CN115165208A - A sensor calibration system and method - Google Patents

Abstract

The invention belongs to the technical field of sensor calibration, and provides a sensor calibration system and method, comprising: a circuit power supply module, a single-chip microcomputer module, a sensor module, a pre-amplifier module, an analog quantity acquisition module, a host computer module, an analog quantity output module and a digital quantity Output module; the sensor module is used to convert the pressure signal into a voltage signal; the preamplifier module is used to amplify the voltage signal; the analog acquisition module is used to convert the received voltage signal into a digital signal through an analog-to-digital converter; the microcontroller module It is used to process the digital signal and transmit it to the host computer module, analog output module and digital output module respectively; the host computer module is used to communicate with the single-chip module through the standard ModBus_RTU protocol; the analog output module is connected to the digital output module. The output module is used to output the data calculated by the microcontroller module to the outside. The invention can improve the calibration efficiency of the sensor, and the linear compensation effect is good.

Description

A sensor calibration system and method

technical field

The invention belongs to the technical field of sensor calibration, and in particular relates to a sensor calibration system and method.

Background technique

At present, most of the piezoresistive sensor calibrations use a specific conditioning chip for calibration, but not all piezoresistive sensors are suitable for this calibration method. There are limited pressure points at the calibration point for calibration using the conditioning chip, and it cannot be refined after calibration. Some conditioning chips still have the problem that the calibration algorithm is fixed, and the calibration algorithm cannot be modified according to the actual application.

In the existing technical solutions, in the linear compensation of the sensor, the linear interpolation method and the polynomial curve fitting method are commonly used, and both methods have their own shortcomings. Point compensation can only achieve equal compensation. In the polynomial curve fitting method, with the increase of the number of compensation points, the amount of calculation will become larger and larger, and the phenomenon of over-fitting will occur, and the calibration effect will be poor.

SUMMARY OF THE INVENTION

The embodiments of the present invention provide a sensor calibration system and method, which can improve the calibration efficiency of the sensor and have a good compensation effect.

In a first aspect, an embodiment of the present invention provides a sensor calibration system, including: a circuit power supply module, a single-chip microcomputer module, a sensor module, a pre-amplifier module, an analog quantity acquisition module, a host computer module, an analog quantity output module, and a digital quantity output module ;

The circuit power supply module is used for supplying power to the circuit;

The sensor module is used to convert the pressure signal into a voltage signal, and transmit the voltage signal to the pre-amplification module;

The pre-amplifier module is used to amplify the voltage signal and transmit it to the analog quantity acquisition module;

The analog quantity acquisition module is used to convert the received voltage signal into a digital signal through an analog-to-digital converter, and transmit the digital signal to the single-chip microcomputer module;

The single-chip microcomputer module is used to process the digital signal and transmit it to the upper computer module, the analog output module and the digital output module respectively;

The host computer module is used to communicate and connect with the single-chip microcomputer module through the standard ModBus_RTU protocol;

The analog output module and the digital output module are used for externally outputting the data calculated by the single-chip microcomputer module.

Further, the circuit power supply module includes a voltage regulator and a step-down circuit.

Further, the step-down circuit includes: a voltage regulator chip, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, and the first capacitor and the second capacitor are connected to the first capacitor of the voltage regulator chip. one end, the first capacitor and the second capacitor are arranged in parallel, the third capacitor and the fourth capacitor are connected to the second end of the voltage regulator chip, the third capacitor and the fourth capacitor Capacitors are set in parallel.

Further, the model of the single-chip microcomputer module is STM32G030F6P6 chip.

Further, the pre-amplification module includes: a pre-amplifier chip, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, a tenth capacitor, A first resistor, a second resistor and a third resistor, the fifth capacitor is connected in parallel with the second resistor and then connected to the first end of the first resistor, and the sixth capacitor is connected in parallel with the third resistor connected to the second end of the first resistor, and one end of the seventh capacitor, the eighth capacitor, the ninth capacitor and the tenth capacitor is grounded.

Further, the analog quantity acquisition module includes: an AD conversion chip with a PGA module, a plurality of resistors connected to one end of the AD conversion chip, and a capacitor connected to the other end of the AD conversion chip.

Further, the model of the digital output module is DAC5571.

In a second aspect, an embodiment of the present invention further provides a sensor calibration method, the method includes the following steps:

Algorithm initialization: By reading the calibration parameters in the MCU Flash, the pressure percentage of the calibration point, the normalized value corresponding to the calibration pressure point, the number of calibration points and other data are read out, and then the parameters corresponding to different polyline segments are calculated. Slope and intercept, get the function expression;

Collect voltage value: control ADC to collect current voltage value and perform corresponding filtering processing through the single chip microcomputer;

Calculate the normalized value: convert the collected voltage value into the normalized value corresponding to the ADC;

Calculate the pressure percentage: find the polyline segment corresponding to the pressure normalization value according to the calculated pressure normalization value, and calculate the pressure percentage according to the functional expression of the polyline segment;

Output the required signal: According to the preset hardware, the calculated pressure percentage, and output the signal.

Further, the method also includes the calibration of the host computer module, including the steps:

Select the corresponding serial port and open it;

Select the sensor parameters and write them;

calibrate the DAC;

Input the selected pressure percentage value into the corresponding position;

Press the sensor to the pressure point corresponding to the pressure percentage, and click the corresponding button next to it to complete the data collection;

After collecting all pressure points, click the calibration button, and it will prompt that the calibration is completed, which means the calibration is successful;

Click the retest button to retest.

The beneficial effects achieved by the present invention: the present invention provides a sensor calibration system and method, and the circuit power supply module is used to supply power to the circuit, so as to provide stable voltage and sufficient power conveniently; the sensor module is used to convert the pressure signal into a voltage signal, and transmit the voltage signal to the pre-amplifier module; the pre-amplifier module is used to amplify the voltage signal and transmit it to the analog acquisition module; the analog acquisition module is used to receive the received signal through the analog-to-digital converter The voltage signal is converted into a digital signal, and the digital signal is transmitted to the single-chip microcomputer module; the single-chip microcomputer module is used to process the digital signal and transmit it to the upper computer module, the analog output module and the digital output module respectively; the upper computer module is used for Through the standard ModBus_RTU protocol to communicate with the single-chip module; the analog output module and the digital output module are used to output the data calculated by the single-chip module; the overall anti-interference ability of the system is strong, and the linear compensation effect of the sensor is good. widely.

Description of drawings

1 is a block diagram of a sensor calibration system provided by an embodiment of the present invention;

2 is a circuit diagram of a step-down circuit of a circuit power supply module provided by an embodiment of the present invention;

3 is a circuit diagram of a single-chip microcomputer module provided by an embodiment of the present invention;

4 is a circuit diagram of a pre-amplifier module provided by an embodiment of the present invention;

5 is a circuit diagram of an analog quantity acquisition module provided by an embodiment of the present invention;

6 is a circuit diagram of an analog ground and a digital ground isolation provided by an embodiment of the present invention;

FIG. 7 is a method flowchart of a sensor calibration method provided by an embodiment of the present invention.

Among them, 10, circuit power supply module, 20, microcontroller module, 30, sensor module, 40, preamplifier module, 50, analog acquisition module, 60, host computer module, 70, analog output module, 80, digital output module.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

In the linear compensation of the sensor in the prior art solutions, the linear interpolation method and the polynomial curve fitting method are commonly used. Both methods have their own shortcomings. Most of the current sensor linear compensation systems in the linear interpolation method cannot achieve point selection. Compensation can only be done equally. In the polynomial curve fitting method, with the increase of the number of compensation points, the amount of calculation will become larger and larger, and the phenomenon of over-fitting will occur, and the calibration effect will be poor. In this application, the circuit power module is used to supply power to the circuit, which is convenient to provide stable voltage and sufficient power; the sensor module is used to convert the pressure signal into a voltage signal, and transmit the voltage signal to the preamplifier module; The amplifying module is used to amplify the voltage signal and transmit it to the analog acquisition module; the analog acquisition module is used to convert the received voltage signal into a digital signal through an analog-to-digital converter, and transmit the digital signal to the single-chip microcomputer module. ; The single chip microcomputer module is used to process the digital signal and transmit it to the upper computer module, the analog output module and the digital output module respectively; the upper computer module is used to communicate with the single chip computer module through the standard ModBus_RTU protocol; the analog output module With the digital output module, it is used to output the data calculated by the single-chip microcomputer module to the outside; the overall system has strong anti-interference ability, good linear compensation effect on the sensor, and is widely used.

Example 1

Referring to Figures 1-6, Figure 1 is a block diagram of a sensor calibration system provided by an embodiment of the present invention; Figure 2 is a circuit diagram of a step-down circuit of a circuit power module provided by an embodiment of the present invention; Figure 3 is a circuit diagram of the present invention The circuit diagram of the single-chip microcomputer module provided by the embodiment; FIG. 4 is the circuit diagram of the pre-amplifier module provided by the embodiment of the present invention; FIG. 5 is the circuit diagram of the analog quantity acquisition module provided by the embodiment of the present invention; FIG. 6 is provided by the embodiment of the present invention. Circuit diagram with analog ground isolated from digital ground. A sensor calibration system 100 is provided, including: a circuit power supply module 10, a single-chip microcomputer module 20, a sensor module 30, a pre-amplifier module 40, an analog quantity acquisition module 50, a host computer module 60, an analog quantity output module 70 and a digital quantity The output module 80; the circuit power module 10 is used to supply power to the circuit, so as to provide stable voltage and sufficient power; the sensor module 30 is used to convert the pressure signal into a voltage signal, and transmit the voltage signal to the on the pre-amplifier module 40; the pre-amplifier module 40 is used to amplify the voltage signal and transmit it to the analog quantity acquisition module 50; the analog quantity acquisition module 50 is used for The converter converts the received voltage signal into a digital signal, and transmits the digital signal to the single-chip module 20; the single-chip module 20 is used to process the digital signal and transmit it to the upper position respectively On the computer module 60, the analog output module 70 and the digital output module 80; the host computer module 60 is used to communicate with the single-chip module 20 through the standard ModBus_RTU protocol; the analog output module 70 and the digital quantity output module 80 are used for externally outputting the data calculated by the single chip microcomputer module 20 . The input power is regulated and processed by the circuit power supply module 10, which is convenient for the microcontroller module 20, the sensor module 30, the pre-amplifier module 40, the analog acquisition module 50, the host computer module 60, the analog output module 70 and the digital The quantity output module 80 supplies power. The sensor voltage signal collected from the pre-amplifier module 40 is converted into a digital signal through the analog acquisition module 50 using a high-precision ADC, and the single-chip module 20 is responsible for data reception, operation, access, output and peripherals. The configuration is performed on the upper computer module 60, the analog output module 70 and the digital output module. Human-computer interaction is performed through the host computer module 60, and communication with the single-chip microcomputer module 20 is performed through the standard ModBus_RTU protocol. The data calculated by the single-chip microcomputer is output externally through the analog and digital output. The sensor has good effect of downward replenishment, high precision and wide adaptability.

More specifically, the circuit power module 10 includes a voltage regulator and a step-down circuit. The low-cost GM6155-3.3ST25R is used for the circuit power module 10 through the step-down circuit, which is responsible for converting the 5V voltage to a 3.3V voltage. A suitable power module can provide stable voltage and sufficient power for the entire circuit, with good step-down effect and safety. high.

Specifically, the step-down circuit includes: a voltage regulator chip A1, a first capacitor C1, a second capacitor C2, a third capacitor C3 and a fourth capacitor C4, the first capacitor C1 and the second capacitor C2 are connected at At the first end (pins 1, 2, 3) of the voltage regulator chip, the first capacitor C1 and the second capacitor C2 are arranged in parallel, and the third capacitor C3 and the fourth capacitor C4 are connected to each other. At the second end (pin 5) of the voltage regulator chip, the third capacitor C3 and the fourth capacitor C4 are arranged in parallel. It can be charged through the setting of the capacitor. When the circuit is unstable, the capacitor can be discharged to ensure the normal operation of the circuit. The low-cost voltage regulator chip GM6155-3.3ST25R is used for the circuit power supply module 10 through the step-down circuit, which is responsible for converting the 5V voltage to a 3.3V voltage. A suitable power module can provide stable voltage and sufficient power for the entire circuit, and the effect of step-down is good. , high security.

More specifically, the model of the single-chip microcomputer module 20 is an STM32G030F6P6 chip. The microcontroller module 20 is respectively connected to VCC and DGND. STM32G030F6P6 is used in the 20 part of the single-chip microcomputer module used. This chip has a small package, and the internal resources fully meet the requirements of this circuit. It has two serial ports, 128K-FLASH, DMA and other functions. In this circuit, one serial port, one DAM channel, The internal Flash (universal flash memory interface) and several IO ports fully utilize the functions of the interface. At the same time, the single-chip microcomputer can control the entire circuit and compensate the sensor, control the magnification of the front stage, the acquisition rate and the output mode, etc., and perform calculations internally, and use the linear interpolation method to compensate for the linearity of the sensor.

More specifically, the pre-amplifier module 40 includes: a pre-amplifier chip A5, a fifth capacitor C10, a sixth capacitor C12, a seventh capacitor C13, an eighth capacitor C14, The ninth capacitor C15, the tenth capacitor C11, the first resistor R12, the second resistor R11 and the third resistor R13, the fifth capacitor C10 and the second resistor R11 are connected in parallel with the first resistor R11. terminal, the sixth capacitor C12 is connected in parallel with the third resistor R13 and then connected to the second terminal of the first resistor R11, the seventh capacitor C13, the eighth capacitor C14, the ninth capacitor C15 and the tenth capacitor C11 one end is grounded. The circuit composed of the pre-amplifier chip, the capacitor and the resistor can have the effect of amplifying the signal, which is convenient for the single-chip microcomputer to process the received signal.

Among them, the model of the pre-amplifier chip A5 is OPA2378 operational amplifier. Using OPA2378 as the pre-amplifier can reduce the requirements for the sensitivity of the sensor. In the case of low sensitivity, this circuit can also be used for calibration, and the calibration effect is good.

The values of the fifth capacitor C10 and the sixth capacitor C12 are 10pF, the values of the seventh capacitor C13 and the eighth capacitor C14 are both 0.01uF, and the values of the ninth capacitor C15 and the tenth capacitor C11 are 0.1uF. The resistance value of the first resistor R12 is 10K ohm, and the second resistor R11 and the third resistor R13 are both 25K ohm.

More specifically, the analog quantity acquisition module 50 includes: an AD conversion chip A4 with a PGA module, a plurality of resistors (R6-R12) connected to one end of the AD conversion chip A4, and a plurality of resistors (R6-R12) connected to the AD conversion chip A4. Capacitor C10 at the other end of chip A4. ADS1247 is used for ADC acquisition. ADS1247 is a 24-bit AD conversion chip with PGA module. The PGA module can set the magnification by software, and can adjust the magnification of the entire acquisition part without changing the hardware.

More specifically, the model of the analog output module 70 may be H2U-2416MR, H2U-2416MT, and so on. It is convenient for analog output.

More specifically, the model of the digital output module 80 is DAC5571.

More specifically, the digital output module 80 (DAC output module) includes: U1, a capacitor C5 and a capacitor C6, the capacitor C5 is connected to both ends of U1, one end of the capacitor C5 is connected to the power supply, and the other end is grounded. One end of capacitor C6 is connected to pins 3 and 4 of U1, and the other end is connected to ground.

Specifically, the digital output module 80 has the advantages of simple use and high output precision, communicates with the single-chip microcomputer through a common IIC interface, and converts the circuit in the middle to match the level. This circuit can also use the remaining IO ports of the microcontroller to expand to meet the analog output. There is a module of analog quantity and digital quantity in the circuit. By connecting two 0 ohm circuits to the ground, filtering can be realized and mutual interference can be reduced.

In specific implementation, the power supply module 10 of this circuit is designed with a low-cost GM6155-3.3ST25R power supply module to convert the 5V voltage to a 3.3V voltage. A suitable power supply module can provide stable voltage and sufficient power for the entire circuit. Using OPA2378 as the pre-amplifier can reduce the requirements for the sensitivity of the sensor. In the case of low sensitivity, this circuit can also be used for calibration. The analog acquisition module 50ADC uses ADS1247 for acquisition. ADS1247 is a 24-bit AD conversion chip with a PGA module , the PGA module can set the magnification by software, and can adjust the magnification of the entire acquisition part without changing the hardware.

The microcontroller part uses STM32G030F6P6. This chip has a small package and internal resources fully meet the requirements of this circuit. It has two serial ports, 128K-FLASH, DMA and other functions. In this circuit, one serial port, one DAM channel, internal Flash and several IOs are used. mouth, the function is fully used.

The single-chip microcomputer can control the entire circuit and compensate the sensor, control the magnification of the front stage, the acquisition rate and the output mode, etc., perform calculations internally, and use the linear interpolation method to compensate the linearity of the sensor.

The DAC module uses DAC5571. This module has the advantages of simple use and high output precision. It communicates with the microcontroller through the commonly used IIC interface. This circuit can also use the remaining IO ports of the microcontroller to expand to meet the analog output. There is a module of analog quantity and digital quantity in the circuit. By connecting two 0 ohm circuits to the ground, filtering can be realized and mutual interference can be reduced.

Embodiment 2

Referring to FIG. 7 , FIG. 7 is a method flowchart of a sensor calibration method provided by an embodiment of the present invention. The embodiment of the present invention also provides a sensor calibration method, the method includes the following steps:

S01. Algorithm initialization: By reading the calibration parameters in the MCU Flash, the pressure percentage of the calibration point, the normalized value corresponding to the calibration pressure point, the number of calibration points and other data are read out, and then these parameters are used to calculate different polyline segments The corresponding slope and intercept, the function expression is obtained.

S02. Collect voltage value: control the ADC to collect the current voltage value through the single chip microcomputer and perform corresponding filtering processing.

S03. Calculate the normalized value: convert the collected voltage value into a normalized value corresponding to the ADC.

S04. Calculate the pressure percentage: find the polyline segment corresponding to the pressure normalization value according to the calculated pressure normalization value, and calculate the pressure percentage according to the functional expression of the polyline segment.

S05. Output the required signal: according to the preset hardware, the calculated pressure percentage, and output the signal.

Specifically, the compensation method uses non-uniform pressure point compensation. At the same time, the percentage of the points to be calibrated can be input in the host computer software. The advantage of this is that selective compensation can be achieved. If the linearity of the low pressure section is not good, it can be compensated in a targeted manner, and several more calibration points can be set in the low pressure section. Compensation points are supported up to 11 points and at least 2 points, so the design can meet basically all applications. The algorithm initialization process is mainly to read the parameters related to the calibration in the Flash of the microcontroller, read out the pressure percentage of the calibration point, the normalized value corresponding to the calibration pressure point, the number of calibration points, etc., and then use these parameters to calculate the different polyline segments The corresponding slope and intercept, the function expression is obtained. The microcontroller controls the ADC to collect the current voltage value and perform corresponding filtering processing; convert the collected voltage value into the normalized value corresponding to the ADC; find the line segment corresponding to the pressure normalized value according to the calculated pressure normalized value , the pressure percentage is calculated according to the function expression in this section. According to the pre-designed hardware and the calculated pressure percentage, the signal is output.

More specifically, the method also includes calibration of the host computer module, including the steps:

Step 1: Select the corresponding serial port and open it.

Step 2: Select the sensor parameters and write them.

Step 3: Calibrate the DAC.

Step 4: Enter the selected pressure percentage value into the corresponding position.

Step 5: Press the sensor to the pressure point corresponding to the pressure percentage, and click the corresponding button next to it to complete the data collection.

Step 6: After collecting all the pressure points, click the calibration button, and it will prompt that the calibration is completed, which means the calibration is successful.

Step 7: Click the retest button to retest.

Specifically, select the corresponding serial port and open it. Select the sensor parameters and write them. Calibrate the DAC.

Enter the selected pressure percentage value into the corresponding position. Press the sensor to the pressure point corresponding to the pressure percentage, and click the corresponding button next to it to complete the data collection. After collecting all the pressure points, click the calibration button, and it will prompt that the calibration is completed, which means the calibration is successful. Click the retest button to retest. The number of compensation points can be selected from 2 to 11 points. At present, most sensor linear compensation systems on the market cannot do this. The entire multi-point compensation system can meet the compensation needs of most sensors, and can choose to output various signals such as analog quantity and digital quantity. The calibration point does not need to be divided and the percentage of the pressure value of the calibration point can be input by using the host computer software. Most of the compensations on the market currently need to be divided into compensation, and the percentage value of the compensation point cannot be input. The entire compensation system is simple to use, just connect the sensor, select the corresponding output, and use it after calibration. The whole circuit is designed for industrial use environment and has strong anti-interference ability.

It should be noted that the terms "comprising" and "having" in the description and claims of the present application and the description of the drawings and any modifications thereof are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the description and claims of the present application or the drawings are used to distinguish different objects, rather than to describe a specific order. Reference herein to an "embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor a separate or alternative embodiment that is mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

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

Claims (9)

1. a sensor calibration system, is characterized in that, comprises: circuit power supply module, single chip module, sensor module, pre-amplifier module, analog quantity acquisition module, host computer module, analog quantity output module and digital quantity output module; The circuit power supply module is used for supplying power to the circuit; The sensor module is used to convert the pressure signal into a voltage signal, and transmit the voltage signal to the pre-amplification module; The pre-amplifier module is used to amplify the voltage signal and transmit it to the analog quantity acquisition module; The analog quantity acquisition module is used to convert the received voltage signal into a digital signal through an analog-to-digital converter, and transmit the digital signal to the single-chip microcomputer module; The single-chip microcomputer module is used to process the digital signal and transmit it to the upper computer module, the analog output module and the digital output module respectively; The host computer module is used to communicate and connect with the single-chip microcomputer module through the standard ModBus_RTU protocol; The analog output module and the digital output module are used for externally outputting the data calculated by the single-chip microcomputer module. 2. The sensor calibration system of claim 1, wherein the circuit power supply module comprises a voltage regulator and a step-down circuit. 3. The sensor calibration system according to claim 2, wherein the step-down circuit comprises: a voltage regulator chip, a first capacitor, a second capacitor, a third capacitor and a fourth capacitor, the first capacitor and The second capacitor is connected to the first end of the voltage regulator chip, the first capacitor and the second capacitor are arranged in parallel, and the third capacitor and the fourth capacitor are connected to the voltage regulator chip. At the second end, the third capacitor and the fourth capacitor are arranged in parallel. 4. The sensor calibration system according to claim 1, wherein the model of the single-chip microcomputer module is an STM32G030F6P6 chip. 5 . The sensor calibration system according to claim 1 , wherein the pre-amplification module comprises: a pre-amplifier chip, a fifth capacitor, a sixth capacitor, a seventh capacitor connected to the pre-amplifier chip, respectively. 6 . capacitor, eighth capacitor, ninth capacitor, tenth capacitor, first resistor, second resistor and third resistor, the fifth capacitor is connected in parallel with the second resistor and then connected to the first end of the first resistor , the sixth capacitor is connected to the second end of the first resistor after being connected in parallel with the third resistor, the seventh capacitor, the eighth capacitor, the ninth capacitor and the tenth capacitor are One end is grounded. 6. The sensor calibration system according to claim 1, wherein the analog quantity acquisition module comprises: an AD conversion chip with a PGA module, a plurality of resistors connected to one end of the AD conversion chip, and a capacitor at the other end of the AD conversion chip. 7. The sensor calibration system according to claim 1, wherein the model of the digital output module is DAC5571. 8. A calibration method for the sensor calibration system according to any one of claims 1-7, wherein the method comprises the following steps: Algorithm initialization: By reading the calibration parameters in the MCU Flash, the pressure percentage of the calibration point, the normalized value corresponding to the calibration pressure point, the number of calibration points and other data are read out, and then the parameters corresponding to different polyline segments are calculated. Slope and intercept, get the function expression; Collect voltage value: control ADC to collect current voltage value and perform corresponding filtering processing through the single chip microcomputer; Calculate the normalized value: convert the collected voltage value into the normalized value corresponding to the ADC; Calculate the pressure percentage: find the polyline segment corresponding to the pressure normalization value according to the calculated pressure normalization value, and calculate the pressure percentage according to the functional expression of the polyline segment; Output the required signal: According to the preset hardware, the calculated pressure percentage, and output the signal. 9. The sensor calibration method according to claim 8, wherein the method further comprises the calibration of the host computer module, comprising the steps of: Select the corresponding serial port and open it; Select the sensor parameters and write them; calibrate the DAC; Input the selected pressure percentage value into the corresponding position; Press the sensor to the pressure point corresponding to the pressure percentage, and click the corresponding button next to it to complete the data collection; After collecting all pressure points, click the calibration button, and it will prompt that the calibration is completed, which means the calibration is successful; Click the retest button to retest.

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