Method and system for controlling constant line pressure of a horizontal cylinder reel

Abstract

This application relates to a method and system for controlling constant linear pressure in a horizontal cylindrical paper winding machine, belonging to the field of paper machinery automation control technology. The method includes: acquiring real-time rotation angle data of the secondary arm of the paper winding machine; converting the real-time rotation angle data into real-time roll diameter data of the paper roll based on a preset eccentric crank-slider displacement geometric model; calculating and obtaining the target cylinder supply pressure based on a torque balance mechanical model of the secondary arm according to a preset target constant linear pressure and the real-time roll diameter data; generating a control command based on the target cylinder supply pressure, and adjusting the actual supply pressure of the pressurizing cylinder through an electro-proportional valve. This application overcomes the problem of linear pressure fluctuation caused by traditional constant pressure control by constructing a geometric and mechanical coupling model, realizing dynamic control of constant linear pressure across the entire roll diameter range, avoiding defects such as paper roll wrinkling and uneven tightness, and improving roll quality.

Description

Technical Field

[0001] This application relates to the field of papermaking machinery technology, and in particular to a method and system for controlling constant linear pressure in a horizontal cylindrical paper winding machine. Background Technology

[0002] The horizontal cylindrical paper winding machine is a key winding device at the end of the papermaking machine. Its main function is to wind a continuous paper web into a paper roll. During the winding process, the linear pressure between the paper roll and the winding cylinder is the core parameter that determines the roll tightness, finished product quality, and subsequent storage and processing performance.

[0003] Currently, in actual paper mill production, paper winding machines typically use pneumatic or hydraulic cylinders to apply clamping force, and most equipment still primarily relies on constant air or hydraulic pressure output. However, during the actual winding process, as the paper roll diameter increases, the mechanical posture of the clamping mechanism, its own weight torque, and the effective lever arm of the cylinder all undergo significant nonlinear changes. If only the air or hydraulic supply pressure to the cylinder is kept constant, it will cause drastic fluctuations in the actual linear pressure between the paper roll and the winding cylinder.

[0004] This traditional single constant pressure control method lacks flexibility and cannot maintain true constant linear pressure throughout the entire roll diameter variation process. With the increasing market demand for high-quality paper products (especially those with low basis weight and high bulk, which are highly sensitive to changes in linear pressure), traditional control methods are no longer sufficient to meet quality requirements, easily leading to quality defects such as paper roll wrinkling, uneven tension, and flaring at both ends. In actual production, frequent manual intervention and experience-based adjustments are often required, severely restricting the automation level and production stability of the winding process. Summary of the Invention

[0005] In view of the above problems, this application provides a method and system for controlling constant linear pressure in a horizontal cylindrical paper winding machine. By dynamically adjusting the cylinder air supply pressure according to the real-time roll diameter through a geometric-mechanical coupling model, the automatic control of constant linear pressure across the entire roll diameter range is realized, thereby improving the roll quality.

[0006] In a first aspect, embodiments of this application provide a method for controlling constant linear pressure in a horizontal cylindrical paper winding machine, applicable to a horizontal cylindrical paper winding machine including a secondary arm, a winding roll, and a pressurizing cylinder. The method includes the following steps: Obtain the real-time rotation angle data of the secondary arm; Based on the preset eccentric crank-slider displacement geometric model, the real-time roll diameter data of the paper roll on the paper machine is calculated according to the real-time rotation angle data. Based on the preset target constant linear pressure and the real-time roll diameter data, the target cylinder air supply pressure is calculated using the torque balance mechanical model of the secondary arm. A control command is generated based on the target cylinder's air supply pressure, and the actual air supply pressure of the pressurized cylinder is adjusted via an electric proportional valve.

[0007] Preferably, the eccentric crank-slider displacement geometric model equates the secondary arm to a crank and the displacement of the pressure roller to a slider displacement. The calculation formula for the real-time roll diameter data is as follows: Among them, L A R is the horizontal distance between the rotation hinge point of the secondary arm and the starting position of the paper roll cylinder, L is the equivalent crank radius of the secondary arm, L1 is the length of the equivalent connecting rod in the geometric model, α is the real-time rotation angle data, and e is the eccentricity of the slider displacement.

[0008] Preferably, the torque balance mechanical model takes the rotation hinge point of the secondary arm as the torque center, and the cylinder output force F corresponding to the target cylinder supply pressure is... c Determined based on the following moment balance equations: Where H is the effective lever arm of the cylinder thrust relative to the rotary hinge point, and F n R is the normal positive clamping force of the secondary arm on the paper roll, θ is the equivalent crank radius of the secondary arm, θ is the angle between the line connecting the rotation hinge point to the center of the pressure roller of the paper roll and the normal positive clamping force, β is the angle between the line connecting the rotation hinge point to the center of the paper roll and the horizontal line, G is the self-weight of the secondary arm, and h is the distance between the center of mass of the secondary arm and the rotation hinge point.

[0009] Preferably, the normal positive clamping force F n The calculation formula is: Among them, F L The target constant linear pressure is preset according to the characteristics of the paper type, b is the width of the paper roll, and γ is the angle between the normal positive pressure and the line connecting the center of the paper roll to the pivot point.

[0010] Preferably, the step of calculating the target cylinder air supply pressure includes: Based on the eccentric crank-slider displacement geometric model and the torque balance mechanical model, the corresponding values ​​of multiple paper roll diameters and target cylinder air supply pressure within the preset working range are calculated, and a roll diameter pressure lookup table is constructed. During the control process, the current target cylinder air supply pressure is determined by linear interpolation calculation based on the real-time roll diameter data in the roll diameter pressure lookup table.

[0011] Preferably, the pressurizing cylinder includes a transmission-side pressurizing cylinder and an operating-side pressurizing cylinder, and the electro-proportional valve includes a transmission-side electro-proportional valve and an operating-side electro-proportional valve; the step of adjusting the actual air supply pressure of the pressurizing cylinder through the electro-proportional valve includes: Obtain the actual air supply pressure feedback values ​​of the transmission-side pressurizing cylinder and the operation-side pressurizing cylinder collected by the pressure sensor; Receive independent pressure offset settings for the drive side and the operating side; The target cylinder air supply pressure is superimposed with the independent pressure offset setting values ​​of the transmission side and the operation side to obtain the control setpoint. Based on the actual gas supply pressure feedback value, the transmission-side electro-proportional valve and the operating-side electro-proportional valve are used to perform closed-loop pressure regulation on the transmission-side pressurization cylinder and the operating-side pressurization cylinder, respectively.

[0012] Preferably, before the step of acquiring the real-time rotation data of the secondary arm, the method further includes: The secondary arm is controlled to move closer to the paper roll cylinder, and the rotation angle data of the secondary arm is monitored in real time. When the rotation angle data reaches a preset angle threshold, it is determined that the secondary arm has pressed the paper roll, and the step of obtaining the real-time rotation angle data of the secondary arm is triggered.

[0013] Secondly, embodiments of this application provide a control system for constant linear pressure in a horizontal cylindrical paper winding machine, used to implement the control method described in any embodiment of the first aspect, including: An angle acquisition module is used to acquire the real-time rotation angle data of the secondary arm; The controller is communicatively connected to the angle acquisition module. The controller is configured to: calculate the real-time roll diameter data of the paper roll on the paper machine based on the real-time rotation angle data according to a preset eccentric crank-slider displacement geometric model; calculate the target cylinder supply pressure based on the torque balance mechanical model of the secondary arm according to the preset target constant linear pressure and the real-time roll diameter data; and generate control commands according to the target cylinder supply pressure. The pressure execution module is communicatively connected to the controller. The pressure execution module includes an electro-proportional valve for adjusting the actual air supply pressure of the pressurizing cylinder according to the control command.

[0014] Preferably, the pressure execution module further includes a pressure sensor, the control terminal of the electro-proportional valve is electrically connected to the controller, the output terminal of the electro-proportional valve is connected to the air circuit of the pressurizing cylinder, and the pressure sensor is set in the air intake circuit of the pressurizing cylinder and connected to the controller for feedback, for collecting the actual air supply pressure feedback value of the pressurizing cylinder.

[0015] Preferably, the pressurizing cylinder includes a drive-side pressurizing cylinder and an operating-side pressurizing cylinder, and the electro-proportional valve includes a drive-side electro-proportional valve and an operating-side electro-proportional valve; the controller is further configured to: receive independent pressure offset setpoints from the drive side and the operating side; superimpose the target cylinder supply pressure with the independent pressure offset setpoints from the drive side and the operating side respectively to obtain a control setpoint; and, in conjunction with the actual supply pressure feedback value, independently send control commands to the drive-side electro-proportional valve and the operating-side electro-proportional valve to perform closed-loop pressure regulation on the drive-side pressurizing cylinder and the operating-side pressurizing cylinder respectively.

[0016] The method and system for controlling constant linear pressure in a horizontal cylindrical paper winding machine provided in this application obtains the nonlinear analytical law of cylinder air supply pressure changing with the paper roll diameter by constructing a coupling relationship between an eccentric crank-slider displacement geometric model and a secondary arm torque balance mechanical model. The system calculates the current roll diameter based on real-time rotation angle data, dynamically solves for the target air supply pressure, and performs closed-loop adjustment of the pressurizing cylinder. This overcomes the linear pressure fluctuations caused by changes in the mechanism's lever arm during winding, achieving constant linear pressure control across the entire roll diameter range. This improves the uniformity of the internal density distribution of the paper roll, reduces the incidence of winding defects such as wrinkling, and enhances the final roll quality. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments of this application will be briefly described below. Obviously, the drawings described below are only for illustrating preferred embodiments and are not intended to limit the scope of this application. In the drawings: Figure 1 This is a schematic diagram of the physical structure of the paper machine pressing mechanism and its eccentric crank slider provided in the embodiments of this application.

[0018] Figure 2 This is a schematic diagram of the force analysis of the secondary arm, paper roll, and paper roll cylinder provided in the embodiments of this application.

[0019] Figure 3 This is a pneumatic schematic diagram of the constant linear pressure control system for a paper roll machine provided in an embodiment of this application.

[0020] Figure 4 This is a nonlinear relationship curve of air supply pressure versus paper roll diameter under a target constant linear pressure, provided in an embodiment of this application.

[0021] Figure 5 This is a flowchart illustrating the method for controlling constant linear pressure in a horizontal cylindrical paper winding machine according to an embodiment of this application.

[0022] The components include: 1. Electrical proportional valve; 2. Secondary arm; 3. Pressure sensor; 4. Paper roll; 5. Pressurizing cylinder; 6. Paper roll cylinder; and 10. Pressure actuation module. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0024] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0025] It should also be understood that the terminology used in this application specification is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0026] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0027] Firstly, this embodiment provides a method for controlling constant linear pressure in a horizontal cylindrical paper winding machine, applicable to such a machine. (See also...) Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, the paper winding machine mainly includes a secondary arm 2, a winding roll 4, a pressure cylinder 5, and a winding cylinder 6. During the operation of the paper winding machine, the winding cylinder 6 rotates at a constant linear speed and drives the winding roll 4 through surface friction to achieve continuous winding of the paper web. As the diameter of the paper roll increases, the posture of the secondary arm 2 deviates outward. In order to maintain a constant linear pressure between the paper roll and the winding cylinder 6 throughout the entire roll diameter range, the control method of this embodiment specifically includes the following steps: Step S1: Obtain the real-time rotation angle data of secondary arm 2.

[0028] Specifically, during the operation of the paper winding machine, an angle detection device installed at the rotary hinge shaft of the secondary arm 2 collects the deflection angle of the secondary arm 2 relative to the horizontal reference plane in real time, generating real-time rotation angle data. This real-time rotation angle data can accurately reflect the current paper roll winding progress and the geometric posture of the clamping mechanism.

[0029] Before executing step S1, to achieve automated connection of the winding process, the method of this embodiment also includes control mode initialization and automatic triggering steps. Specifically, after the roll changing action is completed, the control system drives the secondary arm 2 to move towards the paper winding cylinder 6, and simultaneously monitors the rotation angle data of the secondary arm 2 in real time. When the rotation angle data reaches a preset angle threshold, the system determines that the secondary arm 2 has stably pressed the paper winding roller 4.

[0030] In this embodiment, the preset angle threshold is set according to the actual working angle range of the paper roll machine. For example, when the paper roll diameter is at the minimum design roll diameter (e.g., 185 mm), the initial clamping angle of the secondary arm 2 is approximately 74.7 degrees; as winding progresses, the angle can reach over 90 degrees when fully wound (e.g., 1500 mm). Therefore, the preset angle threshold is set to 75 degrees. When the real-time angle reaches 75 degrees, it indicates that the secondary arm 2 has passed the initial unloaded displacement and established reliable mechanical clamping contact. After this condition is met, the DCS (Distributed Control System) automatically switches to constant linear pressure control mode and seamlessly triggers the following steps to obtain the real-time angle data of the secondary arm 2, thereby effectively avoiding control lag and operational errors caused by manual intervention.

[0031] Step S2: Based on the preset eccentric crank slider displacement geometric model, the real-time roll diameter data of the paper roll on the paper winding machine is calculated according to the real-time rotation angle data.

[0032] In specific implementation, by constructing such Figure 1 The eccentric crank-slider displacement geometric model shown is designed to avoid significant errors associated with directly measuring the diameter of a rapidly rotating and continuously increasing paper roll. In this embodiment, the geometric model physically equates the secondary arm 2 to a crank, and the center displacement of the paper roll to the crank-slider displacement S. The calculation formula is as follows: Where R is the equivalent crank radius of secondary arm 2, L1 is the length of the equivalent connecting rod in the geometric model, α is the real-time rotation angle data, and e is the eccentricity of the slider displacement.

[0033] Based on this geometric model, the real-time roll diameter data D is calculated using the following formula: Among them, L ALet R be the horizontal distance between the pivot point of the secondary arm and the starting position of the paper roll cylinder, R be the equivalent crank radius of the secondary arm, L1 be the length of the equivalent connecting rod in the geometric model, α be the real-time rotation angle data, and e be the eccentricity of the slider displacement. Through the above transformation of purely geometric relationships, the real-time roll diameter data of the current paper roll can be indirectly calculated with high precision based on a single angle variable of the secondary arm 2, and the applicable range can cover the entire design roll diameter range of the paper roll machine. In this embodiment, the roll diameter data D is applicable to secondary arm rotation angles of 68° to 98°, which can completely cover the design roll diameter range of 184 to 1500 mm of the equipment.

[0034] Step S3: Based on the preset target constant linear pressure and the real-time roll diameter data, the target cylinder air supply pressure is calculated according to the torque balance mechanical model of the secondary arm 2.

[0035] See Figure 2 , Figure 2 This is a schematic diagram of the force analysis of the secondary arm, paper roll, and paper winding cylinder provided in the embodiments of this application. In the figure, point A is the rotation hinge point of the secondary arm 2, point B is the center of mass of the secondary arm 2, point C is the connection point between the secondary arm 2 and the pressure cylinder 5, point K is the fixed hinge point of the pressure cylinder 5, point E is the center of the pressure roller of the paper winding roller 4, and point F is the center of the paper winding roller 4.

[0036] After acquiring real-time roll diameter data, since the self-weight deflection torque of secondary arm 2 at different deflection angles and the effective lever arm of pressurized cylinder 5 are both in a nonlinear dynamic state, this embodiment constructs a torque balance mechanical model with the rotation hinge point of secondary arm 2 as the torque center. The cylinder output force F corresponding to the target cylinder supply pressure... c Determined based on the following moment balance equations: Where H is the effective lever arm of the cylinder thrust relative to the rotary hinge point, and F n R is the normal positive clamping force of the secondary arm 2 on the paper roll 4, R is the equivalent crank radius of the secondary arm 2, and θ is the line connecting the rotation hinge point A to the center E of the pressure roller of the paper roll 4 and the normal positive clamping force F. n The included angle, α is the real-time rotation angle data, G is the self-weight of the secondary arm 2, and h is the distance between the center of mass B of the secondary arm 2 and the rotation hinge point A.

[0037] Furthermore, the normal positive clamping force F in the above torque balance equation... n It is not a fixed value, but is determined by the linear pressure required by the process. In this embodiment, the normal positive clamping force F n The following conversion formula is used for calculation: Among them, F LTo determine the target constant linear pressure based on the characteristics of the paper type, b is the width of the paper roll, and γ is the normal positive clamping force F. n The angle between the line connecting the center F of the paper roll 4 to the pivot point A, and β is the angle between the line connecting the pivot point A to the center F of the paper roll 4 and the horizontal line.

[0038] In this embodiment, the output force F of the pressurizing cylinder 5 c The relationship between F and the actual gas supply pressure P satisfies: c =P·S c ·η; where S c Let η be the effective working area of ​​the pressurizing cylinder 5; and η be the mechanical efficiency of the pressurizing cylinder 5. Secondly, since the rotation angle change of the secondary arm 2 during the winding process causes nonlinear changes in the effective lever arm H and the force angle β of the cylinder, this embodiment solves for the dynamic lever arm based on the geometric constraints of the mechanism. In the geometric triangle formed by the secondary arm 2, the winding roller 4, and the rotation hinge point A, the following relationship is satisfied: Within the geometric triangle formed by the secondary arm 2 and the pressurized cylinder 5, the following relationship is satisfied: Where, e is the eccentricity of the slider displacement, that is, the vertical distance from the rotation hinge point A of the secondary arm 2 to the center F of the paper roll 4; L2 is the dynamic length from the fixed hinge point K of the pressure cylinder 5 to the connection point C between the secondary arm 2 and the pressure cylinder 5; L3 is the distance from the fixed hinge point K of the pressure cylinder 5 to the rotation hinge point A of the secondary arm 2; L4 is the distance from the connection point C between the pressure cylinder 5 and the secondary arm 2 to the rotation hinge point A of the secondary arm 2; ψ is the angle between the line connecting the fixed hinge point K of the pressure cylinder 5 and the rotation hinge point A of the secondary arm 2 and the horizontal line.

[0039] By simultaneously solving the above geometric relationships and the torque balance equations, and considering that the difference between the secondary arm rotation angle α and the force angle β during the paper rolling process is extremely small, we approximate β=α, and finally obtain the composite analytical function of the target cylinder air supply pressure with respect to the paper roll diameter and the target linear pressure over the entire roll diameter: P=f(F L This composite analytical function comprehensively considers actual working conditions such as roll diameter variation, secondary arm 2 rotation angle, mechanism self-weight, and cylinder efficiency, and fully describes the quantitative mapping relationship between cylinder air supply pressure and paper roll diameter.

[0040] like Figure 4As shown, under constant linear pressure conditions, the air supply pressure exhibits a nonlinear adaptation trajectory of increasing and then decreasing with the change in paper roll diameter. Specifically, taking the target constant linear pressure of 1.5 kN / m as an example, in the small roll diameter stage (i.e., when the paper roll diameter is less than 850 mm), as the paper roll diameter increases, the outward deviation of the secondary arm's posture causes a significant increase in the resistance torque generated by its own weight. At this time, the target cylinder air supply pressure required to maintain constant linear pressure gradually increases to overcome the influence of its own weight. However, in the large roll diameter stage (i.e., when the paper roll diameter is greater than 850 mm), as the paper roll diameter continues to increase, the torque of the normal positive clamping force of the secondary arm on the paper roll roller acting on the rotation hinge point gradually decreases. At this time, the required pressurizing cylinder thrust decreases, and the target cylinder air supply pressure gradually decreases.

[0041] In some embodiments, to reduce the real-time computational load of the industrial control system and improve the response speed, the step of calculating the target cylinder supply pressure specifically adopts a combination of discrete lookup table and interpolation. Specifically, in offline mode, based on the eccentric crank-slider displacement geometric model and torque balance mechanical model, multiple paper roll diameter nodes within a preset working range and their corresponding target cylinder supply pressure values ​​are pre-calculated with a set roll diameter step size. A two-dimensional roll diameter pressure lookup table is constructed and burned into the controller's storage unit. During actual control, the controller retrieves two adjacent paper roll diameter nodes from the roll diameter pressure lookup table based on real-time roll diameter data and quickly calculates the target cylinder supply pressure currently between the two nodes using a linear interpolation algorithm. This method effectively reduces the real-time floating-point computational load of the industrial control system and improves the dynamic response speed while ensuring the accuracy of linear pressure control.

[0042] Step S4: Generate a control command based on the target cylinder supply pressure, and adjust the actual supply pressure of the pressurized cylinder 5 through the electric proportional valve 1.

[0043] Because the paper machine has a large width, the pressurizing cylinder 5 typically includes a drive-side pressurizing cylinder and an operating-side pressurizing cylinder. Correspondingly, the electro-proportional valve 1 includes a drive-side electro-proportional valve and an operating-side electro-proportional valve. To prevent defects such as flaring at both ends of the paper roll due to mechanical deviation or uneven force, the specific steps for adjusting the actual air supply pressure of the pressurizing cylinder 5 through the electro-proportional valve 1 include: First, the actual air supply pressure feedback values ​​of the transmission-side pressurizing cylinder and the operating-side pressurizing cylinder collected by pressure sensor 3 are obtained. Second, the independent pressure offset setting values ​​of the transmission side and the operating side are received. Subsequently, the target cylinder air supply pressure is superimposed with the independent pressure offset setting values ​​of the transmission side and the operating side to obtain the control setpoint. Finally, combined with the actual air supply pressure feedback value, the transmission-side pressurizing cylinder and the operating-side pressurizing cylinder are subjected to closed-loop pressure regulation through the transmission-side electro-proportional valve 1 and the operating-side electro-proportional valve 1, respectively. This control process forms a closed-loop regulation, so that the cylinder air supply pressure exhibits a non-linear adaptation trajectory of first increasing and then decreasing as the roll diameter increases, ensuring that the linear pressure finally applied to the paper roll always remains at the target constant value.

[0044] Secondly, based on the same inventive concept as in Embodiment 1, this embodiment provides a control system for constant linear pressure of a horizontal cylindrical paper winding machine, used to implement the control method of Embodiment 1. The control system mainly includes an angle acquisition module, a controller, and a pressure execution module 10 in its hardware architecture.

[0045] Specifically, the angle acquisition module is used to acquire real-time rotation angle data of the secondary arm 2. Structurally, the angle acquisition module includes an angle encoder, which is coaxially mounted on the rotary hinge shaft of the secondary arm 2 of the paper winding machine. This mounting method eliminates measurement errors caused by transmission backlash, ensuring high fidelity of the real-time rotation angle data.

[0046] The controller communicates with the angle acquisition module. The controller typically employs a programmable logic controller (PLC) or a distributed control system (DCS), internally storing a preset geometric model of the eccentric crank-slider displacement and a torque balance mechanical model of the secondary arm 2. The controller is configured to: receive real-time angle data from the angle encoder; calculate the real-time roll diameter data of the paper roll on the paper machine based on the preset geometric model of the eccentric crank-slider displacement and the real-time roll diameter data; subsequently, based on the preset target constant linear pressure and the real-time roll diameter data, and using the torque balance mechanical model of the secondary arm 2, calculate the target cylinder air supply pressure and generate corresponding control commands.

[0047] The pressure execution module 10 is communicatively connected to the controller and is used to adjust the actual air supply pressure of the pressurizing cylinder 5 according to the target cylinder air supply pressure. The pressure execution module 10 includes an electro-proportional valve 1 and a pressure sensor 3. The control terminal of the electro-proportional valve 1 is electrically connected to the controller, and the output terminal of the electro-proportional valve 1 is connected to the air circuit of the pressurizing cylinder 5. The pressure sensor 3 is installed in the air intake circuit of the pressurizing cylinder 5 and is connected to the controller for feedback, and is used to collect the feedback value of the actual air supply pressure of the pressurizing cylinder 5, thereby forming a pressure closed-loop control in the pneumatic circuit and improving the steady-state accuracy of pressure regulation.

[0048] In some embodiments, for a large-width paper roll machine, the pressurizing cylinder 5 includes a drive-side pressurizing cylinder and an operating-side pressurizing cylinder respectively disposed on the drive side and the operating side of the paper roll machine. Correspondingly, the pressure actuation module 10 includes a drive-side electro-proportional valve and an operating-side electro-proportional valve respectively connected to the air circuits of the drive-side pressurizing cylinder and the operating-side pressurizing cylinder. The controller is also configured to have a dual-side independent compensation function: receiving independent pressure offset setpoints from the drive side and the operating side, superimposing the calculated base target cylinder air supply pressure with the independent pressure offset setpoints, and combining the actual air supply pressure feedback value, independently sending control commands to the drive-side electro-proportional valve and the operating-side electro-proportional valve to perform closed-loop pressure regulation of the drive-side pressurizing cylinder and the operating-side pressurizing cylinder respectively. This structural design enables the system to not only automatically track the constant linear pressure theoretical curve, but also to accommodate manual experience-based fine-tuning, ensuring the robustness and field adaptability of the entire control system.

[0049] The method and system for controlling constant linear pressure in a horizontal cylindrical paper winding machine provided in this application obtain the nonlinear analytical law of cylinder air supply pressure changing with the paper roll diameter by constructing a coupling relationship between an eccentric crank-slider displacement geometric model and a secondary arm torque balance mechanical model. The system calculates the current roll diameter based on real-time rotation angle data, dynamically solves for the target air supply pressure, and performs closed-loop adjustment of the pressurizing cylinder. This overcomes the linear pressure fluctuations caused by changes in the mechanism's lever arm during winding, achieving constant linear pressure control across the entire roll diameter range. This improves the uniformity of the internal density distribution of the paper roll, reduces the incidence of winding defects such as wrinkling, and improves the final roll quality.

[0050] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the various examples have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this application.

[0051] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For example, the division of each unit is merely a logical functional division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed.

[0052] The steps in the methods of this application embodiment can be adjusted, merged, or deleted according to actual needs. The units in the apparatus of this application embodiment can be merged, divided, or deleted according to actual needs. Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0053] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a terminal, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application.

[0054] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for controlling constant linear pressure in a horizontal cylindrical paper winding machine, applied to a horizontal cylindrical paper winding machine, the horizontal cylindrical paper winding machine comprising a secondary arm, a winding roll, and a pressurizing cylinder, characterized in that... The method includes the following steps: Obtain the real-time rotation angle data of the secondary arm; Based on the preset eccentric crank-slider displacement geometric model, the real-time roll diameter data of the paper roll on the paper machine is calculated according to the real-time rotation angle data. Based on the preset target constant linear pressure and the real-time roll diameter data, the target cylinder air supply pressure is calculated using the torque balance mechanical model of the secondary arm. A control command is generated based on the target cylinder's air supply pressure, and the actual air supply pressure of the pressurized cylinder is adjusted via an electric proportional valve.

2. The control method according to claim 1, characterized by, The eccentric crank-slider displacement geometric model equates the secondary arm to a crank and the displacement of the pressure roller to a slider displacement. The calculation formula for the real-time roll diameter data is as follows: Among them, L A R is the horizontal distance between the rotation hinge point of the secondary arm and the starting position of the paper roll cylinder, L is the equivalent crank radius of the secondary arm, L1 is the length of the equivalent connecting rod in the geometric model, α is the real-time rotation angle data, and e is the eccentricity of the slider displacement.

3. The control method according to claim 1, characterized by, The torque balance mechanical model takes the rotation hinge point of the secondary arm as the torque center, and the cylinder output force F corresponding to the target cylinder supply pressure is... c Determined based on the following moment balance equations: Where H is the effective lever arm of the cylinder thrust relative to the rotary hinge point, and F n R is the normal positive clamping force of the secondary arm on the paper roll, θ is the equivalent crank radius of the secondary arm, θ is the angle between the line connecting the rotation hinge point to the center of the pressure roller of the paper roll and the normal positive clamping force, β is the angle between the line connecting the rotation hinge point to the center of the paper roll and the horizontal line, G is the self-weight of the secondary arm, and h is the distance between the center of mass of the secondary arm and the rotation hinge point.

4. The control method according to claim 3, characterized by The normal positive contact force F n The calculation formula is: where F L is a target constant line pressure preset according to paper properties, b is the width of the paper roll, and γ is the included angle between the normal pressing force and the line from the center of the paper roll to the turning hinge point.

5. The control method according to claim 1, characterized by, The step of calculating the target cylinder air supply pressure includes: Based on the eccentric crank-slider displacement geometric model and the torque balance mechanical model, the corresponding values ​​of multiple paper roll diameters and target cylinder air supply pressure within the preset working range are calculated, and a roll diameter pressure lookup table is constructed. During the control process, linear interpolation calculations are performed on the roll diameter pressure lookup table based on the real-time roll diameter data to determine the current target cylinder air supply pressure.

6. The control method according to claim 1, characterized by, The pressurizing cylinder includes a drive-side pressurizing cylinder and an operating-side pressurizing cylinder; the electro-proportional valve includes a drive-side electro-proportional valve and an operating-side electro-proportional valve; the step of adjusting the actual air supply pressure of the pressurizing cylinder through the electro-proportional valve includes: Obtain the actual air supply pressure feedback values ​​of the transmission-side pressurizing cylinder and the operation-side pressurizing cylinder collected by the pressure sensor; Receive independent pressure offset settings for the drive side and the operating side; The target cylinder air supply pressure is superimposed with the independent pressure offset setting values ​​of the transmission side and the operation side to obtain the control setpoint. Based on the actual gas supply pressure feedback value, the transmission-side electro-proportional valve and the operating-side electro-proportional valve are used to perform closed-loop pressure regulation on the transmission-side pressurization cylinder and the operating-side pressurization cylinder, respectively.

7. The control method according to claim 1, characterized by, Prior to the step of acquiring the real-time rotation data of the secondary arm, the method further includes: The secondary arm is controlled to move closer to the paper roll cylinder, and the rotation angle data of the secondary arm is monitored in real time. When the rotation angle data reaches a preset angle threshold, it is determined that the secondary arm has pressed the paper roll, and the step of obtaining the real-time rotation angle data of the secondary arm is triggered.

8. A constant line pressure control system for a horizontal cylinder paper reel, for implementing the control method according to any one of claims 1 to 7, characterized in that, include: An angle acquisition module is used to acquire the real-time rotation angle data of the secondary arm; The controller is communicatively connected to the angle acquisition module and is configured to calculate the real-time roll diameter data of the paper roll on the paper machine based on the real-time rotation angle data, according to a preset eccentric crank slider displacement geometric model. Based on the preset target constant linear pressure and the real-time roll diameter data, the target cylinder air supply pressure is calculated using the torque balance mechanical model of the secondary arm. A control command is generated based on the target cylinder's air supply pressure; The pressure execution module is communicatively connected to the controller. The pressure execution module includes an electro-proportional valve for adjusting the actual air supply pressure of the pressurizing cylinder according to the control command.

9. The control system of claim 8, wherein, The pressure execution module also includes a pressure sensor. The control terminal of the electro-proportional valve is electrically connected to the controller, and the output terminal of the electro-proportional valve is connected to the air circuit of the pressurizing cylinder. The pressure sensor is installed in the air intake circuit of the pressurizing cylinder and is connected to the controller for feedback, and is used to collect the actual air supply pressure feedback value of the pressurizing cylinder.

10. The control system of claim 9, wherein, The pressurizing cylinder includes a drive-side pressurizing cylinder and an operating-side pressurizing cylinder, and the electro-proportional valve includes a drive-side electro-proportional valve and an operating-side electro-proportional valve. The controller is further configured to: receive independent pressure offset setpoints from the drive side and the operating side; superimpose the target cylinder supply pressure with the independent pressure offset setpoints from the drive side and the operating side respectively to obtain a control setpoint; and, in conjunction with the actual supply pressure feedback value, independently send control commands to the drive-side electro-proportional valve and the operating-side electro-proportional valve to perform closed-loop pressure regulation on the drive-side pressurizing cylinder and the operating-side pressurizing cylinder respectively.

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