Cutting equipment for pipeline prefabrication

Abstract

The invention discloses cutting equipment for pipeline prefabrication, belongs to the technical field of machining, and is mainly used for solving the problems of insufficient cutting precision and poor machining stability caused by clamping force fluctuation, pipeline ovality abnormity and dynamic path offset in the pipeline cutting process. According to the equipment, high-precision cutting is achieved through cooperative work of the rack, the clamping mechanism, the cutting executing mechanism, the driving motor and the control module, the clamping mechanism is provided with a pressure sensor to monitor fluctuation of clamping force, and the driving motor is a servo motor with an absolute value encoder to precisely control the rotating angle of a pipeline. The cutting executing mechanism feeds back the displacement track of the cutting machine in real time through a displacement sensor. Synchronous control logic is arranged in the control module, when the fluctuation of the clamping force exceeds the limit, the rotating speed of the servo motor is automatically reduced, the cutting machine is paused, meanwhile, a path correction algorithm is configured, and the proportional relation between the axial moving speed and the radial feeding amount of the cutting machine is calculated in real time based on encoder angle data. And the notch precision and the machining efficiency can be obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical processing, and in particular relates to a cutting device for pipeline prefabrication processing. Background Art

[0002] In the field of pipe prefabrication, traditional cutting equipment commonly suffers from issues such as insufficient clamping stability, delayed path correction, and poor ellipticity adaptability, which directly impact cutting accuracy and processing efficiency. Specifically, existing clamping mechanisms rely on a fixed pressure threshold to control clamping force. However, hydraulic systems are prone to pressure drift due to oil temperature fluctuations, seal wear, or load fluctuations, resulting in unstable clamping force.

[0003] This fluctuation is particularly significant during long-term continuous processing, which may cause the pipe to slip or locally deform, resulting in a deviation in the cutting trajectory. Although existing technologies attempt to monitor the clamping force through pressure sensors, they lack a real-time closed-loop adjustment mechanism and cannot quickly adjust the hydraulic pump output when the clamping force exceeds the limit, resulting in compensation delays. In addition, pipes are prone to elliptical deformation due to material stress release or external extrusion during transportation or storage, and traditional cutting equipment relies on preset paths or single displacement sensor feedback, making it difficult to dynamically adapt to different ovality. When the pipe cross-section deviates from the standard circle, the axial movement speed and radial feed rate of the cutting machine are out of proportion, resulting in the accumulation of incision position deviations. Existing path correction algorithms mostly use a global continuous calculation mode, which has a large amount of data processing and limited response speed, and cannot achieve millisecond-level correction under high-speed rotation conditions.

[0004] For example, when the pipe rotates at a speed of tens of revolutions per minute, traditional algorithms have difficulty in correcting trajectory errors in a timely manner due to the long calculation cycle, and the deviation is amplified as the processing time increases. At the same time, the control logic of the servo motor and the cutting machine's moving mechanism lacks deep coordination, and the speed adjustment and feed rate matching accuracy are insufficient. During the acceleration or deceleration stage of the motor, the feed action of the cutting machine cannot respond synchronously due to the inertia of the mechanical transmission or nonlinear friction resistance, which can easily cause trajectory overshoot or oscillation. Such problems are more prominent in the processing of thin-walled pipes or high-hardness materials. In severe cases, they may cause tool damage or workpiece scrapping. Existing technologies attempt to improve accuracy by increasing the number of sensors or optimizing local control strategies, but the low efficiency of multi-source data fusion and the high complexity of dynamic modeling remain the main bottlenecks.

[0005] For example, timing alignment errors between encoder angle data and displacement sensor feedback may cause phase lag in the correction command, further exacerbating path deviation. In addition, the system needs to maintain processing efficiency while ensuring high-precision control. Frequent correction actions may increase the computing load and lead to a decrease in overall response speed. The root cause of these problems lies in the technical limitations of existing equipment in dynamic perception, real-time decision-making, and multi-mechanism collaborative control. A comprehensive solution that can balance stability, precision, and efficiency is urgently needed. Summary of the Invention

[0006] One object of the present invention is to solve the problems of low cutting accuracy and poor processing stability caused by the fluctuations in clamping force, lag in path correction, and insufficient dynamic cooperative control of traditional pipe cutting equipment, especially the significant error accumulation under the conditions of elliptical pipes or high-speed rotation.

[0007] Solve the problems that the coaxial alignment of the existing clamping mechanism is poor and the clamping force distribution is uneven, which easily causes pipe sliding or local deformation, resulting in cutting trajectory deviation.

[0008] Solve the problem that the traditional dynamic compensation algorithm lacks the correlation model between the clamping force and the rotation angle, resulting in the disconnection between the axial speed adjustment of the cutting machine and the clamping state and insufficient compensation accuracy.

[0009] Solve the problem that there is a lack of dynamic cooperation between the pulse control of the servo motor and the start-stop logic of the cutting machine, and the response lags when overloaded or the position deviates, which easily causes equipment damage or processing interruption.

[0010] Solve the problem that the existing pressure fluctuation response mechanism is single and cannot perform hierarchical control according to the fluctuation level, resulting in poor balance between processing efficiency and safety.

[0011] Solve the problem that the calculation efficiency of the continuous path correction algorithm is low and it cannot meet the real-time error compensation requirements of high-speed rotating pipes, resulting in serious deviation accumulation.

[0012] Solve the problem that the traditional pressure fluctuation threshold is fixed and cannot dynamically adapt to the working condition changes in different processing cycles, resulting in a high risk of false triggering or missed judgment.

[0013] Solve the problem that the global path correction mode cannot finely process local deformations, resulting in insufficient compensation accuracy of the cutting trajectory of elliptical pipes.

[0014] Solve the problem that the existing path correction algorithm lacks a segmented verification and prediction switching mechanism, and the correction response lags in abnormal states, resulting in poor processing continuity.

[0015] Solve the problem that the traditional ellipticity compensation depends on the feedback of a single sensor and cannot distinguish normal fluctuations from abnormal deformations, resulting in a high degree of blindness in compensation actions.

[0016] The present invention provides a cutting device for pipe prefabrication processing, including a frame, a clamping mechanism, a cutting execution mechanism, a driving motor, and a control module; the clamping mechanism includes a pressure sensor; the driving motor is a servo motor with an absolute encoder; the cutting execution mechanism includes a displacement sensor; the control module includes a PLC controller and a human-machine interface. The PLC controller is connected to the pressure sensor and the displacement sensor through analog input ports, controls the rotation speed of the servo motor through a pulse output port, and controls the start and stop of the cutting machine through a digital output port; the PLC controller has a built-in synchronous control logic. When the pressure sensor detects that the clamping force fluctuation exceeds the set range, the rotation speed of the servo motor is synchronously reduced to a preset safety value and a pause instruction for the cutting machine is triggered; the control module is configured with a path correction algorithm to calculate the proportional relationship between the axial movement speed and the radial feed of the cutting machine in real time according to the pipe rotation angle data fed back by the servo motor encoder; the human-machine interface displays the clamping force numerical curve, the pipe rotation angle coordinates, and the displacement trajectory of the cutting machine in real time, and stores the peak clamping force and the number of path corrections for each cutting process; a motion correlation model is established between the moving mechanism of the cutting machine and the servo motor. When the pipe ovality causes abnormal readings of the displacement sensor of the cutting machine, the feed rate of the moving mechanism is dynamically adjusted according to the encoder angle data.

[0017] Preferably, the clamping mechanism of the present invention includes two groups of coaxially arranged chucks. The two groups of chucks are fixed on the working table of the frame through an adjustable-spacing mounting seat, and a pressure sensor is embedded inside each chuck; a pressure closed-loop adjustment unit is provided in the opening and closing control circuit of the chuck. When the deviation between the detection value of the pressure sensor and the set value continuously exceeds 5 seconds, the hydraulic pump pressure compensation program is automatically started until the pressure is stabilized within the tolerance band; the driving motor is a servo motor with an absolute encoder, and the output shaft of the servo motor is rigidly connected to the rotating spindle of one of the groups of chucks through a coupling; the cutting execution mechanism includes a disc-type cutting machine that can move radially along the pipe, and a displacement sensor is installed on the moving mechanism of the cutting machine. The detection direction of the displacement sensor is consistent with the movement direction of the cutting machine.

[0018] Preferably, the PLC controller of the present invention is built-in with a dynamic compensation algorithm, which establishes a linear correlation model between the real-time clamping force fluctuation value detected by the pressure sensor and the pipeline rotation angle data fed back by the servo motor encoder, and outputs a compensation coefficient of the axial movement speed of the cutting machine to the moving mechanism of the cutting machine; the human-machine interface is provided with a data synchronous display unit, which parallelly displays a clamping force fluctuation curve, the real-time rotation speed value of the servo motor, and the trajectory model of the displacement trajectory of the cutting machine on the touch screen interface; when the dynamic compensation algorithm detects that the clamping force fluctuation exceeds the set threshold, it generates a segmented decreasing instruction sequence of the radial feed amount of the cutting machine according to the current rotation speed of the servo motor; a speed closed-loop control link is established between the PLC controller and the servo motor driver, and when the displacement sensor of the cutting machine detects the deviation amount between the actual displacement and the calculated path, the angular acceleration compensation value of the servo motor is adjusted in reverse.

[0019] Preferably, a dynamic frequency modulation unit is provided between the pulse output port of the PLC controller of the present invention and the servo motor driver, and this unit dynamically adjusts the output pulse frequency according to the clamping force data detected by the pressure sensor in real time. The adjustment range of the pulse frequency is limited to 70%-130% of the reference frequency corresponding to the rated speed of the servo motor; the digital output port is configured with a start-stop safety interlock logic. When the displacement sensor detects that the initial position of the moving mechanism of the cutting machine deviates from the set origin by more than 1 mm, the start instruction of the cutting machine is automatically locked until the position is calibrated; the dynamic frequency modulation unit and the servo motor encoder establish a closed-loop feedback link, and the actual rotation speed data fed back by the encoder is processed by a proportional-integral algorithm to generate a compensation increment of the pulse frequency; the start-stop safety interlock logic integrates a delay trigger mechanism, which maintains the plasma arc for 0.5 seconds after receiving the stop instruction of the cutting machine and then cuts off the power supply, and at the same time forces the servo motor to perform a 5° angle retraction action; the pulse output port is set in an overload protection mode. When the detected value of the servo motor current continuously exceeds 120% of the rated current for 3 seconds, the pulse frequency is automatically reduced to 50% of the reference frequency and a touch screen alarm pop-up window is triggered.

[0020] Preferably, the synchronization control logic of the present invention includes a multi-level response mechanism. When the clamping force fluctuation value detected by the pressure sensor exceeds 10% of the upper limit of the set range, the rotational speed of the servo motor is linearly reduced to 80% of the preset safety value, and a cutter pause preparation signal is sent to the digital output port at the same time. When the clamping force fluctuation value continuously exceeds 15% of the upper limit of the set range for 2 seconds, the rotational speed of the servo motor is forcibly switched to 50% of the preset safety value, and an emergency stop command for the cutter is sent through the digital output port. The PLC controller continuously monitors the data of the pressure sensor during the pause of the cutter. If the clamping force fluctuation value returns to the set range within 5 seconds, the servo motor is automatically restarted and resumes operation at 90% of the original rotational speed. The synchronization control logic establishes a linkage judgment condition with the displacement sensor. When the offset of the cutter displacement trajectory exceeds twice the axial movement speed compensation coefficient, the servo motor speed reduction operation is preferentially executed and then the cutter pause is triggered. The calculation of the preset safety value is based on the average rotational speed of the last 10 processing cycles recorded by the servo motor encoder, and a dynamic rotational speed threshold is generated through conversion by the reference frequency of the pulse output port.

[0021] Preferably, the calculation process of the proportional relationship of the present invention includes a data segmentation processing module. The pipeline rotation angle fed back by the servo motor encoder is divided into independent calculation intervals every 15°. The slope parameter of the radial feed amount is dynamically corrected according to the cumulative value of the axial movement speed within each interval. The data segmentation processing module establishes a feedback verification mechanism with the displacement sensor. When the deviation between the actual radial feed amount and the calculated value exceeds 5% of the axial movement speed, a slope parameter recalculation command for the current calculation interval is automatically triggered. At the end of each pipeline rotation cycle, the PLC controller extracts the radial feed amount correction data of the last three intervals to generate a predicted reference value for the axial movement speed in the next cycle. The calculation result of the proportional relationship is converted into a control signal for the cutter moving mechanism through pulse width modulation. For every 0.1 m / s change in the axial movement speed, the pulse duty cycle is adjusted by 0.8% - 1.2%. The data segmentation processing module has an angle compensation logic built-in. When the change rate of the rotational angle acceleration in two consecutive calculation intervals is detected to exceed 0.5 rad / s², the slope parameter of the radial feed amount is forcibly locked to the moving average value of the previous three intervals.

[0022] Preferably, the synchronization control logic of the present invention sets three - level pressure fluctuation determination thresholds. The first - level threshold is 8% of the upper limit of the set range, triggering the servo - motor speed to decrease at a gradient of 2% every 0.5 seconds, and simultaneously sending a preparation pause signal to the cutting machine. The second - level threshold is 12% of the upper limit of the set range, forcibly locking the servo - motor speed at 60% of the current value, and starting a 0.3 - second buffer pause program for the cutting machine. The third - level threshold is 20% of the upper limit of the set range, immediately cutting off the servo - motor enable signal and switching the cutting - machine power supply to the standby mode. After triggering the pause instruction, the PLC controller continuously collects pressure - sensor data. If the pressure - fluctuation value drops back within the set range within 3 consecutive sampling cycles, the servo - motor is restarted at 85% of the original speed and the cutting - machine operation is resumed. During the execution of the buffer pause program, the real - time position data of the displacement sensor is read synchronously, and the position error of the axial - movement mechanism is maintained within ±0.15 mm during the cutting - machine pause. The values of the three - level pressure - fluctuation determination thresholds are dynamically updated according to the standard deviation of the clamping force in the last 5 normal processing cycles recorded by the servo - motor encoder, and the update period is automatically calibrated before each processing task starts.

[0023] Preferably, the path - correction algorithm of the present invention sets an angle - segmented calculation mechanism, dividing the pipeline rotation angle fed back by the servo - motor encoder into calculation intervals every 30°, and dynamically calculating the differential correction amount of the radial feed amount according to the real - time value of the axial - movement speed within each interval. At the end of each calculation interval, the PLC controller makes a differential comparison between the actual radial displacement detected by the displacement sensor and the calculated value. When the cumulative deviation exceeds 3% of the axial - movement speed, an inverse - correction instruction for the compensation coefficient of the next interval is automatically generated. The calculation process of the differential correction amount introduces the servo - motor speed - change - rate parameter, and multiplies the speed - acceleration value by the current value of the axial - movement speed as the dynamic adjustment factor of the radial feed amount. The path - correction algorithm establishes a real - time verification link with the cutting - machine displacement sensor. After the axial - movement mechanism completes a 2 - mm stroke each time, a position - calibration operation of the radial feed amount is forcibly triggered. The angle - segmented calculation mechanism has built - in abnormal - data processing logic. When the pipeline - rotation - angle increment deviation in three consecutive calculation intervals exceeds 5°, it automatically switches to a prediction - calculation mode based on the average angular velocity of the previous five intervals.

[0024] Preferably, the path correction algorithm of the present invention includes the following steps: a) Divide the pipe rotation angle into multiple independent calculation intervals at preset intervals, and set the initial proportional relationship between the axial movement speed and the radial feed amount in each interval; b) Real-time collect the actual radial displacement data of the cutting machine, and compare it with the theoretical calculation value of the current interval. If the deviation exceeds the set threshold, dynamically adjust the proportional relationship to generate corrected parameters after compensation; c) When switching between adjacent intervals, extract the rotational speed change trend data of the servo motor, and dynamically adjust the correction amplitude of the radial feed amount according to the preset weight coefficient in combination with the current axial movement speed; d) If the angle deviation in multiple consecutive intervals continuously exceeds the tolerance range, switch to the prediction correction mode, and perform path calculation based on the average proportional parameters of the historical processing intervals until the deviation returns to the allowable range; e) Convert the corrected proportional parameters into pulse control signals, and control the axial speed and radial feed action of the cutting machine moving mechanism by adjusting the pulse duty cycle.

[0025] Preferably, the implementation of the motion correlation model of the present invention includes the following steps: Real-time collect the pipe rotation angle data of the servo motor encoder and the radial displacement data of the cutting machine displacement sensor, calculate the change rate of the displacement reading. If the change rate exceeds the preset threshold within three consecutive sampling periods, it is determined as the abnormal trigger state of the roundness; In the abnormal trigger state, extract the theoretical radial displacement value corresponding to the current pipe rotation angle, and perform differential calculation with the actual displacement value to generate the primary compensation amount of the radial feed rate; According to the rotational acceleration trend of the encoder in the recent five angle intervals, predict the pipe deformation trend in the next interval, and superimpose to generate the secondary dynamic compensation amount of the feed rate; Fuse the primary compensation amount and the secondary dynamic compensation amount according to the preset weight, and output it to the servo driver of the cutting machine moving mechanism to control the feed rate to be adjusted step by step in an increasing or decreasing manner; If the displacement sensor reading returns to the normal threshold range within two consecutive pipe rotation periods, gradually cancel the compensation amount and switch to the standard control mode.

[0026] Beneficial effects: Through the closed-loop pressure regulation of the clamping mechanism and the precise control of the servo motor, the clamping stability is significantly improved, and the probability of pipe sliding caused by the clamping force fluctuation is reduced by more than 70%; The path correction algorithm combines angle data and displacement feedback to control the cutting trajectory deviation within ±0.2 mm, which is suitable for high-precision pipe prefabrication.

[0027] The coaxial centering design of the double chucks ensures uniform distribution of the clamping force. The pressure sensor is embedded inside to monitor the local pressure change in real time, reducing the risk of pipe deformation and increasing the roundness adaptability by 50%.

[0028] The dynamic compensation algorithm establishes a linear correlation model between the clamping force and the rotation angle, and the compensation coefficient adjusts the axial speed of the cutting machine in real time, reducing the influence of clamping fluctuations on the trajectory by 60% and significantly enhancing the processing continuity.

[0029] The dynamic frequency modulation unit works in coordination with the start-stop safety interlock logic. When overloaded or with position deviation, the response time is shortened to within 0.5 seconds, the equipment failure rate is reduced by 45%, and at the same time, the pulse overload protection mode avoids the risk of motor burnout.

[0030] The three-level pressure fluctuation response mechanism controls the servo speed and cutting action according to the fluctuation level. The processing efficiency remains 90% under mild fluctuations, and the emergency stop response speed increases by 30% in case of severe abnormalities, greatly improving the safety.

[0031] The data segmented processing module shortens the path correction calculation period to the millisecond level, reduces the cumulative error of the high-speed rotating pipeline to ±0.15 mm, and at the same time, the angle compensation logic suppresses the trajectory oscillation caused by sudden acceleration changes.

[0032] The dynamically updated pressure threshold is automatically calibrated based on historical processing data, reducing the false triggering rate by 60%. The buffer pause program maintains the axial position error within ±0.15 mm, and the recovery efficiency after processing interruption is increased by 40%.

[0033] The angle segmented calculation mechanism combines with the real-time verification link, improving the compensation accuracy of the local deformation of the elliptical pipeline to ±0.1 mm. The differential correction amount introduces the rotational speed acceleration parameter, reducing the overshoot phenomenon by 50%.

[0034] The segmented verification and prediction mode switching mechanism shortens the correction response time to 50 ms under abnormal conditions, improves the path deviation recovery efficiency by 55%, and reduces the processing scrap rate to less than 3%.

[0035] The ellipticity compensation model with multi-source data fusion distinguishes normal fluctuations from abnormal deformations, and the primary and secondary compensation amounts jointly adjust the feed rate. The cutting efficiency of the elliptical pipeline is increased by 35%, and the Ra value of the cut surface roughness is stabilized within 6.3 μm. Brief Description of the Drawings

[0036] Figure 1 It is a structural schematic diagram of the cutting equipment for pipeline prefabrication processing described in the present invention.

[0037] Reference Signs: 1 - Frame; 2 - Pipeline conveying device; 3 - Clamping mechanism; 4 - Cutting execution mechanism; 5 - Driving device of the cutting mechanism. Detailed Description of the Embodiment

[0038] The following further elaborates on the present invention in conjunction with the drawings, so that those skilled in the art can implement it with reference to the description in the specification.

[0039] According to an embodiment of the present invention, an existing cutting equipment hardware for pipe prefabrication processing is adopted, such as that disclosed in a paper with the title "Design and implementation of pipe cutting machine with AC servo motor and PLC based on HMI"; author: S Syufrijal, M Rif'an, A W R Prabumenang, RWicaksono; author's affiliation: Electronics Technology Diploma, Faculty of Engineering, Universitas Negeri Jakarta, Jl. Rawamangun Muka, Jakarta 13220, Indonesia; journal name: IOP Conference Series: Materials Science and Engineering; volume number: 1098; publication year: 2021, as follows Figure 1 as shown

[0040] This kind of cutting equipment hardware for pipe prefabrication processing includes a frame 1, which is the main support structure and bears all functional modules; it is made of high-strength steel and its surface has been rust-proof treated; it can include a workbench, guide rails and mounting bases.

[0041] It also includes a pipe conveying device 2, which is used to convey the pipe to be cut to the processing position and can include a roller conveyor belt or a chain conveying mechanism; it is docked with the clamping mechanism 3 to ensure the accurate positioning of the pipe.

[0042] It also includes a clamping mechanism 3, two sets of coaxially arranged chucks, and pressure sensors are embedded inside each chuck. For example, a hole groove can be opened on the pressure rod of the chuck, and a pressure sensor is placed inside. An adjustable-spacing mounting seat is used to adapt to pipes of different lengths. A servo motor (with an absolute encoder) is rigidly connected to the main shaft of the pressure rod on the chuck through a coupling to drive the pressure rod to rotate and realize the conversion between clamping and non-clamping.

[0043] It also includes a cutting execution mechanism 4, including a cutting machine: a disc-type cutting tool (such as a plasma cutting head or a grinding wheel), which can move radially along the pipe; a moving mechanism: a ball screw or a linear guide rail system driven by a servo motor, and a displacement sensor can be equipped (the detection direction is the same as the movement direction of the cutting machine); a driving device 5 of the cutting mechanism: includes a servo motor to control the axial movement speed and radial feed amount of the cutting machine.

[0044] It also includes a control module: including a PLC controller: integrating synchronous control logic, dynamic compensation algorithms, and path correction algorithms. A human-machine interface (HMI): a touch screen that displays the clamping force curve, rotation angle coordinates, and cutting trajectory in real time. A sensor interface: connecting pressure sensors, displacement sensors, and servo motor encoders.

[0045] Assembly method: Integration of the frame and the pipe conveying device: The pipe conveying device 2 is fixed at the front end of the frame 1 and is coaxially aligned with the clamping mechanism 3 to ensure that the pipe smoothly enters the processing area; Installation of the clamping mechanism: Two groups of chucks are fixed on the workbench of the frame through an adjustable-spacing mounting seat, and the pressure sensors on the inner sides of the chucks are in direct contact with the pipe surface; The servo motor is rigidly connected to the rotating spindle of one group of chucks through a coupling to drive the pipe to rotate at a constant speed; Assembly of the cutting execution mechanism: The cutting machine 4 is installed on the moving mechanism and is arranged along the radial guide rail, and the displacement sensor is fixed on the side of the moving mechanism; The driving device 5 of the cutting mechanism is connected to the ball screw through a servo motor to control the forward / backward (up and down) movement of the cutting machine; Integration of the control module: The PLC controller is installed in the electrical cabinet on the side of the frame and is connected to the servo motor, sensors, and HMI through cables; The HMI is embedded in the operation panel of the frame to provide real-time monitoring and parameter setting functions.

[0046] Working method: Pipe positioning and clamping: The pipe enters the processing area through the conveying device 2 and is clamped by two groups of chucks of the clamping mechanism 3; The pressure sensor monitors the clamping force in real time. If the fluctuation exceeds the limit, the PLC triggers closed-loop regulation (such as starting the hydraulic pump to supplement pressure); Servo drive and pipe rotation: The servo motor drives the chuck to rotate, driving the pipe to rotate at a constant speed according to the set speed; The absolute encoder feeds back the pipe rotation angle data in real time for the path correction algorithm to calculate the cutting trajectory; Cutting execution and dynamic correction: The cutting machine 4 moves radially according to the PLC instruction, and the displacement sensor feeds back the actual position in real time; The path correction algorithm combines the encoder angle data and the displacement feedback to dynamically adjust the ratio of the axial speed and the radial feed of the cutting machine to compensate for the deviation caused by ellipticity or clamping force fluctuation; Abnormal response and safety protection: If the clamping force continues to exceed the limit, the PLC responds according to three-level thresholds: reducing speed, pausing to buffer, and emergency stop; When the cutting machine pauses, the servo motor executes an angle retraction (5°) and maintains the plasma arc for 0.5 seconds to protect the cutting head; Human-machine interaction and data recording: The HMI displays the clamping force curve, rotation angle, and cutting trajectory in real time, and the operator can adjust the parameters at any time; Data such as the peak clamping force and the number of path corrections for each processing are automatically stored for quality traceability.

[0047] According to another embodiment of the present invention, the clamping force is ensured to be evenly distributed through a double-chuck coaxial design, reducing pipe deformation; multi-level dynamic compensation: millisecond-level error correction is achieved through segmented calculation and prediction mode switching; safety interlock mechanism: the cutting instruction is automatically locked when the position deviation exceeds the limit, avoiding equipment damage; adaptive pressure threshold: dynamically updated based on historical data, reducing the false triggering rate; through high-precision sensing, real-time algorithms and multi-mechanism cooperation, the device significantly improves the accuracy and stability of pipe cutting, especially suitable for elliptical pipes or high-speed rotating working conditions.

[0048] The upper limit of the set range for the clamping force detected by the pressure sensor can be set to 10 kN, and the hydraulic pump pressure compensation program is triggered when the deviation continuously exceeds for 5 seconds. The adjustment range of the chuck spacing can be set to 200 - 800 mm to adapt to pipes of different lengths. The pressure sensor can be a piezoresistive sensor with a range of 0 - 15 kN and a response time of 1 ms, installed on the contact surface of the clamping jaw inside the chuck. The chuck can be a three-jaw self-centering structure made of high-strength alloy steel 42CrMo, and the surface is nitrided to improve wear resistance. The two groups of chucks are fixed on the guide rail of the frame workbench 1 through an adjustable-spacing mounting seat. The adjustment bolt of the mounting seat uses trapezoidal threads with a pitch of 5 mm for easy manual fine-tuning. After the pipe is transported to the processing area, the chucks clamp the pipe synchronously through hydraulic drive, and the pressure sensor monitors the clamping force value in real time; when the detected value deviates from the set range by ±5%, the PLC controller triggers the hydraulic pump pressure compensation program, and adjusts the oil pressure through a proportional valve until the pressure stabilizes within the tolerance band.

[0049] The rated speed of the servo motor can be set to 3000 rpm, the encoder resolution is 17 bits, and the angle feedback accuracy is ±0.01°. When the pressure sensor detects that the clamping force fluctuation exceeds 10% of the set upper limit, the speed of the servo motor linearly decreases to the preset safety value of 2400 rpm, and the deceleration gradient is to reduce 5% of the current speed per second. The servo motor can be an AC servo motor, rigidly connected to the rotating main shaft of the chuck 3 through an elastic coupling. The rated torque of the coupling is 50 N·m, allowing an axial deviation of ±0.1 mm. The PLC controller can be a modular structure, supporting 4-channel analog input channels of ±10 V and 2-channel pulse output frequency range of 0 - 100 kHz, installed in the electrical cabinet on the side of the frame 1, and connected to the sensor and the driver through a shielded cable. When the servo motor drives the chuck to drive the pipe to rotate at a constant speed, the encoder feeds back the angle data to the PLC every 0.1 ms; if the clamping force fluctuation continuously exceeds 15% of the upper limit for 2 seconds, the PLC sends an emergency stop instruction, simultaneously cuts off the enable signal of the servo motor, and triggers the buffer pause program of the cutting machine.

[0050] The measuring range of the displacement sensor can be set to 0 - 100 mm, the accuracy is ±0.02 mm, the sampling frequency is 1 kHz, and it is installed on the side of the moving mechanism of the cutting machine. The radial feed rate of the cutting machine can be set to 0.1 - 1.5 m / min. The axial moving mechanism uses a ball screw drive with a lead of 10 mm and a repeat positioning accuracy of ±0.01 mm. The disc-type cutting machine can be equipped with a plasma cutting head with a rated current of 40 A, a cutting thickness range of 1 - 20 mm, and a nozzle diameter of 1.2 mm. The displacement sensor can be a magnetic grating ruler, and the detection direction is parallel to the radial movement direction of the cutting machine. It is fixed to the base of the moving mechanism by bolts. When the cutting machine 4 feeds radially according to the PLC command, the displacement sensor real-time collects the actual position data; the path correction algorithm divides the pipeline rotation angle fed back by the encoder into intervals of every 30°, and calculates the proportional relationship between the axial speed and the radial feed amount within each interval. If the deviation between the actual displacement and the theoretical value exceeds 3% of the axial speed, the algorithm automatically generates a reverse correction command and adjusts the feed rate of the cutting machine through pulse width modulation.

[0051] Technical effects: The closed-loop pressure regulation of the clamping mechanism and the double chuck design improve the clamping stability and reduce the risk of pipeline sliding; the dynamic cooperative control of the servo motor and the PLC realizes the high-precision compensation of the cutting trajectory; the displacement sensor and the segmented path correction algorithm effectively suppress the cutting deviation caused by the elliptical pipeline and improve the processing quality; the multi-level safety response mechanism shortens the downtime in abnormal states and ensures the reliable operation of the equipment.

[0052] According to another embodiment of the present invention, the clamping mechanism includes two groups of chucks arranged coaxially. The two groups of chucks are fixed on the machine frame workbench (reference numeral 1) through an adjustable-spacing mounting seat. The spacing adjustment range of the chucks can be set to 200 - 800 mm to adapt to the processing requirements of pipelines of different lengths. A pressure sensor is embedded inside each group of chucks. The installation position of the sensor can be located in the central area of the chuck clamping surface, and the detection direction is perpendicular to the pipeline surface. The chuck can be a three-jaw self-centering hydraulic chuck, and the clamping jaw material can be selected as hard alloy steel to improve wear resistance. The mounting seat can be an HT250 gray cast iron base with a T-slot, and is fixed to the guide rail of the workbench by bolts to ensure the stability of the chuck during the adjustment process. The pressure sensor can be a piezoelectric sensor with a stainless steel housing, which is embedded in the inner groove of the chuck clamping jaw. After the pipeline is sent into the clamping mechanism by the conveying device, the two groups of chucks are synchronously closed and clamped by hydraulic drive, and the pressure sensor monitors the clamping force in real time. When the detected value deviates from the set range, the closed-loop adjustment program is triggered.

[0053] The driving motor uses a servo motor with an absolute encoder. The output shaft of the servo motor is rigidly connected to the rotating spindle of at least one set of chucks through a coupling. The rated power of the servo motor can be set to 3 - 7.5 kW, and the torque capacity of the coupling can be selected from 50 - 200 N·m to adapt to the load requirements of different pipe diameters. The coupling can be a plum blossom type elastic coupling, and the elastomer material is polyurethane to buffer the vibration during transmission. The servo motor housing can be made of aluminum alloy and is fixed on the motor bracket on the side of the frame through a flange. The absolute encoder can be an optoelectronic encoder with a 17-bit resolution, and the housing material is engineering plastic, which is installed coaxially with the servo motor. The servo motor drives the rotating spindle of the chuck to drive the pipe to rotate uniformly, and the encoder real-time feeds back the rotation angle data to the PLC controller for synchronous control of the cutting trajectory. When the rotation angle of the pipe deviates from the preset path, the encoder data adjusts the speed of the servo motor through a closed-loop link.

[0054] The cutting execution mechanism includes a disc-type cutting machine that can move radially along the pipe, and a displacement sensor is installed on the moving mechanism of the cutting machine. The radial moving stroke of the cutting machine can be set to 0 - 150 mm, the detection accuracy of the displacement sensor is ±0.01 mm, and the detection direction is parallel to the moving guide rail of the cutting machine. The disc-type cutting machine can be a plasma cutting head or a diamond grinding wheel, and the cutter head material can be high-speed steel to extend the service life. The moving mechanism can be driven by a ball screw, the screw material is chromium molybdenum alloy steel, and the surface of the guide rail is hardened to reduce friction loss. The displacement sensor can be a magnetic scale or a laser displacement sensor, and the scale material is stainless steel, which is fixed on the side of the sliding table of the moving mechanism. The cutting machine moves radially along the guide rail according to the PLC instruction, and the displacement sensor real-time feeds back the actual position data. When the pipe ovality causes the cutting path to deviate, the PLC combines the encoder angle data with the displacement feedback to dynamically adjust the feed rate of the moving mechanism to ensure that the cutting trajectory accuracy is controlled within ±0.2 mm.

[0055] Technical effects: Through the above implementation methods, the double-chuck design of the clamping mechanism can adapt to pipes of different lengths. The pressure sensor monitors the clamping force fluctuation in real time to reduce the risk of pipe deformation. The cooperation between the servo motor and the absolute encoder realizes high-precision control of the rotation angle to ensure that the cutting path is consistent with the preset trajectory. The displacement sensor and the dynamic adjustment mechanism of the cutting execution mechanism effectively compensate for the ovality deviation and improve the cutting quality. The overall structure takes into account both stability and adaptability to meet the requirements of high-precision pipe prefabrication.

[0056] According to another embodiment of the present invention, the PLC controller is built-in with a dynamic compensation algorithm, which establishes a linear correlation model between the real-time clamping force fluctuation value detected by the pressure sensor and the pipeline rotation angle data fed back by the servo motor encoder. The sampling frequency of the clamping force fluctuation value can be set to 100 Hz, and the angle data resolution of the encoder can be selected as 17 bits. The slope coefficient of the linear correlation model can be set to 0.05 - 0.2, and the intercept range can be adjusted to ±5 N. The PLC controller can be an industrial-grade modular controller, supporting analog input and pulse output. The signal of the pressure sensor is connected to the PLC through the analog input port, and the data of the servo motor encoder is transmitted through the high-speed communication interface. The output compensation coefficient of the linear correlation model can be adjusted in steps of 0.01 and sent to the servo driver of the cutting machine moving mechanism through the digital output port. The operation cycle of the PLC controller can be set to 1 ms to ensure real-time performance. During assembly, the PLC controller (not clearly marked with reference numerals) is installed in the electrical cabinet on the side of the rack and is connected to the pressure sensor and the encoder through shielded cables. During the working process, when the clamping force fluctuation value exceeds the set threshold (such as ±10 N), the algorithm calculates the compensation coefficient according to the current rotation angle and dynamically adjusts the axial movement speed of the cutting machine.

[0057] The human-machine interface is provided with a data synchronization display unit, which parallelly displays the clamping force fluctuation curve, the real-time speed value of the servo motor, and the trajectory model of the cutting machine displacement trajectory on the touch screen interface. The size of the touch screen can be selected as 10.1 inches, with a resolution of 1280×800. The refresh frequency of the clamping force fluctuation curve can be set to 50 Hz, and the display accuracy of the servo motor speed value is ±1 rpm. The coordinate system of the trajectory model can be scaled at a ratio of 1:10, and the proportional relationship between the axial movement speed and the radial feed amount is presented in a dynamic line graph. The touch screen can be an industrial-grade capacitive screen with an IP65 protection level. The software of the data synchronization display unit can be developed based on a configuration tool, supporting multi-threaded data processing. The touch screen communicates with the PLC controller through the Ethernet interface and is installed in the central position of the rack operation panel (not clearly marked with reference numerals). During the working process, the operator can monitor the clamping force fluctuation range, the change trend of the servo motor speed, and the real-time deviation of the cutting machine displacement trajectory in real time through the touch screen, and manually fine-tune the processing parameters according to the displayed data.

[0058] When the dynamic compensation algorithm detects that the clamping force fluctuation exceeds the set threshold (e.g., ±15 N), it generates a segmented decreasing instruction sequence for the radial feed of the cutting machine according to the current servo motor speed. The gradient of the segmented decrease can be set to reduce the feed by 5% every 0.5 seconds, and the maximum decrease amplitude does not exceed 50% of the initial value. The speed closed-loop control link of the servo motor driver adopts a proportional-integral (PI) algorithm, with the proportional coefficient set to 0.8 and the integral time constant to 0.1 seconds. A closed-loop control is established between the PLC controller and the servo motor driver through the pulse output port and the encoder feedback link. The overload protection threshold of the servo driver can be set to 120% of the rated current, and the response time is 10 ms. During assembly, the servo motor driver is installed in the electrical cabinet and connected to the PLC controller through a shielded cable. During operation, when the displacement sensor detects that the deviation between the actual displacement and the calculated path exceeds ±0.3 mm, the PLC controller reversely adjusts the angular acceleration compensation value of the servo motor, and the compensation amount can be calculated as 0.5 times the deviation. The feed rate of the cutting machine moving mechanism is dynamically adjusted according to the compensation coefficient to ensure that the trajectory deviation gradually converges.

[0059] Technical effects: Through the linear model and compensation coefficient output of the dynamic compensation algorithm, the influence of clamping force fluctuation on the cutting path is corrected in real time. The data synchronization display unit of the human-machine interface provides intuitive monitoring of the processing status, facilitating timely intervention by the operator. The segmented decreasing instruction and the speed closed-loop control link work together to smoothly adjust the equipment operation parameters in abnormal states and reduce mechanical impact. The overall design improves the stability of the cutting trajectory and the controllability of the processing process, and is applicable to high-precision pipe processing scenarios.

[0060] According to another embodiment of the present invention, the adjustment range of the pulse frequency can be set to 70%-130% of the reference frequency corresponding to the rated speed of the servo motor. For example, when the reference frequency is 10 kHz, the actual output frequency can be adjusted to 7-13 kHz. The dynamic frequency modulation unit can adjust the pulse frequency according to the clamping force data detected by the pressure sensor in real time. For example, when the clamping force fluctuation exceeds the set value of ±8%, the pulse frequency is adjusted at a gradient of increasing or decreasing by 5% every 0.5 seconds. The servo motor driver can select a model that supports dynamic modulation of the pulse frequency, with an input voltage range of 24 V DC and a maximum output current of 5 A. An optoelectronic isolation circuit can be set between the pulse output port of the PLC controller and the servo motor driver to prevent electromagnetic interference. This unit establishes a closed-loop feedback link with the servo motor encoder through a shielded cable, and the actual speed data fed back by the encoder is processed by the proportional-integral algorithm to generate a compensation increment of the pulse frequency. For example, for every 1 rpm increase in the speed error, the pulse frequency is compensated by 0.1%.

[0061] In the start / stop safety interlock logic of the digital output port, the threshold for the initial position deviation of the cutting machine's moving mechanism from the set origin can be set to 1 mm. When the displacement sensor detects a deviation exceeding this threshold, the PLC controller automatically locks the cutting machine's start command and triggers the touchscreen prompt "Position calibration incomplete." The position calibration procedure can be completed by manually fine-tuning the moving mechanism's ball screw, which has a lead of 5 mm and a repeatability of ±0.005 mm. The cutting machine's moving mechanism's origin sensor can be a proximity switch with a detection distance of 2 mm, mounted at the end of the moving mechanism's guide rail. During the calibration process, the operator manually controls the cutting machine's movement to the mechanical origin through the human-machine interface (HMI). The displacement sensor provides real-time position data until the deviation is less than 0.1 mm and the lock is released.

[0062] In the delayed trigger mechanism of the start-stop safety interlock logic, the plasma arc maintenance time can be set to 0.5 seconds, and the servo motor angle retraction can be set to 5°. Upon receiving the cutting machine stop command, the PLC controller maintains the plasma arc power supply for 0.5 seconds before shutting off. Simultaneously, it sends a pulse signal to the servo motor to retract 5°. The servo motor's retraction action uses an absolute encoder to provide angle data, and the retraction speed is set to 20% of the rated speed. In the overload protection mode of the pulse output port, the current detection threshold can be set to 120% of the rated current. For example, for a rated current of 10 A, the trigger threshold is 12A. If the current detection value exceeds the threshold for three consecutive seconds, the pulse frequency automatically decreases to 50% of the base frequency, for example, from 10 kHz to 5 kHz, triggering a pop-up alert on the touchscreen indicating "Motor Overload." The overload protection circuit can utilize a resettable fuse with a rated current of 15 A and a response time of less than 0.1 second.

[0063] Technical Effects: 1. The dynamic frequency modulation unit achieves precise pulse frequency adjustment through closed-loop feedback, improving the stability of servo motor speed control. 2. The start-stop safety interlock logic and position calibration mechanism effectively prevent malfunction of the cutting machine due to position deviation, ensuring processing safety. 3. The delayed trigger mechanism reduces damage to the cutting head caused by the sudden severance of the plasma arc, and the motor retraction action prevents the adhesion of processing residues. 4. The overload protection mode promptly limits the pulse frequency and issues an alarm, reducing the risk of damage to the servo motor due to abnormal current.

[0064] According to another embodiment of the present invention, the synchronization control logic includes a multi-level response mechanism. When the pressure sensor detects that the clamping force fluctuation value exceeds 10% of the upper limit of the set range, the rotational speed of the servo motor is linearly reduced to 80% of the preset safety value. At the same time, a cutter pause preparation signal is sent to the digital output port. The threshold value of the upper limit of the set range can be specified as ±15% of the rated clamping force. For example, when the rated clamping force is 500N, the first-level threshold value is 550N or 450N. The linear reduction gradient of the rotational speed of the servo motor can be set to 2% reduction every 0.5 seconds. The rotational speed range corresponding to 80% of the preset safety value is, for example, reduced from 300 rpm to 240 rpm. The servo motor driver can be selected as a model that supports multi-speed control. The sampling frequency of the analog input module of the PLC controller can be set to 100 Hz. The signal of the pressure sensor is connected to the PLC controller through a shielded cable and is installed in the electrical cabinet of the frame. When the clamping force fluctuation value exceeds the first-level threshold value, the PLC controller adjusts the pulse frequency of the servo motor through the pulse output port, gradually reduces the rotational speed, and sends a pause preparation signal to the cutter to prompt the operator to check the clamping state.

[0065] When the clamping force fluctuation value continuously exceeds 15% of the upper limit of the set range for 2 seconds, the rotational speed of the servo motor is forcibly switched to 50% of the preset safety value, and an emergency stop instruction for the cutter is sent through the digital output port. The duration determination of the second-level threshold value can be based on the timer module of the PLC, and the time error is controlled within ±0.1 second. 50% of the preset safety value of the servo motor is, for example, reduced from 300 rpm to 150 rpm. The emergency stop instruction is output to the cutter power control circuit through the relay contact. The emergency stop response time of the cutter can be set within 0.2 seconds, and the braking resistor of the servo motor driver can be selected as the aluminum alloy shell type. After the emergency stop instruction is triggered, the moving mechanism of the cutter immediately stops feeding, and the servo motor enters the free parking mode. The PLC controller is installed in the electrical cabinet on the side of the frame, and the emergency stop signal line is connected to the cutter drive device through an independent safety circuit. During the working process, if the clamping force fluctuation does not return below the threshold value within 2 seconds, the PLC forcibly cuts off the enable signal of the servo motor and triggers the emergency stop instruction to avoid equipment overload or pipeline damage.

[0066] The calculation of the preset safety value is based on the average rotational speed of the servo motor encoder recorded in the most recent 10 processing cycles, and a dynamic rotational speed threshold is generated through conversion using the reference frequency of the pulse output port. The data storage period of the encoder can be set to be automatically updated at the end of each processing cycle. The average rotational speed calculation uses a sliding window algorithm with a window length of 10 cycles. The reference frequency conversion can be implemented according to the formula "frequency = rotational speed × number of encoder lines / 60". For example, when the number of encoder lines is 2048, 300 rpm corresponds to a frequency of 10.24 kHz. The arithmetic memory of the PLC controller can be configured to support floating-point operations to ensure that the accuracy error of the dynamic threshold is less than ±0.5%. The encoder is fixed to the tail of the servo motor through a flange, and the data is transmitted to the PLC through a high-speed communication interface. Before the start of each processing task, the PLC automatically reads the historical rotational speed data of the encoder, calculates the dynamic rotational speed threshold, and updates it to the control logic. If the clamping force fluctuation value returns to the set range within 5 seconds after an emergency stop, the PLC restarts the servo motor at 85% of the original rotational speed, for example, adjusting from 300 rpm to 255 rpm, and gradually resumes the cutting machine operation.

[0067] Technical effects: The multi-level pressure fluctuation determination threshold can respond in stages according to the clamping state, maintaining the processing efficiency during mild fluctuations and quickly protecting the equipment during severe abnormalities. The calculation of the dynamic rotational speed threshold is based on historical processing data, improving the adaptability to different working conditions. The combination of the emergency stop and recovery mechanism reduces unnecessary interruption time, ensuring the safety and continuity of the processing process. The overall design enhances the robustness to clamping force fluctuations and is suitable for the stable processing requirements of high-precision pipelines.

[0068] According to another embodiment of the present invention, the pipe rotation angle can be divided into independent calculation intervals every 15°, and the slope parameter of the radial feed amount is dynamically corrected according to the cumulative value of the axial movement speed within each interval. When the deviation between the actual radial feed amount and the theoretically calculated value exceeds 5% of the axial movement speed, for example, the deviation exceeds 0.025 m / s when the axial speed is 0.5 m / s, an instruction to recalculate the slope parameter of the current interval is automatically triggered. The data segmentation processing module can be integrated in the PLC controller and uses a 32-bit floating-point arithmetic unit with a calculation period of 1 ms. The displacement sensor can be a magnetic grating ruler with a measuring range of 0 - 200 mm and an accuracy of ±0.01 mm, installed on the side of the cutting machine moving mechanism, and the detection direction is parallel to the radial movement direction of the cutting machine. At the end of each interval, the PLC controller extracts the radial feed amount correction data of the most recent three intervals to generate a prediction reference value for the axial movement speed in the next cycle, for example, calculating the prediction value based on the moving average method.

[0069] The calculation result of the proportional relationship is converted into a control signal for the cutting machine's moving mechanism through pulse width modulation. For every 0.1 m / s change in the axial moving speed, the corresponding pulse duty cycle adjustment range can be set to 0.8% - 1.2%. For example, when the speed increases from 0.5 m / s to 0.6 m / s, the duty cycle is adjusted from 50% to 50.8%. The pulse modulation module can select a PWM controller with an output frequency of 20 kHz and a duty cycle resolution of 0.1%. The servo driver can select a model that supports the pulse direction interface, with an input signal voltage of 5 V TTL and a maximum response frequency of 200 kHz. The lead of the ball screw of the cutting machine's moving mechanism can be set to 10 mm, made of GCr1 bearing steel, with a surface hardness of HRC58 - 62, and installed on the radial guide rail of the frame (1). When the moving mechanism adjusts the feed rate according to the pulse signal, the displacement sensor real-time feedbacks the actual position and performs a closed-loop comparison with the theoretical value.

[0070] When the change rate of the rotational angle acceleration in two consecutive calculation intervals is detected to exceed 0.5 rad / s², for example, when the acceleration suddenly increases from 0.2 rad / s² to 0.8 rad / s², the slope parameter of the radial feed amount is forced to be locked to the moving average of the previous three intervals. The angle compensation logic can be embedded in the dynamic compensation algorithm of the PLC controller, and the sliding window method is used to calculate the mean value of historical data, with the window length being 3 intervals. The servo motor encoder can select a multi-turn absolute type with a resolution of 17 bits, installed at the end of the motor output shaft, and connected to the chuck spindle through a coupling. In the abnormal locking state, the PLC controller continuously monitors the angle change rate. If the data in the subsequent intervals returns within the threshold, the lock is automatically released and switched back to the dynamic correction mode. The data of the displacement sensor and the encoder are transmitted to the PLC through the CAN bus, and the transmission cycle is 0.5 ms.

[0071] Technical effects: 1. The data segmentation processing and feedback verification mechanism shorten the path correction response time and reduce the accumulation of local deviations. 2. Pulse width modulation realizes fine control of the axial speed and improves the smoothness of the cutting trajectory. 3. The angle compensation logic suppresses the trajectory oscillation caused by sudden acceleration changes and enhances the stability of the processing process. 4. The abnormal locking mechanism avoids incorrect corrections caused by sensor noise or instantaneous interference and improves the system reliability.

[0072] According to another embodiment of the present invention, the synchronous control logic sets a three - level pressure fluctuation determination threshold. The first - level threshold is 8% of the upper limit of the set range, triggering the servo - motor speed to decrease at a gradient of 2% every 0.5 seconds, and at the same time sending a preparation pause signal to the cutting machine. The value of the upper limit of the set range can be based on the rated clamping force. For example, when the rated clamping force is 600N, the first - level threshold is 648N or 552N. The adjustment of the speed gradient of the servo - motor can be achieved through the pulse output port of the PLC controller, and the pulse - frequency adjustment step can be set to 0.1kHz. The second - level threshold is 12% of the upper limit of the set range. For example, when the rated clamping force is 600N, it corresponds to 672N or 528N. When the fluctuation value continuously exceeds this threshold for 2 seconds, the servo - motor speed is forcibly locked at 60% of the current value. The third - level threshold is 20% of the upper limit of the set range (for example, 720N or 480N), triggering the immediate cut - off of the servo - motor enable signal and switching the cutting - machine power supply to the standby mode. The pressure sensor can be a piezoresistive sensor, and the signal is connected to the PLC controller through the analog - input module and installed inside the chuck clamping jaws. When the clamping - force fluctuation exceeds the first - level threshold, the PLC gradually reduces the servo - motor speed, and at the same time activates the cutting - machine pause preparation state. The operator can view the alarm information through the human - machine interface (HMI).

[0073] During the execution of the buffer pause program, the real - time position data of the displacement sensor is read synchronously, and the position error of the axial movement mechanism is maintained within ±0.15mm during the cutting - machine pause. The detection accuracy of the displacement sensor can be set to ±0.01mm, and the sampling frequency is 200Hz. The duration of the buffer pause can be set to 0.3 seconds. During this period, the servo - motor performs a 5° angle backward movement, and the backward speed can be set to 10rpm. The displacement sensor can be a magnetic scale, the scale is made of stainless steel, and is installed on the side of the slide of the cutting - machine movement mechanism. The PLC controller receives the displacement data through the high - speed communication interface and compares it with the preset path in real - time. If the position deviation exceeds ±0.15mm, the PLC triggers a fine - tuning instruction to adjust the feed of the ball screw through the servo - motor driver to gradually correct the deviation. During the buffer pause, the plasma arc of the cutting machine is cut off after 0.5 seconds to avoid damage to the cutting head due to sudden stop.

[0074] The value of the three - level pressure fluctuation determination threshold is dynamically updated according to the standard deviation of the clamping force in the last 5 normal processing cycles recorded by the servo - motor encoder. The update period is automatically calibrated before each processing task starts. The sampling window for the standard deviation of the clamping force can be set to the last 5 processing tasks, with each task lasting 10 - 30 minutes. The calibration algorithm can be based on the moving - average method, with a standard - deviation calculation period of 1 second and an allowable deviation range of ±3% when updating the threshold. The servo - motor encoder can be a multi - turn absolute - type with a resolution of 17 bits, fixed to the motor tail through a flange. When each processing task starts, the PLC automatically reads the historical clamping - force data, calculates the standard deviation, and updates the three - level threshold. For example, if the historical standard deviation is 20N, the first - level threshold is updated to the current set value ±(20N×8%). The encoder data is transmitted to the PLC through a high - speed bus to ensure real - time calibration. The dynamic update mechanism avoids threshold failure caused by equipment wear or environmental changes and improves the system's adaptability.

[0075] According to another embodiment of the present invention, the pipe rotation angle can be divided into independent calculation intervals every 30°. The differential correction amount of the radial feed is dynamically calculated according to the real - time value of the axial movement speed within each interval. For example, when the axial speed is 0.6 m / s, the differential correction amount can generate a dynamic adjustment factor by multiplying the rotational acceleration value (such as 0.3 rad / s²) by the current axial speed. The servo - motor encoder can be a multi - turn absolute - type with a resolution of 17 bits, installed at the motor output - shaft end, and rigidly connected to the chuck spindle through a coupling. The PLC controller can be a model that supports floating - point operations, with a calculation period of 1 ms and an internal data - segmentation processing module. The angle data fed back by the encoder is transmitted to the PLC through the CAN bus, with a transmission period of 0.5 ms. At the end of each calculation interval, the PLC differentially compares the actual radial displacement detected by the displacement sensor with the theoretical value. If the cumulative deviation exceeds 3% of the axial movement speed (for example, when the axial speed is 0.5 m / s, the deviation exceeds 0.015 m / s), it automatically generates a reverse - correction instruction for the compensation coefficient of the next interval.

[0076] The path correction algorithm and the displacement sensor can establish a real-time calibration link. After the axial movement mechanism completes a 2 mm stroke each time, a position calibration operation for the radial feed amount is forcibly triggered. The displacement sensor can be a grating scale with a measuring range of 0 - 150 mm and an accuracy of ±0.005 mm. It is installed on the side of the cutting machine's movement mechanism, and the detection direction is parallel to the radial feed direction. During the calibration process, the PLC controller reads the actual position data of the grating scale and compares it with the theoretical value; if the deviation exceeds ±0.02 mm, the feed rate of the servo drive is adjusted through a pulse signal. The lead of the ball screw can be set to 5 mm, the material is GCr15 bearing steel, the surface hardness is HRC60, and it is installed on the radial guide rail of the frame 1. The servo motor of the movement mechanism can be a stepper motor with a step angle of 1.8° and a drive voltage of 24 V DC. It is connected to the ball screw through a synchronous belt.

[0077] When the deviation of the pipeline rotation angle increment in three consecutive calculation intervals exceeds 5°, for example, the theoretical angle value is 90° while the actual detected value is 95°, the system automatically switches to the prediction calculation mode based on the average angular velocity of the previous five intervals. In the prediction calculation mode, the PLC controller extracts the historical angle data and uses the moving average method to generate the predicted angular velocity for the next interval. For example, the average value of the previous five intervals is taken as the reference. The installation position of the servo motor encoder needs to be coaxial with the chuck spindle, and the allowable radial deviation of the coupling does not exceed ±0.05 mm. The abnormal data processing logic can be embedded in the dynamic compensation algorithm of the PLC, and a threshold comparison mechanism is adopted. When the angle deviation exceeds 5° three times in a row, the mode switch is triggered. The guide rail of the cutting machine's movement mechanism can be made of aluminum alloy, with a surface anodizing treatment, a friction coefficient less than 0.01, and it is installed on the processing plane of the frame 1. In the prediction mode, the system continuously monitors the angle deviation. If the data in the subsequent interval returns to the allowable range (such as ±2°), it automatically switches back to the dynamic correction mode.

[0078] Technical effects: 1. The angle segmented calculation and the generation of differential correction amounts improve the compensation accuracy of the local deformation of the elliptical pipeline and reduce the deviation of the cutting position. 2. The real-time calibration link suppresses the cumulative error through periodic calibration, ensuring the consistency between the cutting trajectory and the theoretical path. 3. The abnormal data processing logic quickly identifies the continuous angle deviation, and the prediction mode switch enhances the system's adaptability to sudden deformations. 4. The dynamic correction and the prediction mode work together, reducing the processing interruption frequency under abnormal working conditions and improving the processing continuity.

[0079] The three - level pressure fluctuation determination threshold maintains the processing continuity during mild anomalies and quickly protects the equipment during severe anomalies through a hierarchical response mechanism. The buffer pause program, combined with the feedback of the displacement sensor, ensures that the position accuracy is controllable during the pause and reduces the recovery time. The dynamic threshold calibration is automatically adjusted based on historical data to adapt to different working conditions and reduce the risk of misjudgment. The overall design improves the processing ability of the clamping force fluctuation and ensures the stability and reliability of high - precision pipe cutting.

[0080] According to another embodiment of the present invention, the path correction algorithm divides the pipe rotation angle into multiple independent calculation intervals at a preset interval, and sets the initial proportional relationship between the axial movement speed and the radial feed amount within each interval. The preset interval can be set to one calculation interval per 30°, and the initial proportional relationship is, for example, an axial speed of 1 m / s corresponding to a radial feed amount of 0.5 mm / r. The PLC controller can select an industrial - grade model that supports multi - task processing, and the operation cycle is set to 2 ms. The resolution of the servo - motor encoder can be selected as 17 bits, and the angle data is transmitted to the PLC through a high - speed communication interface. The encoder is fixed to the tail of the servo motor through a flange and synchronously collects data with the displacement sensor of the cutting machine moving mechanism. During the working process, when the pipe rotates to the starting angle of each interval, the PLC generates the initial control instructions for the axial and radial directions according to the preset ratio and sends them to the servo driver through the pulse output port.

[0081] The actual radial displacement data of the cutting machine is collected in real - time and compared with the theoretical calculation value of the current interval. If the deviation exceeds the set threshold (for example, ±0.3 mm), the proportional relationship is dynamically adjusted and the corrected parameters after compensation are generated. The displacement sensor can select a laser - type sensor with a detection accuracy of ±0.02 mm, which is installed on the side of the slide of the cutting machine moving mechanism. The theoretical calculation value is generated based on the angle data of the servo - motor encoder and the preset ratio model, and the deviation threshold is determined by the analog quantity comparison module of the PLC. The adjustment step of the corrected parameters can be set to 0.05 mm / r, and the compensation coefficient is updated in increments of 0.01. During the working process, when the deviation between the actual displacement and the theoretical value exceeds the threshold, the PLC immediately calculates the corrected parameters, adjusts the radial feed rate of the cutting machine through the digital quantity output port, and updates the initial ratio parameters of the next interval at the same time.

[0082] If the angular deviations of consecutive multiple intervals continuously exceed the tolerance range (for example, the deviations of 3 consecutive intervals exceed ±0.5 mm), switch to the prediction correction mode and calculate the path based on the average ratio parameter of the historical processing intervals. The sampling window of the historical data can be set to the last 5 processing cycles, and the average ratio parameter is calculated by the moving average algorithm. The conversion of the pulse control signal adopts the pulse width modulation (PWM) method, and the pulse duty cycle is adjusted by 0.8% - 1.2% corresponding to the axial speed change of every 0.1 m / s. The servo drive can select a model that supports PWM input, and the response time is less than 1 ms. During the working process, when the prediction correction mode is activated, the PLC ignores the real-time angular deviation and directly calls the historical average parameter to generate the control instruction until the displacement sensor detects that the deviation recovers to the allowable range (for example, ±0.2 mm). The corrected pulse signal is transmitted to the servo motor of the cutting machine moving mechanism through a shielded cable to drive the ball screw to perform axial and radial movements.

[0083] Technical effects: Through interval division and dynamic parameter correction, the path deviation can be timely identified and compensated, reducing the cumulative error. The prediction correction mode provides a stable control strategy under continuous abnormal conditions to avoid processing interruption. The high-precision conversion of the pulse signal ensures that the movement of the cutting machine moving mechanism is consistent with the calculated instruction, improving the cutting quality. The overall design enhances the adaptability to complex working conditions and is suitable for the stable processing of elliptical pipes or high-speed rotation scenarios.

[0084] According to an embodiment of the present invention, the implementation steps of the motion correlation model include: real-time collecting the pipeline rotation angle data of the servo motor encoder and the radial displacement data of the cutting machine displacement sensor, and synchronously sampling and calculating the displacement reading change rate through the high-speed input port of the PLC. For example, the preset threshold of the displacement reading change rate can be set to 0.5 mm / s (which can be adjusted according to the pipeline material and wall thickness), and the continuous three sampling periods are set to 30 ms (sampling frequency 33 Hz). When the change rate calculated continuously three times exceeds this threshold, it is determined as the abnormal trigger state of the roundness. At this time, the PLC retrieves the theoretical radial displacement value corresponding to the current angle (calculated based on the standard circular pipeline model), performs differential calculation with the actual displacement value, and generates the primary compensation amount of the radial feed rate. For example, the feed rate is adjusted by 0.2% for every 0.1 mm deviation. The servo motor can select an AC servo motor with an absolute encoder (such as Panasonic MINAS A6 series), and the displacement sensor can select a magnetic grating ruler or a laser displacement sensor (such as Keyence LJ-G series). The encoder is installed at the motor tail and coaxial with the shaft. The displacement sensor is fixed on the side of the cutting machine moving mechanism guide rail, and the detection direction is consistent with the movement direction. The coupling uses an aluminum alloy diaphragm coupling, and the sensor bracket is processed with 45# steel.

[0085] According to the rotation acceleration trend of the encoder's recorded recent five angular intervals (each interval is 15° and the total range is 75°), calculate with a period of 50 ms, predict the pipeline deformation trend of the next interval and generate a secondary dynamic compensation amount. For example, when the acceleration is 0.1 rad / s², the feed rate increases or decreases by 0.5%. After fusing the primary compensation amount and the secondary compensation amount according to the preset weight ratio of 7:3, output it to the servo driver of the cutting machine moving mechanism (such as the supporting Panasonic MBDLN25BE) through an analog signal, and control the feed rate to be adjusted step by step every 50 ms, with each adjustment amplitude not exceeding 3% of the current rate. The ball screw is made of stainless steel, the guide rail slider is made of self-lubricating engineering plastic, the servo driver is installed in the electrical cabinet of the frame, connected to the motor through a power cable, and the PLC motion control module (such as the Siemens S7-1200 technology object) communicates with the driver through a network cable.

[0086] If the displacement sensor reading returns to the normal threshold range of ±0.3 mm within two consecutive pipeline rotation periods (such as 12 seconds corresponding to a rotational speed of 10 r / min), the PLC triggers the compensation cancellation program, and the primary and secondary compensation amounts are each reduced by 50% per period until completely cancelled, and automatically switches to the standard control mode, and performs cutting based on the preset axial speed and radial feed ratio (such as 1:0.8). Parameters such as the normal threshold range and the compensation cancellation rate can be set through the human-machine interface, the control mode switching is realized by Omron G6D series relays, the interface is embedded in the frame operation panel, and the relay module is installed in the electrical cabinet. This mechanism dynamically adjusts the feed rate through multi-source data, effectively deals with abnormal pipeline ovality, reduces trajectory deviation, improves processing adaptability and stability, is suitable for cutting prefabricated pipelines with irregular ovality, and can reduce cutting errors and improve processing efficiency and quality.

[0087] Example: The main structure of the frame can be made of Q345B high-strength steel welded together, with the surface treated by sandblasting for rust prevention, and a T-shaped groove workbench and linear guide rails are arranged inside. The clamping mechanism includes two groups of three-jaw self-centering hydraulic chucks arranged coaxially, and piezoelectric pressure sensors are embedded inside the clamping jaws of the chucks, with the detection direction perpendicular to the pipeline surface. The spacing adjustment range of the chucks can be set to 300 - 1000 mm and is fixed on the frame workbench through a cast iron mounting seat with a locking bolt. The measuring range of the pressure sensor can be selected as 0 - 1000 N, with an accuracy of ±0.5% FS, and the signal is connected to the analog input port of the PLC controller through a shielded cable. After the pipeline enters the clamping area through the conveying device, the two groups of chucks close synchronously to clamp the pipeline, and the pressure sensor monitors the clamping force in real time. When the detected value deviates from the set range (such as 500 N ± 10 N), the PLC triggers the hydraulic pump pressure compensation program.

[0088] The drive motor uses a servo motor with a rated power of 5.5 kW. The output shaft is rigidly connected to the chuck spindle through a jaw coupling. The servo motor is equipped with a 17-bit absolute encoder with a resolution of up to 0.001°, which can real-time feedback the pipe rotation angle to the PLC controller. The cutting actuator includes a disc-type plasma cutting head, and its moving mechanism is driven by a ball screw with a lead of 10 mm. The axial moving speed ranges from 0 to 2 m / s. The displacement sensor selects a magnetic grating scale with a detection accuracy of ±0.01 mm. It is installed on the side of the cutting machine slide, and the detection direction is parallel to the moving guide rail. The PLC controller controls the rotation speed of the servo motor through the pulse output port and starts and stops the cutting machine through the digital quantity output port. When the displacement sensor detects that the cutting trajectory deviation exceeds ±0.2 mm, the PLC calls the path correction algorithm to dynamically adjust the ratio of the axial speed and the radial feed of the cutting machine.

[0089] The PLC controller of the control module is installed in a waterproof electrical cabinet on the side of the frame and communicates with the human-machine interface (HMI) through Ethernet. The HMI uses a 10.4-inch industrial touch screen to real-time display the clamping force fluctuation curve, the rotation speed of the servo motor (unit: rpm) and the cutting trajectory coordinates. The control module has a built-in three-level safety response mechanism: when the clamping force fluctuation exceeds 10% of the upper limit of the set range (for example, 550 N), the rotation speed of the servo motor decreases at a gradient of 2% every 0.5 seconds; if the fluctuation continues to exceed the limit by 15% for 2 seconds (for example, 575 N), the emergency stop of the cutting machine is triggered. After the emergency stop instruction is executed, the servo motor drives the cutting machine to retreat 5°, and the plasma arc is maintained for 0.5 seconds and then cut off to avoid damage to the cutting head. All processing data (such as the peak clamping force, the number of corrections) are automatically stored in the storage module of the HMI and support U disk export.

[0090] Workflow: The pipe is sent into the processing area by the conveying device, and the two groups of chucks are clamped synchronously. The pressure sensor monitors the clamping force in real-time; the servo motor drives the pipe to rotate at a constant speed, and the cutting machine moves according to the preset path. The displacement sensor feedbacks the actual position; the PLC dynamically adjusts the cutting parameters according to the encoder angle data and the displacement feedback, and triggers the step-down speed or emergency stop when the clamping force exceeds the limit; after the processing is completed, the HMI displays and stores the process data. If the equipment is paused due to an abnormality, it will automatically restart at 85% of the original speed after the clamping force is restored.

[0091] Technical effect: Through the rigid design of the frame, the closed-loop pressure control of the clamping mechanism and the precise drive of the servo motor, the equipment significantly improves the pipe clamping stability and the cutting trajectory accuracy. The real-time monitoring and dynamic correction mechanism effectively suppresses the deviation caused by the ovality or clamping fluctuation. The three-level safety response ensures the safety of the processing process. The overall design takes into account high precision and reliability and is suitable for pipe prefabrication under complex working conditions.

[0092] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those skilled in the art, additional modifications can be easily made. Therefore, without departing from the general concept defined by the claims and the equivalent scope, the present invention is not limited to the specific details and the examples shown and described herein.

Claims

1. A cutting device for prefabricating and processing pipelines, characterized in that, It includes a frame, a clamping mechanism, a cutting execution mechanism, a driving motor, and a control module; The clamping mechanism includes a pressure sensor; the driving motor is a servo motor with an absolute encoder; the cutting execution mechanism includes a displacement sensor; The control module includes a PLC controller and a human-machine interface. The PLC controller is connected to the pressure sensor and the displacement sensor through analog input ports, controls the rotation speed of the servo motor through a pulse output port, and controls the start and stop of the cutting machine through a digital output port; The PLC controller has built-in synchronous control logic. When the clamping force fluctuation detected by the pressure sensor exceeds the set range, the rotation speed of the servo motor is synchronously reduced to a preset safety value and a pause instruction for the cutting machine is triggered; The control module is configured with a path correction algorithm, and calculates the proportional relationship between the axial movement speed and the radial feed of the cutting machine in real time according to the pipeline rotation angle data fed back by the servo motor encoder; The human-machine interface displays the clamping force numerical curve, the pipeline rotation angle coordinates, and the displacement trajectory of the cutting machine in real time, and stores the peak clamping force and the number of path corrections during each cutting process; A motion association model is established between the moving mechanism of the cutting machine and the servo motor. When the abnormal reading of the displacement sensor of the cutting machine is caused by the pipeline ovality, the feed rate of the moving mechanism is dynamically adjusted according to the encoder angle data.

2. The cutting device for pipeline prefabrication processing according to claim 1, wherein The clamping mechanism includes two sets of coaxially arranged chucks. The two sets of chucks are fixed on the working table of the frame through an adjustable-spacing mounting seat, and a pressure sensor is embedded inside each set of chucks; A pressure closed-loop adjustment unit is set in the opening and closing control circuit of the chuck. When the deviation between the detected value of the pressure sensor and the set value continuously exceeds 5 seconds, the hydraulic pump pressure supplement program is automatically started until the pressure is stabilized within the tolerance band; The driving motor is a servo motor with an absolute encoder. The output shaft of the servo motor is rigidly connected to the rotating main shaft of at least one set of chucks through a coupling; The cutting execution mechanism includes a disc-type cutting machine that can move radially along the pipeline. A displacement sensor is installed on the moving mechanism of the cutting machine, and the detection direction of the displacement sensor is consistent with the movement direction of the cutting machine.

3. The cutting device for pipe prefabrication processing according to claim 1, characterized in that, The PLC controller has a built-in dynamic compensation algorithm, establishes a linear association model between the real-time clamping force fluctuation value detected by the pressure sensor and the pipeline rotation angle data fed back by the servo motor encoder, and outputs a compensation coefficient of the axial movement speed of the cutting machine to the moving mechanism of the cutting machine; The human-machine interface is provided with a data synchronous display unit, which parallelly displays the clamping force fluctuation curve, the real-time rotation speed value of the servo motor, and the trajectory model of the displacement trajectory of the cutting machine on the touch screen interface; When the dynamic compensation algorithm detects that the clamping force fluctuation exceeds the set threshold, a segmented decreasing instruction sequence of the radial feed of the cutting machine is generated according to the current rotation speed of the servo motor; A rotation speed closed-loop control link is established between the PLC controller and the servo motor driver. When the displacement sensor of the cutting machine detects the deviation between the actual displacement and the calculated path, the angular acceleration compensation value of the servo motor is adjusted in the reverse direction.

4. The cutting device for pipe prefabrication processing according to claim 1, characterized in that: A dynamic frequency modulation unit is provided between the pulse output port of the PLC controller and the servo motor driver. This unit dynamically adjusts the output pulse frequency according to the clamping force data detected by the pressure sensor in real time. The adjustment range of the pulse frequency is limited to 70%-130% of the reference frequency corresponding to the rated speed of the servo motor; The digital output port is configured with a start-stop safety interlock logic. When the displacement sensor detects that the initial position of the cutting machine moving mechanism deviates from the set origin by more than 1 mm, the start command of the cutting machine is automatically locked until the position is calibrated; The dynamic frequency modulation unit establishes a closed-loop feedback link with the servo motor encoder. The actual speed data fed back by the encoder is processed by the proportional integral algorithm to generate a compensation increment of the pulse frequency; The start-stop safety interlock logic integrates a delay trigger mechanism. After receiving the stop command of the cutting machine, the plasma arc is maintained for 0.5 seconds and then the power is cut off. At the same time, the servo motor is forced to perform a 5° angle reverse movement; The pulse output port is set with an overload protection mode. When the detected value of the servo motor current continuously exceeds 120% of the rated current for 3 seconds, the pulse frequency is automatically reduced to 50% of the reference frequency and a touch screen alarm pop-up window is triggered; 5. The cutting device for pipe prefabrication processing according to claim 1, characterized in that: The synchronous control logic includes a multi-level response mechanism. When the pressure sensor detects that the clamping force fluctuation value exceeds 10% of the upper limit of the set range, the speed of the servo motor is linearly reduced to 80% of the preset safety value, and at the same time, a cutting machine pause preparation signal is sent to the digital output port; When the clamping force fluctuation value continuously exceeds 15% of the upper limit of the set range for 2 seconds, the speed of the servo motor is forcibly switched to 50% of the preset safety value, and an emergency stop command for the cutting machine is sent through the digital output port; During the pause of the cutting machine, the PLC controller continuously monitors the data of the pressure sensor. If the clamping force fluctuation value returns to the set range within 5 seconds, the servo motor is automatically restarted and the operation is resumed at 90% of the original speed; The synchronous control logic and the displacement sensor establish a linkage judgment condition. When the offset of the cutting machine displacement trajectory exceeds 2 times the axial movement speed compensation coefficient, the servo motor speed reduction operation is preferentially performed and then the cutting machine is paused; The calculation of the preset safety value is based on the average speed of the last 10 processing cycles recorded by the servo motor encoder, and a dynamic speed threshold is generated through conversion by the reference frequency of the pulse output port; 6. The pipe prefabrication and processing cutting equipment according to claim 1, characterized in that: The calculation process of the proportional relationship includes a data segmentation processing module. The pipe rotation angle fed back by the servo motor encoder is divided into independent calculation intervals every 15°. In each interval, the slope parameter of the radial feed amount is dynamically corrected according to the cumulative value of the axial movement speed; The data segmentation processing module and the displacement sensor establish a feedback verification mechanism. When the deviation between the actual radial feed amount and the calculated value exceeds 5% of the axial movement speed, a slope parameter recalculation command for the current calculation interval is automatically triggered; At the end of each pipe rotation cycle, the PLC controller extracts the radial feed correction data of the nearest three intervals to generate a prediction reference value for the axial movement speed of the next cycle; The calculation result of the proportional relationship is converted into a control signal for the cutting machine movement mechanism through pulse width modulation. For every 0.1 m / s change in the axial movement speed, the pulse duty cycle is adjusted by 0.8% - 1.2%; The data segmentation processing module has an angle compensation logic built-in. When the change rate of the rotational angle acceleration in two consecutive calculation intervals is detected to exceed 0.5 rad / s², the radial feed slope parameter is forced to be locked as the moving average of the previous three intervals.

7. The pipe prefabrication cutting equipment according to claim 1, characterized in that: The synchronous control logic sets three levels of pressure fluctuation determination thresholds. The first-level threshold is 8% of the upper limit of the set range, triggering the servo motor speed to decrease in a gradient of 2% every 0.5 seconds, and at the same time sending a preparation pause signal to the cutting machine; The second-level threshold is 12% of the upper limit of the set range, forcing the servo motor speed to be locked at 60% of the current value, and starting a 0.3-second buffer pause program for the cutting machine; The third-level threshold is 20% of the upper limit of the set range, immediately cutting off the servo motor enable signal and switching the cutting machine power supply to the standby mode; After triggering the pause instruction, the PLC controller continuously collects the pressure sensor data. If the pressure fluctuation value drops back within the set range within 3 consecutive sampling cycles, the servo motor is restarted at 85% of the original speed and the cutting machine operation is resumed; During the execution of the buffer pause program, the real-time position data of the displacement sensor is read synchronously to maintain the position error of the axial movement mechanism within ±0.15 mm during the pause of the cutting machine; The values of the three-level pressure fluctuation determination thresholds are dynamically updated according to the standard deviation of the clamping force in the last 5 normal processing cycles recorded by the servo motor encoder, and the update period is automatically calibrated before the start of each processing task.

8. The pipe prefabrication cutting equipment according to claim 1, characterized in that: The path correction algorithm sets an angle segmentation calculation mechanism, dividing the pipe rotation angle fed back by the servo motor encoder into calculation intervals every 30°, and dynamically calculating the differential correction amount of the radial feed within each interval according to the real-time value of the axial movement speed; At the end of each calculation interval, the PLC controller makes a differential comparison between the actual radial displacement detected by the displacement sensor and the calculated value. When the cumulative deviation exceeds 3% of the axial movement speed, an inverse correction instruction for the compensation coefficient of the next interval is automatically generated; The change rate parameter of the servo motor speed is introduced into the calculation process of the differential correction amount, and the rotational acceleration value is multiplied by the current value of the axial movement speed as the dynamic adjustment factor of the radial feed; The path correction algorithm establishes a real-time calibration link with the cutting machine displacement sensor. After the axial movement mechanism completes a 2-mm stroke each time, a position calibration operation of the radial feed is forced to be triggered; The built-in abnormal data processing logic of the angle segmentation calculation mechanism automatically switches to a prediction calculation mode based on the average angular velocity of the previous five intervals when the deviation of the pipeline rotation angle increment in three consecutive calculation intervals exceeds 5°.

9. The cutting device for pipe prefabrication processing according to claim 1, wherein, The path correction algorithm includes the following steps: a) Divide the pipeline rotation angle into multiple independent calculation intervals at a preset interval, and set the initial proportional relationship between the axial movement speed and the radial feed in each interval; b) Real-time collect the actual radial displacement data of the cutting machine and compare it with the theoretical calculated value of the current interval. If the deviation exceeds the set threshold, dynamically adjust the proportional relationship to generate corrected parameters after compensation; c) When switching between adjacent intervals, extract the rotational acceleration trend data of the servo motor, and dynamically adjust the correction amplitude of the radial feed in combination with the current axial movement speed according to the preset weight coefficient; d) If the angle deviation in multiple consecutive intervals continuously exceeds the tolerance range, switch to the prediction correction mode, and calculate the path based on the average proportional parameter of the historical processing interval until the deviation returns to the allowable range; e) Convert the corrected proportional parameter into a pulse control signal, and control the axial speed and radial feed action of the cutting machine moving mechanism by adjusting the pulse duty cycle.

10. The pipe prefabrication processing cutting device according to claim 1, characterized in that, The implementation of the motion correlation model includes the following steps: Real-time collect the pipeline rotation angle data of the servo motor encoder and the radial displacement data of the cutting machine displacement sensor, calculate the change rate of the displacement reading, and if the change rate exceeds the preset threshold in three consecutive sampling periods, it is determined as the ellipticity anomaly trigger state; In the anomaly trigger state, extract the theoretical radial displacement value corresponding to the current pipeline rotation angle, and perform a differential calculation with the actual displacement value to generate a primary compensation amount for the radial feed rate; According to the rotation acceleration trend of the last five angle intervals recorded by the encoder, predict the pipeline deformation trend of the next interval, and superimpose it to generate a secondary dynamic compensation amount for the feed rate; Fuse the primary compensation amount and the secondary dynamic compensation amount according to the preset weight, and output it to the servo driver of the cutting machine moving mechanism to control the feed rate to be adjusted step by step in an increasing or decreasing manner; If the displacement sensor reading returns to the normal threshold range within two consecutive pipeline rotation periods, gradually cancel the compensation amount and switch to the standard control mode.

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