A pressure control system and control method for a vacuum regulating valve

Abstract

This invention provides a vacuum regulating valve pressure control system and its control method, relating to the field of vacuum regulating valve pressure control technology. The control method includes obtaining a specified rotational speed through a valve rotational speed model, and then controlling the valve plate of the vacuum regulating valve to rotate to a specified angular position based on the specified rotational speed; the valve rotational speed model is established based on the PWM pulse frequency and the Simoid function. The control method of this invention solves the problem that current vacuum regulating valve pressure control systems cannot meet the response speed and stability requirements of production lines, achieving the effect of improving system response speed and stability.

Description

Technical Field

[0001] This invention relates to the field of vacuum regulating valve pressure control technology, and more specifically, to a vacuum regulating valve pressure control system and its control method. Background Technology

[0002] Control valves effectively regulate the pressure of vacuum chambers under various vacuum environments and are widely used in semiconductor processes, new display manufacturing, and solar energy. In vacuum systems, control valves are installed at the inlet or outlet and connected to the vacuum chamber equipment. Pressure control is achieved by adjusting the valve plate through a control algorithm. However, current vacuum control valve pressure control systems fail to simultaneously balance speed and precision when controlling valve plate rotation. When the valve plate rotates at high speed, its actual position often deviates significantly from the designated position, resulting in unstable pressure within the vacuum chamber. Consequently, current vacuum control valve pressure control systems cannot meet the response speed and stability requirements of production lines.

[0003] There is currently no effective technical solution to the above problems. Summary of the Invention

[0004] The purpose of this invention is to provide a vacuum regulating valve pressure control system and its control method, which solves the problem that the current vacuum regulating valve pressure control system cannot meet the response speed and stability requirements of the production line, thereby improving the system response speed and stability.

[0005] In a first aspect, the present invention provides a control method for a vacuum regulating valve pressure control system, comprising obtaining a specified rotational speed through a valve rotational speed model, and controlling the valve plate of the vacuum regulating valve to rotate to a specified angular position according to the specified rotational speed; the valve rotational speed model is established based on PWM pulse frequency and Simoid function.

[0006] The control method of the vacuum regulating valve pressure control system of the present invention utilizes a preset valve speed model to achieve better control of the valve plate speed, thereby ensuring that the valve plate can reach the specified position faster and more accurately, and thus improving the system's response speed and stability.

[0007] Furthermore, the specific expression of the Simoid function is as follows:

[0008] ;

[0009] in, For about The Simoid function, Less than Integer variables, The preset number of acceleration attempts;

[0010] The specific expression for the valve rotation speed model is as follows:

[0011] ;

[0012] in, For about Valve rotation speed model, This is the minimum value of the PWM pulse frequency. This represents the maximum value of the PWM pulse frequency.

[0013] Furthermore, obtaining the specified rotational speed through the valve rotational speed model includes calculating the specified rotational speed according to the following formula:

[0014] ;

[0015] in, For the specified rotational speed, These are preset parameters.

[0016] Furthermore, when the vacuum regulating valve is energized, the following steps are performed:

[0017] A1. The valve plate is controlled to rotate at the specified speed by a stepper driver;

[0018] A2. Detect the valve plate's stall condition and, when the valve plate is detected to be obstructed, control the valve plate to stop rotating;

[0019] A3. Using the valve speed model, control the stepper driver to drive the valve plate to reverse at the specified speed according to a preset number of steps;

[0020] A4. After the valve plate stops rotating, restore the vacuum regulating valve pressure control system to its initial state.

[0021] This step ensures that the system returns to a known and controllable initial state each time it is powered on, laying the foundation for subsequent precise control.

[0022] Furthermore, the specific steps in step A2 include:

[0023] A21. Detect the stall condition of the valve plate according to the following steps:

[0024] A211. Obtain the two-phase current difference of the stepper driver;

[0025] A212. When the current difference between the two phases increases, it is determined that the valve plate is blocked and the valve plate is controlled to stop rotating.

[0026] This method can react in the early stages of valve plate obstruction, effectively preventing valve plate damage due to continuous force. At the same time, it uses stall as a signal to reverse the valve plate a certain number of steps, allowing the valve plate to return to zero more accurately.

[0027] Furthermore, the initial state setting steps of the vacuum regulating valve pressure control system include:

[0028] B1. Control the valve plate to rotate at the specified speed to close the vacuum regulating valve;

[0029] B2. Using the valve speed model, control the valve plate to rotate 90° at the specified speed and record the cavity pressure of the vacuum chamber at different angular positions of the valve plate to obtain a data table on the angular position of the valve plate and the cavity pressure of the vacuum chamber;

[0030] B3. Control the angle position of the valve plate according to the data table so that the vacuum chamber reaches the specified chamber pressure.

[0031] Secondly, the present invention provides a vacuum regulating valve pressure control system, including a stepper driver and a vacuum regulating valve. The stepper driver is used to obtain a specified speed through a valve speed model, and then control the valve plate of the vacuum regulating valve to rotate to a specified angular position according to the specified speed. The valve speed model is established based on the PWM pulse frequency and the Simoid function.

[0032] The device provided by this invention enables the system to precisely control the rotation speed and angular position of the valve plate, thereby achieving precise adjustment of the vacuum chamber pressure.

[0033] Furthermore, it also includes a zero-return controller, which performs the following steps when the vacuum regulating valve is energized:

[0034] A1. The valve plate is controlled to rotate at the specified speed by a stepper driver;

[0035] A2. Detect the valve plate's stall condition and, when the valve plate is detected to be obstructed, control the valve plate to stop rotating;

[0036] A3. Using the valve speed model, control the stepper driver to drive the valve plate to reverse at the specified speed according to a preset number of steps;

[0037] A4. After the valve plate stops rotating, restore the vacuum regulating valve pressure control system to its initial state.

[0038] Furthermore, the zero-return controller performs the following actions when detecting a stall condition on the valve plate:

[0039] A21 detects the stall condition of the valve plate according to the following steps:

[0040] A211. Obtain the two-phase current difference of the stepper driver;

[0041] A212. When the current difference between the two phases increases, it is determined that the valve plate is blocked and the valve plate is controlled to stop rotating.

[0042] Furthermore, it also includes an initialization controller, which is used to perform the following steps:

[0043] B1. Using the valve speed model, control the valve plate to rotate at the specified speed to close the vacuum regulating valve;

[0044] B2. Using the valve speed model, control the valve plate to rotate 90° at the specified speed and record the cavity pressure of the vacuum chamber at different angular positions of the valve plate to obtain a data table on the angular position of the valve plate and the cavity pressure of the vacuum chamber;

[0045] B3. Control the angle position of the valve plate according to the data table so that the vacuum chamber reaches the specified chamber pressure.

[0046] As can be seen from the above, the control method of the vacuum regulating valve pressure control system provided by the present invention establishes a valve speed model based on PWM pulse frequency and Simoid function to obtain the valve speed model that can control the valve to reach the specified angle position more quickly and smoothly, thereby effectively reducing the error between its actual position and the specified position, making the cavity pressure of the vacuum chamber more stable, thereby improving the system response speed and stability.

[0047] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0048] Figure 1 A flowchart illustrating a control method for a vacuum regulating valve pressure control system provided in an embodiment of the present invention.

[0049] Figure 2 This is a schematic diagram of a vacuum regulating valve pressure control system provided in an embodiment of the present invention.

[0050] Label Explanation:

[0051] 100. Stepper driver; 200. Vacuum regulating valve; 300. Zero homing controller; 400. Initialization controller. Detailed Implementation

[0052] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention 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 the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0053] 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 invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0054] In vacuum regulating valve pressure control systems, the vacuum chamber needs to switch from one pressure state to another within a very short time to adapt to different process steps. However, existing vacuum regulating valve systems often experience positional errors when the valve plate rotates at high speed, causing the pressure in the vacuum chamber to fail to stabilize at the expected value. This instability directly affects product quality and production efficiency.

[0055] For reference, see the appendix. Figure 1 This invention provides a control method for a vacuum regulating valve pressure control system, comprising obtaining a specified speed through a valve speed model, and controlling the valve plate of the vacuum regulating valve to rotate to a specified angular position according to the specified speed; the valve speed model is established based on PWM pulse frequency and Simoid function.

[0056] The valve speed model in this embodiment can smoothly accelerate the valve plate from a stationary state to its maximum speed, and then smoothly decelerate when approaching the target position, thereby avoiding the sudden acceleration and deceleration problems in traditional control methods.

[0057] The valve rotation speed model is closely linked to the stepper driver and the vacuum regulating valve. The stepper driver's rotation is controlled by adjusting the PWM signal based on the specified rotation speed output from the model. The valve plate of the vacuum regulating valve achieves precise angular positioning based on the stepper driver's rotation. This linkage allows the system to improve response speed while maintaining accuracy.

[0058] The technical solution of this application achieves precise control of the valve plate through a valve rotation speed model. First, the system calculates the required valve plate angle position based on the current vacuum chamber pressure and the target pressure. Then, a smooth speed curve is generated by the valve rotation speed model. Finally, the stepper driver controls the valve plate of the vacuum regulating valve to move from the current position to the target position according to this speed curve.

[0059] During valve plate rotation, the system continuously monitors the vacuum chamber pressure and valve plate position. If the detected pressure change trend deviates from expectations, the system can adjust the speed curve in real time to ensure that the target pressure is ultimately reached. This closed-loop control method greatly improves the system's stability and accuracy.

[0060] Compared with traditional control methods, the technical solution of this application has the following advantages:

[0061] First, by combining the PWM pulse frequency and the sigmoid function, more precise and smooth speed control is achieved. This not only improves the accuracy of valve plate position control but also reduces mechanical stress and wear in the system, extending the service life of the equipment.

[0062] Secondly, the introduction of the valve speed model enables the system to adaptively adjust control parameters according to different working conditions, thereby improving the system's flexibility and adaptability.

[0063] Finally, this control method significantly improves the system's response speed and stability, making pressure control more reliable and efficient, and better able to meet the stringent requirements of fields such as semiconductor processes, new display manufacturing, and solar energy.

[0064] In practical applications, the PWM pulse frequency range can be set, for example, from 100Hz to 10kHz, to adapt to different speed requirements. Simultaneously, the accuracy of the angular position can be set according to actual needs, such as ±0.1 degrees. Furthermore, this method can be combined with other control techniques, such as incorporating a simple feedback mechanism to check the actual position after each adjustment and make fine adjustments if errors exist.

[0065] To illustrate the implementation of this application, the following example uses a photolithography apparatus in semiconductor manufacturing processes. A vacuum regulating valve is installed on the vacuum chamber of the photolithography apparatus to precisely control the pressure within the chamber.

[0066] First, a valve rotation speed model is established. When the vacuum chamber pressure needs to be adjusted from 100Pa to 50Pa, the required rotation angle of the valve plate is calculated based on the pressure change, assumed to be 30°. Then, the valve plate speed curve is obtained using the valve rotation speed model. Based on the speed curve, the valve plate is controlled to rotate at different speeds during the movement process until it finally reaches the required angular position.

[0067] Next, the calculated specified rotational speed is converted into a corresponding PWM pulse frequency and sent to the stepper driver. The stepper driver then drives the vacuum regulating valve plate to rotate precisely to the specified angular position based on the received PWM signal. Throughout the process, the system continuously monitors the actual pressure in the vacuum chamber. If a deviation between the actual pressure and the target pressure is detected, fine-tuning is performed based on the valve rotational speed model to ensure the pressure remains stable at 50 Pa.

[0068] By using a valve rotation speed model based on PWM pulse frequency and the Sigmoid function, this system can precisely adjust the vacuum chamber pressure from 100 Pa to 50 Pa within 0.1 seconds, while maintaining pressure stability of ±0.1 Pa. This high-speed response and precise control capability significantly improves the efficiency and quality of the photolithography process.

[0069] Compared to existing technologies, traditional vacuum regulating valve control systems typically employ linear control methods, making it difficult to accurately describe the nonlinear characteristics of valve plate movement. This leads to significant positional errors during high-speed adjustments, consequently affecting the accuracy of pressure control. For example, a certain existing technology requires 0.5 seconds to complete pressure adjustment under the same conditions, and pressure fluctuations can reach ±1 Pa.

[0070] The valve rotation speed model based on PWM pulse frequency and the sigmoid function introduced in this application can more accurately describe the valve plate motion characteristics, especially the nonlinear behavior at high speeds. This allows the system to significantly improve position control accuracy while maintaining high-speed response. Therefore, this application not only resolves the contradiction between speed and accuracy but also significantly improves the overall performance and reliability of the vacuum regulating valve, as well as the stability of the system for pressure control.

[0071] Furthermore, existing control methods are often ill-suited to vacuum systems of varying specifications. The technical solution presented in this application, through adjustable model parameters, can flexibly adapt to vacuum systems of different volumes and pressure ranges, significantly improving the system's versatility and adaptability.

[0072] Finally, traditional methods are prone to pressure fluctuations and mechanical shocks during high-speed adjustment, affecting system stability and service life. The smooth speed control proposed in this application effectively solves this problem, not only improving the stability of pressure control but also extending the equipment's service life and reducing maintenance costs.

[0073] Specifically, the expression for the Simoid function is:

[0074] ;

[0075] in, For about The Simoid function, Less than Integer variables, The preset number of acceleration attempts;

[0076] The specific expression for the valve speed model is as follows:

[0077] ;

[0078] in, For about Valve rotation speed model, This is the minimum value of the PWM pulse frequency. This represents the maximum value of the PWM pulse frequency.

[0079] Specifically, obtaining a specified speed through the valve speed model includes calculating the specified speed according to the following formula:

[0080] ;

[0081] in, For a specified rotational speed, These are preset parameters.

[0082] It should be noted that the preset parameters need to be determined according to the specifications of the actual stepper driver used. The value range is generally 1-256. For example, if the stepper driver uses a 1.8° stepper motor, the value is 32, but it is not limited to this.

[0083] In some embodiments, when the vacuum regulating valve is energized, the following steps are performed:

[0084] A1. The valve plate is controlled to rotate at a specified speed by a stepper driver;

[0085] A2. Detect the valve plate's jamming status and control the valve plate to stop rotating when obstruction is detected;

[0086] A3. Using a valve speed model, control the stepper driver to drive the valve plate to reverse at a specified speed according to a preset number of steps;

[0087] A4. After the valve plate stops rotating, restore the vacuum regulating valve pressure control system to its initial state.

[0088] In this embodiment, a stepper driver controls the valve plate to rotate at a specified speed, ensuring the accuracy and controllability of the valve plate's movement. Secondly, the system detects valve plate stall; if obstruction is detected, the valve plate is immediately stopped. This step protects the stepper driver and improves the system's safety and reliability. Then, using a valve speed model, the stepper driver drives the valve plate to reverse at a specified speed according to a preset number of steps. This step, by precisely controlling the number of reversal steps, ensures the valve plate accurately returns to its initial position. Finally, after the valve plate stops rotating, the vacuum regulating valve pressure control system is restored to its initial state. This step ensures that the system returns to a known and controllable initial state after each power-on, laying the foundation for subsequent precise control.

[0089] In practical implementation, there are several ways to control the stepper driver to rotate the valve plate at a specified speed. For example, a pulse width modulation (PWM) signal can be used to control the speed of the stepper driver, and different speeds can be achieved by adjusting the frequency and duty cycle of the PWM signal. Another method is to use microstepping technology, which achieves finer speed control by subdividing each step of the stepper driver.

[0090] Detecting valve plate stall can be achieved by monitoring changes in the stepper driver's current. When the valve plate is obstructed, the motor current will suddenly increase. A current threshold can be set; when the detected current exceeds this threshold, the motor should stop immediately. Alternatively, an encoder can be used to monitor the actual position of the valve plate. If the valve plate position remains unchanged for an extended period while the motor continues to run, it is determined to be stalled.

[0091] A key aspect of this solution is controlling the valve plate's reverse rotation using a valve speed model. This model, built upon PWM pulse frequency and the sigmoid function, allows for precise control of the valve plate's reverse rotation speed and position. For example, a preset number of reverse rotation steps can be set to 1000, and the model calculates the specific rotational speed for each step, achieving smooth acceleration and deceleration.

[0092] The interconnections and interactions between these steps form a closed-loop control system. A stepper driver controls the valve plate rotation while simultaneously detecting stall in real time, ensuring system safety. Upon detecting stall, the system immediately stops and reverses, a rapid response mechanism that significantly improves system reliability. Finally, the system is restored to its initial state, laying the foundation for subsequent precise pressure control.

[0093] When the vacuum regulating valve is powered on, the technical solution of this application first controls the valve plate to rotate at a specified speed via a stepper driver. This step utilizes the aforementioned valve speed model, which can precisely control the speed of the valve plate and avoid position errors caused by excessively fast start-up speed in traditional methods. For example, the initial speed can be set to 60 rpm, and then gradually increased to 200 rpm according to the valve speed model.

[0094] Next, the system monitors the valve plate's stall status in real time. This is achieved by monitoring the two-phase current difference of the stepper driver. When a sudden increase in the two-phase current difference is detected, for example, exceeding 0.5A, the system determines that the valve plate is obstructed and immediately controls the valve plate to stop rotating. This mechanism effectively prevents mechanical damage that could result from forced rotation of the valve plate.

[0095] After detecting and stopping a stall, the system uses a valve speed model to control a stepper driver to reverse the valve plate at a specified speed according to a preset number of steps. This preset number of steps can be set according to actual conditions, for example, 500 steps. During the reversal process, the system dynamically adjusts the speed based on the valve speed model to ensure the smoothness and accuracy of the reversal.

[0096] Finally, after the valve plate stops rotating, the system restores the vacuum regulating valve pressure control system to its initial state. This includes clearing the encoder register and position data on the MCU, removing any error flags, and setting the system parameters to predetermined initial values. This step prevents errors from accumulating with each control operation, ensuring that the system starts operating from a known, stable state each time it is powered on.

[0097] Through this series of steps, the technical solution of this application effectively solves the problem of precise control and initialization when the vacuum regulating valve is powered on. By restoring the system to a known initial state, this solution ensures that the system is in a predictable and controllable state after each startup. This greatly improves the stability and reliability of the system and reduces control errors caused by uncertainties in the initial state.

[0098] In some embodiments, the specific steps in step A2 include:

[0099] A21. Check the valve plate for stalling according to the following steps:

[0100] A211. Obtain the two-phase current difference of the stepper driver;

[0101] A212. When the current difference between the two phases increases, it is determined that the valve plate is blocked and the valve plate is controlled to stop rotating.

[0102] In practical applications, by installing an obstruction on the drive shaft between the stepper driver and the valve plate to block the return to zero position, a stall phenomenon is generated when the valve plate rotates. When stall occurs, it indicates that the valve plate has reached the predetermined position. Subsequently, in conjunction with the steps of the above embodiment, the valve plate is controlled to reverse according to a predetermined number of steps, using this position as a reference. Compared to controlling the valve plate to rotate directly to the preset return to zero position, the actual position of the valve plate may have an error with the return to zero position. This error is often greater than the error of the stepper driver controlling the valve plate to move according to a predetermined number of steps. Therefore, the stall is used as a signal to reverse the valve plate by a certain number of steps, so that the valve plate can return to zero more accurately (not rotating to the return to zero position, but being a certain number of steps away from the return to zero position, which is equivalent to returning to zero).

[0103] This embodiment detects valve plate stall by monitoring the two-phase current difference of the stepper driver. When the valve plate is operating normally, the two-phase current difference of the stepper driver should remain within a relatively stable range. If the valve plate encounters an obstacle or is obstructed by other external forces, the motor needs to increase its output torque to overcome these resistances, which leads to an increase in the two-phase current difference. By monitoring the changes in the two-phase current difference in real time, the system can quickly detect whether the valve plate is obstructed. Once an increase in the two-phase current difference is detected, the system immediately determines that the valve plate is obstructed and quickly controls the valve plate to stop rotating. This method can react in the early stages of valve plate obstruction, effectively preventing damage to the valve plate due to continuous force.

[0104] In practice, the two-phase current difference of a stepper driver can be obtained in several ways. One method is to directly measure the two-phase current of the stepper driver using a current sensor and then calculate the difference. Another method is to indirectly calculate the current difference by measuring the output voltage of the motor driver. Additionally, the current difference can also be estimated by monitoring the back electromotive force of the stepper driver.

[0105] The criteria for determining an increase in the two-phase current difference can be set according to the specific application scenario. For example, a fixed threshold can be set, and an increase is considered when the current difference exceeds this threshold. Alternatively, a dynamic threshold can be used, dynamically adjusting the judgment criteria based on historical motor operating data. More complex algorithms may consider the rate of change of the current difference to more accurately determine whether the valve plate is obstructed.

[0106] In practical applications, this method is implemented as follows: First, the system controls the valve plate to rotate at a specified speed via a stepper driver. During rotation, the system continuously monitors the two-phase current of the stepper driver. Assuming the normal operating current difference is 0.1A and the system threshold is set to 0.3A, when the valve plate encounters an obstacle, the motor needs to increase torque, causing the two-phase current difference to rapidly rise to 0.4A. The system detects this change, immediately determines that the valve plate is obstructed, and issues a stop command within 10 milliseconds, controlling the valve plate to stop rotating. This process, from detection to response, takes only tens of milliseconds, effectively preventing damage to the valve plate and motor.

[0107] This current difference-based detection method offers several advantages over traditional mechanical sensor methods. First, it eliminates the need for additional mechanical components, reducing system complexity and potential failure points. Second, the current detection response is extremely fast, reacting even to slight resistance on the valve plate, significantly improving the timeliness of protection. Furthermore, the sensitivity of this method can be adjusted via software to adapt to different working environments and requirements, offering high flexibility.

[0108] In some embodiments, the initial state setup step of the vacuum regulating valve pressure control system includes:

[0109] B1. Control the valve plate to rotate at a specified speed to close the vacuum regulating valve;

[0110] B2. Using the valve speed model, control the valve plate to rotate 90° at a specified speed and record the cavity pressure corresponding to the vacuum chamber at different angular positions of the valve plate to obtain a data table on the angular position of the valve plate and the cavity pressure of the vacuum chamber;

[0111] B3. Control the angle and position of the valve plate according to the data sheet to make the vacuum chamber reach the specified chamber pressure.

[0112] In this embodiment, the control valve plate rotates at a specified speed to close the vacuum regulating valve. This step ensures the system starts from a known starting point. Then, using a valve speed model, the valve plate is rotated 90°, while the cavity pressure at different angular positions is recorded in a scanning-like manner. This step establishes the relationship between the valve plate's angular position and the cavity pressure, forming a data table. This data table provides the foundation for subsequent precise control. Finally, based on the obtained data table, the system can accurately control the angular position of the valve plate, thereby enabling the vacuum chamber to reach the specified cavity pressure.

[0113] When controlling the valve plate to rotate 90° using a valve speed model, different sampling strategies can be employed. For example, pressure data can be recorded every 1°, or non-uniform sampling can be used, increasing the sampling frequency in areas of significant pressure variation. This flexible sampling strategy can improve the accuracy of the data table while optimizing data storage and processing efficiency.

[0114] The creation of the data table is the core of this technical solution. The data table can be stored using data structures such as a two-dimensional array or a hash table, with the key being the valve plate angle and the value being the corresponding cavity pressure. This structure facilitates fast lookup and interpolation calculations. In practical applications, the influence of environmental factors such as temperature and humidity on pressure may need to be considered; therefore, the data table structure can be expanded to add these parameters as additional dimensions.

[0115] When controlling the valve plate angle position based on a data table, interpolation algorithms can be used to handle situations where the target pressure is not listed in the data table. Commonly used interpolation methods include linear interpolation and spline interpolation; the appropriate algorithm can be selected based on the system's accuracy requirements. Furthermore, adaptive control algorithms can be introduced to dynamically adjust the valve plate position based on real-time feedback, further improving control accuracy.

[0116] When used in conjunction with the aforementioned valve rotation speed model, this technical solution enables a more efficient initialization process. The valve rotation speed model provides a precise control basis for valve plate rotation, while the data table established through actual measurements in this solution provides a direct correspondence between valve plate position and cavity pressure. This combination not only improves the accuracy of initialization but also significantly shortens the initialization time, as the system can directly and quickly locate the valve plate position corresponding to the target pressure based on the data table, without requiring multiple attempts and adjustments.

[0117] In practical applications, this technical solution can be implemented as follows: First, upon system startup, the control valve plate rotates to the fully closed position at a speed of 2 revolutions per second. Then, using a valve rotation speed model, the control valve plate slowly opens at a speed of 1 revolution per second, recording the cavity pressure every 1° of rotation, until it rotates 90°. This process typically takes 1.5-2 seconds. The recorded data forms a data table containing 90 data points. Assuming the target cavity pressure is 50 Pa, the system queries the data table to find the two data points closest to 50 Pa; for example, 48 Pa corresponds to 45°, and 52 Pa corresponds to 46°. Through linear interpolation, the system calculates that the angle corresponding to 50 Pa is approximately 45.5°. Finally, the system precisely controls the valve plate to rotate to the 45.5° position, achieving precise control of the cavity pressure.

[0118] This solution establishes a data table through actual measurements, accurately reflecting the characteristics of a specific system and significantly improving control precision. Furthermore, by establishing the data table in a single scan, the target pressure can be quickly and accurately located subsequently, significantly improving system response speed and efficiency. This method not only enables the system to learn autonomously and adapt to various operating conditions but also provides a reliable foundation for subsequent pressure control, effectively enhancing the overall performance of the vacuum regulating valve pressure control system.

[0119] Reference Appendix Figure 2 The present invention provides a vacuum regulating valve pressure control system, including a stepper driver 100 and a vacuum regulating valve 200. The stepper driver 100 is used to obtain a specified speed through a valve speed model, and then control the valve plate of the vacuum regulating valve 200 to rotate to a specified angle position according to the specified speed. The valve speed model is established based on the PWM pulse frequency and the Simoid function.

[0120] This vacuum regulating valve pressure control system mainly comprises two core components: a stepper driver 100 and a vacuum regulating valve 200. The key to the system lies in controlling the valve plate rotation using a valve speed model. The stepper driver 100 controls the valve plate of the vacuum regulating valve 200 to rotate to a specified angular position based on the specified speed obtained from the valve speed model. This precise control enables accurate regulation of the vacuum chamber pressure. The valve speed model is based on PWM pulse frequency and the Sigmoid function. The PWM pulse frequency provides precise speed control, while the Sigmoid function enables smooth acceleration and deceleration, avoiding abrupt changes in valve plate movement, thereby improving control stability and accuracy. Through this method, the system can precisely control the rotation speed and angular position of the valve plate, thus achieving precise regulation of the vacuum chamber pressure. Compared to traditional control methods, this model-based control method offers higher accuracy, better dynamic response characteristics, and higher stability.

[0121] In some embodiments, the vacuum regulating valve pressure control system further includes a zero-return controller 300, which performs the following steps when the vacuum regulating valve 200 is powered on:

[0122] A1. The valve plate is controlled to rotate at a specified speed by stepper driver 100;

[0123] A2. Detect the valve plate's jamming status and control the valve plate to stop rotating when obstruction is detected;

[0124] A3. Using the valve speed model, control the stepper driver 100 to drive the valve plate to reverse at a specified speed according to a preset number of steps;

[0125] A4. After the valve plate stops rotating, restore the vacuum regulating valve pressure control system to its initial state.

[0126] The homing controller 300 is the core of the entire homing process, responsible for controlling and coordinating the execution of each step. It can be implemented using a microcontroller or a programmable logic controller (PLC), managing the entire homing process through preset program logic. The homing controller 300 is connected to the stepper driver 100 and various sensors, receiving and processing relevant signals and making corresponding control decisions.

[0127] In some embodiments, the homing controller 300 performs the following actions when detecting a stall condition on the valve plate:

[0128] A21 checks the valve plate's stall condition according to the following steps:

[0129] A211. Obtain the two-phase current difference of stepper driver 100;

[0130] A212. When the current difference between the two phases increases, it is determined that the valve plate is blocked and the valve plate is controlled to stop rotating.

[0131] This technical solution detects valve plate stall by monitoring the two-phase current difference of the stepper motor. When the valve plate is operating normally, the two-phase current difference of the stepper motor should remain within a relatively stable range. If the valve plate encounters an obstacle or other obstruction, the motor needs to increase its output torque to overcome the resistance, which leads to an increase in the two-phase current difference. By monitoring the changes in the two-phase current difference in real time, the system can quickly detect whether the valve plate is obstructed. Once an increase in the two-phase current difference is detected, the zero-return controller 300 immediately determines that the valve plate is obstructed and quickly controls the valve plate to stop rotating. This method can detect the problem as soon as the valve plate begins to be obstructed, avoiding potential damage caused by continued forced rotation of the valve plate.

[0132] In some embodiments, the vacuum regulating valve pressure control system further includes an initialization controller 400, which performs the following steps:

[0133] B1. Use a valve speed model to control the valve plate to rotate at a specified speed to close the vacuum regulating valve 200;

[0134] B2. Using the valve speed model, control the valve plate to rotate 90° at a specified speed and record the cavity pressure corresponding to the vacuum chamber at different angular positions of the valve plate to obtain a data table on the angular position of the valve plate and the cavity pressure of the vacuum chamber;

[0135] B3. Control the angle and position of the valve plate according to the data sheet to make the vacuum chamber reach the specified chamber pressure.

[0136] The initialization controller 400 plays a crucial role in the vacuum regulating valve pressure control system. It establishes the correspondence between the valve plate angle position and the vacuum chamber pressure through a series of steps, enabling the system to have adaptive learning capabilities. The data table is the foundation for achieving precise pressure control; the system can adjust the valve plate angle position according to this data table to achieve the specified chamber pressure. This method allows the system to quickly and accurately adjust the valve plate position under different pressure requirements.

[0137] In this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, without necessarily requiring or implying any such actual relationship or order between these entities or operations.

[0138] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a vacuum regulating valve pressure control system, characterized in that, The vacuum regulating valve pressure control system includes a stepper driver and a vacuum regulating valve. The control method of the vacuum regulating valve pressure control system includes controlling the stepper driver to obtain a specified speed through a valve speed model, and then controlling the valve plate of the vacuum regulating valve to rotate to a specified angular position according to the specified speed. The valve speed model is established based on the PWM pulse frequency and the Simoid function. The specific expression for the Simoid function is: ； in, For about The Simoid function, Less than Integer variables, The preset number of acceleration attempts; The specific expression for the valve rotation speed model is as follows: ； in, For about Valve rotation speed model, This is the minimum value of the PWM pulse frequency. This represents the maximum value of the PWM pulse frequency.

2. The control method for the vacuum regulating valve pressure control system according to claim 1, characterized in that, Obtaining a specified rotational speed through a valve rotational speed model includes calculating the specified rotational speed according to the following formula: ； in, For the specified rotational speed, These are preset parameters.

3. The control method for the vacuum regulating valve pressure control system according to claim 1, characterized in that, When the vacuum regulating valve is energized, the following steps are performed: A1. The valve plate is controlled to rotate at the specified speed by a stepper driver; A2. Detect the valve plate's stall condition and, when the valve plate is detected to be obstructed, control the valve plate to stop rotating; A3. Using the valve speed model, control the stepper driver to drive the valve plate to reverse at the specified speed according to a preset number of steps; A4. After the valve plate stops rotating, restore the vacuum regulating valve pressure control system to its initial state.

4. The control method for the vacuum regulating valve pressure control system according to claim 3, characterized in that, The specific steps in step A2 include: A21. Detect the stall condition of the valve plate according to the following steps: A211. Obtain the two-phase current difference of the stepper driver; A212. When the current difference between the two phases increases, it is determined that the valve plate is blocked and the valve plate is controlled to stop rotating.

5. The control method for the vacuum regulating valve pressure control system according to claim 3, characterized in that, The initial state setup steps for the vacuum regulating valve pressure control system include: B1. Control the valve plate to rotate at the specified speed to close the vacuum regulating valve; B2. Using the valve speed model, control the valve plate to rotate 90° at the specified speed and record the cavity pressure of the vacuum chamber at different angular positions of the valve plate to obtain a data table on the angular position of the valve plate and the cavity pressure of the vacuum chamber; B3. Control the angle position of the valve plate according to the data table so that the vacuum chamber reaches the specified chamber pressure.

6. The control method for the vacuum regulating valve pressure control system according to claim 1, characterized in that, The vacuum regulating valve pressure control system further includes a zero-return controller, which is used to perform the following steps when the vacuum regulating valve is powered on: A1. The valve plate is controlled to rotate at the specified speed by a stepper driver; A2. Detect the valve plate's stall condition and, when the valve plate is detected to be obstructed, control the valve plate to stop rotating; A3. Using the valve speed model, control the stepper driver to drive the valve plate to reverse at the specified speed according to a preset number of steps; A4. After the valve plate stops rotating, restore the vacuum regulating valve pressure control system to its initial state.

7. The control method for the vacuum regulating valve pressure control system according to claim 6, characterized in that, The zero-return controller performs the following actions when detecting a stall condition on the valve plate: A21. Detect the stall condition of the valve plate according to the following steps: A211. Obtain the two-phase current difference of the stepper driver; A212. When the current difference between the two phases increases, it is determined that the valve plate is blocked and the valve plate is controlled to stop rotating.

8. The control method for the vacuum regulating valve pressure control system according to claim 1, characterized in that, The vacuum regulating valve pressure control system further includes an initialization controller, which is used to perform the following steps: B1. Using the valve speed model, control the valve plate to rotate at the specified speed to close the vacuum regulating valve; B2. Using the valve speed model, control the valve plate to rotate 90° at the specified speed and record the cavity pressure of the vacuum chamber at different angular positions of the valve plate to obtain a data table on the angular position of the valve plate and the cavity pressure of the vacuum chamber; B3. Control the angle position of the valve plate according to the data table so that the vacuum chamber reaches the specified chamber pressure.

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