Secondary flow correction method, system and equipment for mass flow controller

Abstract

The invention provides a secondary flow correction method, system and device for a mass flow controller, and relates to the technical field of fluid measurement and control, and the method comprises the steps: obtaining an actual gas flow value and a theoretical gas flow control value corresponding to each flow value set point in a target mass flow controller, the target mass flow controller is a mass flow controller calibrated through preset calibration gas; the actual gas flow value represents a gas flow value obtained by measuring gas passing through a flow value set point in the target mass flow controller at present; according to the actual gas flow value and the theoretical gas flow control value, determining a secondary correction coefficient of each flow value set point; and based on each secondary correction coefficient, correcting a preset gas flow control value in a corresponding flow value range in the target mass flow controller. According to the invention, the flow deviation of the MFC under different gases and set points is reduced.

Description

Technical Field

[0001] The present invention relates to the field of fluid measurement and control technology, and in particular to a secondary flow correction method, system and equipment for a mass flow controller. Background Art

[0002] A mass flow controller (MFC) is a device used to precisely control gas flow. During the calibration process of an MFC, one or two specific gases (such as nitrogen) are typically used as calibration gases.

[0003] After calibration based on these specific gases, the MFC generates quintic function parameters. When using other gases, the MFC corrects these parameters using gas conversion coefficients. However, these parameters still cannot fully adapt to the non-specific gas at a specific set point. As a result, in actual applications, when the same MFC is used for gas type conversion or range adjustment, the actual gas flow at a certain set point may deviate from the set value.

[0004] Therefore, there is an urgent need for a secondary flow correction method, system and device for a mass flow controller to solve the above problems. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a secondary flow correction method, system and device for a mass flow controller.

[0006] The present invention provides a secondary flow correction method for a mass flow controller, comprising: Obtaining actual gas flow values ​​and theoretical gas flow control values ​​corresponding to each flow value set point in a target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; the actual gas flow value represents a gas flow value currently measured by the gas passing through the flow value set point in the target mass flow controller; Determining a secondary correction coefficient for each flow value set point based on the actual gas flow value and the theoretical gas flow control value; Based on each of the quadratic correction coefficients, a preset gas flow control value within a corresponding flow value range in the target mass flow controller is corrected.

[0007] According to a secondary flow correction method for a mass flow controller provided by the present invention, before obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller, the method further includes: When it is determined that the gas type of the gas passing through the target mass flow controller changes, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

[0008] According to a secondary flow correction method for a mass flow controller provided by the present invention, the method further includes: When it is determined that the measurement range of the target mass flow controller is converted, or when the accumulated operating time of the target mass flow controller reaches a preset threshold, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

[0009] According to a secondary flow correction method for a mass flow controller provided by the present invention, determining a secondary correction coefficient for each flow value set point based on the actual gas flow value and the theoretical gas flow control value includes: The quadratic correction coefficient of each of the flow value set points is determined based on a ratio between the actual gas flow value and the preset gas flow control value.

[0010] According to a secondary flow correction method for a mass flow controller provided by the present invention, the preset gas flow control value within the corresponding flow value range in the target mass flow controller is corrected based on each of the secondary correction coefficients, including: determining a first target correction coefficient and a second target correction coefficient, wherein the first target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value as a lower limit value within the flow value range; and the second target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value as an upper limit value within the flow value range; interpolating the first target correction coefficient and the second target correction coefficient based on the position of the preset gas flow control value within the flow value range to obtain a third target correction coefficient; The preset gas flow control value is corrected according to the third target correction coefficient.

[0011] According to a secondary flow correction method for a mass flow controller provided by the present invention, the method further includes: Adjusting each of the flow value set points according to the set point adjustment instruction information to obtain each adjusted flow value set point; The step of obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller includes: The actual gas flow value and the theoretical gas flow control value corresponding to each of the adjusted flow value set points in the target mass flow controller are obtained.

[0012] The present invention also provides a secondary flow correction system for a mass flow controller, comprising: a secondary calibration acquisition module, configured to obtain actual gas flow values ​​and theoretical gas flow control values ​​corresponding to respective flow value set points in a target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; and the actual gas flow values ​​represent gas flow values ​​currently measured through the flow value set points in the target mass flow controller; a calculation module, configured to determine a secondary correction coefficient for each flow value set point based on the actual gas flow value and the theoretical gas flow control value; The secondary flow correction module is used to correct the preset gas flow control value within the corresponding flow value range in the target mass flow controller based on each of the secondary correction coefficients.

[0013] According to a secondary flow correction system for a mass flow controller provided by the present invention, the system further includes: The data acquisition module is used to collect the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller when it is determined that the gas type of the gas passing through the target mass flow controller has changed.

[0014] According to a secondary flow correction system for a mass flow controller provided by the present invention, the data acquisition module is further used for: When it is determined that the measurement range of the target mass flow controller is converted, or when the accumulated operating time of the target mass flow controller reaches a preset threshold, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

[0015] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the secondary flow correction method for a mass flow controller as described above is implemented.

[0016] The present invention provides a secondary flow correction method, system, and device for a mass flow controller. The method obtains the actual gas flow value and theoretical gas flow control value corresponding to each flow set point of a target MFC that has been calibrated with a preset calibration gas; then, based on the actual gas flow value and the theoretical gas flow control value, a secondary correction coefficient for each set point is determined; finally, these secondary correction coefficients are used to correct the preset gas flow control value within the corresponding flow value range of the target MFC, thereby reducing the flow deviation of the same MFC under different gases and set points. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A schematic flow chart of a secondary flow correction method for a mass flow controller provided by the present invention; Figure 2 A schematic structural diagram of a secondary flow correction system for a mass flow controller provided by the present invention; Figure 3 This is a schematic structural diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0019] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0020] Even with universal gas coefficient conversion, it's difficult to guarantee the accuracy requirements of the same MFC at any set point for different gases and ranges after calibration using a single gas, due to the uncertainty inherent in actual use environments and complex processes. This invention optimizes the MFC's parameters based on the actual gas and range used, automatically adjusting the current correction coefficient to achieve higher accuracy for the actual gas in real-world scenarios.

[0021] Figure 1 A schematic flow chart of a secondary flow correction method for a mass flow controller provided by the present invention is shown in FIG. Figure 1As shown, the present invention provides a secondary flow correction method for a mass flow controller, comprising: Step 101: Obtain actual gas flow values ​​and theoretical gas flow control values ​​corresponding to each flow value set point in a target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; the actual gas flow value represents the gas flow value obtained by measuring the gas currently passing through the flow value set point in the target mass flow controller.

[0022] During the standard MFC calibration process, the operator first sets the flow rate. The operator pre-sets a series of flow rates based on the MFC's performance range and calibration requirements. For example, for an MFC with a maximum full-scale range of 100 sccm (standard cubic centimeters per minute), the operator can set flow rates of 10 sccm, 20 sccm, 30 sccm, and so on, to 100 sccm. These different setpoints allow the MFC to control gas flow according to varying flow requirements, providing a diverse data sample for subsequent calibration.

[0023] Furthermore, while the MFC controls the gas flow according to the set flow value, a reference flow meter is required to accurately record the actual flow value under the current control gas conditions. The reference flow meter is a precisely calibrated flow measurement device with high accuracy and reliability that can provide very accurate gas flow measurement results. For example, when the MFC is set to 20 sccm, the reference flow meter may measure the actual gas flow rate as 19.8 sccm. In this way, for each set flow value of the MFC, a corresponding actual flow measurement value can be obtained, providing key actual data support for subsequent data analysis and calibration.

[0024] By setting flow values ​​and measuring using a reference flowmeter as described above, a series of data sets are generated. These data sets include multiple MFC set values ​​and the corresponding actual flow values, and these data cover the maximum full-scale range of the MFC. For example, for the MFC with a maximum full-scale range of 100 sccm mentioned in the above embodiment, multiple data sets such as (10 sccm, 9.8 sccm), (20 sccm, 19.8 sccm), (30 sccm, 29.5 sccm), ..., (100 sccm, 99.5 sccm) can be obtained. These multiple data sets are an important basis for MFC calibration, reflecting the relationship between the MFC set values ​​and the actual flow rates.

[0025] Ideally, the MFC setpoint is the theoretical gas flow rate. However, in practice, due to factors such as MFC manufacturing tolerances and sensor characteristics, there is often a discrepancy between the setpoint and the actual flow rate. Furthermore, multiple sets of acquired setpoints (which serve as theoretical flow rates) and the corresponding measured flow rates are processed. This invention uses polynomial fitting to find a suitable polynomial curve equation that accurately describes the relationship between the theoretical flow rate (setpoint) and the electrical signal generated by the actual flow through the sensor.

[0026] For example, suppose multiple sets of data (setpoint x and actual flow rate value y) exhibit a specific curve trend. Polynomial fitting can yield a curve equation. This curve equation reflects the relationship between the theoretical flow rate and the actual electrical signal. Because the MFC uses a sensor to detect gas flow and convert it into an electrical signal for control and measurement, this equation effectively establishes an accurate correspondence between the MFC setpoint (theoretical flow rate) and the sensor's electrical signal.

[0027] After obtaining the curve equation through the above polynomial fitting, the curve equation is stored in the MFC's internal memory. During subsequent actual use, when the MFC receives a set flow rate value, it converts this set value into a corresponding electrical signal control instruction based on the stored curve equation and sends it to the sensor and control system. At the same time, when the sensor detects the actual gas flow and generates an electrical signal, the MFC can also reverse-infer the electrical signal into the actual flow value based on the curve equation, thereby achieving more accurate gas flow control and measurement, allowing the MFC to operate according to the accurate relationship after calibration, and improving the accuracy and reliability of flow control.

[0028] Furthermore, after completing the conventional calibration process, the MFC calibrated with the preset calibration gas is designated the target MFC. The actual gas flow values ​​and theoretical gas flow control values ​​corresponding to each flow setpoint in the target MFC are then acquired. Specifically, building on the existing conventional calibration (using calibration gas), the target MFC is again subjected to multiple setpoint actual gas flow acquisition using gases (other than the calibration gas) that will be used in actual use scenarios. This is known as secondary flow acquisition.

[0029] Among them, the actual gas flow value refers to the gas flow value obtained through actual measurement when the gas flows through a specific flow value set point in the target MFC. For example, the gas flow passing through the set point is measured using a measurement tool such as an actual gas standard meter to obtain this actual value. The theoretical gas flow control value is the gas flow value that should theoretically be controlled at the corresponding flow value set point based on the setting of the target MFC. For example, when the set point is set to 13%, the target MFC should theoretically control the gas flow to reach a certain specific ratio (assuming that the theoretical value is the flow ratio corresponding to the set point value, such as the theoretical flow ratio corresponding to 13%). This theoretical flow control value is the theoretical gas flow control value.

[0030] Step 102, determining a secondary correction coefficient for each flow value set point based on the actual gas flow value and the theoretical gas flow control value; In the present invention, the secondary correction coefficient is determined by calculating the actual gas flow rate value against the theoretical gas flow rate control value. Specifically, the calculation is: divide the actual gas flow rate value by the theoretical gas flow rate control value. For example, at a set point of 13%, if the target MFC output value (which can be understood as a reflection of the theoretical gas flow rate control value) is 13.0% (assuming the output value is consistent with the theoretical value for the sake of explanation), and the actual gas flow rate measured by the actual gas standard meter is 10.5%, then the secondary correction coefficient A1 for the 13% set point is equal to 10.5 divided by 13.0, i.e., A1 = 10.5 / 13.0 = 0.81. Similarly, at a set point of 27%, if the target MFC output value is 27.0% and the actual gas standard meter measured value is 20.8%, then the secondary correction coefficient A2 for the 27% set point is 20.8 / 27.0 = 0.77. Using this calculation method, a corresponding secondary correction coefficient can be derived for each flow rate set point. In addition, the set point is set according to actual usage requirements. For the coefficients between the set points, the present invention can calculate the coefficients of the set points at both ends through certain interpolation methods, thereby obtaining the complete secondary correction coefficients corresponding to the set points of each flow value.

[0031] Step 103 : Correcting a preset gas flow control value within a corresponding flow value range in the target mass flow controller based on each of the quadratic correction coefficients.

[0032] In the present invention, after obtaining the secondary correction coefficients for each flow value set point, the preset gas flow control value within the corresponding flow value range in the target MFC is corrected based on these secondary correction coefficients.

[0033] Specifically, the multi-point flow correction coefficients collected for the second time (i.e., the secondary correction coefficients) are written into the memory of the target MFC. When the target MFC is set to any flow point, it can automatically search and switch to a matching flow correction coefficient from the memory based on the current output flow value range. For example, when the target MFC is set to a flow point between 13% and 27%, the target MFC will select the secondary correction coefficient A1 corresponding to the 13% set point and the secondary correction coefficient A2 corresponding to the 27% set point based on the range of this flow point, calculate the secondary correction coefficients for the corresponding points in the range, and then use this calculated secondary correction coefficient to correct the preset gas flow control value, so that the gas flow output by the target MFC is closer to the actual demand, improve the accuracy of flow control, and ensure that when different gases are actually used, the target MFC can control the gas flow more accurately.

[0034] The secondary flow correction method for a mass flow controller provided by the present invention obtains the actual gas flow value and theoretical gas flow control value corresponding to each flow set point of a target MFC that has been calibrated with a preset calibration gas; then, based on the actual gas flow value and the theoretical gas flow control value, a secondary correction coefficient for each set point is determined; finally, these secondary correction coefficients are used to correct the preset gas flow control value within the corresponding flow value range of the target MFC, thereby reducing the flow deviation of the same MFC under different gases and set points.

[0035] Based on the above embodiment, before obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller, the method further includes: When it is determined that the gas type of the gas passing through the target mass flow controller changes, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

[0036] In the present invention, in actual application scenarios, the target MFC may be used to control multiple different types of gases, such as switching from controlling nitrogen to controlling oxygen, or from controlling argon to controlling helium, etc.

[0037] In the present invention, a change in gas type is determined by certain detection means or operator setting changes. The detection means may include gas sensor analysis and identification of gas composition, or switching instructions based on the gas supply system in the process flow.

[0038] In the present invention, the target MFC typically has multiple preset flow rate setpoints. These setpoints are determined based on actual application requirements and the controller's performance range. For example, an MFC with a maximum full-scale range of 100 sccm (standard cubic centimeters per minute) may have multiple flow rate setpoints, such as 10 sccm, 20 sccm, 30 sccm, and so on. These setpoints cover the various flow rate ranges within which the controller can operate and comprehensively reflect the controller's performance under different operating conditions.

[0039] When gas passes through the target MFC and reaches a specific flow rate setpoint, a precise measuring device (such as a reference flowmeter) is required to measure the actual gas flow rate. This actual gas flow rate reflects the actual flow rate of the gas under the current conditions (including gas type, temperature, and pressure). For example, when the target MFC is set to a setpoint of 20 sccm, the actual gas flow rate measured by the reference flowmeter may be 19.8 sccm. This value is affected by the gas type, and the actual flow rate of different gases at the same setpoint may vary.

[0040] The theoretical gas flow control value is the expected gas flow value based on the target MFC settings and ideal operating conditions. Ideally, when the target MFC is set to a certain flow setpoint, the gas should theoretically be controlled to flow at that setpoint. For example, when the setpoint is 20 sccm, the theoretical gas flow control value is 20 sccm. However, in practice, due to various factors (such as gas type and sensor errors), the actual gas flow value often deviates from the theoretical gas flow control value.

[0041] By collecting actual gas flow values ​​and theoretical gas flow control values ​​corresponding to various flow setpoints for different gas types, the present invention can compare and analyze the differences between the actual and theoretical values. This difference can reflect the control accuracy and performance of the target MFC under different gas types. For example, if the actual flow values ​​of a particular gas at multiple setpoints deviate significantly from the theoretical value, this indicates that the target MFC may have problems controlling that gas and requires further adjustment or calibration.

[0042] Because different gases have different physical properties (such as density and viscosity), these properties affect gas flow and measurement in the MFC. The collected actual gas flow values ​​and theoretical gas flow control value data provide a basis for subsequent calibration and compensation work. Based on this data, calibration coefficients or compensation algorithms can be calculated for different gas types and flow set points, thereby modifying the MFC output to achieve more accurate flow control for different gas types.

[0043] By collecting relevant data when gas types change, this invention enables MFCs to better adapt to diverse application scenarios. For example, in semiconductor manufacturing, different process steps may require the use of different gases. By collecting and analyzing data, the controller can quickly and accurately adjust control parameters when switching gases, ensuring process stability and product quality.

[0044] Based on the above embodiment, the method further includes: When it is determined that the measurement range of the target mass flow controller is converted, or when the accumulated operating time of the target mass flow controller reaches a preset threshold, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

[0045] In the present invention, MFCs typically have different measurement ranges to accommodate different scales of gas flow measurement. For example, an MFC may have both a small range of 0 to 10 sccm (standard cubic centimeters per minute) and a large range of 0 to 100 sccm. Measurement range conversion occurs when the MFC is switched from a small range to a large range, or vice versa, depending on the needs of the actual application scenario.

[0046] Range conversion affects the measurement accuracy and control performance of an MFC. Sensor sensitivity, signal processing methods, and other factors may vary across different ranges. For example, at low ranges, the sensor is more sensitive to small flow changes; at high ranges, the sensor must be able to withstand a wider flow range, potentially reducing its accuracy. Therefore, after a range conversion, re-data collection is necessary to evaluate the performance of the target MFC in the new range.

[0047] In the present invention, a preset threshold for the cumulative operating time of the target MFC can also be set. This threshold is determined based on factors such as the target MFC's performance characteristics, operating environment, and maintenance requirements. For example, considering that the target MFC's sensors may age and drift over time, affecting measurement accuracy, the preset threshold can be set to 1000 hours. When the target MFC's cumulative operating time reaches or exceeds this preset value, data collection is triggered.

[0048] As the target MFC's operating time increases, its components gradually wear and age. For example, sensors may experience long-term effects from factors such as gas shock and temperature fluctuations, causing their output signals to drift and resulting in inaccurate measurements. Control valves may also wear out from frequent opening and closing operations, affecting their control accuracy of gas flow. Therefore, when the accumulated operating time reaches a preset threshold, data collection can promptly identify changes in controller performance, providing a basis for subsequent maintenance and calibration.

[0049] Based on the above embodiment, the method of determining the secondary correction coefficient of each flow value set point according to the actual gas flow value and the theoretical gas flow control value includes: The quadratic correction coefficient of each of the flow value set points is determined based on a ratio between the actual gas flow value and the preset gas flow control value.

[0050] In this disclosure, the actual gas flow rate is measured using precise measurement equipment (such as a high-precision reference flowmeter) under actual operating conditions. It represents the actual flow rate of gas through the target MFC, reflecting the actual gas flow under current environmental conditions (such as temperature, pressure, gas type, etc.) and the actual operating conditions of the target MFC. For example, in a chemical production process, a reference flowmeter was used to measure the actual hydrogen flow rate through the MFC to be 50 standard liters per minute.

[0051] The preset gas flow control value is a desired gas flow value set in advance on the target MFC based on production process requirements or experimental design. It is used to guide the target MFC in controlling gas flow. For example, based on reaction conditions, the preset hydrogen flow control value is 52 standard liters / minute.

[0052] In the present invention, the actual gas flow rate is divided by the preset gas flow rate control value, and the result is the ratio between the two. This ratio reflects the degree of deviation between the actual flow rate and the preset flow rate. If the ratio is equal to 1, it means that the actual flow rate is exactly the same as the preset flow rate; if the ratio is less than 1, it means that the actual flow rate is less than the preset flow rate; and if the ratio is greater than 1, it means that the actual flow rate is greater than the preset flow rate.

[0053] The secondary correction factor is used to further adjust and optimize the initial control parameters of the target MFC. It corrects the target MFC's output based on the actual measured flow deviation, bringing the actual gas flow closer to the preset gas flow control value after correction, thereby improving flow control accuracy. Each flow setpoint has its own independent secondary correction factor because the target MFC's performance and control error may vary at different flow setpoints.

[0054] In the present invention, the actual gas flow rate and the corresponding preset gas flow control value are measured and recorded at different flow rate set points. For example, for a target MFC with a range of 0 to 100 standard liters per minute, multiple flow rate set points such as 10, 20, 30, ..., and 100 standard liters per minute can be selected for measurement. For each flow rate set point, the ratio between the actual gas flow rate and the preset gas flow control value is calculated according to the ratio calculation method described above. Furthermore, using the secondary correction coefficient, the control parameters of the target MFC can be fine-tuned to reduce the deviation between the actual gas flow rate and the preset gas flow rate, thereby improving the accuracy of flow control and meeting the strict gas flow requirements of the production process.

[0055] In practical applications, changes in environmental conditions (such as temperature and pressure) and gas type may affect MFC performance. By determining the secondary correction coefficient at different flow rate set points, the MFC can better adapt to these changes and ensure accurate flow control under various operating conditions. In this invention, the secondary correction coefficient can be regularly determined and updated, helping to promptly identify MFC performance changes and potential problems, providing a basis for equipment maintenance and calibration, and thus optimizing overall equipment performance.

[0056] On the basis of the above embodiment, the correction of the preset gas flow control value within the corresponding flow value range in the target mass flow controller based on each of the quadratic correction coefficients includes: determining a first target correction coefficient and a second target correction coefficient, wherein the first target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value as a lower limit value within the flow value range; and the second target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value as an upper limit value within the flow value range; interpolating the first target correction coefficient and the second target correction coefficient based on the position of the preset gas flow control value within the flow value range to obtain a third target correction coefficient; The preset gas flow control value is corrected according to the third target correction coefficient.

[0057] In the present invention, the theoretical gas flow control value is a predetermined desired gas flow rate value based on production process requirements, experimental design, or other needs. It serves as the target reference value for flow control. For example, in semiconductor manufacturing processes, the theoretical flow control value of a certain gas is set at 100 sccm (standard cubic centimeters per minute) to precisely control chemical reactions.

[0058] The secondary correction coefficient, calculated using the above-described embodiment, is used to further adjust and optimize the initial control parameters of the MFC. The flow rate range refers to the interval within which the MFC operates normally and controls gas flow, with a lower limit and an upper limit. The first target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value serving as the lower limit within the flow rate range. For example, the secondary correction coefficient obtained through measurement and calculation for the theoretical gas flow control value corresponding to the lower limit of 10 sccm is the first target correction coefficient. Assuming that at a set point of 10 sccm, the actual flow rate is 9 sccm, the preset flow rate is 10 sccm, and the ratio is 0.9, then the secondary correction coefficient (first target correction coefficient) is 1 / 0.9 ≈ 1.11. The second target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value serving as the upper limit within the flow rate range. For example, the secondary correction coefficient obtained through measurement and calculation for the theoretical gas flow control value corresponding to the upper limit of 20 sccm is the second target correction coefficient.

[0059] In the present invention, the correction coefficients corresponding to the lower limit and upper limit of the flow value range are known (the first target correction coefficient and the second target correction coefficient). When the preset gas flow control value is within this flow value range, the correction coefficient corresponding to the preset value (the third target correction coefficient) can be estimated by interpolation.

[0060] Furthermore, the third target correction coefficient is multiplied by the preset gas flow control value to obtain a corrected gas flow control value. The present invention utilizes interpolation processing to obtain a correction coefficient that better matches the current preset flow position, thereby adjusting the preset gas flow control value to be closer to the actual desired flow value. By considering the correction requirements at different positions within the flow value range, the control errors that may be caused by using only a single correction coefficient are avoided, thereby improving the accuracy and stability of flow control.

[0061] Based on the above embodiment, the method further includes: Adjusting each of the flow value set points according to the set point adjustment instruction information to obtain each adjusted flow value set point; The step of obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller includes: The actual gas flow value and the theoretical gas flow control value corresponding to each of the adjusted flow value set points in the target mass flow controller are obtained.

[0062] In the present invention, setpoint adjustment command information can be obtained by a control system or other related equipment and is used to instruct the modification of the flow rate setpoint of a target MFC. The command information may include information such as the direction of the adjustment (increase or decrease the flow rate) and the magnitude of the adjustment (the specific flow rate increase or decrease value or ratio). For example, in a chemical production process, due to changes in reaction conditions, a command may be issued through the control panel to adjust the flow rate setpoint of a specific MFC from 50 liters / minute to 60 liters / minute.

[0063] Furthermore, the original flow rate set point is modified according to the set point adjustment instruction information to obtain an adjusted flow rate set point. The adjusted flow rate set point is then stored in the MFC's memory, and the relevant display interface is updated so that the operator can understand the current setting in real time. In the present invention, the actual gas flow value and theoretical gas flow control value corresponding to the adjusted flow rate set point are obtained, providing an accurate data basis for subsequent flow control accuracy assessment, error analysis, and correction coefficient calculation, allowing appropriate optimization and adjustment measures to be taken, thereby improving the performance and reliability of the entire flow control system.

[0064] The secondary flow correction system for a mass flow controller provided by the present invention is described below. The secondary flow correction system for a mass flow controller described below and the secondary flow correction method for a mass flow controller described above can refer to each other.

[0065] Figure 2 The schematic diagram of the structure of the secondary flow correction system for the mass flow controller provided by the present invention is as follows: Figure 2 As shown, the present invention provides a secondary flow correction system for a mass flow controller, including a secondary correction acquisition module 201, a calculation module 202 and a secondary flow correction module 203, wherein the secondary correction acquisition module 201 is used to obtain the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated by a preset calibration gas; the actual gas flow value represents the gas flow value obtained by measuring the gas currently passing through the flow value set point in the target mass flow controller; the calculation module 202 is used to determine the secondary correction coefficient of each flow value set point according to the actual gas flow value and the theoretical gas flow control value; the secondary flow correction module 203 is used to correct the preset gas flow control value within the corresponding flow value range in the target mass flow controller based on each of the secondary correction coefficients.

[0066] The secondary flow correction system for a mass flow controller provided by the present invention obtains the actual gas flow value and theoretical gas flow control value corresponding to each flow set point of a target MFC that has been calibrated with a preset calibration gas; then, based on the actual gas flow value and the theoretical gas flow control value, a secondary correction coefficient for each set point is determined; finally, these secondary correction coefficients are used to correct the preset gas flow control value within the corresponding flow value range of the target MFC, thereby reducing the flow deviation of the same MFC under different gases and set points.

[0067] Based on the above embodiment, the system also includes a data acquisition module for collecting the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller when it is determined that the gas type of the gas passing through the target mass flow controller has changed.

[0068] Based on the above embodiment, the data acquisition module is further used to: when it is determined that the measurement range of the target mass flow controller has been converted, or the cumulative operating time of the target mass flow controller has reached a preset threshold, collect the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller.

[0069] The system provided in the embodiment of the present invention is used to execute the above-mentioned method embodiments. Please refer to the above-mentioned embodiments for the specific process and detailed content, which will not be repeated here.

[0070] Figure 3 A schematic diagram of the structure of the electronic device provided by the present invention, such as Figure 3As shown, the electronic device may include: a processor 301, a communications interface 302, a memory 303, and a communications bus 304, wherein the processor 301, the communications interface 302, and the memory 303 communicate with each other via the communications bus 304. The processor 301 may call logic instructions in the memory 303 to execute a secondary flow correction method for a mass flow controller, the method comprising: obtaining actual gas flow values ​​and theoretical gas flow control values ​​corresponding to respective flow value set points in a target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; the actual gas flow values ​​represent gas flow values ​​currently measured at the flow value set points in the target mass flow controller; determining secondary correction coefficients for respective flow value set points based on the actual gas flow values ​​and the theoretical gas flow control values; and correcting the preset gas flow control values ​​within the corresponding flow value range in the target mass flow controller based on the respective secondary correction coefficients.

[0071] Furthermore, the logic instructions in the aforementioned memory 303 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0072] On the other hand, the present invention also provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute the secondary flow correction method for a mass flow controller provided by the above methods, the method including: obtaining the actual gas flow value and theoretical gas flow control value corresponding to each flow value setting point in the target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated with a preset calibration gas; the actual gas flow value represents the gas flow value obtained by measuring the gas currently passing through the flow value setting point in the target mass flow controller; based on the actual gas flow value and the theoretical gas flow control value, determining the secondary correction coefficient of each flow value setting point; based on each of the secondary correction coefficients, correcting the preset gas flow control value within the corresponding flow value range in the target mass flow controller.

[0073] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the secondary flow correction method for a mass flow controller provided in the above-mentioned embodiments, the method comprising: obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value setting point in the target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; the actual gas flow value represents the gas flow value obtained by measuring the gas currently passing through the flow value setting point in the target mass flow controller; determining the secondary correction coefficient for each flow value setting point based on the actual gas flow value and the theoretical gas flow control value; and correcting the preset gas flow control value within the corresponding flow value range in the target mass flow controller based on each of the secondary correction coefficients.

[0074] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0075] Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented using software plus a necessary general-purpose hardware platform, or of course, hardware. Based on this understanding, the essence of the above technical solution, or the portion that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, or an optical disk, and includes a number of instructions for causing a computer device (such as a personal computer, server, or network device) to execute the methods described in each embodiment or certain portions of the embodiments.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A secondary flow calibration method for a mass flow controller, characterized in that: include: Obtaining actual gas flow values ​​and theoretical gas flow control values ​​corresponding to each flow value set point in a target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; the actual gas flow value represents a gas flow value currently measured by the gas passing through the flow value set point in the target mass flow controller; Determining a secondary correction coefficient for each flow value set point based on the actual gas flow value and the theoretical gas flow control value; Based on each of the quadratic correction coefficients, a preset gas flow control value within a corresponding flow value range in the target mass flow controller is corrected.

2. The secondary flow correction method for a mass flow controller according to claim 1, characterized in that: Before obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller, the method further includes: When it is determined that the gas type of the gas passing through the target mass flow controller changes, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

3. The secondary flow correction method for a mass flow controller according to claim 2, characterized in that: The method further comprises: When it is determined that the measurement range of the target mass flow controller is converted, or when the accumulated operating time of the target mass flow controller reaches a preset threshold, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

4. The secondary flow correction method for a mass flow controller according to claim 1, characterized in that: The determining of the secondary correction coefficient of each flow value set point according to the actual gas flow value and the theoretical gas flow control value includes: The quadratic correction coefficient of each of the flow value set points is determined based on a ratio between the actual gas flow value and the preset gas flow control value.

5. The secondary flow correction method for a mass flow controller according to claim 1, characterized in that: The step of correcting a preset gas flow control value within a corresponding flow value range in the target mass flow controller based on each of the secondary correction coefficients includes: determining a first target correction coefficient and a second target correction coefficient, wherein the first target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value as a lower limit value within the flow value range; and the second target correction coefficient is the secondary correction coefficient corresponding to the theoretical gas flow control value as an upper limit value within the flow value range; interpolating the first target correction coefficient and the second target correction coefficient based on the position of the preset gas flow control value within the flow value range to obtain a third target correction coefficient; The preset gas flow control value is corrected according to the third target correction coefficient.

6. The secondary flow calibration method for a mass flow controller according to claim 1, characterized in that: The method further comprises: Adjusting each of the flow value set points according to the set point adjustment instruction information to obtain each adjusted flow value set point; The step of obtaining the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller includes: The actual gas flow value and the theoretical gas flow control value corresponding to each of the adjusted flow value set points in the target mass flow controller are obtained.

7. A secondary flow correction system for a mass flow controller, characterized in that: include: a secondary calibration acquisition module, configured to obtain actual gas flow values ​​and theoretical gas flow control values ​​corresponding to respective flow value set points in a target mass flow controller, wherein the target mass flow controller is a mass flow controller that has been calibrated using a preset calibration gas; and the actual gas flow values ​​represent gas flow values ​​currently measured through the flow value set points in the target mass flow controller; a calculation module, configured to determine a secondary correction coefficient for each flow value set point based on the actual gas flow value and the theoretical gas flow control value; The secondary flow correction module is used to correct the preset gas flow control value within the corresponding flow value range in the target mass flow controller based on each of the secondary correction coefficients.

8. The secondary flow correction system for a mass flow controller according to claim 7, characterized in that: The system further comprises: The data acquisition module is used to collect the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller when it is determined that the gas type of the gas passing through the target mass flow controller has changed.

9. The secondary flow correction system for a mass flow controller according to claim 8, characterized in that: The data acquisition module is also used for: When it is determined that the measurement range of the target mass flow controller is converted, or when the accumulated operating time of the target mass flow controller reaches a preset threshold, the actual gas flow value and the theoretical gas flow control value corresponding to each flow value set point in the target mass flow controller are collected.

10. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the secondary flow correction method for a mass flow controller according to any one of claims 1 to 6 is implemented.

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