Laser cutting control system for superhard material clad sheet

Abstract

The invention relates to the technical field of laser cutting, in particular to a laser cutting control system for a superhard material clad sheet, which comprises a monitoring module used for acquiring an initial scanning path of a laser beam for the superhard material clad sheet, dividing a plurality of nodes in the initial scanning path, dividing adjacent nodes into a scanning section, the monitoring module respectively records the cutting speed of each scanning section and the cutting degree parameter of each node in the scanning process; the path control unit generates a supplementary scanning path based on the cutting degree parameter of each node; the speed control unit determines the scanning speed of each scanning section in the supplementary scanning path based on the cutting degree parameters of the nodes at the two ends of the scanning section, and the cutting degree of each node can be effectively quantified and represented through parallel configuration collection of the photoelectric detector array. Therefore, the optimization of the path and the speed determined based on the cutting degree of each node is better matched with the actual working condition, and the forming precision of the superhard material clad sheet in the laser cutting process is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of laser cutting, and particularly to a laser cutting control system for superhard material composite sheets. Background Art

[0002] "Superhard material composite sheets" generally refer to composite materials formed by sintering superhard materials and cemented carbide substrates at high temperature and high pressure. Superhard materials mainly refer to diamond and cubic boron nitride. Due to their excellent properties such as high hardness and high wear resistance, superhard material composite sheets have important application values in fields such as oil drilling and precision machining. However, their superhard properties also make traditional machining extremely difficult, and laser cutting technology has become the main machining method due to its non-contact and high-precision characteristics.

[0003] For example, in the prior art, Chinese Patent Publication No. CN108453373A discloses a laser cutting machine control system, including: a machine tool bed body, including a top cover and a body, with first through holes evenly arranged on the top cover, and a drawer arranged inside the body; a cutting machine main body arranged on the left side of the top cover; a machine tool guide rail arranged on the right side of the top cover, with second through holes evenly arranged on the machine tool guide rail; a robotic arm, one end of the robotic arm is connected to the cutting machine main body, and the other end of the robotic arm is provided with a laser cutting head of the laser cutting machine; a camera arranged at the front end of the laser head of the laser cutting head. Its technical solution improves the consistency of laser cutting, but requires continuous manual observation and parameter adjustment.

[0004] However, the following technical problems exist in the above technology: First, the thickness deviation of the composite layer inside the material is likely to cause deviation in laser cutting quality, resulting in inconsistent cutting depth or even local non-penetration; Second, traditional laser cutting systems mostly adopt fixed scanning paths and power parameters, and it is difficult to dynamically adjust process parameters according to the real-time cutting state; Third, existing monitoring means mostly rely on off-line detection or single-parameter feedback, and it is impossible to achieve on-line evaluation and closed-loop control of cutting quality. Summary of the Invention

[0005] Therefore, the present invention provides a laser cutting control system for superhard material composite sheets to solve at least one of the technical problems in the above background art.

[0006] To achieve the above object, the present invention provides a laser cutting control system for superhard material composite sheets, including a monitoring module and a control module.

[0007] Among them, the monitoring module is used to obtain the initial scanning path of the laser beam for the superhard material composite sheet, delimit a number of nodes in the initial scanning path, divide adjacent nodes into a scanning segment, and the monitoring module respectively records the cutting speed of each scanning segment and the cutting degree parameters of each node during the scanning process; the control module is connected to the monitoring module and includes a path control unit and a speed control unit; the path control unit responds to the abnormal cutting degree parameter of any node after the laser beam scans the initial scanning path, and generates a supplementary scanning path based on the cutting degree parameters of each node; the speed control unit is configured to re-divide the supplementary scanning path into scanning segments, and determine the scanning speed of each scanning segment in the supplementary scanning path based on the cutting degree parameters of the nodes at both ends of the scanning segment.

[0008] As a preferred technical solution of the laser cutting control system for the superhard material composite sheet, the monitoring module specifically includes an optoelectronic detector array arranged parallel to and spaced from the laser beam, and the optoelectronic detector array receives the light generated by the laser beam after passing through the superhard material composite sheet in the direction parallel to the laser beam.

[0009] As a preferred technical solution of the laser cutting control system for the superhard material composite sheet, the monitoring module is configured to execute the following process to determine the cutting degree parameter: Obtain the average current of the optoelectronic detector array during the period corresponding to the cutting of the node, and determine the cutting degree parameter based on the average current of the optoelectronic detector array; Among them, the cutting degree parameter is positively correlated with the average current of the optoelectronic detector array.

[0010] As a preferred technical solution of the laser cutting control system for the superhard material composite sheet, the monitoring module specifically executes the following operation to determine the cutting degree parameter: Cutting degree parameter K = I1 / I2, where I1 is the average current of the optoelectronic detector array during the period corresponding to the cutting of the node, and I2 is the average current of the optoelectronic detector array when receiving the light of the original laser beam that has not passed through the superhard material composite sheet in the direction parallel to the laser beam.

[0011] As a preferred technical solution of the laser cutting control system for the superhard material composite sheet, the determination of the abnormal cutting degree parameter by the path control unit includes comparing the cutting degree parameter with the corresponding threshold. If it is less than the corresponding threshold, it is determined that the cutting degree parameter is abnormal.

[0012] As a preferred technical solution of the laser cutting control system for the superhard material composite sheet, the path control unit sets different thresholds for nodes with different passing times of the laser beam in the initial scanning path, and the greater the passing times of the laser beam at the node in the initial scanning path, the greater the threshold corresponding to the node.

[0013] As a preferred technical solution of the laser cutting control system for superhard material composite sheets, the path control unit responds to the abnormal cutting degree parameter of only one node, and takes the shortest path passing through the initial node and the node with abnormal cutting degree parameter as the supplementary scanning path.

[0014] As a preferred technical solution of the laser cutting control system for superhard material composite sheets, the path control unit responds to the abnormal cutting degree parameters of more than one node, and takes the shortest path passing through each node with abnormal cutting degree parameter as the supplementary scanning path.

[0015] As a preferred technical solution of the laser cutting control system for superhard material composite sheets, the speed control unit is further configured to: dynamically adjust the scanning speed of the scanning segment according to the difference between the cutting degree parameters of the two end nodes of the scanning segment; Wherein, when the difference between the cutting degree parameters exceeds a preset threshold, the scanning speed is reduced and the number of repeated scans of the laser beam of this scanning segment is increased in the supplementary scanning path.

[0016] As a preferred technical solution of the laser cutting control system for superhard material composite sheets, the monitoring module defines the constraint conditions of each node as: The path lengths of each scanning segment are the same, Or, the node is a path inflection point.

[0017] Compared with the prior art, the beneficial effect of the present invention is that through the parallel configuration acquisition of the photodetector array, the cutting degree of each node can be effectively quantified and characterized, so that the optimization of the path and speed determined based on the cutting degree of each node is more matched to the actual working conditions, thereby effectively improving the forming accuracy of the superhard material composite sheet during the laser cutting process.

[0018] Furthermore, the present invention sets up a monitoring module based on the photodetector array, and quantifies and analyzes the light signal intensity after the laser penetrates the material as the cutting degree parameter, breaking through the lag defect of traditional off-line detection, and realizing the on-line dynamic evaluation of the cutting depth. Combining the node division and the scanning segment segmentation recording mechanism, the complex cutting path is discretized into units that can be independently analyzed, accurately locating the abnormal area, and providing high-resolution data support for subsequent parameter adjustment.

[0019] Furthermore, the path control unit of the present invention intelligently generates a supplementary scanning path according to the spatial distribution characteristics of the abnormal nodes, avoiding the energy redundancy caused by traditional fixed repeated scanning. By dynamically associating the number and position of abnormal nodes with the supplementary path planning, while ensuring the cutting integrity, the ineffective scanning stroke is reduced, comprehensively improving the processing efficiency and reducing the energy consumption.

[0020] Furthermore, the speed control unit of the present invention dynamically adjusts the scanning speed and the repeated scanning frequency based on the gradient difference of the cutting degree parameters of adjacent nodes: for the regions with sudden changes in cutting degree, accurate energy compensation is achieved by reducing the speed and superimposing multiple scans. This mechanism effectively suppresses the cutting depth fluctuations caused by local material property differences and avoids the defects of overburning or insufficient penetration caused by adjusting a single parameter.

[0021] Furthermore, the photodetector array of the present invention can be adapted to lasers of different wavelengths, and the path planning algorithm supports multiple cutting trajectory modes. The architecture design of the present invention facilitates system upgrade and transformation, meets the processing requirements of superhard material composite sheets of multiple specifications, and has wide industrial applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a structural block diagram of the laser cutting control system for superhard material composite sheets according to an embodiment of the present invention; Figure 2 is a schematic diagram of a superhard material composite sheet and an initial scanning path according to an embodiment of the present invention.

[0023] In the figure, 1, superhard material composite sheet; 2, initial node of the scanning path; 3, end node of the scanning path; 4, superhard material cutting head. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] In order to make the objectives and advantages of the present invention more clear, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0026] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0027] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Please refer to Figure 1 and Figure 2 As shown, they are respectively the structural block diagram of the laser cutting control system for superhard material composite sheets in the embodiments of the present invention and the schematic diagram of the superhard material composite sheets and the initial scanning path in the embodiments of the present invention. The initial scanning path of the laser cutting device starts from the initial scanning path node 2 on the superhard material composite sheet 1 and ends at the scanning path end node 3. During the process, several superhard material cutting heads 4 with the same shape are cut from the superhard material composite sheet 1. In the above laser cutting process, the laser cutting control system for superhard material composite sheets of the present invention is used to control the laser cutting device. The laser cutting control system for superhard material composite sheets further includes a monitoring module and a control module.

[0029] Among them, the monitoring module is used to obtain the initial scanning path of the laser beam for the superhard material composite sheet, and demarcate several nodes in the initial scanning path (the constraint conditions for demarcating each node in this embodiment are: the path lengths of each scanning segment are the same. In practice, the path inflection points can also be divided into nodes. The same path length can ensure uniformity, and path inflection points are more likely to have cutting problems. Targeted detection can improve the representation ability of the cutting degree parameters for the overall cutting process. In practice, the selection between the two node division methods can be made according to the actual working conditions). Adjacent nodes are divided into a scanning segment, and the monitoring module respectively records the cutting speed of each scanning segment and the cutting degree parameters of each node during the scanning process; the control module is connected to the monitoring module and includes a path control unit and a speed control unit; the path control unit responds to the abnormal cutting degree parameter of any node after the laser beam scans the initial scanning path, and generates a supplementary scanning path based on the cutting degree parameters of each node; the speed control unit is configured to re-divide the supplementary scanning path into scanning segments, and determine the scanning speed of each scanning segment in the supplementary scanning path based on the cutting degree parameters of the two end nodes of the scanning segment.

[0030] Specifically, the core architecture of the laser cutting control system for superhard material composite sheets is jointly constituted by a monitoring module and a control module. The monitoring module integrates a high-precision optoelectronic sensor array and a path planning algorithm. Its hardware part includes a linear array CCD detector group arranged parallel to the side of the laser cutting head, ensuring that the scattered laser signal after penetrating the superhard material composite sheet can be captured in real time. In the initialization stage, the monitoring module generates an initial scanning path based on a preset cutting profile. This path is divided into several equally spaced nodes through discretization processing, and independent scanning segments are formed between adjacent nodes. During the scanning process, the monitoring module synchronously records the actual cutting speed of each scanning segment, and dynamically calculates the cutting degree parameters of each node by analyzing the change rate of the current signal of the optoelectronic detector array in the corresponding time period, forming a three-dimensional data matrix containing the spatial position-cutting quality mapping relationship.

[0031] Specifically, the monitoring module specifically includes an optoelectronic detector array arranged parallel to and spaced from the laser beam. The optoelectronic detector array receives the light generated by the laser beam passing through the superhard material composite sheet in the direction parallel to the laser beam. The monitoring module is configured to execute the following process to determine the cutting degree parameters: obtain the average current of the optoelectronic detector array during the time period corresponding to the cutting of the node (i.e., the average value of the current values of each optoelectronic detector), and determine the cutting degree parameters based on the average current of the optoelectronic detector array; Among them, the cutting degree parameter is positively correlated with the average current of the photodetector array. Specifically, for the quantitative evaluation of the cutting degree parameter, the monitoring module is built with a dedicated signal processing chip to execute the following standardization processing flow: First, when the laser beam scans to the corresponding area of each node, the time window synchronization mechanism is triggered to collect the average current value (I1) of all activated detection units during this period, and dynamically compare it with the pre-stored reference current value (I2, calibrated by the average current collected by the photodetector array when the laser does not perform cutting). The calculation of the cutting degree parameter K is realized through the formula K = I1 / I2, and its physical meaning represents the light beam blocking effect of the material penetration degree on the laser. Since the cutting depth of the superhard material composite sheet is positively correlated with the laser transmittance, when the cutting depth is relatively high, more laser energy reaches the photodetector array, resulting in an increase in I1 and an increase in the K value. Therefore, the system establishes an inverse mapping relationship between the K value and the cutting quality: the closer the K value is to 1 (i.e., I1 approaches I2), it indicates that the node area is effectively cut; the lower the K value, it reflects ineffective cutting. Further, the control module is connected to the monitoring module through a high-speed data bus, and the path control unit and the speed control unit integrated inside it form a closed-loop control chain. After the initial scan is completed, the path control unit retrieves the K value data of all nodes and uses the threshold comparison algorithm to detect abnormalities point by point: for the nodes with K values lower than the corresponding thresholds, it is determined that the cutting degree parameter is abnormal. Subsequently, the path control unit generates a supplementary scan path based on the spatial distribution characteristics of the abnormal nodes. It should be understood that the supplementary scan path is included in the initial scan path and no new cutting positions should appear, but only a repetition of some cutting paths. In this embodiment, the superhard material composite sheet is a diamond composite sheet, and the corresponding relationship between the node and the threshold is that when the number of passes of the laser beam at the node is one, the corresponding threshold is 0.85; when the number of passes of the laser beam at the node is two, the corresponding threshold is 0.89; when the number of passes of the laser beam at the node is three, the corresponding threshold is 0.95. In this embodiment, there is no situation where the number of passes of the laser beam at the node is greater than three. In practice, the threshold can be set to other values in combination with the specific material and cutting requirements of the superhard material composite sheet.

[0032] Specifically, when there is a single abnormal node, a shortest straight-line path connecting the starting point of the initial path and this node is generated; if there are multiple abnormal nodes, the optimal broken-line path covering all abnormal nodes is calculated through the traversal algorithm to minimize the idle travel to the greatest extent. After receiving the supplementary scan path data, the speed control unit first adaptively segments the path: according to the distance between adjacent abnormal nodes and the K value gradient difference, the supplementary path is divided into several variable-length scan segments.

[0033] Specifically, the speed control unit is further configured to: dynamically adjust the scan speed of this scan segment according to the difference in the cutting degree parameters of the nodes at both ends of the scan segment; Among them, when the difference of the cutting degree parameter exceeds the preset threshold, the scanning speed is reduced and the number of repeated scans of the laser beam in this scan segment is increased in the supplementary scan path. The determination of the path control unit for abnormal cutting degree parameters includes comparing the cutting degree parameter with the corresponding threshold. If it is less than the corresponding threshold, it is determined that the cutting degree parameter is abnormal. Moreover, the path control unit sets different thresholds for nodes with different passing times of the laser beam in the initial scan path, and the greater the passing times of the laser beam at the node in the initial scan path, the greater the corresponding threshold of the node. For each scan segment, the speed control unit calculates the difference in the K value between its starting point and ending point. If the difference exceeds the preset gradient threshold (0.2 in this embodiment), it is determined that there is a risk of sudden change in material properties in this segment, and the scanning speed is automatically reduced to 50%-70% of the reference value, and the repeated scanning mechanism is triggered (the number of repetitions is proportional to the difference in the K value); otherwise, the reference scanning speed is maintained. This dynamic speed regulation strategy avoids local overheating while ensuring the precise deposition of energy in the weak areas of the material.

[0034] To eliminate the interference of environmental noise, the monitoring module further introduces a moving average filtering algorithm in the data processing stage: the current signal corresponding to each node is segmented in the time domain, and abnormal peaks caused by material splashing or instantaneous saturation of the detector are removed. Finally, the weighted average of the filtered data of each segment is taken as the effective I1 value. In addition, the system automatically records the reference current I2 when there is no material occlusion during the initialization stage, and performs online calibration regularly according to the laser power drift situation to ensure the long-term stability of the K value calculation. This design makes the detection accuracy of the cutting degree parameter unaffected by laser aging or environmental light fluctuations, and significantly improves the reliability of quality assessment.

[0035] Through the synergistic effect of the above hardware layout and algorithm design, the monitoring module realizes two core functions: First, in the spatial dimension, it accurately correlates the laser scanning position with the cutting quality data to form a process database containing the coordinates of each node, the real-time K value, and the historical change curve; Second, in the time dimension, through the millisecond-level signal acquisition rate, it captures the instantaneous quality fluctuations caused by material inhomogeneity during the cutting process, providing high-refresh-rate data support for the real-time decision-making of the control module.

[0036] Specifically, the path control unit responds to the abnormal cutting degree parameter of only one node, and uses the shortest path passing through the initial node and the node with the abnormal cutting degree parameter as the supplementary scanning path. In response to the abnormal cutting degree parameters of more than one node, the shortest path passing through each node with the abnormal cutting degree parameter is used as the supplementary scanning path. In the above embodiment, when the path control unit executes the supplementary scanning path planning, a differential strategy is adopted to cope with the abnormal node distribution scenarios of different orders of magnitude. In this process, the path control unit calls the device kinematic model to verify the path feasibility in real time, combines the mechanical parameters such as the maximum acceleration and steering angle limit of the laser head, and automatically optimizes the theoretical straight path into a composite curve path with smooth transition to ensure the trajectory stability of the laser scanning head during high-speed movement.

[0037] Through the dual optimization of spatial distribution feature recognition and energy demand prediction, the hierarchical path generation mechanism has achieved the following technical breakthroughs: First, rapid directional compensation in the single-node abnormal scenario, avoiding efficiency losses caused by large-area repeated scanning; Second, cluster path optimization in the multi-node abnormal scenario, significantly reducing the idle travel time of the device.

[0038] The flowcharts or block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of devices, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and the combinations of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based device for performing the specified functions or operations, or can be implemented by a combination of dedicated hardware and computer instructions.

[0039] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0040] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention; for those skilled in the art, various modifications and variations can be made to the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A laser cutting control system for superhard material composite sheets, characterized in that, Including: A monitoring module, configured to obtain an initial scanning path of a laser beam for the superhard material composite sheet, delimit a plurality of nodes in the initial scanning path, divide adjacent nodes into a scanning segment, and the monitoring module respectively records the cutting speed of each scanning segment and the cutting degree parameters of each node during the scanning process; A control module, connected to the monitoring module, including a path control unit and a speed control unit; Wherein, the path control unit generates a supplementary scanning path based on the cutting degree parameters of each node in response to an abnormal cutting degree parameter of any node after the laser beam scans the initial scanning path; The speed control unit is configured to re-divide the supplementary scanning path into scanning segments, and determine the scanning speed of each scanning segment in the supplementary scanning path based on the cutting degree parameters of the nodes at both ends of the scanning segment.

2. The laser cutting control system for superhard material composite sheets according to claim 1, wherein The monitoring module specifically includes an array of photodetectors arranged parallel to and spaced from the laser beam, and the array of photodetectors receives the light generated by the laser beam passing through the superhard material composite sheet in a direction parallel to the laser beam.

3. The laser cutting control system for superhard material composite sheets according to claim 2, wherein The monitoring module is configured to execute the following process to determine the cutting degree parameter: Obtain the average current of the photodetector array during the period corresponding to the cutting of the node, and determine the cutting degree parameter based on the average current of the photodetector array; Wherein, the cutting degree parameter is positively correlated with the average current of the photodetector array.

4. The laser cutting control system for superhard material composite sheets according to claim 3, wherein, The monitoring module specifically executes the following operation to determine the cutting degree parameter: Cutting degree parameter K = I1 / I2, where I1 is the average current of the photodetector array during the period corresponding to the cutting of the node, and I2 is the average current of the photodetector array when receiving the light of the original laser beam that has not passed through the superhard material composite sheet in a direction parallel to the laser beam.

5. The laser cutting control system for superhard material composite sheets according to claim 1, wherein The determination of the path control unit for an abnormal cutting degree parameter includes comparing the cutting degree parameter with a corresponding threshold. If it is less than the corresponding threshold, it is determined that the cutting degree parameter is abnormal.

6. The laser cutting control system for superhard material composite sheets according to claim 5, characterized in that, The path control unit sets different thresholds for nodes with different passing times of the laser beam in the initial scanning path, and the greater the passing times of the laser beam at the node in the initial scanning path, the greater the corresponding threshold of the node.

7. The laser cutting control system for superhard material composite sheets according to claim 1, wherein The path control unit, in response to an abnormal cutting degree parameter of only one node, uses the shortest path passing through the initial node and the node with the abnormal cutting degree parameter as the supplementary scanning path.

8. The laser cutting control system for superhard material composite sheets according to claim 7, wherein, The path control unit, in response to an abnormal cutting degree parameter of more than one node, uses the shortest path passing through each node with the abnormal cutting degree parameter as the supplementary scanning path.

9. The laser cutting control system for superhard material composite sheets according to claim 1, characterized in that, The speed control unit is further configured to: dynamically adjust the scanning speed of the scanning segment according to the difference between the cutting degree parameters of the nodes at both ends of the scanning segment; Wherein, when the difference between the cutting degree parameters exceeds a preset threshold, the scanning speed is reduced and the number of repeated scans of the laser beam in this scanning segment is increased in the supplementary scanning path.

10. The laser cutting control system for superhard material composite sheets according to claim 1, characterized in that, The constraint conditions for the monitoring module to delimit each node are: The path lengths of each scanning segment are the same, Or, the node is a path inflection point.

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