Pressure sensor calibration method and apparatus accounting for vi conversion and supply voltage error

Abstract

The application provides a pressure sensor calibration method and device considering VI conversion and power supply voltage error, relates to the technical field of sensors, and comprises the following steps: S1, constructing a calibration model representing the conversion relationship between a voltage signal and a current signal by considering power supply voltage error and VI conversion error, and simplifying the calibration model to obtain a simplified calibration model; S2, performing parameter identification on the simplified calibration model, and solving the corresponding calibrated output voltage percentage according to the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures; and S3, configuring each theoretical pressure and the corresponding calibrated output voltage percentage in a pressure sensor, thereby completing the calibration of the pressure sensor. The beneficial effect is that the product performance with very good accuracy can be obtained, and the method has the advantages of comprehensiveness, low cost, good performance and convenience.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and in particular to a method and apparatus for calibrating a pressure sensor that takes into account VI conversion and power supply voltage error. Background Technology

[0002] Industrial current-type pressure sensors commonly use a 4-20mA current output interface and typically include a sensitive pressure head, an ASIC chip and its hardware PCB, and an output connector. The ASIC chip and its hardware PCB convert industrial hydraulic and other physical quantities into voltage or current signals, which are then processed and output to the customer. There are many types of ASIC chips on the market, including those that directly convert pressure signals to current signals, and those that first convert pressure signals to voltage signals and then convert the voltage signals back to current signals via a VI (VI converter).

[0003] Current-output ASICs can directly convert pressure signals into current signals, typically supporting 4–20mA current output calibration. However, current-output ASICs require the placement of power transistors to convert current, and generally also integrate high-voltage to low-voltage conversion modules. Due to the high integration of these modules, the ASIC and its surrounding hardware generate heat. Since the ASIC is usually located close to the sensitive pressure head, which is greatly affected by temperature, this results in significant temperature drift in the sensor. The heat generation problem is usually mitigated by high-power transistors or structural improvements, but this increases cost and structural complexity.

[0004] In addition, current-type pressure sensors also require dual-channel current output. Dual-channel current output ASICs are extremely rare on the market, and using two ASICs would significantly increase costs. Therefore, using a single voltage-output ASIC to first convert the pressure signal into a voltage signal, and then converting it into a current output via dual-channel VI, is currently the common choice for dual-channel current output pressure sensors. Voltage-output ASICs generally support 0-5V voltage output calibration (using the three-point calibration principle, i.e., 3P calibration). The additional VI conversion circuit is to achieve the required 4-20mA current output. However, the current VI conversion part needs to be designed custom-. VI conversion solutions are mature and low-cost, but their accuracy is poor, and they cannot be calibrated using an ASIC. Furthermore, voltage-output ASICs use a low-voltage power supply method, which avoids the heat generation problem caused by high-voltage to low-voltage conversion, but the high-voltage to low-voltage module has low accuracy. Some ASICs even have a proportional output relationship with the supply voltage, meaning they cannot calibrate the supply voltage itself, only the output percentage. If there is an error between the supply voltage and the calibration voltage, it will seriously affect the output results, resulting in poor accuracy and easily causing the specifications to fail to meet requirements. Summary of the Invention

[0005] To address the problems existing in the prior art, this invention provides a pressure sensor calibration method that considers VI conversion and power supply voltage error, comprising:

[0006] Step S1: Considering the supply voltage error and VI conversion error, construct a calibration model characterizing the conversion relationship between voltage signal and current signal, and simplify it to obtain a simplified calibration model;

[0007] Step S2: Parameter identification is performed on the simplified calibration model, and the corresponding calibrated output voltage percentage is obtained by solving the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures.

[0008] Step S3: Configure each theoretical pressure and its corresponding calibrated output voltage percentage in the pressure sensor to complete the calibration of the pressure sensor.

[0009] Preferably, before performing step S1, the voltage signal is further calibrated using a 3P calibration method.

[0010] Preferably, the expression for the calibration model is as follows:

[0011] I out =V in *(1+p)*(a2Vout 2 +b2Vout+c2)

[0012] Among them, I out V represents the current output quantity corresponding to the current signal. in V is the theoretical supply voltage, p is the supply voltage error, and V out denoted as the percentage of the output voltage corresponding to the voltage signal, and a2, b2, and c2 are the coefficients of the quadratic function.

[0013] Preferably, to simultaneously consider the calibration of supply voltage error and VI conversion error, the simplified calibration model expression is as follows:

[0014]

[0015] a = 5V * (1 + p) * a²

[0016] b = 5V * (1 + p) * b²

[0017] c = 5V * (1 + p) * c²

[0018] Where a, b, and c are the coefficients of the simplified calibration model, respectively.

[0019] Preferably, step S2 specifically includes the following steps:

[0020] S21, configure the theoretical output voltage percentage corresponding to the three theoretical pressures, and obtain the theoretical current output corresponding to each theoretical output voltage percentage;

[0021] S22, Substitute the three sets of theoretical output voltage percentages and the corresponding theoretical current outputs into the simplified calibration model, solve for the coefficients of the simplified calibration model, and complete the parameter identification of the simplified calibration model;

[0022] S23, based on the expression of the simplified calibration model after parameter identification, the corresponding percentage of the calibrated output voltage is obtained by solving for the three theoretical current output quantities respectively.

[0023] Preferably, the theoretical pressure includes zero pressure, full-scale pressure, and intermediate-scale pressure between the zero pressure and the full-scale pressure, wherein the intermediate-scale pressure is half-scale pressure.

[0024] Preferably, the pressure sensor includes a signal conversion module for converting the detected pressure signal into a voltage signal, a voltage-to-current conversion module for converting the voltage signal into a current signal, and a high-voltage conversion module for supplying power to the signal conversion module and the voltage-to-current conversion module.

[0025] This invention also provides a pressure sensor calibration device considering VI conversion and power supply voltage error, used to implement the above-described pressure sensor calibration method. The pressure sensor includes a signal conversion board disposed above a sensitive pressure head. A voltage-to-current conversion board is connected above the signal conversion board via a first electrical connector, and a high-voltage conversion board is connected above the voltage-to-current conversion board via a second electrical connector. The calibration device then includes a calibration board connected to the signal conversion board. The calibration board includes:

[0026] A construction module is used to construct a calibration model that characterizes the conversion relationship between the voltage signal and the current signal, taking into account the power supply voltage error and the VI conversion error, and then simplifying it to obtain a simplified calibration model.

[0027] The calibration module, connected to the construction module, is used to identify parameters of the simplified calibration model and solve for the corresponding calibrated output voltage percentage based on the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures.

[0028] The configuration module, connected to the calibration module, is used to configure each theoretical pressure and its corresponding calibrated output voltage percentage in the signal conversion board to complete the calibration of the current-type pressure sensor.

[0029] Preferably, it also includes an output interface connector, through which the high voltage conversion board is connected to a power test line, and then connected to an external test computer via the power test line;

[0030] The power test line provides high-voltage DC power to the current-type pressure sensor and outputs the current signal from the pressure sensor to the external test computer.

[0031] Preferably, the signal conversion board also integrates a 3P calibration program for calibrating the voltage signal using the 3P calibration method.

[0032] The above technical solution has the following advantages or beneficial effects:

[0033] To address the accuracy issues arising from the use of voltage-type signal conversion modules, low-cost voltage-to-current conversion modules, and low-precision high-voltage conversion modules in current-type pressure sensors, this paper fully utilizes the calibration function of the voltage-type signal conversion module itself. It also takes into account the errors introduced by the voltage-to-current and high-voltage conversion modules. During calibration, a calibration model that simultaneously considers VI conversion and power supply voltage errors is constructed and uniformly processed throughout the calibration process. This comprehensive and practical approach yields a product with excellent accuracy, offering advantages such as low cost, high performance, and ease of use. Attached Figure Description

[0034] Figure 1 A flowchart illustrating a pressure sensor calibration method that takes into account VI conversion and power supply voltage error is provided in a preferred embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of a sub-process of step S2 in a preferred embodiment of the present invention;

[0036] Figure 3 A schematic diagram of a pressure sensor calibration device that takes into account VI conversion and power supply voltage error is provided in a preferred embodiment of the present invention.

[0037] Figure 4 The electrical schematic diagram of the calibration board is shown in a preferred embodiment of the present invention. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. The present invention is not limited to this embodiment; other embodiments that conform to the spirit of the present invention may also fall within the scope of the present invention.

[0039] In a preferred embodiment of the present invention, based on the above-mentioned problems existing in the prior art, a calibration method for a pressure sensor considering VI conversion and power supply voltage error is provided, comprising:

[0040] Step S1: Considering the supply voltage error and VI conversion error, construct a calibration model characterizing the conversion relationship between voltage signal and current signal, and simplify it to obtain a simplified calibration model;

[0041] Step S2: Parameter identification is performed on the simplified calibration model, and the corresponding calibrated output voltage percentage is obtained by solving the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures.

[0042] Step S3: Configure each theoretical pressure and its corresponding calibrated output voltage percentage in the pressure sensor to complete the calibration of the pressure sensor.

[0043] Specifically, the aforementioned pressure sensor is a current-type pressure sensor, including a signal conversion module for converting the detected pressure signal into a voltage signal, a voltage-to-current conversion module for converting the voltage signal into a current signal, and a high-voltage conversion module for powering the signal conversion module and the voltage-to-current conversion module. For current-type products using voltage-output ASIC designs, due to the low power consumption of ASICs, minimal heat generation around the sensitive pressure head, and relatively stable performance, they are widely used. Therefore, in this embodiment, the aforementioned signal conversion module preferably uses a voltage-output ASIC chip. A VI conversion section (i.e., a voltage-to-current conversion module) is added to the voltage-output pressure sensor with an ASIC chip. Furthermore, based on voltage calibration of the ASIC chip, the VI conversion section and the high-voltage power supply section are uniformly calibrated separately to effectively eliminate errors in the VI conversion section and the high-voltage power supply section, further improving the accuracy of the current-type pressure sensor and ensuring its specifications meet the usage requirements.

[0044] In a preferred embodiment of the present invention, the converted voltage signal is further calibrated using a 3P calibration method before performing step S1.

[0045] Specifically, taking a current-type pressure sensor with a range of 0–250 bar and an output of 4–20 mA as an example, the signal conversion module uses a standard 5V power supply and adopts a 3P calibration method. The calibration relationship between the pressure signal and the voltage output percentage satisfies the following quadratic equation:

[0046]

[0047] Among them, V out It is the voltage output percentage value, P in is the pressure value input by the sensitive pressure head, and a1, b1, and c1 are the coefficients of a quadratic equation.

[0048] Furthermore, by obtaining three sets of P in and V outThe correspondence (i.e., three points) is obtained by solving a system of three linear equations in three variables, and then a1, b1, c1 are obtained. Based on the above quadratic equation, the 3P calibration of the voltage output percentage is realized. Preferably, the above 3P calibration process is integrated into the signal conversion module as a 3P calibration program, so that the signal conversion module can have a built-in 3P calibration function.

[0049] For current-type pressure sensors, since the voltage data output from the signal conversion module also needs to be converted from voltage to current, obtaining the voltage output solely through 3P calibration is insufficient; calibration is also required to address the errors introduced by the signal conversion section. The currently commonly used theoretical relationship for voltage-to-current conversion is as follows:

[0050] I out =5V*(4.8V) out )

[0051] Wherein, 4.8 is the theoretical linear scaling factor for voltage-current conversion.

[0052] Then it can be deduced that:

[0053] When I out =4mA, then V out =16.6667%=V l ;

[0054] When I out =12mA, then V out =50.0000%=V m ;

[0055] When I out =20mA, then V out =83.3333%=V h .

[0056] V l V m V h These represent the high, medium, and low percentages of the theoretical output voltage. Theoretically, by configuring the theoretical output voltage percentage for each of the three pressure points (0 bar, 125 bar, and 250 bar) on the 250 bar range, the pressure value P input to the sensitive pressure head can be obtained. in The output current value I of the current-type sensor out The relationship.

[0057] However, in practical engineering applications, on the one hand, the 5V voltage provided by the high-voltage conversion module has an error (assuming the supply voltage error is p), which affects the accuracy of the current output. On the other hand, the voltage-to-current conversion is not actually an absolute linear proportional relationship as represented by the above-mentioned theoretical relationship. Based on engineering practice and theoretical knowledge, this invention sets a quadratic term function relationship between the voltage signal output by the signal conversion module and the current signal output by the voltage-to-current conversion module. That is, the expression of the calibration model is as follows:

[0058] I out =V in *(1+p)*(a2Vout 2 +b2Vout+c2)

[0059] Among them, I out V represents the current output quantity corresponding to the current signal. in V represents the theoretical supply voltage of the high-voltage conversion module, p represents the supply voltage error, and V represents the voltage level. out Let a2, b2, and c2 be the output voltage percentage corresponding to the voltage signal, and a2, b2, and c2 be the coefficients of the quadratic function. It can be seen that when a2 is 0, a linear relationship can be represented, demonstrating that this invention considers the linear relationship, while the quadratic function relationship is closer to the actual situation.

[0060] At this point, due to the combined influence of p, a2, b2, and c2, the previously set theoretical output voltage percentage does not correspond to the theoretical output current. Furthermore, testing revealed that the accuracy of the actual output current obtained is far below the requirements of the pressure sensor. Therefore, to facilitate the solution of the calibration model, let:

[0061] a = 5V * (1 + p) * a²

[0062] b = 5V * (1 + p) * b²

[0063] c = 5V * (1 + p) * c²

[0064] Simplifying the above quadratic function relationship, we obtain a simplified calibration model, whose expression is:

[0065]

[0066] Where a, b, and c are the coefficients of the simplified calibration model. It can be seen that this simplified calibration model is also a three-variable linear equation, requiring only three sets of output current I. out and output voltage percentage V out By understanding the relationship between the coefficients a, b, and c, we can obtain their values.

[0067] Specifically, based on step S2, the above coefficients are solved to obtain the percentage of the calibrated output voltage, where, for example... Figure 2 As shown, step S2 specifically includes the following steps:

[0068] S21, configure the theoretical output voltage percentage corresponding to the three theoretical pressures, and obtain the theoretical current output corresponding to each theoretical output voltage percentage;

[0069] S22, Substitute the three sets of theoretical output voltage percentages and corresponding theoretical current outputs into the simplified calibration model, solve for the coefficients of the simplified calibration model, and complete the parameter identification of the simplified calibration model.

[0070] S23, based on the expression of the simplified calibration model after parameter identification, solve for the corresponding percentage of the calibrated output voltage when the output current is one of the three theoretical current output values.

[0071] Therefore, this invention first configures multiple theoretical output voltage percentages corresponding to theoretical pressures. In a preferred embodiment of this invention, the theoretical pressures include zero pressure, full-scale pressure, and an intermediate-scale pressure between zero pressure and full-scale pressure, where the intermediate-scale pressure is a half-scale pressure. The theoretical output voltage percentage corresponding to zero pressure is the high percentage of the output voltage, V. l The theoretical output voltage percentage corresponding to the intermediate range pressure is the high output voltage percentage V. m The theoretical output voltage percentage corresponding to full-scale pressure is the high percentage of output voltage, V. h In this embodiment, V can be set to... l =16.666%, V m =50%, V h =83.333%, then:

[0072] When the pressure value P input by the sensitive pressure head in When the voltage is 0 bar, the corresponding theoretical output voltage percentage V is configured. l =16.666%, and the current output I of the voltage-to-current conversion module was collected and recorded when only 3P calibration was performed. out_l ;

[0073] When the pressure value P input by the sensitive pressure head in =125 bar, corresponding to the theoretical output voltage percentage V m =50%, and collect and record the current output I corresponding to the voltage-to-current conversion module when only 3P calibration is performed. out_m ;

[0074] When the pressure value P input by the sensitive pressure head in =250 bar, corresponding to the theoretical output voltage percentage V h=83.333%, and the current output I corresponding to the voltage-to-current conversion module was collected and recorded when only 3P calibration was performed. out_h ;

[0075] Substitute the above three sets of data into I out =aV out 2 +b*V out In +c, solve the system of three linear equations in three variables, and we get:

[0076]

[0077]

[0078] c = I out_l -a*V l 2 -bV l

[0079] After calculating the values ​​of a, b, and c, we obtain the quadratic function relationship with fixed parameters.

[0080] Based on this relation, and performing the corresponding inverse calculation, we have:

[0081] When I out Solve the quadratic equation when the current is 4mA. make Then we can solve for V. l ′=V out = (-b±Δl) / 2a. In practical engineering, the solution (-b-Δl) / 2a often has a value greater than 1, which does not satisfy the domain of 0 to 100%. Therefore, V is chosen. l ′=V out = (-b+Δl) / 2a, where the pressure value P corresponding to the input of the sensitive pressure head during calibration is... in =0 bar;

[0082] When I out Solve the quadratic equation when the current is 12mA. make Then we can solve for V′ m =V out = (-b±Δm) / 2a, in actual engineering, the solution (-b-Δm) / 2a is often greater than 1, which does not satisfy the domain of 0 to 100%, therefore V′ m =V out = (-b+Δm) / 2a, where the pressure value P corresponding to the input of the sensitive pressure head during calibration is... in =125 bar;

[0083] When I out Solve the quadratic equation when the current is 20mA. make Then we can solve for V′ h =V out = (-b±Δh) / 2a, in actual engineering, the solution (-b-Δh) / 2a is often greater than 1, which does not satisfy the domain of 0 to 100%, therefore V′ h =V out = (-b+Δh) / 2a, where the pressure value P corresponding to the input of the sensitive pressure head during calibration is... in =250 bar.

[0084] In summary, the three theoretical current output quantities I are finally... out =4mA, 12mA, 20mA corresponds to a set of solution values ​​V l ', V m ', V h If configured as a percentage of the output voltage after calibration, then:

[0085] The pressure value P input by the sensitive pressure head in =0 bar, configured output voltage percentage V after calibration l ', thus obtaining the accurate current output I out_l ';

[0086] The pressure value input to the sensitive pressure head is Pin = 125 bar, and the output voltage percentage V is configured after calibration. m ', thus obtaining the accurate current output I out_m ';

[0087] The pressure value P input by the sensitive pressure head in =250 bar, configured output voltage percentage V after calibration h ', thus obtaining the accurate current output I out_h ';

[0088] The calibration is now complete.

[0089] In summary, this invention fully utilizes the calibration function of the voltage-type signal conversion module itself, while also taking into account the errors introduced by the voltage-current conversion module and the high-voltage conversion module. During calibration, a calibration model is constructed based on the power supply voltage error, and uniform processing is performed during the calibration process. This comprehensive and practical approach results in product performance with excellent accuracy. It also boasts advantages such as low cost, high performance, and ease of use.

[0090] In a preferred embodiment of the present invention, such as Figure 3 As shown, the current-type pressure sensor includes:

[0091] A sensitive pressure head 1 is provided, and a signal conversion board 2 is fixed above the sensitive pressure head 1. A voltage-current conversion board 4 is connected above the signal conversion board 2 via a first electrical connector 3. A high voltage conversion board 6 is connected above the voltage-current conversion board 4 via a second electrical connector 5.

[0092] The signal conversion module is integrated on the signal circuit board 2, the voltage-current conversion module is integrated on the voltage-current conversion board 4, and the high voltage conversion module is integrated on the high voltage conversion board 6.

[0093] Specifically, in this embodiment, by setting the first electrical connector 3 and the second electrical connector 4, the signal conversion board 2, the voltage-current conversion board 4 and the high-voltage conversion board 6 are isolated in the vertical space. Through reverse integration, the heat generated by the high-voltage conversion board 6 and the voltage-current conversion board 4 can be effectively prevented from affecting the output of the signal conversion board 2. In addition, the mutual electromagnetic interference between the three is also effectively reduced, and the structure is stable and no additional components need to be added.

[0094] The present invention also provides a pressure sensor calibration device that takes into account VI conversion and power supply voltage errors, for implementing the above-described pressure sensor calibration method, such as... Figure 3 As shown, the current-type pressure sensor includes a signal conversion board 2 disposed above the sensitive pressure head 1, with a signal conversion module integrated on the signal conversion board 2. A voltage-to-current conversion board 4 is connected above the signal conversion board 2 via a first electrical connector 3, with a voltage-to-current conversion module integrated on the voltage-to-current conversion board 4. A high-voltage conversion board 6 is connected above the voltage-to-current conversion board 4 via a second electrical connector 5, with a high-voltage conversion module integrated on the high-voltage conversion board 6. The calibration device includes a calibration board 7 connected to the signal conversion board 2, such as... Figure 4 As shown, calibration plate 7 includes:

[0095] Module 71 is used to construct a calibration model that characterizes the conversion relationship between voltage and current signals, taking into account supply voltage error and VI conversion error, and then simplifying it to obtain a simplified calibration model.

[0096] The calibration module 72, connected to the construction module 71, is used to identify parameters of the simplified calibration model and solve for the corresponding percentage of the output voltage after calibration based on the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures.

[0097] The configuration module 73 is connected to the calibration module 72 and is used to configure each theoretical pressure and its corresponding calibrated output voltage percentage in the signal conversion board to complete the calibration of the current-type pressure sensor.

[0098] In a preferred embodiment of the present invention, an output interface connector 8 is also included. The high voltage conversion board 6 is connected to the power test line 9 through the output interface connector 8, and then connected to an external test computer through the power test line 9.

[0099] Power test line 9 provides high-voltage DC power to the current-type pressure sensor and outputs the current signal from the current-type pressure sensor to an external test computer.

[0100] In a preferred embodiment of the present invention, the signal conversion board 2 is further integrated with a 3P calibration program for calibrating the converted voltage signal using the 3P calibration method.

[0101] Specifically, in this embodiment, the calibration steps using the calibration device are as follows:

[0102] 1) Connect one end of the power test line 9 to the output interface connector 8 of the current-type pressure sensor, and the other end to the external test computer. The power test line 9 is used to provide high voltage DC power (PIN1) to the current-type pressure sensor and to collect the output current signal (PIN2, PIN4) to the external test computer. The power supply voltage (9~32V) provides 5V working voltage to the voltage-current conversion board 4 through the first electrical connector 5 after passing through the high voltage conversion board 6 (this voltage will have an error, assuming the power supply voltage error is p).

[0103] 2) The signal conversion board 2 collects the pressure signal output by the sensitive pressure head 1 and converts it into a voltage signal. The voltage signal is then calibrated to the required voltage Vout by the 3P calibration program embedded in the signal conversion board 2. Considering the error caused by the power supply of the high voltage conversion board 6 in actual conditions, the precise 5V power supply of the calibration board is not used when powering the signal conversion board 2 during calibration. Instead, the high voltage conversion board 6 is used for power supply.

[0104] 3) The calibrated voltage is then converted into a current signal by the voltage-to-current conversion board 4, and finally the current signal is output through the output interface connector 8. During this process, the calibrated output voltage percentage obtained by inverse calculation is adjusted by the calibration board 7 to obtain an accurate current output.

[0105] 4) After calibration, the current-type pressure sensor can be packaged and shipped after disconnecting the power test line 9 and the calibration board 7.

[0106] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made using the content of this specification and illustrations should be included within the protection scope of the present invention.

Claims

1. A pressure sensor calibration method considering VI conversion and power supply voltage error, characterized in that, include: Step S1: Considering the supply voltage error and VI conversion error, construct a calibration model characterizing the conversion relationship between voltage signal and current signal, and simplify it to obtain a simplified calibration model; Step S2: Parameter identification is performed on the simplified calibration model, and the corresponding calibrated output voltage percentage is obtained by solving the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures. Step S3: Configure each theoretical pressure and its corresponding calibrated output voltage percentage in the pressure sensor to complete the calibration of the pressure sensor.

2. The pressure sensor calibration method according to claim 1, characterized in that, Before performing step S1, the voltage signal is calibrated using a 3P calibration method.

3. The pressure sensor calibration method according to claim 1, characterized in that, The expression for the calibration model is as follows: ； in, This refers to the current output quantity corresponding to the current signal. The theoretical supply voltage, The power supply voltage error, The percentage of the output voltage corresponding to the voltage signal. These are the coefficients of the quadratic function.

4. The pressure sensor calibration method according to claim 3, characterized in that, To simultaneously consider the calibration of both supply voltage error and VI conversion error, the simplified calibration model expression is as follows: ； Where a, b, and c are the coefficients of the simplified calibration model, respectively.

5. The pressure sensor calibration method according to claim 4, characterized in that, Step S2 specifically includes the following steps: S21, configure the theoretical output voltage percentage corresponding to the three theoretical pressures, and obtain the theoretical current output corresponding to each theoretical output voltage percentage; S22, Substitute the three sets of theoretical output voltage percentages and the corresponding theoretical current outputs into the simplified calibration model, solve for the coefficients of the simplified calibration model, and complete the parameter identification of the simplified calibration model; S23, based on the expression of the simplified calibration model after parameter identification, the corresponding percentage of the calibrated output voltage is obtained by solving for the three theoretical current output quantities respectively.

6. The pressure sensor calibration method according to claim 5, characterized in that, The theoretical pressure includes zero pressure, full-scale pressure, and intermediate-scale pressure between the zero pressure and the full-scale pressure, wherein the intermediate-scale pressure is half-scale pressure.

7. The pressure sensor calibration method according to claim 1, characterized in that, The pressure sensor includes a signal conversion module for converting the detected pressure signal into a voltage signal, a voltage-to-current conversion module for converting the voltage signal into a current signal, and a high-voltage conversion module for supplying power to the signal conversion module and the voltage-to-current conversion module.

8. A pressure sensor calibration device considering VI conversion and power supply voltage error, characterized in that, For implementing the pressure sensor calibration method as described in any one of claims 1-7, the pressure sensor includes a signal conversion board disposed above a sensitive pressure head, a voltage-to-current conversion board connected above the signal conversion board via a first electrical connector, and a high-voltage conversion board connected above the voltage-to-current conversion board via a second electrical connector; then the calibration device includes a calibration board connected to the signal conversion board, the calibration board comprising: A construction module is used to construct a calibration model that characterizes the conversion relationship between the voltage signal and the current signal, taking into account the supply voltage error and VI conversion error, and then simplifying it to obtain a simplified calibration model. The calibration module, connected to the construction module, is used to identify parameters of the simplified calibration model and solve for the corresponding calibrated output voltage percentage based on the simplified calibration model after parameter identification and the theoretical current output corresponding to multiple theoretical pressures. The configuration module, connected to the calibration module, is used to configure each theoretical pressure and its corresponding calibrated output voltage percentage in the signal conversion board to complete the calibration of the pressure sensor.

9. The pressure sensor calibration device according to claim 8, characterized in that, It also includes an output interface connector, through which the high voltage conversion board is connected to a power test line, and then to an external test computer via the power test line. The power test line provides high-voltage DC power to the pressure sensor and outputs the current signal from the pressure sensor to the external test computer.

10. The pressure sensor calibration device according to claim 8, characterized in that, The signal conversion board also integrates a 3P calibration program, which is used to calibrate the voltage signal using the 3P calibration method.

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