A high-precision pressure controller with dynamic linear output

Abstract

This invention relates to the field of optical processing technology and provides a high-precision pressure controller with dynamic linear output. It includes a hardware control module responsible for program storage, computing power provision, and multi-voltage power supply; a hardware control module storing system configuration, force-PWM mapping table, and algorithm; a sensor acquisition module responsible for real-time acquisition of system operating status data; a pneumatic drive module responsible for converting electrical signals into mechanical pressure output, specifically including a push rod slider module, a pneumatic proportional valve controller, and a low-resistance compressed air cylinder; an algorithm processing module responsible for converting user commands into control signals; a host computer interaction module serving as the system's visual interface; a communication transmission module; and a safety protection module. This device avoids the instantaneous impact caused by direct pressurization in traditional controllers, meets the high-precision requirements of micro-force control in optical processing, and effectively protects brittle optical components, reducing the risk of processing damage.

Description

Technical Field

[0001] This invention relates to the field of optical processing technology and provides a high-precision pressure controller with dynamic linear output. Background Technology

[0002] Pressure controllers are devices that enable precise pressure control and are widely used in high-precision machining applications in aerospace, precision optical manufacturing, and other fields. In optical processing, especially in the grinding and polishing processes of large-diameter optical components, pressure controllers drive pneumatic actuators to precisely control the contact pressure between the grinding head and the surface of the optical component. This is a crucial piece of equipment for ensuring surface accuracy, preventing component damage, and improving processing consistency. Its dynamic pressure output characteristics directly determine the surface accuracy and surface roughness of the optical component, and have a decisive impact on the yield of high-end optical products.

[0003] Currently, dynamic force actuators for optical processing generally use compressed air as a power source. By adjusting the output air pressure, they drive air pipes and cylinder assemblies to apply pressure to the processing load. Existing technologies mostly rely on electro-proportional valves and pneumatic solenoid valves to construct the air circuit control loop, combined with displacement sensors or force sensors to achieve basic pressure feedback and displacement monitoring. Parameter settings are completed through a host computer or touch screen.

[0004] However, existing pressure controllers still have significant shortcomings in practical applications, primarily in the insufficient stability of the pressurized output. After receiving the target force value set in the software interface, the actuator directly jumps the pressure to the specified value without a smooth buffer transition, easily causing instantaneous impacts on brittle optical components, posing a safety risk of surface micro-cracks or localized deformation. Secondly, the application scope of current pressure controllers is limited; existing products only support basic pressure output settings, stroke displacement display, and horizontal angle monitoring, lacking dynamic linear pressure adjustment, and thus failing to meet the diverse needs of complex optical processing technologies. Summary of the Invention

[0005] To address the aforementioned deficiencies, the present invention aims to provide a high-precision pressure controller with dynamic linear output, which is intended to solve the problems mentioned in the background art. The controller includes a hardware control module responsible for program storage, computing power provision, and multi-voltage power supply. This hardware control module stores system configuration, a force-PWM mapping table, and algorithm parameters, and provides drive voltage for the low-pressure solenoid valve, sensor, and signal amplification circuit.

[0006] The sensor acquisition module is responsible for acquiring real-time system operating status data, specifically including displacement ranging sensors;

[0007] The pneumatic drive module is responsible for converting electrical signals into mechanical pressure output, and specifically includes a push rod slider module, a pneumatic proportional valve controller, and a low-resistance compressed air cylinder.

[0008] The algorithm processing module is responsible for converting user commands into control signals to achieve dynamic linear pressure output;

[0009] The host computer interaction module serves as the system's visual interaction interface.

[0010] The communication transmission module is responsible for the exchange of instructions and data between the upper and lower level computers;

[0011] The safety protection module is responsible for handling abnormal operating conditions and structural safety.

[0012] Furthermore, the low-resistance compressed air cylinder is mounted on the overall device of the pressure control system. The output end of the low-resistance compressed air cylinder is connected to an external fixed device through a bottom adapter plate. A linear guide rail is provided on the fixed device, and the overall device is slidably connected to the linear guide rail of the fixed device.

[0013] The push rod slider module includes a slider that is slidably connected on a linear guide rail, that is, the whole device is installed on the slider. The low-resistance compressed air cylinder at the back of the device is a double push cylinder, which drives the slider to complete the up and down movement.

[0014] The air pressure proportional valve controller is used to precisely regulate the intake and exhaust ratio of the two cylinders in a low-resistance compressed air cylinder. At the same time, it receives the internal pressure data of the cylinder from the sensor in real time, and dynamically adjusts the intake flow rate by calculation to achieve precise and linear control of the air pressure during repeated filling and emptying of the cylinder, ensuring pressure balance between the two cylinders.

[0015] Furthermore, the algorithm processing module specifically includes:

[0016] Linear mapping control unit: Converts input force values ​​into corresponding PWM values ​​through a predefined force-PWM mapping table, and automatically calculates based on device parameters according to the force value range;

[0017] Weighing mode unit: It initializes to zero, gradually increases the PWM value and monitors the displacement in real time. When the displacement exceeds the threshold, it records the current PWM value as the output weighing result.

[0018] Step control unit: It adopts configurable step interval and step percentage, and gradually adjusts the PWM value through timer to divide the target pressure into multiple progressive adjustments;

[0019] Displacement monitoring unit: Converts the raw displacement value collected by the sensor into the actual displacement via ADC, compares it with the set threshold, and triggers an alarm when the threshold is exceeded.

[0020] Furthermore, the force-PWM mapping table contains the correspondence between the target force value for grinding the workpiece set by the administrator, the overall weight of the equipment itself, and the cylinder air pressure output.

[0021] Furthermore, the linear mapping control unit uses a predefined force-PWM mapping table, combined with multi-dimensional parameters such as the overall weight of the equipment, cylinder air pressure output, effective stroke distance, slider reciprocating frequency, effective force-bearing area of ​​the cylinder, gravity compensation coefficient, and dynamic friction correction coefficient, to convert the user-set target force value into a precise PWM signal through multi-level calculations.

[0022] Furthermore, the calculation process is as follows:

[0023] Calculate the original theoretical thrust F output by the cylinder based on the cylinder pressure and effective force-bearing area. L :

[0024] ;

[0025] Where P is the cylinder output air pressure, in MPa; S is the effective force-bearing area of ​​the cylinder, in mm. 2 ;

[0026] Combining the equipment's own weight and gravity compensation coefficient, the formula for eliminating the offsetting / superimposed effects of the equipment's own weight on the grinding head pressure is as follows:

[0027] ;

[0028] Where: g is the acceleration due to gravity, with a value of 9.8 m / s². 2 ; , is the gravity compensation coefficient, with a value of 0.95-1.05, calibrated according to the installation tilt angle; G is the overall self-weight of the equipment, obtained through actual measurement by the weighing mode unit;

[0029] By combining real-time travel distance and reciprocating motion frequency, dynamic friction and inertia correction are introduced to counteract resistance and inertial interference during motion. The formula is as follows:

[0030] ;

[0031] in: This is the dynamic friction correction coefficient, ranging from 0.98 to 1.02, calibrated according to the friction characteristics of the guide rail; is the motion inertia correction coefficient, which is positively correlated with stroke and frequency, and ranges from 0.95 to 1.05; L is the real-time effective stroke distance of the cylinder, in mm, which is collected in real time by the displacement sensor; f is the reciprocating motion frequency of the slider, in Hz, which is preset by the user or automatically matched by the system.

[0032] The inertia correction factor is:

[0033] ;

[0034] The dynamically corrected pressure is compared with the user-set target force value, and the actual output pressure F is obtained through closed-loop verification. The formula is:

[0035] ;

[0036] in The accuracy compensation value is ±0.05N, which is automatically matched by the system's feedforward compensation.

[0037] Finally, substituting the actual effective pressure F into the pre-stored mapping function, we convert it into the PWM signal driving the pneumatic proportional valve, as shown in the formula:

[0038] ;

[0039] Where: K is the calibration scaling factor. B is the maximum output force of the cylinder, and B is the circuit zero-drift compensation bias.

[0040] Furthermore, the weighing mode unit is also used to measure the overall mass of the equipment and to reverse-optimize the force-PWM mapping table;

[0041] The system first performs an initialization and zeroing operation, measures the overall mass of the equipment, and clears the current displacement and pressure references; it gradually increases the PWM output value while monitoring the displacement sensor data in real time; when the displacement exceeds the preset threshold, it determines that the grinding head is in contact with the support surface, records the current PWM value and the corresponding air pressure, and calculates the relationship between the overall mass of the equipment and the air pressure output value by combining mechanical formulas. Finally, it updates the measured equipment mass to the force-PWM mapping table and corrects the gravity compensation parameters.

[0042] Furthermore, the host computer interaction module includes a real-time visualization unit;

[0043] Specifically, a dynamic scrolling chart is used to display historical data of PWM and displacement, which is used to observe the pressure change trend and system operating status.

[0044] Furthermore, the safety protection module integrates displacement limit alarm function and emergency stop;

[0045] When the displacement sensor detects that the stroke exceeds the preset range, it immediately controls the air output to move the device output port away from the workpiece.

[0046] The beneficial effects of this invention are as follows:

[0047] 1. By using a step control algorithm to break down the target pressure into progressive adjustments, combined with sampling period and feedforward compensation, the instantaneous impact caused by direct pressure application by traditional controllers is avoided, effectively protecting brittle optical components and reducing the risk of processing damage.

[0048] 2. A force-PWM mapping model was established, which includes multiple parameters such as equipment weight, cylinder pressure, stroke distance, and motion frequency. Through gravity compensation, dynamic friction and inertia correction calculations, the pressure error of the grinding head acting on the workpiece is controlled within ±0.05N, meeting the high-precision requirements of micro-force control in optical processing.

[0049] 3. The integrated weighing mode can automatically detect the overall mass of the equipment and optimize the force-PWM mapping table. It also supports functions such as displacement monitoring, data visualization, and manual / automatic mode switching, which expands the application scenarios of the equipment and solves the problem of the single function of the existing controller.

[0050] 4. The dual-push cylinder and slide rail limit design avoids damage to the air pipe rod caused by rapid reciprocating motion, extending the service life of the equipment; at the same time, it integrates displacement limit alarm and physical emergency stop functions, which can quickly cut off the air circuit and move the grinding head away from the workpiece under abnormal working conditions, ensuring the safety of the equipment and the workpiece.

[0051] 5. Using USB serial communication instead of network port control avoids resource consumption and electromagnetic interference, adapts to various hardware environments such as low-configuration computers, simplifies communication settings, and improves system deployment flexibility and anti-interference capabilities.

[0052] 6. Based on the host computer interface, parameter setting, real-time data display and curve plotting are realized. At the same time, data storage and historical query are supported, which facilitates process optimization and fault diagnosis and improves equipment utilization efficiency. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the device's operating principle.

[0054] Figure 2 This is a frontal view of the device;

[0055] Figure 3 This is a rear view of the device;

[0056] In the diagram: 1-Air tube; 2-Pneumatic quick connector; 3-Displacement sensor; 4-Optical isolation sensor; 5-Input port; 6-Connector board; 7-Cylinder. Detailed Implementation

[0057] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0058] It should be noted that, in the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0059] Furthermore, in the description of this invention, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0061] See Figure 1-3 The purpose of this invention is to provide a high-precision pressure controller with dynamic linear output. In general, this pressure controller achieves smooth linear control of pressure during optical processing through hardware and software collaboration, while simultaneously enabling real-time displacement monitoring and providing abundant functional expansion ports and stable communication compatibility. This addresses the problems of high impact risk, limited functionality, and insufficient versatility in existing technologies.

[0062] The core of this system relies on the STM32F1 integrated controller, low-resistance cylinder slider module, stepping force balance algorithm and USB serial communication to complete closed-loop control from command input, signal conversion, air path drive to status feedback, and finally achieve high-precision, shock-free pressure output in the range of 0–225N.

[0063] It should be explained that this invention uses a "stepping control algorithm" to avoid the impact of sudden pressure changes on optical components. By using configurable step intervals and step percentages, the target PWM value is divided into multiple progressive adjustments. Combined with a 10ms sampling period and feedforward compensation, a smooth pressure transition is achieved. At the same time, this invention uses a "displacement monitoring and alarm" mechanism. Through a high-resolution displacement sensor, the actuator stroke is collected in real time. Once it exceeds a preset threshold, a visual alarm is triggered to ensure the safety of the equipment and the workpiece.

[0064] Secondly, this invention employs a "force-PWM nonlinear mapping" mechanism. Through a pre-stored force-PWM correspondence table, the target force value input by the user is accurately converted into a proportional valve control signal. Combined with a low-friction sealed cylinder and a linear guide slider module, this ensures a linear correspondence between the force output and pressure changes, meeting the precise correspondence between repeatability and minimum working pressure, thereby satisfying the micro-force control requirements of optical processing.

[0065] Therefore, at the system level, this invention provides a high-precision pressure controller with dynamic linear output, specifically including: a hardware control module, a sensor acquisition module, a gas path drive module, a core algorithm processing module, a host computer interaction module, a communication transmission module, and a safety protection module. Through the coordinated operation of these modules, the entire process from parameter setting and pressure regulation to status monitoring is achieved.

[0066] The hardware control module is the core control hub of the system. Based on the STM32F1 core board, it is responsible for program storage, computing power provision, and multi-voltage power supply. Specifically, the hardware control module integrates registers to store the program, system configuration, force-PWM mapping table, and algorithm parameters, while providing stable power to drive the low-pressure solenoid valve, sensors, and signal amplification circuits. More specifically, at the circuit level, the hardware control module integrates a DC-24V main power supply interface, a 5V-10V voltage amplification module, and an optocoupler isolation relay. It controls the pneumatic proportional valve through PWM signals and achieves safe switching of the pneumatic path through a 2-position 5-way solenoid valve, avoiding the influence of electromagnetic interference on the control signal.

[0067] The sensor acquisition module is responsible for acquiring real-time system operating status data, providing feedback for closed-loop control. The sensor acquisition module includes a displacement distance sensor, which uses a high-resolution sensor with a resolution of 0.01mm to acquire the vertical movement of the actuator in real time, accurately detecting the current position when the actuator contacts the product.

[0068] The raw sensor data is converted into actual displacement values ​​by ADC and transmitted to the algorithm processing module and the host computer interaction module for pressure regulation, displacement over-limit judgment and visualization.

[0069] The pneumatic drive module is responsible for converting electrical signals into mechanical pressure output. The pneumatic drive module includes a push rod slider module, a pneumatic proportional valve controller, and a low-resistance compressed air cylinder.

[0070] The low-resistance compressed air cylinder is mounted on the overall pressure control system. The output end of the low-resistance compressed air cylinder is connected to an external fixed device via a bottom adapter plate. The fixed device is equipped with a linear guide rail, and the entire device is slidably connected to the linear guide rail of the fixed device.

[0071] The push rod slider module includes a slider slidably connected to a linear guide rail; the entire assembly is mounted on the slider. The low-resistance compressed air cylinder at the back of the device is a double-push cylinder, which drives the slider to complete its up-and-down movement. (See appendix) Figure 2 As shown, the slide rail is mounted on the front panel; see attached diagram. Figure 3 As shown, the two push rods of the low-resistance compressed air cylinder are arranged side by side on the rear panel. They achieve synchronous movement in the front and rear clamping state through the bottom connecting block. The slide rail has a limit function to prevent damage to the air pipe pull rod by rapid reciprocating motion.

[0072] The air pressure proportional valve controller uses a low-resistance cylinder. Specifically, it precisely controls the intake and exhaust ratio of the two cylinders in the low-resistance compressed air cylinder, while simultaneously receiving real-time internal cylinder pressure data from sensors. By calculating and dynamically adjusting the intake flow rate, it achieves precise and linear control of the air pressure during repeated filling and emptying of the cylinders, ensuring pressure balance between the two cylinders and guaranteeing the synchronization and stability of the slider module's movement. It can output a maximum air pressure of 10MPa, corresponding to a maximum thrust of 225N. The low-friction sealing design ensures smooth movement, and the PWM control signal enables linear pressure regulation.

[0073] The algorithm processing module, as the core of the system's data processing, is responsible for converting user commands into precise control signals to achieve dynamic linear pressure output. Specifically, it includes:

[0074] Linear mapping control unit: Through a predefined force-PWM mapping table, the input force value is converted into the corresponding PWM value. Simultaneously, it automatically calculates based on equipment parameters according to the force range, thereby controlling the actual output and achieving a precise correspondence between force and pressure. Specifically, the force-PWM mapping table establishes the correspondence between the target force value for grinding the workpiece set by the administrator, the overall weight of the equipment, and the cylinder air pressure output.

[0075] More specifically, the force-PWM mapping table includes the input force value, pre-entered or actually measured overall equipment mass data, and the mapping relationship calculation method. The input force value is the target contact force set by the user on the interface and applied to the workpiece being ground; the pre-entered or actually measured overall equipment mass data in the mapping table is used to compensate for the influence of gravity on the output force; the system substitutes the target force value and the equipment's own weight into the mapping relationship to calculate the corresponding PWM control signal, which is ultimately converted into cylinder air pressure output, ensuring that the actual force exerted by the grinding head on the workpiece precisely matches the set value.

[0076] It is worth noting that the linear mapping control unit, through a predefined force-PWM mapping table, combined with multi-dimensional parameters such as the overall weight of the equipment, cylinder air pressure output, effective stroke distance, slider reciprocating frequency, effective cylinder force-bearing area, gravity compensation coefficient, and dynamic friction correction coefficient, converts the user-set target force value into a precise PWM signal through multi-level calculations. This eliminates the interference of gravity, motion inertia, and frictional resistance on the actual output pressure, ensuring that the actual pressure of the grinding head on the workpiece is completely consistent with the set value. The following control processes are involved:

[0077] Calculate the original theoretical thrust F output by the cylinder based on the cylinder pressure and effective force-bearing area. L :

[0078] ;

[0079] Where P is the cylinder output air pressure (MPa); S is the effective force-bearing area of ​​the cylinder (mm²). 2 );

[0080] Combining the equipment's own weight and gravity compensation coefficient, the formula for eliminating the offsetting / superimposed effects of the equipment's own weight on the grinding head pressure is as follows:

[0081] ;

[0082] Where: g is the acceleration due to gravity, with a value of 9.8 m / s². 2 ; G is the gravity compensation coefficient (value 0.95-1.05, calibrated according to the installation tilt angle); G is the overall weight of the equipment, obtained by actual measurement through the weighing mode unit.

[0083] By combining real-time travel distance and reciprocating motion frequency, dynamic friction and inertia correction are introduced to counteract resistance and inertial interference during motion. The formula is as follows:

[0084] ;

[0085] in: This is the dynamic friction correction coefficient, ranging from 0.98 to 1.02, calibrated according to the friction characteristics of the guide rail; is the motion inertia correction coefficient, which is positively correlated with stroke and frequency, and ranges from 0.95 to 1.05; L is the real-time effective stroke distance of the cylinder (mm), which is collected in real time by the displacement sensor; f is the reciprocating motion frequency of the slider (Hz), which is preset by the user or automatically matched by the system.

[0086] The inertia correction factor is:

[0087] ;

[0088] The dynamically corrected pressure is compared with the user-set target force value, and the actual output pressure F is obtained through closed-loop verification. The formula is:

[0089] ;

[0090] in The accuracy compensation value (±0.05N) is automatically matched by the system's feedforward compensation.

[0091] Finally, substituting the actual effective pressure F into the pre-stored mapping function, we convert it into the PWM signal driving the pneumatic proportional valve, as shown in the formula:

[0092] ;

[0093] Where: K is the calibration scaling factor. B is the maximum output force of the cylinder (225N), and B is the circuit zero drift compensation bias.

[0094] Thus, the system uses gravity compensation and dynamic working condition correction to finally verify the real pressure, and then accurately maps it into a PWM signal. This solves the problem of pressure deviation caused by traditional controllers that only focus on stress value and air pressure and ignore multi-parameter interference, and realizes dynamic linear high-precision control of the grinding head pressure output.

[0095] Weighing mode unit: By initializing to zero, gradually increasing the PWM value and monitoring the displacement in real time, when the displacement exceeds the threshold, the current PWM value is recorded as the output weighing result, and the output force value measurement is automatically completed.

[0096] In addition, the weighing mode unit can measure the overall mass of the equipment and use this as a basis to optimize the force-PWM mapping table. During this process, the system first performs an initialization and zeroing operation, measures the overall mass of the equipment, and clears the current displacement and pressure references; it then gradually increases the PWM output value while simultaneously monitoring the displacement sensor data in real time; when the displacement exceeds a preset threshold, indicating contact between the grinding head and the support surface, it records the current PWM value and the corresponding air pressure, and uses mechanical formulas to calculate the relationship between the overall mass of the equipment and the air pressure output. Finally, it updates the measured equipment mass to the force-PWM mapping table, corrects the gravity compensation parameters, and thus improves the control accuracy of subsequent force output.

[0097] Stepping control unit: It adopts configurable step interval and step percentage, and gradually adjusts the PWM value through timer to divide the target pressure into multiple progressive adjustments, avoiding mechanical shock and ensuring the safety of optical components.

[0098] Displacement monitoring unit: Converts the raw displacement value collected by the sensor into the actual displacement via ADC, compares it with the set threshold, and triggers an alarm when the threshold is exceeded to achieve displacement limit protection.

[0099] Data persistence unit: Automatically saves user settings and the last system state, ensuring that the previous working state can be quickly restored after the system restarts.

[0100] The host computer interaction module is the system's visual interaction interface, built on the C# WinForm framework to create a Windows desktop application.

[0101] The interface is divided into a real-time data display area, a parameter setting area, a curve drawing area, and a manual / automatic control switch button. The data display area shows parameters such as displacement, pressure, and control quantity; the parameter setting area is used to configure the target position, control accuracy, response speed, etc.; the curve drawing area generates displacement-time and pressure-time curves in real time.

[0102] The host computer interaction module includes a real-time visualization unit. The real-time visualization unit uses a dynamic scrolling chart to display historical data of PWM and displacement, which makes it easy for users to observe the pressure change trend and system operating status, and assists in process optimization.

[0103] The communication transmission module is responsible for the instruction and data interaction between the upper and lower computers. The upper computer sends the target position instruction and control parameters to the STM32F1 core board (hardware control module) through the serial port based on the RS232 protocol. The core board transmits the current displacement, pressure and other status data back to the upper computer in real time, thereby adapting to various hardware environments such as low-configuration computers and improving system compatibility and deployment flexibility.

[0104] The safety protection module handles abnormal operating conditions and structural safety. It integrates displacement limit alarm and emergency stop logic: when the displacement sensor detects that the stroke exceeds the preset range, it immediately triggers a visual alarm and controls the pneumatic output, keeping the device's output port away from the workpiece. Simultaneously, the system supports a physical emergency stop button, allowing for rapid cessation of all actions in emergencies to prevent structural loosening or workpiece damage. Furthermore, the safety protection module includes a slide rail limit design and a low-friction sealing structure, further enhancing the system's durability and stability during long-term operation and ensuring continuous processing.

[0105] Example 1

[0106] See appendix Figure 2 and attached Figure 3 The entire device is mounted on a support structure. The pneumatic actuator uses a low-resistance dual-push cylinder 7 as its power source. The cylinders 7 are fixed side by side to the back panel of the device and are connected to the slider module through the bottom connecting block, driving the slider to complete the up-and-down reciprocating motion. The air pipe 1 serves as a compressed air transmission channel, which is laid inside the device and in the back area. It is quickly and sealed to the cylinders 7 through the pneumatic quick connector 2, providing a stable air supply and exhaust path for the cylinders 7. Together with the air pressure proportional valve, it achieves precise linear control of air pressure.

[0107] The sensing and detection components include a displacement sensor 3 and an optocoupler isolation sensor 4. The displacement sensor 3 is vertically mounted on the side of the device, corresponding to the position of the slider module. It can collect the movement stroke of the slider within the range of 0-20mm in real time with a resolution of 0.01mm, providing accurate feedback for pressure control and displacement over-limit judgment. The optocoupler isolation sensor 4 is integrated into the circuit area to collect switch signals and achieve electrical isolation transmission, improving the device's anti-interference capability and ensuring stable transmission of control signals.

[0108] Terminal block 6 is located in the upper part of the device, serving as the connection hub for the internal circuitry, fixing and connecting the wiring of various electrical components. Input port 5 is located next to terminal block 6, providing an interface for external power supply and control signals, enabling electrical communication between the device and external equipment, and working with the STM32F1 core board to complete command reception and status feedback. Through the above assembly layout, all components work together to achieve smooth pressure output, real-time status monitoring, and safety protection functions.

[0109] Based on the above, the present invention also discloses a high-precision pressure control method with dynamic linear output, applied to the aforementioned high-precision pressure controller with dynamic linear output. Relying on the collaboration of hardware modules and software algorithms, it achieves high-precision, shock-free linear output of 0-225N pressure in optical processing scenarios, solving the technical problems of strong impact, low accuracy, and poor compatibility in existing pressure control methods. The control method specifically includes the following steps:

[0110] S1. After system startup, basic preparations are performed, including hardware self-test, baseline zeroing, and initial parameter loading, laying the foundation for subsequent stress control. Specifically, during the self-test process:

[0111] After the system is powered on, the hardware control module drives the STM32F1 core board to perform self-tests on the DC-24V power supply circuit, displacement sensor, pneumatic proportional valve, 2-position 5-way solenoid valve, and communication serial port to confirm that each hardware module is operating normally. At the same time, the communication transmission module establishes an RS232 protocol USB serial port connection between the host computer and the core board, calibrates the communication baud rate and data transmission format, and ensures that there is no delay or interference in the transmission of commands and data between the host computer and the core board.

[0112] During this process, the sensor acquisition module drives the displacement ranging sensor to initialize, resets the internal air pressure value of the cylinder and the initial value of the PWM output, eliminates the initial power-on error, and reads the historical user parameters and force-PWM mapping table stored in the register to complete the initial parameter loading.

[0113] In addition, users can input or retrieve preset working parameters such as target grinding force, control accuracy, step interval, step percentage, and displacement limit threshold through the parameter setting area of ​​the host computer interaction module. The host computer then sends these parameters to the core algorithm processing module through the communication transmission module to complete the pre-configuration of the control parameters.

[0114] S2. The equipment optimizes the force value-PWM mapping table through self-weight detection;

[0115] This step achieves overall equipment quality detection through weighing mode, reverses the mapping table, eliminates the interference of equipment weight on pressure output, and solves the problem of pressure deviation caused by traditional control methods ignoring the influence of weight. Specifically, it includes the following sub-steps:

[0116] S2.1 The system triggers the weighing mode unit, and the system performs the displacement and pressure zeroing operation again, cuts off the air intake of the cylinder, and returns the slider to the initial position to establish the weighing benchmark; at the same time, the displacement sensor collects the slider displacement data in real time and sets the displacement contact threshold, that is, the critical value of displacement when the grinding head just contacts the support surface.

[0117] S2.2 Displacement monitoring and data recording are performed by gradually increasing pressure;

[0118] The system gradually increases the PWM output signal according to the preset step value, and slowly introduces air into the low-resistance compressed air cylinder through the air pressure proportional valve, pushing the slider to move down at a constant speed; the sensor acquisition module collects the raw displacement data in real time, converts it into the actual displacement value through ADC, and transmits it synchronously to the core algorithm processing module.

[0119] S2.3, Overall equipment mass calculation;

[0120] When the displacement sensor detects that the actual displacement exceeds the preset contact threshold and determines that the grinding head is in complete contact with the support surface, the system immediately stops pressurizing and records the current PWM value and cylinder air pressure value. Combining parameters such as the effective force-bearing area of ​​the cylinder and gravitational acceleration, the overall mass of the equipment is calculated back through mechanical calculation formulas. The specific calculation logic is consistent with the gravity compensation logic of the linear mapping control unit to ensure the accuracy of quality detection.

[0121] S2.4 Force-PWM mapping table optimization and update;

[0122] The core algorithm processing module replaces the theoretical mass data pre-entered in the force-PWM mapping table with the measured overall mass of the equipment, corrects the gravity compensation parameters and calculation coefficients in the mapping table, and completes the dynamic optimization of the mapping table. The optimized mapping table is stored in the core board register to achieve data persistence. Subsequent pressure control directly calls the optimized parameters to improve the accuracy of pressure output.

[0123] S3. Perform linear mapping calculation and analysis on the target force value;

[0124] This step utilizes an optimized mapping table and multi-dimensional device parameters to convert the target force value into a precise PWM signal through calculation, achieving a linear match between the force value and the air pressure output. Specifically, it includes the following steps:

[0125] S3.1 The system receives the target grinding force value sent by the host computer and synchronously retrieves parameters such as the optimized force value-PWM mapping table, overall equipment mass, effective force-bearing area of ​​the cylinder, real-time displacement value, and slider movement frequency to prepare for calculation.

[0126] S3.2 The system calculates the theoretical thrust of the cylinder, gravity compensation, dynamic friction and motion inertia correction, and finally calculates the actual effective pressure of the grinding head acting on the workpiece, ensuring that the theoretical output matches the actual needs.

[0127] S3.3 Based on the calculated actual effective pressure, the force value is converted into the corresponding PWM duty cycle signal through the nonlinear mapping relationship between force value and PWM. At the same time, the output parameters of the voltage amplification module are automatically matched according to the force value range to complete the accurate linear mapping from the target force value to the electronic control signal.

[0128] S4, Step-by-step smooth pressurization control steps;

[0129] This step uses progressive step control instead of the traditional direct pressure application method to eliminate the impact of sudden pressure changes on optical components and achieve smooth pressure output. Specifically, it includes the following steps:

[0130] S4.1 The stepper control unit analyzes the step interval and step percentage preset by the host computer, breaks down the target PWM value obtained in step S3 into multiple progressively increasing PWM sub-values, sets the timer trigger period, keeps it synchronized with the system sampling period, and ensures control response speed.

[0131] S4.2, PWM adjustment is performed step by step through air pressure linkage;

[0132] The system uses a timer to output progressively stronger control signals according to the split PWM sub-values. These PWM signals drive the air pressure proportional valve to synchronously regulate the intake and exhaust ratio of the cylinder. Combined with feedback data from the cylinder pressure sensor, the system dynamically adjusts the intake air flow to achieve multiple, progressively linear increases in air pressure.

[0133] Specifically, during the step pressurization process, the sensor acquisition module collects displacement and cylinder pressure data in real time and sends them back to the core algorithm processing module. The algorithm module compares the actual pressure value with the target pressure value in real time and corrects the PWM output error through a feedforward compensation algorithm to ensure that the pressurization process is stable and linear throughout without overshoot.

[0134] S5. During the above operation, the system monitors the status data throughout and displays the data.

[0135] Specifically, the system's sensor acquisition module continuously collects data such as displacement, cylinder pressure, and PWM output value. After ADC conversion and algorithm calculation, it obtains effective data such as real-time displacement value, actual output pressure value, and control quantity.

[0136] The communication transmission module uploads the processed operating data to the host computer interaction module in real time. The host computer displays various parameters through the real-time data display area, dynamically generates displacement-time and pressure-time curves in the curve plotting area, and presents PWM and historical displacement data in the form of scrolling charts in the real-time visualization unit, making it convenient for users to monitor pressure change trends.

[0137] Meanwhile, the host computer will automatically store real-time operating data, user parameters, and control logs, and support historical record queries and data export, which will facilitate subsequent process optimization and troubleshooting.

[0138] S6. Safety protection and anomaly handling;

[0139] Specific safety protection measures include displacement limit monitoring and abnormal response of device components;

[0140] The system compares the actual displacement value with the preset displacement limit threshold in real time through the displacement monitoring unit. If the displacement exceeds the threshold, an over-limit signal is immediately triggered. Upon receiving the over-limit signal, the safety protection module immediately triggers visual alarms, and simultaneously controls the solenoid valve to cut off the air intake to the cylinder, driving the slider to move upwards rapidly, moving the grinding head away from the workpiece to prevent workpiece damage and equipment structural loosening. Furthermore, in case of an emergency, the user can trigger the physical emergency stop button, immediately halting all operations and cutting off air and electrical outputs.

[0141] At the system level, the system continuously monitors the cylinder operating status and slide rail displacement. Relying on the slide rail limit design and low-friction sealing structure, it avoids damage to the air pipe tie rod by rapid reciprocating motion, ensuring the structural stability of long-term continuous operation.

[0142] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A high-precision pressure controller with dynamic linear output, characterized in that, include: The hardware control module is responsible for program storage, computing power provision, and multi-voltage power supply. The hardware control module stores system configuration, force-PWM mapping table and algorithm parameters, and provides drive voltage for low-pressure solenoid valve, sensor and signal amplification circuit; The sensor acquisition module is responsible for acquiring real-time system operating status data, specifically including displacement ranging sensors; The pneumatic drive module is responsible for converting electrical signals into mechanical pressure output, and specifically includes a push rod slider module, a pneumatic proportional valve controller, and a low-resistance compressed air cylinder. The algorithm processing module is responsible for converting user commands into control signals to achieve dynamic linear pressure output; The host computer interaction module serves as the system's visual interaction interface. The communication transmission module is responsible for the exchange of instructions and data between the upper and lower level computers; The safety protection module is responsible for handling abnormal operating conditions and structural safety.

2. The high-precision pressure controller with dynamic linear output according to claim 1, characterized in that, The low-resistance compressed air cylinder is mounted on the overall device of the pressure control system. The output end of the low-resistance compressed air cylinder is connected to an external fixed device through a bottom adapter plate. A linear guide rail is provided on the fixed device, and the overall device is slidably connected to the linear guide rail of the fixed device. The push rod slider module includes a slider that is slidably connected on a linear guide rail, that is, the whole device is installed on the slider. The low-resistance compressed air cylinder at the back of the device is a double push cylinder, which drives the slider to complete the up and down movement. The air pressure proportional valve controller is used to precisely regulate the intake and exhaust ratio of the two cylinders in a low-resistance compressed air cylinder. At the same time, it receives the internal pressure data of the cylinder from the sensor in real time, and dynamically adjusts the intake flow rate by calculation to achieve precise and linear control of the air pressure during repeated filling and emptying of the cylinder, ensuring pressure balance between the two cylinders.

3. The high-precision pressure controller with dynamic linear output according to claim 1, characterized in that, The algorithm processing module specifically includes: Linear mapping control unit: Converts input force values ​​into corresponding PWM values ​​through a predefined force-PWM mapping table, and automatically calculates based on device parameters according to the force value range; Weighing mode unit: It initializes to zero, gradually increases the PWM value and monitors the displacement in real time. When the displacement exceeds the threshold, it records the current PWM value as the output weighing result. Step control unit: It adopts configurable step interval and step percentage, and gradually adjusts the PWM value through timer to divide the target pressure into multiple progressive adjustments; Displacement monitoring unit: Converts the raw displacement value collected by the sensor into the actual displacement via ADC, compares it with the set threshold, and triggers an alarm when the threshold is exceeded.

4. The high-precision pressure controller with dynamic linear output according to claim 3, characterized in that, The force-PWM mapping table contains the correspondence between the target force value for grinding the workpiece set by the administrator, the overall weight of the equipment, and the cylinder air pressure output.

5. The high-precision pressure controller with dynamic linear output according to claim 4, characterized in that, The linear mapping control unit uses a predefined force-PWM mapping table, combined with multi-dimensional parameters such as the overall weight of the equipment, cylinder air pressure output, effective stroke distance, slider reciprocating frequency, effective force-bearing area of ​​the cylinder, gravity compensation coefficient, and dynamic friction correction coefficient, to convert the user-set target force value into a precise PWM signal through multi-level calculations.

6. The high-precision pressure controller with dynamic linear output according to claim 5, characterized in that, The calculation process is as follows: Calculate the original theoretical thrust F output by the cylinder based on the cylinder pressure and effective force-bearing area. L : ； Where P is the cylinder output air pressure, in MPa; S is the effective force-bearing area of ​​the cylinder. Combining the equipment's own weight and gravity compensation coefficient, the formula for eliminating the offsetting / superimposed effects of the equipment's own weight on the grinding head pressure is as follows: ； Where: g is the acceleration due to gravity, with a value of 9.8 m / s². 2 ; is the gravity compensation coefficient, calibrated according to the installation tilt angle; G is the overall weight of the equipment, obtained through actual measurement by the weighing mode unit. By combining real-time travel distance and reciprocating motion frequency, dynamic friction and inertia correction are introduced to counteract resistance and inertial interference during motion. The formula is as follows: ； in: This is the dynamic friction correction coefficient, calibrated based on the friction characteristics of the guide rail; is the motion inertia correction coefficient, which is positively correlated with stroke and frequency; L is the real-time effective stroke distance of the cylinder, which is collected in real time by the displacement sensor; f is the frequency of the slider's up-and-down reciprocating motion, which is preset by the user or automatically matched by the system. The inertia correction factor is: ； The dynamically corrected pressure is compared with the user-set target force value, and the actual output pressure F is obtained through closed-loop verification. The formula is: ； in The accuracy compensation value is automatically matched by the system's feedforward compensation. Finally, substituting the actual effective pressure F into the pre-stored mapping function, we convert it into the PWM signal driving the pneumatic proportional valve, as shown in the formula: ； Where: K is the calibration scaling factor. B is the maximum output force of the cylinder, and B is the circuit zero-drift compensation bias.

7. The high-precision pressure controller with dynamic linear output according to claim 3, characterized in that, The weighing mode unit is also used to measure the overall mass of the equipment and to reverse optimize the force-PWM mapping table. The system first performs an initialization and zeroing operation, measures the overall mass of the equipment, and clears the current displacement and pressure references; it then gradually increases the PWM output value while monitoring the displacement sensor data in real time. When the displacement exceeds the preset threshold, it is determined that the grinding head is in contact with the support surface. The current PWM value and the corresponding air pressure are recorded. The relationship between the overall mass of the equipment and the air pressure output is calculated by combining the mechanical formula. Finally, the measured mass of the equipment is updated to the force-PWM mapping table, and the gravity compensation parameters are corrected.

8. The high-precision pressure controller with dynamic linear output according to claim 1, characterized in that, The host computer interaction module includes a real-time visualization unit; Specifically, a dynamic scrolling chart is used to display historical data of PWM and displacement, which is used to observe the pressure change trend and system operating status.

9. The high-precision pressure controller with dynamic linear output according to claim 1, characterized in that, The safety protection module integrates displacement limit alarm function and emergency stop function; When the displacement sensor detects that the stroke exceeds the preset range, it immediately controls the air output to move the device output port away from the workpiece.

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