Hydraulic catheter push bending method and system based on force-position curve intelligent control

Abstract

This invention provides a hydraulic conduit bending method and system based on intelligent force-position curve control. The method includes placing a straight pipe into a bending die; connecting or abutting one end of the straight pipe with a main push cylinder, and connecting or abutting the other end of the straight pipe with a movable ball joint of a rear push cylinder; the main push cylinder pushes the straight pipe into the bending section of the bending die, while the rear push cylinder provides a reverse thrust; real-time monitoring of the position of the main push cylinder and the pressure of the rear push cylinder; calculating the ideal pressure setpoint of the rear push cylinder at the current displacement based on a preset optimal force-position curve; and outputting a control signal for the rear push cylinder's retraction speed based on the deviation between the actual rear push cylinder pressure and the setpoint. By using the optimal force-position curve and adjusting the rear push cylinder speed in real-time based on force-position feedback during the actual bending process, intelligent control of the conduit bending is achieved. Through the optimization and real-time tracking of the force-position curve, conduit damage caused by excessive or insufficient pressure during bending is effectively avoided, improving processing stability and yield.

Description

Technical Field

[0001] This invention belongs to the field of metal pipe forming technology, specifically, it relates to a hydraulic conduit bending method and system based on intelligent control of force-position curves. More particularly, it relates to a hydraulic bending device and its control method for bending straight pipes into curved pipes, which is especially suitable for processing small bending radius conduits in aerospace, automotive manufacturing, and other fields where high bending quality is required. Background Technology

[0002] Push bending is a common pipe bending process that uses molds and push devices to press straight pipes into bending cavities to cause plastic deformation.

[0003] In existing technologies, the push-bending process has several common problems: First, uneven friction during the push-bending process leads to thinning of the wall thickness or even cracking; second, it lacks real-time adjustment capabilities, making it difficult to cope with fluctuations in material properties or changes in process parameters; third, the control logic is mostly simple hardware-level feedback, lacking software-based intelligent control and self-learning capabilities, making it impossible to achieve continuous optimization and digital management of the process, and thus failing to meet the requirements in high-precision fields such as aerospace.

[0004] In the aerospace field, the requirements for pipe bending and forming are even higher. Existing bending machines suffer from insufficient bending capacity and cannot meet the requirements for large-scale pipe bending and forming, which has become a technical bottleneck in the processing of high-end conduits. Therefore, there is an urgent need for a new type of bending device and method that can monitor and intelligently adjust the bending process in real time and effectively reduce the probability of conduit damage. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a hydraulic conduit bending method and system based on intelligent control of force-position curves.

[0006] A hydraulic conduit bending method based on force-position curve intelligent control according to the present invention includes the following steps: Place the straight tube filled with rubber blocks into the vertical section of the bending die; Connect or abut the push rod of the main push cylinder to one end of the straight pipe, and connect or abut the movable ball joint of the rear push cylinder to the other end of the straight pipe; The main pusher cylinder pushes the straight pipe into the bending section of the bending die, and the rear pusher cylinder moves backward during the bending process and provides a reverse thrust. During the bending process, the position of the main push cylinder and the pressure of the rear push cylinder are monitored in real time; Based on the preset optimal force curve, the ideal pressure setting value of the rear cylinder under the current displacement is calculated in real time, and the control signal of the rear cylinder retraction speed is output based on the deviation between the actual pressure of the rear cylinder and the setting value. When the actual pressure of the rear cylinder is greater than the set value, increase the retraction speed of the rear cylinder; When the actual pressure of the rear cylinder is less than the set value, reduce the retraction speed of the rear cylinder.

[0007] In a preferred embodiment, the preset optimal force-position curve can be expressed as the displacement of the main thrust cylinder. and ideal rear cylinder pressure The mapping relationship is expressed as:

[0008] in, The effective displacement range of the main thrust cylinder. This is the initial displacement for pushing the bend. This represents the displacement at the end of the bend; this curve is obtained by fitting process test data and is usually represented by a polynomial model.

[0009] In the formula, , ... The coefficients are polynomials, obtained by fitting and optimizing the experimental data using the least squares method. Different models of catheters correspond to different sets of coefficients.

[0010] In a preferred embodiment, to eliminate sensor noise interference, the collected main pusher cylinder displacement is... and rear cylinder thrust Using Kalman filtering, the state equation and observation equation are as follows:

[0011] Wherein, the state vector express Displacement and thrust state at any given moment; Here is the displacement matrix. To control the input matrix, for The amount of control at any given moment; For the observation vector, For the observation matrix, , These are process noise and observation noise, respectively. The optimal estimate obtained after filtering iteration This serves as input data for subsequent control.

[0012] In a preferred embodiment, based on a preset optimal force-position curve, a fuzzy adaptive algorithm is used to calculate in real time the ideal pressure setpoint of the rear cylinder at the current displacement, and a control deviation rate is defined. and rate of change of deviation :

[0013] in, The actual pressure of the rear top cylinder after filtering. The ideal pressure setting value for the rear cylinder corresponding to the current displacement; The input to the fuzzy controller is the adjustment amount of the backward retraction speed of the rear cylinder. The following can be obtained through fuzzy rule reasoning:

[0014] The actual reverse speed of the rear cylinder has been updated as follows: .

[0015] In a preferred embodiment, self-learning and iterative optimization are also included: Based on historical databases, including force-position time-series data and molding quality test results, machine learning algorithms are used to iteratively update the optimal force-position curve with the goal of achieving the best molding quality. The slope and intercept of the force-position curve are continuously adjusted to better fit the characteristics of the pipe. An optimization objective function is constructed with the goal of achieving the best molding quality for the conduit.

[0016] In a preferred embodiment, process monitoring and fault diagnosis are also included: Abnormal operating conditions are identified using the deviation threshold method. An alarm is triggered when the relative deviation between the actual rear cylinder pressure and the ideal rear cylinder pressure exceeds a set threshold.

[0017] in, The system uses a preset relative deviation threshold; it also detects displacement deviation and hydraulic pressure deviation. When any parameter exceeds the threshold range, the system triggers a shutdown protection or warning and records the fault data.

[0018] According to the present invention, a hydraulic conduit bending system based on force-position curve intelligent control is provided, the system comprising: Frame and mold closing mechanism: The bending mold is mounted on the frame and has a cavity inside; Internal support: Consists of multiple rubber blocks filled inside the cavity of the straight tube to be bent; The main actuator includes a main push cylinder and a push rod driven by the main push cylinder, which is used to push the straight tube to move along the mold cavity to form the shape; The rear-mounted actuator includes a rear-mounted cylinder, the piston rod end of which is provided with a movable push head that abuts against the tail end of the straight pipe for providing a reverse thrust. The signal detection unit includes a position sensor for detecting the displacement of the main push cylinder, a force feedback sensor for detecting the thrust of the rear push cylinder, and an intelligent controller electrically connected to the position sensor and the force feedback sensor. The intelligent controller has a pre-stored optimal force-position curve corresponding to the model of the pipe being processed. The intelligent controller is configured to: during the bending process, based on the real-time displacement obtained by the position sensor, query the optimal force-position curve to obtain the ideal back jacking force setting value under the current displacement; compare the actual back jacking force detected by the force feedback sensor with the ideal back jacking force setting value, and adjust the backward speed of the back jacking cylinder accordingly, so that the actual back jacking force follows the ideal back jacking force setting value.

[0019] In a preferred embodiment, a hydraulic booster unit is also included: comprising a hydraulic booster and a hydraulic booster pipe communicating with the inner cavity of the straight pipe, for more accurate pressure control during the bending process.

[0020] In a preferred embodiment, it further includes: Data acquisition and preprocessing module: used to filter, remove outliers and synchronize time for the raw data acquired by position sensors and force feedback sensors; Force-position curve tracking control module: used to dynamically adjust the retraction speed of the rear cylinder based on the deviation between the actual rear force and the ideal rear force, using model predictive control or fuzzy adaptive algorithm. Self-learning and iterative optimization module: used to iteratively update the optimal force-position curve based on historical data and molding quality results; Process monitoring and fault diagnosis module: used to identify abnormal working conditions during the bending process and trigger protection mechanisms.

[0021] In a preferred embodiment, the optimal force-position curve is obtained by conducting process experiments using a specific type of conduit to optimize the relationship between the main push cylinder displacement and the rear push force, with the goal of achieving the best molding quality.

[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention establishes the optimal force-position curve for different types of guide tubes and adjusts the speed of the rear cylinder in real time based on the force-position feedback during the actual bending process, thereby achieving intelligent control of the guide tube bending.

[0023] 2. This invention effectively avoids conduit damage caused by excessive or insufficient pressure during the bending process by optimizing the force-position curve and tracking it in real time, thereby improving processing stability and yield.

[0024] 3. This invention is applicable to the bending of pipes with different diameters, wall thicknesses and materials, and in particular solves the technical bottleneck of high-precision conduit bending and forming in aerospace and other fields.

[0025] 4. Through the coordinated operation of multiple cylinders and internal support, the present invention achieves uniform pipe bending, high appearance quality, good dimensional accuracy, and strong consistency.

[0026] 5. This invention achieves full-process digitalization of data acquisition, control decision-making, self-learning optimization, and fault diagnosis through an intelligent control software system, thereby improving the replicability, stability, and traceability of the process.

[0027] 6. This invention continuously optimizes the force-position curve based on historical data through a self-learning module, enabling process parameters to adapt to the characteristics of different pipe materials and achieving intelligent improvement.

[0028] 7. This invention identifies abnormal operating conditions in advance through a process monitoring and fault diagnosis module, avoiding conduit damage and equipment failure, and improving the safety and reliability of bending. Attached Figure Description

[0029] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This invention mainly embodies the principle block diagram of an intelligent system; Figure 2 The flowchart illustrates the bending method of this invention. Detailed Implementation

[0030] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0031] Example 1 like Figure 1 and Figure 2 As shown, a hydraulic conduit bending method based on force-position curve intelligent control according to the present invention includes the following steps: A straight pipe filled with rubber blocks is placed into the vertical section of a bending die. The push rod of the main push cylinder is connected or abutted to one end of the straight pipe, and the movable ball joint of the rear push cylinder is connected or abutted to the other end of the straight pipe. The main push cylinder pushes the straight pipe into the bending section of the bending die, and the rear push cylinder retracts during the bending process and provides a reverse thrust. During the bending process, the position of the main push cylinder and the pressure of the rear push cylinder are monitored in real time. Based on the preset optimal force-position curve, the ideal pressure setpoint of the rear push cylinder at the current displacement is calculated in real time. Based on the deviation between the actual pressure of the rear push cylinder and the setpoint, a control signal for the retraction speed of the rear push cylinder is output. When the actual pressure of the rear push cylinder is greater than the setpoint, the retraction speed of the rear push cylinder is increased; when the actual pressure of the rear push cylinder is less than the setpoint, the retraction speed of the rear push cylinder is decreased.

[0032] This embodiment establishes the optimal force-position curves for different types of guide tubes and adjusts the speed of the rear push cylinder in real time based on the position of the main push cylinder and the force feedback of the rear push cylinder. This intelligent control of the real-time bending process significantly reduces the probability of guide tube damage and improves the quality and precision of bending.

[0033] Specifically, the preset optimal force-position curve can be expressed as the displacement of the main thrust cylinder. and ideal rear cylinder pressure The mapping relationship is expressed as:

[0034] in, The effective displacement range of the main thrust cylinder. This is the initial displacement for pushing the bend. This represents the displacement at the end of the bend; this curve is obtained by fitting process test data and is usually represented by a polynomial model.

[0035] In the formula, , ... The coefficients are polynomials, obtained by fitting and optimizing the experimental data using the least squares method. Different models of catheters correspond to different sets of coefficients.

[0036] Raw sensor data is acquired via an industrial bus, and Kalman filtering, outlier removal, and time synchronization are performed to eliminate noise and timing deviations, outputting a reliable force-position data set. To eliminate sensor noise interference, the acquired main cylinder displacement... and rear cylinder thrust Using Kalman filtering, the state equation and observation equation are as follows:

[0037] Wherein, the state vector express Displacement and thrust state at any given moment; Here is the displacement matrix. To control the input matrix, for The amount of control at any given moment; For the observation vector, For the observation matrix, , These are process noise and observation noise, respectively. The optimal estimate obtained after filtering iteration This serves as input data for subsequent control.

[0038] More specifically, based on the preset optimal force-position curve, a fuzzy adaptive algorithm is used to calculate the ideal pressure setpoint of the rear cylinder at the current displacement in real time, and define the control deviation rate. and rate of change of deviation :

[0039] in, The actual pressure of the rear top cylinder after filtering. The ideal pressure setting value for the rear cylinder corresponding to the current displacement; The input to the fuzzy controller is the adjustment amount of the backward retraction speed of the rear cylinder. The following can be obtained through fuzzy rule reasoning:

[0040] The actual reverse speed of the rear cylinder has been updated as follows: .

[0041] The control logic is: when When the actual thrust is greater than 0 (i.e., the actual thrust is greater than the ideal value), then >0, meaning increase backward speed; when When <0 (i.e., the actual thrust is less than the ideal value), then <0, meaning a reduction in backward speed. This allows the actual thrust to track the ideal curve.

[0042] In a preferred embodiment, it also includes self-learning and iterative optimization: based on a historical database containing force-position time-series data and molding quality detection results, a machine learning algorithm is used to iteratively update the optimal force-position curve with the goal of achieving the best molding quality. The slope and intercept of the force-position curve are continuously adjusted to make the subsequent process more consistent with the characteristics of the pipe. An optimization objective function is constructed with the goal of achieving the best molding quality of the conduit.

[0043] In a preferred embodiment, parameters such as force, displacement, and hydraulic pressure are detected in real time. Threshold judgments are used to identify abnormal operating conditions such as sensor malfunction, excessive thrust, and pipe deformation, triggering an alarm or automatic shutdown, and generating a fault log. The system also includes process monitoring and fault diagnosis: abnormal operating conditions are determined using a deviation threshold method. When the relative deviation between the actual rear cylinder pressure and the ideal rear cylinder pressure exceeds a set threshold, an alarm is triggered.

[0044] in, The system uses a preset relative deviation threshold; it also detects displacement deviation and hydraulic pressure deviation. When any parameter exceeds the threshold range, the system triggers a shutdown protection or warning and records the fault data.

[0045] According to the present invention, a hydraulic conduit bending system based on force-position curve intelligent control is provided, the system comprising: Frame and Mold Closing Mechanism: A bending die mounted on the frame, with an internal cavity. Internal Support: Composed of multiple rubber blocks filled into the cavity of the straight tube to be bent. Main Push Actuation Mechanism: Includes a main push cylinder and a push rod driven by the main push cylinder, used to push the straight tube along the mold cavity for forming. Rear Push Actuation Mechanism: Includes a rear push cylinder, the piston rod end of which has a movable push head that abuts against the tail end of the straight tube, used to provide a reverse push force. Signal Detection Unit: Includes a position sensor for detecting the displacement of the main push cylinder, a force feedback sensor for detecting the push force of the rear push cylinder, and an intelligent controller electrically connected to the position sensor and the force feedback sensor. The intelligent controller has pre-stored the optimal force-position curve corresponding to the type of pipe being processed. The controller is configured to: during the bending process, based on the real-time displacement obtained by the position sensor, query the optimal force-position curve to obtain the ideal back-pushing force setting value at the current displacement; compare the actual back-pushing force detected by the force feedback sensor with the ideal back-pushing force setting value, and adjust the retraction speed of the back-pushing cylinder accordingly, so that the actual back-pushing force follows the ideal back-pushing force setting value. It should be noted that the back-pushing force in this technical solution is the pressure of the back-pushing cylinder.

[0046] In a preferred embodiment, a hydraulic booster unit is also included: comprising a hydraulic booster and a hydraulic booster pipe communicating with the inner cavity of the straight pipe, for more accurate pressure control during the bending process.

[0047] It also includes: a data acquisition and preprocessing module: used for filtering, outlier removal, and time synchronization of raw data acquired by position sensors and force feedback sensors; a force-position curve tracking and control module: used to dynamically adjust the retraction speed of the rear push cylinder based on the deviation between the actual and ideal rear push force using model predictive control or fuzzy adaptive algorithms; a self-learning and iterative optimization module: used to iteratively update the optimal force-position curve based on historical data and forming quality results; and a process monitoring and fault diagnosis module: used to identify abnormal working conditions during the push-bending process and trigger protection mechanisms. In a preferred embodiment, the optimal force-position curve is obtained by optimizing the relationship data between the main push cylinder displacement and the rear push force through process experiments using a specific type of guide tube, with the goal of obtaining the best forming quality.

[0048] More specifically, the frame and mold-closing mechanism employ a four-column hydraulic press and mold-closing system, including an upper support plate, push rods, guide tubes, and bending tools. The bending mold has a guide sleeve inside, comprising a vertical section and a bending section. The straight pipe to be processed is installed within the vertical section of the guide sleeve, with both sections fitting snugly together. The four-column hydraulic press provides a stable clamping force, ensuring the mold remains tightly closed during the bending process.

[0049] The hydraulic actuator system includes a main pusher cylinder, a rear pusher cylinder, and a hydraulic booster. The main pusher cylinder is connected to the push rod and is responsible for pushing the straight pipe into the bending section; the rear pusher cylinder is pressed against the lower end of the straight pipe through a movable ball joint, providing a reverse pushing force during the bending process; the hydraulic booster is used to improve the accuracy of hydraulic control.

[0050] Example 2 Based on Embodiment 1, this invention provides a hydraulic conduit bending system based on intelligent control of force-position curves. The bending device of this invention includes a four-column hydraulic press, a bending die, a main push cylinder, a rear push cylinder, and an intelligent control system. The bending die is mounted on the lower table of the hydraulic press, and a guide sleeve is installed inside it. The straight pipe to be processed is installed within the vertical section of the guide sleeve, with the two fitting snugly together. Multiple rubber blocks are filled inside the straight pipe; these rubber blocks deform with the pipe during the bending process, providing internal support.

[0051] In this embodiment, the conduit to be processed is an aerospace-grade magnesium-aluminum alloy conduit with dimensions of [missing information]. For a diameter of 12×1mm and a bending radius of 2D, the optimal force-position curve is fitted using a cubic polynomial, and its form is as follows:

[0052] Among them, displacement The effective interval is The displacement unit is mm, and the thrust unit is N. This curve coefficient was obtained through process testing and can effectively balance the stress on the pipe during the bending process.

[0053] The tail end of the push rod is securely mounted on the main push cylinder, while the head end extends into the guide sleeve and abuts against the head end of the straight pipe via a sealing joint. The main push cylinder is connected to the push cylinder and is responsible for providing the bending power. The rear push cylinder abuts against the tail end of the straight pipe via a movable ball joint, which houses a force feedback sensor to monitor the pushing force during the bending process in real time.

[0054] refer to Figure 2 The force feedback sensor of the rear top cylinder is connected to the control system. The control system includes a signal acquisition module, a data processing module, and an output control module. The controller stores optimized force-position curves for different types of guide tubes. These curves are obtained through optimization using a large amount of experimental data and represent the optimal force-position relationship during the bending process.

[0055] When the thrust detected by the force feedback sensor deviates from the set value of the force-position curve at the current main push cylinder position by more than a preset range, the control system will adjust the retraction speed of the rear push cylinder accordingly; when the thrust is greater than the set upper limit, the retraction speed will be increased; when the thrust is less than the set lower limit, the retraction speed will be decreased.

[0056] In this embodiment, the input deviation of the fuzzy controller The domain of discourse is set as N, deviation rate The domain of discourse is set as N / s, output adjustment amount The domain of discourse is set as mm / s, through control logic, the backward speed of the rear cylinder can be adjusted in real time, the control period is 100ms, and the force-position tracking error can be controlled within ±3%.

[0057] Example 3 Based on Embodiment 1 or Embodiment 2, this invention provides a hydraulic conduit bending system based on force-position curve intelligent control, and provides a control interface diagram of the system.

[0058] It includes a hydraulic press control module, a main push cylinder control module, and a reverse push cylinder control module. The hydraulic press control module allows adjustment of "real-time displacement, real-time pressure, and real-time tonnage"; the main push cylinder and reverse push cylinder control modules allow adjustment of "real-time displacement and real-time pressure". In addition, the main interface displays information such as hydraulic station pressure, oil tank temperature, and part number. The lower part of the interface includes six main modules: "Main Interface," "Hydraulic Press Parameters," "Cylinder Parameters," "Programming Module," "Part Program Selection Module," and "Process Design Module."

[0059] In the hydraulic press parameter module, buttons for the hydraulic press to move downwards and backwards can be set, as well as parameters such as flow rate, pressure, and time. The clamping force and holding time of the hydraulic press can be controlled by pressure and time.

[0060] Under the cylinder parameter module, buttons can be set for the feed and retraction of the left push cylinder and the reverse push cylinder, as well as parameters such as flow rate, pressure, front limit, rear limit, and pressure limit. The hydraulic loading and flow rate of the left push cylinder are controlled by pressure and time. Specifically, under the reverse push cylinder parameters, two buttons can be set: constant pressure and variable pressure. Under constant pressure, the reverse push process maintains a constant pressure; under variable pressure, the reverse push pressure can be adjusted according to different displacements.

[0061] The programming module is used for variable pressure control of the thrust cylinder. Parameters such as project point, displacement, and pressure can be set. Project point is used to define the pressure point at different locations, displacement is used to set the specific displacement of the current point, and pressure is used to set the thrust pressure at the current point. Based on the displacement and pressure values ​​at different points obtained through programming, the change curve of the thrust force during the bending process can be obtained. By adjusting the parameters of displacement, pressure, and point, the speed of pressure loading (linear slope) can be controlled, thereby achieving adjustment between different pressures.

[0062] The part program selection module includes project number, part specification, and program number, totaling 9 specification parameters. These parameters are used to save data from the hydraulic press parameters, cylinder parameters, and programming module, and number them according to the corresponding pipe specifications. Subsequently, the corresponding bending parameters for different pipes are compiled in the corresponding programs for easy recall during actual operation.

[0063] The process design module includes mold parameter design, tube blank size design, rubber block design, lubrication condition design, and top thrust design. It designs corresponding mold structures, tube blank sizes, rubber blocks, lubrication conditions, and top thrust for different tube materials, thereby specifying the corresponding process parameters for the bending process and providing parameter support to the front end (hydraulic press parameters, cylinder parameters, and programming module).

[0064] Those skilled in the art will understand that, besides implementing the system and its various devices, modules, and units provided by this invention in the form of purely computer-readable program code, the same functions can be achieved entirely through logical programming of the method steps, making the system and its various devices, modules, and units of this invention function in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers. Therefore, the system and its various devices, modules, and units provided by this invention can be considered as a hardware component, and the devices, modules, and units included therein for implementing various functions can also be considered as structures within the hardware component; alternatively, the devices, modules, and units for implementing various functions can be considered as both software modules implementing the method and structures within the hardware component.

[0065] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application 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. Therefore, they should not be construed as limitations on this application.

[0066] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A hydraulic conduit bending method based on force-position curve intelligent control, characterized in that, Includes the following steps: Place the straight tube filled with rubber blocks into the vertical section of the bending die; Connect or abut the push rod of the main push cylinder to one end of the straight pipe, and connect or abut the movable ball joint of the rear push cylinder to the other end of the straight pipe; The main pusher cylinder pushes the straight pipe into the bending section of the bending die, and the rear pusher cylinder moves backward during the bending process and provides a reverse thrust. During the bending process, the position of the main push cylinder and the pressure of the rear push cylinder are monitored in real time; Based on the preset optimal force curve, the ideal pressure setting value of the rear cylinder under the current displacement is calculated in real time, and the control signal of the rear cylinder retraction speed is output based on the deviation between the actual pressure of the rear cylinder and the setting value. When the actual pressure of the rear cylinder is greater than the set value, increase the retraction speed of the rear cylinder; When the actual pressure of the rear cylinder is less than the set value, reduce the retraction speed of the rear cylinder.

2. The hydraulic conduit bending method based on force-position curve intelligent control according to claim 1, characterized in that, The preset optimal force-position curve can be expressed as the displacement of the main thrust cylinder. and ideal rear cylinder pressure The mapping relationship is expressed as: in, The effective displacement range of the main thrust cylinder. This is the initial displacement for pushing the bend. This represents the displacement at the end of the bend; this curve is obtained by fitting process test data and is usually represented by a polynomial model. In the formula, , ... The coefficients are polynomials, obtained by fitting and optimizing the experimental data using the least squares method. Different models of catheters correspond to different sets of coefficients.

3. The hydraulic conduit bending method based on force-position curve intelligent control according to claim 1, characterized in that, To eliminate sensor noise interference, the collected main pusher cylinder displacement was... and rear top cylinder thrust Using Kalman filtering, the state equation and observation equation are as follows: Wherein, the state vector express Displacement and thrust state at any given moment; Here is the displacement matrix. To control the input matrix, for The amount of control at any given moment; For the observation vector, For the observation matrix, , These are process noise and observation noise, respectively. The optimal estimate obtained after filtering iteration This serves as input data for subsequent control.

4. The hydraulic conduit bending method based on force-position curve intelligent control according to claim 1, characterized in that, Based on the preset optimal force-position curve, a fuzzy adaptive algorithm is used to calculate the ideal pressure setpoint of the rear cylinder at the current displacement in real time, and the control deviation rate is defined. and rate of change of deviation : in, The actual pressure of the rear cylinder after filtering. The ideal pressure setting value for the rear cylinder corresponding to the current displacement; The input to the fuzzy controller is the adjustment amount of the backward retraction speed of the rear cylinder. The following can be obtained through fuzzy rule reasoning: The actual reverse speed of the rear cylinder has been updated as follows: 。 5. The hydraulic conduit bending method based on force-position curve intelligent control according to claim 4, characterized in that, It also includes self-learning and iterative optimization: Based on historical databases, including force-position time-series data and molding quality test results, machine learning algorithms are used to iteratively update the optimal force-position curve with the goal of achieving the best molding quality. The slope and intercept of the force-position curve are continuously adjusted to better fit the characteristics of the pipe. An optimization objective function is constructed with the goal of achieving the best molding quality for the conduit.

6. The hydraulic conduit bending method based on force-position curve intelligent control according to claim 1, characterized in that, It also includes process monitoring and fault diagnosis: Abnormal operating conditions are identified using the deviation threshold method. An alarm is triggered when the relative deviation between the actual rear cylinder pressure and the ideal rear cylinder pressure exceeds a set threshold. in, The system uses a preset relative deviation threshold; it also detects displacement deviation and hydraulic pressure deviation. When any parameter exceeds the threshold range, the system triggers a shutdown protection or warning and records the fault data.

7. A hydraulic conduit bending system based on force-position curve intelligent control, characterized in that, The system for performing the hydraulic conduit bending method based on force-position curve intelligent control as described in any one of claims 1 to 6 includes: Frame and mold closing mechanism: The bending mold is mounted on the frame and has a cavity inside; Internal support: Consists of multiple rubber blocks filled inside the cavity of the straight tube to be bent; The main actuator includes a main push cylinder and a push rod driven by the main push cylinder, which is used to push the straight tube to move along the mold cavity to form the shape; The rear-mounted actuator includes a rear-mounted cylinder, the piston rod end of which is provided with a movable push head that abuts against the tail end of the straight pipe for providing a reverse thrust. The signal detection unit includes a position sensor for detecting the displacement of the main push cylinder, a force feedback sensor for detecting the thrust of the rear push cylinder, and an intelligent controller electrically connected to the position sensor and the force feedback sensor. The intelligent controller has a pre-stored optimal force-position curve corresponding to the model of the pipe being processed. The intelligent controller is configured to: during the bending process, based on the real-time displacement obtained by the position sensor, query the optimal force-position curve to obtain the ideal back jacking force setting value under the current displacement; compare the actual back jacking force detected by the force feedback sensor with the ideal back jacking force setting value, and adjust the backward speed of the back jacking cylinder accordingly, so that the actual back jacking force follows the ideal back jacking force setting value.

8. The hydraulic conduit bending system based on force-position curve intelligent control according to claim 7, characterized in that, It also includes a hydraulic booster unit: including a hydraulic booster and a hydraulic booster pipe that communicates with the inner cavity of the straight pipe, for more accurate pressure control during the bending process.

9. The hydraulic conduit bending system based on force-position curve intelligent control according to claim 7, characterized in that, Also includes: Data acquisition and preprocessing module: used to filter, remove outliers and synchronize time for the raw data acquired by position sensors and force feedback sensors; Force-position curve tracking control module: used to dynamically adjust the retraction speed of the rear cylinder based on the deviation between the actual rear force and the ideal rear force, using model predictive control or fuzzy adaptive algorithm. Self-learning and iterative optimization module: used to iteratively update the optimal force-position curve based on historical data and molding quality results; Process monitoring and fault diagnosis module: used to identify abnormal working conditions during the bending process and trigger protection mechanisms.

10. The hydraulic conduit bending system based on force-position curve intelligent control according to claim 7, characterized in that, The optimal force-position curve is obtained by conducting process experiments on a specific type of conduit to achieve the best molding quality, and by optimizing the relationship between the displacement of the main push cylinder and the rear push force.

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