A carbon dioxide real-time monitoring system based on the Internet of Things

Abstract

The present application relates to the technical field of gas information monitoring, and particularly relates to a carbon dioxide real-time monitoring system based on the Internet of Things. The present application collects carbon dioxide concentration and environmental temperature and humidity based on a carbon dioxide sensor and a temperature and humidity sensor, and periodically calibrates the sensor; also performs communication transmission data based on a transmission mode switching module, so that the data transmission is more accurate and complete, and the carbon dioxide concentration data is compensated and calculated through the environmental temperature and humidity data, so that the obtained carbon dioxide concentration is more accurate, and the subsequent determination of whether the carbon dioxide concentration needs to be adjusted based on the carbon dioxide compensation value or the carbon dioxide compensation value increase rate is accurate; and based on the average decline rate of the carbon dioxide compensation value within the preset time length after the start of the adjustment and the carbon dioxide compensation value at the end of the preset time length, it is determined whether the monitoring state is qualified, and the related parameters are adjusted based on the monitoring state. The present application improves the monitoring efficiency of carbon dioxide.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas information monitoring, and in particular to a carbon dioxide real-time monitoring system based on the Internet of Things. BACKGROUND

[0002] Carbon dioxide (CO2) is a key gas that affects human health and production planting efficiency. In an indoor environment, high CO2 concentration can cause dizziness and lack of concentration in humans; in an industrial workshop, excessive CO2 concentration can cause safety accidents; in an agricultural greenhouse, CO2 concentration directly affects the photosynthesis efficiency of crops. Therefore, real-time and accurate monitoring of CO2 concentration is of great significance.

[0003] The existing CO2 monitoring system has the following disadvantages: low detection accuracy, greatly affected by temperature and humidity, sensor drifts easily during long-term use, and lacks effective compensation and calibration mechanism; single data transmission mode, mostly using single WiFi or wired transmission, which cannot adapt to the distance and power consumption requirements of different scenes, and has high data transmission delay, and uploading massive data to the cloud directly can easily cause bandwidth congestion; weak fault recognition ability, unable to discover sensor or transmission module failure in time, affecting monitoring reliability.

[0004] Chinese Patent Publication No. CN108983687A discloses a greenhouse carbon dioxide concentration monitoring Internet of Things system, which comprises a signal analysis and acquisition module, a data storage module, a sensor module, and an acquisition and monitoring module; the signal analysis and acquisition module, the data storage module, and the sensor module are connected in sequence; the acquisition and monitoring module is connected with the data storage module and the sensor module.

[0005] It can be seen that the existing technology has the following problems: the existing carbon dioxide monitoring system has low precision and slow response, resulting in low monitoring efficiency of carbon dioxide. SUMMARY

[0006] Therefore, the present application provides a carbon dioxide real-time monitoring system based on the Internet of Things to overcome the problem of low precision and slow response of the existing carbon dioxide monitoring system, resulting in low monitoring efficiency of carbon dioxide.

[0007] To achieve the above purpose, the present application provides a carbon dioxide real-time monitoring system based on the Internet of Things, comprising:

[0008] The acquisition unit comprises a carbon dioxide sensor for collecting carbon dioxide concentration data, a temperature and humidity sensor for collecting environmental temperature and humidity data, and a calibration module for periodically calibrating the carbon dioxide sensor and the temperature and humidity sensor based on a gas concentration curve drawn based on a preset standard carbon dioxide concentration;

[0009] an edge processing unit, comprising a transmission mode switching module configured to transmit the data collected by the acquisition unit, and a calculation module configured to calculate a carbon dioxide compensation value based on the carbon dioxide concentration data and the ambient temperature and humidity data;

[0010] a detection unit configured to determine whether to adjust to reduce the carbon dioxide concentration based on the carbon dioxide compensation value and a preset safety threshold, or an increasing rate of the carbon dioxide compensation value within a preset time;

[0011] an analysis unit configured to determine whether a monitoring state is qualified based on an average decreasing speed of the carbon dioxide compensation value within a preset time period after the adjustment measure is initiated and the carbon dioxide compensation value at the end of the preset time period, adjust the preset time period based on the monitoring state, and adjust parameters in the calculation module based on the monitoring state after the preset time period is adjusted.

[0012] Further, the transmission mode switching module is further configured to automatically determine the transmission mode based on transmission signal strength and transmission time delay.

[0013] Further, the calculation module is configured to correct the carbon dioxide concentration based on a compensation model at least based on a preset reference temperature and a preset reference humidity, wherein the compensation model is wherein C is the carbon dioxide compensation value, C1 is the collected carbon dioxide concentration, is the preset reference temperature, is the preset reference humidity, T is the collected ambient temperature, is the collected ambient humidity, is a temperature compensation coefficient, is a humidity compensation coefficient.

[0014] Further, the analysis unit is further configured to, in the case that the monitoring state is unqualified, adjust the preset time period based on a ratio of the carbon dioxide compensation value to a preset value if an average decreasing speed of the carbon dioxide compensation value within the preset time period is greater than or equal to a preset decreasing speed and the carbon dioxide compensation value is greater than the preset value, wherein the monitoring state is determined to be unqualified when the average decreasing speed of the carbon dioxide compensation value within the preset time period is less than the preset decreasing speed or the carbon dioxide compensation value is greater than the preset value.

[0015] Further, the analysis unit is further configured to increase the preset time period based on the ratio of the carbon dioxide compensation value to the preset value, and the increase amplitude of the preset time period is proportional to the ratio.

[0016] Further, the acquisition unit further comprises a sensor correction module configured to correct a calibration period of the sensor determined based on a gas concentration curve plotted based on a preset standard carbon dioxide concentration; the analysis unit is further configured to repeatedly adjust the preset time length at least once until the adjustment number is less than a preset number and the monitoring state is qualified or the adjustment number is equal to the preset number, or stop adjusting when the monitoring state is unqualified after the preset time length is adjusted; the analysis unit is further configured to calculate an average value of absolute values of a plurality of compensation residuals based on the acquired carbon dioxide compensation values at a plurality of historical time points and the carbon dioxide concentrations collected at the corresponding time points when the monitoring state is unqualified after the adjustment is stopped; the analysis unit is further configured to start the sensor correction module to run and adjust the calibration period based on a difference between the average value and a preset average value when the average value is greater than the preset average value.

[0017] Further, the analysis unit is further configured to reduce the calibration period based on the difference between the average value and the preset average value, and the reduction amplitude of the calibration period is proportional to the difference.

[0018] Further, the analysis unit is further configured to calculate a first correlation coefficient of a compensation residual sequence and a temperature sequence and a second correlation coefficient of the compensation residual sequence and the temperature sequence based on the acquired carbon dioxide compensation values at a plurality of historical time points, the carbon dioxide concentrations collected at the corresponding time points, and the environmental temperature and humidity at the corresponding time points when the monitoring state is unqualified after the calibration period is adjusted; the analysis unit is further configured to correct by using a compensation coefficient adjustment module in the edge computing unit when an absolute value of the first correlation coefficient is greater than a first preset threshold value, or an absolute value of the second correlation coefficient is greater than a second preset threshold value, wherein the first preset threshold value and the second preset threshold value are both greater than zero.

[0019] Further, the compensation coefficient adjustment module is configured to adjust the temperature compensation coefficient based on a ratio of the absolute value of the first correlation coefficient to the first preset threshold value; the compensation coefficient adjustment module is further configured to adjust the humidity compensation coefficient based on a ratio of the absolute value of the second correlation coefficient to the second preset threshold value.

[0020] Further, the compensation coefficient adjustment module is further configured to increase the temperature compensation coefficient based on a ratio of the first correlation coefficient to the first preset threshold when the first correlation coefficient is greater than zero and greater than the first preset threshold, and the increase amplitude of the temperature compensation coefficient is proportional to the ratio; the compensation coefficient adjustment module is further configured to decrease the temperature compensation coefficient based on a ratio of an absolute value of the first correlation coefficient to the first preset threshold when the first correlation coefficient is less than zero and the absolute value of the first correlation coefficient is greater than the first preset threshold, and the decrease amplitude of the temperature compensation coefficient is proportional to the ratio; the compensation coefficient adjustment module is further configured to increase the humidity compensation coefficient based on a ratio of the second correlation coefficient to the second preset threshold when the second correlation coefficient is greater than zero and greater than the second preset threshold, and the increase amplitude of the humidity compensation coefficient is proportional to the ratio; the compensation coefficient adjustment module is further configured to decrease the humidity compensation coefficient based on a ratio of an absolute value of the second correlation coefficient to the second preset threshold when the second correlation coefficient is less than zero and the absolute value of the second correlation coefficient is greater than the second preset threshold, and the decrease amplitude of the humidity compensation coefficient is proportional to the ratio.

[0021] Compared with the prior art, the present application has the beneficial effects that the present application collects carbon dioxide concentration and environmental temperature and humidity based on a carbon dioxide sensor and a temperature and humidity sensor, and periodically calibrates the sensors; also performs communication transmission data based on a transmission mode switching module, so that the data transmission is more accurate and complete, and the carbon dioxide concentration data is compensated and calculated based on the environmental temperature and humidity data, so that the obtained carbon dioxide concentration is more accurate, so that the subsequent determination of whether the carbon dioxide concentration needs to be adjusted based on the carbon dioxide compensation value or the carbon dioxide compensation value increase rate is more accurate; and based on the average decrease speed of the carbon dioxide compensation value within the preset time period after starting the adjustment and the carbon dioxide compensation value at the end of the preset time period, it is determined whether the monitoring state is qualified, and the related parameters are adjusted based on the monitoring state. The present application improves the monitoring efficiency of carbon dioxide.

[0022] Further, the present application automatically determines the transmission mode based on the transmission signal strength and the transmission time delay through the transmission mode switching module, which can transmit information more timely and accurately by automatically switching the transmission mode, thereby further improving the monitoring efficiency of carbon dioxide.

[0023] Further, the present application at least based on a preset reference temperature and a preset reference humidity, uses a compensation model to correct the carbon dioxide concentration, which can make the obtained carbon dioxide concentration more accurate, so that the subsequent adjustment based on the obtained carbon dioxide concentration is more effective, thereby further improving the monitoring efficiency of carbon dioxide.

[0024] Further, the preset time length is adjusted based on the ratio of the carbon dioxide compensation value to the preset value, the monitoring state after the adjustment measure is started can be monitored more effectively by adjusting the preset time length, and thus the monitoring efficiency of the carbon dioxide is further improved.

[0025] Further, the reason for the unqualified monitoring state is determined based on the carbon dioxide compensation values at the plurality of historical moments and the carbon dioxide concentrations collected at the corresponding moments, whether the unqualified monitoring state is caused by the drift of the sensor can be determined more effectively, and thus the subsequent adjustment can be more effectively performed, and thus the monitoring efficiency of the carbon dioxide is further improved.

[0026] Further, the calibration period of the sensor is adjusted based on the difference between the average value and the preset average value, the calibration period of the sensor can be more effectively adjusted, and thus the obtained carbon dioxide concentration is more accurate, and thus the monitoring efficiency of the carbon dioxide is further improved.

[0027] Further, the reason for the unqualified monitoring state is determined based on the size relationship between the absolute value of the first correlation coefficient and the first preset threshold value, or the size relationship between the absolute value of the second correlation coefficient and the second preset threshold value, and thus the subsequent adjustment can be more effectively performed, and thus the monitoring efficiency of the carbon dioxide is further improved.

[0028] Further, the temperature compensation coefficient is adjusted based on the ratio of the first correlation coefficient to the first preset threshold value, and the humidity compensation coefficient is adjusted based on the ratio of the second correlation coefficient to the second preset threshold value, and thus the carbon dioxide compensation value can be more accurately calculated, and thus the monitoring efficiency of the carbon dioxide is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 FIG. 1 is a structural schematic diagram of a carbon dioxide real-time monitoring system based on the Internet of Things according to an embodiment of the present application;

[0030] Figure 2 FIG. 2 is a step flowchart of a carbon dioxide real-time monitoring method based on the Internet of Things according to an embodiment of the present application;

[0031] Figure 3 FIG. 3 is a step flowchart for determining based on the average decreasing speed of the carbon dioxide compensation value in the preset time length and the carbon dioxide compensation value at the end of the preset time length according to an embodiment of the present application;

[0032] Figure 4 FIG. 4 is a step flowchart for determining based on the monitoring state after the preset time length is adjusted according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the objects, technical schemes and advantages of the present application clearer, the following further describes the present application with reference to the embodiments; it should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0034] The preferred embodiments of the present application are described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present application and not to limit the protection scope of the present application.

[0035] It should be noted that in the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense and for example, can be fixed connection, can also be detachable connection, or integral connection; can be mechanical connection, can also be electrical connection; can be direct connection, can also be indirect connection through an intermediate medium, and can be internal communication of two elements. Those skilled in the art can understand the specific meaning of the above terms in the present application according to the specific circumstances.

[0036] Please refer to Figure 1 As shown in the figure, it is a structure schematic diagram of the carbon dioxide real-time monitoring system based on the Internet of Things according to the embodiments of the present application.

[0037] The system comprises an acquisition unit, an edge processing unit, a detection unit and an analysis unit.

[0038] The acquisition unit comprises a carbon dioxide sensor for collecting carbon dioxide concentration data, a temperature and humidity sensor for collecting environmental temperature and humidity data, and a calibration module for periodically calibrating the carbon dioxide sensor and the temperature and humidity sensor based on a gas concentration curve drawn according to a preset standard carbon dioxide concentration;

[0039] The edge processing unit is connected with the acquisition unit and comprises a transmission mode switching module for transmitting the data collected by the acquisition unit, and a calculation module for compensating and calculating the carbon dioxide concentration data based on the environmental temperature and humidity data to obtain a carbon dioxide compensation value;

[0040] The detection unit is connected with the edge processing unit and is used to determine whether to adjust to reduce the carbon dioxide concentration based on the carbon dioxide compensation value and a preset safety threshold, or the increasing rate of the carbon dioxide compensation value within a preset time;

[0041] The analysis unit is connected with the detection unit and is used to determine whether the monitoring state is qualified based on the average decreasing speed of the carbon dioxide compensation value within a preset time period after starting the adjustment measure and the carbon dioxide compensation value at the end of the preset time period, adjust the preset time period based on the monitoring state, and adjust the parameters in the calculation module based on the monitoring state after adjusting the preset time period.

[0042] Specifically, in the embodiment, the carbon dioxide sensor adopts an infrared absorption type sensor, the detection range is 0-5000ppm, the response time is less than or equal to 10 seconds, the built-in optical filter reduces the influence of interfering gases, and the detection specificity is improved. The temperature and humidity sensor selects an SHT30 sensor, the detection temperature accuracy is ±0.3℃, the detection humidity accuracy is ±2% RH, and the collected data is used for temperature and humidity compensation of the CO2 concentration to offset the influence of environmental factors on the detection result.

[0043] Specifically, based on the preset standard CO2 concentration curve (0ppm, 1000ppm, 5000ppm three calibration points), the sensor self-calibration is triggered periodically, the reference gas is introduced through the internal pump during the calibration process, the detection deviation is automatically corrected, and the sensor drift problem is solved.

[0044] Please refer to Figure 2 It is a step flow chart of the carbon dioxide real-time monitoring method based on the Internet of Things in the embodiment of the application.

[0045] The step flow of the carbon dioxide real-time monitoring based on the Internet of Things includes:

[0046] S1, collecting carbon dioxide concentration data and environmental temperature and humidity data through the carbon dioxide sensor and the temperature and humidity sensor in the acquisition unit, and periodically calibrating the carbon dioxide sensor and the temperature and humidity sensor based on the preset standard carbon dioxide concentration curve.

[0047] S2, transmitting the data collected by the acquisition unit through the transmission mode switching module in the edge processing unit connected with the acquisition unit, and calculating the compensation value of the carbon dioxide based on the environmental temperature and humidity data to obtain the carbon dioxide compensation value.

[0048] S3, determining whether to adjust based on the carbon dioxide compensation value and the preset safety threshold, or the increasing rate of the carbon dioxide compensation value within the preset time through the detection unit connected with the edge processing unit, so as to reduce the carbon dioxide concentration.

[0049] S4, determining whether the monitoring state is qualified based on the average decreasing speed of the carbon dioxide compensation value within the preset time length after starting the adjustment measure and the carbon dioxide compensation value at the end of the preset time length through the analysis unit connected with the detection unit, adjusting the preset time length based on the monitoring state, and adjusting the parameters in the calculation module based on the monitoring state after adjusting the preset time length.

[0050] Please refer to Figure 3 It is a step flow chart of the embodiment of the application based on the average decreasing speed of the carbon dioxide compensation value within the preset time length and the determination of the carbon dioxide compensation value at the end of the preset time length.

[0051] Specifically, based on the physical response limit of the electrochemical carbon dioxide sensor and the long-term operation stability of the core module, combined with the harsh fault tolerance demand of the early warning accuracy in high-risk environment, and deeply fitting the massive historical concentration fluctuation, device drift and false alarm event data accumulated in long-term networking observation, the numerical setting of the subsequent corresponding preset or critical parameters is carried out.

[0052] Specifically, in the embodiment, taking the civil indoor environment as an example, the preset value L0=1000ppm, and the preset descending speed P0=50ppm / min, then the comparison process of the average descending speed P of the carbon dioxide compensation value and the preset descending speed P and the ratio of the carbon dioxide compensation value L and the preset value L0 is as follows:

[0053] If the average descending speed P of the carbon dioxide compensation value is less than the preset descending speed P, or the carbon dioxide compensation value L is greater than the preset value L0, it is determined that the monitoring state is unqualified.

[0054] If the average descending speed P of the carbon dioxide compensation value is greater than or equal to the preset descending speed P and the carbon dioxide compensation value L is less than or equal to the preset value L0, it is determined that the monitoring state is qualified.

[0055] Specifically, in the case of unqualified monitoring state, if the average descending speed of the carbon dioxide compensation value is greater than or equal to the preset descending speed and the carbon dioxide compensation value is greater than the preset value within the preset time length, it indicates that the preset adjustment time length of the system is too short, and the concentration has not been reduced to the safety line below to stop ventilation, then the preset time length is adjusted based on the ratio of the carbon dioxide compensation value and the preset value, wherein the preset ratio Q0 of the carbon dioxide compensation value and the preset value is 1.5, and the comparison process of the ratio Q of the carbon dioxide compensation value and the preset value and the preset ratio Q0 is as follows:

[0056] If the ratio Q of the carbon dioxide compensation value and the preset value is less than or equal to the preset ratio Q0, the preset time length is adjusted to 1.3 times of the original preset time length, wherein the adjusted preset time length is rounded up.

[0057] If the ratio Q of the carbon dioxide compensation value and the preset value is greater than the preset ratio Q0, the preset time length is adjusted to 2.1 times of the original preset time length, wherein the adjusted preset time length is rounded up.

[0058] Please refer to Figure 4 It is a step flow chart of the monitoring state after adjusting the preset time length based on the embodiment of the application.

[0059] Specifically, in the case that the monitoring state is unqualified after adjusting the preset time length, the preset time length is repeatedly adjusted at least once until the adjustment times are less than the preset times and the monitoring state is qualified or the adjustment times are equal to the preset times; in the case that the monitoring state is unqualified after stopping adjustment, based on the acquired carbon dioxide compensation values at multiple historical moments and the carbon dioxide concentrations collected at the corresponding moments, an average value of absolute values of multiple compensation residuals is calculated; if the average value is greater than a preset average value, it indicates that the sensor has systematic drift, so that the compensation model has failed to effectively correct, and then a sensor correction module is started to run, and a calibration period is adjusted based on the difference between the average value and the preset average value, wherein the compensation residual is the difference between the carbon dioxide compensation value and the carbon dioxide concentration corresponding to the historical moment.

[0060] Specifically, the preset difference R0 between the average value of the absolute values of the multiple compensation residuals and the preset average value is 5ppm, and the comparison process between the difference R between the average value and the preset average value and the preset difference R0 is specifically as follows:

[0061] If the difference R between the average value and the preset average value is less than or equal to the preset difference R0, the calibration period is adjusted to 0.9 times of the original calibration period, wherein the adjusted calibration period is rounded up;

[0062] If the difference R between the average value and the preset average value is greater than the preset difference R0, the calibration period is adjusted to 0.76 times of the original calibration period, wherein the adjusted calibration period is rounded up.

[0063] Specifically, in the case that the monitoring state is unqualified after adjusting the calibration period, based on the acquired carbon dioxide compensation values at multiple historical moments, the carbon dioxide concentrations collected at the corresponding moments, and the environmental temperature and humidity at the corresponding moments, a first correlation coefficient of a compensation residual sequence and a temperature sequence, and a second correlation coefficient of the compensation residual sequence and a humidity sequence are calculated; if the absolute value of the first correlation coefficient is greater than a first preset threshold, or the absolute value of the second correlation coefficient is greater than a second preset threshold, it indicates that the compensation coefficient in the compensation model is not suitable, and then a compensation coefficient adjustment module in the edge computing unit is used for correction, wherein the first preset threshold and the second preset threshold are both greater than zero.

[0064] Specifically, the compensation coefficient adjustment module is used to adjust the temperature compensation coefficient based on the ratio of the absolute value of the first correlation coefficient to the first preset threshold; the compensation coefficient adjustment module is also used to adjust the humidity compensation coefficient based on the ratio of the absolute value of the second correlation coefficient to the second preset threshold.

[0065] Specifically, the preset ratio T0 between the absolute value of the first correlation coefficient and the first preset threshold is 1.3, and the comparison process between the ratio T between the absolute value of the first correlation coefficient and the first preset threshold and the preset ratio T0 is specifically as follows:

[0066] when the first correlation coefficient is greater than zero,

[0067] if the ratio T of the first correlation coefficient to the first preset threshold value is less than or equal to a preset ratio T0, the temperature compensation coefficient is adjusted to 1.2 times of the original temperature compensation coefficient, wherein the adjusted temperature compensation coefficient is kept to one decimal place;

[0068] if the ratio T of the first correlation coefficient to the first preset threshold value is greater than the preset ratio T0, the temperature compensation coefficient is adjusted to 1.7 times of the original temperature compensation coefficient, wherein the adjusted temperature compensation coefficient is kept to one decimal place.

[0069] when the first correlation coefficient is less than zero,

[0070] if the absolute value of the first correlation coefficient is less than or equal to a preset ratio T0, the temperature compensation coefficient is adjusted to 0.9 times of the original temperature compensation coefficient, wherein the adjusted temperature compensation coefficient is kept to one decimal place;

[0071] if the absolute value of the first correlation coefficient is greater than the preset ratio T0, the temperature compensation coefficient is adjusted to 0.76 times of the original temperature compensation coefficient, wherein the adjusted temperature compensation coefficient is kept to one decimal place.

[0072] Specifically, the preset ratio U0 of the absolute value of the second correlation coefficient to the second preset threshold value is 1.25, and the comparison process based on the ratio U of the absolute value of the second correlation coefficient to the second preset threshold value to the preset ratio U0 is specifically as follows:

[0073] when the second correlation coefficient is greater than zero,

[0074] if the ratio U of the second correlation coefficient to the second preset threshold value is less than or equal to a preset ratio U0, the humidity compensation coefficient is adjusted to 1.16 times of the original humidity compensation coefficient, wherein the adjusted humidity compensation coefficient is kept to one decimal place;

[0075] if the ratio U of the second correlation coefficient to the second preset threshold value is greater than the preset ratio U0, the humidity compensation coefficient is adjusted to 1.62 times of the original humidity compensation coefficient, wherein the adjusted humidity compensation coefficient is kept to one decimal place.

[0076] when the second correlation coefficient is less than zero,

[0077] if the absolute value of the second correlation coefficient is less than or equal to a preset ratio U0, the humidity compensation coefficient is adjusted to 0.83 times of the original humidity compensation coefficient, wherein the adjusted humidity compensation coefficient is kept to one decimal place;

[0078] If the ratio U of the absolute value of the second correlation coefficient to the second preset threshold value is greater than a preset ratio U0, the humidity compensation coefficient is adjusted to 0.69 times the original humidity compensation coefficient, wherein the adjusted temperature compensation coefficient is kept to one decimal place.

[0079] So far, the technical solutions of the present application have been described in combination with the preferred embodiments shown in the drawings, but those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Those skilled in the art can make equivalent changes or replacements to the related technical features without departing from the principles of the present application, and the technical solutions after the changes or replacements will fall within the protection scope of the present application.

[0080] The above description is only the preferred embodiments of the present application and is not intended to limit the present application; for those skilled in the art, the present application can have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A real-time carbon dioxide monitoring system based on the Internet of Things, characterized in that, include: The acquisition unit includes a carbon dioxide sensor for acquiring carbon dioxide concentration data, a temperature and humidity sensor for acquiring ambient temperature and humidity data, and a calibration module for periodically calibrating the carbon dioxide sensor and the temperature and humidity sensor based on a gas concentration curve plotted according to a preset standard carbon dioxide concentration. An edge processing unit includes a transmission mode switching module for transmitting data collected by the acquisition unit, and a calculation module for performing compensation calculations on the carbon dioxide concentration data based on the ambient temperature and humidity data to obtain a carbon dioxide compensation value. The detection unit is used to determine whether to reduce the carbon dioxide concentration based on the carbon dioxide compensation value and a preset safety threshold, or the rate of increase of the carbon dioxide compensation value within a preset time. The analysis unit is used to determine whether the monitoring status is qualified based on the average rate of decrease of the carbon dioxide compensation value within a preset time after the adjustment measures are initiated and the carbon dioxide compensation value at the end of the preset time. It also adjusts the preset time based on the monitoring status and adjusts the parameters in the calculation module based on the monitoring status after the preset time is adjusted. The calculation module is used to correct the carbon dioxide concentration using a compensation model, based at least on a preset reference temperature and a preset reference humidity. The compensation model is as follows: Where C is the carbon dioxide compensation value, and C1 is the collected carbon dioxide concentration. For the preset reference temperature, The preset baseline humidity is T, and the ambient temperature is T. For the collected ambient humidity, This is the temperature compensation coefficient. This is the humidity compensation coefficient; The analysis unit is also used to adjust the preset time based on the ratio of the carbon dioxide compensation value to the preset value if the average rate of decrease of the carbon dioxide compensation value within a preset time period is greater than or equal to a preset rate of decrease and the carbon dioxide compensation value is greater than a preset value, in the event that the monitoring status is unqualified. If the average rate of decrease of the carbon dioxide compensation value within the preset time period is less than the preset rate of decrease or the carbon dioxide compensation value is greater than the preset value, the monitoring status is determined to be unqualified. The acquisition unit also includes a sensor correction module, which is used to correct the sensor calibration cycle determined by a gas concentration curve plotted based on a preset standard carbon dioxide concentration. The analysis unit is also used to repeatedly adjust the preset time at least once if the monitoring status is not qualified after adjusting the preset time, until the adjustment is stopped when the number of adjustments is less than the preset number and the monitoring status is qualified or the number of adjustments is equal to the preset number. The analysis unit is also used to calculate the average of the absolute values ​​of multiple compensation residuals based on the carbon dioxide compensation values ​​obtained at multiple historical times and the carbon dioxide concentration collected at the corresponding times when the monitoring status is unqualified after the adjustment is stopped. The analysis unit is also used to activate the sensor correction module when the average value is greater than the preset average value, and adjust the calibration cycle based on the difference between the average value and the preset average value. The analysis unit is also used to calculate, in the event that the monitoring status is unqualified after the calibration cycle is adjusted, the first correlation coefficient between the compensation residual sequence and the temperature sequence, and the second correlation coefficient between the compensation residual sequence and the humidity sequence, based on the carbon dioxide compensation values ​​obtained at multiple historical times, the carbon dioxide concentration collected at the corresponding times, and the ambient temperature and humidity at the corresponding times. The analysis unit is further configured to correct the situation using the compensation coefficient adjustment module in the edge processing unit when the absolute value of the first correlation coefficient is greater than a first preset threshold, or when the absolute value of the second correlation coefficient is greater than a second preset threshold. Both the first preset threshold and the second preset threshold are greater than zero.

2. The IoT-based real-time carbon dioxide monitoring system according to claim 1, characterized in that, The transmission mode switching module is also used to automatically determine the transmission mode based on the transmission signal strength and transmission time delay.

3. The IoT-based real-time carbon dioxide monitoring system according to claim 1, characterized in that, The analysis unit is also used to increase a preset duration based on the ratio of the carbon dioxide compensation value to the preset value, and the increase in the preset duration is proportional to the ratio.

4. The IoT-based real-time carbon dioxide monitoring system according to claim 1, characterized in that, The analysis unit is also used to reduce the calibration cycle based on the difference between the average value and the preset average value, and the reduction in the calibration cycle is proportional to the difference.

5. The IoT-based real-time carbon dioxide monitoring system according to claim 1, characterized in that, The compensation coefficient adjustment module is used to adjust the temperature compensation coefficient based on the ratio of the absolute value of the first correlation coefficient to the first preset threshold. The compensation coefficient adjustment module is also used to adjust the humidity compensation coefficient based on the ratio of the absolute value of the second correlation coefficient to the second preset threshold.

6. The IoT-based real-time carbon dioxide monitoring system according to claim 5, characterized in that, The compensation coefficient adjustment module is further configured to increase the temperature compensation coefficient based on the ratio of the first correlation coefficient to the first preset threshold when the first correlation coefficient is greater than zero and greater than the first preset threshold, and the increase in the temperature compensation coefficient is proportional to the ratio. The compensation coefficient adjustment module is further used to reduce the temperature compensation coefficient based on the ratio of the absolute value of the first correlation coefficient to the first preset threshold when the first correlation coefficient is less than zero and the absolute value of the first correlation coefficient is greater than the first preset threshold, and the reduction of the temperature compensation coefficient is proportional to the ratio. The compensation coefficient adjustment module is also used to increase the humidity compensation coefficient based on the ratio of the second correlation coefficient to the second preset threshold when the second correlation coefficient is greater than zero and greater than the second preset threshold, and the increase in the humidity compensation coefficient is proportional to the ratio. The compensation coefficient adjustment module is further used to reduce the humidity compensation coefficient based on the ratio of the absolute value of the second correlation coefficient to the second preset threshold when the second correlation coefficient is less than zero and the absolute value of the second correlation coefficient is greater than the second preset threshold, and the reduction of the humidity compensation coefficient is proportional to the ratio.

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