Linear closed-loop optimization method for semiconductor gas sensor with adjustable voltage dynamic compensation

Abstract

The invention discloses a linearity closed-loop optimization method for a semiconductor gas sensor with adjustable voltage dynamic compensation, which relates to the technical field of gas detection and comprises the following steps: controlling the semiconductor gas sensor to start in a clean air environment, outputting an initial test voltage sequence through a voltage regulator, the method comprises the steps of collecting sensor reference resistance under different voltages, screening out initial working voltage with the minimum resistance fluctuation quantity, synchronously collecting initial environment temperature and humidity, and calibrating the sensor reference resistance based on preset temperature and resistance coefficients and humidity and resistance coefficients to obtain initial reference resistance. By dynamically adjusting the working voltage and combining real-time compensation on the environment temperature and humidity, the interference of environment factor fluctuation on the resistance characteristic of the sensitive material can be continuously counteracted, so that the linear relation between the output signal of the sensor and the target gas concentration is kept stable, the dynamic optimization of the linearity in a complex environment is realized, and the sensitivity of the sensor is improved. And more reliable basic data is provided for gas concentration detection in an industrial scene.

Description

Technical Field

[0001] This invention relates to the field of gas detection technology, specifically to a closed-loop optimization method for the linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation. Background Technology

[0002] Semiconductor gas sensors are devices that use metal oxide semiconductors as sensitive elements to analyze the composition or concentration of gases by detecting changes in conductivity caused by gas adsorption. The core principle is that when gas molecules are adsorbed on the semiconductor surface, an oxidation / reduction reaction is triggered, which leads to a change in the material's conductivity. For example, reducing gases react with adsorbed oxygen, lowering the surface barrier and causing the sensor's resistance to decrease, thus enabling gas detection.

[0003] Existing semiconductor gas sensors generally use a fixed operating voltage. This is because fluctuations in ambient temperature can change the chemical reaction rate of the sensitive material, changes in humidity can cause a shift in the hygroscopic resistance of the material, and long-term use can cause material aging to change the structure of the sensitive layer. As a result, the linear relationship between the sensor output signal and the target gas concentration is continuously disrupted, causing nonlinear deviations in the signal during detection over a wide concentration range. These deviations gradually increase with the duration of use, making it impossible to meet the requirements for high-precision and long-term stable monitoring in industrial environments. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a closed-loop optimization method for the linearity of semiconductor gas sensors with adjustable voltage dynamic compensation, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a closed-loop optimization method for the linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation, comprising the following steps: A1. Control the semiconductor gas sensor to start in a clean air environment, output the initial test voltage sequence through the voltage regulator, collect the sensor reference resistance under different voltages, select the initial working voltage with the smallest resistance fluctuation, and simultaneously collect the initial ambient temperature and humidity. Based on the preset temperature and resistivity and humidity and resistivity, calibrate the sensor reference resistance to obtain the initial reference resistance. A2. After calibration, continuously collect the real-time resistance, ambient temperature, ambient humidity and target gas concentration change rate of the semiconductor gas sensor in the target gas environment, calculate the real-time resistance change, and record the current operating voltage of the semiconductor gas sensor. A3. Based on the linear relationship between the real-time resistance change and the initial reference resistance, the current linearity deviation is calculated using a linear fitting algorithm. When the linearity deviation exceeds the preset threshold, the temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage are calculated respectively. A4. Based on linearity deviation and temperature compensation voltage, humidity compensation voltage and material aging compensation voltage, calculate the total voltage adjustment through closed-loop control algorithm, output the adjusted voltage, and update the reference resistor to the calibration value under the current voltage. A5. Dynamically adjust the data acquisition cycle according to the gas concentration change rate to achieve high and low speed sampling mode switching, continuously cycle through steps A2 to A4, monitor linearity deviation in real time and dynamically correct the working voltage until the linearity deviation stabilizes within the preset threshold.

[0006] Preferably, the method for generating and filtering the initial test voltage sequence in step A1 is as follows: A11. Generate a voltage sequence of 0.5V to 5V in step size of 0.1V, and after each voltage point is kept stable for 30s, continuously collect the reference resistance of the semiconductor gas sensor 10 times. A12. Calculate the standard deviation of resistance under a single voltage test, and select the standard deviation of resistance as: The voltage is used as the initial operating voltage; in, For the standard deviation of resistance, The value is the average of 10 measurements of the reference resistor for the semiconductor gas sensor.

[0007] Preferably, the linear fitting algorithm in step A3 is as follows: A linear model is established using the real-time resistance change as the dependent variable and the initial reference resistance as the independent variable:

[0008] in, As the dependent variable, As the independent variable, and These are the fitting parameters; The fitting parameters are specifically:

[0009]

[0010] in, The number of data sets to fit, ranging from 5 to 10. ≤10; Therefore, the linearity deviation of the gas sensor is specifically as follows:

[0011] in, The slope of the target linearity.

[0012] Preferably, the closed-loop control algorithm in step A4 is a PID control algorithm, specifically, the formula for calculating the total voltage adjustment is:

[0013] in, This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... For linearity deviation, These are the temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage, respectively.

[0014] Preferably, the adaptive adjustment method for the sampling period in step A5 is as follows: when When the sampling period is set to 5-10 seconds, When switching, the sampling period is switched to 0.5 to 1 second, and the current state is saved through the data buffer to ensure continuity during the switching. in, This represents the instantaneous change in the concentration of the target gas. For the corresponding concentration change The tiny time interval experienced is measured in seconds (s).

[0015] Preferably, step A5 further includes a linearity anomaly early warning method: When linearity deviation A Level 1 alert is triggered, and only abnormal data is recorded and stored. When linearity deviation When a level-two warning is triggered, the local audible and visual alarm will be activated. When linearity deviation When a Level 3 warning is triggered, the warning information is transmitted wirelessly.

[0016] Preferably, the local audible and visual alarm includes: a buzzer sounding and an alarm indicator light flashing; The warning information includes: sensor device ID, abnormal time, and real-time parameters.

[0017] Preferably, the method for collecting and processing real-time humidity in step A2 is as follows: A humidity sensor is integrated into the semiconductor gas sensor to synchronously collect ambient humidity. A moving average algorithm is used for filtering, with a filtering window of 3-5 sets of data. The filtered data is then used to calculate the humidity compensation voltage.

[0018] Preferably, step A5 further includes a closed-loop adjustment state recording method: After each voltage adjustment is completed, the system automatically records the execution time of the adjustment operation, the working voltage values ​​before and after the adjustment, and the linearity deviation at the corresponding moment. The recorded content is stored in non-volatile memory in chronological order, and the storage period is consistent with the actual working period of the sensor.

[0019] Preferably, step A4 further includes a voltage regulation safety limit method: When the absolute value of the calculated total voltage adjustment exceeds 30% of the initial operating voltage, the actual voltage adjustment is limited to 30% of the initial operating voltage. At the same time, the adjustment is marked as a restricted state, and environmental parameters are collected first in the subsequent real-time monitoring phase to reassess the linearity deviation.

[0020] This invention provides a closed-loop optimization method for the linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation. It offers the following advantages: (1) By dynamically adjusting the working voltage and combining it with real-time compensation for ambient temperature and humidity, it can continuously offset the interference of environmental factors on the resistance characteristics of sensitive materials, so that the linear relationship between the sensor output signal and the target gas concentration remains stable, realizing the dynamic optimization of linearity in complex environments, and thus providing more reliable basic data for gas concentration detection in industrial scenarios, meeting the needs of high-precision monitoring.

[0021] (2) By continuously updating the reference resistor and dynamically correcting the working voltage through the closed-loop mechanism, it can effectively cope with the changes in the sensitive layer structure caused by aging during long-term use of materials, alleviate the continuous deterioration of the linear relationship, realize the performance stability of the sensor throughout its entire life cycle, thereby reducing the need for frequent calibration or equipment replacement due to excessive linearity deviation and reducing long-term use costs.

[0022] (3) Through continuous cyclic monitoring and real-time adjustment, the sampling mode can be dynamically adapted according to the gas concentration change, ensuring that the linear detection state can still be maintained when the concentration fluctuates rapidly. This achieves adaptive response to different concentration change scenarios, thereby meeting the dual requirements of real-time and accuracy of gas detection in industrial environments and improving the overall reliability of the monitoring system. Attached Figure Description

[0023] Figure 1 This is a flowchart of the closed-loop optimization method for the linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to the present invention. Figure 2 This diagram illustrates the steps of the adjustable voltage dynamic compensation method for linearity closed-loop optimization of semiconductor gas sensors according to the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] Example 1 Please see Figure 1-2 This invention provides a closed-loop optimization method for the linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation. To achieve the above objectives, this invention is implemented through the following technical solution, including the following steps: A1. Control the semiconductor gas sensor to start in a clean air environment, output the initial test voltage sequence through the voltage regulator, collect the sensor reference resistance under different voltages, select the initial working voltage with the smallest resistance fluctuation, and simultaneously collect the initial ambient temperature and humidity. Based on the preset temperature and resistivity and humidity and resistivity, calibrate the sensor reference resistance to obtain the initial reference resistance. A2. After calibration, continuously collect the real-time resistance, ambient temperature, ambient humidity and target gas concentration change rate of the semiconductor gas sensor in the target gas environment, calculate the real-time resistance change, and record the current operating voltage of the semiconductor gas sensor. A3. Based on the linear relationship between the real-time resistance change and the initial reference resistance, the current linearity deviation is calculated using a linear fitting algorithm. When the linearity deviation exceeds the preset threshold, the temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage are calculated respectively. A4. Based on linearity deviation and temperature compensation voltage, humidity compensation voltage and material aging compensation voltage, calculate the total voltage adjustment through closed-loop control algorithm, output the adjusted voltage, and update the reference resistor to the calibration value under the current voltage. A5. Dynamically adjust the data acquisition cycle according to the gas concentration change rate to achieve high and low speed sampling mode switching, continuously cycle through steps A2 to A4, monitor linearity deviation in real time and dynamically correct the working voltage until the linearity deviation stabilizes within the preset threshold.

[0026] In this embodiment, after the sensor is started in a clean air environment, the voltage regulator outputs a series of test voltages according to preset rules. Each voltage value remains stable for a period of time. During this period, the reference resistance of the sensor is continuously collected. By comparing the stability of the resistance under different voltages, the voltage with the smallest resistance fluctuation is selected as the initial working voltage. At the same time, the ambient temperature and humidity are recorded. Based on the influence of temperature and humidity on resistance as specified before the sensor leaves the factory, the reference resistance is calibrated to obtain the reference resistance value in the initial state, thus establishing a reference benchmark for subsequent testing.

[0027] After the sensor enters the target gas environment, it continuously monitors its real-time resistance change. At the same time, it obtains the current temperature, humidity, and rate of change of the target gas concentration through the integrated environmental sensor, calculates the difference between the real-time resistance and the initial reference resistance as a key parameter reflecting the gas concentration, and records the sensor's current operating voltage to provide a basis for subsequent adjustments. Based on the linear relationship between the real-time resistance change and the initial reference resistance, the current linearity deviation is evaluated by analyzing the correspondence between the two. When the deviation exceeds the preset acceptable range, the voltage value to be compensated is calculated for changes in ambient temperature, humidity fluctuations, and material aging caused by long-term use of the sensor. The calculation of these compensation values ​​is based on the correlation between temperature, humidity, aging degree, and resistance change determined through previous experiments. By combining linearity deviation and various compensation voltages, the total voltage that needs to be adjusted is calculated through closed-loop control logic. Then, the adjusted voltage is output to the sensor, and the reference resistor at this time is updated to the calibration value under this voltage, ensuring that subsequent detection is always based on the current state, forming a dynamic feedback closed loop.

[0028] Based on the rate of change of the target gas concentration, the data acquisition frequency is automatically adjusted. When the concentration change is slow, the sampling frequency is reduced to reduce energy consumption. When the concentration change is drastic, the sampling frequency is increased to ensure the real-time performance of the data. During this process, the second to fourth steps above are repeated continuously, and the linearity deviation is continuously monitored and the working voltage is adjusted until the deviation stabilizes within the preset range, ensuring that the sensor output signal and the gas concentration maintain a stable linear relationship.

[0029] Through phased system initialization, real-time monitoring, and dynamic adjustment, the system achieves real-time response to changes in environmental factors and the sensor's own state, enabling the sensor to maintain stable linear output characteristics in complex industrial environments. This provides a reliable guarantee for high-precision gas concentration detection, and is especially suitable for chemical and mining scenarios with high safety requirements.

[0030] Example 2 Specifically: See reference Figure 1 The specific method for generating and filtering the initial test voltage sequence in step A1 is as follows: A11. Generate a voltage sequence of 0.5V to 5V in step size of 0.1V, and after each voltage point is kept stable for 30s, continuously collect the reference resistance of the semiconductor gas sensor 10 times. A12. Calculate the standard deviation of resistance under a single voltage test, and select the standard deviation of resistance as: The voltage is used as the initial operating voltage; in, For the standard deviation of resistance, The value is the average of 10 measurements of the reference resistor for the semiconductor gas sensor.

[0031] The linear fitting algorithm in step A3 is as follows: A linear model is established using the real-time resistance change as the dependent variable and the initial reference resistance as the independent variable:

[0032] in, As the dependent variable, As the independent variable, and These are the fitting parameters; The fitting parameters are as follows:

[0033]

[0034] in, The number of data sets to fit, ranging from 5 to 10. ≤10; Therefore, the linearity deviation of the gas sensor is specifically as follows:

[0035] in, The slope of the target linearity.

[0036] The method for collecting and processing real-time humidity in step A2 is as follows: A humidity sensor is integrated into the semiconductor gas sensor to synchronously collect ambient humidity. The data is filtered using a moving average algorithm with a filtering window of 3-5 sets of data. The filtered data is then used to calculate the humidity compensation voltage. In this embodiment, the voltage regulator generates a series of voltage values ​​from low to high in fixed small steps, covering the normal operating voltage range of the sensor. After each voltage value is output, the sensor needs to go through a stabilization period. After the resistance value stabilizes, the reference resistance is continuously sampled multiple times. By calculating the dispersion of the multiple resistance measurements under the same voltage, the voltage with the smallest dispersion is selected as the initial operating voltage. This process ensures that the sensor operates in the most stable voltage state from the start-up stage, reducing the impact of initial errors on subsequent detection. In real-time detection, the correspondence between the real-time resistance change of the sensor and the initial reference resistance is continuously recorded. Multiple sets of continuous corresponding data are selected, and the distribution pattern of these data is analyzed to evaluate the degree of linear matching between the two. When the degree of linear matching deviates from the preset ideal state, it is determined that the linearity deviation exceeds the threshold, triggering the subsequent compensation mechanism. Ambient humidity is collected synchronously by an integrated humidity sensor. To reduce the impact of instantaneous fluctuations on humidity data, the average value is taken after multiple consecutive collections for filtering. The filtered humidity data is used for subsequent calculation of humidity compensation voltage to ensure that the influence of humidity on sensor resistance is accurately corrected and to avoid detection deviation caused by sudden changes in humidity. By refining the initial voltage screening process, the stability of the sensor's operating point was ensured; by simplifying the execution logic of linear relationship evaluation, the efficiency of deviation judgment was improved; and by optimizing the acquisition and processing of humidity data, environmental adaptability was enhanced. The synergistic effect of these three factors enabled the sensor to maintain a stable linear output in the detection of low-concentration methane, meeting the accuracy requirements for civil gas leak detection.

[0037] Example 3 Specifically: See reference Figure 1 In step A4, the closed-loop control algorithm is a PID control algorithm. Specifically, the formula for calculating the total voltage adjustment is:

[0038] in, This is the proportionality coefficient. The integral coefficient is... The differential coefficients are... For linearity deviation, These are the temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage, respectively.

[0039] Step A4 also includes a voltage regulation safety limit method: When the absolute value of the calculated total voltage adjustment exceeds 30% of the initial operating voltage, the actual voltage adjustment will be limited to 30% of the initial operating voltage. At the same time, the adjustment will be marked as a restricted state, and environmental parameters will be collected first in the subsequent real-time monitoring phase to re-evaluate the linearity deviation. In this embodiment, when the linearity deviation exceeds a threshold, the semiconductor gas sensor system comprehensively considers the current degree of linearity deviation, as well as the compensation voltages corresponding to temperature, humidity, and material aging. It calculates the total voltage adjustment required through preset closed-loop control logic. The proportional element is used to quickly respond to the current deviation, the integral element is used to eliminate long-term accumulated deviations, and the derivative element is used to suppress fluctuations during the adjustment process. These three elements work together to achieve smooth voltage adjustment. The adjusted voltage is output to the sensor in real time, and the reference resistor is updated to the calibration value at that voltage, forming a complete feedback closed loop. To avoid damage to the sensor's sensitive materials caused by drastic voltage fluctuations, a maximum allowable adjustment range is set. When the calculated total voltage adjustment exceeds this range, the actual adjustment will be limited to the maximum allowable range, and the adjustment will be marked as restricted. In subsequent detection processes, the system will prioritize collecting environmental parameters and sensor status data to reassess the cause of linearity deviation. Further adjustments will only be made after safety is confirmed. This mechanism ensures the physical safety of the sensor during dynamic adjustment and avoids material performance degradation caused by over-adjustment. The closed-loop control logic achieves the accuracy and stability of voltage adjustment through multi-stage collaboration. It can quickly correct linearity deviations and avoid oscillations during the adjustment process. The safety limiting mechanism provides physical protection for the sensor and extends the service life of the device. It is especially suitable for industrial waste gas monitoring scenarios that require long-term continuous operation. The specific formulas for calculating temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage are as follows: The calculation method for temperature compensation voltage is as follows:

[0040] in, The temperature coefficient is obtained by measuring the sensor's temperature in clean air. and resistance at time and Based on the Boltzmann equation fitting, we obtain:

[0041] The calculation method for humidity compensation voltage is as follows:

[0042] in, The humidity coefficient is determined using the following method: under constant temperature conditions of 25℃ and a gas concentration of 0ppm, samples were collected... , , and Changes in resistance in the environment The linear regression equation yields:

[0043] The value range is 0.001~0.003 / (%RH); The calculation method for material aging compensation voltage is as follows:

[0044] in, To predict the resistance, it is calculated based on an exponential decay model, specifically:

[0045] Aging coefficient Data collected at midnight every day The data is updated using the least squares method for fitting. The cumulative number of working days for the sensor; Temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage are the core correction quantities for offsetting multi-factor interference in this linearity closed-loop optimization method. The three work together to maintain the stability of sensor linearity and together serve as components of the total voltage adjustment. In the closed-loop control, the operating voltage is corrected in real time to ensure that the sensor maintains a stable linear output under complex conditions such as temperature fluctuations, humidity changes, and material aging.

[0046] Example 4 Specifically: See reference Figure 1 The adaptive adjustment method for the sampling period in step A5 is as follows: when When the sampling period is set to 5-10 seconds, When switching, the sampling period is switched to 0.5 to 1 second, and the current state is saved through the data buffer to ensure continuity during the switching. in, This represents the instantaneous change in the concentration of the target gas. For the corresponding concentration change The tiny time interval experienced is measured in seconds (s).

[0047] Step A5 also includes a linearity anomaly early warning method: When linearity deviation A Level 1 alert is triggered, and only abnormal data is recorded and stored. When linearity deviation When a level-two warning is triggered, the local audible and visual alarm will be activated. When linearity deviation When a Level 3 warning is triggered, the warning information is transmitted wirelessly.

[0048] Local audible and visual alarms include: a buzzer sound and a flashing alarm indicator light; The warning information includes: sensor device ID, abnormal time, and real-time parameters.

[0049] Step A5 also includes a closed-loop adjustment state recording method: After each voltage adjustment is completed, the execution time of the adjustment operation, the working voltage value before and after the adjustment, and the linearity deviation status at the corresponding moment are automatically recorded. The recorded content is stored in non-volatile memory in chronological order, and the storage period is consistent with the actual working period of the sensor. In this embodiment, The system continuously monitors the rate of change of the target gas concentration. When the concentration change is gradual, it automatically switches to a low-speed sampling mode to extend the data acquisition interval and reduce unnecessary energy consumption. When the concentration change accelerates, it immediately switches to a high-speed sampling mode to shorten the acquisition interval and ensure the capture of rapid concentration changes. During mode switching, the system saves the current detection status and acquired data through a data buffer. After the switch is completed, it resumes acquisition from the breakpoint to ensure the continuity and integrity of the data sequence and avoid information loss due to mode switching. The system sets up a three-level early warning mechanism based on the severity of linearity deviation: when the deviation slightly exceeds the threshold, the abnormal information is only recorded in the storage unit for subsequent maintenance and analysis; when the deviation further increases, a local audible and visual alarm is activated, alerting on-site personnel to conduct an inspection through sound prompts and flashing lights; when the deviation seriously exceeds the standard, the abnormal information is uploaded to the remote monitoring platform through the wireless communication module, including the equipment identification, the time of the abnormality, and the current environmental parameters, so that remote maintenance personnel can intervene and handle it in a timely manner. The adaptive adjustment of the sampling cycle balances real-time detection with energy consumption control, making it suitable for battery-powered portable devices. The graded early warning mechanism achieves gradient management of abnormal risks through differentiated response methods, avoiding overreaction to minor anomalies while ensuring timely handling of serious anomalies, thus providing multi-layered safety assurance for gas monitoring in high-risk environments.

[0050] Specifically, the initial calibration begins with the sensor starting in a clean air environment. A series of test voltages are output through a voltage regulator to select the initial operating voltage with the smallest resistance fluctuation. Initial temperature and humidity are collected simultaneously, and the reference resistor is calibrated based on the preset influence of temperature and humidity on resistance to establish an initial reference. Next, real-time monitoring begins, with the sensor continuously collecting its own real-time resistance, ambient temperature and humidity, and the rate of change of the target gas concentration. The difference between the real-time resistance and the initial reference resistance is calculated, and the current operating voltage is recorded. Then, linearity is evaluated, and the deviation is judged based on the linear relationship between the resistance change and the reference resistance to determine whether it exceeds the threshold. If it exceeds the threshold, the compensation voltage corresponding to temperature, humidity, and material aging is calculated respectively. Then, the total voltage adjustment is calculated through closed-loop control, the adjusted voltage is output, and the reference resistance is updated to form dynamic feedback. Finally, adaptive optimization is performed, switching between high and low speed sampling modes according to the rate of change of gas concentration, continuously monitoring and adjusting until the linearity deviation stabilizes within the preset threshold, achieving long-term stability of the sensor's linearity in complex environments.

[0051] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention.

Claims

1. A closed-loop optimization method for the linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation, characterized in that: Includes the following steps: A1. Control the semiconductor gas sensor to start in a clean air environment, output the initial test voltage sequence through the voltage regulator, collect the sensor reference resistance under different voltages, select the initial working voltage with the smallest resistance fluctuation, and simultaneously collect the initial ambient temperature and humidity. Based on the preset temperature and resistivity and humidity and resistivity, calibrate the sensor reference resistance to obtain the initial reference resistance. A2. After calibration, continuously collect the real-time resistance, ambient temperature, ambient humidity and target gas concentration change rate of the semiconductor gas sensor in the target gas environment, calculate the real-time resistance change, and record the current operating voltage of the semiconductor gas sensor. A3. Based on the linear relationship between the real-time resistance change and the initial reference resistance, the current linearity deviation is calculated using a linear fitting algorithm. When the linearity deviation exceeds the preset threshold, the temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage are calculated respectively. A4. Based on linearity deviation and temperature compensation voltage, humidity compensation voltage and material aging compensation voltage, calculate the total voltage adjustment through closed-loop control algorithm, output the adjusted voltage, and update the reference resistor to the calibration value under the current voltage. A5. Dynamically adjust the data acquisition cycle according to the gas concentration change rate to achieve high and low speed sampling mode switching, continuously cycle through steps A2 to A4, monitor linearity deviation in real time and dynamically correct the working voltage until the linearity deviation stabilizes within the preset threshold.

2. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: The specific method for generating and filtering the initial test voltage sequence in step A1 is as follows: A11. Generate a voltage sequence of 0.5V to 5V in step size of 0.1V, and after each voltage point is kept stable for 30s, continuously collect the reference resistance of the semiconductor gas sensor 10 times. A12. Calculate the standard deviation of resistance under a single voltage test, and select the standard deviation of resistance as: The voltage is used as the initial operating voltage; in, For the standard deviation of resistance, The value is the average of 10 measurements of the reference resistor for the semiconductor gas sensor.

3. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: The linear fitting algorithm in step A3 is as follows: A linear model is established using the real-time resistance change as the dependent variable and the initial reference resistance as the independent variable: ； in, As the dependent variable, As the independent variable, and These are the fitting parameters; The fitting parameters are specifically: ； ； in, The number of data sets to fit, ranging from 5 to 10. ≤10; Therefore, the linearity deviation of the gas sensor is specifically as follows: ； in, The slope of the target linearity.

4. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: The closed-loop control algorithm in step A4 is a PID control algorithm. Specifically, the formula for calculating the total voltage adjustment is: ； in, This is the proportionality coefficient. The integral coefficient is... These are the differential coefficients. For linearity deviation, These are the temperature compensation voltage, humidity compensation voltage, and material aging compensation voltage, respectively.

5. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: The adaptive adjustment method for the sampling period in step A5 is as follows: when When the sampling period is set to 5-10 seconds, When switching, the sampling period is switched to 0.5 to 1 second, and the current state is saved through the data buffer to ensure continuity during the switching. in, This represents the instantaneous change in the concentration of the target gas. For the corresponding concentration change The tiny time interval experienced is measured in seconds (s).

6. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: Step A5 also includes a linearity anomaly early warning method: When linearity deviation A Level 1 alert is triggered, and only abnormal data is recorded and stored. When linearity deviation When a level-two warning is triggered, the local audible and visual alarm will be activated. When linearity deviation When a Level 3 warning is triggered, the warning information is transmitted wirelessly.

7. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 6, characterized in that: The local audible and visual alarm includes: a buzzer sounding and an alarm indicator light flashing; The warning information includes: sensor device ID, abnormal time, and real-time parameters.

8. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: The method for collecting and processing real-time humidity in step A2 is as follows: A humidity sensor is integrated into the semiconductor gas sensor to synchronously collect ambient humidity. The data is filtered using a moving average algorithm with a filtering window of 3-5 sets of data. The filtered data is then used to calculate the humidity compensation voltage.

9. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: Step A5 also includes a closed-loop adjustment state recording method: After each voltage adjustment is completed, the system automatically records the execution time of the adjustment operation, the working voltage values ​​before and after the adjustment, and the linearity deviation at the corresponding moment. The recorded content is stored in non-volatile memory in chronological order, and the storage period is consistent with the actual working period of the sensor.

10. The closed-loop optimization method for linearity of a semiconductor gas sensor with adjustable voltage dynamic compensation according to claim 1, characterized in that: Step A4 also includes a voltage regulation safety limitation method: When the absolute value of the calculated total voltage adjustment exceeds 30% of the initial operating voltage, the actual voltage adjustment is limited to 30% of the initial operating voltage. At the same time, the adjustment is marked as a restricted state, and environmental parameters are collected first in the subsequent real-time monitoring phase to reassess the linearity deviation.

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