Multi-station welding synchronization system and multi-station welding synchronization method

Abstract

The invention provides a multi-station welding synchronization system and a multi-station welding synchronization method. The multi-station welding synchronization system comprises a welding robot and a plurality of stations. The robot external shaft motor and the universal servo motor are arranged corresponding to the stations and are arranged on the two sides of the stations correspondingly, and the two separable parts of the workpiece to be welded are rotated correspondingly. The first controller is in communication connection with the welding robot and the robot external shaft motor. The second controller is in communication connection with the first controller and the universal servo motor, and the second controller is configured to receive the second control instruction, convert the second control instruction into a third control instruction suitable for the universal servo motor and send the third control instruction to the universal servo motor. By means of the arrangement, cooperative control over the multiple stations and the motors corresponding to the stations can be achieved only through one robot controller (namely the first controller), it is avoided that expensive robot controllers are additionally arranged, and the hardware cost and the maintenance cost of the whole system are greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of synchronous welding technology, specifically to a multi-station synchronous welding system and a multi-station synchronous welding method. Background Technology

[0002] In the industrial manufacturing sector, automated welding has become a key link in ensuring product quality and improving production efficiency. For large workpieces with complex structures and composed of multiple separable parts, the welding process usually involves the coordinated operation of a multi-axis positioner and a welding robot. A single workstation typically requires two external axis motors of the robot to clamp two parts of the workpiece respectively and coordinate their synchronous rotation to place the weld in the optimal welding position.

[0003] Currently, taking the mainstream control architecture for achieving synchronous welding in two workstations as an example, a centralized control architecture is often adopted: two robot controllers directly and simultaneously drive the welding robot and the four external axis motors corresponding to the two workstations. However, robot controllers often have limitations on the number of external axis motors they can control; for example, one robot controller can only control three external axis motors. In other words, when there are two workstations, two robot controllers are needed to drive four external axis motors simultaneously. Robot controllers are expensive, which significantly increases hardware and maintenance costs and hinders the expansion of the control architecture. Summary of the Invention

[0004] To address the above problems, this invention provides a multi-station welding synchronization system and a multi-station welding synchronization method to solve the problems of high hardware and maintenance costs in existing welding systems.

[0005] The first aspect of the present invention provides a multi-station welding synchronization system, including a welding robot, multiple stations, robot external axis motors, general servo motors, a first controller and a second controller.

[0006] Multiple workstations are used to clamp multiple workpieces. External axis motors and general-purpose servo motors of the robot are correspondingly positioned on either side of the workstations, rotating the two separable parts of the workpiece to be welded. A first controller is communicatively connected to the welding robot and its external axis motors, sending first control commands to the welding robot and second control commands to its external axis motors. A second controller is communicatively connected to both the first controller and the general-purpose servo motors. The second controller is configured to receive the second control commands from the first controller, convert them into third control commands suitable for the general-purpose servo motors, and send them to the general-purpose servo motors, thus coordinating the rotational control of the two separable parts of the workpiece to be welded between the robot's external axis motors and the general-purpose servo motors.

[0007] By adding a second controller for command coordination, a single robot controller (the first controller) can be used to coordinate the control of multiple workstations and their corresponding motors, avoiding the need for an additional, expensive robot controller. Directly applying the second and third control commands to the robot's external axis motors and general-purpose servo motors shortens the control chain and improves response speed. Compared to the traditional method of control cabinet-driven operation, this structure achieves high-precision synchronous coordination between the two motors, reducing errors caused by signal delay. Furthermore, the second controller can perform command conversion, allowing for the installation of a lower-cost general-purpose servo motor on one side of the workstation (e.g., the driven side), overcoming the power limitations of using external axis motors and further reducing the overall system hardware cost, facilitating system expansion. Simultaneously, the motion control of the robot's external axis motors and general-purpose servo motors, positioned on either side of the workpiece, is homogeneous, ensuring mutual cooperation and high coordination during workpiece rotation. This significantly improves welding accuracy and quality, and the electronic synchronization allows for rapid adaptation to the production needs of different workpieces, greatly reducing changeover costs and time.

[0008] Optionally, the multi-station welding synchronization system also includes multiple positioners, which are set up in correspondence with the workstations. The robot's external axis motor and general-purpose servo motor are located on both sides of the positioner.

[0009] By employing the above methods and installing corresponding positioners at each workstation, the positional limitations of the welding robot are overcome, allowing it to maintain a good welding posture and ensuring welding quality. Simultaneously, the rotation and tilting of the positioners correspond each part of the workpiece to be welded to the movement trajectory of the welding robot, thus expanding its working range.

[0010] Optionally, the second controller includes an electronic cam module, an interpolation module, and / or a coordinate transformation module for command conversion.

[0011] By using the above methods, multiple algorithm modules are set in the second controller, so that the motors on both sides can maintain synchronization through algorithm compensation even when the mechanical parameters or drive characteristics are different. This avoids the inability to achieve strict synchronization due to structural differences and effectively improves the system's compatibility and flexibility.

[0012] Optionally, the second controller also includes a synchronization compensation module for performing dynamic synchronization compensation of position, speed and phase based on the mechanical radius, gear ratio or configuration differences of the positioner.

[0013] By using the above methods, motion deviations can be continuously corrected under different load and speed conditions, preventing cumulative errors caused by mechanical differences, improving the stability of the welding process and the accuracy of long-term operation, and is especially suitable for welding irregularly shaped or large workpieces.

[0014] Optionally, the second controller also includes a fault detection unit for controlling the robot's external axis motors and general-purpose servo motors to safely stop in the event of a communication interruption or timeout.

[0015] The above methods ensure the safety of the equipment in the event of abnormal control links, prevent workpiece displacement or equipment damage, improve the overall system reliability and safety, and are suitable for continuous production needs.

[0016] Optionally, the multi-station welding synchronization system includes a calibration module for calibrating the zero point and phase of the positioner before production or during model changeover, and updating the synchronization parameters.

[0017] By using the above methods, it is ensured that the positioner at each workstation can quickly restore synchronization under different batches or different workpiece conditions, avoiding repeated manual adjustments and improving the flexibility and changeover efficiency of the production line.

[0018] A second aspect of the present invention provides a multi-station welding synchronization method, applied to the above-mentioned multi-station welding synchronization system, comprising: Step S1: The first controller sends a second control command to the robot's external axis motor to control one side of the workpiece to be welded. Step S2: The second controller acquires the second control instruction and converts it into a third control instruction suitable for general-purpose servo motors; Step S3: The second controller sends a third control command to the general-purpose servo motor so that the rotation control of the robot's external axis motor and the general-purpose servo motor of the two separable parts of the workpiece to be welded can be coordinated.

[0019] In this way, the first controller sends a second control command to the robot's external axis motor to drive the active side of the workpiece. The second controller obtains and converts the second control command into a third control command suitable for a general-purpose servo motor, and then sends it to the general-purpose servo motor on the driven side of the workpiece. This enables the robot's external axis motor and the general-purpose servo motor on both sides to rotate in coordination. This ensures the connection between the two controllers in the process, reduces manual intervention, and improves the level of welding automation and consistency.

[0020] Optionally, step S2 includes: performing electronic cam calculations, interpolation calculations, and / or coordinate transformations based on the second control command to convert the second control command into a third control command.

[0021] By using the above methods, smooth mapping can be achieved even when the driving characteristics of the two motors are different, thereby maintaining consistent action and effectively improving the adaptability and flexibility of the system.

[0022] Optionally, the second controller includes a discrete signal filtering module, and step S2 includes: the second controller filters the second control command through the discrete signal filtering module to smooth the second control command.

[0023] Through the above methods, filtering can make the changes in input commands more continuous and smooth, and reduce the impact and vibration of actuators such as general-purpose servo motors. Attached Figure Description

[0024] Figure 1 This is a first structural schematic diagram of a multi-station welding synchronization system according to an embodiment of the present invention.

[0025] Figure 2 This is a schematic diagram of the second structure of the multi-station welding synchronization system in an embodiment of the present invention.

[0026] Figure 3 This is an architectural diagram of a multi-station welding synchronization system according to an embodiment of the present invention.

[0027] Figure 4 This is a control flowchart of the second controller in the multi-station welding synchronization system according to an embodiment of the present invention.

[0028] Figure 5 This is a calibration flowchart of the multi-station welding synchronization system in an embodiment of the present invention.

[0029] Figure 6 This is a flowchart illustrating the operation of the multi-station welding synchronization system in an embodiment of the present invention.

[0030] Figure 7 This is a flowchart of a multi-station welding synchronization method according to an embodiment of the present invention.

[0031] Figure label: 100. Multi-station welding synchronous system; 1. Welding robot; 11. Laser generator; 2. First station; 21. First positioner; 3. Second station; 31. Second positioner; 4. External axis motor of robot; 5. General servo motor; 6. First controller; 7. Second controller. Detailed Implementation

[0032] 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.

[0033] <First Implementation Method> refer to Figure 1 , Figure 2 and Figure 3 The first embodiment of this invention provides a multi-station welding synchronization system 100, including a welding robot 1, multiple workstations, robot external axis motors 4 and general-purpose servo motors 5 correspondingly arranged on both sides of the workstations, a first controller 6 communicatively connected to the welding robot 1 and the robot external axis motors 4, and a second controller 7 communicatively connected to the first controller 6 and the general-purpose servo motors 5. A laser generator 11 may be provided at the end of the welding robot 1 facing the workpiece. The welding robot 1 uses the laser beam generated by the laser generator 11 as a heat source to achieve precise and efficient laser welding. Workstations are used to clamp the workpiece; for example, in this embodiment, there are two workstations, namely a first workstation 2 and a second workstation 3. The robot external axis motors 4 and general-purpose servo motors 5 respectively act on two separable parts of the workpiece. The first controller 6, i.e., the robot controller, may include a teach pendant and a robot control cabinet. The teach pendant is used for robot programming, path planning, and real-time monitoring, thereby realizing human-machine interaction. The first controller 6 is responsible for simultaneously issuing a first control command to the welding robot 1 and a second control command to the robot external axis motors 4. The second controller 7 receives the second control command from the first controller 6 and converts it into a third control command executable by the general-purpose servo motor 5, causing the robot's external axis motor 4 and the general-purpose servo motor 5 located on both sides of the workpiece to rotate in a coordinated manner. In some embodiments, the number of workstations can also be 3 or 4, and the present invention does not limit this.

[0034] By adding a second controller 7 for command coordination, the second controller 7 does not generate motion commands independently. Instead, it receives the second control commands sent by the first controller 6 to the robot's external axis motor 4, converts them in real time into third control commands suitable for the general-purpose servo motor 5, and then sends them out. This allows multiple workstations (such as...) to be controlled using only one robot controller (i.e., the first controller 6). Figure 1The first workstation 2 and the second workstation 3 shown are illustrated, along with the coordinated control of the motors corresponding to each workstation. Compared to existing technologies, such as a robot controller that can only control three external axis motors, this embodiment avoids the need for an expensive additional robot controller, effectively controlling the system's hardware and maintenance costs. By directly applying the second and third control commands to the robot's external axis motor 4 and the general-purpose servo motor 5, respectively, the control chain is shortened and the response speed is improved. Compared to the traditional method of driving solely through a control cabinet, this structure achieves high-precision synchronous coordination between the motors on both sides, reducing errors caused by signal delay. Furthermore, the second controller 6 can perform command conversion, allowing the lower-cost general-purpose servo motor 5 to be installed on the driven side of the workstation. This overcomes the power limitations of using the robot's external axis motor 4 and further reduces the overall system hardware cost, facilitating system expansion.

[0035] Meanwhile, the motion control of the robot's external axis motor 4 and the general-purpose servo motor 5, located on both sides of the workpiece, is based on the same principle, ensuring that their movements during workpiece rotation are coordinated and highly synchronized at the command level. This provides the welding robot 1 with a stable and precise weld trajectory. Compared to the synchronization errors caused by communication delays and load disturbances in traditional centralized control modes, this invention greatly improves welding accuracy and quality. Furthermore, by achieving synchronization through electronic control, it can quickly adapt to the production needs of different workpieces, significantly reducing changeover costs and time.

[0036] Specifically, the welding robot, the first station, and the second station can all be equipped with corresponding fixed seats (not shown) to provide reliable installation positions and facilitate the structural stability of each component during welding. The second controller 7 can be a programmable logic controller (PLC), a dedicated motion controller, or an embedded industrial computer with real-time processing capabilities. This embodiment does not limit the type of the second controller 7.

[0037] The following describes each part of the multi-station welding synchronization system in this embodiment.

[0038] <First positioner 21, Second positioner 31> refer to Figure 2 Each workstation is equipped with a positioner. For example, the first workstation 2 is equipped with a first positioner 21, and the second workstation 3 is equipped with a second positioner 31.

[0039] By employing the above methods and setting up corresponding positioners at each workstation, the positional limitations of welding robot 1 are overcome, allowing it to maintain a good welding posture and ensuring welding quality. Simultaneously, the rotation and tilting of the positioners correspond each part of the workpiece requiring welding to the movement trajectory of welding robot 1, thus expanding its working range.

[0040] In some embodiments, the first positioner 21 and the second positioner 31 may also be provided with clamps for clamping the two movable parts of the workpiece, fixing the workpiece as a whole, and ensuring the stability of the workpiece during the welding process.

[0041] <Robot external axis motor 4, general servo motor 5> Continue to refer to Figure 2 In the multi-station welding synchronization system 100, the robot's external axis motor 4 is driven by the second control command of the first controller 6, and the general-purpose servo motor 5 is driven by the third control command of the second controller 7. The number of robot external axis motors 4 and general-purpose servo motors 5 corresponds to the number of workstations. Furthermore, the robot external axis motor 4 is located on the active side of the workstation, and the general-purpose servo motor 5 is located on the driven side of the workstation.

[0042] In other words, the first controller 6 directly controls the robot's external axis motor 4, and the second controller 7 directly controls the general-purpose servo motor 5, which can balance the coordination of the entire system's commands while reducing the hardware cost of the entire system.

[0043] <Second Controller 7> Combination Figure 2 And refer to Figure 3 The second controller 7 includes an electronic cam module, an interpolation module, and / or a coordinate transformation module for command conversion. Each module is equipped with electronic cam commands, interpolation commands, and coordinate transformation commands.

[0044] With this configuration, multiple algorithm modules are set in the second controller 7, so that the robot's external axis motor 4 and general servo motor 5 on both sides of the workpiece can maintain synchronization through algorithm compensation even if the mechanism parameters or drive characteristics are different. This avoids the inability to achieve strict synchronization due to structural differences and effectively improves the system's compatibility and flexibility.

[0045] In this embodiment, the second controller 7 may further include a synchronization compensation module (not shown), capable of adjusting the synchronization compensation based on the positioner (e.g., ...). Figure 1 The mechanical radius, gear ratio, or configuration difference between the first positioner 21 and the second positioner 31 in the process is used to perform dynamic synchronous compensation of position, speed, and phase.

[0046] By using the above methods, motion deviations can be continuously corrected under different load and speed conditions, preventing cumulative errors caused by mechanical differences, improving the stability of the welding process and the accuracy of long-term operation, and is especially suitable for welding irregularly shaped or large workpieces.

[0047] Furthermore, the second controller 7 also includes a fault detection unit (not shown), which controls the robot's external axis motor 4 and general servo motor 5 to safely stop in the event of a communication interruption or timeout. This ensures the safety of the equipment in the event of abnormal control links, avoids workpiece displacement or equipment damage, and improves the overall reliability and safety of the multi-station welding synchronization system 100, making it suitable for continuous production needs.

[0048] Combination Figure 2 and refer to Figure 4 The control flow of the second controller 7 in the multi-station welding synchronous system 100 mainly includes several stages such as system initialization, alarm and communication detection, mode selection, operation control, and welding completion. After the system is powered on, it first enters the initialization stage. If the second controller 7 detects a system alarm, it needs to perform an alarm reset; if there is no alarm, it further performs communication detection, and enters the mode selection stage under normal communication conditions. The second controller 7 provides two operating modes: jog mode and synchronous mode.

[0049] The first method uses a jog mode: suitable for situations where the second controller 7 does not receive a synchronization signal. The user can individually start and stop the general-purpose servo motor 5 on the driven side of the workstation according to the set speed and acceleration parameters. When the jog button is pressed, the general-purpose servo motor 5 starts running; when the button is released, the general-purpose servo motor 5 stops running, suitable for single-axis debugging and simple operation.

[0050] The second method is a synchronous mode: this is suitable when the second controller 7 has received a synchronization signal. In this mode, the multi-station welding synchronization system 100 first sets the parameters required for synchronous operation and achieves coordination between multiple stations through position control. After pressing the synchronization button, the second controller 7 receives the second control command (including axis position command) from the first controller 6 and processes it using an algorithm to generate accurate linear / interpolation position commands, i.e., the third control command. This command is then transmitted to the general-purpose servo motor 5 via a high-speed MECHATROLINK network, enabling coordinated drive of multiple motors and ensuring the synchronization of multi-station welding. Once the welding action is completed, the multi-station welding synchronization system 100 can enter the motor stop and power-off phase.

[0051] This control process enables single-machine debugging and flexible operation in jog mode, and precise coordinated welding between motors in multi-station mode, balancing the convenience of system debugging with the efficiency and consistency of welding operations. Meanwhile, the multi-station welding synchronization system 100 enhances operational safety and reliability through alarm and communication detection mechanisms, ensuring stable and accurate control in multi-station welding scenarios.

[0052] <First Controller 6> refer to Figure 2The communication methods of the first controller 6 and the second controller 7 in this embodiment will be described in detail. The communication between the first controller 6 and the second controller 7, between the first controller 6 and the robot's external axis motor 4, and between the second controller 7 and the general-purpose servo motor 5 can all be achieved using industrial Ethernet protocols, such as MECHATROLINK (as used in this embodiment), EtherCAT, Profinet, Modbus TCP, or fieldbuses like CANopen.

[0053] <Calibration Module> In this embodiment, the multi-station welding synchronization system 100 may further include a calibration module (not shown) for calibrating each positioner before production or during model changeover (e.g., Figure 1 The zero point and phase of the first positioner 21 and the second positioner 31 are determined, and the synchronization parameters are updated.

[0054] By using the above methods, it is ensured that the positioners on both sides can quickly restore synchronization under different batches or different workpiece conditions, avoiding repeated manual adjustments and improving the flexibility and changeover efficiency of the production line.

[0055] Combination Figure 2 and refer to Figure 5 Furthermore, the calibration process for the multi-station welding synchronization system 100 in this embodiment is as follows.

[0056] First, when the multi-station welding synchronization system 100 is in jog mode, the welding robot 1 is set to manual operation mode so that the user can make precise adjustments to the welding robot 1 and the external axis controlled by the robot's external axis motor 4 through manual control (e.g., through a teach pendant).

[0057] Subsequently, a five-point tool center point (TCP) calibration is performed. Specifically, by selecting five known location points in space and having the end effector of welding robot 1 sequentially reach these points, the actual center point coordinates and attitude parameters of the welding tool on welding robot 1 are calculated to ensure the accuracy of the welding path.

[0058] After TCP calibration is completed, the external axes of the welding robot 1 body are moved to the preset reference calibration position, and the position is recorded and calibrated to establish the spatial correspondence between the coordinate system of the welding robot 1 and the external axes of the body. Furthermore, the general external axes are also moved to their reference calibration positions and calibrated, thereby ensuring that a unified reference coordinate system is formed between each external axis and the welding robot 1 body.

[0059] After the external axis reference position is calibrated, the multi-station welding synchronization system 100 switches to synchronization mode and activates the synchronization signal. Activating the synchronization signal prepares the welding robot 1 body and the external axes for coordinated operation. Subsequently, the user adjusts the synchronization rate parameter according to actual production needs to determine the proportional relationship of motion between the welding robot 1 body and each external axis, thereby achieving precise coordination between multiple stations.

[0060] After completing the above calibration process, a consistent coordinate reference and motion relationship are formed between the welding robot 1 body and the external axis, thereby ensuring that the welding actions of each station remain synchronized and stable during the multi-station welding operation, improving welding quality and overall production efficiency.

[0061] Combination Figure 1 and Figure 2 and refer to Figure 6 The operation flow of the multi-station welding synchronization system 100 in this embodiment will be described below. Taking a system with two stations (i.e., a first station 2 and a second station 3) as an example.

[0062] First, when the multi-station welding synchronization system 100 is in jogging mode, the user can manually start the welding robot 1 to switch the welding robot 1 to automatic operation mode.

[0063] Next, it is determined whether the welding robot 1 body and external axis are at the origin position. If it is detected that it is not at the origin position, a one-key return operation is executed to move the welding robot 1 and external axis to their respective initial reference points, ensuring that each station is in a uniform starting state.

[0064] After confirming the origin, enable the robot's external axis motor 4 and general-purpose servo motor 5 to enable them to operate under controlled conditions. Then, activate the synchronization signal to establish a synchronous control relationship between the robot body and the external axis.

[0065] After the synchronous control relationship is established, the system enters the workstation standby stage. When the system detects that each workstation has issued a signal indicating it is in position, the multi-workstation welding synchronization system 100 sequentially triggers the welding operation of the corresponding workstation. For example, when the first workstation 2 issues a signal indicating it is in position, the welding of the workpiece at the first workstation 2 is executed; when the second workstation 3 issues a signal indicating it is in position, the welding of the workpiece at the second workstation 3 is executed, and so on.

[0066] Throughout the welding process, communication and servo status are continuously monitored. If the detection results are normal, the welding process continues; if an anomaly is detected, an alarm is immediately issued to remind the user to troubleshoot and handle the problem.

[0067] Once the welding operations at all workstations are completed, the current operation process ends, thereby achieving automation and synchronization of multi-workstation welding.

[0068] <Second Implementation Method> Combination Figure 1 and Figure 2 and refer to Figure 7 The second embodiment of the present invention provides a multi-station welding synchronization method, applied to the above-mentioned multi-station welding synchronization system 100, comprising: Step S1: The first controller 6 sends a second control command to the robot's external axis motor 4 so that the robot's external axis motor 4 controls one side of the workpiece to be welded; Step S2: The second controller 7 acquires the second control instruction and converts it into a third control instruction suitable for the general-purpose servo motor 5; Step S3: The second controller 7 sends a third control command to the general-purpose servo motor 5 so that the rotation control of the two separable parts of the workpiece to be welded by the robot's external axis motor 4 and the general-purpose servo motor 5 can be coordinated.

[0069] In this way, the first controller 6 sends a second control command to the robot's external axis motor 4 to drive the active side of the workpiece. The second controller 7 obtains and converts the second control command into a third control command applicable to the general-purpose servo motor 5, and then sends it to the general-purpose servo motor 5 on the driven side of the workpiece, so that the robot's external axis motor 4 and the general-purpose servo motor 5 on both sides can rotate in coordination. This ensures the connection between the first controller 6 and the second controller 7 in the process, reduces manual intervention, and improves the level of welding automation and consistency.

[0070] Combination Figure 7 and refer to Figure 2 Step S1 includes: the first controller 6 sends a second control command to the robot external axis motor 4 on the active side of each workstation. The second control command includes a first position command and a first speed command. Step S3 includes: the second controller 7 sends a third control command to the general servo motor 5 on the driven side of each workstation. The third control command includes a second position command, a second speed command, and a phase command.

[0071] In other words, by clearly distinguishing the control dimensions of the commands on both sides, namely the second control command and the third control command, and by introducing phase control, the movements on both sides are kept highly consistent in time and space, thereby ensuring high precision in the welding of complex workpieces.

[0072] Combination Figure 2 and Figure 7 and refer to Figure 4Step S2 includes: performing electronic cam calculations, interpolation calculations, and / or coordinate transformations based on the second control command to convert the second control command into a third control command. This configuration enables smooth mapping even when the drive characteristics of the two motors differ, thus maintaining consistent action and effectively improving the system's adaptability and flexibility.

[0073] Furthermore, the second controller 7 includes a discrete signal filtering module (not shown). Step S2 includes: the second controller 7 filters the second control command through the discrete signal filtering module to smooth the second control command and facilitate its subsequent conversion into a third control command. Through this method, the filtering process makes the changes in the input command more continuous and smooth, reducing the impact and vibration on the robot's external axis motor 4 and general-purpose servo motor 5, and other actuators.

[0074] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-station welding synchronous system, characterized in that, include: Welding robots; Multiple workstations are used to clamp multiple workpieces; The robot's external axis motor and general-purpose servo motor are arranged corresponding to the workstation and respectively on both sides of the workstation, and rotate the two separable parts of the workpiece to be welded respectively. The first controller is communicatively connected to the welding robot and the external axis motor of the robot, respectively, and is used to send a first control command to the welding robot and a second control command to the external axis motor of the robot. The second controller is communicatively connected to both the first controller and the general-purpose servo motor. The second controller is configured to receive the second control command from the first controller, convert it into a third control command suitable for the general-purpose servo motor, and send it to the general-purpose servo motor so that the rotation control of the robot external axis motor and the general-purpose servo motor of the two separable parts of the workpiece to be welded cooperates with each other.

2. The multi-station welding synchronization system according to claim 1, characterized in that, Also includes: Multiple positioners are set up corresponding to the workstation, and the robot's external axis motor and the general servo motor are located on both sides of the positioner.

3. The multi-station welding synchronous system according to claim 1, characterized in that, The second controller includes an electronic cam module for command conversion, an interpolation module, and / or a coordinate transformation module.

4. The multi-station welding synchronous system according to claim 2, characterized in that, The second controller also includes a synchronization compensation module, used to perform dynamic synchronization compensation of position, speed and phase based on the mechanical radius, gear ratio or configuration differences of the positioner.

5. The multi-station welding synchronous system according to claim 1, characterized in that, The second controller also includes a fault detection unit for controlling the robot's external axis motor and the general-purpose servo motor to safely stop in the event of a communication interruption or timeout.

6. The multi-station welding synchronous system according to claim 2, characterized in that, The multi-station welding synchronization system includes a calibration module for calibrating the zero point and phase of the positioner before production or during model changeover, and updating the synchronization parameters.

7. A method for simultaneous multi-station welding, applied to the simultaneous multi-station welding system as described in any one of claims 1-6, characterized in that, include: Step S1: The first controller sends a second control command to the robot's external axis motor to control one side of the workpiece to be welded; Step S2: The second controller acquires the second control instruction and converts it into a third control instruction suitable for a general-purpose servo motor; Step S3: The second controller sends the third control command to the general-purpose servo motor so that the rotation control of the robot's external axis motor and the general-purpose servo motor of the two separable parts of the workpiece to be welded can be coordinated.

8. The multi-station welding synchronization method according to claim 7, characterized in that, Step S2 includes: Based on the second control command, electronic cam calculation, interpolation calculation and / or coordinate transformation are performed to convert the second control command into a third control command.

9. The multi-station welding synchronization method according to claim 7, characterized in that, The second controller includes a discrete signal filtering processing module, and step S2 further includes: The second controller filters the second control command through the discrete signal filtering module to smooth the second control command.

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