Forming trajectory planning method and device for laser shock and medium
By using quantitative partitioning and specific scanning trajectory planning, the forming efficiency and accuracy problems of curved regions in laser shock forming were solved, enabling rapid generation and self-optimization of process parameters, and improving the efficiency and accuracy of complex surface processing.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-30
- Publication Date
- 2026-04-10
AI Technical Summary
Existing laser shock forming technology does not fully consider the differences in material deformation mechanism and strain distribution characteristics in different curvature regions when forming complex curved parts, resulting in problems such as low forming efficiency, insufficient precision or local wrinkles. Furthermore, the determination of process parameters depends on time-consuming numerical simulation iterations.
By quantitatively dividing the target surface into zones, combining material properties and curvature characteristics, specific scanning trajectories and process parameters for single/double curvature regions are planned, processing codes are generated, and parameters are corrected through trial processing feedback, thus achieving rapid and accurate forming trajectory planning.
It improves the efficiency and precision of laser shock forming of complex curved surfaces, reduces local stress concentration, and enables rapid generation and self-optimization of process parameters.
Smart Images
Figure CN121837553A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of laser processing technology, and in particular to a method, equipment and computer-readable storage medium for laser shock forming trajectory planning. Background Technology
[0002] Laser shock forming is a novel manufacturing technology that uses the shock wave pressure induced by high-energy pulsed lasers to cause plastic deformation of metal sheets, thereby achieving moldless and flexible forming. This technology applies laser shocks point-by-point or area-by-area to specific areas on the surface of the sheet, accumulating plastic strain to cause the sheet to bend or twist as a whole or in parts, ultimately forming a target three-dimensional curved surface.
[0003] When forming complex curved parts, the surface often contains multiple curvature features, such as single-curvature regions (e.g., cylindrical, conical surfaces) and double-curvature regions (e.g., spherical, saddle-shaped surfaces). Existing laser shock forming trajectory planning methods mostly use a uniform scanning path (e.g., linear scanning, bow-shaped scanning, or spiral scanning) to impact the entire processing area, without fully considering the differences in material deformation mechanisms and strain distribution characteristics in different curvature regions. In single-curvature regions, the material mainly bends along one principal curvature direction, resulting in relatively uniform deformation; while in double-curvature regions, the material bends simultaneously in two principal directions, leading to more complex deformation and uneven strain distribution. Using a uniform impact trajectory may result in low forming efficiency in single-curvature regions, or insufficient forming accuracy, local wrinkles, or overstretching in double-curvature regions. Furthermore, existing methods rely heavily on experience or simple geometric observation when dividing curvature regions, lacking quantitative criteria related to material mechanical properties and plate thickness; and they heavily depend on time-consuming numerical simulation iterations when determining process parameters, limiting the rapid process planning and application efficiency of this technology.
[0004] Therefore, it is necessary to provide a method, device, and medium for laser shock trajectories planning to solve the above-mentioned technical problems. Summary of the Invention
[0005] The purpose of this invention is to provide a method, device, and medium for planning the forming trajectory of laser shock. The specific technical solution is as follows: A method for planning the forming trajectory for laser shock includes the following steps: S1: Obtain the three-dimensional mathematical model of the target surface, divide the region by quantitative partitioning, and obtain the region division result; S2: Plan different forming trajectories according to the regional division results; S3: Based on the divided regions, combined with the curvature characteristics, material properties and expected deformation of the regions, the corresponding process parameters are generated using empirical formulas; S4: Generate processing codes based on the impact trajectory and process parameters of each region; S5: Perform trial processing and compare the measured deformation of the formed part with the target value to generate deviation data. If the deviation data exceeds the threshold, the deviation data is fed back to S3 and the parameters of the empirical formula are corrected until the deviation data does not exceed the threshold. Finally, the processing code is fed back to complete the forming trajectory planning.
[0006] Optionally, in S1, the region is divided by quantitative partitioning, the process of which includes: Divide the target surface into several regions at certain intervals and analyze the principal curvature within each region. and , ; The region is divided into single curvature region, hypercurvature region and transition region according to the determination formula, and connected regions with the same determination result are merged.
[0007] Optionally, in S1, the determination formula includes: Formula for determining the curvature region: If it satisfies If so, then the region is determined to be a region of single curvature. The curvature threshold is expressed as follows: ; in, The first empirical coefficient, The yield strength of the material. The elastic modulus of the material, For the thickness of the board, The minimum bounding rectangle side length or minimum bounding circle diameter of the region's outline; Formula for determining hypercurvature region: If it satisfies ,and If so, then the region is determined to be a hypercurvature region. The hyperbola threshold is expressed as follows: ; in, The second empirical coefficient, ; when If so, the area is determined to be a transitional area.
[0008] Optionally, in S2, different forming trajectories are planned according to the region division results, including: For regions with single curvature, plan a bow-shaped scanning trajectory along the principal curvature direction; For hypercurvature regions, a loop-shaped scanning trajectory is planned that contracts from the region boundary toward the center. For transition regions, a smooth transition is achieved by using a trajectory density gradient or a hybrid trajectory that combines the characteristics of both trajectories.
[0009] Optionally, in S3, process parameters include laser power density, spot overlap rate, and number of impacts.
[0010] Optionally, in S3, the expression for calculating laser power density is as follows: ; in, Indicates laser power density; This represents the average curvature of the region, with the single curvature region taken as... Hypercurvature region ; Indicates the power density coefficient; This represents the combined pressure conversion efficiency of the laser absorption layer and the confinement layer.
[0011] Optionally, in S3, the formula for calculating the spot overlap rate is as follows: ; in, Indicates the baseline overlap rate; Indicates the curvature influence coefficient; Indicates the size of the light spot.
[0012] Optionally, in S3, the expression for calculating the number of impacts is as follows: ; The number of impacts is obtained by rounding up the result of the expression calculation. Indicates the target curvature of the region; Indicates the cumulative deformation coefficient of the material; Indicates the laser pulse width; This indicates the laser power density.
[0013] In addition, the present invention also provides a forming trajectory planning device for laser shock, used to implement the forming trajectory planning method as described above, comprising: Region division module: Used to obtain the three-dimensional mathematical model of the target surface, and to divide the region by quantitative partitioning to obtain the region division result; Forming trajectory planning module: used to plan different forming trajectories according to the region division results; Process parameter generation module: used to generate corresponding process parameters based on the defined regions; Machining code generation module: used to generate machining codes according to the impact trajectory and process parameters of each region; Iterative correction module: Used to perform trial processing, compare the measured deformation of the formed part with the target value, and correct the parameters of the empirical formula until the deviation data does not exceed the threshold, and then feed back the final processing code to complete the forming trajectory planning.
[0014] In addition, the present invention also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described shaping trajectory planning method.
[0015] The application of the technical solution of the present invention has at least the following beneficial effects: This invention provides a method for planning the forming trajectory of laser shock. The method divides the target curved surface into regions, incorporating the material's yield strength, elastic modulus, and plate thickness into the region division to construct a formula for defining the curvature regions. Unlike traditional partitioning methods, this invention introduces a criterion formula directly related to the material's yield strength, elastic modulus, and plate thickness for automatic curvature region partitioning. This elevates the partitioning basis from empirical judgment to quantitative decision-making driven by physical mechanisms, improving the method's universality and reliability.
[0016] The method of this invention bypasses the time-consuming finite element numerical simulation iteration process by establishing analytical empirical formulas from curvature and materials to key process parameters, and realizes rapid prediction and generation of process parameters, which significantly improves the efficiency of process planning for laser shock forming of complex curved surfaces.
[0017] The method of this invention combines targeted trajectory planning with rapidly generated adaptive process parameters, which improves the overall processing efficiency while ensuring the forming accuracy of single / double curvature regions.
[0018] After surface analysis, quantitative partitioning, trajectory planning and parameter parsing, the method of this invention performs trial processing by generating processing code, and further adjusts the parameters of the empirical formula based on the results. This process reserves an interface for feedback calibration, so that the method of this invention can continuously optimize itself through machine learning.
[0019] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0021] Figure 1 This is a flowchart illustrating the steps of the laser shock forming trajectory planning method in a preferred embodiment of the present invention.
[0022] Figure 2 This is a schematic diagram of quantitative region division based on formula in a preferred embodiment of the present invention.
[0023] Figure 3(a) is a schematic diagram of the bow-shaped impact trajectory planned for a single curvature region in a preferred embodiment of the present invention.
[0024] Figure 3(b) is a schematic diagram of the zigzag impact trajectory planned for the hypercurvature region in a preferred embodiment of the present invention.
[0025] Figure 4 This is a panoramic view of the partitioning and trajectory parameter planning of an example component in a preferred embodiment of the present invention. Detailed Implementation
[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.
[0027] Example: like Figure 1 As shown, this embodiment provides a method for planning the forming trajectory of laser shock, including the following steps (S1 to S4): S1: Obtain the three-dimensional mathematical model of the target surface (CAD model can be used in this embodiment), divide the region by quantitative partitioning, and obtain the region division result.
[0028] Specifically, the process of dividing regions through quantitative zoning includes: Divide the target surface into several regions at certain intervals and analyze the principal curvature within each region. and , ; The region is divided into single curvature region, hypercurvature region and transition region according to the determination formula, and connected regions with the same determination result are merged.
[0029] Furthermore, the determination formula includes: Formula for determining the curvature region: If it satisfies If so, then the region is determined to be a region of single curvature. The curvature threshold is expressed as follows: ; in, The first empirical coefficient, The yield strength of the material. The elastic modulus of the material, For the thickness of the board, The minimum bounding rectangle side length or minimum bounding circle diameter of the region's outline; Formula for determining hypercurvature region: If it satisfies ,and If so, then the region is determined to be a hypercurvature region. The hyperbola threshold is expressed as follows: ; in, The second empirical coefficient, ; when If so, the area is determined to be a transitional area.
[0030] It should be noted that, and These are all empirical coefficients; for aluminum alloy materials, The value range is 0.05-0.15. The value range is 0.3-0.7; for titanium alloys, The value range is 0.03-0.1. The value range is 0.25-0.6.
[0031] S2: Plan different forming trajectories according to the regional division results.
[0032] Specifically, different formation trajectories are planned according to the regional division results, including: For single curvature regions, a bow-shaped scanning trajectory is planned along the main curvature direction; this trajectory can effectively generate uniform bending strain along the scanning direction, improving forming efficiency.
[0033] For hypercurvature regions, a zigzag scanning trajectory is planned that contracts from the region boundary toward the center. This trajectory helps to gradually accumulate strain from the periphery toward the center, promotes coordinated deformation of the material in both directions, reduces local stress concentration, and improves forming uniformity and accuracy.
[0034] For transition regions, a smooth transition is achieved by using a trajectory density gradient or a hybrid trajectory that combines the characteristics of both trajectories.
[0035] S3: Based on the divided regions, combined with the curvature characteristics, material properties and expected deformation of the regions, the corresponding process parameters are generated using empirical formulas.
[0036] In this embodiment, the process parameters include laser power density, spot overlap rate, and number of impacts.
[0037] Specifically, the formula for calculating laser power density is as follows: ; in, Indicates laser power density; This represents the average curvature of the region, with the single curvature region taken as... Hypercurvature region ; Indicates the power density coefficient; This represents the combined pressure conversion efficiency of the laser absorption layer and the confinement layer, as shown in this embodiment. The value range is 0.6-0.9.
[0038] Optionally, in S3, the formula for calculating the spot overlap rate is as follows: ; in, In this embodiment, the baseline overlap rate is indicated. The value range is 40-60%; Indicates the curvature influence coefficient; Indicates the size of the light spot.
[0039] Optionally, in S3, the expression for calculating the number of impacts is as follows: ; The number of impacts is obtained by rounding up the result of the expression calculation. Indicates the target curvature of the region; Indicates the cumulative deformation coefficient of the material; Indicates the laser pulse width; This indicates the laser power density.
[0040] S4: Generate processing codes based on the impact trajectory and process parameters of each region.
[0041] In this embodiment, the process of generating the processing code is as follows: The planned impact trajectories for each region are integrated and coordinated with the calculated process parameters to ensure smooth trajectory switching. Based on the control requirements of the selected laser processing system, complete CNC machining code is generated.
[0042] S5: Perform trial processing and compare the measured deformation of the formed part with the target value to generate deviation data. If the deviation data exceeds the threshold, the deviation data is fed back to S3 and the parameters of the empirical formula are corrected until the deviation data does not exceed the threshold. Finally, the processing code is fed back to complete the forming trajectory planning.
[0043] In this embodiment, taking a thin-walled titanium alloy TC4 component for a spacecraft as an example, the thickness of the plate... =1.5mm, part feature dimension =120mm. Material parameters: Yield strength =930MPa, elastic modulus =110 GPa. A circular light spot is used, with a spot diameter of... The selected value is 4mm.
[0044] In S1, the model of the target surface is imported into the CAD software, and the mesh is discretized using empirical coefficients calibrated with TC4. =0.06, =0.4; Further, calculate the single curvature threshold and the hypercurvature threshold. , .like Figure 2 As shown, in this embodiment, the final division results in a single curvature region A, a hypercurvature region B, and a transition region C.
[0045] In S2, a bow-shaped path as shown in Figure 3(a) and a concentric circular meander-shaped path as shown in Figure 3(b) are constructed. In the transition region C, a linear transition path from the bow shape to the outermost meander shape is adopted.
[0046] In S3, first set the common process parameters: laser pulse width 17ns, spot size Φ3mm. Other process parameters were obtained through basic experimental calibration: =0.85, =50%, =1.2, =0.002. The curvature region A is calculated using the process parameter calculation expression in the above steps: , The pulse energy is 18.2 J, the spot overlap rate is 45%, and the number of impacts is 4; hypercurvature region B: , The pulse energy was 16.6 J, the spot overlap rate was 47%, and the number of impacts was 2.
[0047] In S4, the process of generating processing code is as follows: The impact trajectories and process parameters of the single-curvature region A, double-curvature region B, and transition region C are integrated in the order A->C->B. Based on the controller format of the six-axis laser shock forming machine tool, a CNC machining program file, i.e., machining code, containing information such as coordinate points, laser switches, energy settings, and scanning speed, is generated. The overall planning view is as follows: Figure 4 As shown.
[0048] Finally, the above processing code was used for experimental processing and verification. The 3D scanning detection results showed that the relative error of the forming curvature in the single curvature region A was +3.2%, and the maximum shape deviation in the double curvature region B was 0.10 mm. The forming results of all regions met the design accuracy requirements, verifying the accuracy and effectiveness of the method for rapid parameter planning in this embodiment.
[0049] In addition, this embodiment also provides a forming trajectory planning device for laser shock, used to implement the forming trajectory planning method as described above, including: Region division module: Used to obtain the three-dimensional mathematical model of the target surface, and to divide the region by quantitative partitioning to obtain the region division result; Forming trajectory planning module: used to plan different forming trajectories according to the region division results; Process parameter generation module: used to generate corresponding process parameters based on the defined regions; Machining code generation module: used to generate machining codes according to the impact trajectory and process parameters of each region; Iterative correction module: Used to perform trial processing, compare the measured deformation of the formed part with the target value, and correct the parameters of the empirical formula until the deviation data does not exceed the threshold, and then feed back the final processing code to complete the forming trajectory planning.
[0050] It should be noted that computer program code for performing the operations of this application can be written in one or more programming languages or a combination thereof. These programming languages include object-oriented programming languages—such as Java, Smalltalk, and C++—as well as conventional procedural programming languages—such as the "C" language or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a Local Area Network (LAN) or a Wide Area Network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).
[0051] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions indicated in the blocks may occur in a different order than those indicated in the drawings. For example, two consecutively indicated blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in the block diagrams and / or flowcharts, and combinations of blocks in the block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or operation, or using a combination of dedicated hardware and computer instructions.
[0052] The modules described in the embodiments of this application can be implemented in software or hardware. The names of the modules do not necessarily limit the functionality of the unit itself.
[0053] In addition, this embodiment also provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the steps of the above-described shaping trajectory planning method.
[0054] The readable storage medium provided in this application is a computer-readable storage medium that stores computer-readable program instructions (i.e., a computer program) for executing the above-described forming trajectory planning method, which can optimize parameter generation efficiency and improve forming trajectory planning speed. Compared with the prior art, the beneficial effects of the computer-readable storage medium provided in this application are the same as the beneficial effects of the forming trajectory planning method provided in the above embodiments, and will not be repeated here.
[0055] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.
Claims
1. A method for planning the forming trajectory for laser shock, characterized in that, Includes the following steps: S1: Obtain the three-dimensional mathematical model of the target surface, divide the region by quantitative partitioning, and obtain the region division result; S2: Plan different forming trajectories according to the regional division results; S3: Based on the divided regions, combined with the curvature characteristics, material properties and expected deformation of the regions, the corresponding process parameters are generated using empirical formulas; S4: Generate processing codes based on the impact trajectory and process parameters of each region; S5: Perform trial processing and compare the measured deformation of the formed part with the target value to generate deviation data. If the deviation data exceeds the threshold, the deviation data is fed back to S3 and the parameters of the empirical formula are corrected until the deviation data does not exceed the threshold. Finally, the processing code is fed back to complete the forming trajectory planning.
2. The method for planning the forming trajectory for laser shock as described in claim 1, characterized in that, In S1, the region is divided through quantitative partitioning. The process includes: Divide the target surface into several regions at certain intervals and analyze the principal curvature within each region. and , ; The region is divided into single curvature region, hypercurvature region and transition region according to the determination formula, and connected regions with the same determination result are merged.
3. The method for planning the forming trajectory for laser shock as described in claim 2, characterized in that, In S1, the determination formula includes: Formula for determining the curvature region: If it satisfies If so, then the region is determined to be a region of single curvature. The curvature threshold is expressed as follows: ； in, The first empirical coefficient, The yield strength of the material. The elastic modulus of the material, For the thickness of the board, The minimum bounding rectangle side length or minimum bounding circle diameter of the region's outline; Formula for determining hypercurvature region: If it satisfies ,and If so, then the region is determined to be a hypercurvature region. The hyperbola threshold is expressed as follows: ； in, The second empirical coefficient, ; when If so, the area is determined to be a transitional area.
4. The method for planning the forming trajectory for laser shock as described in claim 3, characterized in that, In S2, different forming trajectories are planned according to the region division results, including: For regions with single curvature, plan a bow-shaped scanning trajectory along the principal curvature direction; For hypercurvature regions, a loop-shaped scanning trajectory is planned that contracts from the region boundary toward the center. For transition regions, a smooth transition is achieved by using a trajectory density gradient or a hybrid trajectory that combines the characteristics of both trajectories.
5. The method for planning the forming trajectory for laser shock as described in claim 4, characterized in that, In S3, the process parameters include laser power density, spot overlap rate, and number of impacts.
6. The method for planning the forming trajectory for laser shock as described in claim 5, characterized in that, In S3, the expression for calculating laser power density is as follows: ； in, Indicates laser power density; This represents the average curvature of the region, with the single curvature region taken as... Hypercurvature region ; Indicates the power density coefficient; This represents the combined pressure conversion efficiency of the laser absorption layer and the confinement layer.
7. The method for planning the forming trajectory for laser shock as described in claim 5, characterized in that, In S3, the formula for calculating the spot overlap rate is as follows: ； in, Indicates the baseline overlap rate; Indicates the curvature influence coefficient; Indicates the size of the light spot.
8. The method for planning the forming trajectory for laser shock as described in claim 5, characterized in that, In S3, the formula for calculating the number of impacts is as follows: ； The number of impacts is obtained by rounding up the result of the expression calculation. Indicates the target curvature of the region; Indicates the cumulative deformation coefficient of the material; Indicates the laser pulse width; This indicates the laser power density.
9. A shaping trajectory planning device for laser shock, characterized in that, A method for implementing the forming trajectory planning method as described in any one of claims 1-8 includes: Region division module: Used to obtain the three-dimensional mathematical model of the target surface, and to divide the region by quantitative partitioning to obtain the region division result; Forming trajectory planning module: used to plan different forming trajectories according to the region division results; Process parameter generation module: used to generate corresponding process parameters based on the defined regions; Machining code generation module: used to generate machining codes according to the impact trajectory and process parameters of each region; Iterative correction module: Used to perform trial processing, compare the measured deformation of the formed part with the target value, and correct the parameters of the empirical formula until the deviation data does not exceed the threshold, and then feed back the final processing code to complete the forming trajectory planning.
10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, implements the steps of the shaping trajectory planning method according to any one of claims 1 to 8.