A gas detection method and device based on multi-sensor combination

Abstract

The present invention relates to the field of gas detection, and discloses a gas detection method and device based on a multi-sensor combination. The method includes constructing a multi-sensor combination and obtaining its output value. The multi-sensor combination includes a first sensor and a second sensor. Among them, the output values of the first sensor and the second sensor both include a first gas value and / or a second gas value. The first sensor and the second sensor are both configured to have a linear response to any one of the first gas and the second gas. The first sensor and the second sensor are configured as sensors with different detection principles. Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor. The present invention solves the problem that in the prior art, when detecting the first gas, due to the influence of the second gas, the output result of the sensor is inaccurate.

Description

Technical Field

[0001] The present invention relates to the field of gas detection, and in particular to a gas detection method and device based on a multi-sensor combination. Background Art

[0002] The application fields of gas detection are very extensive, including industrial production, environmental protection, medical diagnosis, etc. In industrial production, gas detection is used to monitor the emission of harmful gases to ensure the safety of the working environment; in environmental protection, it is used to detect pollutants in the atmosphere; in medical diagnosis, it is used to detect the components of respiratory gases to assist in disease diagnosis.

[0003] Existing sensors for gas detection often only measure the refrigerant gas to be detected; taking sensors for detecting refrigerant gas as an example, such as patent applications: DE202023103907U1 for refrigerant gas leakage detection sensor, CN116930270A gas detection probe, CN118392948A gas sensor, etc., all detect a single refrigerant gas to be detected. The above measurements ignore the influence of certain specific interfering gases on the gas detection sensor. When there are certain specific interfering gases, since the gas detection sensor will respond to the interfering gas, the measured value output by it may be biased. Summary of the Invention

[0004] The purpose of the present invention is to propose a gas detection method and device based on a multi-sensor combination to solve the above technical problems.

[0005] Specifically, a gas detection method based on a multi-sensor combination provided by the present invention includes the following steps: S1: Construct a multi-sensor combination and obtain its output value; the multi-sensor combination includes: a first sensor and a second sensor; wherein, the output values of the first sensor and the second sensor both include a first gas value and a second gas value; both the first sensor and the second sensor are configured to have a linear response to any one of the first gas and the second gas; the first sensor and the second sensor are configured as sensors with different detection principles; S2: Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor.

[0006] The present invention also provides a gas detection device based on a multi-sensor combination, comprising: a first sensor, a second sensor, and a controller; the first sensor and the second sensor are configured to output values, and each output value includes a first gas value and / or a second gas value; the first sensor and the second sensor are both configured to have a linear response to any one of a first gas and a second gas; the first sensor and the second sensor are configured to be sensors with different detection principles; the controller executes the steps of the above-mentioned gas detection method based on a multi-sensor combination.

[0007] The beneficial effects provided by the present invention are as follows: at least the output of the concentrations of the first gas and / or the second gas can be achieved. Therefore, when the target gas to be detected by the sensor is affected by a certain interfering gas, through the present invention, the target gas and the interfering gas can be respectively used as the first gas and the second gas, and then the value of the target gas output can be ensured not to have an error due to the presence of the interfering gas; in addition, when two gases need to be detected, the present invention can also be used to directly output the concentration values of the two gases. Description of the Drawings

[0008] Figure 1 is a schematic flowchart of the method of the present invention;

[0009] Figure 2 is a schematic flowchart of step S2 in the first case of the present invention;

[0010] Figure 3 is a schematic flowchart of step S2 in the second case of the present invention;

[0011] Figure 4 is a schematic flowchart of step S2 in the third case of the present invention;

[0012] Figure 5 is a schematic flowchart of step S2 in the fourth case of the present invention;

[0013] Figure 6 is a schematic diagram of the detection process in the first case after adding a humidity sensor;

[0014] Figure 7 is a schematic diagram of the detection process in the second case after adding a humidity sensor;

[0015] Figure 8 is a coordinate diagram showing the change of the respective first gas values of the first sensor and the second sensor with the concentration of the first gas;

[0016] Figure 9 is a schematic diagram of the device of the present invention. Detailed Embodiments

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0018] Before formally elaborating on the present invention, a general overview of the solution of the present invention will be provided first for easier understanding.

[0019] Please refer to Figure 1 , Figure 1 which is a schematic diagram of the method flow of the present invention.

[0020] The present invention provides a gas detection method based on a multi-sensor combination, including the following steps:

[0021] S1: Construct a multi-sensor combination and obtain its output value; the multi-sensor combination includes: a first sensor and a second sensor; wherein, the output values of the first sensor and the second sensor both include a first gas value and a second gas value;

[0022] It should be noted that, actually, only one value is output by the first or second sensor, but this output value may contain the first gas value and / or the second gas value, rather than meaning that the sensor output value includes two numerical values. More precisely, it is the variable generated by the first or second sensor affected by the first gas and / or the variable generated by the second gas. For the convenience of explanation, in the present invention, these two variables are respectively referred to as the first gas value and the second gas value.

[0023] It should be particularly noted that, in the embodiments of the present invention, the first gas refers to the gas to be detected, and the second gas refers to the interfering gas. Of course, in some other embodiments, the reference order can also be replaced.

[0024] Based on the above concept, if there is only the gas to be detected in the gas chamber, only the value of the gas to be detected is output by the first and second sensors; if there is only the interfering gas in the gas chamber, only the value of the interfering gas is output by the first and second sensors; if there are both the gas to be detected and the interfering gas in the gas chamber, the values output by the first and second sensors are the combined values of the interfering gas and the gas to be detected.

[0025] It should be added that, in some other embodiments, both the first gas and the second gas can also be the target gases to be detected.

[0026] Both the first sensor and the second sensor are configured to have a linear response to any one of the first gas and the second gas; it should be noted that the linear response specifically means: when the gas concentration changes, the corresponding response of the sensor also changes linearly and proportionally.

[0027] The first sensor and the second sensor are configured as sensors with different detection principles;

[0028] Regarding the detection principle of the sensor, it means that the sensor can sense the information of the measured quantity and convert it into an electrical signal or other required form of information output according to a certain rule to meet the requirements of information transmission, processing, and control, etc.

[0029] It should be noted that in this embodiment, the first sensor is taken as an ultrasonic sensor and the second sensor is taken as a thermal conductivity sensor as an example for illustration. In other embodiments, as long as the above limitations on the first sensor and the second sensor are met, the present application does not limit the actual detection principle of the sensor.

[0030] Ultrasonic sensor:

[0031] The ultrasonic gas sensing technology uses the principle of measuring the sound velocity of ultrasonic wave propagation, then measures the average molecular weight of the gas, and then calculates the concentration of the gas to be measured, which has the advantages of small volume, low power consumption, fast response time, and long service life.

[0032] Thermal conductivity sensor:

[0033] The gas concentration is measured according to the difference in the thermal conductivity of different gases at a certain temperature. The application of the thermal conductivity gas sensor in the field of refrigerant leakage detection has the characteristics of small volume, high reliability, and fast response time.

[0034] S2: Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor.

[0035] It can be understood that in the actual process, the influence amounts of the first gas and the second gas on the first sensor and the second sensor can be obtained, and the concentrations of the first gas and the second gas are taken as unknowns, and then equations are listed through the output values of the first sensor and the second sensor, and the concentration value of the first gas and / or the second gas is calculated by solving the equations.

[0036] Preferably, before the first sensor and the second sensor perform actual measurement, they are calibrated, specifically: when the concentration of the first gas changes by a certain value, the first gas value generated by the first sensor only based on the change in the concentration of the first gas is the same as the first gas value generated by the second sensor only based on the change in the concentration of the first gas;

[0037] Take Figure 8For example, the influence of the first gas on the first sensor is as shown in line 1: Y1 = K1X; the influence of the first gas on the second sensor is as shown in line 2: Y2 = K2X; where X is the actual concentration of the first gas, and Y1 and Y2 are the change values generated by the first sensor and the second sensor respectively due to the influence of the first gas. When it is required to make the first gas value generated by the first sensor based only on the change in the first gas concentration and the first gas value generated by the second sensor based only on the change in the first gas concentration the same when the concentration of the first gas changes, there are three ways to achieve this.

[0038] 1. The coefficient of the first sensor can be adjusted. For example, by K1×K3 = K2, the influence of the first gas on the first sensor is changed to: Y1 = K1×K3X. At this time, this function line coincides with the above line 2. 2. The coefficient of the second sensor can be adjusted. For example, by K2×K4 = K1, the influence of the first gas on the second sensor is changed to: Y2 = K2×K4X. At this time, this function line coincides with the above line 1. 3. The coefficients of both the first sensor and the second sensor are adjusted so that both of the adjusted function lines become Y = K5X.

[0039] At this time, when the concentration of the second gas changes, the second gas value generated by the first sensor based only on the change in the second gas concentration is X times the second gas value generated by the second sensor based only on the change in the second gas concentration.

[0040] It should be noted that this X times can be determined based on the response coefficients of the first sensor and the second sensor to the second gas and the values after correction of the first sensor and / or the second sensor in the above steps.

[0041] The above process is essentially the calibration process of the first sensor and the second sensor before measurement in the present invention. After calibration, the following conclusions can be obtained: The response values of the first sensor and the second sensor to the first gas are the same, and the responses of the first sensor and the second sensor to the second gas or interfering gas are in an X - fold relationship.

[0042] In this way, combining steps S1 and S2, we can obtain C1 = C + C2; C3 = C + C4; C2 = X×C4; where C1 is the output value of the first sensor, C is the first gas value of the first sensor and also the first gas value of the second sensor, C2 is the second gas value of the first sensor, C3 is the output value of the second sensor, and C4 is the second gas value of the second sensor. At this time, the unknowns are C, C2, and C4, and the system of equations can be solved by combining them.

[0043] Please refer to Figure 2 , Figure 2 which is the flow schematic diagram of step S2 in the first case of the present invention;

[0044] Step S2 includes the following:

[0045] S21. Determine whether the output values of the first sensor and the second sensor are the same. If so, use the measured value of the sensor with higher measurement accuracy among the first sensor and the second sensor, or the measured value of one of the sensors, as the concentration value of the first gas; otherwise, proceed to step S22;

[0046] Of course, if only the concentration value of the first gas needs to be output here, it can be directly output;

[0047] If the concentration of the second gas is required, at this time, no result can also be output, or the concentration value of the second gas can be output as 0;

[0048] If the concentration of the first gas and the concentration of the second gas need to be output simultaneously, at this time, directly output the concentration of the first gas. For the second gas, the concentration value of the second gas can be output as 0, or the result can be not displayed.

[0049] S22. Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor;

[0050] Or, please refer to Figure 3 , Figure 3 is the flow schematic diagram of step S2 in the second case of the present invention;

[0051] S21. Determine whether the output values of the first sensor and the second sensor are the same. If so, use the measured value of one of the sensors as the concentration value of the first gas; otherwise, proceed to step S22;

[0052] S22. Determine whether the output value of the first sensor is X times the output value of the second sensor. If so, use the measured value of the sensor with higher measurement accuracy among the first sensor and the second sensor, or the measured value of one of the sensors, as the concentration value of the second gas; otherwise, proceed to step S23;

[0053] It should be noted that if only the concentration value of the second gas needs to be output here, it can be directly output;

[0054] If the concentration of the first gas is required, at this time, no result can also be output, or the concentration value of the first gas can be output as 0;

[0055] If the concentration of the first gas and the concentration of the second gas need to be output simultaneously, at this time, directly output the concentration of the second gas. For the first gas, the concentration value of the first gas can be output as 0, or the result can be not displayed.

[0056] S23. Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor;

[0057] Or, please refer to Figure 4 , Figure 4 which is the schematic flow chart of step S2 in the third case of the present invention;

[0058] S21. Determine whether the output value of the first sensor is X times the output value of the second sensor. If so, use the measurement value of the sensor with higher measurement accuracy among the first sensor and the second sensor or the measurement value of one of the sensors as the second gas concentration value; otherwise, go to step S22;

[0059] It should be noted that if only the concentration value of the second gas needs to be output here, it can be directly output;

[0060] If the concentration of the first gas is required, no result can also be output at this time, or the concentration value of the first gas can be output as 0;

[0061] If the concentrations of the first gas and the second gas need to be output simultaneously, the concentration of the second gas is directly output at this time. For the first gas, the concentration value of the first gas can be output as 0, or the result can be not displayed.

[0062] S22. Calculate the concentration value of the first gas and / or the second gas through the output value of the first sensor and the output value of the second sensor;

[0063] Or, please refer to Figure 5 , Figure 5 which is the schematic flow chart of step S2 in the fourth case of the present invention;

[0064] S21. Determine whether the output value of the first sensor is X times the output value of the second sensor. If so, use the measurement value of the sensor with higher measurement accuracy among the first sensor and the second sensor or the measurement value of one of the sensors as the second gas concentration value; otherwise, go to step S22;

[0065] It should be noted that if only the concentration value of the second gas needs to be output here, it can be directly output;

[0066] If the concentration of the first gas is required, no result can also be output at this time, or the concentration value of the first gas can be output as 0;

[0067] If the concentrations of the first gas and the second gas need to be output simultaneously, the concentration of the second gas is directly output at this time. For the first gas, the concentration value of the first gas can be output as 0, or the result can be not displayed;

[0068] S22. Determine whether the output value of the first sensor is the same as the output value of the second sensor. If so, use the measurement value of one of the sensors as the concentration value of the first gas; otherwise, go to step S23;

[0069] Of course, if only the concentration value of the first gas needs to be output here, it can be directly output;

[0070] If the concentration of the second gas is required, no result can also be output at this time, or the concentration value of the second gas can be output as 0;

[0071] If the concentration of the first gas and the concentration of the second gas need to be output simultaneously, the concentration of the first gas is directly output at this time. For the second gas, the concentration value of the second gas can be output as 0, or the result can be not displayed;

[0072] S23. Calculate the concentration value of the first gas and / or the second gas through the output value of the first sensor and the output value of the second sensor.

[0073] The present invention further improves the sensitivity of the sensor. For the convenience of description, it is assumed that the first gas is the target gas (which can also be called the aforementioned gas to be measured), and the second gas is the interfering gas; specifically:

[0074] The first sensor is set such that the influence of the first gas to be detected on the sensor signal value and the influence of the second gas to be detected on the sensor signal value are both positive or negative;

[0075] The second sensor is set such that among the influence of the first gas to be detected on the sensor signal value and the influence of the second gas to be detected on the sensor signal value, one is positive and the other is negative;

[0076] At this time, in step S2, based on the output value of the first sensor and the output value of the second sensor, the target gas value is calculated, or the target gas value and the interfering gas value are calculated.

[0077] It should be noted that the understanding of positive or negative in the influence of the aforementioned gas to be detected on the sensor signal value is as follows:

[0078] Since different types of sensors have different response degrees to different gases as mentioned above. Specifically:

[0079] According to the ultrasonic sensor measurement principle, the greater the difference value between the molecular mass of the test gas mixture and the molecular mass of the background gas, the greater the sensor response degree. For example, the higher the test gas concentration, the higher the molecular mass ratio of the mixture with air to the air molecular mass, and the higher the sensor response degree;

[0080] According to the thermal conductivity sensor measurement principle, the greater the difference value between the thermal conductivity coefficient of the test gas mixture and the thermal conductivity coefficient of the background gas air, the greater the sensor response degree. For example, the higher the test gas concentration, the greater the difference between the thermal conductivity coefficient of the mixture with air and that of pure air, and the higher the sensor response degree;

[0081] For example, when the gas is only air, the gas molecular mass measured using an ultrasonic sensor is 28.8 g / mol. When the gas to be measured is only ethanol, the gas molecular mass measured using an ultrasonic sensor is: 46 g / mol. At this time, it shows that when in the mixed gas of air and ethanol, the higher the ethanol concentration, the closer the value measured by the ultrasonic sensor is to 46 g / mol, which is greater than 28.8 g / mol of pure air. That is to say, it reflects that the higher the ethanol concentration, the larger the value measured by the ultrasonic sensor.

[0082] When the gas is only air, the thermal conductivity coefficient measured using a thermal conductivity sensor is 25.9 mW / (m·K). When the gas to be measured is only ethanol, the gas molecular mass measured using a thermal conductivity sensor is: 15.2 mW / (m·K). At this time, it shows that when in the mixed gas of air and ethanol, the higher the ethanol concentration, the closer the value measured by the thermal conductivity sensor is to 15.2 mW / (m·K), which is less than 25.9 mW / (m·K) of pure air. That is to say, it reflects that the higher the ethanol concentration, the smaller the value measured by the thermal conductivity sensor.

[0083] That is to say, taking the same gas to be measured, ethanol as an example, the response of the ultrasonic sensor to its change is positive, and the response of the thermal conductivity sensor to its change is negative.

[0084] For example, when the gas is only air, the gas molecular mass measured using an ultrasonic sensor is 28.8 g / mol. When the gas to be measured is only water vapor, the gas molecular mass measured using an ultrasonic sensor is: 18 g / mol. At this time, it shows that when in the mixed gas of air and water vapor, the higher the water vapor concentration, the closer the value measured by the ultrasonic sensor is to 18.4 g / mol, which is less than 28.8 g / mol of pure air. That is to say, it reflects that the higher the water vapor concentration, the smaller the value measured by the ultrasonic sensor.

[0085] When the gas is only air, the thermal conductivity coefficient measured using a thermal conductivity sensor is 25.9 mW / (m·K). When the gas to be measured is only water vapor, the gas molecular mass measured using a thermal conductivity sensor is: 18.4 mW / (m·K). At this time, it shows that when in the mixed gas of air and water vapor, the higher the water vapor concentration, the closer the value measured by the thermal conductivity sensor is to 18.4 mW / (m·K), which is less than 25.9 mW / (m·K) of pure air. That is to say, it reflects that the higher the water vapor concentration, the smaller the value measured by the thermal conductivity sensor.

[0086] That is to say, taking the same gas to be measured, water vapor, with the background gas being air as an example, the response of the ultrasonic sensor to its change is reverse, and the response of the thermal conductivity sensor to its change is negative. This is the concept of positive and negative mentioned in the present invention.

[0087] Based on the above concepts, the foregoing "The first sensor is set such that the influence of the first gas to be detected on the sensor signal value and the influence of the second gas to be detected on the sensor signal value are both positive or both negative" can be understood as:

[0088] The ultrasonic sensor's responses to the changes in the first gas to be measured and the second gas to be measured are both positive, or the ultrasonic sensor's responses to the changes in the first gas to be measured and the second gas to be measured are both negative.

[0089] For example, if the first gas to be measured above is water vapor and the ultrasonic sensor's response to its change is negative at this time, then the ultrasonic sensor's response to the change in the second gas to be measured should also be negative. For example, the second gas to be measured is methane; for example, if the first gas to be measured above is ethanol and the ultrasonic sensor's response to its change is positive at this time, then the ultrasonic sensor's response to the change in the second gas should also be positive. For example, the second gas to be measured is CO2.

[0090] Of course, in the above description process, it is default that the ultrasonic sensor is the first sensor and the thermal conductivity sensor is the second sensor. It should be noted that in some other embodiments, the types of the first sensor and the second sensor can also be interchanged. This is only for explanatory purposes and is not intended to be limiting.

[0091] Based on the above concepts, the foregoing "The second sensor is set such that one of the influence of the first gas to be detected on the sensor signal value and the influence of the second gas to be detected on the sensor signal value is positive and the other is negative;" can be understood as,

[0092] If for the first gas to be measured, the thermal conductivity sensor's response to its change is positive, then the thermal conductivity sensor's response to the change in the second gas to be measured is negative, or if for the first gas to be measured, the thermal conductivity sensor's response to its change is negative, then the thermal conductivity sensor's response to the change in the second gas to be measured is positive.

[0093] For example, if the first gas to be measured is water vapor and the thermal conductivity sensor's response to its change is negative, then the thermal conductivity sensor's response to the change in the second gas to be measured should be positive. For example, the second gas to be measured is methane; for example, if the first gas to be measured is methane and the thermal conductivity sensor's response to its change is positive, then the thermal conductivity sensor's response to the change in the second gas to be measured should be negative. For example, the second gas to be measured is water vapor.

[0094] Taking the calculation of the first gas value as an example, as described above:

[0095] C1 = C + C2;

[0096] C3 = C + C4;

[0097] C2 = X × C4;

[0098] Among them, C1 is the output value of the first sensor, C is the first gas value of the first sensor and also the first gas value of the second sensor, C2 is the second gas value of the first sensor, C3 is the output value of the second sensor, and C4 is the second gas value of the second sensor. At this time, the unknown quantities are C, C2, and C4, which can be solved by the simultaneous equations, and C=(C1-C3×X) / (1-X);

[0099] As an embodiment, the first gas is methane and the second gas is water vapor. The first gas is the target gas and the second gas is the interference gas. At this time, the ultrasonic sensor (first sensor) responds negatively to changes in water vapor and methane, that is, the interference gas has the same effect on the ultrasonic sensor as the gas to be measured; the thermal conductivity sensor (second sensor) responds negatively to changes in water vapor and positively to changes in methane, that is, the interference gas has an opposite effect on thermal conductivity compared to the gas to be measured. At this time, the aforementioned K1 is a negative value, and K2 is a positive value. To adjust the coefficient of the second sensor, K4=K1 / K2, K4 is a negative value, and X is related to K4 and the slope of the line of the first sensor and the second sensor that changes with the second gas. Because K4 is a negative value, and the slopes of the lines of the first sensor and the second sensor that change with the second gas are both negative values, X is a negative value. When X is a negative value, in the above formula C=(C1-C3×X) / (1-X), due to the influence of C3, the increase in the numerator is actually smaller than the denominator, so the final C is larger than when X is a positive value, which is reflected in the increase in the response sensitivity of the combined sensor.

[0100] It should be noted that, before step S1, or in step S1, a humidity measurement value is also obtained through a humidity sensor. On this basis, please refer to Figure 6 , Figure 6 This is a schematic diagram of the detection process of the first case after adding the humidity sensor;

[0101] The output value of the first sensor and the output value of the second sensor are combined with the humidity measurement value to remove the humidity influence, and then the concentration value of the first gas and / or the second gas is calculated;

[0102] Or, please refer to Figure 7 , Figure 7 This is a schematic diagram of the detection process of the second case after adding the humidity sensor;

[0103] When calculating the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor, the humidity measurement value is substituted into the calculation as a known constant to remove the influence of humidity.

[0104] In the present invention, a humidity sensor is added to detect humidity, thereby eliminating the influence of humidity on the detection result during the detection process and further improving the detection accuracy.

[0105] It should be noted that Figure 6 in the example shown, obtaining the humidity value using the humidity sensor is before step S1. However, in this example, it can also be that obtaining the humidity value using the humidity sensor is during step S1. Figure 7 in the example shown, obtaining the humidity value using the humidity sensor is during step S1. However, in this example, it can also be that obtaining the humidity value using the humidity sensor is before step S1.

[0106] It should be noted that when there are third to Nth gases to be measured, the multi-sensor combination further includes a third sensor to an Nth sensor, or, the first sensor is a thermal conductivity or MOX sensor;

[0107] When the multi-sensor combination further includes a third sensor to an Nth sensor, the measurement principles of the sensors are different, the output values of the sensors include several of the first gas value to the Nth gas value, and each sensor is configured to have a linear response to any one of the first gas to the Nth gas;

[0108] At this time, step S2 includes calculating the concentrations of several of the first gas value to the Nth gas value based on the output values of the first sensor to the Nth sensor;

[0109] It should be noted that here, the first gas is taken as the target gas and the second to Nth gases are all interference gases for illustration. Of course, in the actual process, the first to Nth gases can all be target gases, or all be interference gases, or several of them can be target gases and several be interference gases, which does not affect the specific calculation process.

[0110] According to the similar calculation method described above, the solution process at this time should be:

[0111] C1 = C0 + Y 11 + Y 12 +…+ Y 1（N-1） ;

[0112] C2 = C0 + Y 21 + Y 22 +…+ Y 2（N-1） ;

[0113] C3 = C0 + Y 31 + Y 32 +…+ Y 3（N-1） ;

[0114] …

[0115] C N=C0 + Y N1 +Y N2 +…+Y N（N-1） ; where C1 - C N are the display values of the first to the Nth sensors; C0 is the value of the target gas, and Y 11 is the response value of the first sensor to the second gas. Similarly, Y 1（N-1） is the response value of the first sensor to the Nth gas; Y 21 is the response value of the second sensor to the second gas. Similarly, Y 2（N-1） is the response value of the second sensor to the Nth gas; Y 31 is the response value of the third sensor to the second gas. Similarly, Y 3（N-1） is the response value of the third sensor to the Nth gas; Y N1 is the response value of the Nth sensor to the second gas. Similarly, Y N（N-1） is the response value of the Nth sensor to the Nth gas;

[0116] It should be noted that, among them, by using the aforementioned calibration, Y 21 to Y N1 can all be expressed by multiplying Y 11 by a certain coefficient. Similarly, Y 22 to Y N2 can all be expressed by multiplying Y 12 by a certain coefficient,..., Y 2(N-1) to Y N（N-1） can all be expressed by multiplying Y 1(N-1) by a certain coefficient;

[0117] The above accumulates to a total of N equations to solve for a total of N unknowns including C0, Y 11 , Y 12 ... Y 1（N-1） .

[0118] When the first sensor is a thermal conductivity or MOX sensor, the first sensor outputs N - 1 output values at at least N - 1 temperatures;

[0119] At this time, the step S2 includes calculating the concentrations of several of the first gas value to the Nth gas value based on the N - 1 output values of the first sensor and the output value of the second sensor.

[0120] Specifically, the mixed gas is composed of the first gas to the Nth gas. At this time, the first sensor outputs different values at different set temperatures. For example, at the first set temperature t 1, the output value of the first sensor is C 1, which means that C 1 includes all or several of the first gas to the Nth gas, and can be denoted as:

[0121] C1 = C0 + Y 11 + Y 12 + … + Y 1（N-1） ;

[0122] Where C0 is the response value of the first sensor to the first gas; Y 11 is the response value of the first sensor to the second gas at the first set temperature t1; Y 1（N-1） is the response value of the first sensor to the Nth gas; correspondingly, at different set temperatures N - 1, there is:

[0123] C N-1 = C0 + Y (N-1)1 + Y (N-1)2 + … + Y (N-1)（N-1）

[0124] Plus the output value C of the second sensor N = C0 + Y N1 + Y N2 + … + Y N（N-1） , a total of N equations, and Y 21 to Y N1 can all be expressed by multiplying Y 11 by a certain coefficient. Similarly, Y 22 to Y N2 can all be expressed by multiplying Y 12 by a certain coefficient, …, Y 2(N-1) to Y N（N-1） can all be expressed by multiplying Y 1(N-1) by a certain coefficient. By solving the equations simultaneously, the concentrations of the first gas to the Nth gas or several of them can be obtained.

[0125] It should be noted that the first gas is the target gas, and at least two of the second to Nth gases are interfering gases;

[0126] When the multi - sensor combination further includes the third sensor to the Nth sensor, the first sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interference on the sensor signal value are both positive or negative, and at least two of the second to Nth sensors are set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are one positive and the other negative;

[0127] It should be noted that the essence of the process of improving the sensitivity above is the same as the corresponding situation described above, with the only difference being that there is one or several more test gases or interfering gases.

[0128] Alternatively, when the multi-sensor combination further includes a third sensor to an Nth sensor, the first sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interference on the sensor signal value are one positive and the other negative, and at least two of the second to Nth sensors are set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are both positive or both negative; or, when the first sensor is a thermal conductivity or MOX sensor, the first sensor is set at at least two temperatures such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are both positive or both negative; the second sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are one positive and the other negative; or, when the first sensor is a thermal conductivity or MOX sensor, the first sensor is set at at least two temperatures such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are one positive and the other negative; the second sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are both positive or both negative; at this time, the target gas value is calculated based on the output value of the first sensor and the output value of the second sensor, or several of the target gas value and the interfering gas are calculated. In this way, the sensitivity during the measurement of the target gas can also be improved.

[0129] The device of the present invention includes: a first sensor, a second sensor, and a controller; the first sensor and the second sensor are configured to output values, and each output value includes a first gas value and / or a second gas value; the first sensor and the second sensor are both configured to have a linear response to any one of the first gas and the second gas; the first sensor and the second sensor are configured as sensors with different detection principles; the controller executes the steps of the above-mentioned gas detection method based on the multi-sensor combination.

[0130] As another embodiment, please refer to Figure 9 , Figure 9 is a schematic diagram of the device of the present invention.

[0131] A gas detection device based on a multi-sensor combination includes: an upper cover 2-1 with an air intake grille, a lower cover 2-10. A snap design is adopted between the upper cover 2-1 and the lower cover 2-10. Between the upper cover 2-1 and the lower cover 2-10, there are provided a multi-sensor combination, a humidity sensor ( Figure 9 not shown in the figure), a PCB board 2-8. Among them, the multi-sensor combination and the humidity sensor are soldered on the PCB board 2-8 and are connected to the controller on the PCB board ( Figure 9... are electrically connected (not visible in the figure); on the PCB board, a first shielding cover 2-3 and a waterproof and breathable membrane 2-2 are sequentially arranged from bottom to top; a second shielding cover 2-9 is also arranged between the PCB board 2-8 and the lower cover 2-10;

[0132] Wherein the controller includes a processor and a storage medium; the processor loads and executes the instructions and data in the storage medium to implement the described gas detection method based on multi-sensor combination.

[0133] It should be noted that the multi-sensor combination is: a group of ultrasonic detectors 2-4 and a thermal conductivity sensor chip 2-7; two groups of ultrasonic detector chambers are also arranged beside the ultrasonic detectors 2-4, namely the first ultrasonic sensor chamber 2-5 and the second ultrasonic sensor chamber 2-6.

[0134] The working principle of the device is as follows:

[0135] The test gas passes through the upper cover 2-1 and enters the integrated sensor chamber through the waterproof and breathable membrane 2-2. There are the second ultrasonic sensor chamber 2-6 and the thermal conductivity sensor chip 2-7 in the chamber. The ultrasonic and thermal conductivity sensors will measure the concentration of the entering gas. The controller compares and judges the influence of environmental interference gases on the measurement signals of the ultrasonic and thermal conductivity sensors to improve the reliability of the measurement results; at the same time, the temperature and humidity chip in the integrated sensor chamber measures the environmental temperature and humidity. The temperature and humidity measurement results will correct the ultrasonic and thermal conductivity measurement results to improve the accuracy of the sensor output results. When the concentration of the test gas exceeds the alarm value, an alarm signal is output. In addition, the first shielding cover 2-3 and the second shielding cover 2-9 can effectively shield external electromagnetic interference and improve the anti-interference ability of the sensors.

[0136] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A gas detection method based on multi-sensor combination, characterized in that: The method includes the following steps: S1: Construct a multi-sensor combination and obtain its output value; The multi-sensor combination includes: a first sensor and a second sensor; Wherein, the output values of the first sensor and the second sensor both include a first gas value and a second gas value; both the first sensor and the second sensor are configured to have a linear response to any one of the first gas and the second gas; the first sensor and the second sensor are configured as sensors with different detection principles; S2: Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor; Specifically: Obtain the influence amounts of the first gas and the second gas on the first sensor and the second sensor, and take the concentrations of the first gas and the second gas as unknowns respectively, then list equations through the output values of the first sensor and the second sensor, and calculate the concentration value of the first gas and / or the second gas by solving the equations.

2. The gas detection method based on multi-sensor combination according to claim 1, characterized in that: Before the first sensor and the second sensor perform actual measurement, they are calibrated. Specifically: When the concentration of the first gas changes by a certain value, the first gas value generated by the first sensor only based on the change in the concentration of the first gas is the same as the first gas value generated by the second sensor only based on the change in the concentration of the first gas; At this time, when the concentration of the second gas changes by a certain value, the second gas value generated by the first sensor only based on the change in the concentration of the second gas is X times the second gas value generated by the second sensor only based on the change in the concentration of the second gas.

3. The gas detection method based on multi-sensor combination according to claim 2, characterized in that: Step S2 includes the following: S21. Judge whether the output value of the first sensor is the same as the output value of the second sensor. If so, use the measurement value of the sensor with higher measurement accuracy among the first sensor and the second sensor or the measurement value of one of the sensors as the concentration value of the first gas; otherwise, go to step S22; S22. Calculate the concentration value of the first gas and / or the second gas through the output value of the first sensor and the output value of the second sensor; Or, S21. Judge whether the output value of the first sensor is the same as the output value of the second sensor. If so, use the measurement value of one of the sensors as the concentration value of the first gas; otherwise, go to step S22; S22. Judge whether the output value of the first sensor is X times the output value of the second sensor. If so, use the measurement value of the sensor with higher measurement accuracy among the first sensor and the second sensor or the measurement value of one of the sensors as the concentration value of the second gas; Otherwise, go to step S23; S23. Calculate the concentration value of the first gas and / or the second gas through the output value of the first sensor and the output value of the second sensor; Or, S21. Judge whether the output value of the first sensor is B times the output value of the second sensor. If so, use the measurement value of the sensor with higher measurement accuracy among the first sensor and the second sensor or the measurement value of one of the sensors as the concentration value of the second gas; otherwise, go to step S22; S22. Calculate the concentration value of the first gas and / or the second gas through the output value of the first sensor and the output value of the second sensor; Or, S21. Determine whether the output value of the first sensor is X times the output value of the second sensor. If so, use the measurement value of the sensor with higher measurement accuracy among the first sensor and the second sensor, or the measurement value of one of the sensors as the second gas concentration value; otherwise, proceed to step S22; S22. Determine whether the output values of the first sensor and the second sensor are the same. If so, use the measurement value of one of the sensors as the concentration value of the first gas; otherwise, proceed to step S23; S23. Calculate the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor.

4. A gas detection method based on multi-sensor combination according to claim 1 or 2, characterized in that: The first gas is the target gas, and the second gas is the interfering gas; The first sensor is set such that the influence of the first gas to be detected on the sensor signal value and the influence of the second gas to be detected on the sensor signal value are both positive or both negative; The second sensor is set such that the influence of the first gas to be detected on the sensor signal value and the influence of the second gas to be detected on the sensor signal value are one positive and the other negative; At this time, in step S2, calculate the target gas value based on the output value of the first sensor and the output value of the second sensor, or calculate the target gas value and the interfering gas value.

5. The gas detection method based on multi-sensor combination according to claim 1, characterized in that: Before step S1, or in step S1, also obtain the humidity measurement value through a humidity sensor.

6. The gas detection method based on multi-sensor combination according to claim 5, wherein: Step S2 specifically includes: Combine the output value of the first sensor and the output value of the second sensor with the humidity measurement value to remove the humidity influence, and then calculate the concentration value of the first gas and / or the second gas; or, when calculating the concentration value of the first gas and / or the second gas based on the output value of the first sensor and the output value of the second sensor, use the humidity measurement value as a known constant and substitute it into the calculation to remove the humidity influence.

7. The gas detection method based on multi-sensor combination according to claim 1, characterized in that: When there are third to Nth gases to be measured, the multi-sensor combination further includes a third sensor to an Nth sensor, or the first sensor is a thermal conductivity or MOX sensor; When the multi-sensor combination further includes a third sensor to an Nth sensor, the measurement principles of each sensor are different, the output value of each sensor includes several of the first gas value to the Nth gas value, and each sensor is configured to have a linear response to any one of the first gas to the Nth gas; At this time, step S2 includes calculating the concentration of several of the first gas value to the Nth gas value based on the output values of the first sensor to the Nth sensor; When the first sensor is a thermal conductivity or MOX sensor, the first sensor outputs N - 1 output values at at least N - 1 temperatures; At this time, step S2 includes calculating the concentration of several of the first gas value to the Nth gas value based on the N - 1 output values of the first sensor and the output value of the second sensor.

8. The gas detection method based on multi-sensor combination according to claim 7, characterized in that: The first gas is the target gas, and at least two of the second to Nth gases are interfering gases; When the multi-sensor combination further includes a third sensor to an Nth sensor, the first sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interference on the sensor signal value are both positive or both negative, and at least two of the second to Nth sensors are set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are one positive and the other negative; Alternatively, when the multi-sensor combination further includes a third sensor to an Nth sensor, the first sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interference on the sensor signal value are one positive and the other negative, and at least two of the second to Nth sensors are set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are both positive or both negative; Alternatively, when the first sensor is a thermal conductivity or MOX sensor, the first sensor is set at at least two temperatures such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are both positive or both negative; the second sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are one positive and the other negative; Alternatively, when the first sensor is a thermal conductivity or MOX sensor, the first sensor is set at at least two temperatures such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are one positive and the other negative; the second sensor is set such that the influence of the target gas on the sensor signal value and the influence of the interfering gas on the sensor signal value are both positive or both negative; At this time, based on the output value of the first sensor and the output value of the second sensor, the target gas value is calculated, or several of the target gas value and the interfering gas are calculated.

9. The gas detection method based on multi-sensor combination according to claim 1, wherein: The first sensor is a thermal conductivity sensor and the second sensor is an ultrasonic sensor.

10. A gas detection device based on multi-sensor combination, characterized in that, Comprising: A first sensor, a second sensor, and a controller; the first sensor and the second sensor are configured to output values, and each output value includes a first gas value and / or a second gas value; both the first sensor and the second sensor are configured to have a linear response to any one of the first gas and the second gas; the first sensor and the second sensor are configured to be sensors with different detection principles; the controller executes the steps of the gas detection method based on a multi-sensor combination according to any one of claims 1-9.

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