, and j is the granary area index. The granary status index Ae reflects the risk status of the overall granary area. The larger its value, the greater the risk faced by the granary environment. The generation of this coefficient can provide an important basis for the warning of the granary environment.

[0092] The result display module is used to display and give warnings about the analysis and processing results of the electrical signals of the granary environment data.

[0093] The temperature, grain height, vibration, humidity, and carbon dioxide concentration of the granary; The specific logic for the risk warning unit to give warnings is as follows: When the granary environment warning coefficient 0 < Ae ≤ 0.3, the granary is in a low-risk state and the environment is relatively safe; When the granary environment warning coefficient 0.3 < Ae ≤ 0.7, the granary is in a medium-risk state and requires appropriate monitoring and adjustment; When the granary environment warning coefficient 0.7 < Ae ≤ 1, the granary is in a high-risk state and immediate measures need to be taken.

[0094] The above formulas are all dimensionless and take their numerical values for calculation. The formulas are obtained by collecting a large amount of data and performing software simulation to get a formula closest to the actual situation. The preset parameters in the formulas are set by technicians in this field according to the actual situation.

[0095] The above embodiments may be implemented in whole or in part by software, hardware, firmware or any other combination thereof. When implemented by software, the above embodiments may be implemented in whole or in part in the form of a computer program product. Those skilled in the art may appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein may be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software methods depends on the specific application and design constraints of the technical solution.

[0096] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0097] The above description is only a specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application.

Claims

1. A comprehensive monitoring system for granary environmental safety based on fiber Bragg grating and distributed optical fiber technology, characterized in that: Specifically include: The data acquisition module is used to divide the granary into N areas, collect the granary environmental data of each area, and convert the collected granary environmental data from optical signals to electrical signals; the granary environmental data includes grain strain data, granary temperature data, vibration amplitude time series data, granary humidity data and carbon dioxide concentration data; the grain strain data is the grain height; Data analysis module, used to analyze and process the electrical signals of granary environmental data; The result display module is used to display and warn the analysis and processing results of the electrical signals of the granary environmental data; The specific logic for analyzing and processing the electrical signals of the granary environmental data is as follows: obtaining the historical granary environmental data and the granary environmental data of each area, extracting abnormal features from the granary environmental data of each area, obtaining the abnormal feature data of the granary, obtaining the risk weights of temperature, height, vibration, humidity and carbon dioxide concentration according to the historical warning conditions, weighting and standardizing the abnormal feature data of the granary according to the risk weights, and analyzing the weighted and standardized abnormal feature data of the granary to obtain the granary status index; The specific formula used to obtain the risk weights for temperature, grain height, vibration, humidity and carbon dioxide concentration is: Among them, α i is the risk weight coefficient of the i-th granary environmental data, N is the number of historical granary environmental warnings, and n i is the number of warnings caused by abnormal granary environmental data of the i-th type, i is the index of the type of granary environmental data, and i∈[1,5]; The specific formula for weighted normalization of the abnormal characteristic data of granaries in each area is: Among them, X′ i is the normalized abnormal characteristic data of the i-th granary, X i is the abnormal characteristic data of the i-th granary, X imin is the minimum value of the abnormal characteristic data of the i-th granary, X imax is the maximum value of abnormal characteristic data of the i-th granary; The specific logic for extracting abnormal features from granary environmental data is as follows: process the granary temperature data, granary humidity data, and carbon dioxide concentration data of each area to obtain temperature abnormality data, humidity abnormality data, and carbon dioxide concentration data; perform Fourier transform on the vibration amplitude time series data, transform the vibration data into the form of the sum of a series of complex numbers, and sum the amplitude of each frequency in the frequency range of 0-100kHZ to obtain vibration abnormality data. The specific formula for obtaining temperature abnormality data is as follows: Among them, T Y is the abnormal temperature, T is the granary temperature in the granary area, and T max is the standard maximum temperature, T min is the standard minimum temperature; The specific formula for obtaining humidity anomaly data is: Among them, W Y is the abnormal humidity, W is the granary humidity in the granary area, and W max is the standard maximum humidity, W min is the standard minimum humidity; The specific formula for obtaining carbon dioxide concentration data is: Among them, CO Y is the abnormal carbon dioxide concentration, CO is the carbon dioxide concentration in the granary area, and CO max is the standard maximum carbon dioxide concentration, CO min is the standard minimum carbon dioxide concentration; The vibration abnormality data includes harmful frequency number, harmful amplitude and harmful frequency number, wherein the harmful frequency number is the total number of frequencies between 0-100 kHz, and the specific formula for obtaining the harmful amplitude and harmful frequency number is as follows: Among them, P is the harmful amplitude and M is the harmful frequency, F is f is the amplitude of the fth harmful frequency, and f is the harmful frequency index; The specific logic for obtaining the granary status index is as follows: abnormal vibration data, abnormal temperature data, abnormal humidity data and carbon dioxide concentration data are analyzed to generate the granary environment warning coefficient, and the granary environment warning coefficient of each area is statistically analyzed to obtain the granary status index; the specific formula for generating the granary environment warning coefficient is as follows: Among them, T Y is the abnormal temperature, W Y Abnormal humidity, CO Y is the abnormal carbon dioxide concentration, P is the harmful amplitude and, M is the harmful frequency, and Ad is the granary environmental warning coefficient of the corresponding area; The specific formula for obtaining the granary status index is: Among them, Ae is the granary status index, Ad j is the granary environmental warning coefficient of the jth area, Ad′ is the median of the granary environmental warning coefficient, N is the number of granary areas, and j is the granary area index; The result display module is divided into a result display unit and a risk warning unit. The results displayed by the result display unit are: the temperature of the granary, the height of the grain, vibration, humidity, and carbon dioxide concentration. The specific logic for the risk warning unit to issue a warning is as follows: when the granary status index is in the range of 0 < Ae ≤ 0.3, it indicates that the granary is in a low-risk state and the environment is safe; when the granary status index is in the range of 0.3 < Ae ≤ 0.7, it indicates that the granary is in a medium-risk state, and monitoring and adjustment are carried out; when the granary status index is in the range of 0.7 < Ae ≤ 1, it indicates that the granary is in a high-risk state, and measures should be taken immediately.

2. According to claim 1, a comprehensive monitoring system for granary environmental safety based on fiber Bragg grating and distributed optical fiber technology is characterized by: The data acquisition module includes an optical fiber acquisition unit and a fiber Bragg grating acquisition unit. The optical fiber acquisition unit is used to acquire grain strain data, granary temperature data, and vibration amplitude time series data; the fiber Bragg grating acquisition unit is used to acquire granary humidity data and carbon dioxide concentration data.

3. The granary environmental safety comprehensive monitoring system based on fiber Bragg grating and distributed optical fiber technology according to claim 2 is characterized by: The optical fiber acquisition unit includes a temperature optical fiber sensor, a vibration optical fiber sensor, a strain optical fiber sensor, a 1550nm narrow linewidth laser, an acousto-optic modulator, erbium-doped fiber amplifiers EDFA 1 and EDFA 2, a circulator, an optical sensing fiber, a wavelength division multiplexer, three photodetectors, a Raman scattering temperature compensation system, and a data acquisition card; The narrow linewidth laser emits continuous light waves, which are chopped into pulses by the acousto-optic modulator. The pulses are amplified by EDFA 1 and then injected into the temperature optical fiber sensor, vibration optical fiber sensor, and strain optical fiber sensor through the circulator. The backscattered light from the temperature optical fiber sensor, vibration optical fiber sensor, and strain optical fiber sensor is input into the wavelength division multiplexer. Among them, the light is divided into four beams: Brillouin, Rayleigh, Stokes, and anti-Stokes. The Brillouin scattering signal reflects the temperature data and is detected by photodetector 1. The Stokes and anti-Stokes scattering signals reflect the strain data and are detected by the dual-channel photodetector 2. The Rayleigh scattering signal reflects the vibration data and is detected by photodetector 3 after being amplified by EDFA 2. The photodetectors are used to convert the optical signal into an electrical signal. In addition, a Raman scattering temperature compensation system is designed after photodetector 1 and photodetector 2 to eliminate the frequency changes caused by temperature data and strain data during Brillouin scattering.

4. The granary environmental safety comprehensive monitoring system based on fiber Bragg grating and distributed optical fiber technology according to claim 2 is characterized by: The fiber Bragg grating acquisition unit includes a fiber Bragg grating carbon dioxide sensor, a fiber Bragg grating humidity sensor, a 1550nm narrow linewidth laser, a circulator, a wavelength division multiplexer, and a data acquisition card; The narrow linewidth laser emits continuous light waves, which are incident into the fiber Bragg grating carbon dioxide sensor and the fiber Bragg grating humidity sensor through the circulator as incident light. When the incident light enters the optical fiber, the grating area will reflect a part of the incident light. Finally, all the light that satisfies the Bragg condition will be superimposed into a reflection peak. By detecting the change data of the central wavelength of the reflection light peak through a spectral analyzer, the change amount of the parameter to be detected can be calculated. The specific logic for satisfying the Bragg condition is: the wavelength of the incident light is equal to the Bragg wavelength. The specific formula for obtaining the Bragg wavelength is: l B =2n eff L Among them, λ B is the Bragg wavelength, n eff is the effective refractive index of the grating, and Λ is the period of the grating.

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