Adaptive control method and system for numerical control space pipe bender

Abstract

The application discloses a numerical control space pipe bending machine adaptive control method and system, relates to the technical field of numerical control equipment automatic control, and comprises the following steps: acquiring pipe material parameters, inquiring a process database to determine a bending thrust, a speed and a springback compensation coefficient, driving a bending forming mechanism to execute three-dimensional bending, collecting bending force feedback and stopping protection when exceeding the limit; preloading a three-dimensional center line model of a pipe, real-time discrete solving a dynamic lowest point three-dimensional coordinate of a forming pipe section, independently outputting a position instruction of a three-axis servo follow-up support unit, tracking a lowest point of the pipe and only supporting vertical dead weight of the pipe; outputting a descending avoidance instruction when a self-rotation process is detected, outputting a reset following instruction after posture stabilization; and synchronously feeding, self-rotating, bending and supporting following instructions through a real-time bus, and cooperatively completing three-dimensional continuous bending. Multi-axis adaptive linkage is realized, and forming precision and equipment stability are improved.

Description

Technical Field

[0001] This invention relates to the field of CNC equipment automation control technology, specifically to an adaptive control method and system for a CNC spatial pipe bending machine. Background Technology

[0002] Numerous spatially curved pipe fittings exist in boiler heating surface tube bundles, thermal pipelines, and three-dimensional spatial piping of engineering machinery, requiring continuous bending at different planes and angles on the pipe material. Existing technologies mostly rely on conventional pipe bending equipment capable of bending only in a single plane. Complex spatial tube bundles can only be assembled by segmented bending followed by on-site welding, resulting in numerous weld joints and potential residual stress and pipe deformation. The few devices capable of spatial bending typically have fixed bending outputs that cannot be automatically matched to pipe parameters, and lack online compensation for material springback after bending, leading to unstable angular accuracy.

[0003] The existing technologies mentioned above also have the following problems: First, during the continuous bending process of long-length pipes, the lowest point of the formed pipe segment constantly drifts dynamically. There is no effective means to suppress the sagging deformation caused by the pipe's own weight. Conventional fixed rollers or single-axis traveling supports cannot follow the lowest point of arbitrary spatial posture drift. At the same time, the bending moment of the pipe's own weight is borne by the rotating chuck and slewing bearing for a long time, causing wear and precision drift of core components. Second, when the pipe rotates to switch bending planes, if the support unit continues to follow and support, it will cause squeezing interference with the rotation action. If the support unit is removed, the formed segment loses support. The existing solutions lack a time-series coordination mechanism between the support action and the rotation action in the process. Third, there is no strict synchronization mechanism for axial feeding, pipe rotation, bending and forming, and support following multi-axis actions. The cumulative deviation of multi-axis actions leads to a decrease in the forming accuracy of the spatial pipe segment. In addition, there is no dual-path overload protection for bending force and servo torque, resulting in poor equipment operation stability. Therefore, existing technologies lack an adaptive control scheme for CNC spatial pipe bending machines that can integrate adaptive matching of pipe parameters, dynamic follow-up support of the lowest point of the formed pipe section, time-sequence avoidance of rotation process, and synchronous linkage of multi-axis real-time bus into a unified control framework. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the purpose of this invention is to provide an adaptive control method and system for a CNC spatial pipe bending machine, enabling multi-axis adaptive linkage and improving forming accuracy and equipment stability.

[0005] To achieve the above objectives, the embodiments of this invention provide the following technical solutions:

[0006] This application provides an adaptive control method for a CNC spatial pipe bending machine, applied to a CNC spatial pipe bending machine including a feeding rotation mechanism, a bending forming mechanism, and a three-axis servo follow-up support unit. The method includes: a parameter acquisition step: acquiring pipe parameters including pipe diameter, wall thickness, material, and bending radius; a bending adaptive control step: querying a pipe process database based on the pipe parameters to determine the bending thrust command, bending speed command, and springback compensation coefficient, driving the bending forming mechanism to perform three-dimensional bending, and collecting bending force feedback signals. When the bending force exceeds the pipe's limit protection threshold, a stop protection signal is output; the follow-up... Support control steps: Preload the three-dimensional centerline model of the pipe fitting, and solve the three-dimensional coordinates of the dynamic lowest point of the formed pipe section in real time. Output position commands independently to each three-axis servo follow-up support unit, track the lowest point of the pipe in the jurisdiction and only bear the vertical self-weight of the pipe; when the pipe enters the rotation process, output the descent avoidance command, and output the reset follow command after the rotation is completed and the posture is stable; Multi-axis linkage control steps: output the feeding, rotation, bending and support follow commands synchronously through the real-time bus, so that each mechanism can work together to complete the three-dimensional continuous bending; the self-weight of the pipe is borne by the follow-up support unit, and the chuck only transmits the clamping force, feeding force and torsional torque.

[0007] Furthermore, the parameter acquisition step includes dual-mode parameter input: in response to a manual input instruction, receiving pipe parameters input via a human-computer interaction unit; or, in response to a drawing import instruction, reading a 3D CAD pipe fitting drawing file, the drawing file containing geometric data of the pipe fitting centerline and a pipe fitting details table, parsing the geometric data of the pipe fitting centerline and extracting the pipe diameter, wall thickness, bending radius, and bending angle and bending plane angle of each bend to generate the pipe parameters; and cross-checking the parsing results with the pipe fitting details table in the drawing, outputting a parameter alarm when the check is inconsistent.

[0008] Furthermore, the step of determining the bending thrust command by querying the pipe process database based on pipe parameters includes: calculating the theoretical bending thrust based on pipe diameter, wall thickness, material, and bending radius. ;in For theoretical bending thrust, This is a correction factor related to the material. The yield strength of the pipe material. For pipe wall thickness, The outer diameter of the pipe. The bending radius is given. Based on the theoretical bending thrust, the bending speed ratio coefficient and the springback compensation coefficient are determined by querying the pipe process database according to the material type: a lower bending thrust is used in combination with a higher bending speed for carbon steel, and a higher bending thrust is used in combination with a lower bending speed for alloy heat-resistant steel. The bending thrust command is generated by limiting the theoretical bending thrust according to the rated output range of the servo electric bending actuator.

[0009] Further, the real-time discrete solution of the three-dimensional coordinates of the dynamic lowest point of the formed pipe segment includes: discretizing the three-dimensional centerline model of the pipe into several model points at a preset step size; performing coordinate transformation on each model point according to the bending angle and feeding length of the completed bending process to obtain the real-time pose of the formed pipe segment in the equipment coordinate system; for each support unit, in the subset of model points corresponding to its jurisdiction, taking the model point with the smallest vertical coordinate as the dynamic lowest point tracked by the support unit, and generating three position commands for the support unit: X-axis feeding follow-up, Y-axis lateral offset compensation, and Z-axis vertical height adjustment; wherein the real-time pose of the formed pipe segment in the equipment coordinate system is updated by the following formula: ;in The coordinates of the point in the local coordinate system of the pipe fitting are given. These are the coordinates in the device coordinate system after the transformation. Let be the rotation matrix that rotates the pipe around the Z-axis of the equipment by the rotation angle β. Let be the rotation matrix for the bending angle α around the Y-axis of the equipment. Let L be the translation vector along the axial feeding length L.

[0010] Furthermore, the position command output to the three-axis servo-driven support unit adopts force / position hybrid control: the Z-axis vertical height adjustment loop works in position control mode, with the vertical coordinate of the dynamic lowest point as the target position and a preset support gap superimposed; the universal floating V-shaped roller of the support unit is equipped with a vertical force sensor. When the support force detected by the vertical force sensor is greater than the target support force corresponding to the unit length self-weight of the pipe, it is determined to be a hard top interference and the Z-axis is lowered; when the support force is less than the target support force, it is determined to be an empty support and the Z-axis is raised, so that the support force is maintained near the target support force. The support unit only bears the vertical self-weight of the pipe and does not apply lateral constraint load.

[0011] Furthermore, the step of detecting the pipe entering the rotation process and outputting a descent avoidance command includes: parsing the current bending process sequence; at a preset lead time before the feeding rotation mechanism executes the pipe rotation command; outputting a Z-axis descent command to all support units, with the descent range being a preset safety avoidance gap; blocking the Z-axis position command output of each support unit during the execution of the rotation command; and after detecting the pipe rotation angle reaching the target position and the pipe attitude angular velocity being lower than the stable threshold for a preset duration, releasing the block and outputting a reset follow command recalculated according to the dynamic lowest point.

[0012] Furthermore, it also includes a support unit scheduling step based on the total forming length of the pipe fitting: the total forming length of the pipe fitting is calculated according to the three-dimensional centerline model of the pipe fitting. When the total forming length does not exceed the pipe length boundary threshold, it is determined to be a short pipe condition. Only the number of support units required to cover the forming pipe segment is activated and they operate according to the first set of speed parameters and the first clearance gap. When the total forming length exceeds the pipe length boundary threshold, it is determined to be a long pipe condition. All support units are activated to work together and operate according to the second set of speed parameters lower than the first set of speed parameters and the second clearance gap greater than the first clearance gap. Real-time monitoring of the deflection of the forming pipe segment is also enabled. When the monitored deflection exceeds the deflection warning threshold, a deflection over-limit warning signal is output.

[0013] Furthermore, the springback compensation coefficient is corrected online in the following manner: a bending angle detection unit is installed at the bending forming mechanism to detect the actual bending angle of the pipe after each bending and calculate the springback deviation angle of that bending: ,in The springback deviation angle, This is the bending angle command value. The actual bending angle is measured by the bending angle detection unit; the bending angle command for the next bend is executed according to the corrected command angle. ;in This is the command for the corrected bending angle of the next bend. The target bending angle for the next bend; and the springback deviation angle. Iteratively correct the springback compensation coefficient corresponding to the pipe parameters in the pipe process database.

[0014] Furthermore, in the multi-axis linkage control step, the infinite-position servo rotation mechanism of the feeding rotation mechanism is connected to the power supply and control bus via a conductive slip ring. The conductive slip ring continuously transmits power and encoder feedback signals during the 360° continuous rotation of the chuck. The real-time bus is an industrial real-time fieldbus, and axial feeding commands, pipe rotation commands, bending commands, and support following commands are all issued with the same synchronous clock flag. In addition, the multi-axis linkage controller performs overload monitoring on the servo motor torque of the feeding rotation mechanism and the bending force of the bending forming mechanism. When the torque or bending force exceeds its respective protection threshold, the corresponding servo enable is cut off and an overload alarm is output.

[0015] Accordingly, this application also provides an adaptive control system for a CNC spatial pipe bending machine, including a parameter management unit, a bending servo control unit, a follow-up support control unit, a multi-axis linkage controller, a data storage unit, and a human-machine interaction unit; the parameter management unit is connected to the human-machine interaction unit and the data storage unit, and is used to receive pipe parameters manually entered or obtained from the analysis of three-dimensional CAD drawings and write them into the data storage unit; the bending servo control unit is connected to the multi-axis linkage controller and the data storage unit, and is used to query the pipe process database according to the pipe parameters to generate bending thrust commands, bending speed commands, and springback compensation coefficients, drive the servo electric push bending actuator and hydraulic clamping assembly of the bending forming mechanism, and receive bending force feedback signals to execute limit threshold shutdown protection; the follow-up support control unit is connected to the multi-axis linkage controller, and its output terminal is connected to the X-axis, Y-axis, and Z-axis servo drivers of multiple sets of three-axis servo follow-up support units, respectively, for pre-... The system uses a 3D centerline model of the pipe fitting and real-time discrete solution to calculate the 3D coordinates of the dynamic lowest point of the formed pipe segment. It independently outputs position commands to each support unit and outputs descent and resetting commands during the pipe rotation process. The multi-axis linkage controller is connected via an industrial real-time fieldbus to the servo-driven trolley driver of the feeding and rotating mechanism, the infinite-position servo rotating mechanism, the bending servo control unit, and the follow-up support control unit. It issues axial feeding commands, pipe rotation commands, bending commands, and support follow-up commands at the same synchronous clock. The infinite-position servo rotating mechanism is connected to the power supply and control bus via a conductive slip ring. The data storage unit is connected to the parameter management unit, the bending servo control unit, and the follow-up support control unit, respectively, to store the pipe process database, the 3D centerline model of the pipe fitting, and operating status data. The human-machine interface unit is connected to the parameter management unit and the multi-axis linkage controller for parameter input, status display, and alarm output.

[0016] The beneficial effects of this invention are as follows: By integrating pipe parameter query and matching, bending force feedback protection, forming pipe section minimum point tracking, self-rotation process avoidance, and multi-axis bus synchronous linkage into a unified control process, the invention achieves the technical effect of automated collaborative and adaptive control of the entire spatial pipe bending process; through the force load separation control configuration, it achieves the technical effect of protecting the rotating chuck and slewing bearing from wear caused by their own weight bending moment and ensuring the long-term stable accuracy of the equipment; through online correction of the springback compensation coefficient, it achieves bending angle convergence and high-precision control; through intelligent switching of long and short pipe working conditions and deflection monitoring, it achieves compatibility and protection for pipes of different specifications, significantly improving the intelligence level and processing reliability of the equipment. Attached Figure Description

[0017] Figure 1A flowchart illustrating an adaptive control method for a CNC spatial pipe bending machine provided in an embodiment of this application;

[0018] Figure 2 This is a schematic diagram of the structure of an adaptive control system for a CNC spatial pipe bending machine provided in an embodiment of this application. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the scope of the present invention.

[0020] In this invention, the terms "system" and "network" are used interchangeably. "Multiple" refers to two or more; therefore, in this invention, "multiple" can also be understood as "at least two." "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, it should be understood that in the description of this invention, terms such as "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or order.

[0021] Example 1:

[0022] like Figure 1As shown, this application provides an adaptive control method for a CNC spatial tube bending machine, applied to a CNC spatial tube bending machine including a feeding and rotating mechanism, a bending and forming mechanism, and a three-axis servo follow-up support unit. The CNC spatial tube bending machine's hardware configuration includes: a feeding and storage module composed of multiple sets of fixed horizontal rollers, providing rigid support for the straight tube to be processed throughout the process; and a servo feeding and rotating module including a servo moving carriage, a high-strength clamping chuck mounted on the carriage, an infinite-position servo rotating mechanism driving the chuck to rotate infinitely, and a conductive slip ring assembly, used to complete... The system includes: axial feeding, pipe clamping, and pipe rotation for bending plane switching; a bending forming main module, comprising a quick-change bending die, clamping die, pusher die, servo-electric push-bending actuator, and hydraulic clamping assembly, for completing bending forming; a three-axis follow-up anti-sagging support module, composed of multiple independent three-axis servo follow-up support units, each with three servo motion axes: X longitudinal feeding follow, Y lateral offset compensation, and Z vertical height adjustment, with universal floating V-shaped rollers at the bearing end; and a CNC electronic adaptive system, including a parameter management unit and bending servo... The system includes a control unit, a follow-up support control unit, a multi-axis linkage controller, a data storage unit, and a human-machine interaction unit, comprising: a parameter acquisition step: acquiring pipe parameters including pipe diameter, wall thickness, material, and bending radius; a bending adaptive control step: querying the pipe process database based on the pipe parameters to determine the bending thrust command, bending speed command, and springback compensation coefficient, driving the bending forming mechanism to perform three-dimensional bending, and collecting bending force feedback signals; outputting a shutdown protection signal when the bending force exceeds the pipe's limit protection threshold; and a follow-up support control step: preloading the pipe fitting in three dimensions. The centerline model is used to discretely solve the three-dimensional coordinates of the dynamic lowest point of the formed pipe segment in real time. It independently outputs position commands to each three-axis servo follow-up support unit, tracks the lowest point of the pipe in the jurisdiction, and only bears the vertical weight of the pipe. When the pipe enters the rotation process, it outputs a descent avoidance command. After the rotation is completed and the posture is stable, it outputs a reset follow command. Multi-axis linkage control steps: feeding, rotation, bending and support follow commands are output synchronously via real-time bus, so that each mechanism can work together to complete three-dimensional continuous bending. The weight of the pipe is borne by the follow-up support unit, and the chuck only transmits clamping force, feeding force and torsional torque.

[0023] In one possible embodiment, firstly, after the system is powered on and initialized, the CNC adaptive system performs a parameter acquisition step: receiving the pipe parameters of the pipe to be processed through the human-machine interface unit. The pipe parameters include pipe diameter, wall thickness, material, and bending radius. The parameters can be manually entered or automatically obtained from 3D CAD pipe drawings. Then, the bending adaptive control step is executed: the bending servo control unit queries the pipe process database in the data storage unit using the pipe parameters as an index to determine the bending thrust command, bending speed command, and springback compensation coefficient corresponding to the pipe. The results are then output to the servo electric push bending actuator of the bending forming host module to drive the bending die to complete the 3D bending. During the bending process, the force detection element installed on the bending forming host module collects the bending force feedback signal in real time. The bending servo control unit compares the bending force feedback signal with the limit protection threshold corresponding to the pipe parameters. When the bending force exceeds the limit protection threshold, a stop protection signal is immediately output to cut off the bending power output and prevent the pipe from being crushed or the equipment from being overloaded. Next, the follow-up support control step is executed: the follow-up support control unit preloads the three-dimensional centerline model of the pipe to be processed, and discretely solves the three-dimensional coordinates of the dynamic lowest point of the formed pipe section in real time during the bending process, and outputs position commands independently to each three-axis servo follow-up support unit, so that each support unit tracks the lowest point of the pipe in its own jurisdiction. The omnidirectional floating V-shaped roller only bears the vertical self-weight of the pipe and does not apply lateral constraint load. When the system detects that the pipe is about to enter the self-rotation process (i.e., the pipe is rotated around its own axis by the chuck to switch the bending plane) according to the process sequence, it outputs a descending avoidance command to each support unit, so that the rollers are separated from the surface of the pipe to form a safe gap. After the self-rotation is completed and the posture of the pipe is stable, a reset follow command is output to make the rollers re-fit and support. Finally, the multi-axis linkage control step is executed: the multi-axis linkage controller synchronously outputs feeding commands, rotation commands, bending commands, and support following commands to the servo feeding rotation module, bending forming host module, and three-axis follow-up support module via real-time bus. All four types of commands carry the same synchronous clock mark, so that axial feeding, pipe rotation, bending forming, and support following are strictly coordinated in time to complete continuous bending in three-dimensional space. In terms of the mechanical configuration of the whole machine, the force load separation method is adopted. The bending moment of the pipe's own weight is entirely borne by the three-axis servo follow-up support unit. The clamping chuck only transmits clamping force, axial feeding force, and torsional torque, and does not bear the vertical overturning bending moment.

[0024] By integrating pipe parameter query and matching, bending force feedback protection, forming pipe section minimum point tracking, self-rotation process avoidance and multi-axis bus synchronous linkage into a unified control process, the technical effect of automated collaboration and adaptive control of the entire spatial pipe bending process is achieved; through the force load separation control configuration, the technical effect of protecting the rotating chuck and slewing bearing from self-weight bending moment wear is achieved, and the long-term operation accuracy and stability of the equipment are ensured.

[0025] In embodiments of this application, the parameter acquisition step includes dual-mode parameter input: in response to a manual input instruction, receiving pipe parameters input via a human-computer interaction unit; or, in response to a drawing import instruction, reading a three-dimensional CAD pipe fitting drawing file, the drawing file containing geometric data of the pipe fitting centerline and a pipe fitting details table, parsing the geometric data of the pipe fitting centerline and extracting the pipe diameter, wall thickness, bending radius, and bending angle and bending plane angle of each bend to generate the pipe parameters; and cross-checking the parsing results with the pipe fitting details table in the drawing, outputting a parameter alarm when the check is inconsistent.

[0026] In one possible embodiment, the system first provides two parameter input modes: In manual input mode, the operator inputs the pipe diameter, wall thickness, material, bending radius, and bending angles and bending plane angles of each bend of the pipe to be processed through a human-computer interaction unit (such as a touch screen operating terminal). The parameter management unit receives the input and writes it into the data storage unit. In drawing import mode, the operator imports the 3D CAD drawing file of the pipe to be processed, and the parameter management unit calls the drawing parsing program to read the file. Then, the drawing parsing program traverses the pipe model in the 3D CAD drawing, identifies the geometric element of the pipe centerline, which refers to the spatial broken line or spline curve that runs through the axis of each segment of the pipe. The parsing program extracts the geometric data of the centerline, including the length of each pipe segment, the bending angle at each bend, and the spatial angle between adjacent bending planes (i.e., bending plane angles), and extracts the pipe diameter, wall thickness, and bending radius from the drawing annotations or model attributes to generate structured pipe parameters. The parameter management unit then cross-checks the parsed parameters with the pipe fittings list attached to the drawings (i.e., the material list in the drawing title block area, which records information such as pipe specifications, materials, and quantities): comparing whether the pipe diameter, wall thickness, material, and bending radius are consistent. Finally, if the check is consistent, the parameter management unit writes the pipe parameters to the data storage unit and sets the parameter ready flag, allowing subsequent bending processes to start; if the check is inconsistent, the human-machine interaction unit outputs a parameter alarm, which includes displaying the specific inconsistent parameter items and their respective values ​​in the drawings and the list, prompting the operator to review, and prohibiting automatic processing from starting until the alarm is cleared.

[0027] By providing dual-mode parameter input—manual input and one-click parsing of 3D CAD drawings—and cross-validating the parameters with the pipe fittings list after drawing parsing, the system achieves convenient acquisition of pipe parameters and proactive interception of parameter errors, preventing batch scrapping caused by erroneous parameters entering the bending control system.

[0028] In the embodiments of this application, determining the bending thrust command by querying the pipe process database based on pipe parameters includes: calculating the theoretical bending thrust based on pipe diameter, wall thickness, material, and bending radius. ;in For theoretical bending thrust, This is a correction factor related to the material. The yield strength of the pipe material. For pipe wall thickness, The outer diameter of the pipe. The bending radius is given. Based on the theoretical bending thrust, the bending speed ratio coefficient and the springback compensation coefficient are determined by querying the pipe process database according to the material type: a lower bending thrust is used in combination with a higher bending speed for carbon steel, and a higher bending thrust is used in combination with a lower bending speed for alloy heat-resistant steel. The bending thrust command is generated by limiting the theoretical bending thrust according to the rated output range of the servo electric bending actuator.

[0029] In one possible embodiment, firstly, the bending servo control unit establishes a bending mechanics model with four dimensions as input: pipe diameter, wall thickness, material, and bending radius. The essence of pipe bending is to induce plastic deformation in the bent section of the pipe. According to the theory of plastic bending, the bending moment required to induce plastic yielding in the pipe cross-section is determined. Yield strength of pipe material And it is directly proportional to the section modulus W of the pipe cross section, that is For a circular tube cross-section, the section modulus of bending... By pipe diameter With wall thickness It is determined that the greater the wall thickness and the larger the pipe diameter, the stronger the bending resistance of the cross-section. The dimensional relationship is as follows: and The same magnitude; while the bending thrust applied by the bending actuator during bending. A moment is generated about the center of the bend, with the lever arm being the radius of the bend. At the order of magnitude, and Proportional. Combining the above relationships, and introducing a correction factor related to the material. ( This is used for comprehensive correction of factors such as material hardening characteristics, cross-sectional shape deviation, and die friction (its values ​​are provided by the pipe process database according to material category), resulting in the theoretical bending thrust calculation formula: ,in For theoretical bending thrust, This is a correction factor related to the material. The yield strength of the pipe material. For pipe wall thickness, The outer diameter of the pipe. Let be the bending radius. From this formula, we can know that the wall thickness... The larger the yield strength of the material The higher the bending radius The smaller the value, the lower the theoretical bending thrust required. The larger the value. Then, the bending servo control unit uses the theoretical bending thrust. Based on this, the bending speed ratio and springback compensation coefficient are determined by querying the pipe process database according to material type, and a differentiated processing logic is implemented: For carbon steel pipes, the material has low deformation resistance, so the database corresponds to a lower bending thrust level and a higher bending speed to improve forming efficiency; for alloy heat-resistant steel pipes, the material has high strength and high deformation resistance, so the database corresponds to a higher bending thrust level and a lower bending speed to match the deformation characteristics of the alloy material and avoid defects such as pipe wall cracking, internal wrinkles, and cross-sectional ellipticity deviation. Then, the theoretical bending thrust is... The bending actuator is limited according to its rated output range. This limitation means that when the calculated thrust is lower than the actuator's minimum stable output, the output is raised to the minimum; when the calculated thrust is higher than the actuator's rated maximum output, it is limited to the rated maximum output with a warning. After limitation, the final bending thrust command is generated. Simultaneously, the bending speed command and springback compensation coefficient are also issued. Finally, during the bending process, the force detection element collects the bending force feedback signal in real time. The bending servo control unit compares this signal with the limit protection threshold corresponding to the pipe material parameters in the database. If the threshold is exceeded, a shutdown protection signal is immediately output. The limit protection threshold is the upper limit of the bending force at which the corresponding pipe material is at risk of crushing or wrinkling, and it is preset in the database according to pipe diameter, wall thickness, and material.

[0030] By establishing a four-dimensional bending mechanics model for pipe diameter, wall thickness, material, and bending radius, and deriving the theoretical bending thrust formula, the technical effect of stepless adaptive matching of bending output with pipe parameters was achieved. Through differentiated thrust and speed matching between carbon steel and alloy heat-resistant steel, as well as bending force limit threshold shutdown protection, the technical effect of anti-wrinkle thin-walled pipes, powerful forming of thick-walled alloy pipes, and equipment overload protection was achieved.

[0031] In the embodiments of this application, the real-time discrete solution of the three-dimensional coordinates of the dynamic lowest point of the formed pipe segment includes: discretizing the three-dimensional centerline model of the pipe into several model points at a preset step size; performing coordinate transformation on each model point according to the bending angle and feeding length of the completed bending process to obtain the real-time pose of the formed pipe segment in the equipment coordinate system; for each support unit, in the subset of model points corresponding to its jurisdiction, taking the model point with the smallest vertical coordinate as the dynamic lowest point tracked by the support unit, and generating three position commands for the support unit: X-axis feeding follow, Y-axis lateral offset compensation, and Z-axis vertical height adjustment; wherein the real-time pose of the formed pipe segment in the equipment coordinate system is updated by the following formula: ;in The coordinates of the point in the local coordinate system of the pipe fitting are given. These are the coordinates in the device coordinate system after the transformation. Let be the rotation matrix that rotates the pipe around the Z-axis of the equipment by the rotation angle β. Let be the rotation matrix for the bending angle α around the Y-axis of the equipment. Let L be the translation vector along the axial feeding length L.

[0032] In one possible embodiment, the follow-up support control unit first loads the three-dimensional centerline model of the pipe to be processed from the data storage unit, and discretizes it into several model points along the centerline at a preset step size. The model points refer to discrete points obtained by sampling along the centerline at fixed arc length intervals. Each model point has coordinates in the local coordinate system of the pipe (a coordinate system established with the initial axis of the pipe as the axis and as the pipe is fed in). Where x is the axial coordinate and y and z are the in-cross-section coordinates. Then, during the bending process, after each bending operation or advance of one step, the follow-up support control unit adjusts the current bending angle based on the completed bending angle. Pipe rotation angle and cumulative feeding length A coordinate transformation is performed on all shape points, transforming them from the local coordinate system of the pipe fitting to the equipment coordinate system (a fixed spatial coordinate system with the bending machine as the origin). This coordinate transformation consists of a transformation chain of three basic motions: axial feeding length... Corresponding translation along the equipment axis Pipe rotation angle Corresponding to rotation around the Z-axis (vertical) of the device Bending angle Corresponding to rotation about the device's Y-axis (lateral direction) Following the kinematic sequence of feeding—rotation—bending, the equipment coordinates after the shape point transformation are: ,in The coordinates of the point in the local coordinate system of the pipe fitting are given. These are the coordinates in the device coordinate system after the transformation. Let be the rotation matrix that rotates the pipe around the Z-axis of the equipment by the rotation angle β. Let be the rotation matrix for the bending angle α around the Y-axis of the equipment. Let T(L) be the translation vector along the axial feeding length L. The two rotation matrices are constructed in the form of standard spatial rotation matrices, with matrix elements consisting of the sine and cosine functions of the rotation angle. The axial component of the translation vector T(L) is equal to the feeding length L. For the case of continuous forming of multiple bends, the above transformation is cascaded sequentially according to the bend sequence, i.e., each bend introduces its own rotation amount and accumulates the translation amount. Then, for each three-axis servo-driven support unit, the vertical coordinates are taken from the subset of shape value points corresponding to its jurisdiction (i.e., the set of shape value points whose spatial positions fall within the area handled by that unit). The minimum shape value point serves as the dynamic lowest point that the support unit needs to track. This lowest point is continuously updated as the bending progresses, reflecting the lowest support position of the formed three-dimensional pipe segment under gravity. Finally, the follow-up support control unit generates three position commands for the support unit based on the coordinates of the dynamic lowest point: an X-axis feeding follow command (moving the unit longitudinally to the axial position of the lowest point), a Y-axis lateral offset compensation command (moving the unit laterally to the lateral position of the lowest point), and a Z-axis vertical height adjustment command (raising or lowering the roller to the support height). These three commands are sent to the corresponding servo drivers via a real-time bus.

[0033] By discretizing the centerline of the pipe fitting into shape value points and transforming the coordinates in real time according to the kinematic chains of feeding, rotation, and bending, the technical effect of accurately solving the dynamic minimum point of the formed spatial pipe segment unit by unit was achieved; by independently issuing X, Y, and Z position commands to each support unit, the technical effect of multi-unit jurisdiction without empty support and adapting to arbitrary drift of the pipe's spatial posture was achieved.

[0034] In the embodiments of this application, the position command output to the three-axis servo follow-up support unit adopts force / position hybrid control: the Z-axis vertical height adjustment loop works in position control mode, with the vertical coordinate of the dynamic lowest point as the target position and a preset support gap superimposed; the universal floating V-shaped roller of the support unit is equipped with a vertical force sensor. When the support force detected by the vertical force sensor is greater than the target support force corresponding to the unit length self-weight of the pipe, it is determined to be a hard top interference and the Z-axis is lowered. When the support force is less than the target support force, it is determined to be an empty support and the Z-axis is raised, so that the support force is maintained near the target support force. The support unit only bears the vertical self-weight of the pipe and does not apply lateral constraint load.

[0035] In one possible embodiment, firstly, the Z-axis vertical height adjustment loop of each group of three-axis servo-driven support units operates in position control mode. The vertical coordinates of the dynamic lowest point obtained by the servo-driven support control unit are the target position, and a preset support gap (i.e., a slight contact margin between the roller and the pipe surface) is superimposed on this target position to generate a Z-axis position command, so that the omnidirectional floating V-shaped roller geometrically reaches the support position below the lowest point of the pipe. Then, a vertical force sensor is installed at the support part of the omnidirectional floating V-shaped roller. The vertical force sensor is a force detection element installed between the roller support and the Z-axis slide to detect the vertical support force borne by the roller in real time. The system calculates the target support force based on the self-weight of the pipe per unit length (determined by the pipe diameter, wall thickness, and material density) and the length of the pipe section in the unit's jurisdiction. The target support force is the component of the self-weight of the pipe that the unit should bear. The measured support force is then compared with the target support force and a closed-loop correction is performed: when the measured support force is greater than the target support force, it indicates that the idler roller is too high, creating a rigid upward push on the pipe. The follow-up support control unit adjusts the Z-axis downward until the support force returns to near the target support force; when the measured support force is less than the target support force, it indicates that the idler roller is too low and is not effectively contacting the pipe. The follow-up support control unit adjusts the Z-axis upward until the support force rises to near the target support force. Finally, the omnidirectional floating V-shaped idler roller itself has omnidirectional floating capability. The omnidirectional floating means that the roller surface can freely swing with the pipe surface, allowing the pipe to slide axially on the idler roller, rotate around its own axis, and tilt and deflect at multiple angles in space without obstruction or scraping. The following movement of the X and Y axes only allows the idler roller to track the lowest point projection position on the horizontal plane, without applying a lateral clamping force to the pipe, so that the support unit only bears the vertical weight of the pipe without applying any lateral constraint load.

[0036] By using a force / position hybrid closed-loop control system with the Z-axis position ring as the reference and feedback from the vertical force sensor as the correction, the technical effect of precisely maintaining the support force of the idler roller at the weight of the pipe is achieved. Through bidirectional correction of hard top adjustment and empty support adjustment, and a universal floating idler roller structure, the technical effect of eliminating both empty support and hard top interference, and allowing the pipe to slide and rotate freely without lateral constraints is achieved.

[0037] In the embodiments of this application, the step of outputting a descent avoidance command when the pipe enters the rotation process includes: parsing the current bending process sequence; at a preset lead time before the feeding rotation mechanism executes the pipe rotation command; outputting a Z-axis descent command to all support units, with the descent range being a preset safety avoidance gap; blocking the Z-axis position command output of each support unit during the execution of the rotation command; and after detecting a signal that the pipe rotation angle has reached its position and the pipe attitude angular velocity is lower than a stable threshold for a preset duration, releasing the block and outputting a reset follow command recalculated according to the dynamic lowest point.

[0038] In one possible embodiment, firstly, the multi-axis linkage controller parses the bending sequence of the current pipe fitting. This bending sequence refers to a list of feeding, rotation, and bending steps arranged in the bending order, where each rotation step is marked with its rotation angle and execution time. At a preset lead time before the feeding rotation mechanism executes the pipe rotation command, the multi-axis linkage controller outputs a Z-axis descent command to all three-axis servo-driven support units. Each unit's Z-axis synchronously descends a preset safety clearance, causing the omnidirectional floating V-shaped roller to detach from the pipe surface. Then, during the execution of the pipe rotation command, the servo-driven support control unit blocks the Z-axis position command output of each support unit. This blocking means pausing the real-time refresh of the Z-axis position command and the force closed-loop correction, keeping the roller stationary in a safe position after descent. This prevents the roller from being squeezed or jammed against the pipe surface during sudden changes in the pipe's rotation posture. At this time, the pipe's own weight is temporarily borne by the clamping chuck during the brief period of the rotation step. Because the clearance is small and the rotation step is short, it does not affect the forming accuracy. The system then detects the completion conditions of the rotation: the encoder of the infinite-position servo rotation mechanism provides feedback on the tube's rotation angle reaching the target position, while the attitude detection element installed on the chuck or rotation mechanism provides feedback on the tube's attitude angular velocity. When the rotation angle is reached and the attitude angular velocity is below the stability threshold for a preset duration (i.e., the tube has stopped twisting and shaking and the attitude is stable), the rotation process is considered complete. Finally, the follow-up support control unit releases the Z-axis following lock, and outputs a reset following command with the target being the three-dimensional coordinates of the dynamic lowest point recalculated at the release moment. Each support unit's Z-axis rises back to the support position and restores the force / position hybrid closed-loop support, then proceeds to the next bending step.

[0039] By employing a timing-based avoidance logic of descent before rotation, blocking and following during rotation, and resetting after attitude stabilization, the technical effect of completely non-interference between the support action and the rotation action when the pipe rotates to switch to the bending plane is achieved. By using the stability of attitude angular velocity as the reset criterion, the technical effect of smooth support and no impact or jamming after avoidance is achieved.

[0040] In the embodiments of this application, a support unit scheduling step based on the total forming length of the pipe fitting is further included: the total forming length of the pipe fitting is calculated according to the three-dimensional centerline model of the pipe fitting; when the total forming length does not exceed the pipe length boundary threshold, it is determined to be a short pipe condition, and only the number of support units required to cover the forming pipe segment is activated and operated according to the first set of speed parameters and the first clearance gap; when the total forming length exceeds the pipe length boundary threshold, it is determined to be a long pipe condition, all support units are activated to work together, and they are operated according to the second set of speed parameters lower than the first set of speed parameters and the second clearance gap greater than the first clearance gap, and real-time monitoring of the deflection of the forming pipe segment is started; when the monitored deflection exceeds the deflection warning threshold, a deflection over-limit warning signal is output.

[0041] In one possible embodiment, firstly, the follow-up support control unit accumulates the length of each pipe segment according to the preloaded three-dimensional centerline model of the pipe fitting, and calculates the total forming length of the pipe fitting. The total forming length refers to the total unfolded length of the pipe fitting from the first end to the last end along the centerline, which determines the maximum scale of the suspended pipe segment during the processing. Then, the total forming length is compared with the preset pipe length threshold, and the operating conditions are switched: when the total forming length does not exceed the threshold, it is determined to be a short pipe condition. At this time, the pipe weight is small and the deflection is controllable. The system only activates the number of support units required to cover the forming pipe section, shuts down redundant units, and operates according to the first set of speed parameters (higher bending and feeding speed) and the first clearance gap (smaller support clearance gap) to optimize processing efficiency. When the total forming length exceeds the threshold, it is determined to be a long pipe condition. At this time, the pipe weight is heavy and the formed pipe section is prone to shaking. The system activates all support units to work together, operates according to the second set of speed parameters lower than the first set of speed parameters and the second clearance gap greater than the first clearance gap, and ensures that the pipe section span between any adjacent support units does not exceed the preset maximum span, thus preventing large span suspensions from the layout. Then, in the long pipe condition, real-time monitoring of the forming pipe section deflection is activated: the system estimates the actual deflection of the pipe section based on the historical trajectory of the dynamic lowest point coordinates and the pipe weight model. The deflection refers to the vertical deviation of the actual position of the pipe section relative to the ideal centerline. Finally, when the monitored deflection exceeds the deflection warning threshold, the system outputs a deflection over-limit warning signal through the human-machine interface unit, prompting the operator to intervene or automatically reducing the operating speed; when the deflection is normal, processing continues until all bends are formed. In addition, the distance between the outlet of the bending forming host and the first set of follow-up support units is controlled in the equipment layout within a preset distance range of one to several times the pipe diameter, so as to avoid the area where the stress at the pipe bending outlet is not yet stable and prevent the support reaction force from interfering with the bending accuracy and springback stability.

[0042] By automatically switching between long and short pipe working conditions based on the total forming length of the pipe fitting, starting and stopping the support unit as needed, and matching differentiated speeds and clearances, the technical effect of achieving both efficient processing of short pipes and deformation prevention of long pipes is achieved. Through real-time monitoring of deflection and over-limit warning in long pipe working conditions, the technical effect of actively suppressing plastic sagging deformation of long-sized spatial pipe fittings is achieved.

[0043] In the embodiments of this application, the springback compensation coefficient is corrected online in the following manner: a bending angle detection unit is set at the bending forming mechanism, and the actual bending angle of the pipe is detected after each bending, and the springback deviation angle of that bending is calculated: ,in The springback deviation angle, This is the bending angle command value. The actual bending angle is measured by the bending angle detection unit; the bending angle command for the next bend is executed according to the corrected command angle. ;in This is the command for the corrected bending angle of the next bend. The target bending angle for the next bend; and the springback deviation angle. Iteratively correct the springback compensation coefficient corresponding to the pipe parameters in the pipe process database.

[0044] In one possible embodiment, firstly, a bending angle detection unit is installed in the bending forming host module. This unit is an angle encoder mounted on the rotating shaft of the bending die or the bending actuator, used to detect the actual bending angle of the pipe after each bending is completed and the die is depressurized. Then, after each bending is completed, the bending servo control unit reads the bending angle command value of the elbow. The actual bending angle measured by the bending angle detection unit Calculate the springback deviation angle for this bend: ,in This is the springback deviation angle, which is the amount of angle lost due to springback during this bend. This is the bending angle command value. This is the actual bending angle. Then, the bending angle command for the next bend is corrected: the target bending angle for the next bend is adjusted. Superimposed on the previous measured rebound deviation angle The corrected bending angle command is obtained: ,in This is the command for the corrected bending angle of the next bend. The target bending angle for the next bend; the system according to The driving bending and forming mechanism brings the actual angle of the tube after springback to the target bending angle. Finally, the bending servo control unit uses the springback deviation angle... Using samples, the springback compensation coefficients corresponding to the pipe parameters (such as pipe diameter, wall thickness, material, and bending radius) in the pipe process database are iteratively corrected. The iterative correction adopts a successive cumulative update method, so that the compensation coefficients in the database continuously approach the actual springback of the pipe with each processing batch. The corrected compensation coefficients are also used to generate bending commands, forming a two-layer springback control of prior database compensation and online measurement correction.

[0045] By measuring the springback deviation angle of each bend using a bending angle detection unit and superimposing compensation on the command for the next bend, the technical effect of the bending angle converging to the target value for each bend is achieved. By iteratively updating the compensation coefficient of the process database with the measured springback amount, the technical effect of continuously optimizing the springback compensation accuracy with processing and adapting to the performance fluctuations of different batches of materials is achieved.

[0046] In the embodiments of this application, in the multi-axis linkage control step, the infinite-position servo rotation mechanism of the feeding rotation mechanism is connected to the power supply and control bus via a conductive slip ring. The conductive slip ring continuously transmits power and encoder feedback signals during the 360° continuous rotation of the chuck. The real-time bus is an industrial real-time fieldbus, and the axial feeding command, pipe rotation command, bending command, and support following command are all issued with the same synchronous clock flag. Furthermore, the multi-axis linkage controller performs overload monitoring on the servo motor torque of the feeding rotation mechanism and the bending force of the bending forming mechanism. When the torque or bending force exceeds its respective protection threshold, the corresponding servo enable is cut off and an overload alarm is output.

[0047] In one possible embodiment, firstly, the clamping chuck in the servo feeding rotation module is driven by an infinite-position servo rotation mechanism, which can rotate continuously around the pipe axis to switch any bending plane. To solve the power supply and signal transmission problem of the rotating component, the power supply and control bus on the fixed side are connected to the rotating side via a conductive slip ring. The conductive slip ring is an annular sliding contact assembly composed of a fixed ring body and a rotating brush bundle, which is installed on the rotation axis of the rotation mechanism. Its fixed end is connected to the power supply and control bus, and its rotating end rotates with the frame and is connected to the servo and encoder on the chuck side. During the continuous rotation of the chuck, the conductive slip ring continuously transmits power and encoder feedback signals, so that the pipe rotation angle can be read in real time and the rotation servo is continuously powered, without the need for zeroing or reversing the winding. Then, the multi-axis linkage controller is connected to the servo moving carriage driver, the infinite-position servo rotating mechanism, the bending servo control unit, and the follow-up support control unit via an industrial real-time fieldbus. Axial feeding commands, pipe rotation commands, bending commands, and support following commands are all issued carrying the same synchronization clock marker. This synchronization clock marker is a unified timestamp added to each command frame by the real-time bus distributed clock mechanism. Each slave servo driver executes synchronously according to this timestamp, ensuring strict alignment of the feeding, rotation, bending, and support following actions. Overload monitoring is then performed on the two types of power outputs: for the servo feeding and rotating module, the output torque of the feeding and rotation servo motors is monitored; for the bending forming main module, the bending force feedback signal is monitored. When the torque exceeds the torque protection threshold of the corresponding motor, or the bending force exceeds the limit protection threshold of the corresponding pipe, an overload is determined. Finally, the system immediately cuts off the enable output of the corresponding servo axis (i.e., cancels the power enable signal of the servo driver, causing the axis to stop outputting power), and outputs an overload alarm through the human-machine interface unit. The overload alarm includes the axis number where the overload occurred, the time of the overload, and the overload amount, for the operator to troubleshoot. Processing can only be restarted after the fault is resolved and reset. This dual overload protection is especially for working conditions with high power demand when bending thick-walled alloy pipes, preventing equipment damage from overload and pipe crushing and scrapping.

[0048] By continuously supplying power and transmitting signals during the infinite rotation of the chuck using conductive slip rings, the technical effect of switching the plane at any angle of pipe rotation without wire entanglement is achieved; by issuing four types of motion commands through a real-time bus unified synchronous clock, the technical effect of strictly aligning the multi-axis actions of feeding, rotation, bending, and support at all times and achieving continuous forming without cumulative deviation is achieved; and by implementing dual overload monitoring and cut-off protection of torque and bending force, the technical effect of active safety protection for equipment and pipe under abnormal working conditions is achieved.

[0049] Example 2:

[0050] Reference Figure 2 This application also provides an adaptive control system for a CNC spatial pipe bending machine, including a parameter management unit, a bending servo control unit, a follow-up support control unit, a multi-axis linkage controller, a data storage unit, and a human-machine interaction unit. The parameter management unit is connected to the human-machine interaction unit and the data storage unit, and is used to receive pipe parameters manually entered or obtained from 3D CAD drawings and write them into the data storage unit. The bending servo control unit is connected to the multi-axis linkage controller and the data storage unit, and is used to query the pipe process database based on the pipe parameters to generate bending thrust commands, bending speed commands, and springback compensation coefficients, drive the servo electric bending actuator and hydraulic clamping assembly of the bending forming mechanism, and receive bending force feedback signals to execute limit threshold shutdown protection. The follow-up support control unit is connected to the multi-axis linkage controller, and its output is connected to the X-axis, Y-axis, and Z-axis servo drivers of multiple sets of three-axis servo follow-up support units for preloading. The system uses a 3D centerline model of the pipe fitting and real-time discrete solution to calculate the 3D coordinates of the dynamic lowest point of the formed pipe segment. It independently outputs position commands to each support unit and outputs descent and reset / follow commands during the pipe rotation process. The multi-axis linkage controller is connected via an industrial real-time fieldbus to the servo-driven trolley driver of the feeding and rotating mechanism, the infinite-position servo rotating mechanism, the bending servo control unit, and the follow-up support control unit. It issues axial feeding commands, pipe rotation commands, bending commands, and support follow commands at the same synchronous clock. The infinite-position servo rotating mechanism is connected to the power supply and control bus via a conductive slip ring. The data storage unit is connected to the parameter management unit, the bending servo control unit, and the follow-up support control unit, respectively, to store the pipe process database, the 3D centerline model of the pipe fitting, and operating status data. The human-machine interface unit is connected to the parameter management unit and the multi-axis linkage controller for parameter input, status display, and alarm output.

[0051] In one possible embodiment, firstly, the parameter management unit is connected to the human-machine interaction unit and the data storage unit respectively: the parameter management unit receives manually entered pipe parameters through the human-machine interaction unit, or receives imported 3D CAD drawing files and parses them to obtain pipe parameters, verifies them, and writes the pipe parameters into the data storage unit; the human-machine interaction unit also handles status display and alarm output. Then, the bending servo control unit is connected to the multi-axis linkage controller and the data storage unit: the bending servo control unit reads pipe parameters from the data storage unit and queries the pipe process database, generates bending thrust commands, bending speed commands, and springback compensation coefficients, and outputs them to the servo electric push bending actuator and hydraulic clamping assembly of the bending forming host module; at the same time, it receives bending force feedback signals and bending angle detection unit signals, and executes limit threshold shutdown protection and online springback compensation. The servo support control unit is then connected to the multi-axis linkage controller, and its output is connected to the X-axis, Y-axis, and Z-axis servo drives of multiple sets of three-axis servo servo servo servo support units. The servo support control unit reads the three-dimensional centerline model of the pipe from the data storage unit, solves the three-dimensional coordinates of the dynamic lowest point in real time, outputs X, Y, and Z position commands independently to each support unit, and executes a force / position hybrid closed loop. During the rotation process, it outputs descent avoidance and reset follow commands, and performs support unit scheduling and deflection monitoring according to the total forming length of the pipe. The multi-axis linkage controller is connected to the servo moving carriage driver, the infinite position servo rotation mechanism, the bending servo control unit, and the servo support control unit via an industrial real-time fieldbus. It issues axial feeding commands, pipe rotation commands, bending commands, and support follow commands according to the same synchronous clock. The infinite position servo rotation mechanism is connected to the power supply and control bus via a conductive slip ring. The multi-axis linkage controller simultaneously receives torque and bending force overload feedback and executes cut-off enable and alarm protection. Finally, the data storage unit is connected to the parameter management unit, bending servo control unit, and follow-up support control unit, respectively, to store the pipe process database, the three-dimensional centerline model of the pipe fitting, and the operating status data; the human-machine interaction unit is connected to the parameter management unit and the multi-axis linkage controller to complete parameter input, operating status display, and various alarm outputs. When the machine is working, the feeding and storage module supports the straight pipe to be processed, the servo feeding and rotation module completes feeding, clamping, and rotation, the bending and forming main module completes adaptive bending, and the three-axis follow-up support module supports the weight of the formed pipe section. All actions are completed collaboratively by the above systems under a force-load separation configuration.

[0052] Through the clear division of labor and bus interconnection of six units—parameter management, bending servo control, follow-up support control, multi-axis linkage control, data storage, and human-machine interaction—the integrated system achieves the technical effect of adaptive matching of pipe parameters, dynamic follow-up support, timing avoidance, and multi-axis synchronous linkage. Through the complete configuration of the connection relationship and data flow between each unit and the actuator, the reliable implementation of each step of the method on the hardware system and the technical effect of modular operation and maintenance are achieved.

[0053] The optional embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the embodiments of the present invention are not limited to the specific details in the above embodiments. Within the scope of the technical concept of the embodiments of the present invention, various simple modifications can be made to the technical solutions of the embodiments of the present invention, and these simple modifications all fall within the protection scope of the embodiments of the present invention.

[0054] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the embodiments of the present invention will not describe the various possible combinations separately.

[0055] Furthermore, various different implementations of the present invention can be combined arbitrarily, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed in the present invention.

Claims

1. An adaptive control method for a CNC spatial tube bending machine, applied to a CNC spatial tube bending machine including a feeding rotation mechanism and a bending forming mechanism, characterized in that, The pipe bending machine also includes a three-axis servo-driven support unit, and the method includes: Parameter acquisition steps: Obtain pipe parameters including pipe diameter, wall thickness, material, and bending radius; Adaptive bending control steps: Based on the pipe parameters, query the pipe process database to determine the bending thrust command, bending speed command and springback compensation coefficient, drive the bending forming mechanism to perform three-dimensional bending, and collect the bending force feedback signal. When the bending force exceeds the pipe's limit protection threshold, output a shutdown protection signal. Follow-up support control steps: Preload the three-dimensional centerline model of the pipe fitting, solve the three-dimensional coordinates of the dynamic lowest point of the formed pipe section in real time, output position commands independently to each three-axis servo follow-up support unit, track the lowest point of the pipe in the jurisdiction and only bear the vertical self-weight of the pipe; when the pipe enters the rotation process, output the descent avoidance command, and output the reset follow command after the rotation is completed and the attitude is stable. Multi-axis linkage control steps: Feeding, rotation, bending and support following instructions are output synchronously via real-time bus, enabling each mechanism to work together to complete three-dimensional continuous bending; the weight of the pipe is borne by the follow-up support unit, and the chuck only transmits clamping force, feeding force and torsional torque.

2. The adaptive control method for a CNC spatial pipe bending machine according to claim 1, characterized in that, The parameter acquisition step includes dual-mode parameter input: in response to a manual input command, the pipe parameters input via the human-computer interaction unit are received; or, in response to a drawing import command, a 3D CAD pipe fitting drawing file is read, the drawing file containing geometric data of the pipe fitting centerline and a pipe fitting details table, the geometric data of the pipe fitting centerline is parsed and the pipe diameter, wall thickness, bending radius, and bending angle and bending plane angle of each bend are extracted to generate the pipe parameters; and the parsing results are cross-validated with the pipe fitting details table in the drawing, and a parameter alarm is output when the verification is inconsistent.

3. The adaptive control method for a CNC spatial pipe bending machine according to claim 1, characterized in that, The step of determining the bending thrust command by querying the pipe process database based on pipe parameters includes: calculating the theoretical bending thrust based on pipe diameter, wall thickness, material, and bending radius. ； in For theoretical bending thrust, This is a correction factor related to the material. The yield strength of the pipe material. For pipe wall thickness, The outer diameter of the pipe. The bending radius is given. Based on the theoretical bending thrust, the bending speed ratio coefficient and the springback compensation coefficient are determined by querying the pipe process database according to the material type: a lower bending thrust is used in combination with a higher bending speed for carbon steel, and a higher bending thrust is used in combination with a lower bending speed for alloy heat-resistant steel. The bending thrust command is generated by limiting the theoretical bending thrust according to the rated output range of the servo electric bending actuator.

4. The adaptive control method for a CNC spatial pipe bending machine according to claim 1, characterized in that, The real-time discrete solution of the three-dimensional coordinates of the dynamic lowest point of the formed pipe segment includes: discretizing the three-dimensional centerline model of the pipe into several model points at a preset step size; performing coordinate transformation on each model point according to the bending angle and feeding length of the completed bending process to obtain the real-time pose of the formed pipe segment in the equipment coordinate system; for each support unit, in the subset of model points corresponding to its jurisdiction, taking the model point with the smallest vertical coordinate as the dynamic lowest point tracked by the support unit, and generating three position commands for the support unit: X-axis feeding follow, Y-axis lateral offset compensation, and Z-axis vertical height adjustment; wherein the real-time pose of the formed pipe segment in the equipment coordinate system is updated by the following formula: ； in The coordinates of the point in the local coordinate system of the pipe fitting are given. These are the coordinates in the device coordinate system after the transformation. Let be the rotation matrix that rotates the pipe around the Z-axis of the equipment by the rotation angle β. Let be the rotation matrix for the bending angle α around the Y-axis of the equipment. Let L be the translation vector along the axial feeding length L.

5. The adaptive control method for a CNC spatial pipe bending machine according to claim 4, characterized in that, The position command output to the three-axis servo-driven support unit adopts force / position hybrid control: the Z-axis vertical height adjustment loop works in position control mode, with the vertical coordinate of the dynamic lowest point as the target position and a preset support gap superimposed; the universal floating V-shaped roller of the support unit is equipped with a vertical force sensor. When the support force detected by the vertical force sensor is greater than the target support force corresponding to the unit weight of the pipe, it is determined to be a hard top interference and the Z-axis is lowered. When the support force is less than the target support force, it is determined to be an empty support and the Z-axis is raised, so that the support force is maintained near the target support force. The support unit only bears the vertical weight of the pipe and does not apply lateral constraint load.

6. The adaptive control method for a CNC spatial pipe bending machine according to claim 1, characterized in that, The step of outputting a descent avoidance command when the pipe enters the rotation process includes: parsing the current bending process sequence; at a preset lead time before the feeding rotation mechanism executes the pipe rotation command; outputting a Z-axis descent command to all support units, with the descent range being a preset safety avoidance gap; blocking the Z-axis position command output of each support unit during the execution of the rotation command; and after detecting a signal that the pipe rotation angle has reached its position and the pipe's attitude angular velocity is lower than a stable threshold for a preset duration, releasing the block and outputting a reset follow command recalculated based on the dynamic lowest point.

7. The adaptive control method for a CNC spatial pipe bending machine according to claim 1, characterized in that, It also includes a support unit scheduling step based on the total forming length of the pipe fitting: the total forming length of the pipe fitting is calculated according to the three-dimensional centerline model of the pipe fitting. When the total forming length does not exceed the pipe length boundary threshold, it is determined to be a short pipe condition. Only the number of support units required to cover the forming pipe section is activated and they operate according to the first set of speed parameters and the first clearance gap. When the total forming length exceeds the pipe length boundary threshold, it is determined to be a long pipe condition. All support units are activated to work together and operate according to the second set of speed parameters lower than the first set of speed parameters and the second clearance gap greater than the first clearance gap. Real-time monitoring of the deflection of the forming pipe section is also started. When the monitored deflection exceeds the deflection warning threshold, a deflection over-limit warning signal is output.

8. The adaptive control method for a CNC spatial pipe bending machine according to claim 3, characterized in that, The springback compensation coefficient is corrected online in the following way: A bending angle detection unit is set at the bending forming mechanism. After each bending is completed, the actual bending angle of the pipe is detected, and the springback deviation angle of that bending is calculated: ,in The springback deviation angle, This is the bending angle command value. The actual bending angle is measured by the bending angle detection unit; the bending angle command for the next bend is executed according to the corrected command angle. ； in This is the command for the corrected bending angle of the next bend. The target bending angle for the next bend; and the springback deviation angle. Iteratively correct the springback compensation coefficient corresponding to the pipe parameters in the pipe process database.

9. The adaptive control method for a CNC spatial pipe bending machine according to claim 1, characterized in that, In the multi-axis linkage control steps, the infinite-position servo rotation mechanism of the feeding rotation mechanism is connected to the power supply and control bus via a conductive slip ring. The conductive slip ring continuously transmits power and encoder feedback signals during the 360° continuous rotation of the chuck. The real-time bus is an industrial real-time fieldbus, and axial feeding commands, pipe rotation commands, bending commands, and support following commands are all issued with the same synchronous clock flag. Furthermore, the multi-axis linkage controller performs overload monitoring on the servo motor torque of the feeding rotation mechanism and the bending force of the bending forming mechanism. When the torque or bending force exceeds its respective protection threshold, the corresponding servo enable is cut off and an overload alarm is output.

10. An adaptive control system for a CNC spatial pipe bending machine, used to implement the adaptive control method for a CNC spatial pipe bending machine according to any one of claims 1 to 9, characterized in that, It includes a parameter management unit, a bending servo control unit, a follow-up support control unit, a multi-axis linkage controller, a data storage unit, and a human-machine interaction unit; The parameter management unit is connected to the human-computer interaction unit and the data storage unit, and is used to receive pipe parameters manually entered or obtained from the analysis of three-dimensional CAD drawings and write them into the data storage unit. The bending servo control unit is connected to the multi-axis linkage controller and the data storage unit. It is used to query the pipe process database according to the pipe parameters to generate bending thrust command, bending speed command and springback compensation coefficient, drive the servo electric push bending actuator and hydraulic clamping assembly of the bending forming mechanism, and receive bending force feedback signal to execute limit threshold shutdown protection. The follow-up support control unit is connected to the multi-axis linkage controller. Its output terminal is connected to the X-axis, Y-axis and Z-axis servo drivers of multiple sets of three-axis servo follow-up support units. It is used to preload the three-dimensional centerline model of the pipe fitting, solve the three-dimensional coordinates of the dynamic lowest point of the formed pipe segment in real time, output position commands to each support unit independently, and output descent avoidance command and reset follow command during the pipe rotation process. The multi-axis linkage controller is connected to the servo moving carriage driver of the feeding and rotating mechanism, the infinite position servo rotating mechanism, the bending servo control unit, and the follow-up support control unit via an industrial real-time fieldbus. It is used to issue axial feeding commands, pipe rotation commands, bending commands, and support following commands according to the same synchronous clock. The infinite position servo rotating mechanism is connected to the power supply and the control bus via a conductive slip ring. The data storage unit is connected to the parameter management unit, the bending servo control unit, and the follow-up support control unit, respectively, and is used to store the pipe process database, the three-dimensional centerline model of the pipe fitting, and the operating status data; the human-machine interaction unit is connected to the parameter management unit and the multi-axis linkage controller, and is used for parameter input, status display, and alarm output.

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