A double-chuck synchronous control and eccentricity detection protection system and method for a laser pipe cutting machine

Abstract

The application provides a double-chuck synchronous control and eccentricity detection protection system and method for a laser pipe cutting machine, and belongs to the technical field of laser pipe cutting equipment control. The system comprises a front-chuck driving module, a rear-chuck driving module, a data acquisition module, a synchronous controller and a hierarchical protection executor. The data acquisition module acquires actual rotation angle values and output load torque values of the double chucks in real time. The synchronous controller takes the front chuck as a driving shaft and the rear chuck as a driven shaft, performs closed-loop synchronous control based on actual position deviation, dynamically compensates the following position of the driven shaft according to double-shaft transmission parameters, and realizes physical rotation synchronization of the double chucks. The synchronous controller also determines pipe eccentricity faults and identifies fault levels according to whether the angle deviation and the torque deviation exceed the threshold value in a plurality of continuous rotation cycles. The hierarchical protection executor executes corresponding protection actions according to the fault levels. The application does not need additional sensors, has high synchronization accuracy, can identify pipe eccentricity faults and perform hierarchical protection.

Description

Technical Field

[0001] The present application belongs to the technical field of laser pipe cutting equipment control, and specifically relates to a double-chuck synchronous control and eccentricity detection protection system and method for a laser pipe cutting machine. Background Art

[0002] Laser pipe cutting machines widely adopt front and rear double chucks to clamp the pipe and drive it to rotate continuously, and cooperate with the laser cutting head to complete processes such as pipe cutting, hole opening, and bevel machining. The double chucks must maintain strict phase synchronization during the rotation process. If the rotation angles of the front and rear chucks are inconsistent, the pipe will be subjected to additional torsional stress, which in mild cases will lead to inclined cutting end faces, dislocated intersecting lines, and deformed pipe orifices, and in severe cases will cause overall torsional plastic deformation of thin-walled pipes, and even trigger safety accidents where the pipe swings and collides with the equipment protective cover. Therefore, the double-chuck synchronous control technology is the core link that determines the machining accuracy and operation safety of the laser pipe cutting machine.

[0003] Existing laser pipe cutting machines generally realize double-chuck synchronization by means of a host computer issuing the same position or speed command to a lower-level drive system. However, this method can only ensure the numerical consistency at the command level. In actual motion, there are differences in the response delay of the servo drive systems respectively matched with the front and rear chucks, and there are manufacturing and assembly backlashes in the mechanical transmission chains (such as reducers, timing belts, gear racks, etc.), which gradually expand with different degrees of operation wear. The above factors lead to a gradual accumulation of deviation between the actual physical rotation angles of the front and rear chucks even if the commands are completely the same. Since both ends of the pipe are rigidly clamped by the two chucks, the accumulated rotation angle deviation will be converted into torsional stress inside the pipe. When the stress exceeds the elastic limit or yield limit of the pipe, it will cause irreversible machining errors or pipe damage.

[0004] In addition, when the pipe itself is bent, the end face is not cut flat, or the end of the clamping jaw does not clamp the pipe at the rotation center of the chuck, periodic eccentric swing will occur during the rotation of the pipe. The eccentric swing subjects the front and rear chucks to alternating radial loads, which in severe cases causes severe equipment vibration and premature fatigue damage of the bearings, and also affects the stability of the cutting head performing focus tracking following the outer wall of the pipe. Existing equipment lacks the online identification capability for this eccentric state. Some solutions attempt to indirectly judge eccentricity through the rotation angle position fluctuation of a single chuck, but this method is very likely to misjudge normal disturbances such as mechanical transmission ripples and servo tracking jitters as eccentricity faults, resulting in frequent false alarms and unnecessary shutdowns, which seriously affects machining efficiency and equipment operation rate. Summary of the Invention

[0005] In a first aspect, the embodiments of the present application provide a double-chuck synchronous control and eccentricity detection protection system for a laser pipe cutting machine, comprising a front chuck drive module, a rear chuck drive module, a data acquisition module, a synchronous controller and a graded protection actuator; The front chuck drive module is connected to the front chuck drive of the laser tube cutting machine, and the rear chuck drive module is connected to the rear chuck drive of the laser tube cutting machine. The data acquisition module is connected to both the front chuck drive module and the rear chuck drive module, and is used to acquire the actual rotation angle value and the real-time output load torque value of the front and rear chucks in real time. The synchronization controller is connected to the data acquisition module, the front chuck driver module, and the rear chuck driver module, and is configured as follows: The front chuck is the active follower of the command axis, and the rear chuck is the driven follower of the actual position axis. The actual rotation angle deviation between the two axes is calculated in real time and the speed output of the driven follower of the actual position axis is dynamically corrected to synchronize the physical phase of the two chucks. Based on the transmission parameters of the front and rear chucks, the target following position of the driven following shaft is dynamically compensated. Compare whether the actual rotation angle deviation between the front chuck and the rear chuck and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determine the pipe eccentricity fault and identify the pipe eccentricity fault level when they all exceed the preset thresholds. The graded protection actuator is connected to the synchronous controller and is used to perform graded protection actions according to the identified level of pipe eccentricity fault.

[0006] Secondly, embodiments of this application also provide a method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine, based on the system described in the first aspect, including the following steps: S1. The data acquisition module collects the actual rotation angle value of the front chuck and the rear chuck and the real-time output load torque value in real time, and outputs them to the synchronous controller. S2. The synchronous controller calculates the actual rotation angle deviation between the two axes based on the actual rotation angle values ​​of the front chuck and the rear chuck, with the front chuck as the active following command axis and the rear chuck as the driven following actual position axis. It then dynamically corrects the output speed of the driven axis accordingly, so that the physical phase of the two chucks is synchronized. S3. The synchronous controller acquires the transmission parameters of the front chuck and the rear chuck respectively, performs dynamic compensation on the target following position of the driven following actual position shaft, and uses the compensated target following position as the reference for correcting the speed of the driven following actual position shaft. S4. The synchronous controller calculates the real-time output load torque deviation between the front and rear chucks based on their respective actual rotation angle values ​​and real-time output load torque values, as well as the actual rotation angle deviation calculated by the synchronous controller. It compares whether the actual rotation angle deviation and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determines the pipe eccentricity fault and identifies the pipe eccentricity fault level when both exceed the thresholds. S5. The graded protection actuator obtains the pipe eccentricity fault judgment result and fault level identified by the synchronous controller, and executes the corresponding graded protection action according to the fault level.

[0007] As can be seen from the above technical solutions, this application has the following advantages: The laser tube cutting machine dual-chuck synchronous control and eccentricity detection and protection system and method provided in this application acquires the actual rotation angle and load torque of the dual chucks in real time, performs closed-loop control with the front chuck as the driving shaft and the rear chuck as the driven shaft, and combines dynamic electronic gear compensation to achieve physical phase synchronization, avoiding torsional stress on the tube caused by asynchrony and ensuring cutting accuracy. No additional sensors are required; by analyzing the angle and torque deviation of the dual axes in a continuous cycle, it can reliably identify tube eccentricity faults and effectively filter mechanical vibration interference, reducing false alarm rates. It can also adaptively switch between rigid and flexible synchronization modes according to the tube wall thickness, enhancing versatility. Furthermore, it implements a graded protection strategy for faults, automatically reducing speed and issuing warnings for minor faults to maintain production, and immediately stopping for serious faults to ensure safety. While ensuring equipment and personnel safety, it maximizes production efficiency. Attached Figure Description

[0008] To more clearly illustrate the technical solution of this application, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1 This is a schematic diagram of the dual chuck synchronous control and eccentricity detection and protection system for the laser tube cutting machine of the present invention.

[0010] Figure 2 This is a schematic diagram of the front chuck drive module of the present invention.

[0011] Figure 3 This is a schematic diagram of the rear chuck drive module of the present invention.

[0012] Figure 4 This is a schematic diagram of the data acquisition module of the present invention.

[0013] Figure 5 This is a flowchart illustrating the method for synchronous control and eccentricity detection and protection of the dual chucks in a laser tube cutting machine according to the present invention. Detailed Implementation

[0014] The dual-chuck synchronous control and eccentricity detection protection system for laser tube cutting machines will be described in detail below, providing a more comprehensive overview of various embodiments of this disclosure. This disclosure may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of this disclosure to the specific embodiments disclosed herein, but rather this disclosure should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of this disclosure.

[0015] This embodiment provides a dual-chuck synchronous control and eccentricity detection and protection system for a laser pipe cutting machine, which achieves high-precision physical synchronization of the dual chucks, intelligently detects pipe eccentricity, and performs graded protection.

[0016] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Please see Figure 1 The diagram shown is a schematic of a dual-chuck synchronous control and eccentricity detection and protection system for a laser tube cutting machine in a specific embodiment. The system includes a front chuck drive module, a rear chuck drive module, a data acquisition module, a synchronous controller, and a graded protection actuator. The front chuck drive module is connected to the front chuck drive of the laser tube cutting machine, and the rear chuck drive module is connected to the rear chuck drive of the laser tube cutting machine. It should be noted that the front chuck drive module is connected to the front chuck drive of the laser tube cutting machine, providing independent rotational drive force for the front chuck. It has three-loop closed-loop control capabilities of position, speed, and current, ensuring the stability and response consistency of the single-axis operation of the drive shaft. The rear chuck drive module is connected to the rear chuck drive of the laser tube cutting machine, providing independent rotational drive force for the rear chuck. It has three-loop closed-loop control capabilities of position, speed, and current, ensuring that the driven shaft can accurately execute the dynamic correction commands issued by the synchronous controller. The data acquisition module is connected to both the front chuck drive module and the rear chuck drive module, and is used to acquire the actual rotation angle value and the real-time output load torque value of the front and rear chucks in real time. It should be noted that the data acquisition module collects the actual rotation angle and output load torque of the dual chucks in real time, providing the synchronous controller with real and real-time feedback signals, which is the basis for realizing closed-loop control and status monitoring. The synchronization controller is connected to the data acquisition module, the front chuck driver module, and the rear chuck driver module, and is configured as follows: The front chuck is the active follower of the command axis, and the rear chuck is the driven follower of the actual position axis. The actual rotation angle deviation between the two axes is calculated in real time and the speed output of the driven follower of the actual position axis is dynamically corrected to synchronize the physical phase of the two chucks. Based on the transmission parameters of the front and rear chucks, the target following position of the driven following shaft is dynamically compensated. Compare whether the actual rotation angle deviation between the front chuck and the rear chuck and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determine the pipe eccentricity fault and identify the pipe eccentricity fault level when they all exceed the preset thresholds. It should be noted that the synchronous controller realizes intelligent control including calculating deviation, generating compensation commands, and judging fault levels, thereby achieving high precision and high reliability of the entire system. The graded protection actuator is connected to the synchronous controller and is used to perform graded protection actions according to the identified level of pipe eccentricity fault. It should be noted that the graded protection actuator translates the diagnostic results into specific protective actions, directly ensuring the safety of equipment and personnel.

[0018] This embodiment achieves high-precision physical synchronization through dual-axis closed-loop control and dynamic compensation; it intelligently analyzes angle and torque deviations to reliably identify pipe eccentricity; and it implements graded protection to maximize production efficiency while ensuring safety.

[0019] Furthermore, as a refinement and extension of the specific implementation methods described above, and to fully illustrate the specific implementation process in this embodiment, another laser tube cutting machine dual-chuck synchronous control and eccentricity detection and protection system is provided, such as... Figure 1 As shown, the system includes a front chuck drive module, a rear chuck drive module, a data acquisition module, a synchronization controller, and a graded protection actuator. The front chuck drive module is connected to the front chuck drive of the laser tube cutting machine, and the rear chuck drive module is connected to the rear chuck drive of the laser tube cutting machine. The data acquisition module is connected to both the front chuck drive module and the rear chuck drive module, and is used to acquire the actual rotation angle value and the real-time output load torque value of the front and rear chucks in real time. The synchronization controller is connected to the data acquisition module, the front chuck driver module, and the rear chuck driver module, and is configured as follows: The front chuck is the active follower of the command axis, and the rear chuck is the driven follower of the actual position axis. The actual rotation angle deviation between the two axes is calculated in real time and the speed output of the driven follower of the actual position axis is dynamically corrected to synchronize the physical phase of the two chucks. Based on the transmission parameters of the front and rear chucks, the target following position of the driven following shaft is dynamically compensated. Compare whether the actual rotation angle deviation between the front chuck and the rear chuck and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determine the pipe eccentricity fault and identify the pipe eccentricity fault level when they all exceed the preset thresholds. The graded protection actuator is connected to the synchronous controller and is used to perform graded protection actions according to the identified level of pipe eccentricity fault. The front chuck drive module includes a front chuck servo driver and a front chuck servo motor, and the rear chuck drive module includes a rear chuck servo driver and a rear chuck servo motor. like Figure 2 As shown, the front chuck servo driver includes a first current regulator, a first speed regulator, a first position regulator, a first current sensor, and a first encoder interface. The output terminal of the first current regulator is connected to the three-phase winding terminal of the front chuck servo motor. The detection terminal of the first current sensor is set on the power supply line between the first current regulator and the front chuck servo motor. The feedback output terminal of the first current sensor is connected to the feedback input terminal of the first current regulator. The output terminal of the first speed regulator is connected to the command input terminal of the first current regulator. The output terminal of the first position regulator is connected to the command input terminal of the first speed regulator. The input terminal of the first encoder interface is connected to the encoder signal terminal mounted on the front chuck shaft. The position feedback output terminal of the first encoder interface is connected to the feedback input terminal of the first position regulator. The speed feedback output terminal of the first encoder interface is connected to the feedback input terminal of the first speed regulator. like Figure 3 As shown, the rear chuck servo driver includes a second current regulator, a second speed regulator, a second position regulator, a second current sensor, and a second encoder interface. The output of the second current regulator is connected to the three-phase winding of the rear chuck servo motor. The detection end of the second current sensor is located on the power supply line between the second current regulator and the rear chuck servo motor. The feedback output of the second current sensor is connected to the feedback input of the second current regulator. The output of the second speed regulator is connected to the command input of the second current regulator. The output of the second position regulator is connected to the command input of the second speed regulator. The input of the second encoder interface is connected to the encoder signal end mounted on the rear chuck shaft. The position feedback output of the second encoder interface is connected to the feedback input of the second position regulator. The speed feedback output of the second encoder interface is connected to the feedback input of the second speed regulator. like Figure 4 As shown, the data acquisition module includes a front chuck actual rotation angle sensor, a rear chuck actual rotation angle sensor, a front chuck output torque sensor, a rear chuck output torque sensor, and a data acquisition card. The actual rotation angle sensor of the front chuck is installed on the rotating shaft of the front chuck, and the actual rotation angle sensor of the rear chuck is installed on the rotating shaft of the rear chuck. The front chuck output torque sensor is set at the output end of the front chuck drive module, and the rear chuck output torque sensor is set at the output end of the rear chuck drive module. The data acquisition card is connected to the front chuck actual rotation angle sensor, the rear chuck actual rotation angle sensor, the front chuck output torque sensor, the rear chuck output torque sensor, and the synchronous controller.

[0020] In this embodiment, the front and rear chuck servo drivers employ a three-loop cascade control structure consisting of a position loop, a speed loop, and a current loop. The position loop generates a speed command by comparing the position command issued by the host computer or synchronous controller with the actual position fed back by the encoder. The speed loop compares the speed command with the actual rotational speed fed back by the encoder to generate a current command. The current loop compares the current command with the actual current fed back by the current sensor to generate a drive voltage output to the servo motor. These three loops are connected in series, converging sequentially from the outside in, ensuring the stability and consistent response of each chuck's single-axis operation.

[0021] In this application, the synchronization controller abandons the traditional method of the host computer directly issuing synchronization commands to the slave chuck, and instead adopts a cross-coupled master-slave follower structure. The active chuck (i.e., the front chuck) follows the machining commands from the host computer, while the slave chuck (i.e., the rear chuck) follows the actual running position of the active chuck, rather than the commanded position. Specifically, the synchronization controller acquires the actual rotation angle of the front chuck from the data acquisition module in real time. and rear chuck actual turning angle Calculate the actual rotation angle deviation ; then The speed compensation amount is generated by proportional-integral (PI) adjustment. This is superimposed on the original speed command of the driven chuck to output the final speed command. The chuck drive module is then connected. This closed-loop correction mechanism effectively eliminates the problem of asynchronous actual positions caused by factors such as servo response delay, transmission backlash, and load changes.

[0022] To address structural synchronization deviations caused by inconsistencies in the reduction ratios and drive pitches of the front and rear chucks, the synchronization controller incorporates an adaptive compensation function for uneven pitch transmissions. The synchronization controller acquires the drive pitch of the front chuck separately. and reduction ratio The drive pitch of the rear chuck and reduction ratio Real-time calculation of dynamic electronic gear compensation coefficient ; then the actual rotation angle of the chuck Using this as a reference, calculate the target following position of the driven axis. This serves as a reference for correcting the driven shaft speed. Through this compensation mechanism, regardless of whether the mechanical transmission parameters of the dual chucks are consistent, complete synchronization between the actual rotational linear velocity of the pipe and the circumferential feed rate can be achieved, eliminating structural fixed deviations and cumulative deviations at their source.

[0023] like Figure 5 As shown, the following are embodiments of the laser tube cutting machine dual chuck synchronous control and eccentricity detection and protection method provided in this disclosure. This method belongs to the same inventive concept as the laser tube cutting machine dual chuck synchronous control and eccentricity detection and protection system in the above embodiments. For details not described in detail in the embodiments of the laser tube cutting machine dual chuck synchronous control and eccentricity detection and protection method, please refer to the embodiments of the laser tube cutting machine dual chuck synchronous control and eccentricity detection and protection system described above.

[0024] The method includes the following steps: S1. The data acquisition module collects the actual rotation angle value of the front chuck and the rear chuck and the real-time output load torque value in real time, and outputs them to the synchronous controller. It should be noted that by acquiring the angle and torque data of the dual chucks in real time, accurate and timely raw data input is provided for subsequent control and judgment. S2. The synchronous controller calculates the actual rotation angle deviation between the two axes based on the actual rotation angle values ​​of the front chuck and the rear chuck, with the front chuck as the active following command axis and the rear chuck as the driven following actual position axis. It then dynamically corrects the output speed of the driven axis accordingly, so that the physical phase of the two chucks is synchronized. It should be noted that, based on the actual angular deviation, the driven shaft speed is dynamically corrected to actively eliminate the physical angular difference generated by the double chucks during operation, ensuring that the pipe is not twisted and guaranteeing processing accuracy; S3. The synchronous controller acquires the transmission parameters of the front chuck and the rear chuck respectively, performs dynamic compensation on the target following position of the driven following actual position shaft, and uses the compensated target following position as the reference for correcting the speed of the driven following actual position shaft. It should be noted that by compensating for the target position of the driven shaft based on the transmission parameters, systematic errors caused by differences in mechanical structure (such as different reduction ratios and pitches) can be compensated in advance, making the basis of synchronous control more accurate. S4. The synchronous controller calculates the real-time output load torque deviation between the front and rear chucks based on their respective actual rotation angle values ​​and real-time output load torque values, as well as the actual rotation angle deviation calculated by the synchronous controller. It compares whether the actual rotation angle deviation and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determines the pipe eccentricity fault and identifies the pipe eccentricity fault level when both exceed the thresholds. It should be noted that by comprehensively analyzing angular deviation and torque deviation and making judgments within a continuous cycle, the eccentricity of the pipe can be automatically and reliably identified, and the fault level can be distinguished, providing a decision basis for graded protection. Simultaneously, eccentricity fault identification is performed using two dimensions: angular deviation and torque deviation. The physical principle is as follows: When the pipe clamping is misaligned or the pipe itself is bent, the pipe will bear a periodic alternating bending load during one rotation. The pipe exerts periodic opposing forces on the front and rear chucks, causing an imbalance in the load on the two chucks. The larger the pipe eccentricity e, the larger the alternating bending moment M generated by the rotation (M∝e). The servo output torque is used to balance the pipe bending moment, and the difference in output torque between the two chucks is... As the eccentricity e increases monotonically; under concentric conditions, the pipe has no additional alternating bending moment, and the loads on the two chucks are nearly identical. The value is very small; angular deviation This directly reflects the degree of asynchrony in the physical rotation angles of the two chucks; by simultaneously monitoring... and These two parameters can comprehensively and accurately identify faults such as pipe eccentricity, bending, or loose clamps. S5. The graded protection actuator obtains the pipe eccentricity fault judgment result and fault level identified by the synchronous controller, and executes the corresponding graded protection action according to the fault level. It should be noted that different protection strategies are implemented according to the fault level to ensure equipment safety while maintaining production as much as possible, thus achieving the optimal combination of safety and economy.

[0025] This embodiment achieves closed-loop synchronization of dual chucks based on actual position cross-coupling, is compatible with devices with different pitches and reduction ratios, monitors angular deviation and torque deviation, accurately identifies eccentric faults, is suitable for both rigid and flexible pipes, and provides graded protection that balances efficiency and safety, without the need for additional sensors.

[0026] Furthermore, as a refinement and extension of the specific implementation methods of the above embodiments, in order to fully illustrate the specific implementation process of this embodiment, another method for synchronous control and eccentricity detection and protection of a dual chuck in a laser tube cutting machine is provided, such as... Figure 5 As shown, the method includes the following steps: S1. The data acquisition module collects the actual rotation angle value of the front chuck and the rear chuck and the real-time output load torque value in real time, and outputs them to the synchronous controller. The specific steps of step S1 are as follows: S11. Front chuck actual rotation angle sensor detects the actual rotation angle value of the front chuck. And output it to the data acquisition card; S12. The rear chuck actual rotation angle sensor detects the actual rotation angle value of the rear chuck. And output it to the data acquisition card; S13. The front chuck output torque sensor detects the real-time output load torque value of the front chuck. And output it to the data acquisition card; S14. The rear chuck output torque sensor detects the real-time output load torque value of the rear chuck. And output it to the data acquisition card; S15. Data acquisition card synchronously acquires the actual rotation angle value of the chuck before the data acquisition card. The actual rotation angle of the rear chuck Real-time output load torque value of the front chuck Real-time output load torque value of the rear chuck And output to the synchronous controller respectively; S2. The synchronous controller calculates the actual rotation angle deviation between the two axes based on the actual rotation angle values ​​of the front chuck and the rear chuck, with the front chuck as the active following command axis and the rear chuck as the driven following actual position axis. It then dynamically corrects the output speed of the driven axis accordingly, so that the physical phase of the two chucks is synchronized. The specific steps of step S2 are as follows: S21. The synchronous controller acquires the actual rotation angle value of the front chuck. and the actual rotation angle of the rear chuck Calculate the actual rotation angle deviation between the front chuck and the rear chuck. ; S22. The synchronous controller will adjust the actual rotation angle deviation. The speed compensation amount for the driven axis following the actual position is generated through proportional-integral adjustment. ; in, For synchronous proportional gain, Synchronous integral gain; S23. The synchronous controller will automatically follow the original command speed of the actual position axis. With speed compensation amount Superimpose and calculate the final output speed of the driven shaft that follows the actual position. And send it to the rear chuck drive module to correct the speed output of the driven follower shaft at the actual position; S3. The synchronous controller acquires the transmission parameters of the front chuck and the rear chuck respectively, performs dynamic compensation on the target following position of the driven following actual position shaft, and uses the compensated target following position as the reference for correcting the speed of the driven following actual position shaft. The specific steps of step S3 are as follows: S31. The synchronous controller obtains the drive pitch of the front chuck. and reduction ratio and the drive pitch of the rear chuck and reduction ratio Calculate the dynamic electronic gear compensation coefficient ; S32. The synchronization controller adjusts the actual rotation angle of the front chuck. and dynamic electronic gear compensation coefficient Calculate the target following position of the driven following axis. And will follow the target position of the actual position axis. As a following reference for speed correction of the driven shaft following the actual position; S33. The synchronous controller acquires the wall thickness parameters of the pipe; When the pipe wall thickness parameter is greater than the preset wall thickness threshold (e.g., 3mm), proceed to step S34; When the pipe wall thickness parameter is less than the preset wall thickness threshold (e.g., 3mm), proceed to step S35; S34. The synchronous controller determines that the pipe is a rigid pipe and adjusts the synchronous proportional gain. and synchronous integral gain Set to the first gain value and execute rigid synchronization mode; In rigid synchronization mode, the synchronization controller uses a first gain value to measure the actual rotation angle deviation. The speed compensation amount for the driven axis following the actual position is generated through proportional-integral adjustment. and speed compensation amount The original command speed is directly superimposed on the driven axis following the actual position. To correct the output speed of the driven shaft; S35. The synchronous controller determines that the pipe is a flexible pipe and adjusts the synchronous proportional gain. and synchronous integral gain Set to the second gain value, which is less than the first gain value, and execute the flexible synchronization mode. In flexible synchronization mode, the synchronization controller uses a second gain value to calculate the actual rotation angle deviation. The speed compensation amount for the driven axis following the actual position is generated through proportional-integral adjustment. and in speed compensation amount Superimposed on the original command speed of the driven follower axis in actual position Previously, the speed compensation amount Jerk filtering with jerk is applied to limit the instantaneous torque during correction; In this embodiment, rigid pipes refer to steel pipes or thick-walled profiles with a wall thickness ≥3mm. Their cross-sectional bending stiffness is high, and they are not prone to elastic deformation under the action of correction torque. Therefore, high gain can be used to achieve rapid phase correction and ensure synchronization accuracy. Flexible pipes refer to thin-walled round pipes or thin-walled square pipes with a wall thickness <3mm. Their cross-sectional bending stiffness is low. If the correction torque is too large or changes too quickly, they are prone to elastic deformation or even plastic deformation. Therefore, for flexible pipes, low gain combined with jerk filtering with jerk is used to make the speed compensation change gradually, limit the instantaneous correction torque, and thus avoid the pipe being stretched and deformed while ensuring synchronization. S4. The synchronous controller calculates the real-time output load torque deviation between the front and rear chucks based on their respective actual rotation angle values ​​and real-time output load torque values, as well as the actual rotation angle deviation calculated by the synchronous controller. It compares whether the actual rotation angle deviation and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determines the pipe eccentricity fault and identifies the pipe eccentricity fault level when both exceed the thresholds. The specific steps of step S4 are as follows: S41. The synchronous controller acquires the real-time output load torque value of the front chuck from the data acquisition module. Real-time output of load torque value from the rear chuck Calculate the real-time output load torque deviation between the front and rear chucks. ; S42. Synchronous controller for actual rotation angle deviation and real-time output load torque deviation A sliding window averaging filter is performed to eliminate instantaneous mechanical jitter interference; the sliding window averaging process involves taking the arithmetic mean of M consecutive sampled values ​​as the filtered output value at the current moment, where M≥3; S43. The synchronous controller compares the actual rotation angle deviation after filtering. and real-time output load torque deviation Whether the preset threshold is exceeded in each of N consecutive pipe rotation cycles, where N≥3; If so, determine the pipe eccentricity fault and identify the fault level, and output the determination result and fault level to the graded protection actuator. If not, determine to continue monitoring and return to step S41; In step S4, the calibration and tuning method for the preset threshold is as follows: S401. Select a standard pipe that meets the preset straightness requirements, and clamp the standard pipe onto the front chuck and the rear chuck according to the preset coaxiality requirements; S402. Control the front and rear chucks to run at a preset operating speed; S403. The data acquisition module acquires the actual rotation angle value of the front chuck, the actual rotation angle value of the rear chuck, the real-time output load torque value of the front chuck, and the real-time output load torque value of the rear chuck within a preset number of rotation cycles. S404. Determine whether the deviation between the actual rotation angle value and the theoretical rotation angle value of the front chuck within N consecutively collected rotation cycles meets the preset range; If so, proceed to step S405; If not, continue collecting and judging, and return to step S403; S405. Determine that the system has entered a steady-state operating state. Record the angle fluctuation amplitude and torque fluctuation amplitude in each rotation cycle under the steady-state operating state. Use the maximum value of the angle fluctuation amplitude and torque fluctuation amplitude as the angle reference value and torque reference value, respectively. S406. Raise the angle reference value by a first preset percentage as the angle warning threshold, and raise the angle reference value by a second preset percentage as the angle stop threshold; The torque reference value is increased by the first preset percentage as the torque warning threshold, and the torque reference value is increased by the second preset percentage as the torque shutdown threshold. The first preset percentage is less than the second preset percentage; In this embodiment, the above calibration and tuning method determines the threshold by measuring the steady-state fluctuation of the equipment under standard conditions, fully considering the individual differences in the mechanical characteristics of different equipment; using a first preset percentage (e.g., 20%) above the maximum steady-state fluctuation as the warning threshold and a second preset percentage (e.g., 40%) above as the shutdown threshold, it ensures that small fluctuations under normal operating conditions will not trigger false alarms, and also ensures that real eccentricity faults can be identified in a timely manner; in specific applications, the angle warning threshold can be tuned to ±0.3°, the angle shutdown threshold can be tuned to ±0.5°, the torque warning threshold can be tuned to 25% of the rated output torque, and the torque shutdown threshold can be tuned to 50% of the rated output torque; S5. The graded protection actuator obtains the pipe eccentricity fault judgment result and fault level identified by the synchronous controller, and executes the corresponding graded protection action according to the fault level. The specific steps of step S5 are as follows: S51. The graded protection actuator has a first-level warning threshold and a second-level shutdown threshold pre-stored in its internal storage; S52. The graded protection actuator obtains the pipe eccentricity fault judgment result and fault level output by the synchronous controller; If the fault level does not reach the first-level warning threshold, continue to execute data acquisition and synchronization control, and return to step S1; When the fault level reaches the first-level warning threshold but does not reach the second-level shutdown threshold, the graded protection actuator outputs a speed reduction protection signal to the front chuck drive module and the rear chuck drive module, controlling the front and rear chucks to reduce their speed to the preset speed reduction ratio. At the same time, the laser tube cutting machine's operation interface is triggered to issue a warning prompt. The synchronization controller continues to execute the synchronization control steps to continuously eliminate the dual-axis deviation, and then returns to step S1 to continue executing data acquisition and synchronization control. When the fault level reaches the second-level shutdown threshold, the graded protection actuator outputs an emergency stop protection signal to the front chuck drive module and the rear chuck drive module, blocking the power output signal of the two drive modules, causing the servo motor to stop outputting torque, and controlling the laser tube cutting machine to stop and lock the machine. In this embodiment, the graded protection actuator has a built-in two-level threshold protection mechanism. The first level is the warning threshold. When the detected value reaches the warning threshold, the system triggers an alarm on the operation interface and automatically reduces the speed to a preset reduction ratio (e.g., 50%-70% of the current speed). The synchronous controller continues to perform correction control to maintain production continuity to the maximum extent while ensuring safety and avoiding frequent shutdowns that affect processing efficiency. The second level is the extreme protection threshold. When the detected value reaches the shutdown threshold, it indicates that the pipe eccentricity has exceeded the equipment's tolerance range. The graded protection actuator immediately blocks the power output signal of the drive module, causing the servo motor to stop outputting torque and controlling the laser pipe cutting machine to stop and lock the machine, preventing the pipe from twisting and breaking and the equipment from being damaged.

[0027] In some embodiments, the following power-on pre-alignment step is included before step S1: S01. During the initial power-on phase of the equipment, the synchronous controller controls the front chuck and the rear chuck to perform automatic phase zeroing alignment, so that the phase of the front chuck and the rear chuck is zeroed. S02. The synchronous controller controls the front chuck drive module and the rear chuck drive module to apply preload torque and perform torque equalization preload alignment to eliminate assembly gaps and initial clamping deviations. By using the power-on pre-alignment function, the assembly gap and initial clamping deviation of the mechanical transmission chain are eliminated, providing a zero-position reference and pre-tightening state for subsequent high-precision synchronous control, and avoiding the impact and asynchrony caused by the existence of gaps at the moment of startup.

[0028] For example, in the standard dual-chuck cutting condition with identical parameters: The front and rear chuck drive pitches and reduction ratios are consistent. The tubing is 5mm thick steel pipe, a rigid material. After power-on, the system performs pre-alignment and then starts cutting. The synchronization controller uses cross-coupling closed-loop synchronization mode. The active chuck rotates normally following the processing commands, and the driven chuck follows the actual position of the drive shaft in real time. The angle deviation is calculated in real time and the speed compensation is generated through PI control. The driven shaft speed output is dynamically corrected. Simultaneously, the synchronous controller acquires the pipe wall thickness parameter (5mm), determines it to be a rigid pipe, and automatically selects a high-speed... , The gain operates in rigid synchronization mode, enabling rapid phase correction. The synchronization controller monitors in real time. and When the detected value reaches the warning threshold, a pop-up alarm will be triggered and the machine will slow down and continuously correct its deviation; when the detected value reaches the shutdown threshold, an emergency stop protection will be activated immediately to ensure cutting accuracy and pipe safety.

[0029] For example, in the case of flexible synchronous operation of thin-walled tubing: The pipe is a thin-walled round pipe with a wall thickness of 1.5mm, belonging to the category of flexible pipes. The system obtains the pipe wall thickness parameter (1.5mm), determines it to be a flexible pipe, and automatically switches to flexible synchronous mode: , The gain is reduced to the second gain value, and the jerk filter with accelerometer is enabled to adjust the velocity compensation. The changes are gradual, limiting the instantaneous torque required for correction. The synchronous controller also retains its ability to identify eccentricity faults and monitors them in real time. and The system determines whether a threshold is exceeded within N consecutive rotation cycles. This approach avoids excessive correction torque that could cause deformation of the thin-walled tube, while also ensuring both processing quality and safety.

[0030] For example, in non-standard operating conditions where the pitch of the front and rear chucks and the reduction ratio are inconsistent: The transmission parameters of the front and rear chucks of the equipment are different, for example, the pitch of the front chuck. =10mm, reduction ratio =2, rear chuck pitch =12mm, reduction ratio =2.5. After the system inputs different transmission parameters for the front and rear chucks, the synchronous controller calculates the dynamic electronic gear compensation coefficient. And based on the actual rotation angle of the front chuck Calculate the target following position of the driven axis Through this compensation mechanism, the rear chuck follows at an angle ratio 1.5 times that of the front chuck, ensuring that the actual rotational linear speed of the pipe is completely synchronized with the circumferential feed rate. This eliminates the fixed speed difference and cumulative position difference caused by inconsistent mechanical parameters, thus removing the structural false eccentricity alarm problem that traditional equipment cannot solve.

[0031] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0032] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A dual-chuck synchronous control and eccentricity detection and protection system for a laser tube cutting machine, characterized in that, It includes a front chuck drive module, a rear chuck drive module, a data acquisition module, a synchronization controller, and a graded protection actuator; The front chuck drive module is connected to the front chuck drive of the laser tube cutting machine, and the rear chuck drive module is connected to the rear chuck drive of the laser tube cutting machine. The data acquisition module is connected to both the front chuck drive module and the rear chuck drive module, and is used to acquire the actual rotation angle value and the real-time output load torque value of the front and rear chucks in real time. The synchronization controller is connected to the data acquisition module, the front chuck driver module, and the rear chuck driver module, and is configured as follows: The front chuck is the active follower of the command axis, and the rear chuck is the passive follower of the actual position axis. The actual rotation angle deviation between the two axes is calculated in real time and the speed output of the passive follower of the actual position axis is dynamically corrected to synchronize the physical phase of the two chucks. Based on the transmission parameters of the front and rear chucks, the target following position of the driven following shaft is dynamically compensated. Compare whether the actual rotation angle deviation between the front chuck and the rear chuck and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determine the pipe eccentricity fault and identify the pipe eccentricity fault level when they both exceed the preset thresholds. The graded protection actuator is connected to the synchronous controller and is used to perform graded protection actions according to the identified level of pipe eccentricity fault.

2. The dual-chuck synchronous control and eccentricity detection and protection system for laser tube cutting machines according to claim 1, characterized in that, The front chuck drive module includes a front chuck servo driver and a front chuck servo motor, and the rear chuck drive module includes a rear chuck servo driver and a rear chuck servo motor. The front chuck servo driver includes a first current regulator, a first speed regulator, a first position regulator, a first current sensor, and a first encoder interface. The output terminal of the first current regulator is connected to the three-phase winding terminal of the front chuck servo motor. The detection terminal of the first current sensor is set on the power supply line between the first current regulator and the front chuck servo motor. The feedback output terminal of the first current sensor is connected to the feedback input terminal of the first current regulator. The output terminal of the first speed regulator is connected to the command input terminal of the first current regulator. The output terminal of the first position regulator is connected to the command input terminal of the first speed regulator. The input terminal of the first encoder interface is connected to the encoder signal terminal mounted on the front chuck shaft. The position feedback output terminal of the first encoder interface is connected to the feedback input terminal of the first position regulator. The speed feedback output terminal of the first encoder interface is connected to the feedback input terminal of the first speed regulator. The rear chuck servo driver includes a second current regulator, a second speed regulator, a second position regulator, a second current sensor, and a second encoder interface. The output of the second current regulator is connected to the three-phase winding of the rear chuck servo motor. The detection end of the second current sensor is located on the power supply line between the second current regulator and the rear chuck servo motor. The feedback output of the second current sensor is connected to the feedback input of the second current regulator. The output of the second speed regulator is connected to the command input of the second current regulator. The output of the second position regulator is connected to the command input of the second speed regulator. The input of the second encoder interface is connected to the encoder signal end mounted on the rear chuck shaft. The position feedback output of the second encoder interface is connected to the feedback input of the second position regulator. The speed feedback output of the second encoder interface is connected to the feedback input of the second speed regulator.

3. The dual-chuck synchronous control and eccentricity detection and protection system for laser tube cutting machines according to claim 1, characterized in that, The data acquisition module includes a front chuck actual rotation angle sensor, a rear chuck actual rotation angle sensor, a front chuck output torque sensor, a rear chuck output torque sensor, and a data acquisition card; The actual rotation angle sensor of the front chuck is installed on the rotating shaft of the front chuck, and the actual rotation angle sensor of the rear chuck is installed on the rotating shaft of the rear chuck. The front chuck output torque sensor is set at the output end of the front chuck drive module, and the rear chuck output torque sensor is set at the output end of the rear chuck drive module. The data acquisition card is connected to the front chuck actual rotation angle sensor, the rear chuck actual rotation angle sensor, the front chuck output torque sensor, the rear chuck output torque sensor, and the synchronous controller.

4. A method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine, based on the system described in any one of claims 1-3, characterized in that, Includes the following steps: S1. The data acquisition module collects the actual rotation angle value of the front chuck and the rear chuck and the real-time output load torque value in real time, and outputs them to the synchronous controller. S2. The synchronous controller calculates the actual rotation angle deviation between the two axes based on the actual rotation angle values ​​of the front chuck and the rear chuck, with the front chuck as the active following command axis and the rear chuck as the driven following actual position axis. It then dynamically corrects the output speed of the driven axis accordingly, so that the physical phase of the two chucks is synchronized. S3. The synchronous controller acquires the transmission parameters of the front chuck and the rear chuck respectively, performs dynamic compensation on the target following position of the driven following actual position shaft, and uses the compensated target following position as the reference for correcting the speed of the driven following actual position shaft. S4. The synchronous controller calculates the real-time output load torque deviation between the front and rear chucks based on their respective actual rotation angle values ​​and real-time output load torque values, as well as the actual rotation angle deviation calculated by the synchronous controller. It compares whether the actual rotation angle deviation and the real-time output load torque deviation exceed their respective preset thresholds within N consecutive pipe rotation cycles, and determines the pipe eccentricity fault and identifies the pipe eccentricity fault level when both exceed the thresholds. S5. The graded protection actuator obtains the pipe eccentricity fault judgment result and fault level identified by the synchronous controller, and executes the corresponding graded protection action according to the fault level.

5. The method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine according to claim 4, characterized in that, The specific steps of step S2 are as follows: S21. The synchronous controller acquires the actual rotation angle value of the front chuck. and the actual rotation angle value of the rear chuck Calculate the actual rotation angle deviation between the front chuck and the rear chuck. ; S22. The synchronous controller will adjust the actual rotation angle deviation. The speed compensation amount for the driven axis following the actual position is generated through proportional-integral adjustment. ; in, For synchronous proportional gain, Synchronous integral gain; S23. The synchronous controller will automatically follow the original command speed of the actual position axis. With speed compensation amount Superimpose and calculate the final output speed of the driven shaft that follows the actual position. And send it to the rear chuck drive module to correct the speed output of the driven follower shaft at the actual position; The specific steps of step S3 are as follows: S31. The synchronous controller obtains the drive pitch of the front chuck. and reduction ratio and the drive pitch of the rear chuck and reduction ratio Calculate the dynamic electronic gear compensation coefficient ; S32. The synchronization controller adjusts the actual rotation angle of the front chuck. and dynamic electronic gear compensation coefficient Calculate the target following position of the driven following axis. And will follow the target position of the actual position axis. It serves as a following reference for correcting the rotational speed of the driven shaft based on its actual position.

6. The method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine according to claim 5, characterized in that, Step S3 also includes the following steps: S33. The synchronous controller acquires the wall thickness parameters of the pipe; When the pipe wall thickness parameter is greater than the preset wall thickness threshold, proceed to step S34; When the pipe wall thickness parameter is less than the preset wall thickness threshold, proceed to step S35; S34. The synchronous controller determines that the pipe is a rigid pipe and adjusts the synchronous proportional gain. and synchronous integral gain Set to the first gain value and execute rigid synchronization mode; In rigid synchronization mode, the synchronization controller uses a first gain value to measure the actual rotation angle deviation. The speed compensation amount for the driven axis following the actual position is generated through proportional-integral adjustment. and speed compensation amount The original command speed is directly superimposed on the driven axis following the actual position. To correct the output speed of the driven shaft; S35. The synchronous controller determines that the pipe is a flexible pipe and adjusts the synchronous proportional gain. and synchronous integral gain Set to the second gain value, which is less than the first gain value, and execute the flexible synchronization mode. In flexible synchronization mode, the synchronization controller uses a second gain value to calculate the actual rotation angle deviation. The speed compensation amount for the driven axis following the actual position is generated through proportional-integral adjustment. and in speed compensation amount The original command speed is superimposed on the driven axis following the actual position. Previously, the speed compensation amount Jerk filtering with jerk is applied to limit the instantaneous torque during correction.

7. The method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine according to claim 6, characterized in that, The specific steps of step S4 are as follows: S41. The synchronous controller acquires the real-time output load torque value of the front chuck from the data acquisition module. Real-time output of load torque value from rear chuck Calculate the real-time output load torque deviation between the front and rear chucks. ; S42. Synchronous controller for actual rotation angle deviation and real-time output load torque deviation A sliding window averaging filter is performed to eliminate instantaneous mechanical jitter interference; the sliding window averaging process involves taking the arithmetic mean of M consecutive sampled values ​​as the filtered output value at the current moment, where M≥3; S43. The synchronous controller compares the actual rotation angle deviation after filtering. and real-time output load torque deviation Whether the preset threshold is exceeded in each of N consecutive pipe rotation cycles, where N≥3; If so, determine the pipe eccentricity fault and identify the fault level, and output the determination result and fault level to the graded protection actuator. If not, determine to continue monitoring and return to step S41.

8. The method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine according to claim 7, characterized in that, In step S4, the calibration and tuning method for the preset threshold is as follows: S401. Select a standard pipe that meets the preset straightness requirements, and clamp the standard pipe onto the front chuck and the rear chuck according to the preset coaxiality requirements; S402. Control the front and rear chucks to run at a preset operating speed; S403. The data acquisition module acquires the actual rotation angle value of the front chuck, the actual rotation angle value of the rear chuck, the real-time output load torque value of the front chuck, and the real-time output load torque value of the rear chuck within a preset number of rotation cycles. S404. Determine whether the deviation between the actual rotation angle value and the theoretical rotation angle value of the front chuck within N consecutively collected rotation cycles meets the preset range; If so, proceed to step S405; If not, continue collecting and judging, and return to step S403; S405. Determine that the system has entered a steady-state operating state. Record the angle fluctuation amplitude and torque fluctuation amplitude in each rotation cycle under the steady-state operating state. Use the maximum value of the angle fluctuation amplitude and torque fluctuation amplitude as the angle reference value and torque reference value, respectively. S406. Raise the angle reference value by a first preset percentage as the angle warning threshold, and raise the angle reference value by a second preset percentage as the angle stop threshold; The torque reference value is increased by the first preset percentage as the torque warning threshold, and the torque reference value is increased by the second preset percentage as the torque shutdown threshold. The first preset percentage is less than the second preset percentage.

9. The method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine according to claim 4, characterized in that, The specific steps of step S5 are as follows: S51. The graded protection actuator has a first-level warning threshold and a second-level shutdown threshold pre-stored in its internal storage; S52. The graded protection actuator obtains the pipe eccentricity fault judgment result and fault level output by the synchronous controller; If the fault level does not reach the first-level warning threshold, continue to execute data acquisition and synchronization control, and return to step S1; When the fault level reaches the first-level warning threshold but does not reach the second-level shutdown threshold, the graded protection actuator outputs a speed reduction protection signal to the front chuck drive module and the rear chuck drive module, controlling the front chuck and the rear chuck to reduce their speed to the preset speed reduction ratio, and at the same time triggering the laser tube cutting machine's operation interface to issue a warning prompt. The synchronous controller continues to execute the synchronous control steps to continuously eliminate the dual-axis deviation, and then returns to step S1 to continue data acquisition and synchronous control. When the fault level reaches the second-level shutdown threshold, the graded protection actuator outputs an emergency stop protection signal to the front chuck drive module and the rear chuck drive module, blocking the power output signal of the two drive modules, causing the servo motor to stop outputting torque, and controlling the laser tube cutting machine to stop and lock.

10. The method for synchronous control and eccentricity detection and protection of a dual-chuck laser tube cutting machine according to claim 4, characterized in that, The following power-on pre-alignment steps are included before step S1: S01. During the initial power-on phase of the equipment, the synchronous controller controls the front chuck and the rear chuck to perform automatic phase zeroing alignment, so that the phase of the front chuck and the rear chuck is zeroed. S02. The synchronous controller controls the front chuck drive module and the rear chuck drive module to apply preload torque and perform torque equalization preload alignment to eliminate assembly gaps and initial clamping deviations.

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