Modularized air quality monitoring system based on LoRa networking

Abstract

The invention discloses a modular air quality monitoring system based on LoRa networking, and the system is characterized in that a plurality of monitoring areas of a construction site are respectively provided with a multi-parameter sensing unit, and the multi-parameter sensing units monitor the air quality data of each monitoring area, thereby improving the reliability of the monitoring data; a relay networking unit and a tail end data communication unit are arranged between the multi-parameter sensing unit and the monitoring and early warning unit, and the relay networking unit conducts continuous force range extending on air quality data and then transmits the air quality data to the tail end data communication unit, so that the tail end data communication unit transmits the air quality data to the monitoring and early warning unit in a relay mode. The communication range is expanded, relay stable transmission of air quality data is achieved, the data transmission efficiency can be improved, and stable transmission of the data in a complex construction environment is guaranteed; furthermore, the monitoring and early warning unit carries out anomaly analysis, prediction and early warning on the air quality data of each monitoring area, and the reliability of monitoring and early warning can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental monitoring, and particularly relates to a modular air quality monitoring system based on LoRa networking. BACKGROUND

[0002] In industrial scenes such as construction sites, safety hazards such as toxic gas leakage, excessive dust, and sudden air quality decline frequently occur, which seriously threaten the health of construction personnel and construction safety. In order to improve air quality, in the prior art, an air quality monitoring system is usually installed in a construction site. A Chinese patent application with publication number CN 120161175A discloses an air detection management system based on construction engineering, which comprises a single detection module, a collection module and a detection module are arranged in any single detection module, the detection module is connected with the collection module, the detection module is used for detecting the gas collected by a plurality of sampling points in any random inspection room, a multi-parameter environment monitor is arranged in the detection module, the multi-parameter environment monitor is provided with a temperature sensor, a humidity sensor, a formaldehyde sensor and a volatile organic compound sensor; a linkage and cooperative control module is arranged, which is used for linkage control of a plurality of single detection modules in a same building at a same time.

[0003] However, the existing air quality monitoring system can meet the demand of detecting multiple gases, but manual inspection is required, and continuous real-time monitoring cannot be realized. In a large construction site, the air quality monitoring efficiency is low, and there are monitoring blind areas and time intervals, which easily leads to accumulation of dangerous gas without being discovered in time, increasing the construction risk.

[0004] Meanwhile, for a construction site with large area, wide space and complex environment, the data transmission efficiency and reliability of the existing air quality monitoring system are insufficient. The commonly used Bluetooth or Wi-Fi communication method has limited transmission distance, and the signal attenuation is serious when facing a large number of steel bars, metals, walls and other obstacles. The monitoring equipment using ZigBee and other short-distance wireless communication methods has certain networking capability, but the communication distance and signal stability are still insufficient, and it is difficult to realize the global coverage of a large construction site.

[0005] Further, the existing air quality monitoring system has insufficient early warning and prediction level. A simple threshold alarm is usually performed, and an alarm is issued when the monitoring data exceeds the preset threshold, but the data is not analyzed in depth and trend prediction, which cannot early warn potential risks, resulting in low reliability of air quality monitoring and early warning.

[0006] Therefore, how to effectively improve the data transmission and monitoring and early warning reliability of the air quality monitoring system in a large construction site has become a problem to be solved in the field. SUMMARY

[0007] In view of the defects of the prior art, the purpose of the present application is to provide a modular air quality monitoring system and method based on LoRa networking with high data transmission efficiency and reliable monitoring and early warning.

[0008] In order to achieve the above-mentioned purpose, the modular air quality monitoring system based on LoRa networking provided by the present application comprises a multi-parameter sensing unit, a relay networking unit, an end data communication unit and a monitoring and early warning unit,

[0009] The multi-parameter sensing unit is distributed in several monitoring areas of the construction site respectively, and is configured to monitor the air quality data in the corresponding monitoring area in real time,

[0010] The relay networking unit is arranged between the multi-parameter sensing unit and the end data communication unit, and is configured to receive the air quality data acquired by each multi-parameter sensing unit and transmit to the end data communication unit respectively,

[0011] The end data communication unit is arranged between the relay networking unit and the monitoring and early warning unit, and is configured to receive the air quality data transmitted by the relay networking unit and relay transmission to the monitoring and early warning unit, and the monitoring and early warning unit is configured to analyze, predict and warn the air quality data.

[0012] Further, the multi-parameter sensing unit comprises a sensor assembly box and a multi-parameter sensing module, and the sensor assembly box is respectively provided with a modular sensing compartment, a LoRa sensing communication module, a power module and an MCU module for plug-in connection with the multi-parameter sensing module.

[0013] Further, the MCU module is configured to control the working state of the multi-parameter sensing module, and to transmit the processed air quality data to the LoRa sensing communication module, and the LoRa sensing communication module is configured to communicate data with the relay networking unit.

[0014] Further, the relay networking unit comprises a LoRa relay receiving module and a LoRa relay sending module, and the LoRa relay receiving module and the LoRa relay sending module can cooperate with each other to communicate data with the LoRa sensing communication module and the end data communication unit.

[0015] Further, the end data communication unit comprises a LoRa end communication module and a WiFi module, the LoRa end communication module is configured to communicate data with the LoRa relay sending module, and converts the LoRa signal data into WiFi signal to transmit to the WiFi module, and the WiFi module can communicate data with the monitoring and early warning unit.

[0016] Further, the terminal data communication unit further comprises a data security module configured to control the data communication state of the LoRa terminal communication module and the WiFi module respectively.

[0017] Further, the monitoring and early warning unit comprises a data analysis module and an early warning module, the data analysis module is configured to memorize and analyze the abnormality of the air quality data, and based on the historical air quality data, a model prediction is made to form an early warning signal to trigger the early warning module.

[0018] The modular air quality monitoring system based on LoRa networking provided by the application is provided with a plurality of parameter sensing units in each monitoring area of the construction site to monitor the air quality data of each monitoring area, which can effectively improve the reliability of the monitoring data.

[0019] Further, the modular air quality monitoring system based on LoRa networking provided by the application uses the monitoring and early warning unit to analyze, predict and warn the air quality data of each monitoring area, which can improve the reliability of the monitoring and early warning. BRIEF DESCRIPTION OF DRAWINGS

[0020] The application will be further described in conjunction with the drawings and specific embodiments.

[0021] Figure 1 The block diagram of the modular air quality monitoring system based on LoRa networking provided by the application;

[0022] Figure 2 The schematic diagram of the modular air quality monitoring system based on LoRa networking provided by the application;

[0023] Figure 3 And Figure 4 The structural schematic diagram of the multi-parameter sensing unit in the application;

[0024] Figure 5 The distribution schematic diagram of the air quality monitoring system in the application;

[0025] Figure 6 The structural schematic diagram of the relay networking unit in the application;

[0026] Figure 7The structural schematic diagram of the terminal data communication unit in the application.

[0027] Reference signs:

[0028] 1. Multi-parameter sensing unit; 10. Sensor assembly box; 11. Multi-parameter sensing module; 12. Modular sensing warehouse; 13. LoRa sensing communication module; 14. Power module; 15. MCU module;

[0029] 2. Relay networking unit; 20. Relay box; 21. LoRa relay receiving module; 22. LoRa relay sending module; 23. LoRa receiving antenna; 24. LoRa sending antenna;

[0030] 3. Terminal data communication unit; 30. Terminal data communication box; 31. LoRa terminal communication module; 32. WiFi module; 33. Data security module;

[0031] 4. Monitoring and early warning unit; 41. Data analysis module; 42. Early warning module. DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, purposes and effects realized by the application easy to understand, the application will be further described below in combination with specific drawings.

[0033] Reference Figure 1 and Figure 2 , which shows an example of the modular air quality monitoring system based on LoRa networking provided by the application.

[0034] As shown in the figure, the modular air quality monitoring system based on LoRa networking of the present application mainly comprises a multi-parameter sensing unit 1, a relay networking unit 2, a terminal data communication unit 3 and a monitoring and early warning unit 4.

[0035] The multi-parameter sensing unit 1 is distributed in several monitoring areas of the construction site respectively, and is configured to monitor the air quality data in the corresponding monitoring area in real time; the relay networking unit 2 is arranged between the multi-parameter sensing unit 1 and the terminal data communication unit 3, and is configured to receive the air quality data obtained by each multi-parameter sensing unit 1 and transmit to the terminal data communication unit 3 respectively; the terminal data communication unit 3 is arranged between the relay networking unit 2 and the monitoring and early warning unit 4, and is configured to transmit the air quality data to the monitoring and early warning unit 4, so as to realize the power range extension and relay transmission of the air quality data, expand the communication range, and effectively improve the data transmission efficiency and reliability; the monitoring and early warning unit 4 performs abnormal analysis, prediction and early warning on the air quality data, which can effectively improve the monitoring reliability.

[0036] In combination with Figure 3 and Figure 4The multi-parameter sensing unit 1 comprises a sensor assembly box 10, and the sensor assembly box 10 is respectively provided with a modular sensing bin 12, a LoRa sensing communication module 13, a power module 14 and an MCU module 15 for pluggable connection with the multi-parameter sensing module 11, so that the modular sensing bin 12, the LoRa sensing communication module 13, the power module 14 and the MCU module 15 can cooperate with the multi-parameter sensing module 11 to realize air quality monitoring and data transmission in the monitoring area.

[0037] Specifically, the multi-parameter sensing module 11 is combined and integrated by a plurality of sensors, which can be adjusted according to the specific construction site situation and monitoring requirements. For example, for underground construction, the multi-parameter sensing module 11 can be combined and integrated by an H2S sensor, a CH4 sensor and a CO sensor, so that the multi-parameter sensing module 11 can monitor the H2S, CH4 and CO content in the air of the underground construction site in real time.

[0038] In this way, the multi-parameter sensing module 11 can meet the monitoring requirements of different construction sites and monitor the air quality data of the construction site in real time.

[0039] In combination Figure 4 In cooperation, the modular sensing bin 12 is formed with a cavity capable of accommodating the multi-parameter sensing module 11 therein, and is provided with an interface for pluggable connection with the multi-parameter sensing module 11, so that the multi-parameter sensing module 11 can be arranged in the modular sensing bin 12 and quickly connected with the LoRa sensing communication module 13, the power module 14 and the MCU module 15.

[0040] In this way, the multi-parameter sensing unit 1 can adapt to different construction sites and sudden monitoring requirements by replacing different multi-parameter sensing modules 11.

[0041] Further, the MCU module 15 is configured to control the working state of the multi-parameter sensing module 11, such as the collection frequency of the multi-parameter sensing module 11, and process the air quality data before transmitting it to the LoRa sensing communication module 13.

[0042] The MCU module 15 is pre-set with a preliminary warning threshold, and the air quality data and the preliminary warning threshold are compared and analyzed. If the air quality data reaches the preliminary warning threshold, the MCU module 15 directly triggers the warning device arranged at the construction site, so as to directly issue an alarm at the data monitoring end of the multi-parameter sensing unit 1, thereby improving the warning efficiency.

[0043] If the air quality data does not reach the preliminary warning threshold, the MCU module 15 performs cross-sensor data verification on the air quality data, constructs a LoRaWAN data packet and transmits it to the LoRa sensing communication module 13. If the air quality data does not reach the preliminary warning threshold, the MCU module 15 performs cross-sensor data verification on the air quality data, constructs a LoRaWAN data packet and transmits it to the LoRa sensing communication module 13.

[0044] As an example, the MCU module 15 first verifies the integrity of the raw data packet of the air quality data collected by the multi-parameter sensing module 11 by the CRC-16 checking algorithm, for example, the MCU module 15 verifies the integrity with the check bit configuration value of 0x8005, and then uses sliding window uniform filtering, for example, the window width N = 5, to eliminate the transient interference data in the air quality data.

[0045] Further, the MUC module 15 performs cross-sensor data checking, for example, the temperature and humidity data of the air quality data and the volatile organic compound data have a correlation, which can verify the correlation between the humidity data and the volatile organic compound data, and ensure the accuracy of the air quality data.

[0046] Then, the MUC module 15 constructs the LoRaWAN data packet, first adds the fixed first data and device code as the data header, for example, the data header is: Header: 0xA0 + device ID (4 Byte); then continues to splice the air quality data as the main content of the data packet, for example, in the air quality monitoring project in the indoor environment, the data can be spliced in the following order: Payload: [PM2.5 (2B), CO2 (2B), TVOC (2B), CRC (2B)]; and select to splice the time and longitude and latitude data according to the needs, for example, Timestamp: UNIX timestamp (4B), GPS: longitude (4B) + latitude (4B), so as to complete the construction of the LoRaWAN data packet.

[0047] In this way, the MCU module 15 performs cross-sensor data checking on the air quality data, constructs the LoRaWAN data packet and then transmits it to the LoRa sensing communication module 13, which can greatly reduce the error rate of the air quality data collected by the multi-parameter sensing module 11. Compared with the direct transmission method of the prior art, after the air quality data is preprocessed by the MCU module 15, the invalid data packet rate can be reduced from 12.7% to 2.3%, the gateway load is reduced by 38%, thereby effectively improving the stability and reliability of the monitoring system.

[0048] In cooperation therewith, the LoRa sensing communication module 13 is configured to be able to communicate data with the relay networking unit 2, and transmit the air quality data preprocessed by the MUC module 15 to the relay networking unit 2 in the form of LoRa radio, so as to ensure the transmission stability of the air quality data.

[0049] As an example, in this example, the LoRa sensor communication module 13 is constructed based on the E32-400T30S LoRa module, the working frequency band covers 410.125MHz to 493.125MHz, the maximum transmission power can reach 30dBm, and the receiving sensitivity reaches -135dBm, thereby ensuring the transmission stability of the air quality data.

[0050] Further, the LoRa sensor communication module 13 is based on adaptive spread spectrum technology, which can adjust the spread spectrum factor according to the environmental noise intensity of the construction site. For example, in a chemical plant site with dense metal towers, the communication distance of the LoRa sensor communication module 13 is adjusted to 1 kilometer, which is much better than the transmission distance of 200 meters of the traditional WiFi communication module, thereby ensuring the stability of data communication.

[0051] In addition, the multi-parameter sensing unit 1 is also provided with a power module 14, which is configured to provide working power for the multi-parameter sensing module 11, the LoRa sensor communication module 13 and the MCU module 15. Preferably, the power module 14 is composed of a main power supply and a backup power supply to realize the redundancy of the power module 14 and ensure the stable and continuous work of the multi-parameter sensing unit 1.

[0052] Here, the power module 14 is a conventional technical means in the art, which is not described here.

[0053] The multi-parameter sensing unit 1 thus formed is distributed in several monitoring areas of the construction site to monitor the air quality data in each monitoring area in real time, improve the monitoring accuracy, and transmit the air quality data corresponding to each monitoring area to the relay networking unit 2 respectively.

[0054] In combination Figure 5 As an example, in this example, the logistics area, auxiliary area, storage area and process device area of the construction site form monitoring areas respectively, and the multi-parameter sensing unit 1 is distributed in the logistics area, auxiliary area, storage area and process device area to monitor the air quality data in each monitoring area in real time and transmit the air quality data corresponding to each monitoring area to the relay networking unit 2 respectively.

[0055] In combination Figure 6 Further, the relay networking unit 2 is arranged between the multi-parameter sensing unit 1 and the terminal data communication unit 3, which is configured to receive the air quality data obtained by each multi-parameter sensing unit 1 and transmit it to the terminal data communication unit 4 respectively, thereby extending the range of the air quality data and ensuring the stable transmission of the air quality data in the wide space of the large construction site.

[0056] Specifically, the relay networking unit 2 is composed of a relay, including a relay box 20 and a LoRa relay receiving module 21 and a LoRa relay sending module 22 arranged in the relay box 20.

[0057] Further, the LoRa relay receiving module 21 and the LoRa relay sending module 22 are respectively connected and matched with a LoRa receiving antenna 23 and a LoRa sending antenna 24 arranged outside the relay box 21, so as to improve the stability of data communication.

[0058] Preferably, the LoRa receiving antenna 23 and the LoRa sending antenna 24 are respectively arranged at the bottom of the relay box 20, and there is no opening except the bottom, so as to avoid equipment failure caused by rainwater.

[0059] In this way, the relay networking unit 2 can communicate data with the LoRa sensing communication module 13 of the multi-parameter sensing unit 1 and the terminal data communication unit 4 through the cooperation of the LoRa relay receiving module 21 and the LoRa relay sending module 22.

[0060] Among them, the air quality data obtained by the multi-parameter sensing unit 1 is received through the LoRa relay receiving module 21, and the air quality data is transmitted to the terminal data communication unit 4 through the LoRa relay sending module 22, so as to realize signal relay of the air quality data and ensure that the air quality data can be transmitted to a farther distance.

[0061] Further, the arrangement distance and the number of the relay networking unit 2 can be adaptively adjusted according to the construction site situation, so that the data communication distance of the relay networking unit 2 can be adapted to different construction sites.

[0062] In combination Figure 5 , as an example, in this example, in order to meet the stable communication of the construction site, one relay networking unit 2 is respectively arranged in the logistics area, the auxiliary area, the storage area and the process device area of the construction site, so that the relay networking unit 2 in each monitoring area can be connected with all multi-parameter sensing units 1 in the area, thereby arranging four relay networking units 2 to cover the communication range of the construction site.

[0063] In some embodiments, based on the data communication distance of the relay networking unit 2, for a flat construction site, one relay networking unit 2 is deployed per 100,000 square meters, for a high-rise building construction site, one relay networking unit 2 is arranged per 3 floors, and for a low underground construction site, one relay networking unit 2 is configured per 5,000 square meters, and each relay networking unit 2 is respectively connected with each multi-parameter sensing unit 1 in the corresponding area range, so as to ensure that in different construction sites, the relay networking units 2 can cooperate with each other to transmit the air quality data in the corresponding area range to the terminal data communication unit 4.

[0064] In cooperation therewith, the terminal data communication unit 4 is arranged between the relay networking unit 2 and the monitoring and early warning unit 4, preferably, the terminal data communication unit 4 is arranged in the area close to the monitoring and early warning unit 4, and the terminal data communication unit 4 is configured to receive the air quality data transmitted by the relay networking unit 2 and relay transmission to the monitoring and early warning unit 4, thereby expanding the communication range and ensuring stable long-distance communication of the air quality data.

[0065] In combination Figure 5 For example, in this example, the terminal data communication unit 4 and the monitoring and early warning unit 4 are arranged in the office area of the construction site, so that the terminal data communication unit 4 is close to the monitoring and early warning unit 4, thereby improving the stability and efficiency of data communication.

[0066] In combination Figure 7 Specifically, the terminal data communication unit 3 includes a terminal data communication box 30 and a LoRa terminal communication module 31 and a WiFi module 32 arranged in the terminal data communication box 30.

[0067] The LoRa terminal communication module 31 is configured to communicate data with the LoRa relay transmission module 21 of the relay networking unit 2 and receive air quality data.

[0068] In order to realize the rapid transmission of air quality data to the monitoring and early warning unit 4, the LoRa terminal communication module 31 can also convert the air quality data of the LoRa signal into a WiFi signal, so that the WiFi module 32 can transmit the air quality data of the WiFi signal to the monitoring and early warning unit 4, which is compatible with the computer and server data transmission mode of the monitoring and early warning unit 4.

[0069] For example, the conversion of the LoRa signal air quality data into the WiFi signal by the LoRa terminal communication module 31 mainly includes three layers of processing. First, the physical layer conversion is performed, and the IQ data sampling of the LoRa signal air quality data is performed, for example, the LoRa terminal communication module 31 is built-in SX1301 baseband chip, and the physical layer conversion is performed by using the SX1301 baseband chip. Then, the LoRa terminal communication module 31 performs protocol conversion layer, and the frame structure conversion from LoRaWAN MAC layer to 802.11n is realized by dynamic memory mapping, and the WiFi signal is converted. Further, the LoRa terminal communication module 31 performs QOS guarantee, and adds a priority queue in the conversion process, and sets a 3-level QoS strategy, for example, according to the specific application, the data transmission priority of PM2.5>CO2>TVOC is ensured, so as to ensure the accuracy of signal conversion.

[0070] Further, the terminal data communication unit 3 further comprises a data security module 33, which is configured to control the data communication state of the LoRa terminal communication module 31 and the WiFi module 32 respectively, to ensure the transmission safety of the air quality data.

[0071] As an example, the data security module 33 adopts encrypted transmission in the data communication between the LoRa terminal communication module 31 and the LoRa relay transmission module 21, the data communication between the LoRa terminal communication module 31 and the WiFi module 32, and the data communication between the WiFi module 32 and the monitoring and early warning unit 4, to ensure that the air quality data conforms to the LoRaWAN Class C standard frame structure, and to encrypt the data load using the AES-128 algorithm, while updating the key every 24 hours.

[0072] Further, the data security module 33 attaches a 4-byte message integrity code (MIC) to each frame of air quality data, to ensure the reliability of data transmission, and the data security module 33 is also provided with a retransmission mechanism to retransmit data when no lower-end confirmation signal is received, and sets the maximum number of retries to 3, to ensure that the actual test packet loss rate is less than 0.1%.

[0073] Therefore, the terminal data communication unit 3 can relay the air quality data transmitted by the relay networking unit 2 to the monitoring and early warning unit 4, and ensure the stability and safety of data transmission, without expanding the communication range, so that the air quality data can be stably transmitted in a large construction site.

[0074] In cooperation therewith, the monitoring and early warning unit 4 is configured to perform anomaly analysis, prediction and early warning on the air quality data, to improve the monitoring reliability.

[0075] Specifically, the monitoring and early warning unit 4 comprises a data analysis module 41 and an early warning module 42, the data analysis module 41 is configured to perform memory and anomaly analysis on the air quality data, and to perform model prediction based on historical air quality data, to form a multi-level early warning signal to trigger the early warning module 42, so as to issue a multi-level alarm.

[0076] Further, the data analysis module 41 performs anomaly analysis on the air quality data based on a threshold, and predefines a monitoring threshold corresponding to each multi-parameter in the air quality data, and analyzes and compares each multi-parameter with the monitoring threshold, if any parameter reaches the monitoring threshold, the data analysis module 41 generates a first-level early warning signal and transmits it to the early warning module 42, so that the early warning module 42 issues a first-level alarm.

[0077] For example, when the CO concentration in the air quality data exceeds the CO concentration threshold in the monitoring threshold, or / and the CH4 concentration in the air quality data exceeds the CH4 concentration threshold in the monitoring threshold, the data analysis module 41 generates a first-level warning signal and transmits it to the warning module 42, so that the warning module 42 issues an audible and visual alarm and sends a short message to the responsible personnel.

[0078] Further, the data analysis module 41 also uses AI algorithms and historical data analysis functions to perform anomaly analysis on the air quality data, and identifies sensor abnormal data (such as CO sensor drift error > ± 2 ppm) through the Isolation Forest algorithm.

[0079] As an example, when the data analysis module 41 identifies sensor abnormal data through the Isolation Forest algorithm, it first performs data standardization processing, establishes a historical data set for the historical data of the air quality data, and performs Z-score standardization processing, then constructs a tree structure, randomly selects sub-samples to construct an iTree forest, for example, selects ψ = 256 sub-samples to construct an iTree forest (t = 100 trees), then the data analysis module 41 performs path calculation based on the iTree forest,

[0080] Specifically, where c(n) = 2H(n-1)-2(n-1) / n, H is the harmonic number, to obtain abnormal data.

[0081] Further, the data analysis module 41 performs model prediction on the air quality data, analyzes historical air quality data using an LSTM model to predict the trend of air quality data, and thus issues an early warning.

[0082] As an example, the data analysis module 41 constructs a prediction model for analyzing historical air quality data using an LSTM model, the input layer is a 72-hour time series data window (feature dimension 6), the hidden layer is 2-layer LSTM units (units = 128), the training parameter is Adam optimizer (learning_rate = 0.001), and the early stopping strategy (patience = 15) is used to obtain the predicted value. According to the specific application, the early stopping strategy is set, for example, when the predicted value exceeds 120% of the WHO standard value and lasts for 3 prediction periods, the warning module 42 is triggered to issue a warning.

[0083] At the same time, the data analysis module 41 can also process the air quality data based on time series analysis to predict the trend of air quality data in the next 1 hour, such as gas concentration change,

[0084] As an example, the data analysis module 41 first performs data preprocessing, time alignment processing on the historical data set of the air quality data, for example, a matrix X ∈ R^(n×6) containing 6-dimensional features (PM2.5, CO2, TVOC, temperature, humidity, air pressure) is constructed, and the missing values are processed using the triple exponential smoothing method (Holt-Winters).

[0085] Further, the data analysis module 41 performs time series modeling and trend analysis, and uses STL (Seasonal-Trend decomposition using LOESS) to split the sequence into Y t = T t + S t + R t , wherein the period parameter can be set to 24 hours (daily cycle), and an ARIMA(p, d, q) prediction model is established accordingly.

[0086] Then, the data analysis module 41 performs dynamic threshold calculation, for example, a control chart based on EWMA (exponential weighted moving average) is constructed, etc., to predict the trend of the air quality data.

[0087] In this way, the data analysis module 41 respectively predicts the air quality data based on the LSTM model and the time series, thereby generating a secondary warning signal and transmitting it to the warning module 42, so that the warning module 42 issues a secondary alarm.

[0088] At the same time, the data analysis module 41 can also be based on the air quality data to link with the equipment in the construction site, if any parameter in the air quality data reaches the monitoring threshold, and continuously exceeds the threshold within the preset time period, the data analysis module 41 generates a tertiary warning signal and transmits it to the warning module 42, so that the warning module 42 issues a tertiary alarm and controls the working state of the equipment related to the parameter.

[0089] As an example, when the PM2.5 concentration in the air quality data exceeds the PM2.5 concentration threshold in the monitoring threshold and continuously exceeds the threshold, the data analysis module 41 generates a tertiary warning signal and transmits it to the warning module 42, so that the warning module 42 issues a tertiary alarm and starts the sprinkler system to spray water.

[0090] Here, the warning module 42 is a conventional technical means in the art, which will not be described here.

[0091] The monitoring and warning unit 4 thus constituted performs abnormal analysis and prediction on the air quality data by the data analysis module 41, respectively generates multi-level warning signals to trigger the warning module 42, thereby issuing multi-level alarms.

[0092] The above shows and describes the basic principles, main features and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above-mentioned embodiments, and the above-mentioned embodiments and descriptions in the specification are only to illustrate the principles of the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A modular air quality monitoring system based on LoRa networking, used in conjunction with construction sites, characterized in that, The multi-parameter sensing unit, the relay networking unit, the terminal data communication unit and the monitoring and early warning unit, The multi-parameter sensing unit is distributed in a plurality of monitoring areas of the construction site and is configured to monitor air quality data in the corresponding monitoring area in real time. The relay networking unit is arranged between the multi-parameter sensing unit and the terminal data communication unit and is configured to receive air quality data obtained by each multi-parameter sensing unit and transmit the air quality data to the terminal data communication unit. The terminal data communication unit is arranged between the relay networking unit and the monitoring and early warning unit and is configured to receive air quality data transmitted by the relay networking unit and relay the air quality data to the monitoring and early warning unit. 2.The LoRa-based modular air quality monitoring system of claim 1, wherein, The multi-parameter sensing unit includes a sensor assembly box and a multi-parameter sensing module. 3.The LoRa-based modular air quality monitoring system of claim 2, wherein, The MCU module is configured to control the working state of the multi-parameter sensing module and transmit the processed air quality data to the LoRa sensing communication module. 4.The LoRa-based modular air quality monitoring system of claim 3, wherein, The relay networking unit includes a LoRa relay receiving module and a LoRa relay sending module. 5.The LoRa-based modular air quality monitoring system of claim 4, wherein, The terminal data communication unit includes a LoRa terminal communication module and a WiFi module. 6.The LoRa-based modular air quality monitoring system of claim 5, wherein, The data security module is configured to control the data communication state of the LoRa terminal communication module and the WiFi module. 7.The LoRa-based modular air quality monitoring system of claim 1, wherein, The monitoring and early warning unit includes a data analysis module and an early warning module. The data analysis module is configured to memorize and analyze abnormal air quality data and perform model prediction based on historical air quality data to form an early warning signal to trigger the early warning module.

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