Laser processing galvanometer and shaft control switching method and system

Abstract

The application discloses a laser processing galvanometer and shaft control switching method and system, relates to the field of laser processing control, and comprises the following steps: issuing a holding angle instruction to the galvanometer during the execution of a transfer motion of a motion shaft to make the galvanometer in a holding state; collecting an actual angle output by a position detector of the galvanometer during the holding state, and recording a deviation of the actual angle from the holding angle as a holding deviation sequence; extracting a maximum value of the absolute value of the deviation according to a preset time window to obtain a residual vibration envelope sequence; selecting a target attenuation template matched with the transfer motion from an attenuation template library, aligning the target attenuation template according to a deceleration start time of the motion shaft to determine a predicted stable time, and issuing a light preparation instruction to a laser in advance; and when the residual vibration envelope sequence enters an allowed amplitude band, switching the galvanometer to a scanning state, and executing scanning processing on a current processing partition. The application solves the problems of unperceivable residual vibration of a scanning head during switching of the galvanometer and the shaft control, dependence on a fixed waiting time, waste of a beat, and splicing vibration patterns.

Description

Technical Field

[0001] This application relates to the field of laser processing control technology, and more specifically, to a method and system for switching between laser processing galvanometers and axis control. Background Technology

[0002] Large-format laser processing equipment, such as laser cutting machines, laser welding workstations, and metal 3D printing equipment, generally employs both galvanometers and CNC motion axes as actuators. The galvanometer deflects the laser beam using high-speed oscillating reflectors, offering fast scanning speeds and high positioning accuracy. However, its field of view is limited, covering only a finite area per scan. The CNC motion axes have a large travel range, allowing movement of the workpiece or scanning head across the entire workpiece area, but they suffer from high inertia and slow response. Therefore, when processing workpieces exceeding the galvanometer's field of view, the graphic to be processed is typically divided into multiple processing zones. After the galvanometer completes scanning one zone, the motion axes transfer the workpiece or scanning head to the next zone. The quality of the transition between these two actuators directly determines the overall processing cycle time and the processing quality at the zone joints.

[0003] Existing technologies have already yielded improved solutions for partitioned splicing. For example, patent CN103639593A, entitled "Method and System for Seamless Splicing of Large Format Graphics in Laser Processing," discloses a scheme that divides the image to be processed into multiple splicing areas according to the scanning range of the galvanometer and processes them one by one, ensuring that the current processing area is within the optimal scanning range of the galvanometer. Another example is patent CN109702319A, entitled "Online Splicing Method and System for Large Format Laser Processing," which points out that this type of splicing relies entirely on the movement accuracy of the motion platform. Therefore, it uses a coaxial measuring unit to acquire images of the area to be processed, compares the theoretical bounding box with the actual bounding box to obtain the splicing translation and deflection angle, and adjusts the position of the sub-block graphics online accordingly.

[0004] However, the aforementioned existing technologies mainly address the issues of how to divide the partitions and how to correct the splicing positions, without considering the structural residual vibration of the scanning head at the moment the motion axis stops. When the motion axis stops abruptly, the inertial impact will excite the structural residual vibration of the overhanging scanning head. The grating ruler used by the equipment to determine positioning is mounted on the machine base and can only reflect the platform's position, unable to sense the vibration at the end of the scanning head. This results in the scanning head often still vibrating when the positioning signal is issued. If the galvanometer immediately begins scanning at this point, the residual vibration will be reflected onto the machining trajectory, forming vibration marks at the beginning of the partition and exacerbating joint misalignment.

[0005] Because residual vibration is undetectable, existing equipment typically sets a fixed waiting time after the arrival signal. However, determining the optimal value for this time presents a dilemma. If the value is too long, redundant waiting occurs with each switchover; large-format workpieces often involve hundreds or thousands of partition switches, resulting in substantial lost productivity due to accumulated waiting. If the value is too short, processing begins before the scanning head has fully stabilized, leading to vibration marks and misaligned seams at the beginning of the partition. These defects are only detected during post-processing inspection, by which time all materials and time have already been invested. In practice, the waiting time is often conservatively set based on the worst-case scenario, resulting in most switchovers incurring a time cost exceeding the actual requirements.

[0006] Furthermore, adding an accelerometer to the scanning head to detect vibration would increase hardware costs and wiring channels, requiring recalibration of the entire signal link, which is costly for mass production equipment. Therefore, a new method for switching between the galvanometer and axis control is needed, enabling the equipment to sense the residual vibration state of the scanning head in real time without adding any hardware, and to determine the start-up timing for each switch accordingly. This avoids both the production capacity loss due to redundant waiting and the processing defects caused by starting with vibration. Summary of the Invention

[0007] The technical problem to be solved by this application is to provide a method and system for switching laser processing galvanometers and axis control, which is used to sense the residual vibration state of the scanning head in real time without adding hardware, so that the switching start time is determined by the measured vibration state, and to complete the measurement and correction of the partition splicing deviation before start-up.

[0008] To achieve the above technical objectives, this application employs the following technical means: A method for switching between a laser processing galvanometer and axis control is applied to the laser processing process of an intelligent welding system or metal cutting and welding equipment. The laser processing process involves the galvanometer scanning each processing zone and the motion axis performing transfer motion between adjacent processing zones. The method includes: during the transfer motion of the motion axis, issuing a holding angle command to the galvanometer to keep the galvanometer in a holding state. The actual angle output by the position detector of the galvanometer is collected during the holding state, and the deviation between the actual angle and the holding angle indicated by the holding angle command is recorded as a holding deviation sequence; The maximum absolute value of the deviation is extracted window by window from the holding deviation sequence according to the preset time window to obtain the residual vibration envelope sequence; Select a target attenuation template that matches the transfer motion from a pre-built attenuation template library, align the residual vibration envelope sequence with the target attenuation template at the deceleration start time of the motion axis, and determine the time when the envelope in the target attenuation template enters the preset allowable amplitude band as the predicted stable time. The light preparation command is sent to the laser ahead of the predicted stabilization time according to the preset light emission preparation time. When the residual vibration envelope sequence enters the allowed amplitude band, the galvanometer is controlled to switch from the holding state to the scanning state, and scanning processing is performed on the current processing partition, which is the processing partition reached by the transfer motion.

[0009] Optionally, the attenuation template library is constructed as follows: In the historical transfer motion, taking the deceleration start time of the motion axis as the time starting point, the holding deviation sequence corresponding to each historical transfer motion is collected and the corresponding residual vibration envelope sequence is extracted as the historical envelope attenuation curve; each historical envelope attenuation curve is classified according to the interval to which the travel length of the transfer motion belongs and the interval to which the maximum speed belongs, and the time-by-time mean curve of each historical envelope attenuation curve under the same category is used as the attenuation template of that category, and the mean of the time from the time starting point to the time to enter the allowable amplitude band of each historical envelope attenuation curve under that category is used as the arrival time label of that category; the method for selecting the target attenuation template is as follows: determine the interval to which the travel length of the transfer motion belongs and the interval to which the maximum speed belongs, and determine the attenuation template of the corresponding category as the target attenuation template.

[0010] Optionally, the galvanometer includes a first scanning axis and a second scanning axis, respectively acquiring the hold deviation sequence of the first scanning axis and the hold deviation sequence of the second scanning axis, and respectively extracting the residual envelope sequence of the first scanning axis and the residual envelope sequence of the second scanning axis; when both the residual envelope sequence of the first scanning axis and the residual envelope sequence of the second scanning axis enter the allowable amplitude band, the galvanometer is controlled to switch from the hold state to the scanning state; the predicted stabilization time is the later of the predicted stabilization time corresponding to the first scanning axis and the predicted stabilization time corresponding to the second scanning axis.

[0011] Optionally, the allowed amplitude band includes a processing-level amplitude threshold and a measurement-level amplitude threshold, wherein the measurement-level amplitude threshold is smaller than the processing-level amplitude threshold; a processing ready signal is generated when the residual vibration envelope sequence enters the amplitude band defined by the processing-level amplitude threshold, and a measurement ready signal is generated when the residual vibration envelope sequence enters the amplitude band defined by the measurement-level amplitude threshold; the generation of the processing ready signal is used as a trigger condition for controlling the galvanometer to switch from the holding state to the scanning state.

[0012] Optionally, if the residual vibration envelope sequence still fails to enter the allowable amplitude band after a preset timeout period from the predicted stabilization time, the current switch is determined to be an abnormal handover event. The motion axis is then controlled to re-execute the positioning motion according to the positioning target of the current processing zone, and the acquisition of the retention deviation sequence, the extraction of the residual vibration envelope sequence, and the determination of the predicted stabilization time are re-executed.

[0013] Optionally, in response to the measurement ready signal, before controlling the galvanometer to switch from the holding state to the scanning state, the laser is controlled to emit light at a detection power less than the processing power used in the scanning process; the galvanometer is controlled to drive the laser spot to move along the detection path, the detection path intersecting with the processed trajectory in the adjacent processed section; a coaxial photodetector collects the reflected light intensity signal from the workpiece surface during the detection path, forming a detection signal sequence; the amplitude of the detection signal sequence corresponding to the section in the detection path that does not intersect with the processed trajectory is... The mean value is determined as the baseline amplitude. A continuous segment in the detection signal sequence where the difference between the amplitude and the baseline amplitude exceeds a preset abrupt change threshold is identified. The midpoint of this continuous segment is determined as a characteristic abrupt change point. The difference between the spot position calculated from the actual angle of the galvanometer at the corresponding moment of the characteristic abrupt change point and the theoretical position of the processed trajectory in the coordinate system of the current processing partition is determined as the splicing deviation. The splicing deviation is used to correct the coordinates of the processed graphic in the current processing partition. After correction, the galvanometer is controlled to switch from the holding state to the scanning state.

[0014] Optionally, the detection stroke includes a first detection stroke and a second detection stroke. The first detection stroke intersects with the processed trajectory extending along a first direction, and the second detection stroke intersects with the processed trajectory extending along a second direction. The first direction and the second direction are perpendicular to each other. The splicing deviation determined by the first detection stroke is used as the translation correction amount of the processed graphic coordinates of the current processing partition in the direction perpendicular to the first direction, and the splicing deviation determined by the second detection stroke is used as the translation correction amount of the processed graphic coordinates of the current processing partition in the direction perpendicular to the second direction. When the time width of the continuous segment corresponding to any detection stroke exceeds a preset width threshold, the detection stroke is determined to be invalid, and the acquisition of the deviation sequence and the detection stroke are re-executed.

[0015] Optionally, after each detection journey is completed, the partition position of the current processing partition, the switching time of the galvanometer to the scanning state, and the stitching deviation are stored as a handover record in the handover archive. Using the partition position and switching time of each handover record in the handover archive as input and the stitching deviation of each handover record as output, an online machine learning regression model is trained to obtain a deformation field model. For processing partitions that have not yet been processed, the partition position of the processing partition and the expected switching time determined according to the processing schedule are input into the deformation field model to obtain the predicted stitching deviation. Before the detection journey of the processing partition is executed, the processing graphic coordinates of the processing partition are pre-corrected according to the predicted stitching deviation. The stitching deviation obtained from the detection journey of the processing partition is used to further correct the processing graphic coordinates of the processing partition based on the pre-correction.

[0016] Optionally, the online training method of the deformation field model is as follows: a training sample set is formed by the first preset number of recently stored handover records in the handover archive, and an incremental update is performed on the machine learning regression model using the training sample set after each new handover record is added; it also includes: the attenuation template library stores attenuation templates according to the interval of the travel length of the transfer motion and the interval of the maximum speed, and the target attenuation template is provided with an arrival time label, the arrival time label being the average of the duration from the start of deceleration to the entry into the allowable amplitude band of each historical envelope attenuation curve that constructs the attenuation template; the duration from the start of deceleration to the entry into the allowable amplitude band of the residual vibration envelope sequence is recorded as the measured arrival time, and the difference between the measured arrival time and the arrival time label is recorded as the template deviation sample; when the average of the second preset number of template deviation samples in the same category exceeds the preset update threshold, the time-by-time average curve is recalculated using each recently collected historical envelope attenuation curve in the same category, and the attenuation template of the category is updated.

[0017] This application also discloses a laser processing galvanometer and axis control switching system for implementing the method described in this application, including a galvanometer, a motion axis, a laser, and a switching controller; The motion axis is used to perform transfer motion between adjacent processing zones; The galvanometer is equipped with a position detector. The galvanometer is used to perform scanning processing on each processing zone and to remain in a holding state according to the holding angle command during the transfer motion of the motion axis. The switching controller includes a bias acquisition module, an envelope extraction module, an attenuation template library, a stability prediction module, and a switching trigger module; The holding deviation acquisition module is used to acquire the actual angle output by the position detector during the holding state, and record the deviation between the actual angle and the holding angle indicated by the holding angle command as a holding deviation sequence; The envelope extraction module is used to extract the maximum value of the absolute value of the deviation from the holding deviation sequence window by window according to a preset time window, so as to obtain the residual vibration envelope sequence. The attenuation template library is used to classify and store attenuation templates according to the range of travel length and the range of maximum speed of the transfer motion; The stability prediction module is used to select a target attenuation template that matches the transfer motion from the attenuation template library, align the residual vibration envelope sequence with the target attenuation template according to the deceleration start time of the motion axis, determine the time when the envelope in the target attenuation template enters the preset allowable amplitude band as the predicted stability time, and send a light preparation command to the laser ahead of the predicted stability time according to the preset light preparation time. The switching trigger module is used to control the galvanometer to switch from the holding state to the scanning state when the residual vibration envelope sequence enters the allowed amplitude band, and to perform scanning processing on the current processing partition, wherein the current processing partition is the processing partition reached by the transfer motion.

[0018] The beneficial effects of this application are as follows: This application solves the problem of undetectable scanning head vibration state by using the galvanometer holding deviation during the switching wait period as a residual vibration observation signal, without adding any hardware. Specifically, the galvanometer rotor, along with the reflecting mirror, is suspended at the commanded angle by a servo system. The residual vibration of the base is coupled to the mirror through the mounting structure. The holding deviation sequence recorded by the servo to maintain the angle therefore contains this vibration information and is taken from the position closest to the beam exit. Existing equipment discards this signal entirely during the switching wait period. This application extracts the residual vibration envelope sequence from it, which is equivalent to obtaining a vibration observation channel using the equipment's built-in components, eliminating the cost of adding sensors and calibrating signal links. Based on this, this application utilizes the highly similarity of the residual vibration attenuation process of transfer motions with similar stroke and speed to construct an attenuation template library classified by stroke length and maximum speed. The measured residual vibration envelope sequence is aligned with the target attenuation template, predicting the stabilization time in advance, allowing beam exit preparation and vibration attenuation to proceed in parallel, and starting scanning immediately when the envelope actually enters the allowable amplitude band. In this way, the waiting time for each switch is compressed to the minimum physically necessary limit, and the time saved by hundreds or thousands of switches is directly converted into production capacity. At the same time, the laser is only turned on after the measured envelope enters the allowable amplitude band, and when the prediction fails, it is repositioned according to the abnormal handover event. The increase in production capacity does not come at the expense of processing quality.

[0019] Meanwhile, this application utilizes the quiet transition window during the handover process to measure splicing deviations online, advancing the detection of seam misalignment from after processing completion to before the start of processing in this section. Specifically, the laser emits light at a detection power lower than the processing power, and the light spot scans along the detection path across the processed trajectory in the adjacent processed section. The reflected light intensity collected by the coaxial photodetector shows a characteristic abrupt change at the old trajectory. The difference between the abrupt change location and the theoretical location is the actual splicing deviation of this section relative to the adjacent area. This measurement uses the existing processing results on the workpiece as a benchmark, does not require an additional camera, and is not affected by smoke or dust. The measured splicing deviation is directly used to correct the processing graphic coordinates of the current processing section, thereby eliminating seam misalignment before defects occur. In addition, the abnormal widening of the abrupt change section indicates that the scanning head has not truly stopped, so the stopping determination can be verified in reverse; the measurement level amplitude threshold is lower than the processing level amplitude threshold, allowing the measurement to be performed in a quieter state.

[0020] This application also enables continuous self-calibration of equipment during batch processing through a handover archive and online regression modeling. The gradual deformation of the workpiece under clamping stress and processing heat input is not random, but follows a continuous pattern with position and time. Therefore, this application stores the splicing deviation and switching time of each handover in the handover archive, trains the machine learning regression model online to obtain the deformation field model, and performs pre-correction on the unprocessed partitions according to the predicted splicing deviation before starting work. The detection stage only needs to handle the remaining deviation. At the same time, it continuously records the difference between the measured arrival time and the arrival time label. When the difference forms a trend, it automatically updates the attenuation template library, so that the stopping prediction is not inaccurate due to equipment aging or changes in operating conditions.

[0021] In summary, this application determines the switching timing based on measured vibration conditions, corrects splicing deviations before commencement of work, automatically updates model parameters according to equipment status, and provides measurement data support for each decision. Therefore, this application can simultaneously improve the cycle time and splicing accuracy of large-format laser processing, making it particularly suitable for step-by-step splicing processing scenarios with frequent zone switching and high seam quality requirements. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the laser processing galvanometer and axis control switching system provided in the embodiments of this application; Figure 2 A schematic flowchart illustrating the laser processing galvanometer and axis control switching method provided in this application embodiment; Figure 3 This is a schematic diagram illustrating the alignment and switching timing of the residual vibration envelope sequence with the target attenuation template provided in the embodiments of this application; Figure 4 A schematic diagram illustrating the measurement of probe travel and splicing deviation provided in an embodiment of this application; Figure 5 A schematic diagram of the detection signal sequence provided in an embodiment of this application; Figure 6 This is a schematic diagram of the structure of the switching controller provided in an embodiment of this application; Figure 7 This is a schematic diagram illustrating the process of online updating of the handover archive and deformation field model provided in the embodiments of this application.

[0023] Figure labeling: 10-Galvanometer; 11-Position detector; 12-Field mirror; 20-Motion axis; 30-Laser; 40-Switching controller; 41-Maintaining deviation acquisition module; 42-Envelope extraction module; 43-Attenuation template library; 44-Stability prediction module; 45-Switching trigger module; 46-Transfer archive; 47-Deformation field model; 50-Workpiece; 51-Adjacent processed zones; 52-Current processing zone. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0025] The use of terms like "first," "second," etc., in the embodiments of this application is only for distinguishing similar objects and does not represent a chronological order or degree of importance. The specific parameter values ​​given in the embodiments are examples used to help understand the scheme; they can be adjusted according to equipment conditions and process requirements during actual implementation.

[0026] Figure 1 This is a schematic diagram of the structure of the laser processing galvanometer and axis control switching system provided in an embodiment of this application. (Refer to...) Figure 1 The laser output from laser 30 is introduced into the scanning head via optical fiber. Inside the scanning head, it is deflected sequentially by two mirrors of galvanometer 10, and then focused onto the surface of workpiece 50 by field lens 12. Galvanometer 10 typically has two scanning axes, each driving a mirror arranged at a 45-degree angle. A position detector 11 is mounted at the end of each scanning axis to output the actual angle of the mirror in real time. The position detector 11... Figure 1 The actual angle output from the second scanning axis is transmitted back to the switching controller 40 via a signal line.

[0027] The motion axis 20 carries the workpiece 50 or a scanning head containing the galvanometer 10 and field lens 12, performing large-stroke movement across the entire processing area. The switching controller 40 is connected to the driver of the galvanometer 10, the axis control unit of the motion axis 20, and the laser 30, respectively, and is responsible for coordinating the timing of their actions during zone switching. This system is designed for intelligent welding systems and metal cutting and welding equipment. The workpiece 50 is a metal sheet or component to be welded or cut; the following discussion will use this scenario as an example.

[0028] When the graphic to be processed exceeds the scanning field of view of the galvanometer 10, the entire area is divided into multiple processing zones. After the galvanometer 10 completes the scanning of one zone, the motion axis 20 transfers the workpiece 50 or the scanning head to the next zone. This movement is called the transfer motion, and the processing zone reached by the transfer motion is the current processing zone 52. Figure 1 The diagram also shows the adjacent processed zone 51 adjacent to the current processing zone 52, which will be used as the reference for the splicing deviation measurement in the following text. Misalignment of the zone joints is directly manifested as weld overlap misalignment in welding scenarios and as misalignment at the contour joint in cutting scenarios, which is a key quality indicator for this type of equipment.

[0029] At the moment the transfer motion ends, the braking impact of the motion axis 20 will excite residual vibration of the scanning head structure. The grating ruler used for positioning in the equipment is mounted on the machine base and can only reflect the platform position. It cannot detect the wobbling at the end of the scanning head. Therefore, the vibration often has not subsided when the positioning signal is issued. If scanning starts immediately at this time, the residual vibration will be reflected on the machining trajectory, leaving vibration marks at the beginning of the partition and aggravating the misalignment of the joint. If a long fixed waiting time is set for safety, the redundant waiting time accumulated from hundreds or thousands of switching will cause considerable production capacity loss. The root of the contradiction is that the residual vibration state is imperceptible, and the waiting time can only be set blindly. It is worth noting that in the configuration where the motion axis 20 carries the workpiece 50, the reaction force of the braking impact will also be transmitted to the scanning head through the bed and support structure, which will also excite the vibration of the scanning head. The relative residual vibration between the workpiece side and the scanning head side will be included in the calibration section later. The solution of this application is applicable to both configurations.

[0030] The core concept of this application is to transform the galvanometer 10 itself into a vibration sensor. During the transfer motion, the galvanometer 10 does not perform scanning, but its servo system remains online. The rotor, along with the reflecting mirror, is suspended at the commanded angle by the servo. The residual vibration of the base is coupled to the mirror through the mounting structure. The angular deviation generated by the servo to maintain the angle thus carries the vibration information of the scanning head end, and it is taken from the position closest to the beam exit. Existing equipment discards this signal entirely during the switching waiting period. This application utilizes this signal as a residual vibration observation channel, thus enabling the equipment to obtain real-time sensing capability of the stabilization process without adding any hardware.

[0031] Figure 2 This is a schematic flowchart illustrating the laser processing galvanometer and axis control switching method provided in an embodiment of this application. (Refer to...) Figure 2 The method includes steps S101 to S106. Step S101: During the transfer motion of the motion axis 20, a holding angle command is issued to the galvanometer 10, causing the galvanometer 10 to be in a holding state. Step S102: The actual angle output by the position detector 11 during the holding state is acquired, and the deviation between the actual angle and the holding angle indicated by the holding angle command is recorded as a holding deviation sequence. Step S103: The maximum absolute value of the deviation is extracted window by window from the holding deviation sequence according to a preset time window to obtain the residual vibration envelope sequence.

[0032] Continue to refer to Figure 2 Step S104: Select a target attenuation template matching the current transfer motion from the pre-built attenuation template library 43, align the residual vibration envelope sequence with the target attenuation template at the deceleration start time of the motion axis 20, and determine the moment when the envelope in the target attenuation template enters the preset allowable amplitude band as the predicted stabilization time. Step S105: Send a light preparation command to the laser 30 ahead of the predicted stabilization time according to the preset light output preparation time. Step S106: When the residual vibration envelope sequence enters the allowable amplitude band, control the galvanometer 10 to switch from the holding state to the scanning state, and perform scanning processing on the current processing partition 52. Figure 2 The diagram also illustrates the exception handling branches and loops when the envelope times out and fails to enter the allowed amplitude band; details of this are elaborated in the timeout protection embodiment below. The implementation methods and design considerations for each step are explained step by step below.

[0033] In step S101, the switching controller 40 sends a transfer motion command to the motion axis 20 and a holding angle command to the driver of the galvanometer 10. The holding angle is usually the deflection angle corresponding to the starting point of the machining pattern in the current machining partition 52, or it can be the zero angle corresponding to the center of the field of view. The so-called holding state means that the servo loop of the galvanometer 10 continues to work in closed loop, locking the reflecting mirror at the holding angle, rather than disconnecting the enable to allow the rotor to stop freely. The reason for emphasizing holding rather than disconnecting the enable is that after the enable is disconnected, the rotor is in a free state, the angle deviation no longer maintains a definite correspondence with the external vibration, and the observation channel disappears. In the holding state, the servo stiffness is determined, and the response of the mirror angle to the vibration of the machine base is stable and calibrable.

[0034] The galvanometer 10 used in this application is a digital galvanometer. Its driver, in addition to receiving angle commands, can also transmit the actual angle measured by the position detector 11 back to the switching controller 40 at fixed intervals. The position detector 11 can be a photoelectric encoder that comes pre-installed with the galvanometer, or a capacitive angle sensor, without the need for additional installation. The feedback link can use an enhanced galvanometer protocol that supports status readback, or an industrial real-time bus, such as EtherCAT. The sampling rate of the feedback is typically in the range of 10,000 to 100,000 points per second, while the structural residual vibration frequency of the cantilever scanning head is generally in the range of tens to hundreds of hertz. The sampling rate is one to three orders of magnitude higher than the vibration frequency, satisfying the sampling theorem and leaving sufficient margin to completely reconstruct the vibration waveform.

[0035] In step S102, the switching controller 40 calculates the difference between the actual angle and the holding angle point by point, and the differences are arranged in chronological order to form the holding deviation sequence. It should be noted that the holding deviation reflects the vibration component in the rotation direction of the galvanometer 10, and its proportional relationship with the actual vibration at the end of the scanning head needs to be established through a one-time calibration. Calibration is performed during the equipment debugging phase, by having the motion axis 20 perform several transfer movements covering typical strokes and speeds, while simultaneously measuring the vibration at the end of the scanning head using an external accelerometer or laser vibrometer. By comparing the two signals, the correspondence coefficient between the holding deviation amplitude and the end vibration amplitude, as well as the effective frequency band, can be obtained. No external instruments are needed during mass production operation.

[0036] This observation channel also has applicable boundaries. The galvanometer 10 is most sensitive to vibrations around its axis of rotation; it can only indirectly sense pure translational components through coupling with the mounting structure, resulting in lower sensitivity. Therefore, the threshold for the allowable amplitude band is calculated using corresponding coefficients during calibration, and a certain margin is reserved before being tightly set, ensuring that when the envelope enters the allowable amplitude band, the actual vibrations in all directions have attenuated to a safe level. Calibration only needs to be performed once during the equipment commissioning phase and does not need to be repeated during mass production; this is the premise for the sensor-free solution to be viable.

[0037] In step S103, the length of the preset time window can be between 0.5 milliseconds and 2 milliseconds, typically 1 millisecond. The switching controller 40 segments the hold-off sequence according to the time window, and takes the maximum absolute value of the deviation within each window. The maximum values ​​of each window are arranged in chronological order to obtain the residual vibration envelope sequence. The residual vibration envelope sequence depicts the outer contour of the vibration amplitude decaying over time, that is, it erases the details of high-frequency oscillations and only leaves the decay trend itself. The maximum absolute value is taken instead of the mean because the maximum value represents the worst case within the window, while the mean value will underestimate the true amplitude of the vibration. Using the maximum value to judge stability is more conservative and safer. When the time window is too short, the envelope is significantly affected by single-point noise; when it is too long, it will smooth out the decay process, resulting in a later judgment of the time when the allowable amplitude band is entered. The above value range is the result of a compromise between the two aspects. The length of the time window should also match the residual frequency. In principle, it should not be less than half a vibration cycle of the lowest frequency of interest. The aforementioned values ​​are applicable to common situations where the frequency is around 500 Hz. For scanning heads with lower frequencies, the time window can be appropriately widened according to this principle. For example, when the frequency is tens of Hz, the time window can be 5 to 25 milliseconds.

[0038] In step S104, the switching controller 40 first determines the range of stroke length and the range of maximum speed for this transfer motion. These two parameters are known quantities when the axis control command is generated. Based on this, the corresponding attenuation template is retrieved from the attenuation template library 43 as the target attenuation template. The attenuation template describes the typical attenuation rhythm of the residual vibration envelope after this type of transfer motion. Its construction method will be explained in detail later. The reason for using stroke length and maximum speed as classification criteria is that they jointly determine the impact energy and excitation spectrum of the deceleration phase, which are two dominant factors affecting the residual vibration attenuation process. Engineering practice shows that transfer motions with similar stroke and speed have highly similar residual vibration attenuation curves.

[0039] Figure 3 This is a schematic diagram illustrating the alignment and switching timing of the residual vibration envelope sequence with the target attenuation template provided in an embodiment of this application. Figure 3 As shown, the alignment is based on the start of deceleration of motion axis 20 as the zero point. There are two considerations for choosing this time as the reference: First, the residual vibration energy mainly comes from the inertial impact of the deceleration phase, and only by taking the start of the impact as the zero point can similar curves coincide; Second, the start of deceleration is directly determined by the timing of the axis control command, and the axis control unit of motion axis 20 notifies the switching controller 40, and the time accuracy is much higher than that of the position signal that depends on the threshold of the grating ruler.

[0040] Figure 3The thin oscillation curve represents the deviation sequence, the thick line adjacent to the oscillation peak represents the residual oscillation envelope sequence, and the dashed line represents the target attenuation template. From left to right, the vertical dashed lines sequentially mark the deceleration start time, the time of issuing the light emission preparation command, the predicted stabilization time, and the time when the envelope actually enters the allowable amplitude band and switches to scanning mode. The interval between the second and third vertical dashed lines represents the preset light emission preparation time. The allowable amplitude band is a corridor where the deviation amplitude does not exceed a preset threshold. To avoid instantaneous band entry misjudgment caused by vibration zero crossing, the residual oscillation envelope sequence is considered to have entered the allowable amplitude band only if it falls within the corridor for several consecutive time windows, such as three consecutive windows. At this point, the residual oscillation has no impact on processing, and this interpretation applies to all subsequent entries into the allowable amplitude band. The time when the target attenuation template enters the corridor is the predicted stabilization time, which can be calculated before deceleration ends. This is the basis for subsequent advance scheduling of light emission preparation.

[0041] In step S105, the light emission preparation command triggers a set of physical actions, including preheating or power ramping of the laser 30 pump source, setting the mechanical shutter or acousto-optic switch, and pre-pressurizing the auxiliary gas path. The duration of these actions ranges from tens to hundreds of milliseconds. The preset light emission preparation time is set by adding a 20-30% margin to the longest duration of each action. For example, if the longest duration of each action is 80 milliseconds, the preset light emission preparation time can be 100 milliseconds. The switching controller 40 issues the command one preset light emission preparation time earlier than the predicted stabilization time, ensuring that the laser 30's readiness time and the scanning head's stabilization time arrive approximately simultaneously. If these actions are started only after the actual stabilization time is reached, each switch requires an additional preparation time after stabilization. Pre-scheduling allows the vibration decay and light emission preparation timelines to converge in parallel, thus completely hiding this preparation time.

[0042] In step S106, the switching controller 40 continuously compares the latest residual vibration envelope sequence with the allowable amplitude band. When the envelope actually enters the allowable amplitude band, the hold angle command is canceled, and the processing trajectory data of the current processing partition 52 is sent to the galvanometer 10. The galvanometer 10 switches from the hold state to the scanning state to start processing. It can be understood that prediction and actual measurement have a clear division of labor in this application. The predicted stable moment is only used to schedule the light output preparation in advance. The actual switching is always based on the measured envelope. No matter how well the template prediction is, it will not exceed this measured threshold. Therefore, the improvement of the cycle time does not come at the expense of processing quality.

[0043] When the equipment is first put into operation or enters a new operating condition, there are no corresponding templates in the attenuation template library 43. Therefore, this application designs a cold start process. During this stage, the switching controller 40 adopts a conservative strategy, performing the switching according to a fixed waiting time set by experience. Simultaneously, it continues to collect the deviation sequence and extract the residual vibration envelope sequence, and archives the envelope curves by category. Once a preset number of entries for the same category have accumulated, such as twenty, an attenuation template for that category is generated, and the system automatically switches to prediction mode. Predictive capability is gradually built up with the accumulation of operating data, requiring no special teaching process and not affecting normal production during the cold start period.

[0044] A further embodiment provides a method for constructing the attenuation template library 43. During historical transfer motions, the device, using the deceleration start moment of the motion axis 20 as the starting point, successively acquires and maintains the deviation sequence and extracts the residual vibration envelope sequence. Each envelope curve, along with the travel length and maximum speed of that transfer motion, is archived and called a historical envelope attenuation curve. The travel length can be divided into intervals of 50 mm, and the maximum speed can be divided into intervals of 0.2 m / s. The granularity of the intervals is adjusted according to the travel and speed range of the device, ensuring that sufficient historical curves are accumulated for each commonly used category. The average value of each historical envelope attenuation curve under the same category is taken at each moment, and the resulting time-by-time average curve is the attenuation template for that category. Taking the average value suppresses measurement noise in single acquisitions and ensures that the template represents the typical attenuation rhythm of that type of working condition, without being skewed by individual abnormal samples.

[0045] While constructing the attenuation template, the duration of each historical envelope attenuation curve under this category from its starting point to entering the allowable amplitude band is statistically analyzed, and the average value is taken as the arrival time label for this category. The arrival time label provides a priori estimate of how long it takes for this type of transfer motion to come to a stop from the start of deceleration. It can be used to verify the rationality of the template entry time and is also a comparison benchmark for the template self-update mechanism described later. When selecting the target attenuation template, it is only necessary to determine the interval to which the travel length and the interval to which the maximum speed of this transfer motion belong, and then retrieve the attenuation template of the corresponding category. The search time is negligible.

[0046] In one embodiment, the galvanometer 10 includes a first scanning axis and a second scanning axis, each of which drives a reflector to perform planar scanning. A position detector 11 is mounted at the end of each scanning axis. Figure 1One of the second scanning axes is shown. At this time, the hold deviation sequences of the first and second scanning axes are acquired respectively, and the residual vibration envelope sequences of each axis are extracted. The cantilever structures and lens inertia of the two axes are different, resulting in different responses to the residual vibration of the base. Often, one axis is already quiet while the other is still wobbling; starting operation on either axis with vibration will leave vibration marks in its corresponding direction. Therefore, the switching condition is taken as the intersection of the two axes, that is, when both the residual vibration envelope sequences of the first and second scanning axes enter the allowable amplitude band, the galvanometer 10 is controlled to switch from the hold state to the scanning state. Correspondingly, the predicted stabilization time is taken as the later of the predicted stabilization times for each of the two axes, so that the light output preparation scheduling is aligned with the axis with slower convergence.

[0047] In another embodiment, the amplitude band is allowed to have a processing-level amplitude threshold and a measurement-level amplitude threshold, with the measurement-level amplitude threshold being smaller than the processing-level amplitude threshold. A processing-ready signal is generated when the residual envelope sequence enters the amplitude band defined by the processing-level amplitude threshold, and a measurement-ready signal is generated when it enters the narrower amplitude band defined by the measurement-level amplitude threshold. Figure 3 The boundary of the allowable amplitude band is drawn with a horizontal dashed line, and the dotted line inside it represents the narrower corridor corresponding to the measurement-level amplitude threshold. The processing-level amplitude threshold is calculated by back-calculating the trajectory tolerance of the starting segment of the partition according to the current process. For example, when the focal length of field lens 12 is 100 mm and the tolerance is 10 micrometers, the corresponding beam deflection angle is approximately 0.1 milliradians. Considering the doubling relationship caused by reflection, it is converted to a mechanical rotation angle of approximately 0.05 milliradians. The processing-level amplitude threshold is set according to the mechanical angle aperture; the measurement-level amplitude threshold can be taken as one-third to one-half of the processing-level amplitude threshold.

[0048] When two threshold levels are set, for partitions where only processing is performed, the predicted stabilization time is determined by the moment when the target attenuation template enters the amplitude band defined by the processing level amplitude threshold. For partitions requiring detection travel, the predicted stabilization time is determined by the moment when the target attenuation template enters the amplitude band defined by the measurement level amplitude threshold. The light output preparation command is still issued in advance of the predicted stabilization time according to the preset light output preparation time, ensuring that the laser 30 is ready when detection begins. When only processing is performed, the generation of the processing ready signal is used as the trigger condition for the galvanometer 10 to switch from the holding state to the scanning state. The measurement level amplitude threshold serves the splicing deviation measurement described later. The measurement requires higher spot stability than processing. The tiered setting allows processing to avoid waiting for measurement, and measurement can be performed in a quieter window.

[0049] A further embodiment introduces timeout protection. If, after a preset timeout period from the predicted stabilization time, the residual envelope sequence still has not entered the allowable amplitude band, then this handover is determined to be an abnormal handover event. This corresponds to... Figure 2The branch where the judgment result is negative and the preset timeout period has elapsed is selected. The preset timeout period can be 30% to 50% of the target attenuation template arrival time tag, or it can be fixed at 50 milliseconds to 200 milliseconds. After the abnormal handover event is determined, the switching controller 40 controls the motion axis 20 to re-execute the positioning motion according to the positioning target of the current processing partition 52, and then re-executes the acquisition of the deviation sequence, the extraction of the residual vibration envelope sequence, and the determination of the predicted stable time. If the envelope fails to converge for a long time, it often means that the transfer has encountered abnormal disturbances, such as foreign objects on the guide rail or changes in the load. Rather than waiting in an abnormal state, it is better to use a low-cost repositioning to obtain a definite initial state. The abnormal handover event is also recorded and archived for maintenance personnel to track trends and troubleshoot potential problems.

[0050] This application also provides an embodiment of online measurement of splicing deviation using a switching window. Figure 4 This is a schematic diagram illustrating the measurement of probe travel and splicing deviation provided in an embodiment of this application. (Refer to...) Figure 4 In response to the measurement ready signal, before the galvanometer 10 switches to scanning mode, the switching controller 40 first controls the laser 30 to emit light at probe power. The probe power is less than the processing power used for scanning, and can be between 5% and 20% of the processing power, with the aim of not leaving visible marks on the surface of the workpiece 50. Subsequently, the galvanometer 10 drives the laser spot to move along the probe stroke, which is planned to intersect with the processed trajectory in the adjacent processed zone 51. The probe stroke is a probe action formed by superimposing a low-speed, micro-amplitude angle command offset in the holding state, and is not considered as switching into scanning mode. After the stroke ends, the galvanometer 10 returns to the vicinity of the holding angle, waiting for the formal switch after correction. The surface morphology and reflectivity at the processed trajectory are significantly different from the surrounding base material, and the reflected light intensity will show a sharp change when the spot sweeps across it. This is the physical signal used for measurement.

[0051] The reflected light intensity is collected by a coaxial photodetector. The coaxial photodetector is a mature component in laser processing heads. It shares the galvanometer 10 and field lens 12 with the processing optical path. The reflected light from the workpiece 50 surface is guided to a photodiode via a beam splitter. This is commonly used in the industry for monitoring the state of the molten pool, and this application directly reuses this existing detection channel. The reflected light intensity signals collected during the detection stroke are arranged chronologically to form a detection signal sequence. The detection stroke is executed at a constant speed, and the position coordinates in the sequence correspond one-to-one with the time. The criteria expressed in terms of time can also be applied based on the position width. Figure 5 This is a schematic diagram of the detection signal sequence provided in the embodiments of this application, as shown below. Figure 5 As shown, the amplitude is stable in the segments that do not intersect with the processed trajectory, while obvious amplitude abrupt changes occur at the intersections.

[0052] The processing of the detection signal sequence involves the following three steps. First, the average amplitude of the segments in the detection path that do not intersect with the processed trajectory is taken as the baseline amplitude. When defining this segment, an appropriate margin is added to both sides of the theoretical position of the processed trajectory to obtain the elimination interval. The part of the detection path outside the elimination interval is the non-intersecting segment, thus ensuring that no abrupt changes are mixed into the baseline. Next, continuous segments in the sequence whose amplitude differs from the baseline amplitude by more than a preset abrupt change threshold are identified. The preset abrupt change threshold can be set to 20% to 50% of the baseline amplitude, depending on the difference in reflectivity between the processed trajectory and the base material. Finally, the midpoint of this continuous segment is determined as the characteristic abrupt change point. The baseline amplitude, the discrimination line obtained by superimposing the preset abrupt change threshold on the baseline amplitude, the continuous segment enclosed by two vertical dashed lines and its width marking, along with the characteristic abrupt change point as the midpoint of the segment, are all included in the analysis. Figure 5 The bid is marked. Figure 5 Taking the case of increased amplitude as an example, when the reflectivity of the processed trajectory is lower than that of the base material, the sudden change is manifested as a drop in amplitude. When identifying, the absolute value of the difference can be taken.

[0053] The position of the light spot at the moment corresponding to the feature mutation point is calculated by converting the actual angle transmitted back by the galvanometer 10. The difference between the position of the light spot and the theoretical position of the processed trajectory in the current processing partition 52 coordinate system is the splicing deviation.

[0054] The splicing deviation describes the misalignment of the current processing zone 52 relative to the adjacent processed zone 51. The switching controller 40 uses the splicing deviation to correct the coordinates of the processing graphic of the current processing zone 52, and then controls the galvanometer 10 to switch to scanning mode after the correction is completed. As a result, the seam misalignment is eliminated before the defect occurs, and the detection time is brought forward from the inspection stage after processing to before the start of processing in this zone. The measurement reference is taken from the existing processing results on the workpiece 50, so there is no need to install a camera, and it is less affected by processing fumes.

[0055] In a further embodiment based on this, the detection stroke includes a first detection stroke and a second detection stroke. The first detection stroke intersects the processed trajectory extending along a first direction, and the second detection stroke intersects the processed trajectory extending along a second direction. The first and second directions are perpendicular to each other. A single detection stroke can only measure the misalignment across the trajectory direction, that is, the translation component perpendicular to the trajectory extension direction. Misalignment along the trajectory direction is not reflected in the signal. Therefore, the splicing deviation determined by the first detection stroke is used as the translation correction amount of the processed graphic coordinates in the direction perpendicular to the first direction, and the splicing deviation determined by the second detection stroke is used as the translation correction amount in the direction perpendicular to the second direction. The two orthogonal strokes combined can measure all translational misalignments in the plane.

[0056] Combination Figure 4The first detection path is drawn horizontally, intersecting with the longitudinally extending processed trajectory. The second detection path is drawn vertically, intersecting with the two horizontally extending processed trajectories. Each intersection point is marked with a solid dot as a characteristic abrupt change point. The dashed line next to the longitudinal processed trajectory represents its theoretical position. The bidirectional arrow between the two paths represents the splicing deviation measured by the first detection path. When the detection path intersects with multiple processed trajectories, continuous segments are identified segment by segment, and characteristic abrupt change points are determined for each segment. The average deviation of each point is taken as the splicing deviation for that path.

[0057] This embodiment also includes an validity criterion. If the time width of a continuous segment corresponding to any detection stroke exceeds a preset width threshold, the detection stroke is deemed invalid. In this case, the galvanometer 10 first returns to the holding angle and re-enters the holding state, and then re-executes the acquisition of the holding deviation sequence and the detection stroke. The normal abrupt change width can be estimated by dividing the sum of the spot diameter and the width of the processed trajectory by the detection speed. The preset width threshold is two to three times the normal width. An abnormally widened abrupt change segment indicates that the spot is still wobbling when it passes over the old trajectory, meaning that the scanning head has not truly stopped. This criterion uses the measurement signal to verify the stopping determination, and it corroborates the residual vibration envelope criterion, forming a double insurance.

[0058] In other embodiments, the device continuously accumulates and utilizes handover data during batch processing. Figure 7 This is a schematic diagram illustrating the process of online updating of the handover archive and deformation field model provided in an embodiment of this application. (Refer to...) Figure 7 After each detection stroke, the current processing partition 52's partition position, the switching time when the galvanometer 10 switches to scanning mode, and the measured splicing deviation are recorded as a handover record and stored in the handover archive 46. The switching time is added to the record after the actual switching action occurs. The slowly changing deformation of the workpiece 50 under clamping stress and processing heat input is not random; its distribution constitutes a regular field that changes continuously with position and time. Therefore, using the partition position and switching time of each handover record in the handover archive 46 as input and the splicing deviation as output, an online machine learning regression model is trained to obtain the deformation field model 47. The regression model can be a linear model with a regularization term, such as ridge regression, or a Gaussian process regression to simultaneously provide the prediction confidence level. Both types of models have very low computational cost under the sample size of this application, and can be run in real time by an embedded controller. This application embodiment does not impose any limitations on this.

[0059] The purpose of deformation field model 47 is pre-correction. For unprocessed processing zones, the zone's location and the expected switching time determined according to the processing schedule are input into deformation field model 47 to obtain the predicted splicing deviation. Before the detection stroke of this zone, pre-correction is performed on its processing graphic coordinates according to the predicted splicing deviation. Subsequently, the splicing deviation of this zone, obtained from the actual measurement of the detection stroke, is further corrected based on the pre-correction. Pre-correction handles the main part of the deviation, and the detection stage only needs to process the remaining small amount. The requirement for the accuracy of abrupt change identification is reduced accordingly. Even if a detection stroke is deemed invalid, pre-correction still provides a backup, and the processing quality of the zone is still guaranteed.

[0060] A further embodiment provides an online training method for the deformation field model 47. A training sample set is constructed using a first preset number of recently stored handover records in the handover archive 46. This first preset number can be between 50 and 200 records. For each newly added handover record, an incremental update is performed on the regression model using the training sample set. The incremental update of ridge regression can be implemented using recursive least squares with a forgetting factor. The influence of older samples naturally decays as the window slides out. The computational cost of a single update is only proportional to the square of the feature dimension, and can be completed in microseconds, without affecting the processing cycle. A sliding window sample set is used instead of the full sample set to ensure the model always tracks the most recent deformation state. Records from too long ago correspond to altered thermal states, and retaining them would introduce errors.

[0061] The template side also has self-updating capabilities. The attenuation template library 43 stores attenuation templates categorized by travel length and maximum speed intervals. After each switch, the time from the start of deceleration to actually entering the allowable amplitude band in the residual vibration envelope sequence is recorded as the measured arrival time. The difference between the measured arrival time and the arrival time label of the target attenuation template is recorded as a template deviation sample. When the absolute value of the mean of the most recent second-preset number of template deviation samples in the same category exceeds the preset update threshold, the time-by-time mean curve is recalculated using the most recently collected historical envelope attenuation curves in that category, updating the attenuation template for that category. Based on absolute value comparison, drift in both directions of attenuation acceleration and deceleration can trigger an update. The second preset number can be 10 to 30, and the preset update threshold can be approximately 15% of the arrival time label. Changes in guide rail wear, lubrication status, and load conditions will slowly alter the attenuation rhythm. Threshold-triggered updates can keep up with this drift without being triggered by unnecessary jitter by individual abnormal samples, thus maintaining accurate stopping prediction throughout the entire equipment lifecycle.

[0062] Based on the same inventive concept, embodiments of this application also provide a laser processing galvanometer and axis control switching system, the composition of which is as follows: Figure 1As shown, the system includes a galvanometer 10, a motion axis 20, a laser 30, and a switching controller 40. The galvanometer 10 is equipped with a position detector 11. The motion axis 20 is used to perform transfer motions between adjacent processing zones; the galvanometer 10 is used to perform scanning processing on each processing zone and is held in a holding state according to a holding angle command during the transfer motion of the motion axis 20; the laser 30 is scheduled to emit light by the switching controller 40.

[0063] Figure 6 This is a schematic diagram of the switching controller provided in an embodiment of this application. (Refer to...) Figure 6 The switching controller 40 is provided with a holding deviation acquisition module 41, an envelope extraction module 42, and a stability prediction module 44 sequentially along the signal flow direction. The stability prediction module 44 is connected to an attenuation template library 43, and a switching trigger module 45 is provided at the end. In one embodiment, the switching controller 40 further includes a handover archive library 46 and a deformation field model 47.

[0064] The hold-off acquisition module 41 performs the processing of the aforementioned step S102, receiving the actual angle output by the position detector 11 and generating a hold-off sequence; the envelope extraction module 42 performs the window-by-window extraction of step S103, with one output sent to the stable prediction module 44, and the other output sent to... Figure 6 The bypass signal is sent to the switching trigger module 45 for actual measurement comparison; the attenuation template library 43 stores attenuation templates by category, which are used by the stability prediction module 44 to complete the template selection in step S104; the stability prediction module 44 receives the deceleration start time notified by the axis control unit of the motion axis 20, completes the template alignment and determines the predicted stabilization time, and sends a light preparation command to the laser 30 according to the timing sequence of step S105; the switching trigger module 45 performs the comparison in step S106 and sends a command to the galvanometer 10 to switch to the scanning state. The processing details of each module correspond one-to-one with the method embodiment described above, and will not be repeated here.

[0065] The above modules can be implemented in software and run on the CNC system of the laser processing equipment or a separate embedded control board. For envelope comparison and switching triggering links with strict response time requirements, they can also be implemented with FPGA logic to ensure microsecond-level deterministic delay. The specific implementation form is not limited in the embodiments of this application.

[0066] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features, and such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A method for switching between a laser processing galvanometer and axis control, applied to the laser processing process of an intelligent welding system or metal cutting and welding equipment, wherein the laser processing process involves a galvanometer scanning each processing zone, and a motion axis performing transfer motion between adjacent processing zones, characterized in that... include: During the transfer motion of the motion axis, a holding angle command is sent to the galvanometer to keep the galvanometer in a holding state; The actual angle output by the position detector of the galvanometer is collected during the holding state, and the deviation between the actual angle and the holding angle indicated by the holding angle command is recorded as a holding deviation sequence; The maximum absolute value of the deviation is extracted window by window from the holding deviation sequence according to the preset time window to obtain the residual vibration envelope sequence; Select a target attenuation template that matches the transfer motion from a pre-built attenuation template library, align the residual vibration envelope sequence with the target attenuation template at the deceleration start time of the motion axis, and determine the time when the envelope in the target attenuation template enters the preset allowable amplitude band as the predicted stable time. A light preparation command is sent to the laser ahead of the predicted stabilization time according to the preset light emission preparation time; when the residual vibration envelope sequence enters the allowed amplitude band, the galvanometer is controlled to switch from the holding state to the scanning state to perform scanning processing on the current processing partition, which is the processing partition reached by the transfer motion.

2. The laser processing galvanometer and axis control switching method according to claim 1, characterized in that, The attenuation template library is constructed as follows: during the historical transfer motion, taking the deceleration start time of the motion axis as the time starting point, the holding deviation sequence corresponding to each historical transfer motion is collected and the corresponding residual vibration envelope sequence is extracted as the historical envelope attenuation curve. The historical envelope attenuation curves are classified according to the interval of the travel length of the transfer motion and the interval of the maximum speed. The time-by-time average curve of each historical envelope attenuation curve in the same category is used as the attenuation template of that category. The average of the time from the starting point of the time to the entry into the allowable amplitude band of each historical envelope attenuation curve in that category is used as the arrival time label of that category. The method for selecting the target attenuation template is as follows: determine the interval to which the travel length of the transfer motion belongs and the interval to which the maximum speed belongs, and determine the attenuation template of the corresponding category as the target attenuation template.

3. The laser processing galvanometer and axis control switching method according to claim 1, characterized in that, The galvanometer includes a first scanning axis and a second scanning axis, respectively acquiring the hold bias sequence of the first scanning axis and the hold bias sequence of the second scanning axis, and respectively extracting the residual envelope sequence of the first scanning axis and the residual envelope sequence of the second scanning axis; When the residual vibration envelope sequence of the first scanning axis and the residual vibration envelope sequence of the second scanning axis both enter the allowed amplitude band, the galvanometer is controlled to switch from the holding state to the scanning state. The predicted stabilization time is the later of the predicted stabilization time corresponding to the first scan axis and the predicted stabilization time corresponding to the second scan axis.

4. The laser processing galvanometer and axis control switching method according to claim 1, characterized in that, The allowable amplitude band has a processing-level amplitude threshold and a measurement-level amplitude threshold, wherein the measurement-level amplitude threshold is smaller than the processing-level amplitude threshold; A processing ready signal is generated when the residual vibration envelope sequence enters the amplitude band defined by the processing stage amplitude threshold, and a measurement ready signal is generated when the residual vibration envelope sequence enters the amplitude band defined by the measurement stage amplitude threshold. The generation of the processing ready signal is used as the trigger condition for controlling the galvanometer to switch from the holding state to the scanning state.

5. The laser processing galvanometer and axis control switching method according to claim 1, characterized in that, If the residual vibration envelope sequence still fails to enter the allowable amplitude band after a preset timeout period from the predicted stabilization time, the current switch is determined to be an abnormal handover event. The motion axis is then controlled to re-execute the positioning motion according to the positioning target of the current processing zone, and the acquisition of the holding deviation sequence, the extraction of the residual vibration envelope sequence, and the determination of the predicted stabilization time are re-executed.

6. The laser processing galvanometer and axis control switching method according to claim 4, characterized in that, Also includes: In response to the measurement ready signal, before controlling the galvanometer to switch from the holding state to the scanning state, the laser is controlled to emit light at a probe power less than the processing power used in the scanning process; The galvanometer is controlled to drive the laser spot to move along the detection path, and the detection path intersects with the processed trajectory in the adjacent processed zone; The reflected light intensity signal from the workpiece surface during the detection stroke is collected by a coaxial photodetector to form a detection signal sequence; The mean amplitude of the detection signal sequence corresponding to the segment in the detection path that does not intersect with the processed trajectory is determined as the baseline amplitude. A continuous segment in the detection signal sequence whose amplitude differs from the baseline amplitude by a preset abrupt change threshold is identified, and the midpoint of the continuous segment is determined as the characteristic abrupt change point. The difference between the spot position obtained by converting the actual angle of the galvanometer at the time corresponding to the feature mutation point and the theoretical position of the processed trajectory in the coordinate system of the current processing partition is determined as the splicing deviation. The splicing deviation is used to correct the coordinates of the processing graphic in the current processing zone. After the correction is completed, the galvanometer is controlled to switch from the holding state to the scanning state.

7. The laser processing galvanometer and axis control switching method according to claim 6, characterized in that, The detection travel includes a first detection travel and a second detection travel. The first detection travel intersects with the processed trajectory extending along a first direction, and the second detection travel intersects with the processed trajectory extending along a second direction. The first direction and the second direction are perpendicular to each other. The splicing deviation determined by the first detection stroke is used as the translation correction amount of the processing graphic coordinates of the current processing partition in the direction perpendicular to the first direction, and the splicing deviation determined by the second detection stroke is used as the translation correction amount of the processing graphic coordinates of the current processing partition in the direction perpendicular to the second direction. When the time width of the continuous segment corresponding to any detection stroke exceeds the preset width threshold, the detection stroke is determined to be invalid, and the acquisition of the bias sequence and the detection stroke are re-executed.

8. The laser processing galvanometer and axis control switching method according to claim 6, characterized in that, Also includes: After each detection journey is completed, the partition position of the current processing partition, the switching time of the galvanometer to the scanning state, and the splicing deviation are stored as a handover record in the handover archive. Using the partition position and switching time of each handover record in the handover archive as input and the splicing deviation of each handover record as output, an online machine learning regression model is trained to obtain a deformation field model. For unprocessed processing zones, the zone location and the expected switching time determined according to the processing schedule are input into the deformation field model to obtain the predicted splicing deviation. Before the detection stroke of the processing zone is executed, the processing graphic coordinates of the processing zone are pre-corrected according to the predicted splicing deviation. The splicing deviation obtained from the detection stroke of the processing zone is used to further correct the processing graphic coordinates of the processing zone based on the pre-correction.

9. The laser processing galvanometer and axis control switching method according to claim 8, characterized in that, The online training method for the deformation field model is as follows: a training sample set is formed by the first preset number of recently stored handover records in the handover archive, and an incremental update is performed on the machine learning regression model using the training sample set after each new handover record is added. It also includes: the attenuation template library stores attenuation templates according to the interval of the travel length of the transfer motion and the interval of the maximum speed; the target attenuation template is provided with an arrival time label; the arrival time label is the average of the time from the deceleration start time to the entry into the allowable amplitude band for each historical envelope attenuation curve that constructs the attenuation template. The duration from the start of deceleration to entering the allowable amplitude band of the residual vibration envelope sequence is recorded as the measured arrival time, and the difference between the measured arrival time and the arrival time label is recorded as the template deviation sample. When the mean of the second preset number of template deviation samples in the same category exceeds the preset update threshold, the time-by-time mean curve is recalculated using the most recently collected historical envelope decay curves in that category, and the decay template of that category is updated.

10. A laser processing galvanometer and axis control switching system for implementing the method of claim 1, characterized in that, Includes galvanometer, motion axis, laser, and switching controller; The motion axis is used to perform transfer motion between adjacent processing zones; The galvanometer is equipped with a position detector. The galvanometer is used to perform scanning processing on each processing zone and to remain in a holding state according to the holding angle command during the transfer motion of the motion axis. The switching controller includes a bias acquisition module, an envelope extraction module, an attenuation template library, a stability prediction module, and a switching trigger module; The holding deviation acquisition module is used to acquire the actual angle output by the position detector during the holding state, and record the deviation between the actual angle and the holding angle indicated by the holding angle command as a holding deviation sequence; The envelope extraction module is used to extract the maximum value of the absolute value of the deviation from the holding deviation sequence window by window according to a preset time window, so as to obtain the residual vibration envelope sequence. The attenuation template library is used to classify and store attenuation templates according to the range of travel length and the range of maximum speed of the transfer motion; The stability prediction module is used to select a target attenuation template that matches the transfer motion from the attenuation template library, align the residual vibration envelope sequence with the target attenuation template according to the deceleration start time of the motion axis, determine the time when the envelope in the target attenuation template enters the preset allowable amplitude band as the predicted stability time, and send a light preparation command to the laser ahead of the predicted stability time according to the preset light preparation time. The switching trigger module is used to control the galvanometer to switch from the holding state to the scanning state when the residual vibration envelope sequence enters the allowed amplitude band, and to perform scanning processing on the current processing partition, wherein the current processing partition is the processing partition reached by the transfer motion.

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