Laser cutting device with self-adaptive fixing structure and method thereof

Abstract

The invention discloses a laser cutting device with a self-adaptive fixing structure and a method of the laser cutting device, and belongs to the technical field of cutting. The self-adaptive clamp table is mounted on the machine tool base; wherein the self-adaptive clamp table comprises a grid supporting plate and a supporting and clamping unit array; the grid supporting plate is fixed to the machine tool base, and array through holes are distributed in the grid supporting plate. The supporting and clamping unit array is arranged below the grid supporting plate and comprises a plurality of supporting and clamping units which can independently extend out and penetrate through the array through holes; the three-dimensional vision system is erected above the machine tool base; and the controller is electrically connected with the supporting and clamping unit array and the three-dimensional visual system, the system can immediately execute the supplementary supporting action, further development of deformation is effectively restrained, and it is ensured that workpieces can be kept stable in the whole machining period.

Description

Technical Field

[0001] This invention relates to the field of cutting, specifically to a laser cutting device and method with an adaptive fixing structure. Background Technology

[0002] In laser cutting applications, traditional planar or general-purpose fixtures struggle to provide effective support for thin sheet workpieces with surface warping or irregular shapes. This not only affects cutting accuracy but can also lead to deformation of the workpiece due to thermal stress release during processing, causing collisions between the laser head and the workpiece or fixture.

[0003] To ensure cutting safety, it is usually necessary to monitor the workpiece's condition during processing. Sensors are used to acquire real-time workpiece status data, and the purpose of conventional monitoring is to ensure workpiece stability. Under the influence of external environment and cutting thermal stress, workpieces are prone to deformation, warping, and vibration. Existing technology can acquire workpiece deformation data and classify safety based on the monitoring data. However, in reality, the monitoring data contains significant noise and some data that has little impact on the workpiece's condition. Directly classifying safety based on monitoring data can easily lead to inaccurate safety classifications, thus posing significant safety hazards.

[0004] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] The purpose of this invention is to provide a laser cutting device and method with an adaptive fixed structure to solve the problems mentioned in the background art.

[0006] The technical solution of the present invention includes: Machine tool base; An adaptive fixture table is mounted on the machine tool base; The adaptive fixture stage includes a grid support plate and a support and clamping unit array; The grid support plate is fixed to the machine tool base, and an array of through holes is arranged on it; The support clamping unit array is disposed below the grid support plate, and includes multiple support clamping units that can extend independently and pass through the array through holes; A three-dimensional vision system is mounted above the machine tool base; The controller is electrically connected to the support clamping unit array and the three-dimensional vision system; The controller is used to control the movement of the support clamping unit array to form an interference-free fixation of the workpiece based on the three-dimensional digital model generated by the three-dimensional vision system scanning the workpiece and the preset laser cutting path.

[0007] Preferably, each of the support clamping units includes: A miniature cylinder, the cylinder body of which is fixed to a mounting base plate; The piston rod is vertically disposed inside the miniature cylinder; A support head, connected to the top of the piston rod, is used for flexible contact with the workpiece.

[0008] Preferably, an electromagnet is integrated within the support head of some of the support clamping units to form a clamping unit for generating an adsorption force on a magnetically conductive workpiece.

[0009] Preferably, the three-dimensional vision system includes: A gantry frame is movably mounted on the machine tool base; The scanning module is mounted on the gantry frame and can move along it; The scanning module includes a structured light projector and an industrial camera.

[0010] A laser cutting method with an adaptive fixing structure includes: The 3D vision system is driven to scan the workpiece to obtain 3D point cloud data; A three-dimensional digital model is constructed based on the three-dimensional point cloud data, wherein the three-dimensional digital model is used to characterize the three-dimensional contour and surface warpage of the workpiece; Retrieve preset laser cutting path data; Based on the three-dimensional digital model and the laser cutting path data, an interference-free fixing scheme is generated, wherein the interference-free fixing scheme is used to define the combination of the support and clamping units to be activated and their respective target motion parameters; The support clamping unit array is controlled to execute the interference-free fixing scheme to complete the initial fixing of the workpiece; Record the support pressure of each activated support clamping unit after the initial fixing is completed, and use it as the initial support pressure reference. During the laser cutting process, the support pressure of each activated support clamping unit is monitored in real time to generate real-time support pressure data; Based on the comparison between the real-time support pressure data and the initial support pressure benchmark, it is determined whether the workpiece has undergone unstable deformation. When it is determined that the workpiece has undergone unstable deformation, the currently inactive support and clamping unit is controlled to perform a supplementary support action; If it is determined that the workpiece has not undergone unstable deformation, the current laser cutting process is maintained.

[0011] Preferably, the step of generating the interference-free fixation scheme includes: The laser cutting path data is superimposed onto the three-dimensional digital model; Based on the surface warpage of the workpiece, the support clamping unit located in the low-lying area below the workpiece is preferentially selected as the support point. For each selected support clamping unit, the workpiece bottom surface height coordinate value at the corresponding position of the unit is extracted from the three-dimensional digital model, and the difference between the height coordinate value and the reference plane height of the grid support plate is used as the target extension height of the support clamping unit. In the area at the edge of the workpiece model and away from the cutting path, a clamping unit with an electromagnet is selected as the clamping point. Simulate the movement trajectory of the laser head and check whether it interferes with any selected support or clamping unit; If interference occurs, the conflicting unit is replaced and the process is repeated until a final interference-free fixation solution is obtained.

[0012] Preferably, the source of the initial support pressure reference is: After the initial fixing is completed and before the laser cutting begins, the internal cylinder air pressure of each activated support clamping unit is accurately read, and the reading value of the air pressure is recorded as the initial support pressure reference for that support point.

[0013] Preferably, the step of determining whether the workpiece has undergone unstable deformation includes: Calculate the difference between the real-time support pressure data and the initial support pressure benchmark to obtain the pressure deviation. The absolute value of the pressure deviation and the rate of change of the pressure deviation per unit time are weighted and summed to generate a deformation trend characteristic value. The deformation trend characteristic value is compared with a preset dynamic instability safety threshold, wherein the dynamic instability safety threshold is a safety limit value preset according to the processing material, plate thickness and cutting process parameters; When the deformation trend characteristic value exceeds the dynamic instability safety threshold, it is determined that the workpiece has undergone unstable deformation. When the deformation trend characteristic value does not exceed the dynamic instability safety threshold, it is determined that the workpiece has not undergone unstable deformation.

[0014] This invention provides a laser cutting device and method with an adaptive fixing structure, which has the following improvements and advantages compared with the prior art: By acquiring the precise 3D contour of the workpiece through a 3D vision system, the controller can generate a customized support contour that perfectly matches the bottom shape of the workpiece. This precise adaptive fixation can effectively correct the warping of the workpiece and provide stable support, laying the foundation for precise cutting. Before fixing the workpiece, the controller simulates the movement trajectory of the laser head and checks whether it interferes with any support or clamping unit. If interference occurs, the system will automatically replace the conflicting unit and recheck to ensure that the final fixation scheme can guarantee that the laser cutting path is completely free of interference. This significantly improves the safety of the processing. A step of real-time monitoring of support pressure during the cutting process is introduced. By comparing the real-time pressure data with the initial reference, the system can determine whether the workpiece has become unstable and deformed. Once deformation is detected, the system will immediately perform supplementary support action to effectively suppress the further development of deformation and ensure that the workpiece remains stable throughout the entire processing cycle. Attached Figure Description

[0015] The present invention will be further explained below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of the overall structure of the device; Figure 2 This is a schematic diagram of the structure of a 3D vision system; Figure 3 This is a schematic diagram of the adaptive fixture stage; Figure 4 This is a schematic diagram of the process flow of the method of the present invention.

[0016] In the diagram: 100, machine tool base; 200, adaptive fixture table; 210, grid support plate; 220, support and clamping unit array; 221, miniature cylinder; 222, piston rod; 223, support head; 300, 3D vision system; 310, gantry frame; 320, scanning module. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0018] Example 1: Please see Figure 1-3 The present invention provides a laser cutting device with an adaptive fixing structure, comprising: Machine tool base 100; An adaptive fixture table 200 is mounted on a machine tool base 100; The adaptive fixture stage 200 includes a grid support plate 210 and a support and clamping unit array 220. The grid support plate 210 is fixed on the machine tool base 100, and an array of through holes is arranged on it; The support clamping unit array 220 is disposed below the grid support plate 210, and includes multiple support clamping units that can extend independently and pass through the array through holes; The support clamping unit array 220 consists of multiple independent support clamping units arranged in a plane at a preset fixed interval to form a regular matrix layout, so as to ensure uniform coverage and support for the entire working area under the grid support plate 210. A 3D vision system 300 is mounted above the machine tool base 100; The controller is electrically connected to the support clamping unit array 220 and the three-dimensional vision system 300; The controller is used to control the movement of the support clamping unit array 220 to form an interference-free fixation of the workpiece based on the three-dimensional digital model generated by the three-dimensional vision system 300 scanning the workpiece and the preset laser cutting path.

[0019] In laser cutting applications, traditional planar or general-purpose fixtures are difficult to provide effective fit and support for thin sheet workpieces with surface warping or irregular shapes. This not only affects cutting accuracy but may also cause deformation of the workpiece due to the release of thermal stress during processing, leading to collisions between the laser head and the workpiece or fixture. This embodiment provides a laser cutting device with an adaptive fixing structure, which aims to solve the problems of traditional fixtures being unable to provide effective fit and support and being prone to deformation due to the release of thermal stress. Because the controller in this device is connected to the 3D vision system 300 and the adaptive fixture stage 200, the 3D vision system 300 can acquire the complete surface contour information of the workpiece non-contactly and generate a 3D digital model. Therefore, the controller can receive this model and, in conjunction with the preset laser cutting path, analyze the low-lying areas of the workpiece through the built-in algorithm and plan an interference-free cutting trajectory. Based on this analysis result, the controller sends independent action commands to the support clamping unit array 220, causing some units to extend from the through holes of the grid support plate 210, forming a customized support contour that perfectly matches the bottom shape of the workpiece, thereby achieving stable and interference-free fixation of the workpiece, providing a foundation for subsequent precise cutting.

[0020] The controller can be a Siemens S7-1500 series PLC, which has the ability to handle complex calculations and multi-axis control; specifically, the S7-1517F-3PN / DP model can be selected, which has sufficient processing power and communication interface to implement the complex algorithm of this invention; the algorithm for generating the interference-free fixing scheme can be implemented in the structured text programming language of the PLC, and the motion trajectory of the laser head can be simulated by calling motion control library functions.

[0021] Each support clamping unit includes: Miniature cylinder 221, the cylinder body of which is fixed to the mounting base plate; The piston rod 222 is vertically disposed inside the miniature cylinder 221; The support head 223 is connected to the top of the piston rod 222 and is used for flexible contact with the workpiece.

[0022] The universal ball joint structure can consist of a ball socket fixed at the top of the piston rod 222 and a ball at the bottom of the support head 223. The two are connected by a snap-fit ​​or magnetic attraction, allowing the support head 223 to deflect freely within a certain angle range to accommodate local tilting of the workpiece. The support head 223 can be made of a wear-resistant and flexible non-metallic material, such as polyurethane, silicone rubber, or soft polytetrafluoroethylene. The support and clamping unit in this embodiment has an internal structure that is a precise linear motion mechanism. The miniature cylinder 221 is the power source of this unit. Its cylinder body is stably fixed to the mounting base plate, ensuring the reference stability of the movement. Here, the miniature cylinder 221 can be a commercially available standard part, such as the SMC CJP2 series needle cylinder, which has the characteristics of fast response speed and small size. The piston rod 222, as the motion actuator, receives the drive of compressed air inside the miniature cylinder 221 and performs reciprocating linear motion in the vertical direction. The support head 223 is installed at the end of the piston rod 222 and is the part that directly contacts the workpiece. In order to avoid scratches or indentations on the workpiece surface during the contact process, the support head 223 can be made of non-metallic materials with a certain degree of flexibility, such as polyurethane, silicone rubber, or soft polytetrafluoroethylene. The connection between the support head 223 and the piston rod 222 is not a rigid connection, but a universal ball joint structure. This connection method allows the support head 223 to rotate freely within a small range, so as to better fit the local tilt of the workpiece surface, achieve flexible contact, and improve the adaptability of the support.

[0023] The support head 223 of the partial support clamping unit integrates an electromagnet to form a clamping unit, which is used to generate an adsorption force on the magnetically conductive workpiece.

[0024] The clamping unit in this embodiment adds a force application method to the aforementioned support clamping unit. Specifically, a miniature electromagnet is embedded inside a portion of the support head 223. When the workpiece being processed is a magnetically conductive material such as a steel plate, the controller, while driving the miniature cylinder 221 of this unit to extend and provide vertical support force, simultaneously energizes the electromagnet inside. After energization, the electromagnet generates a magnetic field, producing a vertically downward magnetic attraction force on the magnetically conductive workpiece located above it. This design allows the clamping unit to not only support the workpiece but also secure it to the support head through magnetic attraction. This magnetic attraction force is vertically downward, opposite to the direction of the support force, together forming a stable constraint on the workpiece. This magnetic constraint mechanism is effective in suppressing minor vibrations of the workpiece during the cutting process and preventing warping that may occur due to the cutting path being close to the edge, further enhancing the reliability of workpiece fixation.

[0025] The 3D vision system 300 includes: The gantry frame 310 is movably mounted on the machine tool base 100; The scanning module 320 is mounted on the gantry frame 310 and can move along it; The scanning module 320 includes a structured light projector and an industrial camera.

[0026] The 3D vision system 300 in this embodiment is designed to efficiently and accurately acquire global 3D data of the workpiece. The system achieves coverage of the entire working area through a gantry frame 310. The gantry frame 310 consists of a crossbeam spanning guide rails on both sides of the machine tool base 100, which can be driven by a servo motor to achieve a wide range of movement. The scanning module 320, mounted on the crossbeam, is also driven by an independent servo motor and can reciprocate on the crossbeam. This dual-axis motion structure allows the scanning module 320 to reach any position above the workpiece. The core of the scanning module 320 is a combination of a structured light projector and an industrial camera; here, the industrial camera can be a Basler ACE series camera. During operation, the structured light projector projects a pre-coded grating pattern onto the workpiece surface. Due to the unevenness of the workpiece surface, the grating pattern captured by the industrial camera from another angle will undergo corresponding deformation. After receiving these images with deformation information, the controller, based on the principle of triangulation, can calculate the spatial 3D coordinates corresponding to each point in the image, thereby constructing high-density point cloud data of the workpiece surface.

[0027] Example 2 Please see Figure 4 A laser cutting method with an adaptive fixing structure, comprising: Drive a 3D vision system to scan a workpiece 300 times to obtain 3D point cloud data; A three-dimensional digital model is constructed based on three-dimensional point cloud data. The three-dimensional digital model is used to characterize the three-dimensional contour and surface warpage of the workpiece. Retrieve preset laser cutting path data; Based on the three-dimensional digital model and laser cutting path data, an interference-free fixing scheme is generated. The interference-free fixing scheme is used to define the combination of support and clamping units to be activated and their respective target motion parameters. The control support clamping unit array 220 executes an interference-free fixing scheme to complete the initial fixing of the workpiece; Record the support pressure of each activated support clamping unit after the initial fixing is completed, and use it as the initial support pressure reference. During the laser cutting process, the support pressure of each activated support clamping unit is monitored in real time to generate real-time support pressure data; Based on the comparison between real-time support pressure data and the initial support pressure benchmark, it is determined whether the workpiece has undergone unstable deformation. When it is determined that the workpiece has undergone unstable deformation, the currently inactive support and clamping unit is controlled to perform a supplementary support action; If it is determined that the workpiece has not undergone unstable deformation, the current laser cutting process is maintained.

[0028] The execution logic of the supplementary support action is as follows: The controller first calculates the deformation center position of the workpiece based on the pressure deviation distribution of each activated support point using a weighted interpolation algorithm. Specifically, the controller uses the coordinates of each support point with abnormal pressure as the reference point and the absolute value of its pressure deviation as the weighting coefficient to calculate the weighted centroid coordinates, which are the calculated deformation center position. Around the deformation center position, the controller searches for the nearest unactivated support clamping unit, calculates the target height that these units need to extend, and determines the target height by reading the workpiece bottom surface height at the corresponding position in the three-dimensional digital model and adding a preset support margin to provide additional support force and activate them. If one unit is insufficient to stabilize the workpiece, the system can gradually activate more adjacent units until the deformation trend characteristic value returns to below the safety threshold.

[0029] The laser cutting method with an adaptive fixed structure used in this embodiment is a dynamic perception and response process. The method starts with the accurate perception of the workpiece geometry, that is, by driving the three-dimensional vision system 300 to scan and obtain the original three-dimensional point cloud data. The controller processes these discrete point cloud data, for example, by using point cloud stitching and surface fitting algorithms to construct a three-dimensional digital model that can completely represent the three-dimensional contour and surface warping of the workpiece.

[0030] The computational logic of this process is as follows: the controller performs point cloud stitching, which aims to unify the point cloud data acquired from multiple scans and located in different local coordinate systems into a global coordinate system by identifying the overlapping areas between the data and calculating the coordinate transformation matrix, thus forming a complete workpiece point cloud. The controller then performs surface fitting on this complete point cloud, which aims to use mathematical functions, such as non-uniform rational B-splines, to generate a continuous and smooth mathematical surface that can pass through or approximate these discrete points. This continuous surface is the final three-dimensional digital model, which not only accurately reproduces the geometry of the workpiece but also makes subsequent warpage analysis and interference calculations possible.

[0031] The controller retrieves preset laser cutting path data and fuses these two data sources to generate an interference-free fixation scheme. This scheme clarifies which support and clamping units need to be activated and the precise extension height of each unit. The controller then instructs the support and clamping unit array 220 to execute this scheme, completing the initial fixation of the workpiece. This process then enters a continuous monitoring phase. The controller records the support pressure of each activated unit after the initial fixation and uses this as the initial support pressure reference. During cutting, the controller collects real-time support pressure data of each unit at high frequency. By comparing the difference between the real-time data and the reference data, it determines whether the workpiece has become unstable due to the release of internal stress or thermal effects caused by cutting. Once unstable deformation is detected, the controller immediately instructs previously inactive support and clamping units near the deformation area to provide additional support to suppress further deformation. If the workpiece is determined to be stable, the current cutting operation is maintained. This series of steps ensures that the workpiece remains stable throughout the entire processing cycle.

[0032] The steps to generate an interference-free fixation scheme include: Overlay laser cutting path data onto a 3D digital model; Based on the surface warpage of the workpiece, the support and clamping unit located in the low-lying area below the workpiece is preferred as the support point. For each selected support clamping unit, the workpiece bottom surface height coordinate value at the corresponding position of the unit is extracted from the three-dimensional digital model, and the difference between the height coordinate value and the reference plane height of the grid support plate is used as the target extension height of the support clamping unit. In the area at the edge of the workpiece model and far from the cutting path, select a clamping unit with an electromagnet as the clamping point; Simulate the movement trajectory of the laser head and check whether it interferes with any selected support or clamping unit; If interference occurs, the conflicting unit is replaced and the process is repeated until a final interference-free fixation solution is obtained.

[0033] The logic for replacing conflicting units is as follows: First, select the candidate unit furthest from the cutting path and adjacent to the active unit for replacement; if no suitable adjacent unit is found, select from the entire candidate unit library until a combination that does not interfere is found. This iterative process usually converges within a preset finite number of iterations. If no solution is found after exceeding the limit, the system will indicate that it cannot generate a non-interference fixed solution.

[0034] In this embodiment, the calculation process for generating an interference-free fixing scheme is a multi-objective optimization decision-making process. In the digital space, the controller accurately superimposes the laser cutting path data onto the constructed three-dimensional digital model. The algorithm analyzes the surface warpage of the model and preferentially selects the support clamping unit located in the low-lying area below the workpiece as the support point.

[0035] The controller determines the target extension height of each support unit in the following way: extracting the height field data of the bottom surface of the workpiece from the three-dimensional digital model, with the upper surface of the grid support plate as the Z=0 reference plane; for each unit selected as a support point, reading its coordinate position in the array and querying the workpiece bottom surface height value Z corresponding to that position; using the height value Z as the target extension height of the piston rod of the support unit, so that the support head just contacts the bottom surface of the workpiece.

[0036] The purpose of this selection is that when these units extend, they can lift and correct the originally warped workpiece to a near-horizontal state. At the same time, to ensure the stability of the workpiece edge, the algorithm will select positions with sufficient safety distance from the cutting path in the edge area of ​​the workpiece model and designate clamping units with electromagnets as clamping points. After completing the initial placement, the critical interference check stage begins. The controller will establish a virtual three-dimensional envelope containing safety margins for the laser head and each selected support or clamping unit.

[0037] The basic dimensions of the envelope are determined by the maximum outline of the laser head or support clamping unit in three-dimensional space. The safety margin is the additional buffer distance added to each dimension of this basic size. This distance is not arbitrarily set, but is determined after comprehensively considering factors such as the positioning accuracy error of the equipment itself, the slight thermal expansion that may occur during the workpiece cutting process, and the potential dynamic deviation of the laser head movement. By increasing this safety margin, it can be ensured that even under extreme conditions, the simulated interference-free path is equally safe in actual execution.

[0038] The system will simulate the entire trajectory of the laser head. During the simulation, the system will continuously check whether the envelope of the laser head spatially overlaps with the envelope of any support or clamping unit. If interference is detected, the algorithm will remove the conflicting unit and select one from its neighboring alternative units for replacement, and then restart the complete trajectory simulation check. This iterative process of selection-simulation-check-replacement will continue until a final solution is found that satisfies the support stability requirements and does not interfere with the laser head's trajectory at all during the entire cutting process.

[0039] The source of the initial support and resistance benchmarks is: After initial fixation is completed and before laser cutting begins, the internal cylinder air pressure of each activated support clamping unit is accurately read, and the read air pressure value is recorded as the initial support pressure reference for that support point.

[0040] In this embodiment, the initial support pressure reference is obtained through a direct physical quantity measurement process. Once all selected support clamping units extend and stably contact the workpiece according to the interference-free fixing scheme (i.e., after initial fixing is completed and before the laser cutting command is issued), the controller precisely reads the cylinder pressure inside each activated unit via pressure sensors connected to the air circuit of each micro-cylinder 221. This cylinder pressure value can be converted into the support force applied to the workpiece by the unit, directly reflecting the force required by the unit to maintain the current support height and support the local weight of the workpiece. The controller records this read pressure value digitally and binds it to the corresponding support unit position, storing it as the initial support pressure reference for that support point. This reference data provides a clear, representative starting point for subsequent dynamic instability monitoring, indicating a stable state.

[0041] The steps to determine whether a workpiece has experienced unstable deformation include: Calculate the difference between the real-time support pressure data and the initial support pressure benchmark to obtain the pressure deviation. The absolute value of the pressure deviation and the rate of change of the pressure deviation per unit time are weighted and summed to generate a deformation trend characteristic value. The deformation trend characteristic value is compared with the preset dynamic instability safety threshold, wherein the dynamic instability safety threshold is a safety limit value preset according to the processing material, plate thickness and cutting process parameters. Weighting coefficient and This can be set as follows: For materials with high rigidity, the value can be appropriately reduced. The value can be increased for easily deformable thin plates; The values ​​are determined to improve the system's sensitivity to rapid deformation. These values ​​can be determined through prior stability testing and data analysis on different materials, forming a parameter database for automatic recall by the controller. The dynamic instability safety threshold can be set by pre-calibration and table lookup. By conducting experiments on different combinations of materials, thicknesses, and process parameters such as cutting speed and power, the deformation trend characteristics under stable conditions are recorded, and the critical value exceeding the stable range is used as the dynamic instability safety threshold under that combination and stored in the parameter table inside the controller; When the deformation trend characteristic value exceeds the dynamic instability safety threshold, the workpiece is determined to have undergone unstable deformation. When the deformation trend characteristic value does not exceed the dynamic instability safety threshold, it is determined that the workpiece has not undergone unstable deformation.

[0042] In this embodiment, the process of determining whether the workpiece has experienced unstable deformation is based on a derivation process using data trend analysis. During the cutting process, the controller continuously acquires real-time support pressure data for each support point. For each point, the controller calculates the difference between the current real-time pressure value and the previously stored initial support pressure benchmark; this difference is defined as the pressure deviation. This deviation alone is insufficient to predict instability, as slow, small-scale pressure changes may be normal. Therefore, the algorithm also calculates the rate of change of this pressure deviation per unit time; a rapidly increasing rate of change usually indicates accelerated deformation. To ensure the rigor of the physical meaning of the calculation, the controller combines the absolute value of the pressure deviation with its rate of change through a weighted summation calculation to generate a comprehensive index, namely, the deformation trend characteristic value. In this summation calculation, the rate of change is given a higher weighting coefficient, making it have a greater impact on the final result.

[0043] The calculation logic of this weighted summation is that the absolute value of the pressure deviation reflects the amount of current deformation, while its rate of change reflects the acceleration or trend of deformation; a rapidly increasing rate of change, even if the current deviation is still small, indicates that the workpiece is about to experience significant instability, and therefore requires higher attention. The inputs to this calculation process are real-time support pressure data and an initial support pressure baseline. The logical steps are as follows: Step 1: Calculate the difference between the real-time support pressure data and the initial support pressure benchmark to obtain the pressure deviation. Step 2: Calculate the rate of change of pressure deviation per unit time; Step 3: Weight the absolute value of the pressure deviation and the rate of change to generate a deformation trend characteristic value; The specific calculation method can be expressed by the following formula: ; in, The final generated deformation trend characteristic value is a dimensionless number; This is the absolute value of the pressure deviation, that is, the absolute value of the difference between the current real-time support pressure and the initial support pressure benchmark. For reference pressure, the average value of the initial support pressure benchmark is usually taken; unit of time The rate of change of the absolute value of the internal pressure deviation; As a reference rate of change, it is preset according to the material properties and is usually taken as 0.01-0.1 MPa / s; and The preset dimensionless weighting coefficients are usually set as follows: ,For example , Prioritize responses to rapid deformation.

[0044] By introducing reference values and Both terms of the formula are converted into dimensionless form, ensuring dimensional consistency while maintaining the clarity of physical meaning: the first term represents the relative magnitude of the deformation amplitude, and the second term represents the relative speed of the deformation rate.

[0045] Those skilled in the art can understand the weighting coefficient. , The specific value of the dynamic instability safety threshold can be adjusted and calibrated through a limited number of routine experiments, based on different processing materials, plate thicknesses, and cutting process parameters, to achieve suitable monitoring sensitivity. This is a conventional technical method in this field. This represents the weight of the influence of deformation amplitude on the characteristic value of deformation trend, while The weight representing the influence of deformation rate is usually set. > The numerical relationships are prioritized to respond to rapid deformation, ensuring that the system can respond quickly and sensitively to potential signs of instability.

[0046] After calculating the deformation trend characteristic value, the controller compares it with a preset dynamic instability safety threshold. This threshold is preset according to the mechanical properties and process requirements of different materials. If the deformation trend characteristic value of any support point exceeds this threshold, the system determines that the workpiece has undergone unstable deformation at that position and triggers the corresponding supplementary support action. Conversely, if the characteristic values ​​of all points are below the threshold, the workpiece is determined to be stable.

[0047] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A laser cutting device with an adaptive fixing structure, characterized in that, include: Machine tool base (100); An adaptive fixture table (200) is mounted on the machine tool base (100); The adaptive fixture stage (200) includes a grid support plate (210) and a support clamping unit array (220). The grid support plate (210) is fixed on the machine tool base (100), and an array of through holes is arranged on it; The support clamping unit array (220) is disposed below the grid support plate (210), and includes multiple support clamping units that can extend independently and pass through the array through holes; A three-dimensional vision system (300) is mounted above the machine tool base (100); The controller is electrically connected to the support clamping unit array (220) and the three-dimensional vision system (300); The controller is used to control the movement of the support clamping unit array (220) to form an interference-free fixation of the workpiece based on the three-dimensional digital model generated by the three-dimensional vision system (300) scanning the workpiece and the preset laser cutting path.

2. The laser cutting device with an adaptive fixing structure according to claim 1, characterized in that, Each of the aforementioned support clamping units includes: A miniature cylinder (221) has its cylinder body fixed to a mounting base plate; The piston rod (222) is vertically disposed inside the miniature cylinder (221); The support head (223) is connected to the top of the piston rod (222) and is used for flexible contact with the workpiece.

3. A laser cutting device with an adaptive fixing structure according to claim 2, characterized in that, An electromagnet is integrated within the support head (223) of a portion of the support clamping unit to form a clamping unit for generating an adsorption force on a magnetically conductive workpiece.

4. The laser cutting device with an adaptive fixing structure according to claim 1, characterized in that, The three-dimensional vision system (300) includes: The gantry frame (310) is movably mounted on the machine tool base (100); A scanning module (320) is mounted on the gantry frame (310) and can move along it; The scanning module (320) includes a structured light projector and an industrial camera.

5. A laser cutting method with an adaptive fixing structure, applied to the laser cutting apparatus with an adaptive fixing structure as described in claim 1, characterized in that, include: Drive the 3D vision system (300) to scan the workpiece to obtain 3D point cloud data; A three-dimensional digital model is constructed based on the three-dimensional point cloud data, wherein the three-dimensional digital model is used to characterize the three-dimensional contour and surface warpage of the workpiece; Retrieve preset laser cutting path data; Based on the three-dimensional digital model and the laser cutting path data, an interference-free fixing scheme is generated, wherein the interference-free fixing scheme is used to define the combination of the support and clamping units to be activated and their respective target motion parameters; The support clamping unit array (220) is controlled to execute the interference-free fixing scheme to complete the initial fixing of the workpiece; Record the support pressure of each activated support clamping unit after the initial fixing is completed, and use it as the initial support pressure reference. During the laser cutting process, the support pressure of each activated support clamping unit is monitored in real time to generate real-time support pressure data; Based on the comparison between the real-time support pressure data and the initial support pressure benchmark, it is determined whether the workpiece has undergone unstable deformation. When it is determined that the workpiece has undergone unstable deformation, the currently inactive support and clamping unit is controlled to perform a supplementary support action; If it is determined that the workpiece has not undergone unstable deformation, the current laser cutting process is maintained.

6. The laser cutting method with an adaptive fixing structure according to claim 5, characterized in that, The steps for generating the interference-free fixation scheme include: The laser cutting path data is superimposed onto the three-dimensional digital model; Based on the surface warpage of the workpiece, the support clamping unit located in the low-lying area below the workpiece is preferentially selected as the support point. For each selected support clamping unit, the workpiece bottom surface height coordinate value at the corresponding position of the unit is extracted from the three-dimensional digital model, and the difference between the height coordinate value and the reference plane height of the grid support plate is used as the target extension height of the support clamping unit. In the area at the edge of the workpiece model and away from the cutting path, a clamping unit with an electromagnet is selected as the clamping point. Simulate the movement trajectory of the laser head and check whether it interferes with any selected support or clamping unit; If interference occurs, the conflicting unit is replaced and the process is repeated until a final interference-free fixation solution is obtained.

7. A laser cutting method with an adaptive fixing structure according to claim 5, characterized in that, The source of the initial support pressure benchmark is: After the initial fixing is completed and before the laser cutting begins, the internal cylinder air pressure of each activated support clamping unit is accurately read, and the reading value of the air pressure is recorded as the initial support pressure reference for that support point.

8. A laser cutting method with an adaptive fixing structure according to claim 5, characterized in that, The step of determining whether the workpiece has undergone unstable deformation includes: Calculate the difference between the real-time support pressure data and the initial support pressure benchmark to obtain the pressure deviation. The absolute value of the pressure deviation and the rate of change of the pressure deviation per unit time are weighted and summed to generate a deformation trend characteristic value. The deformation trend characteristic value is compared with a preset dynamic instability safety threshold, wherein the dynamic instability safety threshold is a safety limit value preset according to the processing material, plate thickness and cutting process parameters; When the deformation trend characteristic value exceeds the dynamic instability safety threshold, it is determined that the workpiece has undergone unstable deformation. When the deformation trend characteristic value does not exceed the dynamic instability safety threshold, it is determined that the workpiece has not undergone unstable deformation.

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