CN114324501A - Dynamic compensation method for humidity sensor - Google Patents
Dynamic compensation method for humidity sensor Download PDFInfo
- Publication number
- CN114324501A CN114324501A CN202111622564.5A CN202111622564A CN114324501A CN 114324501 A CN114324501 A CN 114324501A CN 202111622564 A CN202111622564 A CN 202111622564A CN 114324501 A CN114324501 A CN 114324501A
- Authority
- CN
- China
- Prior art keywords
- humidity
- temperature
- sensor
- humidity sensor
- water molecules
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000000034 method Methods 0.000 title claims abstract description 54
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 57
- 238000009792 diffusion process Methods 0.000 claims abstract description 38
- 238000012546 transfer Methods 0.000 claims abstract description 36
- 238000012360 testing method Methods 0.000 claims abstract description 25
- 238000005259 measurement Methods 0.000 claims abstract description 23
- 230000004044 response Effects 0.000 claims abstract description 20
- 239000000523 sample Substances 0.000 claims abstract description 19
- 230000008569 process Effects 0.000 claims abstract description 17
- 238000005070 sampling Methods 0.000 claims description 27
- 230000008859 change Effects 0.000 claims description 21
- 239000011159 matrix material Substances 0.000 claims description 16
- 230000007704 transition Effects 0.000 claims description 15
- 229920006395 saturated elastomer Polymers 0.000 claims description 6
- 238000013139 quantization Methods 0.000 claims description 5
- 239000011541 reaction mixture Substances 0.000 claims description 5
- 238000013528 artificial neural network Methods 0.000 claims description 3
- 239000002245 particle Substances 0.000 claims description 3
- 238000000926 separation method Methods 0.000 claims description 3
- 238000006467 substitution reaction Methods 0.000 claims description 3
- 230000001419 dependent effect Effects 0.000 claims description 2
- 239000004642 Polyimide Substances 0.000 description 12
- 229920001721 polyimide Polymers 0.000 description 12
- 230000001052 transient effect Effects 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
Images
Landscapes
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
A dynamic compensation method for humidity sensor is disclosed, which includes introducing the average concentration of water molecules in air u (k) and the average concentration of water molecules in humidity probe y (k) as identification objects, and testing the humidity step response of humidity sensor at constant temperature to determine the system transfer function G (Z) and the system state space model sigma0(ii) a The influence of temperature variable on the humidity of the probe is equivalent to the influence of measurement interval on the humidity under constant temperature through analyzing the water molecule diffusion equation in the humidity sensor, and a system state space model sigma is utilized0And measuring the temperature TkQuantifying to determine the system transfer function G with temperatureK(Z) obtaining a compensated humidity measurement value RHC (k). The compensation process in the method only needs to carry out humidity step response test on the sensor under the constant temperature condition, thereby reducing the test difficulty and simultaneously ensuring the accuracy of the compensation model when the temperature changes.
Description
Technical Field
The disclosure relates to the technical field of sensor compensation, in particular to a dynamic compensation method of a humidity sensor.
Background
The polyimide capacitive humidity sensor is a widely applied humidity sensor, and the main working principle of the polyimide capacitive humidity sensor is that moisture molecules in air are absorbed by a moisture-sensitive capacitance medium, and the dielectric constant of a sensitive capacitor changes, so that the capacitance value is changed. In the MEMS process flow for processing the polyimide capacitive humidity sensor, a humidity sensing medium such as polyimide is coated between comb-tooth-shaped electrodes, after moisture absorption of the humidity sensing medium between the electrodes, the dielectric constant changes, the capacitance value between the electrodes also changes, and the capacitance change is converted into a digital signal to be output through the steps of capacitance voltage conversion, ADC and the like. Polyimide capacitive humidity sensors have a series of advantages such as high sensitivity, low power consumption and small temperature deviation, and thus are the mainstream solutions for widely applied miniaturized humidity sensors. However, the polyimide capacitive humidity sensor has the problems of long response time, poor dynamic characteristics, measurement distortion for transient change and the like.
Meanwhile, the polyimide capacitive humidity sensor is greatly influenced by temperature in the humidity measuring process. The traditional single variable sensor compensation method is suitable for a linear steady system, the polyimide capacitance type humidity sensor is greatly influenced by temperature, and when the temperature changes to a certain degree in the humidity measuring process, the result obtained by the traditional dynamic compensation method can generate large deviation. If the sensor system is regarded as a temperature and humidity binary input system to carry out system identification, the output of the sensor system when the temperature and the humidity change simultaneously is required to be tested, the control of the dynamic temperature and humidity environment has higher precision requirement, and the testing difficulty is greatly increased.
Disclosure of Invention
In view of the above, the present disclosure provides a dynamic compensation method for a humidity sensor to solve at least one of the above and other technical problems.
In order to achieve the above object, the present disclosure provides a dynamic compensation method of a humidity sensor, including: s1: selecting the average concentration u (k) of water molecules in the outside air and the average concentration y (k) of water molecules in a humidity probe of a humidity sensor as an identification object to obtain a functional relation of the identification object relative to humidity and temperature; s2: carrying out humidity step response test on the humidity sensor under the constant temperature condition; s3: determining a system transfer function G (Z) of the humidity sensor through an algorithm according to a humidity step response test result; s4: converting the transfer function G (Z) of the sensor system into a state space model sigma of the sensor system0(ii) a S5: according to the diffusion equation, the influence of the temperature variable on the diffusion of water molecules or the humidity is equivalent to the time when the water molecules in the measurement interval are diffused under constant temperatureInfluence of intervarietal change on water molecule diffusion or humidity converts a state space model of the sensor system into a homogeneous equation form; s6: sensor system state space model sigma according to homogeneous equation form0With the measured temperature TkDetermining humidity sensor system transfer function G as a function of temperature using state transition matrix quantizationK(Z); s7: the compensated humidity measurement rhe (k) is calculated.
According to the embodiment of the disclosure, the average concentration u (k) of water molecules in the air outside the identification object and the average concentration y (k) of water molecules in the humidity probe of the humidity sensor can be respectively expressed as:
in the formula (1), ρv(T) is the saturated steam density at the corresponding ambient temperature, MvRHI is the ambient humidity input humidity, and Rho is the sensor output humidity.
According to the embodiment of the disclosure, the algorithm applied by the humidity step response test result comprises any one of a least square method, a particle swarm and a neural network.
According to an embodiment of the present disclosure, the system transfer function g (z) of the humidity sensor is:
where n is the sensor model order, Z is the delay factor, and a and b are the model parameters of the system transfer function.
According to an embodiment of the disclosure, the system transfer function G (Z) corresponds to a state space model ∑0The selected can be observed standard type,
wherein, the corresponding observable standard state space model is as follows:
in formula (3):
C＝[0 0 … 1]
according to an embodiment of the present disclosure, the diffusion equation of water molecules in the sensor probe is:
in the formula (4), De(t) is the water molecule diffusivity;
De(t) is the diffusivity of water molecules as a function of temperature, as:
in the formula (5), the reaction mixture is,
is T0Temperature diffusivity of water molecules.
According to an embodiment of the present disclosure, the diffusion equation is separated by a variable, let N be Nt(t)·Nr(x, y, z) in place of the equation of formula (4):
the separation variable is
Irrespective of NrFor NtIs provided with
Since the measurement of the temperature is also discrete, neglecting the temperature variation in the measurement interval, assume the temperature to be
T(t)＝T(k)kτ≤t＜(k+1)τ (8)
Wherein tau is sampling interval time, separately looking at the time of k tau ≦ t < (k +1) tau, and converting the equivalent time t*＝t·(T/T0)1.75Substitution into equation (7) can yield:
its form and temperature is T0Constant is the same.
According to the embodiment of the disclosure, the diffusion process of the next sampling interval at different temperatures is replaced by the diffusion process at the standard reference temperature for different times, and the replacement relationship is as follows:
τ*＝τ·(T/T0)1.75 (10)
the temperature sampling is discrete, and can be considered as constant temperature in the sampling interval, the temperature in k and k +1 sampling intervals is T (k), and the external environment humidity is not changed into u (k).
According to the embodiment of the disclosure, a state space model of a sensor system is transformed into a homogeneous equation form in a sampling interval, quantization is carried out by utilizing a state transition matrix, and a humidity sensor system transfer function G changing along with temperature is determinedK(Z) a process comprising:
the state space model of the sensor system is transformed into a homogeneous process to introduce a state transition matrix coefficient phi,
in the formula (11), the reaction mixture is,
the above equation is the temperature T at which the time interval is the sampling interval τ and the temperature is constant to identify the sensor system0The state transition matrix in the case of (1), temperature difference and T0Time may be equivalent to a change in the sampling interval. While the temperature and input concentration remain unchanged only the sampling interval becomes τ*＝τ·(T(k)/T0)1.75The system state is changed to:
τ*/τ＝(T(k)/T0)1.75 (14)
setting a sensor state space model which changes along with temperature to be sigmaK：
Then there is
The state space model of the sensor which changes along with the temperature is determined to be sigma through the formulaKThe parameter (c) of (c).
Humidity sensor system transfer function G as a function of temperature, according to embodiments of the present disclosureK(Z) by eliminating the state variable x (k), y (k) and u (k) are obtained as a function of the temperatureThe transfer function of (c):
thus, the relative humidities rho (k) and t (k) output by the humidity sensors obtain the compensation value rhc (k) of the ambient humidity of the air:
according to the dynamic compensation method of the humidity sensor of the embodiment of the disclosure, the humidity sensor system is identified by introducing the average concentration u (k) of water molecules in the air and the average concentration y (k) of water molecules in the humidity probe of the sensor as identification objects; and the influence of temperature variable on the humidity of the probe is equivalent to the influence of the diffusion time change of water molecules in a measurement interval under constant temperature on the humidity by analyzing the water molecule diffusion equation in the humidity sensor, and the system transfer function G changing along with the temperature is determined by quantifying by utilizing a state transfer matrixK(Z), finally obtaining a compensated humidity measured value RHC (k). The compensation process in the method only needs to carry out humidity step response test on the sensor under the constant temperature condition, thereby reducing the test difficulty and simultaneously ensuring the accuracy of the compensation model when the temperature changes.
Drawings
FIG. 1 is a flow chart of a method of dynamic compensation of a humidity sensor of an embodiment of the present disclosure; and
FIG. 2 is a graphical representation of saturated vapor density as a function of temperature.
Detailed Description
For the purpose of promoting a better understanding of the objects, aspects and advantages of the present disclosure, reference is made to the following detailed description taken in conjunction with the accompanying drawings.
The polyimide capacitive humidity sensor has the problems of long response time, poor dynamic characteristics, measurement distortion of transient change and the like. Meanwhile, the polyimide capacitive humidity sensor is greatly influenced by temperature in the humidity measuring process. The traditional single variable sensor compensation method is suitable for a linear steady system, the polyimide capacitance type humidity sensor is greatly influenced by temperature, and when the temperature changes to a certain degree in the humidity measuring process, the result obtained by the traditional dynamic compensation method can generate large deviation. If the sensor system is regarded as a temperature and humidity binary input system to carry out system identification, the output of the sensor system when the temperature and the humidity change simultaneously is required to be tested, the control of the dynamic temperature and humidity environment has higher precision requirement, and the testing difficulty is greatly increased.
To this end, there is provided according to the present disclosure a method of dynamic compensation of a humidity sensor, comprising: s1: selecting the average concentration u (k) of water molecules in the outside air and the average concentration y (k) of water molecules in a humidity probe of a humidity sensor as an identification object to obtain a functional relation of the identification object relative to humidity and temperature; s2: carrying out humidity step response test on the humidity sensor under the constant temperature condition; s3: determining a system transfer function G (Z) of the humidity sensor through an algorithm according to a humidity step response test result; s4: converting the transfer function G (Z) of the sensor system into a state space model sigma of the sensor system0(ii) a S5: according to a diffusion equation, the influence of temperature variables on the diffusion or humidity of water molecules is equivalent to the influence of the diffusion time change of the water molecules in a measurement interval at constant temperature on the diffusion or humidity of the water molecules, and a state space model of the sensor system is converted into a homogeneous equation form; s6: sensor system state space model sigma according to homogeneous equation form0With the measured temperature TkDetermining humidity sensor system transfer function G as a function of temperature using state transition matrix quantizationK(Z); s7: the post-compensation humidity measurement rhc (k) is calculated.
In the dynamic compensation method of the humidity sensor, the humidity sensor system is identified by introducing the average concentration u (k) of water molecules in the air and the average concentration y (k) of water molecules in a humidity probe of the sensor as identification objects, and the influence of temperature variables on the humidity of the probe is equivalent to constant temperature through analyzing the diffusion equation of the water molecules in the humidity sensorThe influence of the diffusion time change of water molecules in the lower measurement interval on the humidity is quantified by using a state transition matrix, and the system transfer function G changing along with the temperature is determinedK(Z), finally obtaining a compensated humidity measured value RHC (k). The compensation process in the method only needs to carry out humidity step response test on the sensor under the constant temperature condition, thereby reducing the test difficulty and simultaneously ensuring the accuracy of the compensation model when the temperature changes.
The technical solution of the present disclosure will be described in detail below with reference to specific examples. It should be noted that the following specific examples are only for illustration and are not intended to limit the disclosure.
FIG. 1 is a flow chart of a method of dynamic compensation of a humidity sensor of an embodiment of the present disclosure.
As shown in fig. 1, the dynamic compensation method of the humidity sensor includes: s1: selecting the average concentration u (k) of water molecules in the outside air and the average concentration y (k) of water molecules in a humidity probe of a humidity sensor as an identification object to obtain a functional relation of the identification object relative to humidity and temperature; s2: carrying out humidity step response test on the humidity sensor under the constant temperature condition; s3: determining a system transfer function G (Z) of the humidity sensor through an algorithm according to a humidity step response test result; s4: converting the transfer function G (Z) of the sensor system into a state space model sigma of the sensor system0(ii) a S5: according to a diffusion equation, the influence of temperature variables on the diffusion or humidity of water molecules is equivalent to the influence of the diffusion time change of the water molecules in a measurement interval at constant temperature on the diffusion or humidity of the water molecules, and a state space model of the sensor system is converted into a homogeneous equation form; s6: sensor system state space model sigma according to homogeneous equation form0With the measured temperature TkDetermining humidity sensor system transfer function G as a function of temperature using state transition matrix quantizationK(Z); s7: the compensated humidity measurement rhe (k) is calculated. The method has the advantages that the compensation process only needs to carry out humidity step response test on the sensor under the constant temperature condition, the test difficulty is reduced compared with the identification compensation method taking temperature and humidity as a binary input system, and the compensation can be ensured when the temperature changesAnd (4) the accuracy of the model.
According to the embodiment of the disclosure, the capacitance change of the probe of the polyimide capacitance type humidity sensor and the humidity output by the sensor directly change along with the temperature, so that the temperature and the humidity directly serve as the identification variables, the temperature and the humidity need to be identified, and the identification difficulty is greatly improved. Therefore, the identification objects of the present disclosure are selected as the average concentration u (k) of water molecules in the outside air and the average concentration y (k) of water molecules in the humidity probe of the humidity sensor, which can be respectively expressed as:
in the formula (1), ρv(T) is the saturated steam density at the corresponding ambient temperature, MvRHI is the ambient humidity input humidity, and Rho is the sensor output humidity.
FIG. 2 is a graphical representation of saturated vapor density as a function of temperature.
According to an embodiment of the present disclosure, ρ in the above formula (1)v(T) is the saturated vapour density at the corresponding ambient temperature, through rhov(T) relating the two identifying variables u (k) and y (k) of equation (1) as a function of temperature, pvThe functional relationship of (T) with temperature is shown in FIG. 2.
According to the embodiment of the disclosure, the algorithm applied by the humidity step response test result comprises any one of a least square method, a particle swarm and a neural network.
According to the embodiment of the disclosure, the system transfer function g (z) of the humidity sensor obtained according to the operation of the humidity step response test result is:
where n is the sensor model order, Z is the delay factor, and a and b are the model parameters of the system transfer function.
According to an embodiment of the present disclosure, the system transfer function G (Z) is inCorresponding state space model ∑0The selected can be observed standard type.
Therefore, the corresponding observable standard state space model is as follows:
in formula (3):
C＝[0 0 ... 1]
according to an embodiment of the present disclosure, the diffusion equation of water molecules in the sensor probe is:
in the formula (4), De(t) is the water molecule diffusivity. The only temperature-dependent property in the formula (4) is the diffusion rate D of water molecules as a function of temperaturee(t) as a function of temperature:
in the formula (5), the reaction mixture is,
the diffusivity of a water molecule is at the temperature T0.
According to an embodiment of the present disclosure, the diffusion equation is separated by a variable, let N be Nt(t)·Nr(x, y, z) in place of the equation of formula (4):
the separation variable is
Irrespective of NrFor NtThen there are:
since the measurement of the temperature is discrete, ignoring temperature variations in the measurement interval, assume that the temperature is:
T(t)＝T(k)kτ≤t＜(k+1)τ (8)
in equation (8), τ is the sampling interval time. When looking at times k τ t < (k +1) τ alone, the equivalent time t will be*＝t·(T/T0)1.75Substitution into equation (7) can yield:
the form and temperature of the formula (9) is T0The equation (7) is the same when the time is constant. From this analysis it can be concluded that an elevated temperature corresponds to an accelerated diffusion process for the movement of water molecules, so that the diffusion of water molecules or the change in humidity caused by a temperature difference during the humidity measurement process can be converted into a change in diffusion of water molecules or humidity caused by a change in diffusion time during the measurement interval.
According to the embodiment of the disclosure, the diffusion process of the next sampling interval at different temperatures is replaced by the process of diffusing at different times at the standard reference temperature, and the replacement relationship is as follows:
τ*＝τ·(T/T0)1.75 (10)
the temperature sampling is discrete, and can be considered as constant temperature in the sampling interval, the temperature in k and k +1 sampling intervals is T (k), and the external environment humidity is not changed into u (k).
According to an embodiment of the present disclosure, a sensor system state space model may be transformed into a homogeneous equation form within one sampling interval:
after the state transition, u (k) still represents the constant concentration of input water molecules in an interval, phi is a state transition matrix coefficient and can be represented by a state space model sigma0Obtaining:
equation (11) is the temperature T at a time interval of the sampling interval τ and at a constant temperature of the identification sensor system0The state transition matrix in the case where the temperature is different from T0The temperature change in time may be equivalent to a change in the sampling interval. When the temperature and input concentration remain unchanged, only the sampling interval becomes τ*＝τ·(T(k)/T0)1.75The system state transition matrix becomes:
τ*/τ＝(T(k)/T0)1.75 (14)
setting a sensor state space model which changes along with temperature to be sigmaK：
Then there is
The state space model of the sensor which changes along with the temperature is determined to be sigma through the formula (15)KThe parameter (c) of (c). However, equation (15) also introduces the state variable x (k):
to eliminate the above variables, the following equations are connected:
x(k+1)＝A(k)·x(k)+B(k)·u(k)
y(k)＝C·x(k)+b0·u(k)
x(k+n)＝A(k+n-1)·x(k+n-1)+B(k+n-1)·u(k+n-1)
y(k+n-1)＝C·x(k+n-1)+b0·u(k+n-1)
y(k+n)＝C·x(k+n)+b0·u(k+n)
eliminating common n in variable process2+ n +1 equations, n2+ n state variables x (k) x (k + n), and the state variable x (k) may be eliminated.
Humidity sensor system transfer function G as a function of temperature, according to embodiments of the present disclosureK(Z) by eliminating the state variable x (k), obtaining a transfer function of y (k) and u (k) as a function of temperature:
according to the embodiment of the present disclosure, the compensation value rhc (k) of the humidity of the air environment is obtained through the relative humidities rho (k) and t (k) output by the humidity sensors:
according to the dynamic compensation method of the humidity sensor of the embodiment of the disclosure, the humidity sensor system is identified by introducing the average concentration u (k) of water molecules in the air and the average concentration y (k) of water molecules in the humidity probe of the sensor as identification objects, the influence of temperature variables on the humidity of the probe is equivalent to the influence of diffusion time change of the water molecules in a measurement interval at constant temperature on the humidity through analyzing the diffusion equation of the water molecules in the humidity sensor, and the system transfer function G changing along with the temperature is determined by quantifying by using a state transfer matrixK(Z), finally obtaining a compensated humidity measured value RHC (k). The compensation process in the method only needs to carry out humidity step response test on the sensor under the constant temperature condition, so that the test difficulty is reduced, and meanwhile, the accuracy of the compensation model can be ensured when the temperature changes.
It should also be noted that directional terms, such as "upper", "lower", "front", "rear", "left", "right", and the like, used in the embodiments are only directions referring to the drawings, and are not intended to limit the scope of the present disclosure. Throughout the drawings, like elements are represented by like or similar reference numerals. Conventional structures or constructions will be omitted when they may obscure the understanding of the present disclosure.
And the shapes and sizes of the respective components in the drawings do not reflect actual sizes and proportions, but merely illustrate the contents of the embodiments of the present disclosure. Furthermore, the word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.
Similarly, it should be appreciated that in the foregoing description of exemplary embodiments of the disclosure, various features of the disclosure are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, the method of the invention should not be construed to reflect the intent: that is, the claimed disclosure requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing inventive embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this disclosure.
The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present disclosure in further detail, and it should be understood that the above-mentioned embodiments are only illustrative of the present disclosure and are not intended to limit the present disclosure, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present disclosure should be included in the scope of the present disclosure.
Claims (10)
1. A method of dynamic compensation of a humidity sensor, comprising:
s1: selecting the average concentration u (k) of water molecules in the outside air and the average concentration y (k) of water molecules in a humidity probe of a humidity sensor as an identification object to obtain a functional relation of the identification object relative to humidity and temperature;
s2: carrying out humidity step response test on the humidity sensor under the constant temperature condition;
s3: determining a system transfer function G (Z) of the humidity sensor through an algorithm according to a humidity step response test result;
s4: converting a sensor system transfer function G (Z) into a sensor system state space model ∑0；
S5: according to a diffusion equation, the influence of temperature variables on the diffusion or humidity of water molecules is equivalent to the influence of the diffusion time change of the water molecules in a measurement interval at constant temperature on the diffusion or humidity of the water molecules, and a state space model of the sensor system is converted into a homogeneous equation form;
s6: sensor system state space model sigma according to homogeneous equation form0With the measured temperature TkDetermining humidity sensor system transfer function G as a function of temperature using state transition matrix quantizationK(Z)；
S7: the post-compensation humidity measurement rhc (k) is calculated.
2. The method for dynamically compensating humidity sensor according to claim 1, wherein the average concentration u (k) of water molecules in the air outside the identification object and the average concentration y (k) of water molecules in the humidity probe of the humidity sensor are respectively represented as:
in the formula (1), ρv(T) is the saturated steam density at the corresponding ambient temperature, MvRHI is the ambient humidity input humidity, and Rho is the sensor output humidity.
3. The method for dynamically compensating the humidity sensor according to claim 1, wherein the algorithm applied by the humidity step response test result comprises any one of a least square method, a particle swarm, and a neural network.
4. The method for dynamic compensation of a humidity sensor according to claim 1, wherein the system transfer function G (Z) of the humidity sensor is:
where n is the sensor model order, Z is the delay factor, and a and b are the model parameters of the system transfer function.
5. The method for dynamic compensation of a humidity sensor according to claim 4,
the system transfer function G (Z) is corresponding to a state space model ∑0The selected can be observed standard type,
wherein, the corresponding observable standard state space model is as follows:
in formula (3):
C＝[0 0…1] 。
6. the method for dynamically compensating for humidity sensor according to claim 1, wherein the diffusion equation of water molecules in the sensor probe is:
in the formula (4), De(t) is the water molecule diffusivity;
De(t) is the diffusivity of water molecules as a function of temperature, as:
in the formula (5), the reaction mixture is,
is T0Temperature diffusivity of water molecules.
7. The method for dynamically compensating for humidity sensor according to claim 1, wherein the diffusion equation is separated by a variable, where N is Nt(t)·Nr(x, y, z) in place of the equation of formula (4):
the separation variable is
Irrespective of NrFor NtIs provided with
Since the measurement of the temperature is also discrete, neglecting the temperature variation in the measurement interval, assume the temperature to be
T(t)＝T(k) kτ≤t＜(k+1)τ (8)
In the formula (8), tau is the sampling interval time, the time of k tau is not more than t < (k +1) tau is considered separately, and the equivalent time t is*＝t·(T/T0)1.75Substitution into equation (7) can yield:
its form and temperature is T0Constant is the same.
8. The method for dynamic compensation of a humidity sensor according to claim 7,
the diffusion process of the next sampling interval at different temperatures is replaced by the diffusion process at the standard reference temperature for different times, and the replacement relationship is as follows:
τ*＝τ·(T/T0)1.75 (10)
the temperature sampling is discrete, and can be considered as constant temperature in the sampling interval, the temperature in k and k +1 sampling intervals is T (k), and the external environment humidity is not changed into u (k).
9. The method for dynamic compensation of humidity sensor according to any of claims 1-8, wherein the sensor system state space model is transformed into homogeneous equation form during a sampling interval, quantified using a state transition matrix, to determine humidity sensor system transfer function G as a function of temperatureK(Z) a process comprising:
the state space model of the sensor system is transformed into a homogeneous process to introduce a state transition matrix coefficient phi,
in the formula (11), the reaction mixture is,
the above equation is the temperature T at which the time interval is the sampling interval τ and the temperature is constant to identify the sensor system0The state transition matrix in the case of (1), temperature difference and T0Time may be equivalent to a change in the sampling interval. While the temperature and input concentration remain unchanged only the sampling interval becomes τ*＝τ·(T(k)/T0)1.75The system state is changed to:
τ*/τ＝(T(k)/T0)1.75 (14)
the state space model of the sensor which changes along with the temperature is sigmaK：
Then there is
The state space model of the sensor which changes along with the temperature is determined to be sigma through the formulaKThe parameter (c) of (c).
10. The method for dynamic compensation of a humidity sensor according to claim 1,
the temperature dependent humidity sensor system transfer function GK(Z) by eliminating the state variable x (k), obtaining a transfer function of y (k) and u (k) as a function of temperature:
thus, the relative humidities rho (k) and t (k) output by the humidity sensors obtain the compensation value rhc (k) of the ambient humidity of the air:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111622564.5A CN114324501A (en) | 2021-12-28 | 2021-12-28 | Dynamic compensation method for humidity sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111622564.5A CN114324501A (en) | 2021-12-28 | 2021-12-28 | Dynamic compensation method for humidity sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114324501A true CN114324501A (en) | 2022-04-12 |
Family
ID=81014951
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111622564.5A Pending CN114324501A (en) | 2021-12-28 | 2021-12-28 | Dynamic compensation method for humidity sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114324501A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005006859A1 (en) * | 2005-02-15 | 2006-08-17 | Vogt Electronic Components Gmbh | Humidification measuring system for use in vehicle, has temperature compensation mechanism providing temperature corrected output signal corresponding to different behavior during change of temperature or humidification condition of areas |
| US20080208503A1 (en) * | 2007-02-12 | 2008-08-28 | Vaisala Oyj | Method and device for compensating temperature dependencies |
| CN105223241A (en) * | 2015-09-18 | 2016-01-06 | 南京信息工程大学 | A kind of compensation method of humidity sensor |
| CN106198651A (en) * | 2016-08-31 | 2016-12-07 | 成都市和平科技有限责任公司 | A kind of high accuracy humidity sensor |
| US20180209929A1 (en) * | 2015-08-17 | 2018-07-26 | Denso Corporation | Humidity detector |
| CN110988054A (en) * | 2019-12-10 | 2020-04-10 | 朱义法 | Temperature compensation structure and compensation method of capacitive humidity sensor |
-
2021
- 2021-12-28 CN CN202111622564.5A patent/CN114324501A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102005006859A1 (en) * | 2005-02-15 | 2006-08-17 | Vogt Electronic Components Gmbh | Humidification measuring system for use in vehicle, has temperature compensation mechanism providing temperature corrected output signal corresponding to different behavior during change of temperature or humidification condition of areas |
| US20080208503A1 (en) * | 2007-02-12 | 2008-08-28 | Vaisala Oyj | Method and device for compensating temperature dependencies |
| US20180209929A1 (en) * | 2015-08-17 | 2018-07-26 | Denso Corporation | Humidity detector |
| CN105223241A (en) * | 2015-09-18 | 2016-01-06 | 南京信息工程大学 | A kind of compensation method of humidity sensor |
| CN106198651A (en) * | 2016-08-31 | 2016-12-07 | 成都市和平科技有限责任公司 | A kind of high accuracy humidity sensor |
| CN110988054A (en) * | 2019-12-10 | 2020-04-10 | 朱义法 | Temperature compensation structure and compensation method of capacitive humidity sensor |
Non-Patent Citations (4)
| Title |
|---|
| GUOHONG CHEN 等: "Adaptive Nonlinearity Compensation System for Integrated Temperature and Moisture Sensor", MICROMACHINES, vol. 10, no. 12, 13 December 2019 (2019-12-13), pages 1 - 11 * |
| WEI XU 等: "Modeling and Analysis of Adaptive Temperature Compensation for Humidity Sensors", ELECTRONICS, vol. 8, no. 4, 11 April 2019 (2019-04-11), pages 1 - 14 * |
| 柏文奇 等: "土壤湿度传感器非线性误差补偿方法", 中国检验检测, vol. 28, no. 2, 26 March 2020 (2020-03-26), pages 30 - 33 * |
| 赵燕东 等: "SWR土壤湿度传感器温漂特性与补偿研究", 农业机械学报, vol. 50, no. 8, 31 August 2019 (2019-08-31), pages 257 - 263 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105823907B (en) | Parallel plate capacitor type mems accelerometer built-in self-test circuit and self-test method | |
| CN102590450A (en) | Array type smell detecting element based on MEMS (Micro Electro Mechanical System) technology | |
| JPH02171647A (en) | Measurement method and sensor for measuring relative density of gas or steam | |
| CN111948273B (en) | Method and device for establishing temperature compensation model of gas sensor and measuring gas concentration | |
| CN110220945B (en) | Full-range temperature compensation method of semiconductor gas sensor | |
| US5303167A (en) | Absolute pressure sensor and method | |
| Biswal et al. | Design and fabrication of an inexpensive capacitive humidity sensor for smart sub-station automation | |
| CN114324501A (en) | Dynamic compensation method for humidity sensor | |
| CN112326882A (en) | Air quality sensor processing method and device | |
| CN102095782A (en) | Gas on-line detection device based on micro-nano carbon nano tube film three-electrode | |
| CN114184648B (en) | Moisture content calibration method for resistance-capacitance humidity sensor | |
| Sarma et al. | Design and characterisation of a temperature compensated relative humidity measurement system with on line data logging feature | |
| Legendre et al. | High-resolution micro-pirani pressure sensor with transient response processing and time-constant evaluation | |
| Rajendran et al. | Measurement of conductivity of liquids using AT89C55WD microcontroller | |
| Kusumawardani et al. | Water-Bath Calibration Device with Data Storage Using Six Thermocouple Sensor | |
| US6220076B1 (en) | Differential gas analyzer | |
| RU2556288C2 (en) | Analyser of total pressure, density and partial pressure of water vapours in low vacuum | |
| US20030016725A1 (en) | Thermocouple device | |
| CN105783993A (en) | Temperature and relative humidity integrated sensor | |
| US20240219344A1 (en) | System and method for self-calibrating of ion selective electrodes based on differential voltage measurement | |
| Ivanov et al. | Compensation of the Temperature Impact on the Characteristics of a Titania-Silica Thin Film Humidity Sensor Element | |
| CN109990804A (en) | The self-correcting positive circuit of sensor circuit temperature drift based on analog multiplier | |
| TW201202692A (en) | Measurement device and measurement method utilizing the same | |
| Cięszczyk | Sensors signal processing under influence of environmental disturbances | |
| Liu et al. | The design of low-power and high-precision electronic scale based on single chip |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |