Carbon dioxide sensor zero backtracking method, device, equipment and medium

Abstract

The application relates to the technical field of gas sensor calibration, and provides a carbon dioxide sensor zero point backtracking method, device, equipment and medium. The method comprises the following steps: placing a sensor to be treated in a preset zero gas environment, collecting corresponding calibration sensor parameters after the sensor is powered on and preheated; calculating a zero point correction value of clean air corresponding to carbon dioxide under the same calibration temperature and humidity according to a preset temperature fitting strategy, a humidity fitting strategy and the calibration sensor parameters, and taking the ratio of the zero point correction value and a zero gas output signal value as a signal response ratio; when the sensor needs to be compensated due to zero point drift, placing the sensor in clean air, collecting current sensor parameters of the sensor after the sensor is powered on and preheated; and performing normalization calibration processing on the output signal collected by the sensor, so as to complete zero point backtracking of the sensor. The method can adapt to zero point calibration under different temperature and humidity environments by combining the temperature and humidity fitting strategy and the signal drift ratio calculation.

Description

Technical Field

[0001] This application relates to the field of gas sensor calibration technology, and in particular to a method, apparatus, device and medium for zero-point backtracking of a carbon dioxide sensor. Background Technology

[0002] Non-dispersive infrared carbon dioxide sensors, with their advantages of high detection accuracy and good selectivity, are widely used in industrial monitoring, smart homes, environmental management, and agricultural production. However, during long-term operation, factors such as light source aging and detector performance degradation can cause zero-point drift in the output signal, directly reducing the accuracy of gas detection. Therefore, regular zero-point calibration is necessary.

[0003] Currently, most mainstream zero-point calibration schemes rely on mechanical structures: one type completes calibration by creating a zero-gas environment through evacuation of the detection chamber, which requires a vacuum pumping device. During the calibration process, the chamber pressure fluctuates significantly, requiring an additional pressure compensation mechanism, making the overall scheme complex. The other type achieves calibration by switching the zero-gas chamber using a motor-driven light-blocking plate, which requires a motor, transmission structure, and a spare chamber. This increases sensor power consumption and hardware costs, as well as the probability of mechanical failure. Summary of the Invention

[0004] This application provides a method, apparatus, device, and medium for zero-point backtracking of a carbon dioxide sensor, aiming to solve the problem that existing zero-point calibration algorithms based on temperature and humidity fitting are only applicable to gas detection scenarios where clean air can be directly used as a zero-point reference. Since clean air contains a fixed concentration of carbon dioxide, it cannot be directly equivalent to a zero-gas environment. Existing temperature and humidity calibration methods cannot directly derive the true zero point of the carbon dioxide sensor. Currently, there is no effective solution that can complete zero-point backtracking using clean air without mechanical assistance and solely through algorithms.

[0005] In a first aspect, embodiments of this application provide a zero-point backtracking method for a carbon dioxide sensor, the method comprising: The sensor to be processed is placed in a preset zero-air environment. After the sensor is powered on and preheated, the corresponding calibration sensor parameters are collected. The calibration sensor parameters include at least the calibration temperature value, the calibration humidity value, and the zero-air output signal value. Based on the preset temperature fitting strategy, humidity fitting strategy, and the calibration sensor parameters, the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity is calculated, and the ratio of the zero-point correction value to the zero-air output signal value is used as the signal response ratio. The temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature changes on the infrared detection signal. The humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity. When the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, powered on and preheated, and then the current sensor parameters are collected; the current sensor parameters include at least the current temperature value, the current humidity value, and the real-time output signal value; Based on the temperature fitting strategy, humidity fitting strategy, current sensor parameters, and signal response ratio, the output signal acquired by the sensor is normalized and calibrated to complete the zero-point backtracking of the sensor.

[0006] In some embodiments, the step of normalizing and calibrating the output signal acquired by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters, and the signal response ratio to complete the zero-point backtracking of the sensor includes: calculating the reference signal value of the carbon dioxide concentration corresponding to the clean air at the current temperature and humidity; calculating the ratio of the real-time output signal value to the reference signal value to obtain the signal drift ratio; calculating the true zero-point signal value corresponding to the zero-air environment at the current temperature and humidity according to the real-time output signal value and the signal response ratio; and performing normalization and calibration processing on the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio.

[0007] In some embodiments, calculating the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity based on the real-time output signal value and the signal response ratio includes: dividing the real-time output signal value by the signal response ratio to obtain the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity conditions.

[0008] In some embodiments, the normalization calibration process for the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio includes: multiplying the output signal value acquired by the sensor by a preset normalization coefficient, then dividing it by the product of the true zero-point signal value and the signal drift ratio, and outputting the calibrated normalized signal value.

[0009] In some embodiments, placing the sensor to be processed in a preset zero-gas environment and collecting the corresponding calibration sensor parameters after the sensor is powered on and preheated includes: placing the sensor to be processed in a nitrogen environment, and after the sensor has completed power-on and preheating, collecting the calibration temperature value, calibration humidity value and zero-gas output signal value output by the sensor respectively.

[0010] In some embodiments, the step of calculating the zero-point correction value of the carbon dioxide concentration in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters includes: calculating the temperature reference signal value corresponding to the calibration temperature value according to the temperature fitting strategy, calculating the humidity reference signal value corresponding to the calibration humidity value according to the humidity fitting strategy, and combining the temperature reference signal value and the humidity reference signal value to obtain the zero-point correction value of the carbon dioxide concentration in clean air.

[0011] In some embodiments, when the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, and after power-on preheating, the current sensor parameters are collected. This includes: when the sensor experiences zero-point drift and requires compensation, the sensor is placed in a clean air environment, and after the sensor has completed power-on preheating, the current temperature value, current humidity value, and real-time output signal value of the sensor are collected respectively.

[0012] Secondly, this application provides a zero-point tracing device for a carbon dioxide sensor, the device comprising: The parameter acquisition unit is used to place the sensor to be processed in a preset zero-air environment and acquire the corresponding calibration sensor parameters after the sensor is powered on and preheated; the calibration sensor parameters include at least the calibration temperature value, the calibration humidity value, and the zero-air output signal value; The ratio calculation unit is used to calculate the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters, and use the ratio of the zero-point correction value to the zero-air output signal value as the signal response ratio; the temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature change on infrared detection signal; the humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity. The drift compensation unit is used to place the sensor in clean air, power it on and preheat it when the sensor experiences zero-point drift and needs compensation, and then collect the current sensor parameters; the current sensor parameters include at least the current temperature value, the current humidity value and the real-time output signal value. The backtracking completion unit is used to perform normalization calibration processing on the output signal collected by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters and the signal response ratio, and complete the zero-point backtracking of the sensor.

[0013] Thirdly, this application provides a computer device, including a memory and a processor; The memory is used to store computer programs; The processor is configured to execute the computer program and, in executing the computer program, implement the method provided in any embodiment of this application.

[0014] Fourthly, this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to implement the method provided in any embodiment of this application.

[0015] This application achieves zero-point calibration through an algorithm, eliminating the need for additional mechanical components such as a vacuum pump and a gas chamber switching mechanism, as well as pressure compensation. This effectively reduces the hardware cost and power consumption of the sensor, decreases the probability of mechanical failure, and simplifies the overall calibration process.

[0016] Meanwhile, on-site calibration only requires placing the sensor in clean air to trace back to the true zero point under zero gas conditions, without the need to introduce nitrogen-type zero gas on-site. The operation is simple and easy to perform, and it is suitable for the zero-point drift compensation needs after long-term use of the sensor.

[0017] By combining temperature and humidity fitting strategies with signal drift ratio calculations, zero-point calibration can be adapted to different temperature and humidity environments, ensuring the accuracy of zero-point backtracking and effectively improving the detection accuracy and stability of carbon dioxide sensors during long-term operation.

[0018] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic flowchart illustrating the steps of a zero-point backtracking method for a carbon dioxide sensor according to an embodiment of this application; Figure 2This is a schematic diagram illustrating the principle of a zero-point backtracking method for a carbon dioxide sensor according to an embodiment of this application; Figure 3 This is a schematic block diagram of a carbon dioxide sensor zero-point tracing device according to an embodiment of this application; Figure 4 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application.

[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] The flowchart shown in the attached diagram is for illustrative purposes only and does not necessarily include all content and operations / steps, nor does it necessarily have to be performed in the order described. For example, some operations / steps can be broken down, combined, or partially merged, so the actual execution order may change depending on the actual situation.

[0024] It should be understood that, in order to clearly describe the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0025] It should be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] Non-dispersive infrared carbon dioxide sensors, with their advantages of high detection accuracy and good selectivity, are widely used in industrial monitoring, smart homes, environmental management, and agricultural production. However, during long-term operation, factors such as light source aging and detector performance degradation can cause zero-point drift in the output signal, directly reducing the accuracy of gas detection. Therefore, regular zero-point calibration is necessary.

[0028] Currently, most mainstream zero-point calibration schemes rely on mechanical structures: one type completes calibration by creating a zero-gas environment through evacuation of the detection chamber, which requires a vacuum pumping device. During the calibration process, the chamber pressure fluctuates significantly, requiring an additional pressure compensation mechanism, making the overall scheme complex. The other type achieves calibration by switching the zero-gas chamber using a motor-driven light-blocking plate, which requires a motor, transmission structure, and a spare chamber. This increases sensor power consumption and hardware costs, as well as the probability of mechanical failure.

[0029] Existing zero-point calibration algorithms based on temperature and humidity fitting are only applicable to gas detection scenarios where clean air can be directly used as a zero-point reference. Since clean air contains a fixed concentration of carbon dioxide, it cannot be directly equated to a zero-gas environment. Existing temperature and humidity calibration methods cannot directly derive the true zero point of the carbon dioxide sensor. Currently, there is no effective solution that can complete zero-point backtracking using clean air without mechanical assistance and solely through algorithms.

[0030] Please refer to Figure 1 and Figure 2 This application provides a zero-point backtracking method for a carbon dioxide sensor, applied to a computer device. The computer device can be deployed on a single server or a server cluster. It can also be deployed on a handheld terminal, laptop, wearable device, or robot, etc.

[0031] This embodiment provides a zero-point backtracking method for a carbon dioxide sensor, which can run on the microcontroller built into the carbon dioxide sensor or on an external computer processing device. The method is divided into two execution stages: factory calibration and field backtracking. The factory calibration stage corresponds to... Figure 2 The factory calibration section is used to complete the calibration of reference parameters and store the signal response ratio; the corresponding field backtracking stage... Figure 2 The field backtracking section is used to perform zero-point calibration and signal correction solely in a clean air environment after the sensor has experienced zero-point drift due to long-term use.

[0032] The provided zero-point backtracking method for carbon dioxide sensors includes steps S101 to S104. Details are as follows: Step S101. Place the sensor to be processed in a preset zero-air environment, and collect the corresponding calibration sensor parameters after the sensor is powered on and preheated; the calibration sensor parameters include at least the calibration temperature value, calibration humidity value and zero-air output signal value.

[0033] Specifically, the carbon dioxide sensor to be calibrated is placed in a preset zero-gas environment, which refers to an inert gas environment free of carbon dioxide, to provide an absolute zero reference for the sensor. After the sensor is powered on, it enters a preheating state, continuously monitoring the output values ​​of the internal infrared light source, photoelectric detection unit, and temperature and humidity detection unit. Once all output values ​​show no significant fluctuations for a preset period of time, the power-on preheating is considered complete.

[0034] After power-on and preheating, the calibration sensor parameters under the current conditions are collected. These parameters include the calibration temperature value, calibration humidity value, and zero-air output signal value. The calibration temperature value is collected by the sensor's built-in temperature detection unit, reflecting the real-time temperature under calibration conditions; the calibration humidity value is collected by the sensor's built-in humidity detection unit, reflecting the real-time humidity under calibration conditions; and the zero-air output signal value is collected by the sensor's infrared photoelectric detection unit, reflecting the sensor's raw electrical signal output under zero-air conditions. This step obtains the reference signal data corresponding to specific temperature and humidity under zero-air conditions, providing the basic input for subsequent signal response ratio calculations.

[0035] Step S102. Based on the preset temperature fitting strategy, humidity fitting strategy, and the calibration sensor parameters, calculate the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity, and use the ratio of the zero-point correction value to the zero-air output signal value as the signal response ratio; the temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature changes on the infrared detection signal; the humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity.

[0036] Specifically, the temperature fitting strategy is pre-established and stored through the following calibration steps: In a standard zero-gas (0 ppm carbon dioxide) environment, five gradient temperature calibration nodes are set at -10℃, 0℃, 25℃, 50℃, and 70℃; after the ambient temperature of each temperature node stabilizes for a preset time, the zero-gas output signal value of the sensor at the corresponding temperature is collected; using the temperature value of each node as the independent variable and the signal offset multiple of the zero-gas output signal of each node relative to the 25℃ reference temperature as the dependent variable, a second-order polynomial temperature correction model is obtained by fitting using the least squares method. The operation logic of this temperature correction model is as follows: after inputting the current temperature value, the corresponding temperature correction multiple is output, where the temperature correction multiple is equal to the sum of the zero-order temperature fitting coefficient, the product of the first-order temperature fitting coefficient and the current temperature value, and the product of the second-order temperature fitting coefficient and the square of the current temperature value; the three sets of temperature fitting coefficients obtained are stored in the sensor's non-volatile storage unit.

[0037] The humidity fitting strategy is pre-established and stored through the following calibration steps: In a standard zero-humidity environment (0 ppm carbon dioxide, 25°C reference temperature), five relative humidity calibration nodes with gradients of 10%RH, 30%RH, 50%RH, 70%RH, and 90%RH are set. After the ambient humidity at each humidity node stabilizes for a preset time, the zero-humidity output signal value of the sensor at the corresponding humidity is collected. Using the relative humidity value of each node as the independent variable and the signal offset ratio of the zero-humidity output signal of each node relative to the 50%RH reference humidity as the dependent variable, a second-order polynomial humidity correction model is obtained by fitting using the least squares method. The operation logic of this humidity correction model is as follows: after inputting the current relative humidity value, the corresponding humidity correction ratio is output, where the humidity correction ratio is equal to the sum of the zero-order humidity fitting coefficient, the product of the first-order humidity fitting coefficient and the current relative humidity value, and the product of the second-order humidity fitting coefficient and the square of the current relative humidity value. The three sets of humidity fitting coefficients obtained are stored in the sensor's non-volatile storage unit.

[0038] The temperature and humidity fitting strategies described above are invoked, and the calibration temperature and humidity values ​​collected in step S101 are input. The temperature correction factor corresponding to the calibration temperature and the humidity correction factor corresponding to the calibration humidity are calculated respectively. Combined with the pre-stored reference output signal value corresponding to the clean air standard concentration of 420ppm carbon dioxide under the reference temperature and humidity conditions of 25℃ and 50%RH, the reference output signal value is multiplied by the temperature correction factor and the humidity correction factor in turn to obtain the zero-point correction value corresponding to the calibration temperature and humidity.

[0039] After obtaining the zero-point correction value, the ratio of the zero-point correction value to the zero-air output signal value acquired in step S101 is calculated, and this ratio is stored as the signal response ratio in the sensor's non-volatile storage unit. The signal response ratio characterizes the fixed proportional relationship between the corrected output signal of clean air with a standard concentration of carbon dioxide and the original output signal under zero-air conditions, under the same temperature and humidity conditions. This step establishes a conversion bridge between the clean air signal and the zero-air zero-point signal, so that subsequent on-site calibration does not require the introduction of zero air; the zero-air zero-point value can be deduced solely from the signal under clean air conditions.

[0040] Step S103. When the sensor experiences zero-point drift and requires compensation, place the sensor in clean air, power it on and preheat it, and then collect the current sensor parameters; the current sensor parameters include at least the current temperature value, the current humidity value, and the real-time output signal value.

[0041] Specifically, when the sensor's cumulative operating time reaches the preset calibration cycle, or when the sensor's self-test determines that the output signal deviation exceeds the allowable range, indicating zero-point drift and requiring compensation, the sensor should be placed in a clean air environment. A clean air environment refers to an air environment where the carbon dioxide concentration is at the normal atmospheric level, there is no interference from additional carbon dioxide sources, and the ventilation is stable, without the need for dedicated gas cylinders and gas path structures.

[0042] After the sensor is powered on, it enters a preheating state, continuously monitoring the output values ​​of each unit within the sensor. Preheating is considered complete when all output values ​​show no significant fluctuations for a preset duration. After preheating, the sensor parameters are collected, including the current temperature, current humidity, and real-time output signal. The current temperature is collected by the sensor's built-in temperature detection unit, reflecting the real-time temperature under the calibration environment; the current humidity is collected by the sensor's built-in humidity detection unit, reflecting the real-time humidity under the calibration environment; and the real-time output signal is collected by the sensor's infrared photoelectric detection unit, reflecting the sensor's raw electrical signal output in the current clean air environment. This step acquires real-time signal data under the calibration environment, providing input parameters for subsequent zero-point backtracking calculations.

[0043] Step S104. Based on the temperature fitting strategy, humidity fitting strategy, current sensor parameters, and signal response ratio, normalize and calibrate the output signal acquired by the sensor to complete the zero-point backtracking of the sensor.

[0044] Specifically, the pre-stored temperature and humidity fitting strategies are invoked, and the current temperature and humidity values ​​collected in step S103 are input. The temperature and humidity correction factors corresponding to the current environment are calculated respectively. The real-time output signal value collected in step S103 is multiplied by the temperature and humidity correction factors in sequence, and then divided by the signal response ratio stored in step S102 to obtain the zero-point signal value of the sensor under the current temperature and humidity conditions. This value is the true zero-point output of the sensor in the current zero-air environment. This zero-point signal value is updated as the zero-point reference parameter of the sensor, and normalization calibration is performed on all subsequent output signals collected by the sensor to eliminate the influence of zero-point drift on the detection accuracy, thus completing the sensor zero-point backtracking.

[0045] This step requires no additional mechanical devices or pressure compensation. It only requires algorithmic calculation to convert the signal under clean air into the true zero point under zero air conditions. At the same time, it compensates for signal drift caused by long-term aging of the sensor, achieving convenient and low-cost zero-point calibration.

[0046] In some embodiments, the step of normalizing and calibrating the output signal acquired by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters, and the signal response ratio to complete the zero-point backtracking of the sensor includes: calculating the reference signal value of the carbon dioxide concentration corresponding to the clean air at the current temperature and humidity; calculating the ratio of the real-time output signal value to the reference signal value to obtain the signal drift ratio; calculating the true zero-point signal value corresponding to the zero-air environment at the current temperature and humidity according to the real-time output signal value and the signal response ratio; and performing normalization and calibration processing on the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio.

[0047] The baseline signal value of carbon dioxide concentration in clean air under the current temperature and humidity is calculated. The current temperature value acquired in step S103 is substituted into the temperature fitting strategy to obtain the signal correction value corresponding to temperature; the current humidity value is substituted into the humidity fitting strategy to obtain the signal correction value corresponding to humidity; the two correction values ​​are combined to calculate the baseline signal value of carbon dioxide concentration in clean air under the current temperature and humidity conditions. The baseline signal value is the theoretical signal value that should be output in clean air at the current temperature and humidity when the sensor does not drift.

[0048] The signal drift ratio is obtained by calculating the ratio of the real-time output signal value to the reference signal value. The signal drift ratio reflects the overall signal shift caused by long-term aging and performance degradation of the sensor, and is used to characterize the magnitude of change in the overall sensitivity of the sensor.

[0049] By combining the real-time output signal value acquired in step S103 with the signal response ratio stored in step S102, the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity is calculated. The true zero-point signal value is the actual zero-point signal that the sensor should output in the zero-air environment under the current temperature and humidity conditions, and it serves as the benchmark reference for sensor concentration calculation.

[0050] By combining the true zero-point signal value with the signal drift ratio, normalization calibration is performed on the output signal subsequently acquired by the sensor. The true zero point is used as the calibration reference, and the overall signal amplitude is corrected by combining the signal drift ratio, so that the calibrated signal is consistent with the factory calibration reference.

[0051] This embodiment calculates the reference signal, drift ratio, and true zero point in steps, which can simultaneously eliminate the dual impact of temperature and humidity changes and long-term sensor aging on the zero point, thereby improving the accuracy and stability of zero point backtracking.

[0052] In some embodiments, calculating the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity based on the real-time output signal value and the signal response ratio includes: dividing the real-time output signal value by the signal response ratio to obtain the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity conditions.

[0053] By dividing the real-time output signal value acquired in step S103 by the signal response ratio pre-stored in step S102, the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity conditions is calculated.

[0054] The calculation principle is as follows: the signal response ratio is a fixed ratio between the clean air signal and the zero air signal under the same temperature and humidity during the factory calibration stage. When the sensor experiences overall drift, the clean air signal and the zero air signal will drift synchronously in the same proportion. Therefore, by dividing the real-time clean air signal measured on-site by the fixed ratio, the true zero point corresponding to the current temperature and humidity can be deduced without the need for on-site measurement with zero air. This embodiment obtains the true zero point through proportional conversion, with low computational load, making it suitable for direct operation in the sensor microcontroller without additional computing power.

[0055] In some embodiments, the normalization calibration process for the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio includes: multiplying the output signal value acquired by the sensor by a preset normalization coefficient, then dividing it by the product of the true zero-point signal value and the signal drift ratio, and outputting the calibrated normalized signal value.

[0056] By multiplying each output signal value subsequently acquired by the sensor by a preset normalization coefficient, and then dividing by the product of the true zero-point signal value and the signal drift ratio, the calibrated normalized signal value is finally output.

[0057] The preset normalization coefficient is a fixed value pre-set at the factory to unify the original signal to a standard dimension range, ensuring consistent output reference across different batches of sensors. The zero-point reference is corrected using the actual zero-point signal value, and the overall signal amplitude is corrected using the signal drift ratio. This ensures that the calibrated normalized signal value is unaffected by changes in temperature and humidity, or sensor aging and drift, always corresponding to a unified concentration conversion reference. The normalized signal value output in this embodiment can be directly used for subsequent carbon dioxide concentration conversion without additional correction steps.

[0058] In some embodiments, placing the sensor to be processed in a preset zero-gas environment and collecting the corresponding calibration sensor parameters after the sensor is powered on and preheated includes: placing the sensor to be processed in a nitrogen environment, and after the sensor has completed power-on and preheating, collecting the calibration temperature value, calibration humidity value and zero-gas output signal value output by the sensor respectively.

[0059] The carbon dioxide sensor to be processed is placed in a nitrogen environment, which is a zero-gas environment created by filling a sealed cavity with high-purity nitrogen. Nitrogen does not contain carbon dioxide, has stable chemical properties, and will not damage the internal components of the sensor. After the sensor is powered on, a preheating timer is started. The sensor is considered to have completed power-on preheating once the intensity of the internal infrared light source stabilizes, the output of the photodetector shows no significant fluctuations, and the values ​​of the temperature and humidity detection elements stabilize.

[0060] After power-on and preheating, the calibrated temperature, calibrated humidity, and zero-gas output signal values ​​from the sensor are collected. During the data acquisition process, a sealed nitrogen environment is maintained to prevent external air infiltration from affecting calibration accuracy. This embodiment uses nitrogen as the zero-gas medium, which is easy to obtain and provides good calibration stability, ensuring the accuracy and reliability of the signal response ratio obtained from factory calibration.

[0061] In some embodiments, the step of calculating the zero-point correction value of the carbon dioxide concentration in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters includes: calculating the temperature reference signal value corresponding to the calibration temperature value according to the temperature fitting strategy, calculating the humidity reference signal value corresponding to the calibration humidity value according to the humidity fitting strategy, and combining the temperature reference signal value and the humidity reference signal value to obtain the zero-point correction value of the carbon dioxide concentration in clean air.

[0062] The temperature reference signal value corresponding to the calibration temperature is calculated based on a temperature fitting strategy. The temperature fitting strategy is based on multiple sets of calibration experimental data at different temperatures, reflecting the influence of temperature changes on the infrared absorption signal of the sensor. By substituting the calibration temperature value into the temperature fitting strategy, the signal correction result corresponding to this temperature, i.e., the temperature reference signal value, can be obtained.

[0063] The humidity reference signal value corresponding to the calibrated humidity value is calculated based on a humidity fitting strategy. The humidity fitting strategy is based on multiple sets of calibration experimental data under different humidity levels, reflecting the interference law of water vapor on infrared light absorption. By substituting the calibrated humidity value into the humidity fitting strategy, the signal correction result corresponding to this humidity level, i.e., the humidity reference signal value, can be obtained.

[0064] By combining the temperature reference signal value and the humidity reference signal value for comprehensive calculation, the zero-point correction value of the carbon dioxide concentration in clean air under the calibrated temperature and humidity conditions is obtained.

[0065] This embodiment uses a method of fitting temperature and humidity separately and then performing comprehensive calculations to accurately obtain the theoretical signal value of clean air carbon dioxide concentration under any temperature and humidity. It has high fitting accuracy and is suitable for application scenarios with wide temperature and humidity ranges.

[0066] In some embodiments, when the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, and after power-on preheating, the current sensor parameters are collected. This includes: when the sensor experiences zero-point drift and requires compensation, the sensor is placed in a clean air environment, and after the sensor has completed power-on preheating, the current temperature value, current humidity value, and real-time output signal value of the sensor are collected respectively.

[0067] When the sensor's cumulative operating time reaches the preset calibration cycle, or when the sensor's self-test output signal deviation exceeds the allowable range, it is determined that the sensor has zero-point drift and requires compensation. At this time, the sensor should be moved to a clean air environment. This clean air environment must be well-ventilated, free from human exhaled gases, and free from carbon dioxide release sources, ensuring that the carbon dioxide concentration in the environment is at a normal atmospheric level.

[0068] After the sensor is powered on, it enters a preheating state. Once the output values ​​of the internal infrared light source, photodetector, and temperature and humidity detection elements stabilize without fluctuation, the sensor is considered to have completed power-on preheating. After power-on preheating is complete, the current temperature value, current humidity value, and real-time output signal value of the sensor are collected. During the data collection process, the sensor position is kept fixed to avoid airflow directly blowing into the sensor chamber, which could cause signal fluctuations.

[0069] This embodiment clarifies the triggering conditions and environmental requirements for on-site calibration, which can ensure the stability and reliability of the parameters collected on-site and improve the final accuracy of zero-point backtracking.

[0070] In some embodiments, this embodiment is an end-to-end implementation that fully covers the entire process of this method, including general gas zero-point compensation logic and a carbon dioxide sensor-specific adaptation scheme, and fully realizes the entire technical process from basic temperature and humidity zero-point calibration to carbon dioxide zero-point backtracking.

[0071] The implementation process of this embodiment is divided into four stages: basic calibration system construction, carbon dioxide scenario adaptation, factory parameter calibration, and on-site zero-point backtracking. The specific implementation method is as follows: The first stage involves constructing a basic temperature and humidity zero-point calibration system. Multiple calibration experiments are conducted beforehand to develop temperature and humidity fitting strategies. The temperature fitting strategy characterizes the variation of the sensor's output signal in a reference gas environment under different ambient temperatures; the humidity fitting strategy characterizes the variation of the sensor's output signal in a reference gas environment under different ambient humidity levels. For detection scenarios where clean air contains no or only trace amounts of the target gas, the sensor can be directly used as a zero-point reference simply by placing it in clean air. When zero-point drift occurs during long-term sensor operation, the sensor is placed in clean air, powered on, preheated, and stabilized before acquiring the current temperature, current humidity, and real-time output signal values. The reference zero-point signal value under the current temperature and humidity is calculated using the temperature and humidity fitting strategies, respectively. The ratio of the real-time output signal value to the reference zero-point signal value is calculated to obtain the signal drift ratio. Subsequently, when normalizing the sensor output signal, the original output signal is multiplied by a preset normalization coefficient and then divided by the product of the reference zero-point signal value and the signal drift ratio to obtain the calibrated normalized signal value, thus completing the zero-point drift compensation for general gas scenarios.

[0072] The second phase involves adapting the system for carbon dioxide detection. Since clean air contains a fixed concentration of carbon dioxide, it cannot be directly used as a zero-point reference. Therefore, the basic calibration system is adjusted: the original zero-point reference corresponding to the fitting strategy is changed to a signal reference corresponding to the carbon dioxide concentration in clean air; the adjusted temperature fitting strategy is used to characterize the change in the sensor's output signal for the carbon dioxide concentration in clean air under different temperatures; the adjusted humidity fitting strategy is used to characterize the change in the sensor's output signal for the carbon dioxide concentration in clean air under different humidity levels. Through this adjustment, the original temperature and humidity calibration logic can be directly reused, requiring only a conversion relationship to trace back to the true zero point.

[0073] The third stage involves performing the factory-calibrated baseline parameters. The sensor is placed in a zero-air environment, powered on, and preheated until the output stabilizes. Calibration temperature, calibration humidity, and zero-air output signal values ​​are then collected. The calibration temperature and humidity values ​​are substituted into the adjusted temperature and humidity fitting strategy to calculate the zero-point correction value corresponding to the clean air carbon dioxide concentration under the same temperature and humidity conditions. The ratio of this zero-point correction value to the zero-air output signal value is calculated to obtain the signal response ratio, which is then written to the sensor's non-volatile memory unit. The signal response ratio is a fixed value, characterizing the proportional relationship between the clean air carbon dioxide concentration signal and the zero-air zero-point signal under the same temperature and humidity conditions.

[0074] The fourth stage involves performing on-site zero-point backtracking and calibration. When the sensor experiences zero-point drift during long-term operation and requires compensation, the sensor is placed in clean air, powered on, and preheated until the output stabilizes. The current temperature, humidity, and real-time output signal values ​​are then collected. These values ​​are substituted into an adjusted temperature and humidity fitting strategy to calculate the baseline signal value corresponding to the carbon dioxide concentration in the clean air at the current temperature and humidity. The ratio of the real-time output signal value to the baseline signal value is calculated to obtain the signal drift ratio. The real-time output signal value is divided by a pre-stored signal response ratio to calculate the true zero-point signal value corresponding to the zero-air environment at the current temperature and humidity. Subsequently, when normalizing the sensor output signal, the original output signal is multiplied by a preset normalization coefficient and then divided by the product of the true zero-point signal value and the signal drift ratio to obtain the calibrated normalized signal value, thus completing the zero-point backtracking and drift compensation for the carbon dioxide sensor.

[0075] In some embodiments, by adding a drift trend prediction and adaptive calibration triggering mechanism, the problem that a fixed calibration cycle cannot match the actual aging rate of the sensor is solved, further improving the balance between calibration efficiency and detection accuracy.

[0076] After each zero-point backtracking calibration, the sensor automatically records the timestamp of the calibration, the current temperature and humidity values, the calculated signal drift ratio, and the actual zero-point signal value, and stores them in the sensor's internal non-volatile storage unit to form a historical calibration dataset.

[0077] By using the accumulated historical calibration dataset as input and the signal drift ratio as output, the zero-point drift trend curve of the sensor is obtained through fitting calculation. The drift trend curve reflects the zero-point drift law of the sensor as the running time increases, and can predict the signal drift amplitude under different running times in the future.

[0078] During sensor operation, the drift trend prediction model is periodically invoked to predict the theoretical drift ratio corresponding to the current cumulative running time. When the predicted theoretical drift ratio exceeds the preset accuracy allowable threshold, a calibration reminder signal is automatically generated to prompt the operator to perform zero-point backtracking calibration. When the predicted theoretical drift ratio does not exceed the threshold, there is no need to perform full calibration; the output signal is directly fine-tuned and compensated based on the predicted drift ratio.

[0079] By completing each full zero-point backtracking calibration, the actual drift ratio obtained from this calibration is added to the historical dataset, and the drift trend curve is refitted and updated, so that the prediction accuracy gradually improves with the increase of the number of calibrations. For scenarios with large fluctuations in temperature and humidity in the operating environment, temperature and humidity parameters can be included in the prediction model to further improve the prediction accuracy.

[0080] In some embodiments, the signal calculation accuracy is optimized by using a multi-temperature and humidity range segmented fitting method, which solves the problem of large error of a single fitting strategy in a wide temperature and humidity environment, and is suitable for complex application scenarios such as extreme industrial environments and outdoor monitoring.

[0081] Based on the actual operating temperature and humidity range of the sensor, the temperature is divided into multiple continuous temperature sub-intervals, and the humidity is divided into multiple continuous humidity sub-intervals; each temperature sub-interval corresponds one-to-one with each humidity sub-interval, forming multiple non-overlapping temperature and humidity combination intervals.

[0082] During the factory calibration phase, calibration test points were selected in each temperature and humidity combination range, and calibration experiments were completed sequentially. For each temperature and humidity combination range, corresponding temperature fitting sub-strategy and humidity fitting sub-strategy were constructed, and the signal response ratio of the corresponding range was calibrated. The fitting sub-strategy and signal response ratio of all ranges were stored in the sensor storage unit according to the range number.

[0083] When performing zero-point backtracking on-site, the current temperature and humidity values ​​are first collected, the temperature and humidity combination range to which they belong is determined, and the temperature fitting sub-strategy, humidity fitting sub-strategy and signal response ratio corresponding to that range are called.

[0084] By using the interval corresponding parameters based on the call, the reference signal value, signal drift ratio, and true zero-point signal value of the clean air carbon dioxide concentration under the current temperature and humidity are calculated sequentially, and finally the normalization calibration of the output signal is completed.

[0085] In this embodiment, the fitting strategy for each temperature and humidity range is individually calibrated based on the signal change pattern of that range, avoiding the fitting error of a single fitting strategy across the entire temperature range, and significantly improving the zero-point backtracking accuracy under extreme low temperature, extreme high temperature and high humidity environments.

[0086] In some embodiments, by adding an effectiveness verification mechanism for the on-site calibration environment, the problem of unstable on-site clean air environment and susceptibility to external interference leading to calibration inaccuracies is solved, thereby improving the reliability of on-site calibration.

[0087] After entering the field calibration mode, the sensor continuously collects multiple sets of real-time output signal values, current temperature values, and current humidity values ​​at preset time intervals to form a continuous sampling dataset; the duration and number of samples in the sampling window can be preset according to the application scenario.

[0088] By performing fluctuation analysis on the continuously sampled dataset, the fluctuation amplitude, temperature change rate, and humidity change rate of the output signal value are calculated respectively. When the fluctuation amplitude of the output signal exceeds the preset signal threshold, or the temperature and humidity change rate exceeds the preset change threshold, it is determined that the current environment does not meet the clean air calibration requirements, and the sampling time is automatically extended and recalibrated.

[0089] The theoretical reference signal range under the current environment is calculated based on a temperature and humidity fitting strategy. The real-time output signal value is then compared with the theoretical reference signal range. If the real-time output signal value exceeds the theoretical reference signal range, it is determined that the current carbon dioxide concentration deviates from the normal atmospheric level and does not meet the calibration conditions. The operator is then prompted to change the calibration environment.

[0090] After multiple sets of sampled data have passed the stability and rationality checks, the average value of all valid sampled data is taken as the final real-time output signal value, current temperature value, and current humidity value, and then the subsequent zero-point backtracking calculation is performed.

[0091] This embodiment can effectively avoid calibration errors caused by on-site interference factors such as personnel approaching, gas source leakage, and direct airflow, ensuring that the input parameters for zero-point backtracking are accurate and reliable.

[0092] In some embodiments, by optimizing the factory calibration process and adopting a combination of batch benchmark calibration and single-point individual correction, the calibration efficiency of mass production of sensors can be significantly improved and production costs reduced while ensuring calibration accuracy.

[0093] By extracting a predetermined number of sample sensors from the same batch of sensors, a complete calibration of each sample sensor is performed across the entire temperature and humidity range. Temperature fitting strategies and humidity fitting strategies are constructed separately, and the signal response ratio across the entire temperature range is calibrated. The calibration results of all sample sensors are averaged to obtain the batch benchmark fitting strategy and batch benchmark signal response ratio of the sensors in that batch, which serve as the common benchmark parameters for all sensors in that batch.

[0094] For each mass-produced sensor in the same batch, single-point calibration is performed only under standard temperature and humidity conditions: the sensor is placed in a zero-air environment with standard temperature and humidity, and the zero-air output signal value is collected after power-on and stabilization; the standard temperature and humidity are substituted into the batch benchmark fitting strategy to calculate the theoretical zero-air signal value under standard temperature and humidity; the ratio of the actual zero-air output signal value to the theoretical zero-air signal value is calculated and used as the individual correction coefficient of the sensor, which is stored in the corresponding sensor's storage unit.

[0095] When performing zero-point backtracking on-site, the batch baseline fitting strategy and the batch baseline signal response ratio are first invoked to calculate the baseline calculation result; then the baseline calculation result is multiplied by the individual correction coefficient of the sensor to obtain the final true zero-point signal value and signal drift ratio, thus completing the normalization calibration.

[0096] This embodiment eliminates the need for full-temperature-range calibration of each sensor; single-point calibration is sufficient to correct individual differences, significantly reducing the factory calibration time for a single sensor while retaining the accuracy of full-temperature-range calibration. This makes it suitable for large-scale mass production scenarios.

[0097] Please see Figure 3 As shown, Figure 3 This is a schematic diagram of the structure of the carbon dioxide sensor zero-point backtracking device 200 provided in this application embodiment. The carbon dioxide sensor zero-point backtracking device 200 is used to execute the steps of the carbon dioxide sensor zero-point backtracking method shown in the above embodiments. The carbon dioxide sensor zero-point backtracking device 200 can be a single server or a server cluster, or it can be a terminal, such as a handheld terminal, a laptop computer, a wearable device, or a robot.

[0098] like Figure 3 As shown, the carbon dioxide sensor zero-point tracing device 200 includes: The parameter acquisition unit 201 is used to place the sensor to be processed in a preset zero-air environment and acquire the corresponding calibration sensor parameters after the sensor is powered on and preheated; the calibration sensor parameters include at least the calibration temperature value, the calibration humidity value, and the zero-air output signal value. The ratio calculation unit 202 is used to calculate the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters, and use the ratio of the zero-point correction value to the zero-air output signal value as the signal response ratio; the temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature change on infrared detection signal; the humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity. The drift compensation unit 203 is used to place the sensor in clean air, power it on and preheat it when the sensor has zero-point drift and needs compensation, and then collect the current sensor parameters of the sensor; the current sensor parameters include at least the current temperature value, the current humidity value and the real-time output signal value. The backtracking completion unit 204 is used to perform normalization calibration processing on the output signal collected by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters and the signal response ratio, and complete the zero-point backtracking of the sensor.

[0099] In some embodiments, the step of normalizing and calibrating the output signal acquired by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters, and the signal response ratio to complete the zero-point backtracking of the sensor includes: calculating the reference signal value of the carbon dioxide concentration corresponding to the clean air at the current temperature and humidity; calculating the ratio of the real-time output signal value to the reference signal value to obtain the signal drift ratio; calculating the true zero-point signal value corresponding to the zero-air environment at the current temperature and humidity according to the real-time output signal value and the signal response ratio; and performing normalization and calibration processing on the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio.

[0100] In some embodiments, calculating the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity based on the real-time output signal value and the signal response ratio includes: dividing the real-time output signal value by the signal response ratio to obtain the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity conditions.

[0101] In some embodiments, the normalization calibration process for the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio includes: multiplying the output signal value acquired by the sensor by a preset normalization coefficient, then dividing it by the product of the true zero-point signal value and the signal drift ratio, and outputting the calibrated normalized signal value.

[0102] In some embodiments, placing the sensor to be processed in a preset zero-gas environment and collecting the corresponding calibration sensor parameters after the sensor is powered on and preheated includes: placing the sensor to be processed in a nitrogen environment, and after the sensor has completed power-on and preheating, collecting the calibration temperature value, calibration humidity value and zero-gas output signal value output by the sensor respectively.

[0103] In some embodiments, the step of calculating the zero-point correction value of the carbon dioxide concentration in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters includes: calculating the temperature reference signal value corresponding to the calibration temperature value according to the temperature fitting strategy, calculating the humidity reference signal value corresponding to the calibration humidity value according to the humidity fitting strategy, and combining the temperature reference signal value and the humidity reference signal value to obtain the zero-point correction value of the carbon dioxide concentration in clean air.

[0104] In some embodiments, when the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, and after power-on preheating, the current sensor parameters are collected. This includes: when the sensor experiences zero-point drift and requires compensation, the sensor is placed in a clean air environment, and after the sensor has completed power-on preheating, the current temperature value, current humidity value, and real-time output signal value of the sensor are collected respectively.

[0105] It should be noted that those skilled in the art will understand that, for the sake of convenience and brevity, the specific working process of the carbon dioxide sensor zero-point backtracking device and its modules described above can be referred to the corresponding content in the various embodiments of the carbon dioxide sensor zero-point backtracking method, and will not be repeated here.

[0106] The aforementioned zero-point backtracking method for carbon dioxide sensors can be implemented as a computer program, which can be used in, for example... Figure 3 It runs on the device shown.

[0107] Please see Figure 4 , Figure 4 This is a schematic block diagram of the structure of a computer device provided in an embodiment of this application. The computer device includes a processor, a memory, and a network interface connected via a device bus, wherein the memory may include a storage medium and internal memory.

[0108] The storage medium can store operating devices and computer programs. The computer program includes program instructions that, when executed, cause the processor to perform any carbon dioxide sensor zero-point tracing method.

[0109] The processor provides computing and control capabilities, supporting the operation of the entire computer device.

[0110] The internal memory provides an environment for the execution of computer programs in non-volatile storage media. When the computer program is executed by the processor, it enables the processor to execute any carbon dioxide sensor zero-point backtracking method.

[0111] This network interface is used for network communication, such as sending assigned tasks. Those skilled in the art will understand that... Figure 4 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the terminal to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0112] It should be understood that the processor can be a Central Processing Unit (CPU), but it can also be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. Among these, a general-purpose processor can be a microprocessor or any conventional processor.

[0113] In one embodiment, the processor is configured to run a computer program stored in memory to perform the following steps: The sensor to be processed is placed in a preset zero-air environment. After the sensor is powered on and preheated, the corresponding calibration sensor parameters are collected. The calibration sensor parameters include at least the calibration temperature value, the calibration humidity value, and the zero-air output signal value. Based on the preset temperature fitting strategy, humidity fitting strategy, and the calibration sensor parameters, the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity is calculated, and the ratio of the zero-point correction value to the zero-air output signal value is used as the signal response ratio. The temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature changes on the infrared detection signal. The humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity. When the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, powered on and preheated, and then the current sensor parameters are collected; the current sensor parameters include at least the current temperature value, the current humidity value, and the real-time output signal value; Based on the temperature fitting strategy, humidity fitting strategy, current sensor parameters, and signal response ratio, the output signal acquired by the sensor is normalized and calibrated to complete the zero-point backtracking of the sensor.

[0114] In some embodiments, the step of normalizing and calibrating the output signal acquired by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters, and the signal response ratio to complete the zero-point backtracking of the sensor includes: calculating the reference signal value of the carbon dioxide concentration corresponding to the clean air at the current temperature and humidity; calculating the ratio of the real-time output signal value to the reference signal value to obtain the signal drift ratio; calculating the true zero-point signal value corresponding to the zero-air environment at the current temperature and humidity according to the real-time output signal value and the signal response ratio; and performing normalization and calibration processing on the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio.

[0115] In some embodiments, calculating the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity based on the real-time output signal value and the signal response ratio includes: dividing the real-time output signal value by the signal response ratio to obtain the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity conditions.

[0116] In some embodiments, the normalization calibration process for the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio includes: multiplying the output signal value acquired by the sensor by a preset normalization coefficient, then dividing it by the product of the true zero-point signal value and the signal drift ratio, and outputting the calibrated normalized signal value.

[0117] In some embodiments, placing the sensor to be processed in a preset zero-gas environment and collecting the corresponding calibration sensor parameters after the sensor is powered on and preheated includes: placing the sensor to be processed in a nitrogen environment, and after the sensor has completed power-on and preheating, collecting the calibration temperature value, calibration humidity value and zero-gas output signal value output by the sensor respectively.

[0118] In some embodiments, the step of calculating the zero-point correction value of the carbon dioxide concentration in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters includes: calculating the temperature reference signal value corresponding to the calibration temperature value according to the temperature fitting strategy, calculating the humidity reference signal value corresponding to the calibration humidity value according to the humidity fitting strategy, and combining the temperature reference signal value and the humidity reference signal value to obtain the zero-point correction value of the carbon dioxide concentration in clean air.

[0119] In some embodiments, when the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, and after power-on preheating, the current sensor parameters are collected. This includes: when the sensor experiences zero-point drift and requires compensation, the sensor is placed in a clean air environment, and after the sensor has completed power-on preheating, the current temperature value, current humidity value, and real-time output signal value of the sensor are collected respectively.

[0120] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, causes the processor to implement the steps of the carbon dioxide sensor zero-point backtracking method provided in any embodiment of this application.

[0121] The computer-readable storage medium may be an internal storage unit of the computer device described in the foregoing embodiments, such as the hard disk or memory of the computer device. The computer-readable storage medium may also be an external storage device of the computer device, such as a plug-in hard disk, SmartMedia Card (SMC), Secure Digital (SD) card, or Flash Card equipped on the computer device.

[0122] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A zero-point backtracking method for a carbon dioxide sensor, characterized in that, include: The sensor to be processed is placed in a preset zero-air environment, and the corresponding calibration sensor parameters are collected after the sensor is powered on and preheated. The calibrated sensor parameters include at least the calibrated temperature value, the calibrated humidity value, and the zero-air output signal value; Based on the preset temperature fitting strategy, humidity fitting strategy, and the calibration sensor parameters, the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity is calculated, and the ratio of the zero-point correction value to the zero-air output signal value is used as the signal response ratio. The temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature changes on the infrared detection signal. The humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity. When the sensor experiences zero-point drift and requires compensation, place the sensor in clean air, power it on and preheat it, and then collect the current sensor parameters. The current sensor parameters include at least the current temperature value, the current humidity value, and the real-time output signal value; Based on the temperature fitting strategy, humidity fitting strategy, current sensor parameters, and signal response ratio, the output signal acquired by the sensor is normalized and calibrated to complete the zero-point backtracking of the sensor.

2. The method according to claim 1, characterized in that, The step of normalizing and calibrating the output signal acquired by the sensor based on the temperature fitting strategy, humidity fitting strategy, current sensor parameters, and signal response ratio to complete the zero-point backtracking of the sensor includes: Calculate the baseline signal value of the carbon dioxide concentration in clean air at the current temperature and humidity; The signal drift ratio is obtained by calculating the ratio of the real-time output signal value to the reference signal value. Based on the real-time output signal value and the signal response ratio, calculate the actual zero-point signal value corresponding to the zero-air environment under the current temperature and humidity. Based on the true zero-point signal value and the signal drift ratio, the output signal acquired by the sensor is normalized and calibrated.

3. The method according to claim 2, characterized in that, The step of calculating the true zero-point signal value corresponding to the current zero-air environment under the current temperature and humidity based on the ratio of the real-time output signal value to the signal response includes: Divide the real-time output signal value by the signal response ratio to obtain the true zero-point signal value corresponding to the zero-air environment under the current temperature and humidity conditions.

4. The method according to claim 2, characterized in that, The normalization calibration process for the output signal acquired by the sensor based on the true zero-point signal value and the signal drift ratio includes: The output signal value acquired by the sensor is multiplied by a preset normalization coefficient, and then divided by the product of the true zero-point signal value and the signal drift ratio to output the calibrated normalized signal value.

5. The method according to claim 1, characterized in that, The step of placing the sensor to be processed in a preset zero-air environment and collecting the corresponding calibration sensor parameters after the sensor is powered on and preheated includes: The sensor to be processed was placed in a nitrogen environment. After the sensor was powered on and preheated, the calibrated temperature value, calibrated humidity value and zero gas output signal value were collected from the sensor.

6. The method according to claim 1, characterized in that, The step of calculating the zero-point correction value for the corresponding concentration of carbon dioxide in clean air under the same calibrated temperature and humidity, based on the preset temperature fitting strategy, humidity fitting strategy, and the calibrated sensor parameters, includes: The temperature reference signal value corresponding to the calibration temperature value is calculated based on the temperature fitting strategy. The humidity reference signal value corresponding to the calibrated humidity value is calculated based on the humidity fitting strategy; By combining the temperature reference signal value and the humidity reference signal value, the zero-point correction value for the corresponding concentration of carbon dioxide in clean air is obtained.

7. The method according to claim 1, characterized in that, When the sensor experiences zero-point drift and requires compensation, the sensor is placed in clean air, powered on, and preheated before its current sensor parameters are collected, including: When the sensor experiences zero-point drift and requires compensation, place the sensor in a clean air environment. After the sensor has completed power-on and preheating, collect the current temperature value, current humidity value, and real-time output signal value from the sensor.

8. A zero-point tracing device for a carbon dioxide sensor, characterized in that, The carbon dioxide sensor zero-point backtracking device is used to implement the method as described in any one of claims 1-7, comprising: The parameter acquisition unit is used to place the sensor to be processed in a preset zero-air environment and acquire the corresponding calibration sensor parameters after the sensor is powered on and preheated; the calibration sensor parameters include at least the calibration temperature value, the calibration humidity value, and the zero-air output signal value; The ratio calculation unit is used to calculate the zero-point correction value of the corresponding concentration of carbon dioxide in clean air under the same calibration temperature and humidity according to the preset temperature fitting strategy, humidity fitting strategy and the calibration sensor parameters, and use the ratio of the zero-point correction value to the zero-air output signal value as the signal response ratio; the temperature fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple temperature points, which is used to quantify the drift effect of temperature change on infrared detection signal; the humidity fitting strategy is a second-order polynomial correction model obtained by fitting zero-air calibration data at multiple humidity points, which is used to quantify the interference effect of water vapor absorption on infrared light intensity. The drift compensation unit is used to place the sensor in clean air, power it on and preheat it when the sensor experiences zero-point drift and needs compensation, and then collect the current sensor parameters; the current sensor parameters include at least the current temperature value, the current humidity value and the real-time output signal value. The backtracking completion unit is used to perform normalization calibration processing on the output signal collected by the sensor according to the temperature fitting strategy, humidity fitting strategy, the current sensor parameters and the signal response ratio, and complete the zero-point backtracking of the sensor.

9. A computer device, characterized in that, Including memory and processor; The memory is used to store computer programs; The processor is configured to execute the computer program and, in executing the computer program, implement the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, causes the processor to implement the method as described in any one of claims 1 to 7.

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