Vacuum slide gate valve control system and control method

Abstract

This invention relates to the field of valve control technology, and discloses a vacuum slide gate valve control system and method, including the following steps: a microcontroller reads user-set parameters; the valve is initialized; a model of the relationship between valve opening and cavity pressure is constructed; the microcontroller obtains the current valve opening through an AD converter, and obtains a preset valve opening based on a preset cavity pressure; a motor moves the current valve opening to the preset valve opening. This invention can learn the slide gate valve pumping model in real time after each start-up and update the values ​​of parameters A, α, and β, improving the accuracy of slide gate valve pressure control and the control response speed; the microcontroller connects to different types of encoders through different interfaces and can control different types of motors through different control methods, making it widely applicable. Furthermore, the encoder can read the valve opening in real time, eliminating the need for limit switches, reducing the overall system size, and enabling real-time control of cavity pressure.

Description

Technical Field

[0001] This invention relates to the field of valve control technology, and in particular to a vacuum slide gate valve control system and control method. Background Technology

[0002] Precise high-vacuum pressure control is crucial in fields such as semiconductor manufacturing, thin film deposition, surface science experiments, and precision instrument processing. Currently, different types of vacuum gate valves are equipped with different types of motors, requiring the design of drive circuits and drivers; limit switches are needed to indicate that the valve has moved into position; and the chamber pressure cannot be controlled. Summary of the Invention

[0003] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0004] The vacuum slide gate valve control method includes the following steps:

[0005] S1. The microcontroller reads the user-set parameters;

[0006] S2. Initialize the valve and record the vacuum count value, valve opening degree and its corresponding encoder position, vacuum pump pressure change rate, and cavity pressure change rate data.

[0007] S3. Construct a model of the relationship between valve opening and cavity pressure based on vacuum count data, valve opening degree, vacuum pump pressure change rate, and cavity pressure change rate.

[0008] S4. The microcontroller obtains the current valve opening degree through AD and obtains the preset valve opening degree based on the preset cavity pressure. The motor moves the current valve opening degree to the preset valve opening degree.

[0009] Furthermore, in step S2, initializing the valve includes the following sub-steps:

[0010] S201. Run at low speed towards the valve closing direction until stall occurs, and record the encoder position at this point as the fully closed valve position x. min ;

[0011] S202. Run at low speed in the valve opening direction until stall occurs, and record the encoder position at this point as the fully open valve position x. max ;

[0012] S203. Record multiple encoder positions and valve openings between the fully closed and fully open positions of the valve, and establish the relationship between encoder positions and valve openings:

[0013]

[0014] Where k is a coefficient and y is the encoder position.

[0015] Furthermore, in step S3, constructing the model relating the valve opening to the cavity pressure includes the following sub-steps:

[0016] S301. Fully open the valve and introduce the preset flow rate. When the pressure change rate Pv of the cavity is 0 and the value of the vacuum gauge is greater than 100mv, close the valve.

[0017] S302, Preset at least three sets of valve opening degrees X1, X2 and X3, and the full opening degree of the valve X max The values ​​are 1000, where X1 is 1000, X2 is 2000, and X3 is 3000. The valve openings are sequentially opened to the preset values ​​X1, X2, and X3, and the chamber pressure change rate and vacuum pump pressure change rate are monitored respectively. When the chamber pressure change rate is 0, the chamber pressure at this time is recorded, and at least three sets of chamber pressure and vacuum pump pressure change rates are obtained.

[0018] S303. Establish a model for the relationship between valve opening and cavity pressure, where the vacuum pump pressure change rate includes both the boost pressure change rate and the depressurization pressure change rate. ,in For boost pressure change rate, For pressure reduction rate of change, The rate of change of cavity pressure is at this time. , A is a constant, α is the pressure exponent coefficient, β is the opening exponent coefficient, p is the preset cavity pressure, and X is the preset valve opening. Based on the multiple sets of cavity pressures and vacuum pump pressure change rates in S302, A, α, and β are obtained by nonlinear least squares method.

[0019] Furthermore, in step S4, the microcontroller calculates the current valve opening by reading the encoder value via AD, and calculates a preset valve opening based on a preset cavity pressure, wherein the preset valve opening... , The microcontroller controls the motor to operate by outputting a PWM value, which in turn controls the valve to move to the preset valve opening.

[0020] The vacuum gate valve control system includes a microcontroller. The microcontroller's SPI1 interface is connected to a power-down storage chip FM, its SPI2 interface is connected to a differential transceiver chip, its SP3 interface is connected to an AD converter, its serial ports 1 and 2 are both connected to a 485 chip, its AB encoder communication interface is connected to a differential receiver chip, its clock 1 interface is connected to a second-order filter amplifier circuit, a second-order filter circuit, and a current generation circuit, and its clock 2 interface is connected to an H-bridge driver chip. The H-bridge driver chip is connected to the motor through four sets of H-bridges.

[0021] The beneficial effects of this invention are:

[0022] This invention acquires pressure data in real time, effectively addressing the nonlinear characteristics of chamber gas leakage and slide gate valve evacuation. Each time the slide gate valve is activated, it learns the evacuation model in real time and updates the values ​​of parameters A, α, and β, improving the accuracy and response speed of the slide gate valve pressure control. Furthermore, the microcontroller connects to different types of encoders through different interfaces and uses various control methods to control different types of motors, ensuring broad applicability. The encoder also allows for real-time reading of the valve opening, eliminating the need for limit switches, reducing the overall system size, and enabling real-time control of the chamber pressure. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of the invention.

[0024] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a connection diagram for the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. All other embodiments obtained by those skilled in the art based on the described embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0027] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms "first," "second," and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0028] The vacuum slide gate valve control method includes the following steps:

[0029] S1. The microcontroller reads the user-set parameters;

[0030] In this invention, the microcontroller reads the power-down parameter FM from the power-down storage chip FM to ensure parameter consistency and enable the rapid, reliable, and safe start-up of the gate valve.

[0031] S2. Initialize the valve and record the vacuum count value, valve opening degree and its corresponding encoder position, vacuum pump pressure change rate, and cavity pressure change rate data.

[0032] Initializing the valve includes the following sub-steps:

[0033] S201. Run at low speed towards the valve closing direction until stall occurs, and record the encoder position at this point as the fully closed valve position x. min ;

[0034] S202. Run at low speed in the valve opening direction until stall occurs, and record the encoder position at this point as the fully open valve position x. max ;

[0035] S203. Record multiple encoder positions and valve openings between the fully closed and fully open positions of the valve, and establish the relationship between encoder positions and valve openings:

[0036]

[0037] Where k is a coefficient and y is the encoder position;

[0038] In this invention, the slide gate valve is initialized before each start-up. Each time the slide gate valve is used, the relationship between the encoder and the valve opening is re-established, improving the accuracy of valve control. Furthermore, by establishing the relationship between the encoder and the valve opening, the microcontroller can quickly and accurately calculate the current valve opening by reading the encoder values, facilitating subsequent valve operations.

[0039] S3. Construct a model of the relationship between valve opening and cavity pressure based on vacuum count data, valve opening degree, vacuum pump pressure change rate, and cavity pressure change rate.

[0040] Building a model of the relationship between valve opening and cavity pressure includes the following sub-steps:

[0041] S301. Fully open the valve and introduce the preset flow rate. When the pressure change rate Pv of the cavity is 0 and the value of the vacuum gauge is greater than 100mv, close the valve.

[0042] The system steady state is confirmed by using the dual conditions of cavity pressure change rate Pv=0 and vacuum gauge threshold (>100mV), thus avoiding transient data contamination caused by traditional timed sampling.

[0043] S302, Preset at least three sets of valve opening degrees X1, X2 and X3, and the full opening degree of the valve X max The values ​​are 1000, where X1 is 1000, X2 is 2000, and X3 is 3000. The valve opening is sequentially opened to the preset values ​​X1, X2, and X3, and the rate of change of the chamber pressure and the vacuum pump pressure are monitored respectively. When the rate of change of the chamber pressure is 0, the chamber pressure at this time is recorded, and at least three sets of chamber pressure and vacuum pump pressure change rates are obtained. The preset at least three opening values ​​form a pressure-opening characteristic curve. Its non-linear distribution can effectively capture sensitive changes in the small opening range and improve the accuracy of data processing.

[0044] S303. Establish a model for the relationship between valve opening and cavity pressure, where the vacuum pump pressure change rate includes both the boost pressure change rate and the depressurization pressure change rate. ,in For boost pressure change rate, For pressure reduction rate of change, The rate of change of cavity pressure is at this time. , Let A be a constant, α be the pressure exponent coefficient, β be the opening exponent coefficient, p be the preset chamber pressure, and X be the preset valve opening. Based on multiple sets of chamber pressures and vacuum pump pressure change rates in S302, A, α, and β are obtained through nonlinear least squares method. By using redundant measurements of at least three sets of data, the influence of single measurement errors on parameters A, α, and β can be suppressed.

[0045] S4. The microcontroller obtains the current valve opening degree via AD converter and calculates the preset valve opening degree based on the preset cavity pressure. The motor then moves the current valve opening degree to the preset valve opening degree. The microcontroller calculates the current valve opening degree by reading the encoder value via AD converter and calculates the preset valve opening degree based on the preset cavity pressure. The preset valve opening degree... , The microcontroller controls the motor to operate by outputting a PWM value, which in turn controls the valve to move to the preset valve opening.

[0046] The vacuum gate valve control system includes a microcontroller. The microcontroller's SPI1 interface is connected to a power-down storage chip FM, its SPI2 interface is connected to a differential transceiver chip, its SP3 interface is connected to an AD converter, its serial ports 1 and 2 are both connected to a 485 chip, its AB encoder communication interface is connected to a differential receiver chip, its clock 1 interface is connected to a second-order filter amplifier circuit, a second-order filter circuit, and a current generation circuit, and its clock 2 interface is connected to an H-bridge driver chip. The H-bridge driver chip is connected to the motor through four sets of H-bridges.

[0047] In this invention, the AD (analog-to-digital converter) is connected to the vacuum gauge via a vacuum gauge interface. The vacuum gauge is used to monitor the cavity pressure in real time. The power-down storage chip FM is used to store the power-down parameter FM, which is convenient for reading after the next start of the gate valve. In this invention, the microcontroller is connected to the encoder through different interfaces depending on the type of encoder. The differential transceiver chip connected to the microcontroller's SPI2 interface is used to connect to the SSI absolute encoder. The SSI absolute encoder has the advantages of high precision, strong anti-interference ability, and easy installation. It adopts a synchronous serial communication protocol and transmits data with the control system through an RS422 differential interface. The microcontroller's serial port 2 is connected to the 485 absolute encoder through a 485 chip. It features advantages such as long-distance transmission, strong anti-interference capability, and standardized communication protocols. It transmits data with the control system through standard protocols such as Modbus-RTU. The microcontroller's AB encoder communication interface is linked to the AB incremental encoder through a differential receiver chip. The AB incremental encoder outputs two-phase quadrature pulse signals (90° phase difference) through photoelectric conversion, producing square wave pulses with a 90° phase difference. The rotation direction is determined by the phase relationship (A leading B indicates forward rotation, B leading A indicates reverse rotation), as well as the Z-phase zero-position pulse. One pulse is output per revolution for reference point positioning. It has the advantages of simple structure, low cost, and fast response. The microcontroller of this invention can connect to different types of encoders, making it widely applicable.

[0048] In this invention, the microcontroller can drive four different types of drive motors. Specifically, the microcontroller can drive a brushed motor through a connected H-bridge drive chip; the microcontroller can drive a stepper motor through pulse drive; drive a brushless motor through square wave; and drive a servo motor through a space vector algorithm. The microcontroller of this invention can drive different types of motors simultaneously to adapt to various models of gate valves.

[0049] (1) Unless otherwise defined, the same reference numerals in the embodiments and drawings of this disclosure have the same meaning.

[0050] (2) The accompanying drawings of the embodiments of this disclosure only involve the structures involved in the embodiments of this disclosure. Other structures can be referred to the general design.

[0051] (3) For clarity, components or areas are enlarged in the drawings used to describe embodiments of the present disclosure. It will be understood that when an element is referred to as being “above” or “below” another element, the element may be “directly” located “above” or “below” the other element, or there may be an intermediate element.

[0052] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method of controlling a vacuum plug valve, characterized by: The method comprises the following steps: S1, the single-chip microcomputer reads user setting parameters; S2, initializing the valve, recording the vacuum counter value, the valve opening degree and its corresponding encoder position, the vacuum pump pressure change rate, the cavity pressure change rate data; S3, constructing a model of the valve opening degree and the cavity pressure relationship based on the vacuum counter value, the valve opening degree, the vacuum pump pressure change rate and the cavity pressure change rate data; The model of the valve opening degree and the cavity pressure relationship comprises the following sub-steps: S301, the valve is fully opened and a preset flow is introduced, and when the pressure change rate Pv of the cavity is 0 and the value of the vacuum counter is greater than 100mv, the valve is closed; S302、pre-set at least three groups of valve opening X1, X2 and X3, the full opening of the valve X max 1000 wherein X1 is 1000, X2 is 2000, X3 is 3000, in turn, the valve opening is opened to the pre-set X1, X2, X3, and the cavity pressure change rate and the vacuum pump pressure change rate are monitored respectively, when the cavity pressure change rate is 0, the cavity pressure at this time is recorded, and at least three groups of cavity pressure and vacuum pump pressure change rate are obtained; S303, a model of the relationship between the valve opening and the cavity pressure, wherein the vacuum pump pressure change rate includes a pressure increase change rate and a pressure decrease change rate, and wherein is the pressure increase change rate, is the pressure decrease change rate, is the cavity pressure change rate, and , A is a constant, a is a pressure index coefficient, β is an opening index coefficient, p is a preset cavity pressure, and X is a preset valve opening. A, a, and β are obtained by a nonlinear least squares method based on the multiple sets of cavity pressures and vacuum pump pressure change rates in S302. S4, the single-chip microcomputer acquires the current valve opening degree through AD, and obtains a preset valve opening degree based on a preset cavity pressure, and moves the current valve opening degree to the preset valve opening degree through the motor; The single-chip microcomputer calculates the current opening degree of the valve by reading the encoder value through AD, calculates the preset valve opening degree based on the preset cavity pressure, and calculates the preset valve opening degree , , The single-chip microcomputer controls the motor to run by outputting the control PWM value, and controls the valve to move to the preset valve opening degree.

2. The vacuum plug valve control method of claim 1, wherein: In the S2, initializing the valve comprises the following sub-steps: S201, run to the closed valve direction at low speed until stall occurs, record the encoder position at this point as the fully closed valve position x min ; S202, run at low speed to the open valve direction until the stall occurs, record the encoder position here as the valve full open position x max ; S203, recording a plurality of groups of encoder positions and valve opening degrees between the fully closed position and the fully open position of the valve, and constructing a relationship between the encoder position and the valve opening degree: ； Wherein k is a coefficient, and y is the encoder position.

3. Vacuum gate valve control system for use in a vacuum gate valve control method as claimed in claim 1 or 2, characterized in that: The single-chip microcomputer is connected with a power-down storage chip FM through an SPI1 interface, connected with a differential transceiver chip through an SPI2 interface, connected with an AD through an SP3 interface, connected with a 485 chip through a serial port 1 and a serial port 2, connected with a differential receiving chip through an AB encoder communication interface, connected with a second-order filter amplification circuit, a second-order filter circuit and a current generating circuit through a clock 1 interface, and connected with an H-bridge driving chip through a clock 2 interface. The H-bridge driving chip is connected with a motor through four groups of H-bridges.

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