阅读说明：本技术 压力检测方法和压力检测系统 (Pressure detection method and pressure detection system ) 是由 赵寒阳 王振东 于 2021-08-26 设计创作，主要内容包括：本发明提供一种压力检测方法和压力检测系统,该方法包括实时获取压力传感器检测并输出的流体的压力值和温度传感器检测并输出的流体的温度值；将压力值和温度值转换为数字信号；利用预设的温度补偿关系式根据转换后的温度值对转换后的压力值进行温度补偿,获得温度值下的补偿压力值；将补偿压力值转换为模拟信号后输出。本发明提供的压力检测方法和压力检测系统的技术方案,利用软件对压力传感器输出的压力值进行温度补偿,无需使用硬件电路,避免了因硬件电路补偿产生的问题,从而可以提高补偿精度。(The invention provides a pressure detection method and a pressure detection system, wherein the method comprises the steps of acquiring the pressure value of fluid detected and output by a pressure sensor and the temperature value of the fluid detected and output by a temperature sensor in real time; converting the pressure value and the temperature value into digital signals; performing temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression to obtain a compensation pressure value under the temperature value; and converting the compensation pressure value into an analog signal and outputting the analog signal. According to the technical scheme of the pressure detection method and the pressure detection system, the temperature compensation is performed on the pressure value output by the pressure sensor by using software, a hardware circuit is not needed, the problem caused by hardware circuit compensation is avoided, and therefore the compensation precision can be improved.)

1. A pressure detection method, comprising:

acquiring a pressure value of a fluid detected and output by a pressure sensor and a temperature value of the fluid detected and output by a temperature sensor in real time;

converting the pressure value and the temperature value into digital signals;

performing temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression to obtain a compensation pressure value under the temperature value;

and converting the compensation pressure value into an analog signal and outputting the analog signal.

2. The pressure detection method of claim 1, wherein the temperature compensation relationship is:

wherein, U_t' is the compensated pressure value at the temperature value;

U_tis the pressure value detected by the pressure sensor at the temperature value;

a₀the pressure sensor is a zero pressure value output by the pressure sensor when the temperature of the fluid is normal temperature and the pressure value of the fluid is 0 Psig;

b₀the sensitivity value of the pressure sensor is when the temperature of the fluid is normal temperature and the pressure value of the fluid is 0 Psig;

a_t' is a zero point compensation pressure value under the temperature value obtained in advance;

b_tis obtained in advanceA sensitivity compensation value at the temperature value;

t is the temperature value.

3. The pressure detection method according to claim 2, wherein the zero-point compensation pressure value is obtained based on the temperature value and a preset zero-point pressure compensation function, and the sensitivity compensation value is obtained based on the temperature value and a preset sensitivity compensation function;

wherein the zero pressure compensation function and the sensitivity compensation function are obtained by:

selecting a plurality of set pressure values in the range of the pressure sensor, wherein the plurality of set pressure values comprise 0 Psig;

acquiring pressure groups corresponding to the plurality of set pressure values one to one, wherein each pressure group comprises pressure values output by the pressure sensors at different temperatures of the set pressure value corresponding to the pressure group, and the pressure value group corresponding to 0Psig is a zero-point pressure value group;

obtaining zero point pressure values which are not subjected to temperature compensation at different temperatures according to pressure values output by the pressure sensors at different temperatures in the zero point pressure value group;

obtaining sensitivity values which are not subjected to temperature compensation at different temperatures according to the pressure groups which are in one-to-one correspondence with the plurality of set pressure values;

fitting the zero pressure values which are not subjected to temperature compensation at different temperatures to obtain the zero pressure compensation function;

and fitting the sensitivity values of the different temperature values without temperature compensation to obtain the sensitivity compensation function.

4. The pressure detection method according to claim 3, wherein the fitting the zero-point pressure values without temperature compensation at the different temperatures to obtain the zero-point compensation pressure value function specifically includes:

and fitting the zero pressure values which are not subjected to temperature compensation at different temperatures in a curve fitting manner to obtain the zero pressure compensation function, wherein the zero pressure compensation function is a third-order polynomial as follows:

a_t'＝k₀+k₁t+k₂t²+k₃t³

wherein, a_t' is a zero point compensation pressure value under the temperature value obtained in advance; t is the temperature value; k is a radical of₀、k₁、k₂And k₃Constant term coefficients, first term coefficients, second term coefficients and third term coefficients, respectively.

5. The pressure detection method according to claim 3 or 4, wherein the zero pressure values without temperature compensation at different temperatures are obtained by using the following formula:

a_t＝a₀+α(t-t₀)×F.S.

wherein, a_tThe zero pressure value is not subjected to temperature compensation at different temperatures; alpha is a zero coefficient when the temperature of the fluid is normal temperature and the pressure of the fluid is 0 Psig; F.S. is the upper limit value of the measuring range of the pressure sensor; t is t₀And the temperature value is the temperature value corresponding to the normal temperature.

6. The method according to claim 3, wherein the fitting the sensitivity values without temperature compensation at different temperatures to obtain the sensitivity compensation function specifically comprises:

and fitting the sensitivity values which are not subjected to temperature compensation at different temperatures in a curve fitting manner to obtain the sensitivity compensation function, wherein the sensitivity compensation function is a third-order polynomial as follows:

b_t'＝s₀+s₁t+s₂t²+s₃t³

wherein, b_t' is a sensitivity compensation value at the temperature value obtained in advance; t is the temperature value; s₀、s₁、s₂And s₃Are respectively a constant term systemNumber, first order coefficient, second order coefficient, and third order coefficient.

7. The pressure detection method according to claim 3 or 6, wherein the sensitivity values without temperature compensation at different temperatures are obtained by using the following formula:

b_t＝b₀+β(t-t₀)×F.S.

wherein, b_tThe sensitivity values at the different temperatures are not subjected to temperature compensation; β is the sensitivity coefficient of the pressure sensor; t is the temperature value; t is t₀The temperature value is the temperature value corresponding to the normal temperature; and F.S. is the upper limit value of the measuring range of the pressure sensor.

8. The pressure detection method according to claim 1, wherein the converting the compensated pressure value into an analog signal and outputting the analog signal includes:

and converting the digital signal of the compensation pressure value into a current signal of 4mA-20mA and then outputting the current signal.

9. A pressure sensing system, comprising: a pressure sensor, a temperature sensor, a signal processing module, an AD conversion module, a processor and a DA conversion module, wherein,

the pressure sensor is used for detecting the pressure of the fluid in real time and outputting a pressure value;

the temperature sensor is used for detecting the temperature of the fluid in real time and outputting a temperature value;

the signal processing module is used for converting the electric signals corresponding to the pressure value and the temperature value into voltage signals;

the AD conversion module is used for converting the voltage signals corresponding to the pressure value and the temperature value into digital signals;

the processor is used for performing temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression so as to obtain a compensation pressure value under the temperature value; and

and the DA conversion module is used for converting the compensation pressure value into an analog signal and then outputting the analog signal.

10. The pressure detection system of claim 9, further comprising:

and the display module is used for receiving and displaying the compensation pressure value.

Technical Field

The invention relates to the field of semiconductor manufacturing, in particular to a pressure detection method and a pressure detection system.

Background

The information technology is based on three technologies of information acquisition, information transmission and information processing. The sensor is an electronic device or apparatus that can convert external non-electrical signals such as physical quantity, chemical quantity, and biomass into electrical signals and output them, and is the most important device for acquiring information. The pressure signal is an important parameter of an industrial control system, and the correct measurement and control of the pressure are one of the necessary conditions for ensuring the normal operation of the industrial system. The pressure sensor has the characteristics of high sensitivity, high precision, good reliability, quick dynamic response, easy miniaturization and integration, and is widely applied to various fields of aerospace, petrochemical industry, semiconductor equipment and the like to measure hydraulic pressure, air pressure and the like.

Although the pressure sensor has many advantages, there still exist some defects in practical engineering use, for example, the pressure sensor needs to be in contact with the measured object in the process of pressure measurement, and the pressure sensor is affected by the temperature change of the measured object, resulting in zero drift and sensitivity drift of its output signal. Therefore, in the prior art, a hardware circuit compensation method is adopted to reduce the influence of external parameters (such as temperature) on the measurement precision of the sensor, so that temperature compensation is realized.

However, the above-mentioned hardware circuit compensation method is complex in design and difficult to debug, and is limited by its own characteristics and temperature influence, and the hardware circuit compensation method is difficult to calibrate all sampling signals, and has poor compensation accuracy.

Disclosure of Invention

The invention aims to at least solve one of the technical problems in the prior art, and provides a pressure detection method and a pressure detection system, which utilize software to carry out temperature compensation on a pressure value detected and output by a pressure sensor, do not need to use a hardware circuit, avoid the problem caused by the compensation of the hardware circuit and further improve the compensation precision.

To achieve the object of the present invention, there is provided a pressure detecting method including:

acquiring a pressure value of a fluid detected and output by a pressure sensor and a temperature value of the fluid detected and output by a temperature sensor in real time;

converting the pressure value and the temperature value into digital signals;

performing temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression to obtain a compensation pressure value under the temperature value;

and converting the compensation pressure value into an analog signal and outputting the analog signal.

Optionally, the temperature compensation relation is as follows:

wherein, U_t' is the compensated pressure value at the temperature value;

U_tis the pressure value detected by the pressure sensor at the temperature value;

a₀the pressure sensor is a zero pressure value output by the pressure sensor when the temperature of the fluid is normal temperature and the pressure value of the fluid is 0 Psig;

b₀the sensitivity value of the pressure sensor is when the temperature of the fluid is normal temperature and the pressure value of the fluid is 0 Psig;

a_t' is a zero point compensation pressure value under the temperature value obtained in advance;

b_t' is a sensitivity compensation value at the temperature value obtained in advance;

t is the temperature value.

Optionally, the zero-point compensation pressure value is obtained based on the temperature value and a preset zero-point pressure compensation function, and the sensitivity compensation value is obtained based on the temperature value and a preset sensitivity compensation function;

wherein the zero pressure compensation function and the sensitivity compensation function are obtained by:

selecting a plurality of set pressure values in the range of the pressure sensor, wherein the plurality of set pressure values comprise 0 Psig;

acquiring pressure groups corresponding to the plurality of set pressure values one to one, wherein each pressure group comprises pressure values output by the pressure sensors at different temperatures of the set pressure value corresponding to the pressure group, and the pressure value group corresponding to 0Psig is a zero-point pressure value group;

obtaining zero point pressure values which are not subjected to temperature compensation at different temperatures according to pressure values output by the pressure sensors at different temperatures in the zero point pressure value group;

obtaining sensitivity values which are not subjected to temperature compensation at different temperatures according to the pressure groups which are in one-to-one correspondence with the plurality of set pressure values;

fitting the zero pressure values which are not subjected to temperature compensation at different temperatures to obtain the zero pressure compensation function;

and fitting the sensitivity values of the different temperature values without temperature compensation to obtain the sensitivity compensation function.

Optionally, the fitting the zero pressure values without temperature compensation at different temperatures to obtain the zero compensation pressure value function specifically includes:

and fitting the zero pressure values which are not subjected to temperature compensation at different temperatures in a curve fitting manner to obtain the zero pressure compensation function, wherein the zero pressure compensation function is a third-order polynomial as follows:

a_t'＝k₀+k₁t+k₂t²+k₃t³

wherein, a_t' is a zero point compensation pressure value under the temperature value obtained in advance; t is the temperature value; k is a radical of₀、k₁、k₂And k₃Constant term coefficients, first term coefficients, second term coefficients and third term coefficients, respectively.

Optionally, the zero pressure value without temperature compensation at different temperatures is obtained by using the following formula:

a_t＝a₀+α(t-t₀)×F.S.

wherein, a_tThe zero pressure value is not subjected to temperature compensation at different temperatures; alpha is a zero coefficient when the temperature of the fluid is normal temperature and the pressure of the fluid is 0 Psig; F.S. is the upper limit value of the measuring range of the pressure sensor; t is t₀Is corresponding to the normal temperatureA temperature value.

Optionally, the fitting the sensitivity values without temperature compensation at different temperatures to obtain the sensitivity compensation function specifically includes:

and fitting the sensitivity values which are not subjected to temperature compensation at different temperatures in a curve fitting manner to obtain the sensitivity compensation function, wherein the sensitivity compensation function is a third-order polynomial as follows:

b_t'＝s₀+s₁t+s₂t²+s₃t³

wherein, b_t' is a sensitivity compensation value at the temperature value obtained in advance; t is the temperature value; s₀、s₁、s₂And s₃Constant term coefficients, first term coefficients, second term coefficients and third term coefficients, respectively.

Optionally, the sensitivity values without temperature compensation at different temperatures are obtained by using the following formula:

b_t＝b₀+β(t-t₀)×F.S.

wherein, b_tThe sensitivity values at the different temperatures are not subjected to temperature compensation; β is the sensitivity coefficient of the pressure sensor; t is the temperature value; t is t₀The temperature value is the temperature value corresponding to the normal temperature; and F.S. is the upper limit value of the measuring range of the pressure sensor.

Optionally, converting the compensation pressure value into an analog signal and then outputting the analog signal specifically includes:

and converting the digital signal of the compensation pressure value into a current signal of 4mA-20mA and then outputting the current signal.

As another technical solution, the present invention also provides a pressure detecting system, including: a pressure sensor, a temperature sensor, a signal processing module, an AD conversion module, a processor and a DA conversion module, wherein,

the pressure sensor is used for detecting the pressure of the fluid in real time and outputting a pressure value;

the temperature sensor is used for detecting the temperature of the fluid in real time and outputting a temperature value;

the signal processing module is used for converting the electric signals corresponding to the pressure value and the temperature value into voltage signals;

the AD conversion module is used for converting the voltage signals corresponding to the pressure value and the temperature value into digital signals;

the processor is used for performing temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression so as to obtain a compensation pressure value under the temperature value; and

and the DA conversion module is used for converting the compensation pressure value into an analog signal and then outputting the analog signal.

Optionally, the pressure detection system further includes:

and the display module is used for receiving and displaying the compensation pressure value.

The invention has the following beneficial effects:

according to the technical scheme of the pressure detection method and the pressure detection system, the pressure value of the fluid detected and output by the pressure sensor and the temperature value of the fluid detected and output by the temperature sensor are obtained in real time, the pressure value and the temperature value are converted into digital signals, and the digital signals can be correspondingly processed by software to realize temperature compensation, namely, the converted pressure value is subjected to temperature compensation according to the converted temperature value by using a preset temperature compensation relational expression to obtain a compensation pressure value under the temperature value; and then converting the compensation pressure value into an analog signal and outputting the analog signal. Therefore, the pressure value detected and output by the pressure sensor can be compensated in real time, so that the compensation pressure value can be obtained immediately, and meanwhile, because the processing process does not need to use a hardware circuit, the problems of complex design, difficult debugging, poor precision and the like caused by the compensation of the hardware circuit are avoided, and the compensation precision can be improved.

Drawings

FIG. 1 is a block flow diagram of a pressure detection method according to an embodiment of the present invention;

FIG. 2 is a block flow diagram of a method for obtaining a zero-point compensation pressure function and a sensitivity compensation function as utilized in an embodiment of the present invention;

FIG. 3 is a graph comparing pressure set points at different temperatures to pressure values output by a pressure sensor without temperature compensation;

FIG. 4 is a graph comparing pressure set points at different temperatures to temperature compensated pressure values;

FIG. 5 is a schematic block diagram of a pressure detection system provided by an embodiment of the present invention;

fig. 6 is another schematic block diagram of a pressure detection system according to an embodiment of the present invention.

Detailed Description

In order to make those skilled in the art better understand the technical solution of the present invention, the following describes the pressure detection method and the pressure detection system provided by the present invention in detail with reference to the accompanying drawings.

The pressure detection method provided by the embodiment of the invention can be applied to semiconductor processing equipment, such as cleaning machines, chemical mechanical polishing equipment and other equipment needing to detect the pressure of fluid, such as liquid or gas. Specifically, the method can be used for detecting the pressure value of the fluid in real time and performing temperature compensation on line, namely, calibrating zero drift and sensitivity drift generated by the pressure value detected and output by the pressure sensor and outputting the calibrated compensated pressure value in real time. Specifically, referring to fig. 1, the pressure detection method includes:

step 101, acquiring a pressure value of a fluid detected and output by a pressure sensor and a temperature value of the fluid detected and output by a temperature sensor in real time;

the pressure sensor is used for outputting a pressure value after detecting the pressure of the fluid. The temperature sensor is used for outputting a temperature value after detecting the temperature of the fluid. The pressure sensor and the temperature sensor may convert the pressure signal and the temperature signal sensed by the pressure sensor and the temperature sensor into electric signals (analog signals) and output the electric signals. Step 101 is used to acquire the electrical signal in real time.

Step 102, converting the pressure value and the temperature value into digital signals;

step 102 is configured to convert the analog signals output by the pressure sensor and the temperature sensor, which are acquired in real time, into digital signals, so that the digital signals can be correspondingly processed through software, that is, temperature compensation is performed through software.

103, performing temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression to obtain a compensation pressure value under the temperature value;

by means of the temperature compensation relational expression, the compensation pressure value after temperature compensation under the current acquired temperature value can be calculated and obtained, and temperature compensation is achieved.

And 104, converting the compensation pressure value into an analog signal and outputting the analog signal.

The compensation pressure value is converted into an analog signal and then output through the step 104, which is convenient for sending an instruction to a corresponding execution unit to realize automatic control.

The pressure detection method provided by the embodiment of the invention can realize online temperature compensation of the pressure value output by the pressure sensor by using software without using a hardware circuit, and avoids the problems of complex design, difficult debugging, poor precision and the like caused by hardware circuit compensation, thereby improving the compensation precision.

There are many temperature compensation relations that can implement temperature compensation, for example, the temperature compensation relation may be:

wherein, U_t' is the compensation pressure value under the temperature value;

U_tis the pressure value detected by the pressure sensor at the above temperature value (i.e., the pressure value output by the pressure sensor without temperature compensation);

a₀is the zero-point pressure value (without compensation) output by the pressure sensor when the temperature of the fluid is a normal temperature value (for example, 25 ℃) and the pressure value of the fluid is 0 Psig;

b₀when the temperature value of the fluid is a normal temperature value and the pressure value of the fluid is 0Psig, the sensitivity value of the pressure sensor is not compensated;

a_t' is a zero point compensation pressure value (after compensation) obtained in advance at the temperature value;

b_t' is a sensitivity compensation value (after compensation) at the above temperature value obtained in advance;

t is the above temperature value.

In the temperature compensation relation, the zero point compensation pressure value a_t' and sensitivity compensation value b_t' are known, and are obtained in advance, for example, by any means such as experiments, experience, and the like, and stored. In addition, the temperature value t and the zero point compensation pressure value a_t' and sensitivity compensation value b_t' is a one-to-one correspondence.

The pressure value of the fluid refers to a preset pressure value of the fluid, which is generally controlled by a pressure controller of the fluid, for example, for the fluid in a pipeline, the pressure controller is a pressure control valve disposed on the pipeline, and the pressure value of the fluid is a pressure value input to the pressure control valve.

The zero pressure is a pressure value that is output by the pressure sensor after the pressure value of the fluid is acquired when the pressure value of the fluid is 0psig (dead per square inch). The zero pressure is ideally constant without changing with the external environment, but when the temperature of the fluid changes, the zero pressure of the pressure sensor is shifted, which is called zero drift. The zero compensation pressure value a_tThe zero point pressure value is obtained after zero point compensation is carried out on the zero point pressure.

The sensitivity is a ratio of a change amount of the voltage value output from the pressure sensor to a change amount of a set pressure value (a preset pressure value of the fluid). The sensitivity is ideally constant without changing with changes in the external environment, but when the temperature of the fluid changes, the sensitivity of the pressure sensor also shifts, which is referred to as sensitivity drift. The sensitivity compensationCompensation b_tThe' is the sensitivity value after sensitivity compensation to the sensitivity.

In some alternative embodiments, the zero-point compensation pressure value a is_t' is obtained based on the temperature value detected by the temperature sensor and a preset zero point pressure compensation function, and the sensitivity compensation value b_t' is obtained based on a temperature value detected by the temperature sensor and a preset sensitivity compensation function. As shown in fig. 2, the zero point pressure compensation function and the sensitivity compensation function may be obtained by:

step 201, selecting a plurality of set pressure values in a measuring range of a pressure sensor, wherein the plurality of set pressure values comprise 0 Psig;

the set pressure value is a preset pressure value of the fluid, the pressure value is generally controlled by a pressure controller of the fluid, for example, for the fluid in the pipeline, the pressure controller is a pressure control valve arranged on the pipeline, and the set pressure value is a pressure value input to the pressure control valve.

Step 202, acquiring pressure groups corresponding to a plurality of set pressure values one by one, wherein each pressure group comprises pressure values output by the pressure sensors at different temperatures of the set pressure values corresponding to the pressure group, and the pressure value group corresponding to 0Psig is a zero-point pressure value group;

table 1 is a data table of pressure groups in one-to-one correspondence with a plurality of set pressure values.

For example, as shown in table 1, in step 201, n set pressure values (P1, P2.., Pn) are selected within the range of the pressure sensor. The n set pressure values include 0 Psig. In the above step 202, each set pressure value corresponds to a group of pressure groups, each pressure group including m output pressure values (uncompensated) at m temperature values (T1, T2,. gtoreq., Tm), for example, the pressure group corresponding to the set pressure value P1 includes m output pressure values (U11, U21, Um1) at m temperature values (T1, T2,. gtoreq.,. Tm); the pressure group corresponding to the set pressure value P2 includes m output pressure values (U12, U22, Um2) at m temperature values (T1, T2.., Tm); the pressure group corresponding to the set pressure value Pn includes m output pressure values (U1n, U2n, Umn) at m temperature values (T1, T2,. Tm), where the pressure group corresponding to the set pressure value of 0Psig is a zero-point pressure value group.

Step 203, obtaining zero point pressure values which are not subjected to temperature compensation at different temperatures according to pressure values output by the pressure sensors at different temperatures in the zero point pressure value group;

for example, the following formula can be used to obtain the zero pressure values without temperature compensation at different temperatures:

a_t＝a₀+α(t-t₀)×F.S.

wherein, a_tThe zero pressure value is not subjected to temperature compensation at different temperatures; α is a zero point coefficient at a normal temperature (e.g., 25 ℃) of the fluid and a pressure of the fluid of 0 Psig; f.s. is the upper limit value of the range of the pressure sensor (also called full range); t is t₀Is the temperature value corresponding to the normal temperature.

For example, the m temperature values (T1, T2.., Tm) correspond to m zero pressure values (a1, a 2.., am) without temperature compensation.

204, obtaining sensitivity values which are not subjected to temperature compensation at different temperatures according to the pressure groups which are in one-to-one correspondence with the plurality of set pressure values;

for example, the following formula can be used to obtain the sensitivity values without temperature compensation at different temperatures:

b_t＝b₀+β(t-t₀)×F.S.

wherein, b_tSensitivity values without temperature compensation at different temperatures; beta is the sensitivity coefficient of the pressure sensor; t is a temperature value; t is t₀The temperature value is the corresponding temperature value of the normal temperature; and F.S. is the upper limit value of the measuring range of the pressure sensor.

For example, m temperature values (T1, T2.., Tm) correspond to m sensitivity values (b1, b 2.., bm) that are not temperature compensated.

It should be noted that, in practical applications, the step 203 and the step 204 may be performed sequentially in any order, or may also be performed simultaneously.

Step 205, fitting zero pressure values which are not subjected to temperature compensation at different temperatures to obtain a zero pressure compensation function;

there may be a plurality of methods for obtaining the zero-point pressure compensation function by fitting, for example, the step 205 specifically includes:

and fitting the zero pressure values which are not subjected to temperature compensation at different temperatures in a curve fitting manner to obtain the zero pressure compensation function, wherein the zero pressure compensation function is a third-order polynomial as follows:

a_t'＝k₀+k₁t+k₂t²+k₃t³。

wherein, a_t' is a zero point compensation pressure value under a temperature value obtained in advance; t is a temperature value; k is a radical of₀、k₁、k₂And k₃Constant term coefficients, first term coefficients, second term coefficients and third term coefficients, respectively.

For example, the m temperature values (T1, T2.., Tm) correspond to m temperature uncompensated zero pressure values (a1, a 2.., am), and the third-order polynomial is obtained by curve fitting the m temperature uncompensated zero pressure values (a1, a 2.., am).

And step 206, fitting the sensitivity values which are not subjected to temperature compensation at different temperatures to obtain a sensitivity compensation function.

There are various methods for obtaining the sensitivity compensation function by fitting, for example, the step 206 specifically includes:

for the sensitivity values which are not subjected to temperature compensation at different temperatures, a curve fitting mode is adopted to fit and obtain a sensitivity compensation function, and the sensitivity compensation function is a third-order polynomial as follows:

b_t'＝s₀+s₁t+s₂t²+s₃t³

wherein, b_t' is a sensitivity compensation value at a temperature value obtained in advance; t is a temperature value; s₀、s₁、s₂And s₃Constant term coefficients, first term coefficients, second term coefficients and third term coefficients, respectively.

For example, the m temperature values (T1, T2.., Tm) correspond to m sensitivity values (b1, b 2.., bm) without temperature compensation, and the third-order polynomial is obtained by fitting a curve to the m sensitivity values (b1, b 2.., bm) without temperature compensation.

It should be noted that, in practical applications, the step 205 and the step 206 may be performed sequentially in any order, or may also be performed simultaneously.

It should be further noted that, in practical applications, any other fitting method may be adopted to obtain the zero-point pressure compensation function and the sensitivity compensation function, and the present invention is not particularly limited to this.

In some optional embodiments, the step 104 specifically includes:

and converting the digital signal of the compensated pressure value into a current signal (analog signal) of 4mA-20mA, and then outputting the current signal.

By converting the digital signal into a current signal (analog signal) of 4mA-20mA, the compensated pressure value after temperature compensation can still be output as an analog signal, and the current range is usually the current range of the output signal of the pressure sensor, so that the output signal is the same as the type of the output signal when the pressure sensor is not compensated.

FIG. 3 is a graph comparing pressure set points at different temperatures to pressure values output by a pressure sensor without temperature compensation. The four curves (a1, a2, A3, a4) in fig. 3 respectively show the corresponding relationship between the pressure set value at the four temperature values (0 ℃, 20 ℃, 40 ℃, 60 ℃) and the pressure value output by the pressure sensor without temperature compensation, and as can be seen from fig. 3, the four curves (a1, a2, A3, a4) do not substantially overlap, so that it can be shown that the corresponding relationship between the pressure set value and the pressure value output by the pressure sensor without temperature compensation is greatly influenced by the ambient temperature. In contrast, FIG. 4 is a graph comparing pressure set points at different temperatures to temperature compensated pressure values. The four curves in fig. 4 respectively show the corresponding relationship between the pressure set value and the temperature compensated pressure value at four temperature values (0 ℃, 20 ℃, 40 ℃, 60 ℃), and as can be seen from fig. 4, most of the four curves are overlapped and approach to form a curve B, so that it can be illustrated that the corresponding relationship between the pressure set value and the temperature compensated pressure value is less affected by the ambient temperature, that is, the temperature compensation is realized.

In the pressure detection method provided by the embodiment of the invention, the pressure value detected and output by the pressure sensor and the temperature value of the fluid detected by the temperature sensor are obtained in real time, the pressure value and the temperature value are converted into digital signals, and the digital signals can be correspondingly processed by software to realize temperature compensation, namely, the converted pressure value is subjected to temperature compensation according to the converted temperature value by using a preset temperature compensation relational expression to obtain the compensation pressure value under the temperature value; and then converting the compensation pressure value into an analog signal and outputting the analog signal. Therefore, the pressure value detected and output by the pressure sensor can be compensated in real time, so that the compensation pressure value can be obtained immediately, and meanwhile, because the processing process does not need to use a hardware circuit, the problems of complex design, difficult debugging, poor precision and the like caused by the compensation of the hardware circuit are avoided, and the compensation precision can be improved.

As another technical solution, referring to fig. 5, an embodiment of the invention further provides a pressure detection system 1, which can be applied to semiconductor processing equipment. The pressure detection system 1 is used for detecting the pressure value of the fluid in real time and performing temperature compensation on line, namely calibrating zero drift and sensitivity drift generated by the pressure value detected and output by the pressure sensor and outputting the calibrated compensation pressure value in real time.

Specifically, the pressure detection system 1 includes a pressure sensor 11, a temperature sensor 12, a signal processing module 13, an AD conversion module 14, a processor 15, and a DA conversion module 16, where the pressure sensor 11 is configured to detect the pressure of the fluid in real time and output a pressure value; the temperature sensor 12 is used for detecting the temperature of the fluid in real time and outputting a temperature value; the signal processing module 13 is configured to convert the electrical signals corresponding to the pressure value and the temperature value into voltage signals, and optionally, the signal processing module 11 may include a voltage signal processing module integrated on the pressure sensor 11 and a temperature signal processing module integrated on the temperature sensor 12, or may also be a processing module independent from the pressure sensor 11 and the temperature sensor 12; the AD conversion module 14 is configured to convert the voltage signals corresponding to the pressure value and the temperature value into digital signals; the processor 15 is configured to perform temperature compensation on the converted pressure value according to the converted temperature value by using a preset temperature compensation relational expression to obtain a compensation pressure value at the temperature value; and the DA conversion module 16 is configured to convert the compensated pressure value into an analog signal and output the analog signal.

In some alternative embodiments, as shown in fig. 6, the pressure detection system 1 further includes a battery processing module 17 for supplying power to the corresponding components and modules, such as the pressure sensor 11, the temperature sensor 12, the signal processing module 13, the AD conversion module 14, the controller 15, and the like.

In some optional embodiments, the pressure detection system 1 further comprises a display module 18 for receiving and displaying the compensated pressure value. The display module 18 is used for displaying the compensation pressure value in real time, so that the operation is convenient and the management is convenient.

The pressure detection system 1 can be applied to semiconductor processing equipment, such as a cleaning machine, a chemical mechanical polishing device and other equipment needing to detect the pressure of fluid, and is specifically used for detecting the pressure of the fluid and immediately outputting a pressure value after temperature compensation.

The pressure detection system 1 provided by the embodiment of the invention can compensate the pressure value detected and output by the pressure sensor in real time, so that the compensation pressure value can be obtained immediately, and meanwhile, as the processing process does not need to use a hardware circuit, the problems of complex design, difficult debugging, poor precision and the like caused by hardware circuit compensation are avoided, so that the compensation precision can be improved.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.