A full-temperature-range compensation method for a MEMS high-precision resonant pressure sensor

Abstract

This invention provides a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor, comprising the following steps: acquiring data from the resonant pressure sensor under test at different operating temperature points T. i and the corresponding pressure points P within the range. j The pressure measurement frequency data X ij With temperature and voltage data Y ij ; X, the pressure measurement frequency data of the resonant pressure sensor ij With temperature and voltage data Y ij Normalization is performed separately to obtain x ij With y ij The standard pressure source output pressure P of the environment where the resonant pressure sensor under test is located. j 、and P j The corresponding x ij and y ij A three-dimensional data matrix table is created, and the full-temperature-range compensation algorithm model is input. Three-dimensional surface fitting calculations are then performed to obtain all coefficients K of the full-temperature-range compensation algorithm model. mn Compared with traditional compensation algorithms, this invention normalizes the raw output data of the resonant pressure sensor, thereby reducing the complexity of data calculation in the compensation algorithm, improving the accuracy of data calculation, and achieving better compensation results throughout the entire operating temperature range of the resonant pressure sensor.

Description

Technical Field

[0001] This invention relates to the field of measurement and testing technology, specifically to a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor. Background Technology

[0002] Resonant pressure sensors have advantages such as high precision, high resolution, and high long-term stability, and are widely used in aerospace, meteorological monitoring, and industrial control.

[0003] Because resonant pressure sensors have a wide operating temperature range, temperature drift is a key issue currently faced by high-precision resonant pressure sensors. The introduction of temperature error directly affects the measurement accuracy of resonant pressure sensors. Therefore, temperature compensation is needed to reduce the impact of temperature changes on the accuracy of resonant pressure sensors.

[0004] Temperature compensation methods are generally divided into hardware compensation and software compensation. Hardware compensation typically involves adding a temperature compensation structure to the resonant pressure sensor core to reduce the impact of temperature drift. Hardware compensation is highly efficient, but it is difficult to design and lacks flexibility.

[0005] Software compensation offers advantages such as high flexibility and low design complexity, and can further enhance the compensation effect based on hardware compensation. For resonant pressure sensors, software compensation typically uses a data matrix table composed of frequency, temperature, and air pressure data, and performs temperature compensation through appropriate algorithms.

[0006] The core of software compensation is the compensation algorithm. For high-precision resonant pressure sensors, the data processing procedure and the order of the fitting formula in the compensation algorithm need to be specially designed. Existing high-precision resonant pressure sensor compensation algorithms suffer from complex data processing, resulting in low accuracy and directly affecting the sensor's measurement accuracy. Summary of the Invention

[0007] This invention addresses the measurement accuracy problem of resonant pressure sensors by providing a full-temperature-range compensation method for MEMS high-precision resonant pressure sensors. The method normalizes the data, reducing the complexity of data calculation in the compensation algorithm, thereby improving the measurement accuracy of the resonant pressure sensor, reducing output error, and has been experimentally verified. The algorithm demonstrates extremely high compensation accuracy across the entire operating temperature range of the resonant pressure sensor, exhibiting excellent compensation performance.

[0008] This invention provides a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor, comprising the following steps:

[0009] S1. Determine the calibration temperature points T1, T2, ..., T of the resonant pressure sensor under test. t Pressure points P1, P2, ..., P p ;

[0010] S2. Connect the resonant pressure sensor under test to the test calibration system and measure all temperature points T. i and corresponding to all pressure points P j The pressure measurement frequency data X of the resonant pressure sensor under test ij Temperature and voltage data Y ij Where i = 1, 2, ..., t; j = 1, 2, ..., p;

[0011] S3, Transfer the pressure measurement frequency data X ij Temperature and voltage data Y ij Normalization was performed to obtain normalized pressure measurement frequency data x. ij With normalized temperature and voltage data y ij ;

[0012] S4, Using pressure point P j Normalized pressure measurement frequency data x ij and normalized temperature and voltage data y ij A three-dimensional data matrix table is created, and then the three-dimensional data matrix table is input into the full-temperature-range compensation algorithm model to perform three-dimensional surface fitting, thereby obtaining the coefficients K of the full-temperature-range compensation algorithm model. mn ;

[0013] S5, using K mn A full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor was developed, which performs full-temperature-range compensation for the resonant pressure sensor under test.

[0014] The MEMS high-precision resonant pressure sensor full-temperature range compensation method described in this invention, as a preferred embodiment, in step S3, the pressure measurement frequency data X... ij The normalization method is any one of the following:

[0015] x ij =X ij -X1';

[0016] x ij =X ij / X1';

[0017] x ij =(X ij -X1') / X'2;

[0018] x ij =X ij / X1'-X'2;

[0019] y ij Y ij The relationship between them and x ij X ijThe ways they are associated are the same.

[0020] The MEMS high-precision resonant pressure sensor full-temperature range compensation method described in this invention, as a preferred embodiment, X1' is X ij The mean, maximum value, minimum value, or the average of the maximum and minimum values, or the population standard deviation or the sample standard deviation.

[0021] The present invention discloses a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor, wherein, as a preferred embodiment, X1' and X... ij The relationship between them can be any of the following:

[0022] X1'=Average(X ij );

[0023] X1'=Max(X ij );

[0024] X1'=Min(X ij );

[0025] X1'=(Max(X ij )+Min(X ij )) / 2;

[0026]

[0027]

[0028] The present invention discloses a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor, wherein, as a preferred embodiment, X'2, X... ij Between, Y1', Y ij Between and Y2', Y ij The relationships between them are all related to X1' and X. ij The ways they are associated are the same.

[0029] The MEMS high-precision resonant pressure sensor full-temperature range compensation method described in this invention, as a preferred embodiment, has the following full-temperature range compensation algorithm model in step S4:

[0030]

[0031] Where m is all natural numbers between 0 and M, and n is all natural numbers between 0 and N.

[0032] In the MEMS high-precision resonant pressure sensor full-temperature range compensation method described in this invention, as a preferred embodiment, M is any natural number between 2 and 10, and N is any natural number between 2 and 10.

[0033] The MEMS high-precision resonant pressure sensor full-temperature range compensation method described in this invention, as a preferred embodiment, in step S5,

[0034]

[0035] Where x is the normalized data of the actual pressure measurement frequency, y is the normalized data of the actual temperature measurement voltage, and Pressure is the pressure measurement value after full-temperature compensation.

[0036] The MEMS high-precision resonant pressure sensor full-temperature range compensation method described in this invention, as a preferred embodiment, includes a test calibration system comprising a high and low temperature chamber and a standard pressure source controller.

[0037] The resonant pressure sensor under test is placed in a high and low temperature chamber and connected to a DC power supply and a standard pressure source controller. The standard pressure source controller is connected to both the vacuum pump and the gas cylinder.

[0038] The MEMS high-precision resonant pressure sensor full-temperature-range compensation method described in this invention, as a preferred embodiment, further includes a test calibration system that includes a general-purpose frequency counter connected to the pressure measurement frequency output port of the resonant pressure sensor under test and a digital multimeter connected to the temperature measurement voltage output port of the resonant pressure sensor under test.

[0039] This invention employs a polynomial model, which improves the accuracy of compensation while maintaining the convenience of the algorithm. This invention does not require the use of a large amount of data for training simulation, nor does it require the use of complex Lagrange multipliers, making it more convenient, simple, and efficient in use.

[0040] This invention clarifies a normalization method in data processing. By normalizing the constraints and combining it with a polynomial model, the accuracy reaches the level of parts per million, improving the compensation accuracy while maintaining the simplicity of the algorithm.

[0041] The present invention has the following advantages:

[0042] This invention normalizes the data, reducing the complexity of data calculation in the compensation algorithm, improving the measurement accuracy of the resonant pressure sensor, reducing output error, and has been experimentally verified. The algorithm has extremely high compensation accuracy and excellent compensation effect throughout the entire operating temperature range of the resonant pressure sensor. Attached Figure Description

[0043] Figure 1 This diagram illustrates the connection between a high-precision resonant pressure sensor prototype and a standard pressure controller, representing a full-temperature-range compensation method for a MEMS high-precision resonant pressure sensor.

[0044] Figure 2This is a flowchart of a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor. Detailed Implementation

[0045] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0046] Example 1

[0047] like Figures 1-2 As shown, a full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor includes the following steps:

[0048] (1) Determine the calibration temperature points T1, T2…T of the resonant pressure sensor under test. t With pressure points P1, P2...P p .

[0049] (2) Connect the resonant pressure sensor under test to the test calibration system and measure all temperature points T. i (i = 1, 2, ..., t) corresponds to all pressure points P j The pressure measurement frequency data X of the resonant pressure sensor under test (j = 1, 2, ..., p) ij With temperature and voltage data Y ij .

[0050] (3) The pressure measurement frequency data X of the resonant pressure sensor ij With temperature and voltage data Y ij Normalization is performed separately to obtain x ij With y ij .

[0051] (4) The standard pressure source output pressure P of the environment where the resonant pressure sensor under test is located. j 、and P j Corresponding x ij and y ij A three-dimensional data matrix table is created, and the full-temperature-range compensation algorithm model is input. Three-dimensional surface fitting calculations are then performed to obtain all coefficients K of the full-temperature-range compensation algorithm model. mn .

[0052] In step (3), the pressure measurement frequency data X of the resonant pressure sensor is... ij With temperature and voltage data Y ij Normalization was performed separately to obtain x. ij With y ij The characteristic is that the x ij With X ij There are the following four association methods, x ijIt can be calculated using any one of the four association methods:

[0053] x ij =X ij -X1';x ij =X ij / X1';

[0054] x ij =(X ij -X1') / X'2;x ij =X ij / X1'-X'2

[0055] y ij Y ij The relationship between them and x ij X ij The association methods between them are the same, y ij It can be calculated using any one of the four association methods.

[0056] X1' and X ij There are 6 possible associations between them, and X1' can be calculated from any one of these 6 association methods:

[0057] X1'=Average(X ij ), mean; X1' = Max(X ij ), maximum value; X1' = Min(X ij ), minimum value;

[0058] X1'=(Max(X ij )+Min(X ij )) / 2, the average of the maximum and minimum values;

[0059] Overall standard deviation;

[0060] Sample standard deviation;

[0061] X'2、X ij Between, Y1', Y ij Between and Y2', Y ij The relationships between them are all related to X1' and X. ij The association methods among them are the same, and X'2, Y1', and Y2' can be calculated from any one of the six association methods.

[0062] In step (4), the preset algorithm for the full-temperature compensation algorithm model is as follows:

[0063]

[0064] m is any natural number from 0 to M, n is any natural number from 0 to N. M is any natural number from 2 to 10, and N is any natural number from 2 to 10.

[0065] In this embodiment, the high-precision resonant pressure sensor is calibrated across the entire temperature range, and the temperature T at each calibration point is measured. i Corresponding to all calibrated pressure points P j The pressure measurement frequency data X of the resonant pressure sensor under test ij With temperature measurement output Y ij .

[0066] Output the pressure measurement frequency X ij With temperature measurement voltage output Y ij Normalization was performed separately:

[0067] X1'=(Max(X ij )+Min(X ij )) / 2, Y1'=(Max(Y ij )+Min(Y ij )) / 2

[0068]

[0069]

[0070] x ij =(X ij -X1') / X'2,y ij =(Y ij -Y1') / Y2'

[0071] The standard pressure source output pressure P of the environment where the resonant pressure sensor under test is located j 、and P j Corresponding x ij and y ij A three-dimensional data matrix table is created, and the full-temperature-range compensation algorithm model is input. Three-dimensional surface fitting calculations are then performed to obtain all coefficients K of the full-temperature-range compensation algorithm model. mn .

[0072]

[0073] Where m is any natural number from 0 to M, and n is any natural number from 0 to N. M = 3, N = 5.

[0074] In this embodiment, the calibration temperature point T (-55℃, -25℃, 0℃, 25℃, 55℃, 85℃) and calibration pressure point P (150kPa, 130kPa, 110kPa, 90kPa, 70kPa, 50kPa, 30kPa, 10kPa, 1kPa) of the high-precision resonant pressure sensor under test are determined.

[0075] See appendix Figure 1 As shown, a high-precision resonant pressure sensor prototype is connected to a standard pressure controller and placed inside a high-low temperature chamber. A power supply, a general-purpose frequency counter, and a digital multimeter are also connected to power the prototype, acquire the pressure measurement frequency, and acquire the temperature and voltage measurements, respectively. The output signals of the sensor prototype are: one channel of pressure measurement frequency data X and one channel of temperature and voltage measurement data Y.

[0076] The pressure measurement frequency output X and the temperature measurement voltage output Y are normalized respectively. P is then combined with the corresponding X, Y and x, y to form a data matrix:

[0077] Table 1. Raw output and normalized data matrix of the resonant pressure sensor

[0078]

[0079]

[0080]

[0081] The data obtained by normalizing the original data from the calibration pressure point and the resonant pressure sensor under test is then substituted into the full-temperature-range compensation algorithm model:

[0082]

[0083] Where m is any natural number from 0 to 3, and n is any natural number from 0 to 5.

[0084] Using mathematical fitting software, the surface fitting method was employed to fit the surface and solve for K. mn Data matrix:

[0085] K01 = 2.78720554E+00 K11 = -1.03695190E-01 K21 = 4.82112795E-03 K31 = -1.42751577E-04 K02 = -2.56044394E-02 K12 = -1.73929366E-02 K22 = 1.49671816E-03 K32 = -2.33165094E-04 K03 = -5.64136898E-03 K13 = 1.89457554E-02 K23 = -8.91186640E-04 K33 = 8.67814700E-04 K04 = 4.03063223E-03 K14 = -4.22401400E-03 K24 = -8.17994470E-04 K34 = 9.68120810E-05 K05 = -9.47032640E-04 K15 = -1.70446523E-03 K25 = 4.23496194E-04 K35 = -3.55093780E-04

[0086] K mn The full-temperature-range compensation algorithm is obtained by substituting the pressure measurement frequency output X and temperature measurement voltage output Y of the resonant pressure sensor under test into the full-temperature-range compensation algorithm. This forms the pressure output matrix of the resonant pressure sensor under test.

[0087]

[0088] The verification data shows that the pressure value output by the resonant pressure sensor using this compensation algorithm differs from that of the standard pressure source by a maximum of 0.0011 kPa across the entire temperature range, achieving an accuracy of 0.00074% FS, demonstrating excellent compensation performance.

[0089] The above embodiments use a high-precision resonant pressure sensor with a pressure range of 0–150 kPa and a temperature range of -55–85°C. The compensation algorithm proposed in this invention normalizes the temperature measurement frequency output and temperature measurement voltage output of the resonant pressure sensor, reducing the computational difficulty and improving the accuracy of the compensation algorithm. This algorithm provides excellent compensation throughout the entire operating temperature range of the resonant pressure sensor, ensuring the full-temperature measurement accuracy of the high-precision resonant pressure sensor.

[0090] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for full-temperature-range compensation of a high-precision MEMS resonant pressure sensor, characterized in that: Includes the following steps: S1. Determine the calibration temperature point of the resonant pressure sensor under test. , …、 Pressure point , … ; S2. Connect the resonant pressure sensor under test to the test calibration system and measure all temperature points. and corresponding all pressure points The pressure measurement frequency data of the resonant pressure sensor under test described below Temperature and voltage measurement data Where i = 1, 2, ..., t; j = 1, 2, ..., p; S3, the pressure measurement frequency data The temperature and voltage data Normalized pressure measurement frequency data were obtained by performing normalization processing on each data point. With normalized temperature and voltage data ; S4, Applying pressure points Normalized pressure measurement frequency data and normalized temperature and voltage data A three-dimensional data matrix table is created, and the coefficients of the full-temperature-range compensation algorithm model are obtained by substituting the three-dimensional data matrix table into the full-temperature-range compensation algorithm model. ; The full-temperature-range compensation algorithm model is as follows: ； Where m is all natural numbers between 0 and M, and n is all natural numbers between 0 and N; S5, Use Perform full-temperature compensation on the resonant pressure sensor under test; ； in, x The data is normalized based on the actual pressure measurement frequency. y The data is the normalized value of the actual temperature measurement voltage, and Pressure is the pressure measurement value after full temperature range compensation. A method for full-temperature-range compensation of a high-precision MEMS resonant pressure sensor has been developed.

2. The full-temperature-range compensation method for a MEMS high-precision resonant pressure sensor according to claim 1, characterized in that: In step S3, the pressure measurement frequency data The normalization method is any one of the following: ； ； ； ； , The relationship between them and , The association methods between them are the same; for The mean, maximum value, minimum value, or the average of the maximum and minimum values, or the population standard deviation or the sample standard deviation; , The relationship between them and , The ways they are associated are the same.

3. The full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor according to claim 2, characterized in that: and The relationship between them can be any of the following: ； ； ； ； ； 。 4. The full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor according to claim 2, characterized in that: , Between and , The ways in which they are related are all the same as , The ways they are associated are the same.

5. The full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor according to claim 1, characterized in that: M is any natural number between 2 and 10, and N is any natural number between 2 and 10.

6. The full-temperature-range compensation method for a MEMS high-precision resonant pressure sensor according to claim 1, characterized in that: The test calibration system includes a high and low temperature chamber and a standard pressure source controller; The resonant pressure sensor under test is placed in the high and low temperature chamber and connected to the DC power supply and the standard pressure source controller. The standard pressure source controller is connected to both the vacuum pump and the gas cylinder.

7. A full-temperature-range compensation method for a high-precision MEMS resonant pressure sensor according to claim 6, characterized in that: The test calibration system also includes a general-purpose frequency counter connected to the pressure measurement frequency output port of the resonant pressure sensor under test and a digital multimeter connected to the temperature measurement voltage output port of the resonant pressure sensor under test.

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