A method and system for designing a lightweight topological structure inertial measurement unit (IMU) platform model by additive manufacturing

Abstract

The application provides a kind of additive manufacturing lightweight topology structure inertial measurement unit platform model design method and system, it is related to additive manufacturing and lightweight structure design technical field, including, the mechanical property requirement data and size parameter data of target component are acquired by sensor, preliminary topology structure model is constructed based on the mechanical property requirement data and size parameter data;The additive manufacturing lightweight topology structure inertial measurement unit platform model design method and system, the overhanging structure is identified by space geometry determination to the support area of lightweight topology structure, the matching support structure is generated, the printing path planning is carried out in combination with specific manufacturing constraint, the equal-thickness slicing strategy with fixed layer thickness as the only increment is adopted, the support structure is discretized into scanning path code layer by layer from printing substrate to printing top end, so that the stress of support and main structure is more uniform in forming process, interlayer fusion is more stable, the forming precision and surface quality of inertial measurement unit platform are improved.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing and lightweight structure design technology, specifically to a method and system for designing a lightweight topological inertial navigation system platform model using additive manufacturing. Background Technology

[0002] Additive manufacturing, an advanced manufacturing technology, directly constructs three-dimensional objects by layer-by-layer deposition and is widely used in aerospace, automotive, medical, and electronics industries. Compared to traditional subtractive manufacturing, additive manufacturing offers greater flexibility in constructing complex shapes and provides significant structural freedom. Lightweight design using additive manufacturing technology optimizes material distribution and structural morphology, reducing material usage and increasing component strength, stiffness, and weight. This characteristic gives additive manufacturing advantages in improving production efficiency, reducing energy consumption, and lowering manufacturing costs. In aerospace and automotive fields, lightweight design plays a crucial role in improving performance and saving fuel.

[0003] However, existing lightweight design methods in additive manufacturing have a core problem. Current technologies fail to fully consider the manufacturing constraints of additive manufacturing during topology optimization. Traditional topology optimization techniques are mostly based on ideal assumptions, assuming uniform material distribution. However, in additive manufacturing, the material distribution is limited by layer stacking, making ideal continuity impossible. The ideal lightweight structure design obtained through topology optimization is difficult to directly apply to additive manufacturing. Furthermore, in additive manufacturing, the design of the support structure and the selection of the number of printing layers affect the final product quality; these factors are not effectively considered in traditional optimization models. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method and system for designing lightweight topology inertial navigation system (INS) platform models using additive manufacturing. The technical problem this invention aims to solve is: how to achieve a balance between lightweight design and manufacturability of the INS platform through topology modeling and simulated annealing topology optimization.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solution: a method and system for designing a lightweight topology inertial navigation system platform model using additive manufacturing, comprising: S1. acquiring mechanical performance requirement data and dimensional parameter data of the target component through sensors, and constructing a preliminary topology model based on the mechanical performance requirement data and dimensional parameter data.

[0006] S2. Obtain specific manufacturing constraints in the additive manufacturing process by pre-setting manufacturing parameters, preprocess the preliminary topology model based on the specific manufacturing constraints, and form an additive manufacturing optimization model through the preprocessing.

[0007] S3. Based on the specific manufacturing constraints, the additive manufacturing optimization model is topologically optimized to obtain a lightweight topology. The topology optimization includes particle swarm optimization algorithm and simulated annealing method.

[0008] S4. Perform spatial geometry determination on the support region of the lightweight topology, and generate the support structure through the spatial geometry determination.

[0009] S5. Based on the specific manufacturing constraints, the support structure is printed with equal thickness, and the final printing strategy is formed through the equal thickness printing.

[0010] Preferably, the mechanical performance requirements data include stress and strain, the dimensional parameter data includes component geometry and component thickness, the construction uses stress and strain as material distribution rules, and the component geometry and component thickness as geometry control rules.

[0011] Preferably, the specific manufacturing constraints include printing accuracy, material properties, support structure requirements, and interlayer adhesion.

[0012] Preferably, the preprocessing includes the following steps: S21. Based on the printing accuracy, the minimum feature size of the preliminary topology model is eliminated; based on the support structure requirements, the overhanging area of ​​the preliminary topology model is reconstructed; based on the material properties and interlayer adhesion, the spacing of the preliminary topology model is fused; and a material distribution model is formed through the elimination, overhanging area reconstruction and fusion.

[0013] S22. Perform printing path planning on the material distribution model. The printing path planning discretizes the material distribution model into printing layers according to the specific manufacturing constraints, plans the movement trajectory of the printing layers, generates scanning path codes based on the planning, and performs process parameter matching on the scanning path codes to form an additive manufacturing optimization model.

[0014] Preferably, the particle swarm optimization algorithm performs global iterative optimization on the additive manufacturing optimization model. The global iterative optimization aims to minimize the amount of material used. The global iterative optimization simulates the random motion and group cooperation of particles in the solution space based on specific manufacturing constraints. The additive manufacturing optimization model is iterated based on the simulation process, and an optimized topology model is formed through the iteration.

[0015] Preferably, the simulated annealing method fine-tunes the optimized topology model, forms a locally optimized topology based on the fine-tuning, and performs geometric smoothing on the locally optimized topology to form a lightweight topology. The geometric smoothing rounds the sharp interior corners of the locally optimized topology, and the minimum radius of curvature of the rounded corners is set within the range of 0.15mm to 0.3mm. The fine-tuning includes the following steps: S31. The optimized topology model is used to identify regions to form characteristic structural regions, which include high-load regions, stress concentration regions and unstable regions.

[0016] S32. The high-load area is structurally reinforced by increasing the material density of the high-load area and forming a reinforced structural area based on the material density. The stress concentration area is stress-buffered to form a stress-buffered area. The stress-buffered area uses a gradient material transition. Local support ribs are provided to the unstable area to form a stable topological area.

[0017] S33. Integrate the reinforced structural region, stress buffer region, and stable topology region to form a lightweight topology.

[0018] Preferably, the lightweight topology includes a biomimetic lattice network, a variable density filler, and a porous support skeleton.

[0019] Preferably, the spatial geometry determination extracts the angle between the surface of the support area and the horizontal direction. When the angle is less than 45 degrees, the support area is determined to be a suspended structure area, and a support structure is generated based on the suspended structure area.

[0020] Preferably, the uniform thickness printing uses a fixed layer thickness as the only increment, and the support structure is sliced ​​based on the unique increment. The slicing order is from the printed substrate to the printed top, and the fixed layer thickness ranges from 0.05 mm to 0.2 mm.

[0021] A design system for a lightweight additive manufacturing topology inertial navigation system platform model includes: Topology construction module: used to acquire mechanical performance requirements and dimensional parameters of the target component through sensors, and to construct a preliminary topology model based on the mechanical performance requirements and dimensional parameters.

[0022] Manufacturing constraint preprocessing module: used to obtain specific manufacturing constraints in the additive manufacturing process through preset manufacturing parameters, preprocess the preliminary topology model based on the specific manufacturing constraints, and form an additive manufacturing optimization model through the preprocessing.

[0023] Topology optimization solution module: used to perform topology optimization on the additive manufacturing optimization model, and generate a lightweight topology based on the topology optimization. The topology optimization is based on the specific manufacturing constraints and includes particle swarm optimization algorithm and simulated annealing method.

[0024] Support structure generation module: used to perform spatial geometry determination on the support area of ​​the lightweight topology, and generate the support structure through the spatial geometry determination.

[0025] Printing strategy planning module: used to perform equal-thickness printing on the support structure, and to form a final printing strategy through equal-thickness printing, which is based on the specific manufacturing constraints.

[0026] This invention provides a method and system for designing a lightweight additive manufacturing topology structure inertial navigation system (INS) platform model. It offers the following advantages:

[0027] This invention introduces mechanical performance requirements and dimensional parameters during the topology modeling stage, and combines them with specific manufacturing constraints such as printing accuracy, material properties, support structure requirements, and interlayer adhesion to preprocess the initial topology model and construct an additive manufacturing optimization model. Then, it uses a particle swarm optimization algorithm with the goal of minimizing material usage for global iterative optimization, combined with local fine-tuning and geometric smoothing using simulated annealing, to obtain a lightweight topology that meets the stiffness and strength requirements of the inertial navigation system. This achieves the integration and unification of lightweight design and additive manufacturing process constraints, and solves the problem that existing topology optimization results are difficult to directly use in additive manufacturing and require a lot of post-processing modifications and repeated process trials.

[0028] This additive manufacturing method and system for designing lightweight topology inertial navigation system (INS) platform models identifies and generates matching support structures by spatially geometrically determining the support area of ​​the lightweight topology and identifying the overhanging structure. It then combines specific manufacturing constraints with printing path planning and process parameter matching. Employing a uniform thickness slicing strategy with a fixed layer thickness as the sole increment, the support structure is discretized layer by layer from the printing substrate to the printing top into scanning path codes. This results in more uniform stress distribution and more stable interlayer fusion between the support and the main structure during the forming process, improving the forming accuracy and surface quality of the INS platform, reducing support volume and post-processing workload, shortening the processing cycle, and lowering manufacturing costs. Attached Figure Description

[0029] Figure 1 Flowchart of design methodology for lightweight additive manufacturing topology inertial navigation system platform model; Figure 2 This is a flowchart of the preprocessing process of the present invention; Figure 3 This is a flowchart of the topology optimization process of the present invention; Figure 4 This is the generation determination diagram for the support structure of the present invention; Figure 5 This is a diagram illustrating the thickness printing strategy of the present invention. Detailed Implementation

[0030] 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1 like Figure 1-5 As shown, this invention provides a method and system for designing a lightweight additive manufacturing topology inertial navigation system platform model, including: S1. Acquiring mechanical performance requirement data and dimensional parameter data of the target component through sensors, and constructing a preliminary topology model based on the mechanical performance requirement data and dimensional parameter data. The mechanical performance requirement data includes stress and strain, and the dimensional parameter data includes the component's geometric dimensions and thickness. A model is constructed with stress and strain as material distribution rules and the component's geometric dimensions and thickness as geometric shape control rules.

[0032] S2. Obtain specific manufacturing constraints in the additive manufacturing process by setting manufacturing parameters. Preprocess the initial topology model based on these constraints to form an optimized additive manufacturing model. Specific manufacturing constraints include printing accuracy, material properties, support structure requirements, and interlayer adhesion. The preprocessing includes the following steps:

[0033] S21. Based on printing accuracy, the minimum feature size of the preliminary topology model is eliminated. Based on the support structure requirements, the overhanging area of ​​the preliminary topology model is reconstructed. Based on material properties and interlayer adhesion, the spacing of the preliminary topology model is fused. Through elimination, overhanging area reconstruction and fusion, a material distribution model is formed.

[0034] S22. Perform printing path planning on the material distribution model. The printing path planning discretizes the material distribution model into printing layers according to specific manufacturing constraints, plans the movement trajectory of the printing layers, generates scanning path codes based on the planning, and performs process parameter matching on the scanning path codes to form an additive manufacturing optimization model.

[0035] S3. Based on specific manufacturing constraints, topology optimization is performed on the additive manufacturing optimization model to obtain a lightweight topology. Topology optimization includes particle swarm optimization (PSO) and simulated annealing. PSO performs global iterative optimization on the additive manufacturing optimization model, with the goal of minimizing material usage. Global iterative optimization simulates the random motion and swarm cooperation of particles in the solution space based on specific manufacturing constraints. The simulation process iterates through the additive manufacturing optimization model to form an optimized topology model.

[0036] After discretizing the design domain of the inertial navigation system (INS) platform using a 2mm-3mm grid, 1800 representative elements were selected as design variables, each corresponding to a material density coefficient. The value ranges from 0.1 to 1.0 and is used to represent the degree of material retention in the region. The structural mass is calculated using the density of aluminum alloy AlSi10Mg as 2.68 g / cm³.

[0037] The objective function for topology optimization is set as minimizing the structural mass while satisfying mechanical and manufacturing constraints, specifically: in, To minimize structural mass while satisfying mechanical and manufacturing constraints.

[0038] The constraints include: Under the three load conditions, the maximum displacement of the mounting surface shall not exceed 0.12 mm, the maximum equivalent stress shall not exceed 180 MPa, and the first natural frequency shall not be lower than 250 Hz.

[0039] To meet manufacturing constraints, the particle swarm parameters are set as follows: Number of particles N=40, maximum number of iterations =80, the inertia weight w decreases linearly from 0.9 to 0.4, and the individual learning factor... =2.0, group learning factor =2.0.

[0040] In each generation, particles that do not meet the manufacturing constraints are penalized and their fitness is increased by 20%-50%.

[0041] After the initial population was randomly generated, the initial average structural mass was calculated to be approximately 2.35 kg, with stress and displacement fluctuating around allowable values. As iterations progressed, around the 40th generation, the mass of the optimal solution decreased to approximately 1.72 kg. After 80 generations of convergence, the optimal solution mass stabilized at approximately 1.68 kg, the first natural frequency increased to 263 Hz, the maximum displacement decreased to 0.10 mm, and the maximum equivalent stress was approximately 168 MPa, satisfying the set mechanical performance constraints and specific manufacturing constraints.

[0042] Simulated annealing is used to fine-tune the optimized topology model, forming a locally optimized topology. Geometric smoothing is then applied to this locally optimized topology to create a lightweight topology. Geometric smoothing rounds the sharp interior corners of the locally optimized topology, with the minimum radius of curvature set between 0.15mm and 0.3mm. The fine-tuning includes the following steps: S31. Region identification is performed on the optimized topology model to form characteristic structural regions, including high-load regions, stress concentration regions, and unstable regions.

[0043] S32. Structural reinforcement is carried out in high-load areas. The material density of high-load areas is increased to form a reinforced structural area. Stress buffering is carried out in stress concentration areas to form a stress buffer area. The stress buffering adopts a gradual material transition. Local support ribs are provided in unstable areas to form a stable topological area.

[0044] S33. Integrate the reinforced structural region, stress buffer region, and stable topological region to form a lightweight topological structure.

[0045] Region identification and differentiation processing are performed on the optimized topology model: Regions with equivalent stress greater than 0.8 × 180 MPa are defined as high-load regions, accounting for approximately 18% of the volume fraction. Adjacent regions with a stress gradient change rate exceeding 30% are defined as stress concentration regions, primarily distributed at stiffener-plate transitions and opening edges. Ribs and cantilever members with a slenderness ratio greater than 20 are defined as unstable regions.

[0046] The following measures will be taken for the aforementioned areas: High-load area structural reinforcement: Material densification is performed on identified high-load areas to increase the corresponding density coefficient. The lower limit was increased from 0.5 to 0.8, and the local beam thickness was increased by 0.5mm-1.0mm, which increased the regional stiffness by about 12%.

[0047] Stress concentration area stress buffer: Gradual material transition and geometric transition are introduced at the junction of hole edge and stiffener plate, changing the original right angle transition to a transition zone of 0.6mm-1.2mm, and sharp inner corners are uniformly rounded in geometric modeling, with the rounded corner radius controlled within the range of 0.15mm-0.30mm.

[0048] To stabilize the unstable area, add 1.5mm thick local support ribs or diagonal braces between the slender ribs and the base plate, with the spacing between adjacent support ribs controlled at 8mm-12mm, to improve the area's resistance to instability.

[0049] S4. Perform spatial geometry determination on the support region of the lightweight topology, and generate the support structure based on the spatial geometry determination. The lightweight topology includes a biomimetic lattice network, a variable density infill, and a porous support skeleton. The spatial geometry determination extracts the angle between the surface of the support region and the horizontal direction. When the angle is less than 45 degrees, the support region is determined to be a suspended structure region, and the support structure is generated based on the suspended structure region.

[0050] S5. Based on specific manufacturing constraints, perform constant-thickness printing on the support structure to form the final printing strategy. Constant-thickness printing uses a fixed layer thickness as the only increment. The support structure is sliced ​​based on this unique increment, with the slicing order from the printed substrate to the top of the printed structure. The fixed layer thickness ranges from 0.05 mm to 0.2 mm.

[0051] A design system for a lightweight additive manufacturing topology inertial navigation system platform model includes: Topology construction module: Used to acquire mechanical performance requirements and dimensional parameters of the target component through sensors, and to construct a preliminary topology model based on the mechanical performance requirements and dimensional parameters.

[0052] Manufacturing constraint preprocessing module: used to obtain specific manufacturing constraints in the additive manufacturing process through preset manufacturing parameters, preprocess the preliminary topology model based on the specific manufacturing constraints, and form an additive manufacturing optimization model through preprocessing.

[0053] Topology optimization solution module: used to perform topology optimization on additive manufacturing optimization models, generate lightweight topology structures based on topology optimization, and topology optimization is based on specific manufacturing constraints. Topology optimization includes particle swarm optimization algorithm and simulated annealing method.

[0054] Support structure generation module: used to perform spatial geometry determination on the support area of ​​lightweight topology and generate support structure through spatial geometry determination.

[0055] Printing strategy planning module: used to print the support structure with equal thickness, and to form the final printing strategy through equal thickness printing. Equal thickness printing is based on specific manufacturing constraints.

[0056] Example 2 This embodiment focuses on a certain type of inertial navigation system platform. Based on measured mechanical properties and dimensional parameters, a preliminary topological structure model is constructed. Specific manufacturing constraints such as printing accuracy and material properties are introduced for preprocessing and printing path planning, forming an optimized model for additive manufacturing.

[0057] 1. Obtaining the mechanical properties and dimensional parameters of the target component and constructing a preliminary topology model. A certain type of inertial navigation system (INS) platform was selected as the target component. The platform has an approximate rectangular plate structure with a mounting surface size of 220mm × 180mm and an overall height of 55mm. It has several mounting holes and cavities inside for arranging inertial devices and connectors.

[0058] Strain gauges and triaxial accelerometers were placed on the original solid structure of the target component to test the stress conditions of the inertial navigation system (INS) platform under typical operating conditions. Typical operating conditions included:

[0059] Condition 1: 5g positive impact load in the X direction; Condition 2: 5g positive impact load in the Y direction; Condition 3: 3g vibration load in the Z direction, frequency 80Hz, acceleration amplitude 3g.

[0060] Under the above operating conditions, the maximum principal stress and corresponding strain values ​​at the critical cross-sections were obtained through strain testing. In operating condition one, the maximum principal stress at a critical cross-section at the edge of the mounting surface was 145 MPa, with a corresponding strain of 1.15 × 10⁻³. In operating condition two, the maximum principal stress at the same cross-section was 138 MPa, with a corresponding strain of 1.08 × 10⁻³. Based on the experimental and design requirements, the allowable stress of the inertial navigation system's material was determined. The allowable strain is set at 180 MPa. Set to 1.5 × 10⁻³, the mechanical performance requirements data are generated, including:

[0061] The maximum stress shall not exceed 180 MPa, the maximum strain shall not exceed 1.5 × 10⁻³, and the first natural frequency shall not be lower than 250 Hz.

[0062] The dimensional parameters of the target component were obtained from design drawings and 3D measurements. Using the inertial navigation system's mounting surface as a reference, its length and width were measured to be 220mm and 180mm respectively. The initial thickness of the base plate was 8mm, the sidewall thickness was 6mm, the internal cavity wall thickness was 4mm, the mounting hole diameter ranged from 6mm to 12mm, and the threaded hole diameter ranged from M4 to M6. When constructing the topology model, the mounting surface and bolt connection area were defined as reserved areas, with a minimum reserved thickness of 6mm set to ensure assembly rigidity and connection reliability.

[0063] Based on the aforementioned mechanical performance requirements and dimensional parameters, the working domain of the inertial navigation system (INS) platform is discretized into a three-dimensional finite element design domain, with mesh element side lengths ranging from 2mm to 3mm. The equivalent stress σe and equivalent strain εe of the elements are used as control quantities for the material distribution rules, and a material distribution function ρ( , The material density coefficient is defined by normalizing stress and strain:

[0064] in, Take 0.1, Taking 1.0, when the element stress and strain are much lower than the allowable value, ρ approaches 0.1, corresponding to the area where material can be reduced. When it approaches or exceeds the allowable value, ρ approaches 1.0, requiring preservation or reinforcement. Using the component's geometric dimensions and thickness constraints as geometric shape control rules, the following boundary conditions are set for the design domain: the bottom contour must not shrink, the mounting hole diameter must not decrease, and the minimum local thickness at any location must not be less than 3mm. Based on the above material distribution rules and geometric shape control rules, a preliminary topological model of the inertial navigation system platform is constructed, serving as the starting structure for subsequent additive manufacturing optimization.

[0065] 2. Acquisition and preprocessing of specific manufacturing constraints to form an additive manufacturing optimization model This embodiment uses aluminum alloy as the additive manufacturing material and employs selective laser melting (SLM) technology. The nominal forming accuracy of the equipment is ±0.05 mm, and the laser spot diameter is 80 μm. Based on the equipment technical manual and process test results, the preset manufacturing parameters include:

[0066] The minimum allowable forming feature size is 0.6 mm, the recommended minimum aperture is 1.0 mm, the recommended layer thickness range is 0.03 mm to 0.05 mm, the suitable linear energy density range is 60 J / mm³ to 90 J / mm³, and the linear shrinkage of the material is approximately 0.8% to 1.0%.

[0067] Taking into account printing accuracy, material properties, support structure requirements, and interlayer adhesion, the specific manufacturing constraints are summarized as follows: Printing accuracy constraints: Unit size, hole diameter, and rib thickness must not be less than 0.6mm. Material property constraints: Considering the thermal expansion coefficient, yield strength, and hot cracking tendency of aluminum alloys, excessively slender columns and large-span thin-walled structures are limited. Support structure requirements constraints: Areas with a sag angle greater than 45° require support or sag reduction through reconstruction. Interlayer adhesion constraints: Limit layer thickness and scanning spacing to avoid incomplete fusion and porosity between layers.

[0068] 2.1 Construction of Material Distribution Model Based on printing accuracy constraints, the preliminary topological model is subjected to geometric size screening. Small ribs, sharp corners and isolated thin-walled units with feature sizes less than 0.6 mm are marked as removable regions. Morphological opening operations and other methods are used to remove them or merge them with neighboring entities to eliminate detailed structures that the printing equipment cannot reliably form.

[0069] Based on the support structure requirements, overhanging regions are identified in the preliminary topological model. Using the Z-axis as a reference, the angle θ between the local normal and the horizontal direction is calculated on the 3D model surface. Regions with an angle less than 45° and located in an overhead position are marked as overhanging regions. For regions with an overhang length exceeding 3mm, reconstruction is performed using one of the following methods:

[0070] By adding inclined transition ribs, the original horizontal cantilever is adjusted to an inclined beam of about 45°. The local cross section is appropriately thickened, and a transition connection with the adjacent structure is established to shorten the cantilever length. Transition units are inserted into the internal lattice structure to improve the local support effect.

[0071] Based on material properties and interlayer adhesion, the internal spacing is adjusted through fusion. For pores or lattice elements formed after topology optimization, incomplete fusion defects are prone to occur when the spacing between adjacent elements is less than 0.4 mm; deformation and cracks are prone to occur when the spacing is greater than 2.0 mm and located in a high-temperature gradient region. The spacing of internal pores or mesh elements is limited to the range of 0.5 mm-1.8 mm. Spacing exceeding this range is adjusted through scaling element size, merging, or splitting elements to obtain a continuous and printable internal material distribution. Through three sub-steps—minimum feature size elimination, overhang region reconstruction, and spacing fusion—a material distribution model that meets additive manufacturing constraints is formed.

[0072] 2.2 Printing Path Planning and Additive Manufacturing Optimization Model Formation Printing path planning was performed based on the material distribution model. Layer thickness parameters were determined according to specific manufacturing constraints, with 0.04 mm selected as an intermediate value. While meeting surface accuracy and forming efficiency requirements, the material distribution model was discretized into several printing layers along the Z-direction. For an inertial navigation system with a total height of 55 mm, approximately 1375 layers were generated.

[0073] For each printed layer, extract the outline and generate the fill trajectory: The contour scanning path uses a single outer contour plus a single inner contour, and the angle between the contour scanning line and the layer plane is 0°.

[0074] The filled area employs a 45° / 135° cross-scan strategy, with alternating scan angles between adjacent layers to reduce residual stress accumulation.

[0075] The scanning spacing of the filling trajectory is set to 0.10mm-0.12mm based on interlayer adhesion and linear energy density constraints.

[0076] Generate corresponding scan path codes, which record the motion trajectory, on / off state, and contour sequence of the laser spot in each printing layer. Perform process parameter matching on the scan path codes.

[0077] For path segments requiring high stress or high stiffness, a higher linear energy density is applied. For thin-walled, fine-structured areas, a lower energy density is applied to reduce thermal deformation. For path segments close to the support structure, the scanning speed is appropriately reduced by 5%-10% to improve the fusion quality between the support and the main body.

[0078] Example 3 This embodiment generates a lightweight porous support structure by performing spatial geometry determination of the suspended area of ​​the optimized inertial navigation system platform structure, and adopts an additive manufacturing printing strategy by combining fixed layer thickness equal-thickness slicing with partitioned process parameter matching.

[0079] 1. Spatial geometry determination of the support area and generation of the support structure In the 3D model of the inertial navigation system platform, the surface of the outer surface and the internal biomimetic lattice unit are scanned face by face with the Z-axis as the construction direction. The angle θ between the normal vector of each triangular facet and the horizontal direction is obtained through geometric calculation. When θ is less than 45° and the region is located in an upper suspended position and there is no formed solid support below within a certain height, the region is marked as the suspended structure region that needs to be supported.

[0080] Taking a certain optimized inertial navigation system (INS) platform as an example, its overall dimensions are approximately 220mm × 180mm × 55mm. The optimized internal structure employs a combination of biomimetic lattice and variable-density filling. Specifically:

[0081] A biomimetic lattice network is arranged on the mounting surface and surrounding areas where high rigidity is required. The element side length is approximately 3.0 mm, and the cross-sectional dimension at the node is approximately 1.2 mm. The central weight-reduction zone uses a variable-density infill material, with the infill density distributed between 35% and 55%. A porous support frame is arranged near the mounting holes and edge transition areas, with the hole diameter ranging from 1.5 mm to 2.5 mm.

[0082] In terms of construction direction, there are several large-area overhanging structures in an area of ​​approximately 12mm-28mm above the base plate of the platform. Among them, the angle between the local lattice beams and the horizontal plane is approximately 20°-30°. Without support, these structures are prone to sagging or breaking during printing. The total area of ​​the overhanging surfaces requiring support is approximately 3800mm², accounting for about 22% of the total exposed surface area.

[0083] For the overhanging structure area, a combination of skeleton support and locally denser dot matrix is ​​used to generate the support structure: Skeleton support generation: Using the outline of the overhanging area projected onto the substrate plane as the boundary, support column nodes are arranged within the area at a grid spacing of 5mm×5mm.

[0084] The support column has a diameter of 1.2 mm and a maximum height of approximately 18 mm. The top is connected to the cantilever surface by a 0.6 mm thick transition platform to reduce stress concentration.

[0085] The support columns are connected by thin crossbeams every 8-10 mm along the height direction. The crossbeams are about 0.8 mm thick, forming a porous support frame to improve the overall stability of the support.

[0086] Local dot matrix encryption: For the biomimetic lattice structure located beneath the overhanging area, the original unit side length was locally reduced from 3.0 mm to 2.0 mm, and the lattice beam thickness was increased from 1.2 mm to 1.5 mm, enabling the biomimetic lattice structure to function as both a structure and a support during the printing process. After adjustments, the relative density of the area increased from approximately 40% to approximately 55%. Through the support generation strategy, the total volume of the resulting support structure is approximately 105 cm³, accounting for approximately 11% of the optimized main structure volume.

[0087] 2. Equal thickness printing and printing strategy formation A fixed layer thickness of 0.08mm was selected as the only increment for the support structure, which can ensure the forming accuracy of the area where the support and the main body are combined without excessively reducing the processing efficiency.

[0088] With Z=0 as the printing substrate plane and the highest point of the support structure approximately Z=30mm, the slicing process of the support structure is as follows: Number and order of slices: With a fixed layer thickness of 0.08 mm, slices were made layer by layer from Z=0 upwards until Z=30 mm.

[0089] Approximately 375 support slice layers were generated, with the slicing sequence performed from the printed substrate to the top of the printed substrate to ensure that the support was formed layer by layer from bottom to top.

[0090] In-layer scanning strategy: The outer contour of the support column and beam is scanned in each layer. The contour scanning adopts a single contour plus a compensation contour, with a contour line spacing of 0.10mm. For the internal filling area of ​​the porous support skeleton, an alternating 45° and 135° oblique filling method is used. The scanning angle of adjacent layers is changed alternately to reduce residual stress. The scanning path near the support column is planned in the order from the inside to the outside to reduce local heat accumulation.

[0091] Process parameter matching: The laser power in the support structure area is selected to be 260W-280W, and the scanning speed is about 1000mm / s to ensure the rigidity of the support and avoid overheating.

[0092] Within the transitional small platform layer where the support contacts the main body, the scanning speed is reduced by approximately 10% compared to the support area, and the scanning spacing is decreased to enhance the interlayer fusion quality between the support and the main body.

[0093] For slender support columns with a height exceeding 20mm, an additional ring-shaped auxiliary track is added at 2-3 key height levels to improve the overall resistance to deformation.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for designing a lightweight additive manufacturing topology inertial navigation system platform model, characterized in that, include: S1. Obtain the mechanical performance requirements and dimensional parameters of the target component through sensors, and construct a preliminary topological structure model based on the mechanical performance requirements and dimensional parameters; S2. Obtain specific manufacturing constraints in the additive manufacturing process by pre-setting manufacturing parameters, preprocess the preliminary topology model based on the specific manufacturing constraints, and form an additive manufacturing optimization model through the preprocessing. S3. Based on the specific manufacturing constraints, the additive manufacturing optimization model is topologically optimized to obtain a lightweight topology. The topology optimization includes particle swarm optimization algorithm and simulated annealing method. S4. Perform spatial geometry determination on the support region of the lightweight topology, and generate a support structure through the spatial geometry determination; S5. Based on the specific manufacturing constraints, the support structure is printed with equal thickness, and the final printing strategy is formed through the equal thickness printing.

2. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 1, characterized in that: The mechanical performance requirements data include stress and strain, and the dimensional parameter data includes the component geometry and component thickness. The construction uses stress and strain as material distribution rules and the component geometry and component thickness as geometry control rules.

3. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 1, characterized in that: The specific manufacturing constraints include printing accuracy, material properties, support structure requirements, and interlayer adhesion.

4. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 3, characterized in that: The preprocessing includes the following steps: S21. Based on the printing accuracy, the minimum feature size of the preliminary topology model is eliminated; based on the support structure requirements, the overhanging area of ​​the preliminary topology model is reconstructed; based on the material properties and interlayer adhesion, the spacing of the preliminary topology model is fused; and a material distribution model is formed through the elimination, overhanging area reconstruction and fusion. S22. Perform printing path planning on the material distribution model. The printing path planning discretizes the material distribution model into printing layers according to the specific manufacturing constraints, plans the movement trajectory of the printing layers, generates scanning path codes based on the planning, and performs process parameter matching on the scanning path codes to form an additive manufacturing optimization model.

5. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 1, characterized in that: The particle swarm optimization algorithm performs global iterative optimization on the additive manufacturing optimization model. The global iterative optimization aims to minimize the amount of material used. The global iterative optimization simulates the random motion and group cooperation of particles in the solution space based on specific manufacturing constraints. The additive manufacturing optimization model is iterated based on the simulation process, and an optimized topology model is formed through the iteration.

6. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 5, characterized in that: The simulated annealing method fine-tunes the optimized topology model, forming a locally optimized topology. Geometric smoothing is then applied to this locally optimized topology to create a lightweight topology. The geometric smoothing rounds the sharp interior corners of the locally optimized topology, with the minimum radius of curvature set between 0.15 mm and 0.3 mm. The fine-tuning includes the following steps: S31. The optimized topology model is subjected to region identification to form characteristic structural regions, which include high-load regions, stress concentration regions and unstable regions; S32. The high-load area is structurally reinforced, the structural reinforcement involves increasing the material density of the high-load area, and a reinforced structural area is formed based on the material density. The stress concentration area is stress-buffered to form a stress-buffered area. The stress-buffered area uses a gradient material transition. Local support ribs are provided to the unstable area to form a stable topological area. S33. Integrate the reinforced structural region, stress buffer region, and stable topology region to form a lightweight topology.

7. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 1, characterized in that: The lightweight topology includes a biomimetic lattice network, a variable-density filler, and a porous support framework.

8. The method for designing a lightweight additive manufacturing topology inertial navigation system platform model according to claim 1, characterized in that: The spatial geometry determination extracts the angle between the surface of the support area and the horizontal direction. When the angle is less than 45 degrees, the support area is determined to be a suspended structure area, and a support structure is generated based on the suspended structure area.

9. The additive manufacturing method for lightweight topology inertial navigation system platform model design according to claim 1, characterized in that: The uniform thickness printing uses a fixed layer thickness as the only increment, and the support structure is sliced ​​based on this unique increment. The slicing order is from the printed substrate to the printed top, and the fixed layer thickness ranges from 0.05 mm to 0.2 mm.

10. A design system for a lightweight additive manufacturing topology inertial navigation system platform model, characterized in that: Topology construction module: used to acquire mechanical performance requirements and dimensional parameters of the target component through sensors, and to construct a preliminary topology model based on the mechanical performance requirements and dimensional parameters. Manufacturing constraint preprocessing module: used to obtain specific manufacturing constraints in the additive manufacturing process through preset manufacturing parameters, preprocess the preliminary topology model based on the specific manufacturing constraints, and form an additive manufacturing optimization model through the preprocessing. Topology optimization solution module: used to perform topology optimization on the additive manufacturing optimization model, and generate a lightweight topology based on the topology optimization. The topology optimization is based on the specific manufacturing constraints and includes particle swarm optimization algorithm and simulated annealing method. Support structure generation module: used to perform spatial geometry determination on the support region of the lightweight topology, and generate the support structure through the spatial geometry determination; Printing strategy planning module: used to perform equal-thickness printing on the support structure, and to form a final printing strategy through equal-thickness printing, which is based on the specific manufacturing constraints.

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