Three-dimensional compensation method for absolute pressure, differential pressure and temperature

Abstract

The application provides a kind of absolute pressure, differential pressure and temperature three-dimensional compensation method, comprising: the pressure sensing module is placed in the oven, the absolute pressure gas path and differential pressure gas path of pressure sensing module are connected with the absolute pressure control channel and differential pressure control channel of standard pressure controller respectively, and the pressure of differential pressure channel is taken as the reference of absolute pressure channel;Complete all absolute pressure test pressure points and differential pressure test pressure points under each test temperature point data test;Based on the absolute pressure data and temperature data of absolute pressure sensor and the differential pressure data, temperature data and absolute pressure reference data of differential pressure sensor, surface fitting modeling is carried out, and the fitted absolute pressure calculation model and the fitted differential pressure calculation model are calculated and obtained;The real-time measured absolute pressure data, differential pressure data and temperature data are substituted into the fitted differential pressure calculation model, and the absolute pressure, differential pressure and temperature three-dimensional compensation are completed.The technical scheme of the application is used to solve the technical problem that the pressure sensor in the prior art is prone to temperature drift, which affects the precision of the product.

Description

Technical Field

[0001] This invention relates to the field of pressure sensing technology, and in particular to a three-dimensional compensation method for absolute pressure, differential pressure and temperature. Background Technology

[0002] Pressure sensing modules based on the absolute-differential pressure composite measurement principle, primarily using silicon piezoresistive pressure sensors, can measure absolute and differential pressure data in real time and convert them into information such as barometric altitude and indicated airspeed. They are widely used in various moving vehicles in aerospace, unmanned equipment, ground equipment, and consumer electronics. For many low-speed moving vehicles, differential pressure measurement requires the configuration of differential pressure sensors (generally below 5 kPa) to achieve low indicated airspeed measurement. With the rapid development of various technologies, the measurement accuracy requirements for this type of product are also increasing.

[0003] The core measuring unit of this type of product is a silicon piezoresistive pressure sensor. This type of sensor has the drawback of being temperature sensitive and prone to temperature drift, which affects the accuracy of the product. On the other hand, for differential pressure sensors required for use in low-speed moving vehicles, the pressure measurement output values ​​also differ under different absolute pressure application environments. Summary of the Invention

[0004] This invention provides a three-dimensional compensation method for absolute pressure, differential pressure, and temperature, which can solve the technical problem that pressure sensors in the prior art are prone to temperature drift, thus affecting product accuracy.

[0005] This invention provides a three-dimensional compensation method for absolute pressure, differential pressure, and temperature. The method includes: setting multiple absolute pressure test points, multiple differential pressure test points, and multiple test temperature points; during calibration testing, placing a pressure sensing module in a temperature chamber, with the absolute pressure and differential pressure gas paths of the pressure sensing module connected to the absolute pressure control channel and differential pressure control channel of a standard pressure controller, respectively, and the differential pressure channel using the pressure of the absolute pressure channel as a reference; controlling the temperature chamber to reach the set first test temperature point, maintaining the temperature at this point until the internal temperature of the pressure sensing module reaches and stabilizes at the set temperature; after the maintenance time is reached, performing a pressure test on the pressure sensing module; controlling the standard pressure controller to reach each absolute pressure test point; performing tests and data acquisition at all differential pressure test points at each absolute pressure test point; and controlling the temperature chamber to reach the set second test temperature point. Repeat the above steps until all absolute pressure and differential pressure test data are collected at each test temperature point. Absolute pressure and temperature data from the absolute pressure sensor, and differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor are acquired. Based on these data, surface fitting modeling is performed to calculate the fitted absolute pressure and differential pressure calculation models. The pressure sensing module measures different absolute pressure, differential pressure, and temperature data in real time. Substituting the real-time measured absolute pressure and temperature data into the fitted absolute pressure calculation model yields the compensated absolute pressure test data, and substituting the real-time measured absolute pressure, differential pressure, and temperature data into the fitted differential pressure calculation model yields the compensated differential pressure test data, thus completing the three-dimensional compensation of absolute pressure, differential pressure, and temperature.

[0006] Further, the pressure sensor module is kept at the first test temperature until its internal temperature reaches and stabilizes. After the holding time is reached, a pressure test is performed on the pressure sensor module. The standard pressure controller is then controlled to reach each absolute pressure test point. At each absolute pressure test point, all differential pressure test points are tested and data is collected. Specifically, this includes: keeping the pressure sensor module at the first test temperature until its internal temperature reaches and stabilizes; after the holding time is reached, a pressure test is performed on the pressure sensor module; controlling the standard pressure controller to reach the first absolute pressure test point; at the first absolute pressure test point, controlling the standard pressure controller to reach the first differential pressure test point; collecting real-time data from the absolute pressure sensor and differential pressure sensor; controlling the standard pressure controller to reach the second differential pressure test point; collecting real-time data from the absolute pressure sensor and differential pressure sensor; repeating the above steps, sequentially controlling the standard pressure controller to reach the third differential pressure test point, the fourth differential pressure test point, and so on… At the Nth differential pressure test point, acquire real-time data from the absolute pressure sensor and differential pressure sensor at all differential pressure test points below the first absolute pressure test point; control the standard pressure controller to reach the second absolute pressure test point, and at the second absolute pressure test point, control the standard pressure controller to reach the first differential pressure test point to acquire real-time data from the absolute pressure sensor and differential pressure sensor; control the standard pressure controller to reach the second differential pressure test point to acquire real-time data from the absolute pressure sensor and differential pressure sensor; repeat the above steps, sequentially controlling the standard pressure controller to reach the third differential pressure test point, the fourth differential pressure test point, ..., the Nth differential pressure test point, acquiring real-time data from the absolute pressure sensor and differential pressure sensor at all differential pressure test points below the first absolute pressure test point; repeat the above steps, sequentially controlling the standard pressure controller to reach the third absolute pressure test point, the fourth absolute pressure test point, ..., the Mth absolute pressure test point, completing the testing and data acquisition of all differential pressure test points below each absolute pressure test point.

[0007] Furthermore, the fitted absolute pressure calculation model is as follows: Among them, P 绝压 p is the absolute pressure fitted value. 绝压 The absolute pressure measurement value is t. 绝压 This is the absolute pressure temperature measurement value, K. ab Here, represents the absolute pressure fitting parameters, i represents the absolute pressure fitting order, and j represents the absolute pressure temperature fitting order.

[0008] Furthermore, the absolute pressure fitting order is 5, and the absolute pressure-temperature fitting order is 6.

[0009] Furthermore, the fitted differential pressure calculation model is as follows: Among them, P 差压 p is the differential pressure fitted value. 差压 The differential pressure measurement value is t. 差压This is the differential pressure temperature measurement value, p 绝压基准 K is the absolute pressure reference measurement value. xyz Here, l represents the differential pressure fitting parameters, m represents the differential pressure temperature fitting order, and n represents the absolute pressure reference fitting order.

[0010] Furthermore, the differential pressure fitting order is 5, the differential pressure-temperature fitting order is 6, and the absolute pressure reference order is 4.

[0011] Furthermore, the test pressure points set for the absolute pressure sensor are 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, and 100 kPa, and the test pressure points set for the differential pressure sensor are 0 kPa, 0.5 kPa, 1 kPa, 1.5 kPa, 2 kPa, 2.5 kPa, 3 kPa, 3.5 kPa, 4 kPa, 4.5 kPa, and 5 kPa, and the test temperature points are -55℃, -35℃, -15℃, 5℃, 25℃, 45℃, 65℃, and 85℃.

[0012] Furthermore, the differential pressure channel, based on the pressure of the absolute pressure channel, specifically includes: the positive pressure end of the differential pressure sensor is connected to the differential pressure control channel of the standard pressure controller, and the negative pressure end of the differential pressure sensor is connected to the absolute pressure control channel of the standard pressure controller.

[0013] Furthermore, the pressure sensing module is a silicon piezoresistive pressure sensor with integrated temperature sensor components.

[0014] Furthermore, surface fitting modeling is performed using MATLAB based on the absolute pressure and temperature data from the absolute pressure sensor and the differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor.

[0015] This invention provides a three-dimensional compensation method for absolute pressure, differential pressure, and temperature. This method achieves compensation of three-dimensional data (absolute pressure, differential pressure, and temperature). Using the input pressure and output voltage values ​​of the absolute pressure and differential pressure sensors, as well as the module's operating temperature, as variables, a surface fitting mathematical model is constructed. After measuring various data points and substituting them into the mathematical model, the precise pressure value of the measured point can be quickly and easily calculated. Furthermore, after establishing the mathematical model, the pressure sensing module can be calibrated to obtain the compensated accuracy value. Compared with existing technologies, the three-dimensional compensation method for absolute pressure, differential pressure, and temperature provided by this invention can effectively improve the measurement accuracy of existing absolute pressure-differential pressure composite measurement pressure sensing modules in various application scenarios. Attached Figure Description

[0016] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0017] Figure 1 A flowchart of a three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to a specific embodiment of the present invention is shown. Detailed Implementation

[0018] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0020] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0021] like Figure 1 As shown in the figure, a three-dimensional compensation method for absolute pressure, differential pressure, and temperature is provided according to a specific embodiment of the present invention. This method includes: setting multiple absolute pressure test pressure points, multiple differential pressure test pressure points, and multiple test temperature points; during calibration testing, a pressure sensing module is placed in a temperature chamber, and the absolute pressure gas path and differential pressure gas path of the pressure sensing module are respectively connected to the absolute pressure control channel and differential pressure control channel of a standard pressure controller, with the differential pressure channel using the pressure of the absolute pressure channel as a reference; controlling the temperature chamber to reach the set first test temperature point, maintaining the temperature at the first test temperature point until the internal temperature of the pressure sensing module reaches the set temperature point and stabilizes; after the maintenance time is reached, a pressure test is performed on the pressure sensing module; the standard pressure controller is controlled to reach each absolute pressure test pressure point; tests and data acquisition are performed at all differential pressure test pressure points at each absolute pressure test pressure point; and the temperature chamber is controlled to reach the set second... Repeat the above steps at each test temperature point until all absolute pressure and differential pressure test data are collected at each test temperature point. Acquire absolute pressure and temperature data from the absolute pressure sensor, and differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor. Perform surface fitting modeling based on these data, and calculate the fitted absolute pressure and differential pressure calculation models. The pressure sensing module measures different absolute pressure, differential pressure, and temperature data in real time. Substituting the real-time measured absolute pressure and temperature data into the fitted absolute pressure calculation model yields compensated absolute pressure test data, and substituting the real-time measured absolute pressure, differential pressure, and temperature data into the fitted differential pressure calculation model yields compensated differential pressure test data, thus completing three-dimensional compensation for absolute pressure, differential pressure, and temperature.

[0022] This configuration provides a three-dimensional compensation method for absolute pressure, differential pressure, and temperature. This method compensates for the three-dimensional data of absolute pressure, differential pressure, and temperature. Using the input pressure and output voltage values ​​of the absolute pressure and differential pressure sensors, as well as the module's operating temperature, as variables, a surface fitting mathematical model is constructed. After measuring the various data points, substituting them into the mathematical model allows for quick and easy calculation of the precise pressure value at the measured point. Furthermore, the pressure sensing module can be calibrated after establishing the mathematical model to obtain the compensated accuracy. Compared with existing technologies, the three-dimensional compensation method for absolute pressure, differential pressure, and temperature provided by this invention can effectively improve the measurement accuracy of existing absolute pressure-differential pressure composite measurement pressure sensing modules in various application scenarios.

[0023] Specifically, in this invention, to achieve three-dimensional compensation for absolute pressure, differential pressure, and temperature, it is first necessary to set multiple absolute pressure test points, multiple differential pressure test points, and multiple test temperature points. In this invention, because silicon piezoresistive pressure sensors exhibit a significant temperature effect and large differences in output signal across a wide operating temperature range, it is recommended to integrate temperature sensor components, such as platinum resistance thermometers or temperature diodes, into the silicon piezoresistive pressure sensor. This allows for the acquisition of temperature information near the core sensor components, enabling full-temperature compensation for the silicon piezoresistive pressure sensing module. The test pressure points for the absolute pressure sensor are 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, and 100 kPa. The test pressure points for the differential pressure sensor are 0 kPa, 0.5 kPa, 1 kPa, 1.5 kPa, 2 kPa, 2.5 kPa, 3 kPa, 3.5 kPa, 4 kPa, 4.5 kPa, and 5 kPa. The test temperature points are -55℃, -35℃, -15℃, 5℃, 25℃, 45℃, 65℃, and 85℃. The absolute pressure and differential pressure compensation ranges should cover the pressure range of the pressure sensing module, and the temperature compensation range should cover the operating temperature range of the pressure sensing module. Appropriate test points should be set for the pressure sensing module across the entire pressure range and temperature range. Calibration tests should be completed, and the calibration data should be saved. The pressure sensing module can output specific pressure and temperature values, as well as pressure-voltage and temperature-voltage values, all of which can be used as the basis for compensation calculations.

[0024] Furthermore, after setting multiple absolute pressure test points, multiple differential pressure test points, and multiple test temperature points, during the calibration test, the pressure sensing module is placed in a temperature chamber. The absolute pressure air path and differential pressure air path of the pressure sensing module are connected to the absolute pressure control channel and differential pressure control channel of the standard pressure controller, respectively. The differential pressure channel uses the pressure of the absolute pressure channel as a reference. Specifically, in this invention, the differential pressure channel using the pressure of the absolute pressure channel as a reference specifically includes: the positive pressure end of the differential pressure sensor is connected to the differential pressure control channel of the standard pressure controller, and the negative pressure end of the differential pressure sensor is connected to the absolute pressure control channel of the standard pressure controller.

[0025] After connecting the pressure sensing module to the standard pressure controller, the temperature chamber can be controlled to reach the set first test temperature point. The chamber is then kept at this temperature until the internal temperature of the pressure sensing module reaches and stabilizes at the set temperature. After the holding time is reached, a pressure test is performed on the pressure sensing module. The standard pressure controller is then controlled to reach each absolute pressure test point. At each absolute pressure test point, all differential pressure test points are tested and data is collected. The temperature chamber is then controlled to reach the set second test temperature point. The above steps are repeated until all absolute and differential pressure test points at each test temperature point are tested.

[0026] In this invention, the process involves maintaining a temperature at the first test temperature point until the internal temperature of the pressure sensing module reaches and stabilizes at the set temperature. After the maintenance time is reached, a pressure test is performed on the pressure sensing module. The standard pressure controller is then controlled to reach each absolute pressure test point. Specifically, the process includes: maintaining a temperature at the first test temperature point until the internal temperature of the pressure sensing module reaches and stabilizes at the set temperature; performing a pressure test on the pressure sensing module after the maintenance time is reached; controlling the standard pressure controller to reach the first absolute pressure test point; at the first absolute pressure test point, controlling the standard pressure controller to reach the first differential pressure test point; and collecting real-time data from the absolute pressure sensor and differential pressure sensor; controlling the standard pressure controller to reach the second differential pressure test point; and collecting real-time data from the absolute pressure sensor and differential pressure sensor; repeating the above steps sequentially to control the standard pressure controller to reach the third differential pressure test point, the fourth differential pressure test point, and so on. …At the Nth differential pressure test point, acquire real-time data from the absolute pressure sensor and differential pressure sensor at all differential pressure test points under the first absolute pressure test point; control the standard pressure controller to reach the second absolute pressure test point, and at the second absolute pressure test point, control the standard pressure controller to reach the first differential pressure test point to acquire real-time data from the absolute pressure sensor and differential pressure sensor; control the standard pressure controller to reach the second differential pressure test point to acquire real-time data from the absolute pressure sensor and differential pressure sensor; repeat the above steps, sequentially controlling the standard pressure controller to reach the third differential pressure test point, the fourth differential pressure test point, …, the Nth differential pressure test point to acquire real-time data from the absolute pressure sensor and differential pressure sensor at all differential pressure test points under the first absolute pressure test point; repeat the above steps, sequentially controlling the standard pressure controller to reach the third absolute pressure test point, the fourth absolute pressure test point, …, the Mth absolute pressure test point to complete the testing and data acquisition of all differential pressure test points under each absolute pressure test point.

[0027] Furthermore, after completing the data testing at all absolute pressure and differential pressure test points at each test temperature, absolute pressure and temperature data from the absolute pressure sensor, and differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor were collected. Based on these data, surface fitting modeling was performed, and the fitted absolute pressure calculation model and the fitted differential pressure calculation model were obtained. In a specific embodiment of this invention, surface fitting modeling was performed using MATLAB based on the absolute pressure and temperature data from the absolute pressure sensor, and the differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor.

[0028] The pressure sensing module performs surface fitting on calibration data across the entire pressure and temperature range. For both absolute pressure and differential pressure sensors, appropriate fitting orders are determined (e.g., i-th order for absolute pressure, j-th order for absolute pressure and temperature, l-th order for differential pressure, m-th order for differential pressure and temperature, and n-th order for absolute pressure reference). The fitting error is optimized, and the K-value of the modeling model is obtained. 绝压 Parameters, K 差压 parameter.

[0029] The fitted absolute pressure calculation model is as follows: Among them, P 绝压 p is the absolute pressure fitted value. 绝压 The absolute pressure measurement value is t. 绝压 This is the absolute pressure temperature measurement value, K. ab Here, represents the absolute pressure fitting parameters, i represents the absolute pressure fitting order, and j represents the absolute pressure temperature fitting order.

[0030] As a specific embodiment of the present invention, the absolute pressure fitting order is 5, and the absolute pressure temperature fitting order is 6.

[0031] The fitted differential pressure calculation model is as follows Among them, P 差压 p is the differential pressure fitted value. 差压 The differential pressure measurement value is t. 差压 This is the differential pressure temperature measurement value, p 绝压基准 K is the absolute pressure reference measurement value. xyz Here, l represents the differential pressure fitting parameters, m represents the differential pressure temperature fitting order, and n represents the absolute pressure reference fitting order.

[0032] As a specific embodiment of the present invention, the differential pressure fitting order is 5, the differential pressure temperature fitting order is 6, and the absolute pressure reference order is 4.

[0033] After obtaining the fitted absolute pressure calculation model and the fitted differential pressure calculation model, the pressure sensing module measures different absolute pressure data, differential pressure data and temperature data in real time. Substituting the real-time measured absolute pressure data and temperature data into the fitted absolute pressure calculation model can obtain the compensated absolute pressure compensation test data, and substituting the real-time measured absolute pressure data, differential pressure data and temperature data into the fitted differential pressure calculation model can obtain the compensated differential pressure compensation test data, thus completing the three-dimensional compensation of absolute pressure, differential pressure and temperature.

[0034] Specifically, in this invention, the K of the modeling model 绝压 K 差压Parameter updates are performed by programming the parameters into the control circuit of the pressure sensing module. The module measures different absolute pressure, differential pressure, and temperature data, which are then automatically input into the parameter model to obtain compensated test data. This reduces the impact of temperature and pressure references on pressure measurement accuracy. After parameter programming, the accuracy of the model parameters is verified through a three-temperature test. The test temperatures are -50℃, 20℃, and 80℃, and the test pressure points are consistent with the calibration pressure points. The difference between the pressure test data and the set values ​​is compared to verify the accuracy of the model parameters. If the three-temperature verification error is too large (exceeding the accuracy requirement range), it indicates that the compensation model has failed, and recalibration should be considered, or the repeatability and stability of the pressure sensing module should be evaluated.

[0035] To gain a further understanding of the present invention, the following description is provided in conjunction with... Figure 1 The three-dimensional compensation method for absolute pressure, differential pressure and temperature provided by the present invention will be described in detail.

[0036] like Figure 1 As shown in the figure, a three-dimensional compensation method for absolute pressure, differential pressure, and temperature is provided according to a specific embodiment of the present invention. The absolute pressure-differential pressure composite measurement pressure sensing module selected in this embodiment has an absolute pressure range of 5 kPa to 100 kPa, a differential pressure range of 0 to 5 kPa, and an operating temperature range of -55℃ to 85℃. Both the absolute pressure sensor and the differential pressure sensor in the module output pressure voltage signals, and it also has an integrated temperature-sensing platinum resistance thermometer, which can output the temperature and voltage signals near the pressure sensing core in real time.

[0037] Calibration tests were conducted on the pressure sensing module, and reasonable test points were set. Specifically, the test pressure points set for the absolute pressure sensor were 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, and 100 kPa; the test pressure points set for the differential pressure sensor were 0 kPa, 0.5 kPa, 1 kPa, 1.5 kPa, 2 kPa, 2.5 kPa, 3 kPa, 3.5 kPa, 4 kPa, 4.5 kPa, and 5 kPa; and the test temperature points were -55℃, -35℃, -15℃, 5℃, 25℃, 45℃, 65℃, and 85℃.

[0038] During calibration testing, the pressure sensing module is placed in a temperature chamber. The absolute pressure and differential pressure gas paths of the pressure sensing module are connected to the absolute pressure and differential pressure control channels of the standard pressure controller, respectively. The differential pressure channel uses the pressure of the absolute pressure channel as a reference; that is, the positive pressure end of the differential pressure sensor is connected to the differential pressure control channel of the standard pressure controller, and the negative pressure end of the differential pressure sensor is connected to the absolute pressure control channel of the standard pressure controller. A communication cable is connected to the testing equipment, and measurement data is acquired and saved in real time through a data acquisition board and software.

[0039] The temperature chamber is sequentially controlled to reach the set calibration temperature points. At each calibration temperature point, the temperature is maintained until the internal temperature of the pressure sensing module reaches and stabilizes at the set temperature point, typically for more than one hour. After the maintenance time is reached, a pressure test is performed on the pressure sensing module. The standard pressure controller is controlled to reach each absolute pressure calibration point. At each absolute pressure calibration point, all differential pressure calibration points are tested and data is collected. This process is repeated until all data tests at all absolute and differential pressure calibration points at each test temperature point are completed.

[0040] Through calibration experiments, absolute pressure and temperature data from the absolute pressure sensor, differential pressure and temperature data from the differential pressure sensor, and absolute pressure reference data were collected. These data were then used to perform surface fitting modeling using software such as MATLAB. For the absolute pressure and temperature data from the absolute pressure sensor, fifth-order absolute pressure modeling and sixth-order absolute pressure and temperature modeling were implemented, resulting in 6×7 sets of K absolute pressure parameters (i.e., K...). 00 K 01 K 02 ...K 56 The formula for calculating the absolute pressure after fitting is:

[0041]

[0042] In the formula:

[0043] P 绝压 —Absolute pressure fitted value;

[0044] p 绝压 —Absolute pressure measurement value;

[0045] t 绝压 —Absolute pressure temperature measurement;

[0046] K ab — Absolute pressure fitting parameters.

[0047] Based on the differential pressure data, temperature data, and absolute pressure reference data from the differential pressure sensor, we implemented 5th-order differential pressure modeling, 6th-order differential pressure-temperature modeling, and 4th-order absolute pressure reference modeling, obtaining 6×7×5 sets of K differential pressure parameters (i.e., K). 000 K 001 K 002 ...K 564 The formula for calculating the fitted differential pressure is:

[0048]

[0049] In the formula:

[0050] P 差压 —Differential pressure fitting value;

[0051] p 差压 —Differential pressure measurement value;

[0052] t 差压 —Differential pressure temperature measurement value;

[0053] K xyz —Differential pressure fitting parameters.

[0054] The effectiveness of the calibration test is judged by the fitting residual (the fitting residual is the difference between the value calculated by substituting each test point into the fitting polynomial and the standard pressure value of the test point, which is a criterion for the fitting effect). If the fitting residual of some test points is too large (generally, the criterion is that it exceeds the accuracy requirement range), it indicates that the compensation at that test point has failed and the test point should be recalibrated. If the fitting residual is still too large, it indicates that the performance of the pressure sensing module cannot meet the accuracy requirements.

[0055] The fitted K ab Absolute pressure parameters and K xyz Differential pressure parameters are programmed into the control circuit of the pressure sensing module through software. The pressure sensing module measures different absolute pressure data, differential pressure data, and temperature data, and can automatically input them into the parameter model to obtain compensated test data, which can reduce the influence of temperature, pressure reference, etc. on the accuracy of pressure measurement.

[0056] After the parameters are programmed, the accuracy of the model parameters is verified through a three-temperature test. The test temperatures are -50℃, 20℃, and 80℃, and the test pressure points are consistent with the calibration pressure points. The difference between the pressure test data and the set values ​​is compared to verify the accuracy of the model parameters. If the three-temperature verification error is too large (exceeding the accuracy requirement range), it indicates that the compensation model has failed. Recalibration should be considered, or the repeatability and stability of the pressure sensing module should be evaluated.

[0057] In summary, this invention provides a three-dimensional compensation method for absolute pressure, differential pressure, and temperature, which comprehensively considers more influencing factors and can further improve the accuracy of pressure sensing modules, especially the differential pressure measurement accuracy at low indicated air velocity, enabling applications in more fields. The three-dimensional compensation scheme based on absolute pressure, differential pressure, and temperature is simple, practical, easy to implement, effective, and highly feasible.

[0058] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0059] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A three-dimensional compensation method for absolute pressure, differential pressure, and temperature, characterized in that, The three-dimensional compensation method for absolute pressure, differential pressure, and temperature includes: Set multiple absolute pressure test pressure points, multiple differential pressure test pressure points, and multiple test temperature points; During the calibration test, the pressure sensing module is placed in a temperature chamber. The absolute pressure air path and differential pressure air path of the pressure sensing module are connected to the absolute pressure control channel and differential pressure control channel of the standard pressure controller, respectively. The differential pressure control channel uses the pressure of the absolute pressure control channel as a reference. The temperature chamber is controlled to reach the first set test temperature point, and the temperature is kept at the first test temperature point until the internal temperature of the pressure sensing module reaches the set temperature point and stabilizes. After the holding time is reached, the pressure sensing module is pressure tested. The standard pressure controller is controlled to reach each absolute pressure test pressure point, and all differential pressure test pressure points are tested and data is collected at each absolute pressure test pressure point. The temperature chamber is controlled to reach the second set test temperature point, and the above steps are repeated until the data test at all absolute pressure test pressure points and differential pressure test pressure points at each test temperature point is completed. Absolute pressure and temperature data from the absolute pressure sensor, and differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor are collected. Based on the absolute pressure and temperature data from the absolute pressure sensor and the differential pressure, temperature, and absolute pressure reference data from the differential pressure sensor, surface fitting modeling is performed, and the fitted absolute pressure calculation model and the fitted differential pressure calculation model are obtained. The pressure sensing module measures different absolute pressure, differential pressure, and temperature data in real time. Substituting the real-time measured absolute pressure and temperature data into the fitted absolute pressure calculation model yields compensated absolute pressure test data, and substituting the real-time measured absolute pressure, differential pressure, and temperature data into the fitted differential pressure calculation model yields compensated differential pressure test data, thus completing three-dimensional compensation of absolute pressure, differential pressure, and temperature.

2. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 1, characterized in that, The pressure sensor module is kept at the first test temperature point until its internal temperature reaches and stabilizes at the set temperature. After the holding time is reached, a pressure test is performed on the pressure sensor module. The standard pressure controller is controlled to reach each absolute pressure test point. The test and data acquisition for all differential pressure test points are carried out at each absolute pressure test point. The pressure sensor module is kept at the first test temperature point until the internal temperature reaches the set temperature point and stabilizes. After the holding time is reached, a pressure test is performed on the pressure sensor module. The standard pressure controller is controlled to reach the first absolute pressure test pressure point. At the first absolute pressure test pressure point, the standard pressure controller is then controlled to reach the first differential pressure test pressure point, and real-time data from the absolute pressure sensor and the differential pressure sensor are collected. The standard pressure controller is then controlled to reach the second differential pressure test pressure point, and real-time data from the absolute pressure sensor and the differential pressure sensor are collected again. The above steps are repeated to sequentially control the standard pressure controller to reach the third differential pressure test pressure point, the fourth differential pressure test pressure point, and so on. At the Nth differential pressure test pressure point, acquire the real-time data of the absolute pressure sensor and the differential pressure sensor at all differential pressure test pressure points under the first absolute pressure test pressure point; The standard pressure controller is controlled to reach the second absolute pressure test pressure point. At the second absolute pressure test pressure point, the standard pressure controller is then controlled to reach the first differential pressure test pressure point, and real-time data from the absolute pressure sensor and the differential pressure sensor are collected. The standard pressure controller is then controlled to reach the second differential pressure test pressure point, and real-time data from the absolute pressure sensor and the differential pressure sensor are collected again. The above steps are repeated to sequentially control the standard pressure controller to reach the third differential pressure test pressure point, the fourth differential pressure test pressure point, and so on. At the Nth differential pressure test pressure point, acquire the real-time data of the absolute pressure sensor and the differential pressure sensor at all differential pressure test pressure points under the second absolute pressure test pressure point; Repeat the above steps, sequentially controlling the standard pressure controller to reach the third absolute pressure test pressure point, the fourth absolute pressure test pressure point, and so on. The Mth absolute pressure test point is used to complete the testing and data acquisition of all differential pressure test points under each absolute pressure test point.

3. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 1, characterized in that, The fitted absolute pressure calculation model is as follows , where P 绝压 p is the absolute pressure fitted value. 绝压 The absolute pressure measurement value is t. 绝压 This is the absolute pressure temperature measurement value. These are the parameters for absolute pressure fitting. The absolute pressure fitting order is given by [the order of the fitting]. This represents the order of the absolute pressure temperature fitting.

4. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 3, characterized in that, The absolute pressure fitting order is 5, and the absolute pressure temperature fitting order is 6.

5. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 4, characterized in that, The fitted differential pressure calculation model is as follows ,in, These are the fitted values ​​for differential pressure. This is a differential pressure measurement value. This is a differential pressure temperature measurement value. This is the absolute pressure reference measurement value. These are the parameters for differential pressure fitting. The order of differential pressure fitting is given. The order of the differential pressure-temperature fitting is given. This represents the fitting order to the absolute pressure reference.

6. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 5, characterized in that, The differential pressure fitting order is 5, the differential pressure temperature fitting order is 6, and the absolute pressure reference order is 4.

7. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 1, characterized in that, The absolute pressure sensor is set to test pressure points of 5 kPa, 10 kPa, 20 kPa, 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, 90 kPa, and 100 kPa. The differential pressure sensor is set to test pressure points of 0 kPa, 0.5 kPa, 1 kPa, 1.5 kPa, 2 kPa, 2.5 kPa, 3 kPa, 3.5 kPa, 4 kPa, 4.5 kPa, and 5 kPa. The test temperature points are -55℃, -35℃, -15℃, 5℃, 25℃, 45℃, 65℃, and 85℃.

8. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 7, characterized in that, The differential pressure control channel, based on the pressure of the absolute pressure control channel, specifically includes: the positive pressure end of the differential pressure sensor is connected to the differential pressure control channel of the standard pressure controller, and the negative pressure end of the differential pressure sensor is connected to the absolute pressure control channel of the standard pressure controller.

9. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 1, characterized in that, The pressure sensing module is a silicon piezoresistive pressure sensor with integrated temperature sensor components.

10. The three-dimensional compensation method for absolute pressure, differential pressure, and temperature according to claim 9, characterized in that, Based on the absolute pressure and temperature data of the absolute pressure sensor, as well as the differential pressure, temperature, and absolute pressure reference data of the differential pressure sensor, a surface fitting model was performed using MATLAB.

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