A control method and system for laser cutting point position storage and trajectory automatic generation

Abstract

The application discloses a control method and system for laser cutting point position storage and track automatic generation, and relates to the technical field of laser cutting control. The method comprises the following steps: acquiring workpiece contour data, dividing a plurality of cutting partitions and allocating storage units; determining the cutting starting point and the cutting ending point of each partition, writing the coordinates into the corresponding storage units and recording the correspondence between the partition identification and the storage units; determining the initial cutting sequence and generating the initial cutting track according to the stored coordinates of each partition; determining the heat affected zone generated by the previous cutting partition in the cutting process, when the starting point or the ending point of the subsequent partition falls into the zone, comparing the cooling waiting time with the bypass stroke time, adjusting the cutting sequence or generating the bypass track; recording the current partition identification and the laser head position when the cutting is interrupted, determining the open endpoint when the cutting is resumed and generating the cutting-in path to the uncut area again. The application realizes the structured storage of the cutting partition, the online avoidance of the heat affected zone and the waste-free continuous cutting at the breakpoint.

Description

Technical Field

[0001] This application relates to the field of laser cutting control technology, and more specifically, to a control method and system for storing laser cutting points and automatically generating trajectories. Background Technology

[0002] In laser cutting, the demand for efficient cutting of complex workpiece contours necessitates that cutting equipment perform zoning, path planning, and thermal impact management of the workpiece contour. This specific scenario presents challenges such as long cutting trajectory idle times, workpiece deformation due to heat accumulation, and difficulty in resuming cutting without waste after interruption. Existing cutting control methods often generate trajectories using a fixed sequence or simple greedy sorting, making it difficult to achieve a balance between efficiency, thermal damage control, and breakpoint recovery. Furthermore, the lack of structured storage and process attribute-related management of the point data in each cutting zone results in insufficient flexibility in path adjustment.

[0003] Therefore, how to control the thermal impact while improving cutting efficiency and supporting waste-free re-cutting after cutting interruption is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0004] The purpose of this application is to provide a control method and system for storing laser cutting points and automatically generating trajectories. This system has the advantages of enabling structured storage of cutting zones, online avoidance of heat-affected zones, and continuous cutting without waste at breakpoints, thereby improving cutting efficiency, finished product quality, and process continuity.

[0005] This application provides a control method for storing laser cutting points and automatically generating trajectories, including: Obtain the contour data of the workpiece to be cut, divide the workpiece contour into multiple cutting partitions, and allocate a storage unit for each partition; Determine the starting and ending points of each cutting partition, write their coordinates into the corresponding storage unit, and record the correspondence between the partition identifier and the storage unit; Based on the coordinates of the cutting start and cutting end points stored in each partition, the initial cutting order of each cutting partition is determined, and the initial cutting trajectory is generated; Each cutting section is cut according to the initial cutting trajectory; during the cutting process, the heat-affected zone generated by the previously cut section is determined. When the starting point or ending point of the subsequent section to be cut falls into this zone, the cooling waiting time and the detour idle time are compared, and the initial cutting sequence is adjusted or a detour trajectory is generated. When cutting is interrupted, the identifier of the current cutting partition and the position of the laser head at the time of interruption are recorded; when resuming, the open endpoint of the contour boundary within the partition is determined based on the recorded position, and the cutting path is regenerated from the open endpoint to the uncut area. Based on the adjusted cutting sequence, the bypass trajectory, or the cutting path, the laser head is controlled to continue performing the cutting operation.

[0006] Furthermore, the process of dividing the workpiece contour into multiple cutting sections includes: Extract the endpoint coordinates of the line segments in the contour data, and determine the connection relationship between the line segments in the contour based on the coincidence relationship of the endpoint coordinates between adjacent line segments; Based on the connection relationship, calculate the directional difference between adjacent line segments, and mark the connection positions where the directional difference is greater than a preset threshold as corner points; The continuous line segments between adjacent corner points are divided into the same cutting partition.

[0007] Furthermore, determining the starting and ending points of each cutting partition includes: For the segment containing the corner point, obtain the extension direction of the line segment adjacent to the corner point; The endpoint of the line segment extending towards the inside of the cutting partition is defined as the cutting start point, and the endpoint of the line segment extending towards the outside of the cutting partition is defined as the cutting end point.

[0008] Furthermore, determining the initial cutting order of each cutting partition includes: Use the position where the laser head stops after completing the current cutting section as the current reference position; Calculate the straight-line distance between the current reference position and the cutting start point and cutting end point of the next partition to be cut; The starting point or ending point of the cutting corresponding to the smallest straight-line distance shall be used as the starting point of the next partition to be cut. The position of the starting cutting point is updated to the current reference position, and the starting cutting point of the next partition to be cut is determined based on the updated current reference position, until all partitions are included in the initial cutting sequence.

[0009] Furthermore, determining the heat-affected zone generated by the previously cut partitions includes: Calculate the heat input time required to cut the previously cut partition based on the outline length and cutting speed of the previously cut partition; Based on the heat input duration and the heat dissipation characteristics of the workpiece, the heat diffusion range is determined; taking the outline of the previously cut partition as the center line, the heat diffusion range is extended to both sides of the outline, and the covered strip area is determined as the heat-affected zone.

[0010] Furthermore, the step of comparing the cooling waiting time with the detour idle time, and adjusting the initial cutting sequence or generating a detour trajectory, includes: Based on the heat dissipation characteristics of the material of the workpiece to be cut, estimate the cooling waiting time required for the heat-affected zone to cool to the preset temperature. Calculate the detour time to reach the cutting start or end point of the subsequent section to be cut by bypassing the heat-affected zone; When the cooling waiting time is less than the detour idle time, the initial cutting sequence is adjusted so that the subsequent partitions to be cut are cut after waiting for the cooling waiting time. When the detour idle time is less than or equal to the cooling waiting time, a detour trajectory is generated to bypass the heat-affected area and reach the subsequent partition to be cut.

[0011] Furthermore, it also includes: when cutting is interrupted, recording the temperature of the heat-affected zone at the moment of interruption; when cutting is resumed, if the temperature of the heat-affected zone is higher than the preset temperature, cutting the cutting sections that do not fall into the heat-affected zone is cut first, and cutting the cutting sections that fall into the heat-affected zone is cut only after the temperature of the heat-affected zone is no higher than the preset temperature.

[0012] Furthermore, the process of determining the open endpoints of the contour boundary within the partition based on the recorded location during recovery includes: Based on the position of the laser head at the moment of interruption, as well as the positions of the cutting start and cutting end points of the partition, determine the number of parts that have been cut in the cutting start and cutting end points of the partition; When the quantity is one, the cutting start point or cutting end point that has not yet been cut is determined as the open endpoint; When the number is zero or two, the contour boundary of the partition is determined to be closed, and no new entry path is generated for the partition.

[0013] Furthermore, the regeneration of the entry path includes: Obtain the tangent direction of the contour boundary at the open endpoint; The side of the tangent direction that is away from the already cut contour within the partition is defined as the uncut area; A guide segment is generated from the open endpoint along the tangential direction toward the uncut region, and the guide segment is connected to the unexecuted portion of the initial cutting trajectory or the detour trajectory to obtain the cutting path.

[0014] Furthermore, this application also proposes a control system for storing laser cutting points and automatically generating trajectories, including: The acquisition and storage module acquires the contour data of the workpiece to be cut, divides the workpiece contour into multiple cutting sections, allocates a storage unit to each section, determines the cutting start point and cutting end point of each cutting section, writes its coordinates into the corresponding storage unit, and records the correspondence between the section identifier and the storage unit. The trajectory generation module determines the initial cutting order of each cutting partition and generates the initial cutting trajectory based on the coordinates of the cutting start and cutting end points stored in each partition. The adjustment module cuts each cutting partition according to the initial cutting trajectory. During the cutting process, it determines the heat-affected zone generated by the previously cut partition. When the starting point or ending point of the subsequent partition to be cut falls into this zone, it compares the cooling waiting time with the detour idle time and adjusts the initial cutting order or generates a detour trajectory. When the cutting is interrupted, it records the identifier of the current cutting partition and the position of the laser head at the time of interruption. When resuming, it determines the open endpoint of the contour boundary within the partition based on the recorded position and regenerates the cutting path from the open endpoint to the uncut area. The control module controls the laser head to continue performing the cutting operation according to the adjusted cutting sequence, the detour trajectory, or the cutting path.

[0015] Compared to existing technologies, this application achieves structured association storage of cutting points and partition identifiers by dividing the workpiece contour into multiple cutting zones and allocating storage units to each zone for point data management. This overcomes the shortcomings of existing technologies, such as linear storage of point data leading to loss of partition attributes and difficulty in dynamically adjusting paths according to process requirements. Furthermore, by determining the heat-affected zone in real time based on the contour length and cutting speed of the preceding zone during sequential cutting, and dynamically adjusting the cutting sequence or generating detour trajectories by comparing cooling waiting time and detour idle time, this application overcomes the shortcomings of existing technologies where heat avoidance and idle optimization are independent and difficult to balance efficiency and thermal damage control. Finally, by recording the partition identifier and laser head position when cutting is interrupted, and regenerating the cutting path to the uncut area based on the open endpoints of the already cut contour during resumption, this application overcomes the shortcomings of existing technologies where re-cutting of already cut areas or direct cutting from the scrap area can easily damage the finished product. Therefore, this application improves cutting efficiency while reducing the risk of thermal deformation and achieves waste-free re-cutting after cutting interruption, significantly improving finished product quality and process continuity. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart illustrating the steps of the control method for storing laser cutting points and automatically generating trajectories disclosed in the embodiments of this application; Figure 2This is a flowchart illustrating the process of determining the initial cutting order of each cutting partition as disclosed in an embodiment of this application; Figure 3 This is a schematic diagram of the process disclosed in the embodiments of this application for comparing cooling waiting time with detour idle time, adjusting cutting order or generating detour trajectory; Figure 4 This is a schematic diagram of the control system structure for storing laser cutting points and automatically generating trajectories disclosed in the embodiments of this application. Detailed Implementation

[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which these embodiments belong; the terminology used herein and in the specification of the application is for the purpose of describing particular embodiments only and is not intended to limit these embodiments; the terms "comprising" and "having," and any variations thereof, in the specification of these embodiments and the foregoing drawings, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification of these embodiments and the foregoing drawings are used to distinguish different objects, not to describe a particular order.

[0019] The implementation details of the technical solution in this embodiment are described in detail below: This application proposes a control method for storing laser cutting points and automatically generating trajectories, such as... Figure 1 As shown, the method includes: S101, Obtain the contour data of the workpiece to be cut, divide the workpiece contour into multiple cutting partitions, and allocate a storage unit for each partition; Specifically, the contour data, which describes the outer and inner contours of the workpiece to be cut, is typically generated by upper-level typesetting software. The contour data consists of several line segments, each represented by the coordinates of its two endpoints in the workpiece coordinate system. The workpiece contour is divided into multiple cutting zones. The controller, based on the contour's geometry, breaks down the complete contour into several interconnected segments, each of which serves as a cutting zone. Each cutting zone contains at least one continuous line segment. A storage unit is allocated to each zone; that is, an independent storage area is designated in the controller's memory for each cutting zone. This storage area stores the starting and ending coordinates of the cutting zone. The correspondence between zone identifiers and storage units can be recorded using a lookup table. Each row in the lookup table stores a zone identifier and the address of the corresponding storage unit. The controller can locate the storage unit corresponding to the zone by querying the lookup table based on the zone identifier.

[0020] Furthermore, dividing the workpiece contour into multiple cutting zones includes: extracting the endpoint coordinates of line segments in the contour data; determining the connection relationship between line segments in the contour based on the coincidence relationship of endpoint coordinates between adjacent line segments; calculating the directional difference between adjacent line segments based on the connection relationship; marking connection positions with directional differences greater than a preset threshold as corner points; and assigning continuous line segments between adjacent corner points to the same cutting zone.

[0021] Specifically, the endpoint coordinates of line segments in the contour data are extracted. This involves traversing each line segment in the contour data and reading the x and y coordinates of the two endpoints of each line segment. The overlap of endpoint coordinates between adjacent line segments is determined: if the endpoint coordinates of the first line segment are the same as the starting coordinates of the second line segment, or if the difference between them is within a preset coordinate tolerance range, then these two line segments are considered connected. By traversing all line segments in this way, the connection relationships between line segments in the contour can be obtained, thus linking independent line segments into a complete contour chain.

[0022] This involves calculating the directional difference between adjacent line segments, specifically, calculating the directional angles of each of two connected line segments. The directional angle of a line segment is the angle between the direction vector from its starting point to its ending point and the positive direction of the horizontal axis of the workpiece coordinate system. Let the directional angles of two connected line segments be a1 and a2, and the directional difference dAng = |a2|. a1|;When dAng is greater than 180 degrees, change dAng to 360. |a2 a1| ensures that the directional difference falls between 0 and 180 degrees. A preset threshold is denoted as the corner threshold Aset. When dAng > Aset, it indicates a significant change in the contour at that connection point, and this connection point is marked as a corner. When dAng ≤ Aset, the connection point is considered a smooth transition and is not marked as a corner. The corner threshold Aset can be preset based on the contour characteristics and processing requirements of the workpiece. A smaller corner threshold is used for cases where contour changes are more sensitive, and a larger corner threshold is used for cases where contour changes are less sensitive.

[0023] In practical applications, continuous line segments between adjacent corner points are grouped into the same cutting partition. That is, on the resulting contour chain, the portion of the contour covered by all interconnected line segments between two adjacent corner points constitutes a cutting partition. Because the contour direction between corner points is smooth, the cutting conditions within a single cutting partition are essentially consistent, facilitating the unified determination of cutting direction and speed. When there are no corner points on the entire contour, the entire contour is treated as a single cutting partition.

[0024] S102, determine the cutting start point and cutting end point of each cutting partition, write their coordinates into the corresponding storage unit, and record the correspondence between the partition identifier and the storage unit.

[0025] Specifically, the cutting start point is the position where the laser head begins to cut a certain cutting zone, and the cutting end point is the position where the laser head finishes cutting that zone. The cutting start point and cutting end point of a cutting zone are located at opposite ends of that zone. The coordinates of the cutting start point and cutting end point are written into the corresponding storage units. That is, the storage unit corresponding to the zone is found by looking up the partition identifier in the lookup table, and the coordinates of the cutting start point and cutting end point are stored in that storage unit in sequence.

[0026] Furthermore, determining the cutting start point and cutting end point of each cutting partition includes: for the cutting partition containing the corner point, obtaining the extension direction of the line segment adjacent to the corner point; determining the endpoint of the line segment whose extension direction is towards the inside of the cutting partition as the cutting start point, and determining the endpoint of the line segment whose extension direction is towards the outside of the cutting partition as the cutting end point.

[0027] Specifically, the line segments adjacent to a corner point are defined as two line segments with that corner point as their endpoints. One line segment is located within the current cutting zone and extends inwards towards the interior of the current cutting zone, while the other line segment is located in an adjacent cutting zone and extends outwards towards the exterior of the current cutting zone. The endpoint of the line segment extending inwards towards the interior of the cutting zone, i.e., the endpoint of the line segment within the current cutting zone with the corner point as its endpoint, is determined as the cutting start point. The laser head enters the current cutting zone from this endpoint and begins cutting along the contour of the current zone. The endpoint of the line segment extending outwards towards the exterior of the cutting zone, i.e., the endpoint of the line segment located in an adjacent zone and extending outwards towards the exterior of the current cutting zone, is determined as the cutting end point. After the laser head cuts along the contour of the current zone to this endpoint, the cutting of the current cutting zone is completed, and the laser head moves to an adjacent cutting zone. When a cutting zone does not contain a corner point, for example, if the entire contour has no corner points and is considered as a single cutting zone, the cutting start point and cutting end point are directly taken as the two endpoints of the contour of that zone.

[0028] S103, Based on the coordinates of the cutting start point and cutting end point stored in each partition, determine the initial cutting order of each cutting partition and generate the initial cutting trajectory; Specifically, the initial cutting sequence is determined, which means arranging the execution order of each cutting section without considering the heat effect of cutting, so as to minimize the idle travel of the laser head between sections. The initial cutting trajectory is generated, which means connecting the contours of each section and the idle travel paths between the sections according to the initial cutting sequence to form the motion trajectory of the laser head.

[0029] Furthermore, the determination of the initial cutting order for each cutting partition is as follows: Figure 2 As shown, it includes steps S2001 to S2004.

[0030] S2001, the position where the laser head stops after completing the current cutting section is used as the current reference position; Specifically, the current cutting partition, which is the latest partition to be cut in the initial cutting sequence, is the location where the laser head stops after cutting this partition. This location is the current reference position. When starting the sorting, if there are no completed cutting partitions yet, the current reference position is taken as the initial tool setting position of the laser head or the cutting start point of the first cutting partition.

[0031] S2002, Calculate the straight-line distance between the current reference position and the cutting start point and cutting end point of the next partition to be cut; Specifically, let the coordinates of the current reference position be x1 and y1, and the coordinates of the starting point or ending point of the next partition to be cut be x2 and y2, then the straight-line distance is:

[0032] For each unsorted cutting partition, calculate the two straight-line distances from its cutting start point and cutting end point to the current reference position, and take the endpoint corresponding to the smaller straight-line distance as the candidate starting cutting point of the partition.

[0033] S2003, take the cutting start point or cutting end point corresponding to the smallest straight distance as the starting cutting point of the next partition to be cut; Specifically, the straight-line distances from all candidate starting cut points of unsorted partitions to the current reference position are compared, and the candidate starting cut point with the smallest distance is selected. The partition to which this candidate starting cut point belongs becomes the next partition to be cut, and the candidate starting cut point becomes the starting cut point of the next partition to be cut. When the starting cut point is the cutting endpoint of the partition, the partition moves in the reverse direction along the contour, cutting from the cutting endpoint to the cutting starting point.

[0034] S2004, update the position of the starting cutting point to the current reference position, and continue to determine the starting cutting point of the next partition to be cut based on the updated current reference position, until all partitions are included in the initial cutting sequence.

[0035] The above sorting process can be repeated in the following manner until all cut partitions are included in the initial cutting order: (1) For each unsorted cutting partition, calculate the straight-line distance from the current reference position to the cutting start point and cutting end point of the partition, and record the endpoint with the smaller straight-line distance in each partition as the candidate starting cutting point of the partition; (2) Among all candidate starting cut points, select the candidate starting cut point that is closest to the current reference position and place its partition at the end of the initial cut order; (3) Update the current reference position to the position of the candidate starting cut point and remove the partition from the unsorted cut partitions.

[0036] In the resulting initial cutting sequence, the laser head travel distance between two adjacent cutting zones is approximately the shortest, thus reducing the total cutting time.

[0037] S104, cut each cutting partition according to the initial cutting trajectory; during the cutting process, determine the heat-affected zone generated by the previously cut partition, and when the starting point or ending point of the subsequent partition to be cut falls into the zone, compare the cooling waiting time with the detour idle time, and adjust the initial cutting sequence or generate a detour trajectory.

[0038] Specifically, the previously cut sections are those sections that have already been cut before the current moment. During laser cutting, laser energy concentrates near the area being cut, causing the material temperature near the contour to rise and forming a heat-affected zone (HAZ). If the laser head immediately starts cutting within this HAZ before the temperature has cooled down, it can easily cause overheating at the starting point and a decrease in cut quality. Therefore, during the cutting process, the controller continuously determines the HAZ generated by the previously cut sections and checks whether the starting or ending point of the subsequent section to be cut falls into this area. Determining whether the starting or ending point falls into the HAZ involves comparing the coordinates of the starting or ending point with the HAZ. If the shortest distance from the point to the contour of a previously cut section is less than the heat diffusion range corresponding to that previously cut section, it is determined that the point falls into the HAZ of that previously cut section.

[0039] Furthermore, determining the heat-affected zone generated by the previously cut partition includes: calculating the heat input time required to cut the previously cut partition based on the contour length and cutting speed of the previously cut partition; determining the heat diffusion range based on the heat input time and the heat dissipation characteristics of the workpiece; and extending the heat diffusion range to both sides of the contour of the previously cut partition as the center line, and determining the covered strip area as the heat-affected zone.

[0040] Specifically, the heat input duration t = L / v, where L is the contour length of the previously cut section, i.e., the sum of the lengths of all line segments in that section, and v is the cutting speed, i.e., the feed rate of the laser head along the contour. The heat dissipation characteristics of the workpiece material are characterized by the thermal diffusivity h. Let the thermal conductivity of the material be k, the material density be ρ, and the specific heat capacity be c, then h = k / (ρ × c). The heat diffusion distance within the workpiece is proportional to the square root of the heat input duration; therefore, the heat diffusion range... Where C is a safety factor greater than 1, used to compensate for the influence of heat dissipation boundary conditions. After the heat diffusion range is determined, the heat-affected zone is a strip-shaped area covered by R extending to both sides of the previously cut contour as the center line.

[0041] Furthermore, by comparing the cooling waiting time with the detour idle time, the initial cutting sequence is adjusted or a detour trajectory is generated, such as... Figure 3 As shown, it includes steps S3001 to S3003.

[0042] S3001, Based on the heat dissipation characteristics of the material of the workpiece to be cut, estimate the cooling waiting time required for the heat-affected zone to cool to a preset temperature; Specifically, the temperature of the heat-affected zone decays exponentially with time. Let the peak temperature of the heat-affected zone at the moment the cutting is completed be Tq, the ambient temperature be Tb, and the cooling time constant be τ. Then, after time t, the temperature of the heat-affected zone is T = Tb + (Tq) / τ. Tb) × e ( t / τ) Where e is the natural constant, and the exponent term e( The cooling time constant τ decreases as t increases, indicating that the temperature gradually drops back to ambient temperature. The cooling time constant τ is determined by the thermal diffusivity and thickness of the workpiece material, reflecting the rate at which the temperature in the heat-affected zone drops. For example, it can be estimated as τ = δ² / h, where δ is the workpiece thickness and δ² / h is the characteristic time for heat to diffuse along the thickness direction. The larger the thickness or the smaller the thermal diffusivity, the slower the temperature drops. The preset temperature Tp is the upper limit of the temperature at which the process allows for the start of cutting. Let T = Tp, then the cooling waiting time tw = τ × ln((Tq) Tb) / (Tp Tb), where ln is the natural logarithm. When the peak temperature Tq is not higher than the preset temperature Tp, the heat-affected zone has met the cutting conditions, and the cooling waiting time is zero. S3002, calculate the travel time around the heat-affected zone to reach the cutting start point or end point of the subsequent cutting section; Specifically, the detour path is a movement path that avoids the heat-affected zone (HAZ) in a strip-like shape. It involves the laser head moving from its current position along the outer edge of the HAZ to the starting or ending point of the subsequent cutting section. The detour path can be formed by combining a broken line obtained by offsetting the HAZ boundary outwards by a safety margin with the line connecting the laser head's current position and the target point. Let the length of the detour path be Sb, and the laser head's idle travel speed be u. Then, the detour idle time td = Sb / u, where the idle travel speed u is the speed of the laser head when it is not emitting light.

[0043] S3003, when the cooling waiting time is less than the detour idle time, the initial cutting sequence is adjusted so that the subsequent partition to be cut is cut after waiting for the cooling waiting time; when the detour idle time is less than or equal to the cooling waiting time, a detour trajectory is generated to detour around the heat-affected area to reach the subsequent partition to be cut.

[0044] Specifically, when the cooling waiting time tw is less than the bypass idle time td, it indicates that the time required for the heat-affected zone to cool is shorter. In this case, the initial cutting sequence is adjusted, and other cutting sections that have not fallen into the heat-affected zone are cut earlier, so that the laser head can complete the cutting of the subsequent section after the cooling waiting time tw. When the bypass idle time td is less than or equal to the cooling waiting time tw, it indicates that the time required to bypass the heat-affected zone is shorter or equivalent. In this case, a bypass trajectory is generated, and the laser head moves along the bypass trajectory from the outside of the heat-affected zone to the cutting start or end point of the subsequent section, avoiding the high-temperature area without interrupting the cutting process.

[0045] S105, when cutting is interrupted, record the identifier of the current cutting partition and the position of the laser head at the time of interruption; when resuming, determine the open endpoint of the contour boundary within the partition based on the recorded position, and regenerate the cutting path from the open endpoint to the uncut area; Specifically, a cutting interruption refers to a situation where the laser head stops moving and emitting light during the cutting process due to reasons such as abnormal power supply, insufficient protective gas pressure, laser malfunction alarm, or manual pause. The current cutting zone is the cutting zone that the controller is executing at the moment of interruption. The controller records the identifier of the current cutting zone and the position of the laser head at the moment of interruption. Specifically, the controller writes the zone identifier of the current cutting zone and the coordinates (xr and yr) of the laser head in the workpiece coordinate system at the moment of interruption into non-volatile memory. This, in conjunction with the storage units of each cutting zone, allows the cutting progress before the interruption to be restored based on the recorded information even if the controller is powered off and restarted. The cut contour is the contour portion already formed by the laser head within the zone. Open endpoints are the endpoints between the cutting start and end points that have not yet been cut. Since the contour boundary of the zone is only partially cut during the interruption, the uncut endpoints are the open endpoints of the zone's contour boundary. The uncut area is the uncut contour portion within the zone extending from the interruption position to the open endpoints.

[0046] Furthermore, the process of determining the open endpoint of the contour boundary within the partition based on the recorded position during recovery includes: determining the number of cut start points and cut end points of the partition that have been completed based on the position of the laser head at the time of interruption and the positions of the cutting start point and cutting end point of the partition; when the number is one, the cutting start point or cutting end point that has not yet been completed is determined as the open endpoint; when the number is zero or two, the contour boundary of the partition is determined to be in a closed state, and no new cutting path is generated for the partition.

[0047] Specifically, when determining the number of segments that have been cut, first establish the correspondence between the laser head position at the moment of interruption and the contour of the partition. Take the point on the contour of the partition that is closest to the laser head position at the moment of interruption as the projection point; specifically, for each line segment of the contour of the partition, draw a perpendicular line from the laser head position at the moment of interruption to the line containing the line segment. When the foot of the perpendicular falls on the line segment, record the distance from the laser head position at the moment of interruption to the foot of the perpendicular; otherwise, record the distance from the laser head position at the moment of interruption to the shorter of the two endpoints of the line segment. The foot of the perpendicular or the endpoint corresponding to the minimum value of the recorded distances for each line segment is the projection point. The arc length *sr* of the projection point is the sum of the lengths of all line segments preceding the line segment where the projection point is located, plus the length from the starting point of that line segment to the projection point. Let the cumulative arc length of the contour along the cutting direction from the starting cutting point be zero, the arc length of the other endpoint of the partition be the total contour length *Lt* of that partition, and the arc length of the projection point be *sr*. The number *n* of endpoints that have been cut is determined as follows: when the nearest distance from the laser head position to the contour of the partition is greater than the preset tolerance *dset* at the moment of interruption, it indicates that the laser head has not yet entered the partition to perform cutting, and the number *n* is zero; otherwise, the number *n* is the number of endpoints with an arc length not greater than *sr* between the starting and ending cutting points. The tolerance *dset* is set based on the servo positioning error when the laser head stops, used to distinguish whether the laser head stops near the contour of the partition or at an idle position far from the contour.

[0048] In practical applications, when the quantity n is one, the projection point is located between the two endpoints of the partition contour. The cut contour is the contour segment from the starting cutting point to the projection point. The contour between the projection point and the open endpoint is the uncut contour part. The open endpoint is the endpoint with an arc length greater than sr between the cutting start point and the cutting end point, which is the endpoint that has not yet been cut.

[0049] During recovery, the laser head cuts from the open endpoint along the uncut contour towards the projection point. The cut connects with the already cut contour at the projection point, completing the cutting of the partition. At this point, the tool path is opposite to the path before the interruption, essentially using the open endpoint as the starting point for reverse cutting. When the number n is zero, the partition contour has not yet been cut, and the contour boundary is intact. Recovery can proceed as before, starting from the original cutting point of the partition without needing to continue from the open endpoint; therefore, no new cutting path is generated for this partition. When the number n is two, the partition contour has been completely cut, and there are no open cuts requiring continuation. Recovery does not require cutting the partition again, nor is a new cutting path generated for it. In both cases, the contour boundary of the partition is considered closed.

[0050] Furthermore, the regeneration of the cutting path includes: obtaining the tangent direction of the contour boundary at the open endpoint; determining the side of the tangent direction that is away from the already cut contour in the partition as the uncut area; generating a guide segment from the open endpoint along the tangent direction toward the uncut area, and connecting the guide segment with the unexecuted portion of the initial cutting trajectory or the detour trajectory to obtain the cutting path.

[0051] Specifically, when the quantity n is one, the open endpoint and the cut contour are located at opposite ends of the partition contour. The tangent direction of the contour boundary at the open endpoint is obtained, i.e., the tangent direction extending from the partition contour to the open endpoint is obtained. Specifically, the extension direction of the line segment adjacent to the open endpoint at the open endpoint is taken as the tangent direction. The tangent direction contains two opposite directions. One direction points along the contour towards the uncut contour portion within the partition from the open endpoint to the projection point, with the cut contour located on one side of this direction's extension. The other direction points away from the partition contour, towards the uncut material outside the partition contour; no cut contour exists on this side. The side of the tangent direction away from the cut contour is defined as the uncut region, and the subsequently generated guide segments are arranged within this region.

[0052] In practical applications, a guide segment is generated from the open endpoint along the tangent direction towards the uncut area. This means a segment of length Ld extends from the open endpoint in a direction away from the already cut contour, with the end of the guide segment landing on the material in the uncut area. The introduction length Ld is set based on the size of the hole formed by the ablation of the material during perforation, and is greater than the hole radius to maintain a distance between the perforation point and the open endpoint and the already cut contour. The guide segment is connected to the unexecuted portion of the initial cutting trajectory or bypass trajectory. That is, using the open endpoint as the connection point, the guide segment is connected end-to-end to the unexecuted portion of the trajectory in that section to obtain the cutting path. During resuming cutting, the laser head first moves idle to the end of the guide segment, perforates at the end to initiate cutting, cuts along the guide segment to the open endpoint, and then cuts along the unexecuted portion of the trajectory from the open endpoint to the projection point, connecting with the already cut contour. Since the holes formed by perforation are located in the uncut area away from the already cut contour, the heat from perforation and the holes will not damage the already cut contour or the contour to be cut in that section, thus ensuring the cut quality at the breakpoint continuation point.

[0053] Furthermore, it also includes: when cutting is interrupted, recording the temperature of the heat-affected zone at the moment of interruption; when cutting is resumed, if the temperature of the heat-affected zone is higher than the preset temperature, cutting the cutting sections that do not fall into the heat-affected zone is cut first, and cutting the cutting sections that fall into the heat-affected zone is cut only after the temperature of the heat-affected zone is no higher than the preset temperature.

[0054] Specifically, the temperature of the heat-affected zone is recorded at the moment of interruption. That is, the controller records the temperature of each heat-affected zone that has not yet fully cooled at the moment of interruption, and writes it along with the partition identifier into non-volatile memory. The temperature of the heat-affected zone is calculated according to the cooling decay law. Let tm be the time from the completion of partition cutting to the moment of interruption for a certain heat-affected zone, Tq be the peak temperature, Tb be the ambient temperature, and τ be the cooling time constant. Then, the temperature Tm of the heat-affected zone at the moment of interruption is: Tm = Tb + (Tq Tb) × e ( tm / τ) When resuming the cutting process, let the interruption duration be tz. Then, the temperature Tr of the heat-affected zone at the time of resumption is: Tr = Tb + (Tm Tb) × e ( tz / τ) To determine whether a cut section falls within the heat-affected zone, the same method used during the cutting process is applied: if the shortest distance from the starting or ending point of the cut section to the corresponding section outline in the heat-affected zone is less than the heat diffusion range R, then the section is considered to fall within the heat-affected zone.

[0055] In practical applications, when the temperature Tr at the recovery time is higher than the preset temperature Tp, it indicates that the heat-affected zone has not yet cooled down sufficiently. Cutting immediately within this zone would cause overheating. In this case, cut the sections that have not yet fallen into the heat-affected zone first, followed by the sections that have fallen into the heat-affected zone. The remaining waiting time tg = τ × ln((Tr) Tb) / (Tp Tb)) indicates that the controller accumulates the elapsed time while cutting the remaining partitions. When the accumulated time reaches tg, and the temperature of the heat-affected zone is not higher than the preset temperature Tp, the partitions falling into the heat-affected zone are then scheduled for cutting. When the temperature Tr at the recovery time is not higher than the preset temperature Tp, it means that the heat-affected zone has cooled down during the interruption, and there is no need to adjust the cutting order for the heat-affected zone; the cutting can be executed directly according to the adjusted cutting order.

[0056] S106, according to the adjusted cutting sequence, the bypass trajectory, or the cutting path, control the laser head to continue performing the cutting operation.

[0057] Specifically, during the resumption of cutting, the controller determines the next partition to be cut based on the adjusted cutting order. It then queries a lookup table according to the partition identifier of that partition to retrieve the starting and ending coordinates of the cutting start and end points stored in the corresponding storage unit, and controls the laser head movement accordingly. If the next partition to be cut has a cutting path, the laser head is controlled to first move idle to the end of the guide line segment in the cutting path, then cut along the guide line segment to the open endpoint after piercing, and then continue cutting along the unexecuted trajectory. If the starting position of the next partition to be cut falls into the heat-affected zone and a detour is used, the laser head is controlled to move idle along the detour trajectory to the cutting start or end point of that partition before starting cutting. The cutting start and end points of the remaining partitions are read from their respective storage units, and they are cut sequentially according to the adjusted cutting order. After each partition is cut, the laser head's dwell position is updated to the current reference position for determining the cutting order of the remaining partitions.

[0058] As can be seen from the above, the laser cutting point storage and trajectory automatic generation control method of this embodiment divides the workpiece contour into multiple cutting partitions and allocates storage units for point data management. The initial cutting sequence is determined according to the straight-line distance. During the cutting process, the heat-affected zone is determined according to the contour length and cutting speed of the previous partition, and the cooling waiting time and detour idle time are compared to dynamically adjust the cutting sequence or generate a detour trajectory. When the cutting is interrupted, the position information is recorded, and when the cutting is resumed, the cutting path is regenerated to the uncut area according to the open endpoint of the cut contour. This solves the problems of long cutting path idle time, large thermal damage, and easy waste generation when continuing cutting at the breakpoint in the prior art. It has the advantages of being able to realize structured storage of cutting partitions, online avoidance of heat-affected zones, and waste-free continuing cutting at the breakpoint, thereby improving cutting efficiency, finished product quality and process continuity.

[0059] Furthermore, this application also proposes a control system for storing laser cutting points and automatically generating trajectories, such as... Figure 4 As shown, the system includes an acquisition and storage module 401, a trajectory generation module 402, an adjustment module 403, and a control module 404. Those skilled in the art will understand that the above modules can be implemented by software programs, hardware circuits, or a combination of both; this application does not impose specific limitations in this regard.

[0060] In practical applications, the above modules work together to complete the laser cutting task of complex workpiece contours. Specifically, the acquisition and storage module 401 is responsible for acquiring workpiece contour data, dividing the cutting zones, and structurally storing the point data; the trajectory generation module 402 determines the initial cutting sequence and generates the initial cutting trajectory based on the stored point data; the adjustment module 403 dynamically adjusts the cutting sequence or generates a detour trajectory according to the heat-affected zone during the cutting process, and reconstructs the entry path for resuming cutting at the breakpoint when cutting is interrupted; the control module 404 drives the laser head to perform the cutting operation according to the finally determined trajectory information. The specific workflow of each module will be described in detail below.

[0061] The acquisition and storage module 401 acquires the contour data of the workpiece to be cut, divides the workpiece contour into multiple cutting sections, allocates a storage unit to each section, determines the cutting start point and cutting end point of each cutting section, writes its coordinates into the corresponding storage unit, and records the correspondence between the section identifier and the storage unit. The trajectory generation module 402 determines the initial cutting order of each cutting partition and generates the initial cutting trajectory based on the coordinates of the cutting start point and cutting end point stored in each partition. The adjustment module 403 cuts each cutting partition according to the initial cutting trajectory. During the cutting process, the heat-affected zone generated by the previously cut partition is determined. When the cutting start point or end point of the subsequent partition to be cut falls into this zone, the cooling waiting time and the detour idle time are compared, and the initial cutting sequence is adjusted or a detour trajectory is generated. When the cutting is interrupted, the identifier of the current cutting partition and the position of the laser head at the time of interruption are recorded. When the cutting is resumed, the open endpoint of the contour boundary within the partition is determined according to the recorded position, and a cutting path is regenerated from the open endpoint to the uncut area. The control module 404 controls the laser head to continue performing the cutting operation according to the adjusted cutting sequence, the bypass trajectory, or the cutting path.

[0062] This system can be used to execute the control methods described above for storing laser cutting points and automatically generating trajectories, which will not be elaborated further here.

[0063] In summary, this embodiment of the application achieves structured storage of the cutting partition through the acquisition and storage module 401, generates an initial trajectory based on idle distance optimization through the trajectory generation module 402, achieves online collaborative avoidance of the heat-affected zone and waste-free continuation cutting at breakpoints through the adjustment module 403, and finally completes precise cutting execution through the control module 404. Therefore, this embodiment of the application improves cutting efficiency while effectively reducing the risk of thermal deformation and ensuring process continuity after cutting interruption, significantly improving the finished product quality and production stability of laser cutting of complex workpieces.

[0064] It should also be noted that the module division in the above embodiments is only a logical functional division, and in actual implementation, there may be other division methods. For example, some functions in the acquisition and storage module 401 and the adjustment module 403 may be executed by the same processor, or the trajectory generation module 402 and the adjustment module 403 may be integrated into the same software unit. In addition, the above modules may be deployed in the local controller of the laser cutting equipment or in a cloud server and communicate with the cutting equipment through a network. This application does not make specific limitations in this regard.

[0065] The above description is merely an embodiment of this application and is not intended to limit the scope of protection of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A control method for storing laser cutting points and automatically generating trajectories, characterized in that, include: Obtain the contour data of the workpiece to be cut, divide the workpiece contour into multiple cutting partitions, and allocate a storage unit for each partition; Determine the starting and ending points of each cutting partition, write their coordinates into the corresponding storage unit, and record the correspondence between the partition identifier and the storage unit; Based on the coordinates of the cutting start and cutting end points stored in each partition, the initial cutting order of each cutting partition is determined, and the initial cutting trajectory is generated. Each cutting section is cut according to the initial cutting trajectory; during the cutting process, the heat-affected zone generated by the previously cut section is determined. When the starting point or ending point of the subsequent section to be cut falls into this zone, the cooling waiting time and the detour idle time are compared, and the initial cutting sequence is adjusted or a detour trajectory is generated. When cutting is interrupted, the identifier of the current cutting partition and the position of the laser head at the time of interruption are recorded; when resuming, the open endpoint of the contour boundary within the partition is determined based on the recorded position, and the cutting path is regenerated from the open endpoint to the uncut area. Based on the adjusted cutting sequence, the detour trajectory, or the cutting path, the laser head is controlled to continue performing the cutting operation.

2. The method according to claim 1, characterized in that, The process of dividing the workpiece contour into multiple cutting sections includes: Extract the endpoint coordinates of the line segments in the contour data, and determine the connection relationship between the line segments in the contour based on the coincidence relationship of the endpoint coordinates between adjacent line segments; Based on the connection relationship, calculate the directional difference between adjacent line segments, and mark the connection positions where the directional difference is greater than a preset threshold as corner points; The continuous line segments between adjacent corner points are divided into the same cutting partition.

3. The method according to claim 2, characterized in that, Determining the starting and ending points of each cutting partition includes: For the segment containing the corner point, obtain the extension direction of the line segment adjacent to the corner point; The endpoint of the line segment extending towards the inside of the cutting partition is defined as the cutting start point, and the endpoint of the line segment extending towards the outside of the cutting partition is defined as the cutting end point.

4. The method according to claim 1, characterized in that, Determining the initial cutting order of each cutting partition includes: Use the position where the laser head stops after completing the current cutting section as the current reference position; Calculate the straight-line distance between the current reference position and the cutting start point and cutting end point of the next partition to be cut; The starting point or ending point of the cutting corresponding to the smallest straight-line distance shall be used as the starting point of the next partition to be cut. The position of the starting cutting point is updated to the current reference position, and the starting cutting point of the next partition to be cut is determined based on the updated current reference position, until all partitions are included in the initial cutting sequence.

5. The method according to claim 1, characterized in that, The determination of the heat-affected zone generated by the previously cut partitions includes: Calculate the heat input time required to cut the previously cut partition based on the outline length and cutting speed of the previously cut partition; Based on the heat input duration and the heat dissipation characteristics of the workpiece, the heat diffusion range is determined; taking the outline of the previously cut partition as the center line, the heat diffusion range is extended to both sides of the outline, and the covered strip area is determined as the heat-affected zone.

6. The method according to claim 5, characterized in that, The comparison of cooling waiting time and detour idle time, and the adjustment of the initial cutting sequence or generation of detour trajectory, includes: Based on the heat dissipation characteristics of the material of the workpiece to be cut, the cooling waiting time required for the heat-affected zone to cool to the preset temperature is estimated. Calculate the detour time to reach the cutting start or end point of the subsequent section to be cut by bypassing the heat-affected zone; When the cooling waiting time is less than the detour idle time, the initial cutting sequence is adjusted so that the subsequent partitions to be cut are cut after waiting for the cooling waiting time. When the detour idle time is less than or equal to the cooling waiting time, a detour trajectory is generated to bypass the heat-affected area and reach the subsequent partition to be cut.

7. The method according to claim 6, characterized in that, Also includes: When cutting is interrupted, record the temperature of the heat-affected zone at the moment of interruption; When resuming cutting, if the temperature of the heat-affected zone is higher than the preset temperature, the cutting sections that do not fall into the heat-affected zone are cut first. After the temperature of the heat-affected zone is no higher than the preset temperature, the cutting sections that fall into the heat-affected zone are cut.

8. The method according to claim 1, characterized in that, The recovery process involves determining the open endpoints of the contour boundaries within the partition based on the recorded locations, including: Based on the position of the laser head at the moment of interruption, as well as the positions of the cutting start and cutting end points of the partition, determine the number of parts that have been cut in the cutting start and cutting end points of the partition; When the quantity is one, the cutting start point or cutting end point that has not yet been cut is determined as the open endpoint; When the number is zero or two, the contour boundary of the partition is determined to be closed, and no new entry path is generated for the partition.

9. The method according to claim 8, characterized in that, The regeneration of the cut-in path includes: Obtain the tangent direction of the contour boundary at the open endpoint; The side of the tangent direction that is away from the already cut contour within the partition is defined as the uncut area; A guide segment is generated from the open endpoint along the tangential direction toward the uncut region, and the guide segment is connected to the unexecuted portion of the initial cutting trajectory or the detour trajectory to obtain the cutting path.

10. A control system for storing laser cutting points and automatically generating trajectories, characterized in that, include: The acquisition and storage module acquires the contour data of the workpiece to be cut, divides the workpiece contour into multiple cutting partitions, and allocates a storage unit to each partition. Determine the starting and ending points of each cutting partition, write their coordinates into the corresponding storage unit, and record the correspondence between the partition identifier and the storage unit; The trajectory generation module determines the initial cutting order of each cutting partition and generates the initial cutting trajectory based on the coordinates of the cutting start and cutting end points stored in each partition. The adjustment module cuts each cutting partition according to the initial cutting trajectory. During the cutting process, it determines the heat-affected zone generated by the previously cut partition. When the starting point or ending point of the subsequent partition to be cut falls into this zone, it compares the cooling waiting time with the detour idle time and adjusts the initial cutting order or generates a detour trajectory. When the cutting is interrupted, it records the identifier of the current cutting partition and the position of the laser head at the time of interruption. When resuming, it determines the open endpoint of the contour boundary within the partition based on the recorded position and regenerates the cutting path from the open endpoint to the uncut area. The control module controls the laser head to continue performing the cutting operation according to the adjusted cutting sequence, the detour trajectory, or the cutting path.

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