Vacuum butterfly valve inlet pressure data acquisition system

Abstract

This application relates to the field of vacuum butterfly valve technology, specifically providing a vacuum butterfly valve inlet pressure data acquisition system, which includes: a pressure signal acquisition module connected to a pressure sensor at the inlet of the vacuum butterfly valve, comprising an amplification circuit and a low-pass filter circuit; an analog-to-digital conversion module for converting a pre-processed analog pressure signal into a digital pressure signal; a temperature detection unit for acquiring ambient temperature information; a gas type detection unit for acquiring gas type information entering the vacuum butterfly valve; a gas molecule characteristic calculation unit for calculating gas molecule characteristic parameters based on the digital pressure signal, ambient temperature information, and gas type information; and a pressure correction unit for generating a corrected analog pressure signal based on the digital pressure signal, gas molecule characteristic parameters, ambient temperature information, and the pre-processed analog pressure signal; it is capable of dynamically and adaptively correcting the pre-processed analog pressure signal based on the microscopic physical properties of gas molecules.

Description

Technical Field

[0001] This application relates to the field of vacuum butterfly valve technology, and more specifically, to a vacuum butterfly valve inlet pressure data acquisition system. Background Technology

[0002] Vacuum butterfly valves are key control components in devices used in semiconductor manufacturing, optoelectronic thin film deposition, vacuum metallurgy, space simulation, and high-energy physics experiments. The stability and accurate detection of their inlet pressure are crucial for maintaining the reliability of the vacuum system. To achieve high-precision vacuum control, a pressure sensor is typically installed at the inlet of the butterfly valve, along with a corresponding data acquisition system to convert the analog pressure signal into a digital signal that can be processed by the control system.

[0003] In existing technologies, pressure acquisition circuits mostly employ traditional amplification and filtering circuits, analog-to-digital converters (ADCs), and temperature compensation logic to achieve real-time pressure acquisition by amplifying, filtering, and digitizing the voltage or current signals output by the sensor. However, when the system is in a high vacuum or mixed gas environment, the mean free path of gas molecules increases significantly, the collision frequency between molecules decreases sharply, and the molecular kinetic energy distribution and diffusion characteristics change, causing a nonlinear deviation between the pressure sensor output signal and the actual pressure.

[0004] Furthermore, traditional pressure acquisition circuits often rely on empirical formulas or static temperature correction parameters for compensation, failing to adequately consider the impact of gas composition differences and molecular motion on pressure response. When the gas type or temperature changes, the compensation effect of traditional pressure acquisition circuits significantly decreases, especially in multi-component gas, high-temperature, or strong electromagnetic interference environments. This often leads to problems such as zero-point drift, sensitivity decay, and measurement instability in traditional pressure acquisition circuits, making it difficult to guarantee long-term consistency of pressure measurements.

[0005] There is currently no effective technical solution to the above problems. Summary of the Invention

[0006] The purpose of this application is to provide a vacuum butterfly valve inlet pressure data acquisition system that can dynamically and adaptively correct the pre-processed simulated pressure signal based on the microscopic physical properties of gas molecules.

[0007] This application provides a vacuum butterfly valve inlet pressure data acquisition system, which includes:

[0008] The pressure signal acquisition module is connected to the pressure sensor at the inlet of the vacuum butterfly valve. It includes an amplification circuit and a low-pass filter circuit, which are used to preprocess the analog pressure signal acquired by the pressure sensor. The preprocessing includes signal amplification and filtering.

[0009] The analog-to-digital conversion module, connected to the pressure signal acquisition module, is used to convert the preprocessed analog pressure signal into a digital pressure signal;

[0010] Temperature detection unit, used to collect ambient temperature information;

[0011] The gas type detection unit is used to collect information on the type of gas entering the vacuum butterfly valve;

[0012] The gas molecule characteristic calculation unit, connected to the analog-to-digital conversion module, temperature detection unit, and gas type detection unit, is used to calculate gas molecule characteristic parameters based on digital pressure signals, ambient temperature information, and gas type information. The gas molecule characteristic parameters include gas molecule collision frequency, diffusion coefficient, and average kinetic energy.

[0013] The pressure correction unit, connected to the pressure signal acquisition module, analog-to-digital conversion module, gas molecule characteristic calculation unit, and temperature detection unit, is used to generate a corrected analog pressure signal based on the digital pressure signal, gas molecule characteristic parameters, ambient temperature information, and preprocessed analog pressure signal.

[0014] This application provides a vacuum butterfly valve inlet pressure data acquisition system. By introducing a gas molecule characteristic calculation unit 6 and a pressure correction unit 7, it achieves dynamic and accurate acquisition and correction of vacuum butterfly valve inlet pressure data. Because this application can dynamically calculate gas molecule characteristic parameters such as collision frequency, diffusion coefficient, and average kinetic energy based on real-time acquired digital pressure signals, ambient temperature information, and gas type information, and generate a corrected simulated pressure signal by correcting the pre-processed simulated pressure signal based on these gas molecule characteristic parameters, this application is equivalent to dynamically and adaptively correcting the pre-processed simulated pressure signal based on the microscopic physical properties of gas molecules. Therefore, this application can effectively solve the problems of nonlinear deviation and insufficient compensation strategies caused by changes in gas molecule behavior in high vacuum or mixed gas environments using traditional methods. This effectively improves the long-term consistency and accuracy of pressure measurement, and consequently, effectively improves the reliability and precision of the vacuum control system.

[0015] Optionally, the process by which the gas molecule characteristic calculation unit calculates gas molecule characteristic parameters based on digital pressure signals, ambient temperature information, and gas type information includes:

[0016] A1. Obtain the gas molecule diameter and gas molecule mass corresponding to the gas type information;

[0017] A2. Calculate the mean free path of gas molecules based on ambient temperature information, gas molecule diameter, and digital pressure signal;

[0018] A3. Calculate the average velocity of gas molecules based on ambient temperature information and gas molecule mass;

[0019] A4. Calculate the collision frequency of gas molecules based on the average velocity and mean free path of gas molecules;

[0020] A5. Calculate the average kinetic energy based on ambient temperature information;

[0021] A6. Calculate the diffusion coefficient based on the average gas velocity and the mean free path of gas molecules.

[0022] Optionally, the formula for calculating the mean free path of gas molecules is as follows:

[0023] ;

[0024] in, The mean free path of gas molecules is represented by , k represents the Boltzmann constant, T represents the ambient temperature information, π represents pi, d represents the diameter of gas molecules, and P represents the digital pressure signal.

[0025] The formula for calculating the average velocity of gas molecules is shown below:

[0026] ;

[0027] in, represents the average velocity of gas molecules, and m represents the mass of a gas molecule;

[0028] The formula for calculating the collision frequency of gas molecules is shown below:

[0029] ;

[0030] Where represents the collision frequency of gas molecules;

[0031] The formula for calculating the mean kinetic energy is as follows:

[0032] ;

[0033] in, This represents the average kinetic energy.

[0034] The formula for calculating the diffusion coefficient is shown below:

[0035] ;

[0036] in, This represents the diffusion coefficient.

[0037] Optionally, the pressure correction unit includes a pre-built virtual gas state model, a correction factor adaptive adjustment module, and a correction module. The input of the virtual gas state model is connected to the temperature acquisition unit, the gas type detection unit, and the gas molecule characteristic calculation unit. The correction factor adaptive adjustment module is connected to the output of the virtual gas state model and the pressure signal acquisition module. The correction module is connected to the pressure signal acquisition module, the gas molecule characteristic calculation unit, and the correction factor adaptive adjustment module. The virtual gas state model is used to generate a predicted pressure signal based on ambient temperature information, gas type information, and gas molecule characteristic parameters. The correction factor adaptive adjustment module is used to determine the target correction factor based on the deviation between the predicted pressure signal and the pre-processed simulated pressure signal. The correction module is used to generate a corrected simulated pressure signal based on the target correction factor, gas molecule characteristic parameters, and the pre-processed simulated pressure signal according to a preset recursive update equation.

[0038] Alternatively, the recursive update equation is shown below:

[0039] ;

[0040] in, This indicates a correction to the analog pressure signal. This represents the preprocessed simulated pressure signal at time t. The target correction factor is represented at time t. This represents the collision frequency of gas molecules at time t. The diffusion coefficient at time t is represented. It represents the average kinetic energy at time t.

[0041] Optionally, the pressure signal acquisition module also includes a temperature compensation circuit, with the amplification circuit, low-pass filter circuit and temperature compensation circuit connected in sequence, and the preprocessing also includes temperature compensation processing.

[0042] This technical solution introduces a temperature compensation circuit into the pressure signal acquisition module and connects it sequentially with the amplification circuit and low-pass filter circuit. This allows the analog pressure signal to undergo further temperature compensation processing after amplification and filtering, ensuring that temperature drift is effectively suppressed before digitization. This significantly improves the accuracy and stability of pressure signal acquisition. Therefore, this solution ensures that the analog signal output by the pressure sensor can be accurately corrected even in environments with large temperature fluctuations. This provides a more reliable and stable data source for subsequent analog-to-digital conversion modules, gas molecule characteristic calculation units, and pressure correction units, thereby effectively improving the measurement accuracy and long-term operational stability of the vacuum butterfly valve inlet pressure data acquisition system.

[0043] Optionally, the temperature compensation circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first sliding rheostat, a second sliding rheostat, a third sliding rheostat, a temperature sensor, a first capacitor, a second capacitor, an operational amplifier, and a Wheatstone bridge. One end of the first resistor is connected to the output of the low-pass filter circuit, and the other end of the first resistor is connected to one end of the first sliding rheostat, one end of the temperature sensor, and one end of the third resistor, respectively. One end of the second resistor is connected to the output of the operational amplifier and the other end of the temperature sensor, respectively. The other end of the second resistor is connected to the input of the analog-to-digital converter module, and the other end of the third resistor is connected to the ground terminal. One end of the fourth resistor is connected to the first sliding rheostat. The other end of the fourth resistor is connected to one end of the fifth resistor and the inverting input of the operational amplifier. The other end of the fourth resistor is connected to one end of the second and third sliding rheostats respectively. The other end of the fifth resistor is connected to one end of the seventh resistor and one end of the first capacitor respectively. One end of the sixth resistor is connected to one end of the eighth resistor and one end of the second capacitor respectively. The other end of the sixth resistor is connected to the non-inverting input of the operational amplifier. The other ends of the first and second capacitors are both connected to the ground terminal. The other end of the second sliding rheostat is connected to the output terminal of the low-pass filter circuit. The other end of the third sliding rheostat is connected to the ground terminal. The Wheatstone bridge is connected to the output terminal of the low-pass filter circuit, the other end of the seventh resistor, the other end of the eighth resistor, and the ground terminal respectively.

[0044] Optionally, the analog-to-digital conversion module uses a Sigma-Delta type ADC chip and is equipped with a multi-stage digital filter.

[0045] Optionally, the vacuum butterfly valve inlet pressure data acquisition system also includes an isolation drive unit, which includes an opto-isolation chip and an isolation power supply module. The isolation drive unit is used to electrically isolate the pressure signal acquisition module, analog-to-digital conversion module, temperature detection unit, gas type detection unit, gas molecule characteristic calculation unit, and pressure correction unit from the actuator of the vacuum butterfly valve.

[0046] Optionally, the vacuum butterfly valve inlet pressure data acquisition system also includes a self-diagnostic module. The self-diagnostic module is used to trigger the gas molecule characteristic calculation unit to recalculate the gas molecule characteristic parameters based on the preset reference pressure signal and the ambient temperature and gas type information at the current moment when the deviation between the simulated pressure signal at the current moment and the simulated pressure signal at the previous moment or the preset reference pressure signal is greater than a first preset threshold, the power supply voltage of the vacuum butterfly valve inlet pressure data acquisition system is outside the preset voltage range, or the rate of decrease of the power supply voltage is greater than a second preset threshold.

[0047] As can be seen from the above, the vacuum butterfly valve inlet pressure data acquisition system provided in this application, by introducing a gas molecule characteristic calculation unit 6 and a pressure correction unit 7, realizes dynamic and accurate acquisition and correction of vacuum butterfly valve inlet pressure data. Since this application can dynamically calculate gas molecule characteristic parameters such as gas molecule collision frequency, diffusion coefficient and average kinetic energy based on the real-time acquired digital pressure signal, ambient temperature information and gas type information, and generate a corrected simulated pressure signal by correcting the pre-processed simulated pressure signal based on the gas molecule characteristic parameters, this application is equivalent to dynamically and adaptively correcting the pre-processed simulated pressure signal based on the microscopic physical properties of gas molecules. Therefore, this application can effectively solve the problems of nonlinear deviation and insufficient compensation strategy caused by changes in gas molecule behavior in high vacuum or mixed gas environments by traditional methods, thereby effectively improving the long-term consistency and accuracy of pressure measurement, and thus effectively improving the reliability and accuracy of vacuum control system. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of a vacuum butterfly valve inlet pressure data acquisition system provided in an embodiment of this application.

[0049] Figure 2 This is a schematic diagram of the temperature compensation circuit provided in an embodiment of this application.

[0050] Reference numerals: 1. Pressure sensor; 2. Pressure signal acquisition module; 3. Analog-to-digital conversion module; 4. Temperature detection unit; 5. Gas type detection unit; 6. Gas molecule characteristic calculation unit; 7. Pressure correction unit; 8. Wheatstone bridge; R1. First resistor; R2. Second resistor; R3. Third resistor; R4. Fourth resistor; R5. Fifth resistor; R6. Sixth resistor; R7. Seventh resistor; R8. Eighth resistor; RP1. First sliding rheostat; RP2. Second sliding rheostat; RP3. Third sliding rheostat; C1. First capacitor; C2. Second capacitor; RT. Temperature sensor; IC. Operational amplifier. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0052] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0053] This application provides a vacuum butterfly valve inlet pressure data acquisition system, which includes:

[0054] The pressure signal acquisition module 2 is connected to the pressure sensor at the inlet of the vacuum butterfly valve. It includes an amplification circuit and a low-pass filter circuit, which are used to preprocess the analog pressure signal acquired by the pressure sensor. The preprocessing includes signal amplification and filtering.

[0055] Analog-to-digital conversion module 3 is connected to pressure signal acquisition module 2 and is used to convert the preprocessed analog pressure signal into a digital pressure signal.

[0056] Temperature detection unit 4 is used to collect ambient temperature information;

[0057] Gas type detection unit 5 is used to collect information on the type of gas entering the vacuum butterfly valve;

[0058] The gas molecule characteristic calculation unit 6 is connected to the analog-to-digital conversion module 3, the temperature detection unit 4, and the gas type detection unit 5. It is used to calculate gas molecule characteristic parameters based on digital pressure signals, ambient temperature information, and gas type information. The gas molecule characteristic parameters include gas molecule collision frequency, diffusion coefficient, and average kinetic energy.

[0059] The pressure correction unit 7 is connected to the pressure signal acquisition module 2, the analog-to-digital conversion module 3, the gas molecule characteristic calculation unit 6, and the temperature detection unit 4. It is used to generate a corrected analog pressure signal based on the digital pressure signal, gas molecule characteristic parameters, ambient temperature information, and the pre-processed analog pressure signal.

[0060] This application introduces a gas molecule characteristic calculation unit 6 and a pressure correction unit 7, which can calculate gas molecule characteristic parameters based on gas type, ambient temperature and digital pressure signal, and correct the preprocessed analog pressure signal based on these parameters. This effectively overcomes the problem of insufficient measurement accuracy of traditional pressure acquisition circuits in complex vacuum environments, and thus effectively improves the accuracy and stability of vacuum butterfly valve inlet pressure data acquisition.

[0061] To better understand the technical solutions proposed in this application, some key terms involved in this application are explained below. The vacuum butterfly valve in this embodiment is a valve used to control gas flow in a vacuum system, and its inlet pressure is an important parameter for maintaining stable system operation. The pressure sensor in this embodiment is a device that converts pressure signals into electrical signals. The output of the pressure sensor is typically an analog voltage signal or an analog current signal (i.e., an analog pressure signal). The digital pressure signal in this embodiment refers to the pressure signal represented by discrete values ​​obtained after analog-to-digital conversion of the analog pressure signal. The ambient temperature information in this embodiment refers to the temperature data of the working environment of the vacuum butterfly valve. The gas type information in this embodiment refers to the type of gas entering the vacuum butterfly valve, such as nitrogen, oxygen, argon, etc. The gas molecule characteristic parameters of this embodiment refer to physical quantities that describe the motion and interaction characteristics of gas molecules. These gas molecule characteristic parameters include gas molecule collision frequency, diffusion coefficient, and average kinetic energy. Specifically, the gas molecule collision frequency of this embodiment refers to the number of collisions between gas molecules entering the vacuum butterfly valve inlet per unit time. The diffusion coefficient of this embodiment refers to a physical quantity that describes the diffusion ability of gas molecules entering the vacuum butterfly valve inlet. The average kinetic energy of this embodiment refers to the average kinetic energy of gas molecules entering the vacuum butterfly valve inlet.

[0062] The vacuum butterfly valve inlet pressure data acquisition system provided in this application includes a pressure signal acquisition module 2, an analog-to-digital conversion module 3, a temperature detection unit 4, a gas type detection unit 5, a gas molecule characteristic calculation unit 6, and a pressure correction unit 7. In this embodiment, the pressure signal acquisition module 2 is connected to the pressure sensor at the inlet of the vacuum butterfly valve. The pressure signal acquisition module 2 includes an amplification circuit and a low-pass filter circuit. The pressure signal acquisition module 2 is used to preprocess the analog pressure signal acquired by the pressure sensor. The preprocessing includes signal amplification and filtering. Preferably, the input terminal of the amplification circuit in this embodiment is connected to the pressure sensor, and the input terminal of the amplification circuit is connected to the input terminal of the low-pass filter circuit. That is, this embodiment is equivalent to first amplifying the analog pressure signal and then performing low-pass filtering on the amplified analog pressure signal. For example, the amplification circuit in this embodiment includes an operational amplifier IC, which is used to amplify the weak analog signal output by the pressure sensor to improve the signal-to-noise ratio and measurement accuracy of the analog pressure signal. The low-pass filter module in this embodiment includes an RC low-pass filter or an active low-pass filter, which can filter the amplified analog pressure signal to remove high-frequency noise and interference, thereby effectively improving the purity of the analog pressure signal. In this embodiment, the analog-to-digital conversion module 3 is connected to the pressure signal acquisition module 2. The analog-to-digital conversion module 3 is used to convert the preprocessed analog pressure signal into a digital pressure signal. Preferably, the analog-to-digital conversion module 3 is an existing analog-to-digital converter. In this embodiment, the temperature detection unit 4 is used to acquire ambient temperature information. This temperature detection unit 4 can be an existing thermistor or thermocouple, etc., which can convert ambient temperature into an electrical signal and output it through a corresponding conditioning circuit. In this embodiment, the gas type detection unit 5 is used to acquire information about the type of gas entering the vacuum butterfly valve. This gas type detection unit 5 can be an existing mass spectrometer or gas chromatograph, etc., which can analyze gas components and output gas type information. It should be understood that if the type of gas entering the vacuum butterfly valve is known and does not change, this embodiment also obtains the gas type information by manually inputting the gas type or reading it from a preset database. In this embodiment, the gas molecule characteristic calculation unit 6 is connected to the analog-to-digital conversion module 3, the temperature detection unit 4, and the gas type detection unit 5. The gas molecule characteristic calculation unit 6 is used to calculate gas molecule characteristic parameters based on digital pressure signals, ambient temperature information, and gas type information. These gas molecule characteristic parameters include gas molecule collision frequency, diffusion coefficient, and average kinetic energy. The gas molecule characteristic calculation unit 6 can be a microcontroller or a digital signal processor. The gas molecule characteristic calculation unit 6 can calculate the gas molecule collision frequency, diffusion coefficient, and average kinetic energy based on preset physical formulas (such as the ideal gas law, Boltzmann distribution, etc.) combined with digital pressure signals, ambient temperature information, and gas type information.In this embodiment, the pressure correction unit 7 is connected to the pressure signal acquisition module 2, the analog-to-digital conversion module 3, the gas molecule characteristic calculation unit 6, and the temperature detection unit 4. The pressure correction unit 7 is used to generate a corrected analog pressure signal based on the digital pressure signal, gas molecule characteristic parameters, ambient temperature information, and the preprocessed analog pressure signal. Specifically, this embodiment can generate a corrected analog signal by correcting the preprocessed analog pressure signal using the digital pressure signal, gas molecule characteristic parameters, and ambient temperature information. The pressure correction unit 7 can be a microcontroller or FPGA, which runs a correction algorithm. This correction algorithm can compensate the preprocessed analog pressure signal output by the pressure signal acquisition module 2 based on the digital pressure signal, gas molecule characteristic parameters, and ambient temperature information to eliminate nonlinear deviations caused by changes in the motion characteristics of gas molecules. The compensated analog pressure signal is the corrected analog pressure signal. In another implementation, the pressure correction unit 7 can use a lookup table method to correct the preprocessed analog pressure signal. That is, based on the digital pressure signal, gas molecule characteristic parameters and ambient temperature information, the corresponding correction amount is extracted from a pre-constructed mapping table of combinations of digital pressure signal, gas molecule characteristic parameters and ambient temperature and their corresponding correction amounts. Then, the correction amount is used to correct the preprocessed analog pressure signal.

[0063] The vacuum butterfly valve inlet pressure data acquisition system of this application introduces a gas molecule characteristic calculation unit 6 and a pressure correction unit 7 to calculate gas molecule characteristic parameters based on gas type, ambient temperature and digital pressure signal, and generate a corrected analog pressure signal based on digital pressure signal, gas molecule characteristic parameters, ambient temperature information and preprocessed analog pressure signal. This effectively overcomes the problem of insufficient measurement accuracy and stability of traditional pressure acquisition circuits in complex vacuum environments, thereby effectively improving the accuracy and stability of vacuum butterfly valve inlet pressure data acquisition.

[0064] Specifically, traditional pressure acquisition circuits typically employ a structure consisting of conventional amplification and filtering circuits, an analog-to-digital converter module, and temperature compensation logic. While this structure can meet basic requirements under normal pressure or low vacuum conditions, its limitations become apparent in high vacuum or mixed gas environments. For instance, when the system is in a high vacuum or mixed gas environment, the mean free path of gas molecules increases significantly, the frequency of intermolecular collisions decreases sharply, and the distribution of molecular kinetic energy and diffusion characteristics change, resulting in a nonlinear deviation between the pressure sensor output signal and the actual pressure. Traditional circuit compensation strategies often rely on empirical formulas or static temperature correction parameters, failing to fully consider the influence of differences in gas composition and molecular motion on the pressure response. This leads to a significant decrease in compensation effectiveness when the gas type or temperature changes, often resulting in zero-point drift, sensitivity attenuation, and measurement instability.

[0065] The gas molecule characteristic calculation unit 6 of this application calculates gas molecule characteristic parameters such as collision frequency, diffusion coefficient, and average kinetic energy based on digital pressure signals, ambient temperature information, and gas type information. These parameters directly reflect the motion and interaction of the gas at the microscopic level, providing a deeper physical basis for pressure correction. For example, when the gas molecule collision frequency is low, it indicates that the gas is in a high vacuum state. At this time, the pressure sensor may have nonlinear errors. This application can accurately quantify this nonlinear deviation through the calculated gas molecule characteristic parameters. Subsequently, the pressure correction unit 7 of this application generates a corrected simulated pressure signal based on the digital pressure signal, gas molecule characteristic parameters, ambient temperature information, and preprocessed simulated pressure signal. Since the correction in this application is no longer a simple empirical compensation, but a dynamic adaptive correction based on the microscopic physical properties of gas molecules, for example, in a mixed gas environment, the molecular diameters and masses of different gas components are different, resulting in differences in their collision frequencies, diffusion coefficients, and average kinetic energy.

[0066] Therefore, the vacuum butterfly valve inlet pressure data acquisition system provided in this application, by introducing a gas molecule characteristic calculation unit 6 and a pressure correction unit 7, achieves dynamic and accurate acquisition and correction of vacuum butterfly valve inlet pressure data. Since this application can dynamically calculate gas molecule characteristic parameters such as collision frequency, diffusion coefficient, and average kinetic energy based on real-time acquired digital pressure signals, ambient temperature information, and gas type information, and generate a corrected simulated pressure signal by correcting the pre-processed simulated pressure signal based on these gas molecule characteristic parameters, this application is equivalent to dynamically and adaptively correcting the pre-processed simulated pressure signal based on the microscopic physical properties of gas molecules. Therefore, this application can effectively solve the problems of nonlinear deviation and insufficient compensation strategies caused by changes in gas molecule behavior in high vacuum or mixed gas environments using traditional methods, thereby effectively improving the long-term consistency and accuracy of pressure measurement, and consequently, effectively improving the reliability and precision of the vacuum control system.

[0067] In some preferred embodiments, the process by which the gas molecule characteristic calculation unit 6 calculates gas molecule characteristic parameters based on digital pressure signals, ambient temperature information, and gas type information includes:

[0068] A1. Obtain the gas molecule diameter and gas molecule mass corresponding to the gas type information;

[0069] A2. Calculate the mean free path of gas molecules based on ambient temperature information, gas molecule diameter, and digital pressure signal;

[0070] A3. Calculate the average velocity of gas molecules based on ambient temperature information and gas molecule mass;

[0071] A4. Calculate the collision frequency of gas molecules based on the average velocity and mean free path of gas molecules;

[0072] A5. Calculate the average kinetic energy based on ambient temperature information;

[0073] A6. Calculate the diffusion coefficient based on the average gas velocity and the mean free path of gas molecules.

[0074] In step A1, the diameter and mass of gas molecules are fundamental parameters describing the physical properties of gas molecules, crucial for accurately calculating their kinematic and dynamic behavior. These parameters can be pre-stored in the memory of the gas molecule characteristic calculation unit 6 to form a gas property parameter database. When the gas type detection unit 5 identifies the current gas type, the gas molecule characteristic calculation unit 6 can use this gas type information as an index to retrieve the corresponding gas molecule diameter and mass from the gas property parameter database. In step A2, the mean free path of gas molecules refers to the average distance traveled by gas molecules between two consecutive collisions. The calculation of the mean free path of gas molecules requires comprehensive consideration of ambient temperature information, gas molecule diameter, and digital pressure signal. In a vacuum environment, the mean free path of gas molecules is a key indicator for evaluating the rarefaction level and molecular motion characteristics of a gas. In step A3, the calculation of the average velocity of gas molecules depends on ambient temperature information and gas molecule mass. Specifically, ambient temperature is a macroscopic quantity that measures the intensity of thermal motion of gas molecules, and gas molecule mass determines the kinetic energy distribution of gas molecules at a specific temperature, thus affecting their average velocity. In step A4, the calculation of the gas molecule collision frequency is based on the obtained average gas molecule velocity and mean free path. The gas molecule collision frequency reflects the average number of collisions between a single gas molecule and other molecules per unit time, and is an important parameter for understanding gas dynamics. In step A5, the average kinetic energy is a physical quantity directly related to ambient temperature information. According to thermodynamic theory, the average kinetic energy of gas molecules is proportional to absolute temperature; therefore, the average kinetic energy in this embodiment can be directly calculated using ambient temperature information. In step A6, the diffusion coefficient is calculated by combining the average gas velocity and the mean free path of the gas molecules. The diffusion coefficient describes the ability of gas molecules to migrate macroscopically under the influence of a concentration gradient, and is crucial for understanding the gas transport process in a vacuum system.

[0075] In some preferred embodiments, the formula for calculating the mean free path of gas molecules is as follows:

[0076] ;

[0077] in, The mean free path of gas molecules is represented by , k represents the Boltzmann constant, T represents the ambient temperature information, π represents pi, d represents the diameter of gas molecules, and P represents the digital pressure signal.

[0078] The formula for calculating the average velocity of gas molecules is shown below:

[0079] ;

[0080] in, represents the average velocity of gas molecules, and m represents the mass of a gas molecule;

[0081] The formula for calculating the collision frequency of gas molecules is shown below:

[0082] ;

[0083] Where represents the collision frequency of gas molecules;

[0084] The formula for calculating the mean kinetic energy is as follows:

[0085] ;

[0086] in, This represents the average kinetic energy.

[0087] The formula for calculating the diffusion coefficient is shown below:

[0088] ;

[0089] in, This represents the diffusion coefficient.

[0090] In some preferred embodiments, the pressure correction unit 7 includes a pre-built virtual gas state model, a correction factor adaptive adjustment module, and a correction module. The input of the virtual gas state model is connected to the temperature acquisition unit, the gas type detection unit 5, and the gas molecule characteristic calculation unit 6. The correction factor adaptive adjustment module is connected to the output of the virtual gas state model and the pressure signal acquisition module 2. The correction module is connected to the pressure signal acquisition module 2, the gas molecule characteristic calculation unit 6, and the correction factor adaptive adjustment module. The virtual gas state model is used to generate a predicted pressure signal based on ambient temperature information, gas type information, and gas molecule characteristic parameters. The correction factor adaptive adjustment module is used to determine the target correction factor based on the deviation between the predicted pressure signal and the pre-processed simulated pressure signal. The correction module is used to generate a corrected simulated pressure signal based on the target correction factor, gas molecule characteristic parameters, and the pre-processed simulated pressure signal according to a preset recursive update equation.

[0091] The virtual gas state model in this embodiment is a mathematical or computational model used to simulate the behavior of gases in a specific vacuum environment. This model can predict the pressure signal at the inlet of a vacuum butterfly valve under ideal conditions based on input ambient temperature information, gas type information, and gas molecule characteristic parameters. This model can be built upon existing gas dynamics theory, describing the motion and interaction of gas molecules through a series of physical equations. It should be understood that constructing a virtual gas state model based on gas dynamics theory is prior art, and its process will not be discussed in detail here. Alternatively, the model can also be a data-driven model based on machine learning algorithms. This application trains the model using a large amount of historical measurement data and corresponding environmental parameters, enabling the model to accurately predict the pressure value under specific combinations of ambient temperature information, gas type information, and gas molecule characteristic parameters. The adaptive adjustment module of this embodiment is responsible for dynamically calculating and updating a correction factor to compensate for the deviation between the virtual gas state model's predicted value and the actual measured value (the pre-processed simulated pressure signal). This module can extract the corresponding correction factor as the target correction factor from a pre-built mapping table of simulated signal deviation and correction factors based on the deviation between the predicted pressure signal and the pre-processed simulated pressure signal. The function of the correction module is to perform actual correction operations on the preprocessed simulated pressure signal based on the target correction factor determined by the correction factor adaptive adjustment module and the gas molecule characteristic parameters provided by the gas molecule characteristic calculation unit 6. This module can be implemented by a microcontroller or digital signal processor (DSP), which internally executes a preset recursive update equation. In this embodiment, the corrected simulated pressure signal is generated by substituting the correction factor, gas molecule characteristic parameters and the preprocessed simulated pressure signal into the recursive update equation.

[0092] Through the above technical solution, the vacuum butterfly valve inlet pressure data acquisition system of this application can effectively solve the problems of unstable correction effect, decreased measurement accuracy, zero drift, and sensitivity decay caused by the lack of dynamic adjustment mechanism in traditional pressure acquisition circuits under complex vacuum environments. Specifically, the introduction of a virtual gas state model enables the system to generate an ideal predicted pressure signal based on real-time ambient temperature information, gas type information, and gas molecule characteristic parameters, providing a reliable theoretical benchmark for pressure correction and avoiding the limitations of static models in dynamic environments. The adaptive adjustment module of the correction factor dynamically determines the target correction factor based on the deviation between the predicted pressure signal and the preprocessed simulated pressure signal. Since the deviation between the predicted pressure signal and the preprocessed simulated pressure signal can reflect the system error caused by factors such as temperature drift, gas type difference, or low-pressure nonlinearity, this embodiment can effectively eliminate system errors caused by factors such as temperature drift, gas type difference, or low-pressure nonlinearity by dynamically determining the target correction factor based on the deviation between the predicted pressure signal and the preprocessed simulated pressure signal. The correction module continuously corrects the preprocessed simulated pressure signal based on a preset recursive update equation, combined with dynamically determined target correction factors and gas molecule characteristic parameters, ensuring the real-time performance and effectiveness of the correction process. Therefore, this embodiment achieves dynamic, adaptive, and physical model-driven correction of the pressure signal. Consequently, this embodiment effectively improves the accuracy, stability, and long-term consistency of vacuum butterfly valve inlet pressure measurement, providing more reliable pressure data under complex conditions such as high vacuum, mixed gases, or large temperature fluctuations, thus laying the foundation for precise control of the vacuum system.

[0093] In some preferred embodiments, the recursive update equation is as follows:

[0094] ;

[0095] in, This represents the corrected analog pressure signal. This represents the preprocessed simulated pressure signal at time t. The target correction factor is represented at time t. This represents the collision frequency of gas molecules at time t. The diffusion coefficient at time t is represented. It represents the average kinetic energy at time t.

[0096] In some preferred embodiments, the pressure signal acquisition module 2 further includes a temperature compensation circuit, and the amplification circuit, low-pass filter circuit and temperature compensation circuit are connected in sequence. The preprocessing also includes temperature compensation processing.

[0097] The temperature compensation circuit in this embodiment is specifically designed to offset or reduce performance drift in electronic circuits caused by temperature changes. This circuit can be a feedback network based on temperature-sensitive elements such as thermistors or platinum resistance thermometers, adjusting circuit parameters by detecting temperature changes. Alternatively, it can be a digital temperature compensation module that corrects the signal based on temperature sensor RT data using a software algorithm. The core function of this temperature compensation circuit is to monitor the ambient temperature or the internal temperature of the circuit and generate a corresponding compensation signal to maintain the accuracy and stability of the pressure signal acquisition. In this embodiment, the amplification circuit, low-pass filter circuit, and temperature compensation circuit are connected sequentially, describing a specific order of signal processing. Specifically, the analog pressure signal first undergoes gain processing through the amplification circuit, then enters the low-pass filter circuit to remove high-frequency noise, and finally, the temperature compensation circuit performs temperature-related correction. This connection sequence ensures that the signal has undergone preliminary amplification and noise suppression before temperature compensation, avoiding interference with the original signal quality during the compensation process and making the compensation more effective. Because this embodiment performs temperature-related corrections on the analog pressure signal before converting it to a digital signal, it ensures that the influence of temperature on the analog pressure signal is minimized before digitization, thereby improving the accuracy and reliability of the subsequent digital pressure signal. The temperature compensation circuit in this embodiment preferably employs a differential compensation structure. This structure eliminates common-mode noise or temperature drift by comparing the difference between two signals (one temperature-affected signal and the other a reference signal). This structure can use a Wheatstone bridge 8 structure, where one arm of the Wheatstone bridge 8 contains a temperature-sensitive element, and a compensation signal is generated by balancing or unbalancing the Wheatstone bridge 8. Alternatively, a differential amplifier can be used to differentially amplify the output of the temperature-sensitive element with a reference voltage to generate a compensation voltage. This embodiment effectively suppresses common-mode interference and temperature-induced zero-point drift by employing a differential compensation structure in the temperature compensation circuit, thereby improving the accuracy and anti-interference capability of temperature compensation.

[0098] This embodiment introduces a temperature compensation circuit into the pressure signal acquisition module 2, and connects it sequentially with the amplification circuit and the low-pass filter circuit. This allows the analog pressure signal to undergo further temperature compensation processing after amplification and filtering, ensuring that the temperature drift of the analog pressure signal is effectively suppressed before digitization. This effectively improves the accuracy and stability of pressure signal acquisition. Therefore, this embodiment can ensure that the analog signal output by the pressure sensor can be accurately corrected in environments with large temperature fluctuations, providing a more reliable and stable data source for the subsequent analog-to-digital conversion module 3, gas molecule characteristic calculation unit 6, and pressure correction unit 7. This effectively improves the measurement accuracy and long-term operational stability of the vacuum butterfly valve inlet pressure data acquisition system.

[0099] In some preferred embodiments, the temperature compensation circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a first sliding rheostat RP1, a second sliding rheostat RP2, a third sliding rheostat RP3, a temperature sensor RT, a first capacitor C1, a second capacitor C2, an operational amplifier IC, and a Wheatstone bridge 8. One end of the first resistor R1 is connected to the output of the low-pass filter circuit, and the other end of the first resistor R1 is connected to one end of the first sliding rheostat RP1, one end of the temperature sensor RT, and one end of the third resistor R3. One end of the second resistor R2 is connected to the output of the operational amplifier IC and the other end of the temperature sensor RT, and the other end of the second resistor R2 is connected to the input of the analog-to-digital converter module 3. The other end of the third resistor R3 is connected to the ground terminal. One end of the fourth resistor R4... The other end of the first sliding rheostat RP1, one end of the fifth resistor R5, and the inverting input terminal of the operational amplifier IC are connected respectively. The other end of the fourth resistor R4 is connected to one end of the second sliding rheostat RP2 and one end of the third sliding rheostat RP3. The other end of the fifth resistor R5 is connected to one end of the seventh resistor R7 and one end of the first capacitor C1. One end of the sixth resistor R6 is connected to one end of the eighth resistor R8 and one end of the second capacitor C2. The other end of the sixth resistor R6 is connected to the non-inverting input terminal of the operational amplifier IC. The other ends of the first capacitor C1 and the second capacitor C2 are both connected to the ground terminal. The other end of the second sliding rheostat RP2 is connected to the output terminal of the low-pass filter circuit. The other end of the third sliding rheostat RP3 is connected to the ground terminal. The Wheatstone bridge 8 is connected to the output terminal of the low-pass filter circuit, the other end of the seventh resistor R7, the other end of the eighth resistor R8, and the ground terminal.

[0100] The Wheatstone bridge 8 in this embodiment is composed of Figure 2The circuit consists of RB1, RB2, RB3, and RB4. Through the above technical solution, this application provides a temperature compensation circuit with a specific structure, precise compensation, and strong adaptability. This circuit adopts a differential compensation structure, uses a temperature sensor RT to detect the ambient temperature in real time, and utilizes a Wheatstone bridge 8, a resistor network, and an operational amplifier IC to form a precise compensation loop. This design can effectively offset the zero-point drift and sensitivity attenuation of the pressure sensor output signal caused by changes in ambient temperature, thereby effectively improving the accuracy and stability of pressure signal acquisition in complex environments such as high temperatures or mixed gases. Compared with traditional compensation methods that rely on empirical formulas or static parameters, this solution achieves dynamic and real-time temperature compensation through a specific temperature compensation circuit, ensuring the quality of the pre-processed analog pressure signal. This provides more reliable basic data for the subsequent analog-to-digital conversion module 3 and gas molecule characteristic calculation unit 6, thereby effectively improving the overall performance and measurement reliability of the entire vacuum butterfly valve inlet pressure data acquisition system.

[0101] In some preferred embodiments, the analog-to-digital conversion module 3 employs a Sigma-Delta ADC chip and incorporates a multi-order digital filter. The Sigma-Delta ADC chip is an existing high-precision analog-to-digital converter. Its operating principle is based on oversampling and noise shaping techniques. Specifically, this chip samples the analog signal at high speed and pushes quantization noise to the high-frequency region. Then, a low-pass digital filter removes the high-frequency noise, thereby achieving high-resolution analog-to-digital conversion at a lower sampling rate. This chip effectively suppresses quantization noise and external electromagnetic interference, making it particularly suitable for scenarios requiring high-precision conversion of low-amplitude analog signals. Simultaneously, the analog-to-digital conversion module 3 incorporates a multi-order digital filter. This filter further processes the digital signal output from the Sigma-Delta ADC chip to remove high-frequency and quantization noise, improving signal purity and stability. The digital filter can be implemented through software algorithms or hardware logic. Higher order filters provide better filtering effects but also increase computational complexity and latency. Common digital filters include finite impulse response (FIR) filters and infinite impulse response (IIR) filters, which can be selected with different structures and parameters depending on specific application requirements. For example, FIR filters have linear phase characteristics and are suitable for applications with high phase requirements; IIR filters, on the other hand, can achieve steep frequency responses with lower orders.

[0102] This embodiment addresses the issues of signal conversion accuracy and stability in high vacuum or interference environments by optimizing the design of the analog-to-digital conversion module 3. Specifically, in the vacuum butterfly valve inlet pressure data acquisition system, after the pressure signal acquisition module 2 preprocesses the analog pressure signal, it inputs the analog signal to the analog-to-digital conversion module 3. The Sigma-Delta ADC chip in the analog-to-digital conversion module 3 utilizes its high resolution and oversampling characteristics to perform preliminary analog-to-digital conversion on the analog signal and effectively suppress quantization noise and external electromagnetic interference to ensure the initial accuracy of the digital pressure signal. Subsequently, the digital pressure signal is fed into the multi-stage digital filter built into the analog-to-digital conversion module 3. This multi-stage digital filter provides a steeper roll-off characteristic through its multi-stage filtering structure to efficiently filter out high-frequency noise and residual interference, thereby further improving the purity and smoothness of the digital pressure signal. Through this synergistic effect, the analog-to-digital conversion module 3 can provide a stable and high-precision digital pressure signal, providing reliable input data for the subsequent gas molecule characteristic calculation unit 6 and pressure correction unit 7, thereby enhancing the performance of the entire pressure data acquisition system.

[0103] In some preferred embodiments, the vacuum butterfly valve inlet pressure data acquisition system further includes an isolation drive unit, which includes an opto-isolation chip and an isolation power supply module. The isolation drive unit is used to electrically isolate the pressure signal acquisition module 2, analog-to-digital conversion module 3, temperature detection unit 4, gas type detection unit 5, gas molecule characteristic calculation unit 6, and pressure correction unit 7 from the actuator of the vacuum butterfly valve.

[0104] The isolation drive unit of this embodiment is a component used to provide electrical isolation between two circuits or systems. Its core function is to block the direct flow of current while allowing the transmission of signals or energy. This isolation can effectively prevent high voltage, transient noise, and ground loop currents from being transmitted from one system to another, thereby protecting sensitive circuits from damage or interference. The isolation drive unit of this embodiment can be implemented using various technologies, such as opto-isolation, magnetic isolation, or capacitive isolation. Specifically, opto-isolation transmits information through optical signals, magnetic isolation transmits information through magnetic fields, and capacitive isolation utilizes capacitive coupling to transmit high-frequency signals. The isolation drive unit in this embodiment specifically includes an opto-isolation chip and an isolation power supply module. The opto-isolation chip in this embodiment is an existing device that uses light as a medium to transmit electrical signals. It converts the electrical signal at the input end into an optical signal, and then converts the optical signal back into an electrical signal output through a photosensitive device, thereby achieving electrical isolation between the input and output ends. The opto-isolation chip can use a high-speed optocoupler (such as the HCPL-0600 series or 6N137). The isolation power supply module in this embodiment is a power supply that can provide electrical isolation between the input and output. This power supply ensures that there is no direct electrical connection between the output voltage and the input voltage through an internal transformer or other isolation technology, thereby effectively suppressing common-mode noise and ground loop current, and providing a clean and stable power supply for sensitive circuits. The isolation power supply module can use a transformer-isolated DC-DC converter (such as the RECOM RxxPxx series or Murata MGJ series) to provide independent and isolated power supplies for the pressure signal acquisition module 2, analog-to-digital conversion module 3, etc.

[0105] This embodiment effectively solves the problem of high voltage or strong electromagnetic interference generated by the actuator affecting sensitive measurement circuits during vacuum butterfly valve inlet pressure data acquisition by introducing an isolated drive unit. The actuator of the vacuum butterfly valve (e.g., a motor or solenoid valve) may generate significant electromagnetic noise or transient voltage during operation. If these interferences are directly coupled into the pressure data acquisition system, they will cause distortion of the analog pressure signal, errors in analog-to-digital conversion, and consequently affect the accuracy of calculating gas molecule characteristic parameters, even leading to calculation errors or instability in the entire system. The opto-isolation chip in the isolated drive unit transmits data via optical signals, completely severing the electrical connection on the signal path, thereby effectively blocking the propagation of common-mode noise and transient interference. Simultaneously, the isolated power supply module provides the data acquisition system with an independent power supply isolated from the actuator power supply, eliminating ground loop problems and ensuring a clean and stable power supply. In this way, key components such as the pressure signal acquisition module 2, analog-to-digital conversion module 3, temperature detection unit 4, gas type detection unit 5, gas molecule characteristic calculation unit 6, and pressure correction unit 7 can operate stably in an electrically isolated environment. The data they acquire and process are not affected by external electrical interference, thus ensuring the accuracy and reliability of pressure measurement and gas molecule characteristic parameter calculation.

[0106] In some preferred embodiments, the vacuum butterfly valve inlet pressure data acquisition system further includes a self-diagnostic module. The self-diagnostic module is used to trigger the gas molecule characteristic calculation unit 6 to recalculate the gas molecule characteristic parameters based on the preset reference pressure signal and the ambient temperature and gas type information at the current moment when the deviation between the simulated pressure signal at the current moment and the simulated pressure signal at the previous moment or the preset reference pressure signal is greater than a first preset threshold, the power supply voltage of the vacuum butterfly valve inlet pressure data acquisition system is outside the preset voltage range, or the rate of decrease of the power supply voltage is greater than a second preset threshold.

[0107] The self-diagnostic module of this embodiment determines whether there is an anomaly in the pressure signal by monitoring the deviation between the current analog pressure signal and the previous analog pressure signal or a preset reference pressure signal. This deviation is determined by comparing the digital pressure value output by the current analog-to-digital converter 3 with the previous sampling period or a pre-stored stable reference pressure value, calculating the absolute difference, and comparing it with a preset first threshold. If the absolute difference is greater than the first preset threshold, it indicates that the pressure signal may be drifting or abruptly changing, requiring intervention. The self-diagnostic module of this embodiment also monitors the power supply voltage of the vacuum butterfly valve inlet pressure data acquisition system. When the power supply voltage is outside a preset voltage range, it is considered that a power supply anomaly has occurred. Simultaneously, the self-diagnostic module of this embodiment obtains the rate of voltage drop by calculating the ratio of the voltage difference between adjacent sampling points to the sampling time interval. If the rate of voltage drop is greater than a second preset threshold, it indicates that a momentary voltage drop exists, affecting circuit stability.

[0108] When the self-diagnostic module detects any of the above-mentioned abnormal conditions (the deviation between the current simulated pressure signal and the previous simulated pressure signal or the preset reference pressure signal is greater than the first preset threshold, the power supply voltage of the vacuum butterfly valve inlet pressure data acquisition system is outside the preset voltage range or the rate of decrease of the power supply voltage is greater than the second preset threshold), the self-diagnostic module will trigger the gas molecule characteristic calculation unit 6. At this time, the gas molecule characteristic calculation unit 6 no longer uses the current pressure signal, which may be inaccurate, but instead uses a preset, known and stable reference pressure signal (e.g., the zero-point pressure measured in a calibration environment or a specific reference pressure), combined with the real-time acquired ambient temperature information and gas type information, to re-execute the calculation process of gas molecule characteristic parameters.

[0109] This embodiment introduces a self-diagnostic module that proactively triggers the gas molecule characteristic calculation unit 6 to recalculate gas molecule characteristic parameters when specific abnormal conditions are detected, thus addressing measurement instability issues. The self-diagnostic module continuously monitors the circuit status. When it detects a pressure signal deviation exceeding a threshold or an abnormal power supply voltage, indicating potential system drift or interference, triggering recalculation promptly corrects the error. Specifically, the self-diagnostic module identifies pressure surges or drift risks based on a deviation between the current simulated pressure signal and the previous timeframe or a preset reference exceeding a first preset threshold; it also identifies power supply instability based on a power supply voltage exceeding its range or a rate of decrease exceeding a second preset threshold. Under these conditions, the self-diagnostic module sends instructions to the gas molecule characteristic calculation unit 6, instructing it to recalculate the gas molecule characteristic parameters based on a preset reference pressure signal (as a reliable reference) combined with current ambient temperature and gas type information, ensuring accurate and reliable calculation input and preventing error accumulation. This proactive adjustment mechanism under abnormal conditions, rather than passive reliance, enhances the robustness of the entire vacuum butterfly valve inlet pressure data acquisition system. In this way, the calculation of gas molecule characteristic parameters can remain accurate even when there are fluctuations in the external environment or internal circuitry, thus ensuring the effectiveness of subsequent pressure correction and avoiding the accumulation of measurement errors.

[0110] As can be seen from the above, the vacuum butterfly valve inlet pressure data acquisition system provided in this application, by introducing a gas molecule characteristic calculation unit 6 and a pressure correction unit 7, realizes dynamic and accurate acquisition and correction of vacuum butterfly valve inlet pressure data. Since this application can dynamically calculate gas molecule characteristic parameters such as gas molecule collision frequency, diffusion coefficient and average kinetic energy based on the real-time acquired digital pressure signal, ambient temperature information and gas type information, and generate a corrected simulated pressure signal by correcting the pre-processed simulated pressure signal based on the gas molecule characteristic parameters, this application is equivalent to dynamically and adaptively correcting the pre-processed simulated pressure signal based on the microscopic physical properties of gas molecules. Therefore, this application can effectively solve the problems of nonlinear deviation and insufficient compensation strategy caused by changes in gas molecule behavior in high vacuum or mixed gas environments by traditional methods, thereby effectively improving the long-term consistency and accuracy of pressure measurement, and thus effectively improving the reliability and accuracy of vacuum control system.

[0111] In the embodiments provided in this application, it should be understood that relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0112] The above are merely embodiments of this application and are not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A vacuum butterfly valve inlet pressure data acquisition system, characterized in that, The vacuum butterfly valve inlet pressure data acquisition system includes: A pressure signal acquisition module is connected to the pressure sensor at the inlet of the vacuum butterfly valve. It includes an amplification circuit and a low-pass filter circuit for preprocessing the analog pressure signal acquired by the pressure sensor. The preprocessing includes signal amplification and filtering. An analog-to-digital conversion module, connected to the pressure signal acquisition module, is used to convert the preprocessed analog pressure signal into a digital pressure signal. Temperature detection unit, used to collect ambient temperature information; A gas type detection unit is used to collect information on the type of gas entering the vacuum butterfly valve; A gas molecule characteristic calculation unit, connected to the analog-to-digital conversion module, the temperature detection unit, and the gas type detection unit, is used to calculate gas molecule characteristic parameters based on the digital pressure signal, the ambient temperature information, and the gas type information; the gas molecule characteristic parameters include gas molecule collision frequency, diffusion coefficient, and average kinetic energy. The pressure correction unit is connected to the pressure signal acquisition module, the analog-to-digital conversion module, the gas molecule characteristic calculation unit, and the temperature detection unit, and is used to generate a corrected analog pressure signal based on the digital pressure signal, the gas molecule characteristic parameters, the ambient temperature information, and the preprocessed analog pressure signal. The pressure correction unit includes a pre-built virtual gas state model, a correction factor adaptive adjustment module, and a correction module. The input of the virtual gas state model is connected to the temperature detection unit, the gas type detection unit, and the gas molecule characteristic calculation unit. The correction factor adaptive adjustment module is connected to the output of the virtual gas state model and the pressure signal acquisition module. The correction module is connected to the pressure signal acquisition module, the gas molecule characteristic calculation unit, and the correction factor adaptive adjustment module. The virtual gas state model is used to generate a predicted pressure signal based on the ambient temperature information, the gas type information, and the gas molecule characteristic parameters. The correction factor adaptive adjustment module is used to determine a target correction factor based on the deviation between the predicted pressure signal and the pre-processed simulated pressure signal. The correction module is used to generate a corrected simulated pressure signal based on a preset recursive update equation, the target correction factor, the gas molecule characteristic parameters, and the pre-processed simulated pressure signal.

2. The vacuum butterfly valve inlet pressure data acquisition system according to claim 1, characterized in that, The process by which the gas molecule characteristic calculation unit calculates gas molecule characteristic parameters based on the digital pressure signal, the ambient temperature information, and the gas type information includes: A1. Obtain the gas molecule diameter and gas molecule mass corresponding to the gas type information; A2. Calculate the mean free path of the gas molecules based on the ambient temperature information, the gas molecule diameter, and the digital pressure signal; A3. Calculate the average velocity of gas molecules based on the ambient temperature information and the mass of gas molecules; A4. Calculate the collision frequency of gas molecules based on the average velocity of the gas molecules and the mean free path of the gas molecules; A5. Calculate the average kinetic energy based on the ambient temperature information; A6. Calculate the diffusion coefficient based on the average velocity of the gas molecules and the mean free path of the gas molecules.

3. The vacuum butterfly valve inlet pressure data acquisition system according to claim 2, characterized in that, The formula for calculating the mean free path of the gas molecules is as follows: ； in, The mean free path of gas molecules is represented by , k represents the Boltzmann constant, T represents the ambient temperature information, π represents pi, d represents the diameter of gas molecules, and P represents the digital pressure signal. The formula for calculating the average velocity of the gas molecules is as follows: ； in, represents the average velocity of gas molecules, and m represents the mass of a gas molecule; The formula for calculating the collision frequency of gas molecules is as follows: ； Among them, f c Indicates the collision frequency of gas molecules; The formula for calculating the average kinetic energy is as follows: ； in, This represents the average kinetic energy. The diffusion coefficient is calculated using the following formula: ； in, This represents the diffusion coefficient.

4. The vacuum butterfly valve inlet pressure data acquisition system according to claim 1, characterized in that, The recursive update equation is shown below: ； in, This indicates a correction to the analog pressure signal. This represents the preprocessed simulated pressure signal at time t. The target correction factor is represented at time t. This represents the collision frequency of gas molecules at time t. The diffusion coefficient at time t is represented. It represents the average kinetic energy at time t.

5. The vacuum butterfly valve inlet pressure data acquisition system according to claim 1, characterized in that, The pressure signal acquisition module also includes a temperature compensation circuit. The amplification circuit, the low-pass filter circuit and the temperature compensation circuit are connected in sequence. The preprocessing also includes temperature compensation processing.

6. The vacuum butterfly valve inlet pressure data acquisition system according to claim 5, characterized in that, The temperature compensation circuit includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a first sliding rheostat, a second sliding rheostat, a third sliding rheostat, a temperature sensor, a first capacitor, a second capacitor, an operational amplifier, and a Wheatstone bridge. One end of the first resistor is connected to the output of the low-pass filter circuit, and the other end of the first resistor is connected to one end of the first sliding rheostat, one end of the temperature sensor, and one end of the third resistor. One end of the second resistor is connected to the output of the operational amplifier and the other end of the temperature sensor, and the other end of the second resistor is connected to the input of the analog-to-digital converter module. The other end of the third resistor is connected to ground. One end of the fourth resistor is connected to the other end of the first sliding rheostat and the other end of the fifth resistor. One end of the fourth resistor is connected to the inverting input terminal of the operational amplifier. The other end of the fourth resistor is connected to one end of the second sliding rheostat and one end of the third sliding rheostat. The other end of the fifth resistor is connected to one end of the seventh resistor and one end of the first capacitor. One end of the sixth resistor is connected to one end of the eighth resistor and one end of the second capacitor. The other end of the sixth resistor is connected to the non-inverting input terminal of the operational amplifier. The other ends of the first capacitor and the second capacitor are both connected to the ground terminal. The other end of the second sliding rheostat is connected to the output terminal of the low-pass filter circuit. The other end of the third sliding rheostat is connected to the ground terminal. The Wheatstone bridge is connected to the output terminal of the low-pass filter circuit, the other end of the seventh resistor, the other end of the eighth resistor, and the ground terminal.

7. The vacuum butterfly valve inlet pressure data acquisition system according to claim 1, characterized in that, The analog-to-digital conversion module uses a Sigma-Delta ADC chip and is equipped with a multi-stage digital filter.

8. The vacuum butterfly valve inlet pressure data acquisition system according to claim 1, characterized in that, The vacuum butterfly valve inlet pressure data acquisition system also includes an isolation drive unit, which includes an opto-isolation chip and an isolation power supply module. The isolation drive unit is used to electrically isolate the pressure signal acquisition module, the analog-to-digital conversion module, the temperature detection unit, the gas type detection unit, the gas molecule characteristic calculation unit, and the pressure correction unit from the actuator of the vacuum butterfly valve.

9. The vacuum butterfly valve inlet pressure data acquisition system according to claim 1, characterized in that, The vacuum butterfly valve inlet pressure data acquisition system also includes a self-diagnostic module. The self-diagnostic module is used to trigger the gas molecule characteristic calculation unit to recalculate the gas molecule characteristic parameters based on the preset reference pressure signal and the current ambient temperature and gas type information when the deviation between the simulated pressure signal at the current moment and the simulated pressure signal at the previous moment or the preset reference pressure signal is greater than a first preset threshold, the power supply voltage of the vacuum butterfly valve inlet pressure data acquisition system is outside the preset voltage range, or the rate of decrease of the power supply voltage is greater than a second preset threshold.

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