Process control method and system for laser cutting of optical element

Abstract

According to the optical element laser cutting process control method and system, the problems of microcracks and edge breakage caused by heat accumulation in laser cutting are solved through real-time monitoring and dynamic compensation of thermal field deviation of a turning area; the method comprises the steps that a turning area in a cutting path is recognized in advance, and key points are marked; during cutting, thermal field distribution is monitored in real time, and the heat center offset and direction are obtained; the laser power and the cutting speed are dynamically adjusted according to the offset, and the light spot position compensation offset is synchronously adjusted according to the offset direction and the offset; after passing through the turning center point, symmetrically recovering the laser parameters to initial values; the system comprises a path analysis module, a thermal field monitoring module, a control adjustment module, a parameter recovery module and an execution module, and closed-loop control of the method can be achieved through the system. Thermal damage of laser cutting in the turning area can be effectively restrained, the cutting quality consistency before and after the turning area is kept, and the machining yield is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of laser cutting, and particularly to a process control method and system for laser cutting of optical elements. Background Art

[0002] The high-precision laser cutting technology of optical elements is one of the core processes in the optoelectronic manufacturing field. Especially at present when miniaturized devices such as smartphone lenses and AR / VR optical modules are developing rapidly, more stringent requirements are put forward for the processing quality of brittle materials such as ultra-thin glass and sapphire.

[0003] The industry currently generally uses ultraviolet picosecond lasers for precision cutting, but still faces severe challenges when dealing with complex contours - when the cutting path has sharp turns or acute angle turns, due to the extended residence time of the laser beam at the corner and asymmetric heat diffusion, two key problems will occur: excessive heat accumulation forms a local high-temperature area inside the bend, and at the same time the heat center point continuously shifts towards the inside of the bend; this imbalance in heat distribution will generate a significant lateral temperature gradient, which will in turn induce defects such as microcracks and edge chipping, reducing the fracture strength of the optical element and directly affecting the finished product quality of the optical element.

[0004] The existing technologies mainly adopt two solutions: one is to reduce the heat input by presetting to lower the laser power, but the fixed-amplitude power adjustment cannot adapt to the turning areas with different curvatures; the other is to introduce a pause cooling time at the turning point, which will significantly reduce the processing efficiency and produce obvious tool marks. Neither of these two methods can fundamentally solve the problem of dynamic imbalance of the heat field. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the problem that the dynamic imbalance of the heat field in the turning area of laser cutting cannot be fundamentally solved in the prior art, and provide a process control method for laser cutting of optical elements, which can effectively suppress the microcracks and edge chipping caused by heat accumulation by real-time monitoring and dynamically compensating the offset of the heat center point in the turning area, and at the same time introduce a parameter restoration mechanism to ensure the consistency of laser cutting before and after dynamic compensation in the turning area.

[0006] To solve the above technical problem, the present invention provides a process control method for laser cutting of optical elements, including the following steps: Before cutting, obtain all the curvature change amounts in the laser cutting path, identify all the turning areas on the cutting path according to the curvature change amounts, and determine the starting point, center point and ending point of each turning area; During cutting, when cutting reaches the starting point, obtain the lateral temperature distribution in the laser action area in real time, and identify the offset amount and offset direction of the heat center point relative to the laser spot center according to the lateral temperature distribution; Dynamically adjust the laser power and cutting speed according to the offset, so that the laser power gradually decreases as the offset increases, and the cutting speed gradually decreases as the offset increases; Adjust the laser spot position according to the offset direction and offset amount to compensate for the offset of the heat center; When the cutting reaches the center point, according to the dynamic change amount of the laser power, cutting speed, and laser spot position between the starting point and the center point, adjust the laser power, cutting speed, and laser spot position in equal amplitude and in the opposite direction, so that when the cutting reaches the end point, the laser power, cutting speed, and laser spot position all return to the initial parameters.

[0007] In an embodiment of the present invention, identifying all turning regions on the cutting path according to the curvature change amount includes the following steps: Divide the continuous cutting path into path segments of equal length, and calculate the curvature change amount of each path segment. The curvature change amount is obtained by measuring the angle difference between the tangent directions at both ends of the path segment; When the curvature change amounts of three consecutive path segments all exceed the reference curvature change amount, determine that this region is a turning region; Extend from the turning region to both sides until a path segment whose curvature change amount is lower than the reference curvature change amount for the first time is found, and mark the endpoints of this path segment as the starting point or the ending point of the turning region; After determining that the two endpoints of the turning region are the starting point and the ending point respectively, determine the midpoint of the path between the starting point and the ending point as the center point.

[0008] In an embodiment of the present invention, the reference curvature change amount is determined through the following steps: Conduct a standard straight-line cutting test on the target optical element material, and record the natural curvature fluctuation range during the cutting process; Based on the results of the standard straight-line cutting test, select the maximum allowable curvature change amount when the cutting quality meets the standard as the initial reference value; During the actual cutting process, dynamically correct the initial reference value according to the real-time monitored cutting quality feedback, and the correction amplitude does not exceed ±20% of the initial reference value; For cutting regions with different thicknesses, adjust the reference curvature change amount according to the thickness ratio. For every 0.1 mm increase in thickness, the reference value is correspondingly increased by 5%.

[0009] In an embodiment of the present invention, taking the starting point of the cutting path as the coordinate origin, establish a plane rectangular coordinate system, represent the starting point, center point, and ending point in the coordinate system, and call the coordinates of each feature point in real time during the cutting process to guide the adjustment of process parameters.

[0010] In an embodiment of the present invention, identifying the offset and offset direction of the heat center point relative to the laser spot center according to the lateral temperature distribution includes the following steps: Taking the theoretical center of the laser spot as the reference point, dividing the detection area into four quadrants, using an infrared thermal imager to sequentially scan the temperature distribution of each quadrant, and recording the highest temperature value and the corresponding coordinate position in each quadrant; Comparing the highest temperature values of the four quadrants, determining the dominant quadrant with the most concentrated temperature distribution. In this dominant quadrant, selecting the area with the largest temperature gradient change as the high-temperature core area, and calculating the geometric center of all high-temperature points in the high-temperature core area as the actual heat center point; Connecting the theoretical center of the laser spot and the actual heat center point to form a reference line, measuring the length of the reference line as the offset, and using the cutting forward direction as the reference axis, measuring the angle between the reference line and the reference axis as the offset direction.

[0011] In an embodiment of the present invention, dynamically adjusting the laser power according to the offset includes the following steps: Dividing the detected offset into several levels, with each level corresponding to a different power adjustment amplitude; Determining the base power value according to the path characteristics of the current cutting position, where the base power value is the minimum power value that meets the quality standard during straight cutting; When the offset is within the first level range, keep the current power unchanged; When the offset is within the second level range, gradually reduce the power according to the first adjustment amplitude, where the first adjustment amplitude is 3% - 5% of the current power value; When the offset is within the third level range, quickly reduce the power according to the second adjustment amplitude, where the second adjustment amplitude is 6% - 8% of the current power value; Power lower limit protection: Setting the minimum power threshold to ensure the continuous and stable progress of the cutting process.

[0012] In an embodiment of the present invention, dynamically adjusting the cutting speed according to the offset includes the following steps: Determining the speed adjustable range according to the material type and thickness; Establishing an offset-speed mapping relationship, including: a small offset range corresponding to a 5% - 10% reduction in speed; a medium offset range corresponding to an 11% - 20% reduction in speed; a large offset range corresponding to a 21% - 30% reduction in speed; Setting the upper limit of the speed change rate to 5% per second, and adopting a progressive transition when switching between adjacent offset ranges; Real-time monitoring the change in the cutting surface quality, and dynamically optimizing the offset-speed mapping relationship according to the cutting effect.

[0013] In one embodiment of the present invention, while adjusting the position of the laser spot according to the offset direction, an auxiliary gas is introduced to adjust the heat offset. According to the offset compensation direction of the laser spot, the injection angle of the auxiliary gas nozzle is synchronously adjusted so that the center line of the gas flow field is aligned with the midpoint line position of the compensated laser spot.

[0014] In one embodiment of the present invention, it further includes: Real-time monitor the amplitude and frequency of energy fluctuations during the cutting process. When the amplitude of energy fluctuations exceeds 30% of the normal range and lasts for more than 50 ms, it is determined as an abnormal situation; Immediately freeze the current laser power and cutting speed parameters, and keep the position of the laser spot unchanged in the current compensation state; Analyze the change trend of the temperature distribution in the recent 10 sampling periods, detect whether there is a sudden change in the moving trajectory of the heat center point, and check whether the optical path system is interfered; If it is diagnosed as an instantaneous interference, continue cutting with the current parameters. If it is diagnosed as a continuous abnormality, start a progressive parameter rollback mechanism; Gradually restore the laser power by 50% of the original adjustment amount. The cutting speed is synchronously adjusted according to the power recovery ratio, and the spot position is restored last to ensure the stability of the thermal field. After completion, re-establish the normal adjustment mechanism.

[0015] The present invention also discloses a process control system for laser cutting of optical elements, including: A path analysis module, used to obtain all the curvature change amounts in the laser cutting path, identify all the turning areas on the cutting path according to the curvature change amounts, and determine the starting point, center point, and ending point of each turning area; A thermal field monitoring module, used to obtain the lateral temperature distribution of the laser action area in real time during the cutting process. When the cutting reaches the starting point, identify the offset amount and offset direction of the heat center point relative to the center of the laser spot; A control adjustment module, connected to the thermal field monitoring module, for: Dynamically adjust the laser power and cutting speed according to the offset amount, so that the laser power gradually decreases as the offset amount increases, and the cutting speed gradually decreases as the offset amount increases; Adjust the position of the laser spot according to the offset direction and offset amount to compensate for the offset of the heat center; A parameter recovery module, used to, when the cutting reaches the center point, adjust the laser power, cutting speed, and laser spot position in equal amplitude and in the opposite direction according to the dynamic change amounts of the laser power, cutting speed, and laser spot position between the starting point and the center point, so that when the cutting reaches the ending point, the laser power, cutting speed, and laser spot position all return to the initial parameters; The execution module is used to execute the instructions of the control and adjustment module and the parameter recovery module to complete the laser cutting operation.

[0016] The above technical solution of the present invention has the following advantages over the prior art: The process control method for laser cutting of optical components described in the present invention uses the thermal center offset as the key control mechanism. When the cutting enters the turning zone, the lateral temperature field distribution at the cutting front is captured in real time, and the thermal center offset, including the offset amount and direction, is calculated. This essentially reflects the severity of the thermal field imbalance. Based on this data, three key parameters are synchronously adjusted: The laser power and cutting speed are controlled to decrease in proportion to the offset, ensuring sufficient energy to complete the cutting while avoiding heat accumulation. According to the offset direction and offset amount, the laser spot position is adjusted to move in the opposite direction of the offset, and the physical influence of the thermal field offset is directly offset through active compensation; On the basis of the above-mentioned dynamic regulation, the present invention also introduces a parameter recovery mechanism to control the laser cutting to symmetrically restore the parameters according to the amplitude of reduction in the first half after passing the center point of the turning area. This mirror adjustment method ensures a smooth transition of thermal effects and achieves consistency of laser cutting before and after the turning area, avoiding insufficient cutting after the turning area due to reducing the laser power and cutting speed, and also avoiding secondary thermal shock caused by instantaneously increasing the laser power and cutting speed after the cutting of the turning area is completed. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 is a flowchart of the process control method for laser cutting of optical elements of the present invention; Figure 2 This is a flowchart of the steps of identifying all turning areas on the cutting path according to the curvature change of the present invention; Figure 3 is a flow chart of the steps for determining the reference curvature change amount of the present invention; Figure 4 This is a flow chart of the steps of identifying the offset amount and offset direction of the heat center relative to the laser spot center based on the transverse temperature distribution of the present invention; Figure 5 is a flow chart of the steps of dynamically adjusting the laser power according to the offset of the present invention; Figure 6 is a flow chart of the steps of dynamically adjusting the cutting speed according to the offset amount of the present invention; Figure 7 is a flowchart of the steps of the emergency method of the present invention; Figure 8 It is a structural block diagram of the process control system for laser cutting of the optical element of the present invention. Specific embodiments

[0018] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, so that those skilled in the art can better understand the present invention and be able to implement it, but the illustrated embodiments are not intended to limit the present invention.

[0019] Refer to Figure 1 As shown, a process control method for laser cutting of an optical element of the present invention includes the following steps: S10. Before cutting, obtain all the curvature change amounts in the laser cutting path, identify all the turning regions on the cutting path according to the curvature change amounts, and determine the starting point, center point and ending point of each turning region; In this embodiment, by pre-analyzing the geometric characteristics of the cutting path, the turning regions that need special treatment are accurately identified, and the key position points for regulation are determined. The purpose of doing this is to determine accurate position information for subsequent real-time regulation, ensure that the thermal field regulation can fully correspond to the actual geometric turning, avoid the blindness of regulation, enable subsequent temperature monitoring and parameter adjustment to accurately act on the regions that actually need to be controlled, and improve the response accuracy of the entire process control.

[0020] S20. During the cutting process, when the cutting reaches the starting point, obtain the lateral temperature distribution in the laser action region in real time, and identify the offset amount and offset direction of the heat center point relative to the laser spot center according to the lateral temperature distribution; In the specific implementation process, an infrared thermal imager can be used to capture the temperature field information in real time and calculate the offset of the heat center, which can quantify the specific degree and direction of the thermal field imbalance and provide accurate input parameters for subsequent dynamic adjustment.

[0021] S30. Dynamically adjust the laser power and cutting speed according to the offset amount, so that the laser power gradually decreases as the offset amount increases, and the cutting speed gradually decreases as the offset amount increases; In this embodiment, by establishing a proportional relationship between the offset amount and the process parameters, precise control of the laser energy input is achieved. The energy input is adjusted according to the actual thermal field imbalance degree, which not only ensures the continuity of cutting, but also effectively suppresses heat accumulation. Through the dynamic balance control of energy input and heat load, the problem that traditional fixed-value adjustment cannot adapt to different curvature turns is avoided, and the problem that the laser cutting parameters are inaccurately adjusted according to the bending angle in the prior art is further solved, significantly reducing the risk of thermal damage.

[0022] S40. Adjust the laser spot position according to the offset direction and offset amount to compensate for the offset of the heat center; In the specific implementation process, the present invention also actively adjusts the position of the light spot to directly intervene in the distribution state of the thermal field. Adjusting the position of the light spot can directly offset the influence of the thermal field offset physically, improving the symmetry of the thermal distribution.

[0023] Furthermore, in the above steps, due to the offset of the heat center resulting in excessive local temperature, the heat accumulation is suppressed by reducing the laser power and cutting speed. However, this adjustment will form process parameters different from those of the straight line segment in the turning area. After laser cutting the turning area, different process parameters will lead to different cutting qualities before and after the turning area. To solve this problem, the present invention also adopts a parameter recovery method of mirror symmetry: S50. When the cutting reaches the center point, according to the dynamic change amount of the laser power, cutting speed, and laser spot position between the starting point and the center point, the laser power, cutting speed, and laser spot position are adjusted in equal amplitude and in the reverse direction, so that when the cutting reaches the end point, the laser power, cutting speed, and laser spot position all return to the initial parameters; In this embodiment, based on the reduction amplitude of the first half - process parameters, equal - amplitude reverse adjustment is performed in the second half - process to ensure that the energy input in the turning area shows symmetric distribution, avoiding secondary thermal shock or cutting quality fluctuations caused by parameter mutations; realizing a smooth transition of process conditions, eliminating the risk of thermal damage caused by parameter reduction in the first half - process, and ensuring the process stability during the recovery in the second half - process, making the cutting quality of the entire turning area consistent with that of the straight line segment. This symmetric recovery mechanism is particularly suitable for materials sensitive to thermal shock such as ultra - thin optical glass, and can maintain the processing efficiency while controlling the thermal influence.

[0024] Refer to Figure 2 As shown, in this embodiment, the continuous cutting path is discretized, achieving precise capture of the turning features in the complex path, providing an accurate geometric reference for subsequent temperature control and parameter adjustment. The specific implementation process includes: S11. Path feature analysis: The continuous cutting path is divided into path segments of equal length, and the curvature change amount of each path segment is calculated. The curvature change amount is obtained by measuring the angle difference between the tangent directions at both ends of the path segment; S12. Turning area determination: When the curvature change amounts of three consecutive path segments all exceed the reference curvature change amount, this area is determined as the turning area; S13. Turning area boundary determination: Extend from the turning area to both sides until a path segment with a curvature change amount lower than the reference curvature change amount for the first time is found, and the endpoints of this path segment are marked as the starting point or the ending point of the turning area; S14. Turning area center point determination: After determining the two endpoints of the turning area as the starting point and the ending point respectively, the mid - point of the path between the starting point and the ending point is determined as the center point.

[0025] From the perspective of technical effects, the recognition method of this embodiment can accurately capture the turning features of various complex shapes through multi-level criteria and boundary expansion mechanisms. Its discretization processing method is particularly suitable for the digital control requirements of CNC systems, while the calculation method based on the tangent angle difference greatly reduces the resource consumption of real-time calculation and can achieve fast response while maintaining high precision. Each step is closely linked, from path discretization to curvature calculation, from region determination to boundary confirmation, and finally key point positioning is completed, forming a complete and reliable turning region recognition system, laying a solid foundation for the subsequent dynamic adjustment of process parameters.

[0026] Referring to Figure 3 As shown, in order to further improve the above technical solution and realize the application of the above solution in the process, this embodiment further discloses how to determine the reference curvature change amount, including: S12(1): Standard straight-line cutting test: Conduct a standard straight-line cutting test on the target optical element material and record the natural curvature fluctuation range during the cutting process. This basic test excludes the influence of equipment errors and material inhomogeneity and provides an objective basis for setting the reference value; S12(2): Determine the initial reference value: Based on the results of the standard straight-line cutting test, select the maximum allowable curvature change amount when the cutting quality meets the standard as the initial reference value, ensuring that the true turning features are retained to the greatest extent while ensuring the cutting quality; S12(3): Dynamic optimization adjustment: During the actual cutting process, dynamically correct the initial reference value according to the real-time monitored cutting quality feedback, and the correction amplitude does not exceed ±20% of the initial reference value. This adaptive ability effectively copes with uncertain factors in the processing process, such as material batch differences or environmental temperature fluctuations, etc. S12(4): Thickness differential adjustment: For cutting areas with different thicknesses, adjust the reference curvature change amount according to the thickness ratio, and for every 0.1 mm increase in thickness, the reference value is correspondingly increased by 5%. This on-demand adjustment method accurately reflects the influence law of material thickness on cutting deformation characteristics.

[0027] In this embodiment, this method for determining the reference value combines experimental testing and theoretical calculation, ensuring both the objectivity and practicality of the parameters. Among them, the dynamic correction mechanism endows the ability to adapt to complex working conditions, while the adjustment for thickness changes reflects the scientific nature of parameter setting and the applicability of the method to different material products.

[0028] Specifically, from basic tests to practical applications, and from static settings to dynamic optimization, a complete parameter determination system has been formed, providing reliable technical support for the recognition of the transition region, ensuring that the true transition characteristics can be accurately recognized under various working conditions, avoiding misjudgment or missed detection, not only improving the accuracy of transition recognition, but also providing guarantee for the stability of the entire cutting process, enabling subsequent temperature control and parameter adjustment to be based on accurate geometric features.

[0029] In this embodiment, in order to digitally connect the determined geometric features (starting point, center point, ending point) with process control, by establishing a standardized coordinate system, the starting point, center point, and ending point of the transition region are transformed into quantifiable coordinate parameters, providing a spatial reference for the precise control of the entire cutting process. Specifically, the design of establishing a plane rectangular coordinate system with the starting point of the cutting path as the coordinate origin not only conforms to the conventional operation logic of the numerical control machining system, but also ensures the uniqueness and stability of the coordinate system, avoiding positioning errors caused by changes in the reference system. The method of representing the feature points with coordinates is essentially to transform the recognized geometric features into digital instructions that can be recognized by the machine. This digital conversion enables subsequent process parameter adjustment to establish an accurate correspondence with the spatial position. The mechanism of real-time calling of coordinate data during the cutting process ensures the strict synchronization of process control and geometric position. This spatio-temporal consistency is particularly crucial for the precise processing of the transition region.

[0030] In this embodiment, this method of coordinate processing eliminates the reference differences between different processes by establishing a unified spatial reference system; binds the feature point coordinates with process parameters to achieve precise control based on position; and the real-time calling mechanism ensures the timeliness of control. From the establishment of the coordinate system to the determination of coordinates and then to data calling, a complete spatial positioning control chain is formed, enabling the recognized transition features to be accurately transformed into control instructions to guide the precise adjustment of parameters such as laser power and cutting speed.

[0031] This control method based on the coordinate system not only improves the accuracy of process execution, but also enhances the repeatability of the method, providing reliable guarantee for the stable machining of complex paths, enabling temperature control and parameter compensation to be accurately implemented at the correct spatial position.

[0032] Refer to Figure 4 As shown, in this embodiment, in order to accurately quantify the thermal field asymmetry during the laser cutting process, a method for identifying the offset of the thermal field center of gravity is provided, including: S21. Temperature field partition scanning: Design of dividing four quadrants with the theoretical center of the laser spot as the reference, creatively transforming the complex thermal field distribution problem into a structured data analysis problem. This partition processing method not only improves the detection efficiency but also enhances the reliability of the results through comparative analysis between quadrants; Use an infrared thermal imager to scan the temperature distribution of each quadrant in turn and record the maximum temperature value and its position. This method not only ensures the comprehensiveness of data collection but also reduces the data processing complexity through key feature extraction.

[0033] S22. Heat center positioning: Design of determining the dominant quadrant by comparing the maximum temperature values of the four quadrants and selecting the area with the largest temperature gradient change in the dominant quadrant as the high-temperature core area, which utilizes the physical feature of temperature gradient to identify the true thermal influence center and avoids misjudgment that may be caused by simply relying on absolute temperature values; Further, calculate the geometric center of the high-temperature core area as the actual heat center point, effectively eliminating the interference of local abnormal points through multi-point averaging.

[0034] S23. Offset parameter determination: The operation of connecting the theoretical center and the actual center to form a reference line transforms the abstract thermal field offset into an intuitive geometric quantity, facilitating subsequent parameter adjustment. Measuring the length of the reference line as the offset amount can reflect the degree of thermal field imbalance, while measuring the angle between the reference line and the reference axis with the cutting forward direction as the reference axis as the offset direction can accurately capture the spatial orientation of the offset.

[0035] In this embodiment, this thermal field analysis method significantly improves the accuracy of heat center positioning through structured partitioning and gradient feature recognition. The design of transforming the temperature distribution into geometric parameters forms a rigorous thermal field detection chain from area division to data collection, from feature analysis to parameter calculation, enabling thermal field regulation to be based on precise quantification, ensuring that the adjustment of parameters such as laser power and cutting speed can accurately correspond to the actual thermal distribution state, thereby effectively improving the cutting quality in the turning area.

[0036] Refer to Figure 5 As shown, in order to further guide the application in the process, the present invention also discloses a preferred process for dynamically adjusting the laser power according to the offset amount, including: S301. Offset amount grading: Divide the detected offset amount into several levels, and each level corresponds to a different power adjustment amplitude, transforming the continuous physical quantity change into a discrete control strategy, so that the power adjustment can accurately match different degrees of offset conditions.

[0037] S302. Power reference setting: Determine the base power value according to the path characteristics of the current cutting position. The base power value is the minimum power value that can achieve qualified quality during straight-line cutting, fully considering the differences in energy requirements for different geometries. This position-based energy reference setting ensures the rationality of power adjustment.

[0038] S303. Power adjustment execution: When the offset is within the first-level range, in actual processes, the first-level range can be quantified as 0.1 mm - 0.3 mm according to different optical elements. An offset within this range does not affect the quality of the product. Therefore, the strategy of keeping the laser power unchanged avoids overreacting to minor fluctuations and improves process stability. When the offset is within the second-level range, in actual processes, the second-level range can be quantified as 0.3 mm - 0.6 mm according to different optical elements. Gradually reduce the laser power by 3% - 5% to achieve precise compensation for moderate thermal offsets. This progressive adjustment not only ensures the timeliness of thermal control but also avoids cutting instability caused by sudden power changes. When the offset is within the third-level range, in actual processes, the third-level range can be quantified as greater than 0.6 mm according to different optical elements. Rapidly reduce the laser power by 6% - 8% to promptly suppress the risk of severe heat accumulation. This hierarchical response mechanism improves the adaptability to thermal offsets of different severities.

[0039] S304. Power lower limit protection: Set the minimum power threshold to ensure the continuous and stable progress of the cutting process, essentially preventing cutting interruptions caused by too low power and providing reliable guarantee for the process.

[0040] In this embodiment, this hierarchical power adjustment method realizes the organic combination of the thermodynamic process and process control by establishing an accurate correspondence between the offset and power changes; the base power setting based on path characteristics ensures the rationality of energy input; and the multi-level response mechanism endows it with the adaptability to different working conditions.

[0041] Specifically, from offset grading to power reference determination, from hierarchical adjustment to safety protection, a complete power control chain is formed, enabling the thermal field regulation to be achieved through precise power matching and ensuring that the laser energy input always maintains a dynamic balance with the thermal load of the material.

[0042] Similarly, referring to Figure 6 as shown, the present invention also discloses a preferred process for dynamically adjusting the cutting speed according to the offset, including: S311. Division of speed adjustment range: Determine the adjustable speed range according to the material type and thickness. First, consider the differences in the sensitivity of different materials to heat input. By presetting a reasonable speed adjustment range, a safety margin is provided for subsequent dynamic adjustment. This parameter setting based on material characteristics can effectively prevent cutting quality problems caused by improper speed adjustment.

[0043] S312. Establish the offset - speed mapping relationship: Set the small offset range (0.1 - 0.3 mm) corresponding to a 5% - 10% speed reduction, the medium offset range (0.3 - 0.5 mm) corresponding to an 11% - 20% speed reduction, and the large offset range (>0.5 mm) corresponding to a 21% - 30% speed reduction. This hierarchical mapping design enables the speed adjustment to precisely match different degrees of offset. Specifically, the offset - speed mapping relationship is determined through experiments, achieving a balance between heat input and material removal rate while ensuring the cutting quality of the product.

[0044] S313. Speed adjustment control: Set an upper limit of 5% per second for the speed change rate. Use a progressive transition when switching between adjacent offset ranges. This measure effectively prevents cutting instability caused by sudden speed changes. The progressive transition ensures the smooth change of process parameters and avoids cutting quality fluctuations caused by parameter jumps.

[0045] S314. Dynamically optimize the mapping relationship: A closed - loop control mechanism that monitors the quality change of the cutting surface in real time and dynamically optimizes the offset - speed mapping relationship according to the cutting effect endows it with the ability of self - learning and optimization. By continuously fine - tuning control parameters through quality feedback, it can adapt to the characteristic differences of different batches of materials and changes in the processing environment.

[0046] In this embodiment, this speed adjustment method realizes the precise matching of process parameters and thermodynamic states by establishing an accurate physical quantity mapping relationship; the limitation of the speed change rate ensures process stability; and the real - time optimization mechanism endows it with the ability of continuous improvement.

[0047] Specifically, from parameter range setting to mapping relationship establishment, from change rate control to real - time optimization, a complete speed control system is formed, enabling heat field management to be achieved through intelligent speed adjustment and ensuring that the cutting process is always in the best thermodynamic equilibrium state.

[0048] In the laser cutting process, the assist gas not only undertakes the basic function of removing molten materials, but its flow characteristics also play an important role in regulating the temperature distribution in the cutting area. In the prior art, the application position of the assist gas is fixed. However, in this embodiment, since the position of the laser spot is adjusted in real time, it is also necessary to adjust the application position of the assist gas according to the position change of the laser spot to ensure that the center line of the gas flow field is accurately aligned with the midpoint line of the compensated laser spot, so that the assist gas can act on the thermal offset area most effectively.

[0049] Specifically, when it is detected that the heat center point deviates, first determine the direction and distance that the laser spot needs to be compensated, and then drive the gas nozzle to make corresponding angular adjustments. This linkage control ensures that the gas jet always points to the area that most needs heat dissipation. On the one hand, it enhances the slag discharge efficiency and prevents secondary heat conduction; on the other hand, it realizes targeted cooling of the high-temperature area through the directional air flow, effectively balancing the temperature distribution.

[0050] This collaborative adjustment method significantly improves the thermal compensation effect through the precise matching of gas flow and the position of the laser spot. From offset detection to spot compensation, from nozzle adjustment to flow field optimization, a complete thermal management closed-loop is formed, enabling thermal field control to be achieved through multiple physical means, and significantly improving the cutting quality in the transition area.

[0051] During the laser cutting process of precision optical components, due to factors such as uneven microstructures of materials, environmental vibrations, or instantaneous equipment failures, special situations such as abnormal energy fluctuations may occur. These sudden situations will have a serious impact on the cutting quality. Therefore, this embodiment also provides an emergency treatment method. Refer to Figure 7 As shown, it includes: S61. Abnormal situation identification: Real-time monitor the amplitude and frequency of energy fluctuations during the cutting process. When it is detected that the fluctuation amplitude exceeds 30% of the normal range and the duration reaches 50 ms, it is determined as an abnormal situation. The design of dual criteria not only ensures the sensitivity of abnormal identification but also avoids false alarms. S62. Parameter stabilization processing: Immediately freezing the operation of the current process parameters can effectively prevent the abnormal situation from deteriorating further, and buying precious time for diagnosis. Keeping the position of the laser spot unchanged maintains the relative stability of the thermal field.

[0052] S63. Abnormal cause diagnosis: By analyzing the temperature distribution change trend in the recent 10 sampling periods, detecting the moving trajectory of the heat center point, and checking the state of the optical path system, this multi-angle diagnosis method can accurately distinguish instantaneous interference and continuous abnormalities.

[0053] S64. Recovery strategy selection: For instantaneous interference, the strategy of maintaining the current parameters and continuing cutting is selected, which reflects the fault tolerance for short-term fluctuations; for continuous anomalies, a progressive parameter rollback mechanism is initiated. This hierarchical processing method ensures both safety and production efficiency.

[0054] S65. Safe recovery: The design of gradually restoring the laser power by 50% of the original adjustment amount realizes a smooth transition of energy. The cutting speed is adjusted synchronously according to the power recovery ratio, maintaining the coordination of process parameters. Finally, restoring the spot position ensures the ultimate stability of the thermal field.

[0055] The entire anomaly handling mechanism, from real-time monitoring to rapid response, from precise diagnosis to hierarchical processing, and finally achieving smooth recovery, forms a complete emergency management closed-loop, enabling the process method of this embodiment to still ensure the processing quality in the face of emergencies.

[0056] Refer to Figure 8 As shown, to implement the above method, the present invention also discloses a process control system for laser cutting of optical elements, including: A path analysis module for obtaining all the curvature change amounts in the laser cutting path, identifying all the turning regions on the cutting path according to the curvature change amounts, and determining the starting point, center point, and ending point of each turning region; A thermal field monitoring module for obtaining the lateral temperature distribution of the laser action region in real time during cutting, and when cutting reaches the starting point, identifying the offset amount and offset direction of the heat center point relative to the laser spot center; A control and adjustment module connected to the thermal field monitoring module for: Dynamically adjusting the laser power and cutting speed according to the offset amount, so that the laser power gradually decreases as the offset amount increases, and the cutting speed gradually decreases as the offset amount increases; Adjusting the laser spot position according to the offset direction and offset amount to compensate for the offset of the heat center; A parameter recovery module for, when cutting reaches the center point, equally adjusting the laser power, cutting speed, and laser spot position in the opposite direction according to the dynamic change amounts of the laser power, cutting speed, and laser spot position between the starting point and the center point, so that when cutting reaches the ending point, the laser power, cutting speed, and laser spot position all return to the initial parameters; An execution module for executing the instructions of the control and adjustment module and the parameter recovery module to complete the laser cutting operation.

[0057] Using the process control system for laser cutting of optical elements in this embodiment can implement the process control method for laser cutting of optical elements in the above embodiment. The specific implementation process refers to the description of the above embodiment and will not be repeated here.

[0058] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0059] The present application is described with reference to the flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one or more of the processes or multiple processes and / or blocks Figure 1 one or more of the blocks or multiple blocks.

[0060] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory generate a manufactured article including instruction means, and the instruction means implement the functions specified in Figure 1 one or more of the processes or multiple processes and / or blocks Figure 1 one or more of the blocks or multiple blocks.

[0061] These computer program instructions can also be loaded onto a computer or other programmable data processing device, so that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one or more of the processes or multiple processes and / or blocks Figure 1 one or more of the blocks or multiple blocks.

[0062] Obviously, the above embodiments are only examples given for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims

1. A process control method for laser cutting of optical elements, characterized in that: Including the following steps: Before cutting, obtain all the curvature change amounts in the laser cutting path, identify all the turning regions on the cutting path according to the curvature change amounts, and determine the starting point, center point and ending point of each turning region; During the cutting process, when the cutting reaches the starting point, obtain the lateral temperature distribution of the laser action area in real time, and identify the offset amount and offset direction of the heat center point relative to the laser spot center according to the lateral temperature distribution; Dynamically adjust the laser power and cutting speed according to the offset amount, so that the laser power gradually decreases as the offset amount increases, and the cutting speed gradually decreases as the offset amount increases; Adjust the laser spot position according to the offset direction and offset amount to compensate for the offset of the heat center; When the cutting reaches the center point, adjust the laser power, cutting speed and laser spot position in an equal amplitude and reverse manner according to the dynamic change amounts of the laser power, cutting speed and laser spot position between the starting point and the center point, so that when the cutting reaches the ending point, the laser power, cutting speed and laser spot position all return to the initial parameters.

2. The process control method for laser cutting of an optical element according to claim 1, characterized in that: Identifying all the turning regions on the cutting path according to the curvature change amounts includes the following steps: Divide the continuous cutting path into path segments of equal length, calculate the curvature change amount of each path segment, and the curvature change amount is obtained by measuring the angle difference between the tangent directions at both ends of the path segment; When the curvature change amounts of three consecutive path segments all exceed the reference curvature change amount, determine that this region is a turning region; Extend from the turning region to both sides until a path segment with a curvature change amount lower than the reference curvature change amount for the first time is found, and mark the endpoints of this path segment as the starting point or ending point of the turning region; After determining that the two endpoints of the turning region are the starting point and the ending point respectively, determine the midpoint of the path between the starting point and the ending point as the center point.

3. The process control method for laser cutting of an optical element according to claim 2, characterized in that: The reference curvature change amount is determined through the following steps: Conduct a standard straight-line cutting test on the target optical element material, and record the natural curvature fluctuation range during the cutting process; Based on the results of the standard straight-line cutting test, select the maximum allowable curvature change amount when the cutting quality meets the standard as the initial reference value; During the actual cutting process, dynamically correct the initial reference value according to the real-time monitored cutting quality feedback, and the correction amplitude does not exceed ±20% of the initial reference value; For cutting regions with different thicknesses, adjust the reference curvature change amount according to the thickness ratio. For every 0.1 mm increase in thickness, the reference value is correspondingly increased by 5%.

4. The process control method for laser cutting of an optical element according to claim 2, characterized in that: Taking the starting point of the cutting path as the coordinate origin, establish a plane rectangular coordinate system, represent the starting point, center point and ending point in the coordinate system with coordinates, and call the coordinates of each feature point in real time during the cutting process to guide the adjustment of process parameters.

5. The process control method for laser cutting of an optical element according to claim 1, characterized in that: Identifying the offset amount and offset direction of the heat center point relative to the laser spot center according to the lateral temperature distribution includes the following steps: Taking the theoretical center of the laser spot as the reference point, divide the detection area into four quadrants, use an infrared thermal imager to sequentially scan the temperature distribution of each quadrant, and record the highest temperature value and the corresponding coordinate position in each quadrant; Compare the highest temperature values in the four quadrants to determine the dominant quadrant where the temperature distribution is most concentrated. In this dominant quadrant, select the area with the largest temperature gradient change as the high-temperature core area, and calculate the geometric center of all high-temperature points in the high-temperature core area as the actual heat center point; Connect the theoretical center of the laser spot and the actual heat center point to form a reference line, measure the length of the reference line as the offset, and use the cutting forward direction as the reference axis to measure the angle between the reference line and the reference axis as the offset direction.

6. The process control method for laser cutting of optical elements according to claim 1, characterized in that: Dynamically adjusting the laser power according to the offset includes the following steps: Divide the detected offset into several levels, and each level corresponds to a different power adjustment amplitude; Determine the basic power value according to the path characteristics of the current cutting position, and the basic power value is the minimum power value that meets the quality standard during straight-line cutting; When the offset is within the first-level range, keep the current power unchanged; When the offset is within the second-level range, gradually reduce the power according to the first adjustment amplitude, and the first adjustment amplitude is 3% - 5% of the current power value; When the offset is within the third-level range, quickly reduce the power according to the second adjustment amplitude, and the second adjustment amplitude is 6% - 8% of the current power value; Power lower limit protection: Set the minimum power threshold to ensure the continuous and stable progress of the cutting process.

7. The process control method for laser cutting of an optical element according to claim 1, characterized in that: Dynamically adjusting the cutting speed according to the offset includes the following steps: Determine the speed adjustable range according to the material type and thickness; Establish an offset-speed mapping relationship, including: the small-offset interval corresponds to a 5% - 10% reduction in speed; the medium-offset interval corresponds to an 11% - 20% reduction in speed; the large-offset interval corresponds to a 21% - 30% reduction in speed; Set the upper limit of the speed change rate to 5% per second, and use a progressive transition when switching between adjacent offset intervals; Real-time monitor the change in the quality of the cutting surface, and dynamically optimize the offset-speed mapping relationship according to the cutting effect.

8. The process control method for laser cutting of an optical element according to claim 1, characterized in that: While adjusting the position of the laser spot according to the offset direction, introduce auxiliary gas to adjust the heat offset. According to the offset compensation direction of the laser spot, synchronously adjust the spraying angle of the auxiliary gas nozzle to align the center line of the gas flow field with the midpoint line position of the compensated laser spot.

9. The process control method for laser cutting of optical elements according to claim 1, characterized in that: Also includes: Real-time monitor the amplitude and frequency of energy fluctuations during the cutting process. When the amplitude of energy fluctuations exceeds 30% of the normal range and lasts for more than 50 ms, it is determined as an abnormal situation; Immediately freeze the current laser power and cutting speed parameters, and keep the position of the laser spot unchanged in the current compensation state; Analyze the change trend of the temperature distribution in the last 10 sampling periods, detect whether there is a sudden change in the movement trajectory of the heat center point, and check whether the optical path system is interfered; If it is diagnosed as an instantaneous interference, continue cutting with the current parameters. If it is diagnosed as a continuous abnormality, start a progressive parameter rollback mechanism; Gradually restore the laser power by 50% of the original adjustment amount, synchronously adjust the cutting speed according to the power restoration ratio, and finally restore the spot position to ensure the stability of the thermal field. After completion, re-establish the normal adjustment mechanism.

10. An optical element laser cutting process control system, characterized in that, Includes: A path analysis module, which is used to obtain all the curvature change amounts in the laser cutting path, identify all the turning regions on the cutting path according to the curvature change amounts, and determine the starting point, center point and ending point of each turning region; A thermal field monitoring module, which is used to obtain the lateral temperature distribution of the laser action region in real time during the cutting process, and when the cutting reaches the starting point, identify the offset amount and offset direction of the heat center point relative to the laser spot center; A control and adjustment module, connected to the thermal field monitoring module, is used for: Dynamically adjusting the laser power and cutting speed according to the offset amount, so that the laser power gradually decreases as the offset amount increases, and the cutting speed gradually decreases as the offset amount increases; Adjusting the laser spot position according to the offset direction and offset amount to compensate for the offset of the heat center; A parameter restoration module, which is used to, when the cutting reaches the center point, equally amplitude and reversely adjust the laser power, cutting speed and laser spot position according to the dynamic change amounts of the laser power, cutting speed and laser spot position between the starting point and the center point, so that when the cutting reaches the ending point, the laser power, cutting speed and laser spot position all return to the initial parameters; An execution module, which is used to execute the instructions of the control and adjustment module and the parameter restoration module to complete the laser cutting operation.

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