High-precision pressure control system

Abstract

The invention relates to the technical field of servo constant force control systems, in particular to a high-precision pressure control system which comprises a control unit, a driving unit, a servo motor, a force transmission unit and a force detection unit. The control unit generates a control instruction based on a preset deceleration force threshold value and an end point deceleration force threshold value according to the comparison result of the actual contact force fed back by the force detection unit and the deceleration force threshold value and the comparison result of the difference value of a preset target force set value and the actual contact force and the end point deceleration force threshold value. The driving unit responds to a control instruction and drives the servo motor to be switched among the idle stroke speed, the force application speed and the end point speed, so that impact, overshoot and oscillation on a workpiece are effectively avoided, and the stability of the force application process and the control precision of a final force value are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of servo constant force control system technology, and more specifically to a high-precision pressure control system. Background Technology

[0002] Servo constant force control system is a high-precision force control device that is widely used in industrial scenarios that require precise force adjustment, such as precision manufacturing, material testing, automated assembly and semiconductor packaging. It allows the system to accurately control the force applied to the load by manually setting the target force, idle speed, applied force speed and speed when approaching the target force on the operation screen.

[0003] However, existing force control systems typically rely on simple closed-loop PID control, adjusting the drive motor output based on the difference between the force sensor feedback and the target value. While these systems can achieve basic force control functions, they often face problems in the dynamic phase of the force application process, especially during the rapid approach to the workpiece from idle stroke to final stabilization at the target force. These problems include abrupt speed switching, overshoot or oscillation when approaching the target, and insufficient adaptability to workpieces of different materials, affecting production cycle time and accuracy. Furthermore, after long-term operation, the static errors caused by mechanical wear or environmental changes lack a simple and effective online compensation mechanism, leading to accuracy drift and requiring manual calibration after shutdown, reducing equipment utilization and automation levels. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a high-precision pressure control system to improve control accuracy.

[0005] To achieve the above objectives, the present invention provides the following technical solution: This invention provides a high-precision pressure control system, comprising: Control unit, drive unit, servo motor, force transmission unit, and force detection unit; The drive unit is electrically connected to the control unit and the servo motor respectively; The output shaft of the servo motor is connected to the input end of the force transmission unit, and the force detection unit is communicatively connected to the control unit. The control unit generates control commands based on a preset deceleration force threshold and an endpoint deceleration force threshold, according to the comparison result between the actual contact force fed back by the force detection unit and the deceleration force threshold, and the comparison result between the difference between the preset target force setting value and the actual contact force and the endpoint deceleration force threshold. The drive unit responds to control commands and drives the servo motor to switch between idle speed, applied speed and end speed.

[0006] In some embodiments, the comparison result between the actual contact force fed back by the force detection unit and the deceleration force threshold specifically includes: When the actual contact force is less than the deceleration force threshold, the servo motor is controlled to run at the idle speed. When the actual contact force is greater than or equal to the deceleration force threshold, and the difference between the target force setting and the actual contact force is greater than the endpoint deceleration force threshold, the servo motor is controlled to run at the force application speed.

[0007] In some embodiments, the comparison result of the difference between the preset target force setting value and the actual contact force and the endpoint deceleration force threshold specifically includes: When the difference between the target force setting value and the actual contact force is less than or equal to the endpoint deceleration force threshold, the servo motor is controlled to run at the endpoint speed.

[0008] In some embodiments, the idle travel speed is greater than the applied force speed, and the applied force speed is greater than the endpoint speed.

[0009] In some embodiments, an operation unit is further included, which is signal-connected to the control unit and is provided with a lift button and a pressure application button.

[0010] In some embodiments, when the control unit receives a lift command from the lift button, it controls the servo motor to move the force-applying end of the force transmission unit to a preset lift height at a preset lift speed.

[0011] In some embodiments, when the control unit receives a force application command from the pressure application button, it controls the drive unit to respond to the control command to perform a force application operation.

[0012] In some embodiments, when the control unit performs the force application operation, it dynamically compensates the target force setting value according to a preset force compensation value.

[0013] In some embodiments, the operation unit includes an electronic screen, which is further provided with a parameter configuration button for setting at least one of the target force setting value, the idle travel speed, the applied force speed, the endpoint speed, the deceleration force threshold, the endpoint deceleration force threshold, the lifting height, the lifting speed, and the force compensation value.

[0014] In some embodiments, the force transmission unit is a ball screw device.

[0015] Furthermore, the beneficial effects of the present invention are as follows: This invention features a force application device equipped with a control unit and a dual-threshold comparison mechanism based on a deceleration force threshold and a final deceleration force threshold. The device generates control commands based on the comparison results and implements servo motor control based on these commands. This device can descend rapidly with high efficiency before contacting the workpiece, smoothly decelerate to enter the precise force application stage upon initial contact with the workpiece, and fine-tune at extremely low speeds when the force value approaches the target. This effectively avoids impact, overshoot, and oscillation on the workpiece, significantly improving the stability of the force application process and the control accuracy of the final force value. Attached Figure Description

[0016] Figure 1 The overall framework diagram of the high-precision pressure control system provided by the present invention.

[0017] In the diagram: 1-Operating unit, 2-Control unit, 3-Drive unit, 4-Force transmission unit, 5-Servo motor, 6-Force detection unit, 7-Force application end. Detailed Implementation

[0018] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. In the description of the embodiments of the present invention, unless otherwise stated, " / " means "or", for example, A / B can mean A or B; "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships, for example, A and / or B can mean: A alone, A and B simultaneously, and B alone. In addition, in the description of the embodiments of the present invention, "multiple" means two or more. Hereinafter, the terms "first" and "second" are used for descriptive purposes only and should not be construed as implying or suggesting relative importance or implicitly indicating the number of indicated technical features. Thus, features defined with "first" and "second" can explicitly or implicitly include one or more of that feature. In the description of the embodiments of the present invention, unless otherwise stated, "multiple" means two or more.

[0019] like Figure 1 As shown, the present invention provides a high-precision pressure control system, comprising: Control unit 2, drive unit 3, servo motor 5, force transmission unit 4, and force detection unit 6; Among them, the drive unit 3 is electrically connected to the control unit 2 and the servo motor 5 respectively; The output shaft of the servo motor 5 is connected to the input end of the force transmission unit 4, and the force detection unit 6 is communicatively connected to the control unit 2; Based on the preset deceleration force threshold and the endpoint deceleration force threshold, the control unit 2 generates control commands according to the comparison results of the actual contact force and the deceleration force threshold fed back by the force detection unit 6, and the comparison results of the difference between the preset target force setting value and the actual contact force and the endpoint deceleration force threshold. The drive unit 3 responds to the control command and drives the servo motor 5 to switch between idle speed, applied speed and end speed.

[0020] In this embodiment, the target force setting range is 15-25 kg, with 20 kg being preferred. The deceleration force threshold is set to 1 kg, but the user can adjust the deceleration force appropriately according to the sensitivity of the workpiece or the material properties to ensure that the force application device does not generate a violent impact during the contact process.

[0021] The default idle travel speed is 2000um / s. However, for some applications that require rapid displacement, a higher speed can be set to improve operating efficiency. But if the workpiece is fragile or requires special care, this speed can be appropriately reduced to avoid damage.

[0022] The default force application speed is 10um / s to ensure a smooth force application process and prevent excessively rapid pressure changes. For precision control applications, such as material testing or pressure testing, a lower force application speed helps improve the accuracy of the results.

[0023] The default end velocity is set to 0.25um / s. With the above design, the system can achieve the target force more accurately and avoid force application errors caused by excessive speed. For applications with high precision requirements, it is recommended to set the end velocity as low as possible to ensure maximum accuracy.

[0024] One possible implementation involves comparing the actual contact force with the deceleration force threshold fed back by the force detection unit 6, specifically including: When the actual contact force is less than the deceleration force threshold, control the servo motor 5 to run at the idle stroke speed; When the actual contact force is greater than or equal to the deceleration force threshold, and the difference between the target force setting value and the actual contact force is greater than the endpoint deceleration force threshold, the servo motor 5 is controlled to run at the force application speed. In this embodiment, the deceleration force threshold of the present invention is 0.4 kg. When the system approaches the target force, by adjusting the endpoint deceleration force, it can ensure that the equipment gradually decelerates before the applied force reaches the target value, thereby reducing the impact on the workpiece or equipment and improving accuracy.

[0025] In some embodiments, the comparison result between the difference between the preset target force setting value and the actual contact force and the endpoint deceleration force threshold specifically includes: When the difference between the target force setting value and the actual contact force is less than or equal to the endpoint deceleration force threshold, the servo motor 5 is controlled to run at the endpoint speed.

[0026] In one possible implementation, the idle travel speed is greater than the applied force speed, and the applied force speed is greater than the final speed.

[0027] In one possible implementation, an operation unit 1 is further included. The operation unit 1 is signal-connected to the control unit 2 and is equipped with a lift button and an apply pressure button. The operation unit 1 includes an electronic screen, which is also equipped with a parameter configuration button for setting at least one of the following: target force setting value, idle stroke speed, applied force speed, end point speed, deceleration force threshold, end point deceleration force threshold, lift height, lift speed, and force compensation value. With the above design, the present invention provides users with a clear and intuitive one-click operation interface, encapsulating complex multi-stage control logic behind simple button instructions, greatly reducing the difficulty of system operation and the risk of misoperation, and improving the user-friendliness of human-machine interaction and the automation level of the entire process.

[0028] In one possible implementation, when the control unit 2 receives a lift command from the lift button, it controls the servo motor 5 to move the force-applying end 7 of the force transmission unit 4 to a preset lift height at a preset lift speed. This ensures the consistency and repeatability of each lift action, avoids the uncertainty that may be caused by manual operation, and improves production cycle and operational safety.

[0029] In one possible implementation, when the control unit 2 receives a force application command from the pressure application button, the control drive unit 3 responds to the control command to perform the force application operation.

[0030] In one possible implementation, when the control unit 2 performs the force application operation, it dynamically compensates the target force setting value according to the preset force compensation value. This function can correct the static error of the system caused by factors such as mechanical wear, temperature drift, and long-term creep in real time online, so that the output force value is kept in a state of high consistency with the setting value for a long time. This significantly reduces the frequency of calibration and maintenance required by the equipment due to accuracy drift and improves the long-term operational stability and reliability of the equipment.

[0031] In one possible implementation, the force transmission unit 4 is a ball screw device.

[0032] The specific embodiments of the present invention will be described in detail below with reference to specific implementation methods: Before use, the operator should first check whether the connecting cables between the electrical devices are intact. After the check is completed, turn on the system power and start the control unit 2. Wait for the main operation interface to be displayed on the electronic screen. However, it is worth noting that if this is the first use or if parameters need to be adjusted, the operator needs to click the parameter configuration button to enter the parameter setting interface and input or adjust various control parameters through the electronic screen. Again, the specific values ​​mentioned below are only one embodiment of the present invention and are not constant numerical parameters of the present invention. For example: set the deceleration force threshold to 1kg, the target force setting value to 20kg, the idle stroke speed to 2000um / s, the force application speed to 10um / s, the endpoint speed to 0.25um / s, the endpoint deceleration force threshold to 0.4kg, the lifting height to 15000um, the lifting speed to 2000um / s, and the force compensation value to 0 or a specific correction value according to the system status. Confirm that the cancel force compensation function is in the off state. At this time, the parameter setting is completed.

[0033] When a force application operation is required, the operator manually clicks the lift button. The control unit 2 receives the lift command from the button and then controls the drive unit 3 to drive the servo motor 5 to run at a preset lift speed of 2000um / s, causing the force application end 7 of the ball screw device to move upward until it reaches a preset lift height of 15000um and stops, leaving space for the workpiece. The operator places the workpiece to be pressurized directly below the force application end 7 of the force transmission unit 4 and then clicks the apply pressure button. The control unit 2 receives the force application command and first controls the drive unit 3 to drive the servo motor 5 to quickly descend at the idle stroke speed. At the same time, during the descent, the force detection unit 6 detects the actual contact force between the force application end 7 and the workpiece in real time and feeds it back to the control unit 2. The control unit 2 compares the actual contact force with the preset deceleration force threshold.

[0034] When the actual contact force is less than the threshold, the servo motor 5 maintains its idle speed. When the actual contact force is greater than the threshold, the control unit 2 determines that it has contacted the workpiece and generates a control command. The drive unit 3 responds to the command by switching the servo motor 5 to a lower force application speed to continue applying pressure downwards. At the same time, the control unit 2 calculates the difference between the preset target force setting and the actual contact force and compares this difference with the preset endpoint deceleration force threshold. When the difference is greater than the endpoint deceleration force threshold, the system maintains the force application speed. As the pressure increases, when the difference decreases to be equal to or less than the endpoint deceleration force threshold, the control unit 2 determines that it is very close to the target force and generates another control command. The drive unit 3 drives the servo motor 5 to switch to an extremely low endpoint speed and slowly descends for final fine-tuning of the pressure until the actual contact force reported by the force detection unit 6 stabilizes at the target force value of 20 kg. At this point, the control unit 2 can control the servo motor 5 to stop or enter a force holding mode.

[0035] However, it should be noted that if the force compensation function is activated during the entire force application process, the control unit 2 will also dynamically compensate the target force setting value according to the preset force compensation value to offset any static deviations that may exist in the system and ensure that the applied force value is accurate and stable over a long period of time.

[0036] After the force application task is completed, the lifting button can be clicked again to raise the force application end 7 to a safe height and remove the workpiece, thus completing a complete work cycle. Throughout the process, the display box on the electronic screen updates the current force value in real time for the operator to monitor.

[0037] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A high precision pressure control system, characterized by, include: Control unit, drive unit, servo motor, force transmission unit, and force detection unit; The drive unit is electrically connected to the control unit and the servo motor respectively; The output shaft of the servo motor is connected to the input end of the force transmission unit, and the force detection unit is communicatively connected to the control unit. The control unit generates control commands based on a preset deceleration force threshold and an endpoint deceleration force threshold, according to the comparison result between the actual contact force fed back by the force detection unit and the deceleration force threshold, and the comparison result between the difference between the preset target force setting value and the actual contact force and the endpoint deceleration force threshold. The drive unit responds to control commands and drives the servo motor to switch between idle speed, applied speed and end speed.

2. The high precision pressure control system of claim 1, wherein, The comparison result between the actual contact force fed back by the force detection unit and the deceleration force threshold specifically includes: When the actual contact force is less than the deceleration force threshold, the servo motor is controlled to run at the idle speed. When the actual contact force is greater than or equal to the deceleration force threshold, and the difference between the target force setting and the actual contact force is greater than the endpoint deceleration force threshold, the servo motor is controlled to run at the force application speed.

3. The high precision pressure control system of claim 1, wherein, Based on the comparison result of the difference between the preset target force setting value and the actual contact force and the endpoint deceleration force threshold, specifically including: When the difference between the target force setting value and the actual contact force is less than or equal to the endpoint deceleration force threshold, the servo motor is controlled to run at the endpoint speed.

4. The high precision pressure control system of claim 3, wherein, The idle travel speed is greater than the applied force speed, and the applied force speed is greater than the endpoint speed.

5. The high precision pressure control system of claim 1, wherein, It also includes an operation unit, which is signal-connected to the control unit and is equipped with a lift button and a pressure application button.

6. The high precision pressure control system of claim 5, wherein, When the control unit receives a lift command from the lift button, it controls the servo motor to move the force-applying end of the force transmission unit to a preset lift height at a preset lift speed.

7. The high precision pressure control system of claim 5, wherein, When the control unit receives a force application command from the pressure application button, it controls the drive unit to respond to the control command and perform the force application operation.

8. The high precision pressure control system of claim 7, wherein, When the control unit performs the force application operation, it dynamically compensates the target force setting value according to the preset force compensation value.

9. The high precision pressure control system of claim 8, wherein, The operation unit includes an electronic screen, which is also equipped with a parameter configuration button for setting at least one of the target force setting value, the idle travel speed, the applied force speed, the endpoint speed, the deceleration force threshold, the endpoint deceleration force threshold, the lifting height, the lifting speed, and the force compensation value.

10. The high precision pressure control system of claim 1, wherein, The force transmission unit is a ball screw device.

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