Fast force verification system to replace CAE simulation

Abstract

This invention relates to the field of automotive component design verification and mechanical structure analysis technology, specifically to a rapid mechanical verification system that replaces CAE simulation. This system includes a tolerance limit verification module, a contact point trajectory tracking module, and a motion interference verification module. It calculates the mechanical limit range and evaluates design robustness under tolerance coupling through analytical mechanical models and extreme value methods. It solves the mechanical response problem throughout the assembly stroke by tracking the contact point trajectory using geometric analysis. Based on rigid body kinematics and envelope geometry, it calculates motion clearances and determines interference risks. Each module can link and call tolerance boundary data, integrating and outputting verification results. Without mesh generation and nonlinear iteration, it can quickly complete multi-dimensional structural performance verification, adapting to rapid scheme selection in the early design stage and improving design and development efficiency.

Description

Technical Field

[0001] This invention relates to the field of automotive component design verification and mechanical structure analysis technology, and more specifically, to a rapid force verification system that replaces CAE simulation. Background Technology

[0002] This invention belongs to the field of automotive component design verification and mechanical structure analysis technology. It is widely used in the entire process of design and development of automotive interior switches and snap-fit ​​assembly structures, and is a core technology link to ensure product structural strength, assembly performance and motion safety.

[0003] In existing technologies, CAE finite element simulation technology is the mainstream method for verifying the mechanics, assembly, and motion interference of mechanical structures. While this technology can achieve high-precision simulation analysis, it has several shortcomings that make it difficult to adapt to the needs of early-stage design development: First, CAE simulation requires complex geometric cleanup, mesh generation, contact pair setup, and nonlinear iterative calculations, resulting in a long verification cycle for a single scheme and making it impossible to support the rapid selection and iterative optimization of a large number of schemes in the early stages of design. Second, existing verification schemes are mostly based on the nominal dimensions of the structure, making the coupled analysis of manufacturing tolerances and assembly tolerances difficult and cumbersome. This makes it difficult to fully cover extreme working conditions with multiple coupled parameters, and it is easy to encounter problems such as simulations passing in the design stage, but large fluctuations in product performance and high failure risks after mass production. Third, the verification of structural strength, assembly performance, and motion interference requires the establishment of different simulation models step by step, resulting in poor data linkage and an inability to achieve integrated and rapid verification of multi-dimensional performance, which has a high technical threshold and development cost.

[0004] To overcome the aforementioned shortcomings of existing technologies, this invention proposes a rapid force verification system that replaces CAE simulation. Summary of the Invention

[0005] In view of the shortcomings of existing technologies, the purpose of this invention is to provide a rapid force verification system that can replace CAE simulation.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A rapid force verification system that replaces CAE simulation includes a tolerance limit verification module, a contact point trajectory tracking module, and a motion interference verification module; The tolerance limit verification module is used to receive the geometric parameters, dimensional tolerance zones and material property parameters of the structure to be verified, establish a mechanical analytical model of the corresponding structure, identify key dimensional parameters that have a significant impact on the mechanical response, calculate the mechanical response limit range under the most unfavorable tolerance combination of multi-parameter coupling by the extreme value method, and output the design robustness evaluation parameters and limit tolerance boundary data of the structure to be verified. The contact point trajectory tracking module is used to receive the mating geometric parameters of the assembly structure to be checked, track the real-time movement trajectory of the contact points during the assembly process through geometric analysis methods, calculate the time-varying effective lever arm based on the change of contact point position, and generate mechanical response data for the entire assembly stroke by combining material performance parameters and friction characteristics of mating surfaces. The motion interference verification module is used to receive the kinematic parameters of the moving part to be verified and the geometric parameters of the surrounding related parts, establish a rigid body kinematic model, extract the key positions of the entire motion stroke, generate envelope geometric features covering the entire motion stroke, and complete the minimum gap calculation and interference risk judgment during the motion process through analytical geometry methods; the modules can realize the transfer and linkage of tolerance boundary data, and integrate and output the verification results.

[0007] Furthermore, the tolerance limit verification module first calculates the sensitivity of each dimensional parameter to the mechanical response using the single-factor variable method, filters out the key dimensional parameters whose sensitivity exceeds the preset threshold, then defines the tolerance zone range corresponding to each key dimension, obtains the full-parameter function expression of the mechanical response with respect to each key parameter by combining the mechanical analytical model, clarifies the influence trend of each parameter on the mechanical response through single-factor analysis, determines the most unfavorable tolerance combination that can occur simultaneously based on the extreme value method, solves the limit interval of the mechanical response, and then calculates the robustness evaluation parameters based on the allowable performance parameters of the material.

[0008] Furthermore, the tolerance limit verification module simultaneously introduces the tolerance zone of the fit interference during the determination of the most unfavorable tolerance combination, incorporates the fit interference into the full parameter function expression, and simultaneously analyzes the influence trend of the interference tolerance on the mechanical response, completing the coupled analysis with the dimensional tolerance, and covering the mechanical response boundary under all possible extreme working conditions.

[0009] Furthermore, the contact point trajectory tracking module first establishes a contact geometry model of the assembly mating structure, calculates the real-time position of the contact point under different assembly displacements based on the correspondence between assembly displacement and contact geometry, then solves the effective lever arm that changes in real time with the assembly displacement based on the contact point position, calculates the time-varying normal stiffness based on the effective lever arm, and finally solves the assembly force by combining the normal displacement and friction characteristics.

[0010] Furthermore, the contact point trajectory tracking module calls the dimensional tolerance zone, angular tolerance zone, and friction coefficient fluctuation range output by the tolerance limit verification module, and uses the extreme value method to calculate the extreme value range of assembly mechanical response under different tolerance combinations, thereby completing the robustness assessment of assembly performance.

[0011] Furthermore, the contact point trajectory tracking module discretizes the amount of insertion during the entire assembly stroke into multiple equally spaced calculation points, solves the corresponding effective lever arm and assembly force at each calculation point, generates a continuous assembly force-displacement curve for the entire assembly stroke based on the discrete calculation results, and simultaneously outputs the curve peak value and characteristic parameters.

[0012] Furthermore, the motion interference verification module first completes the sampling of key positions throughout the motion stroke based on the rigid body kinematic model of the component to be verified, then extracts the discrete point set of the outer contour of the component to be verified, calculates the coordinate transformation results of the point set at each sampling position, generates an envelope geometric feature covering the motion boundary based on the point set of the entire stroke, and calculates the minimum distance between the envelope geometric feature and the simplified geometric elements of the surrounding parts through analytical geometric formulas.

[0013] Furthermore, during the minimum gap calculation process, the motion interference verification module simultaneously introduces the dimensional tolerances and assembly position tolerances of the component to be verified and the surrounding parts, converts the tolerances into the offset range of geometric parameters, takes the tolerance limit offset along the gap reduction direction, and calculates the minimum gap extreme value under the influence of the tolerance through the extreme value method to complete the interference risk judgment.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention establishes a structural mechanics analytical model through a tolerance limit verification module. Combining single-factor variable sensitivity screening with a multi-parameter coupled extreme value method, it achieves a linked analysis of manufacturing tolerances and mechanical performance. This module can accurately identify key dimensional parameters that significantly affect mechanical response. It solves the limit ranges of stiffness, load, and stress using the extreme value method, synchronously coupling and coordinating interference tolerance bands to cover the mechanical response boundaries under all extreme working conditions, ultimately outputting robustness evaluation parameters for structural design. This technical solution eliminates the need for complex model processing and iterative calculations, rapidly quantifying performance fluctuations caused by manufacturing tolerances. It solves the problems of poor mass production performance consistency and high failure risk caused by traditional verification neglecting the influence of tolerances, providing a quantitative basis for optimizing structural dimensions and tolerance design. 2. This invention achieves integrated and rapid verification of assembly performance and motion safety through the collaboration of a contact point trajectory tracking module and a motion interference verification module, combined with cross-module linkage of tolerance data. The contact point trajectory tracking module tracks the real-time motion trajectory of the contact point using geometric analytical methods, solves for the time-varying effective lever arm and the mechanical response throughout the assembly stroke, and can simultaneously complete the robustness assessment of assembly performance under the influence of tolerances. The motion interference verification module generates full-stroke envelope geometric features based on a rigid body kinematic model, and integrates tolerance limits to complete minimum clearance calculation and interference risk assessment. Both modules employ analytical algorithms, avoiding the complex contact iteration and multi-condition step-by-step modeling required in CAE simulation, significantly reducing the technical threshold and time cost of verification, and enabling simultaneous quantitative assessment of structural assembly feel, assembly difficulty, and motion interference risk. Attached Figure Description

[0015] Figure 1 Module block diagram of a rapid force verification system to replace CAE simulation; Figure 2 This is a flowchart illustrating the implementation of the tolerance limit verification module of the present invention. Figure 3 This is a flowchart illustrating the implementation of the contact point trajectory tracking module of the present invention. Detailed Implementation

[0016] Example, refer to Figure 1 The rapid force verification system in this embodiment, which is an alternative to CAE simulation, includes a tolerance limit verification module, a contact point trajectory tracking module, and a motion interference verification module. M1, Tolerance Limit Verification Module: This module couples the dimensional tolerance zone with the mechanical analytical model. It calculates the stress and deformation range under the most unfavorable tolerance combination using the extreme value method, thereby outputting a robustness score for the design scheme. This solves the problem of inconsistent design quality and post-manufacturing feel caused by neglecting manufacturing tolerances in traditional mechanical calculations. For example... Figure 2 As shown, the specific implementation steps are as follows: S1. Establish a mechanical analytical model: For a typical structure in a car switch handle, the cantilever buckle, the bending stress at its root... This can be expressed based on cantilever beam theory as follows: ; Where F is the release force acting on the end of the buckle, the value of which is based on the cooperation interference of the buckle locking structure and the stiffness of the buckle arm, and the dimension is N; L is the lever arm length, that is, the distance from the root to the point of force application, and the dimension is m; b is the buckle arm width, and the dimension is m; h is the buckle arm thickness, and the dimension is m. This formula applies to rectangular cantilever beams with uniform cross-sections. When the cross-section is not rectangular, a section modulus can be introduced for correction. The corrected formula is as follows: ; Where W is the section modulus for bending resistance, its value is determined based on the geometry of the section and can be calculated using the formula for calculating the geometric parameters of a section in mechanics of materials, and its dimension is... For example, the W value can be calculated for circular cross-sections and trapezoidal cross-sections using the corresponding formulas, and the basic calculation logic of the formulas remains unchanged; This embodiment uses the most common bending failure mode of snap fasteners as the core of the verification. If shear failure needs to be verified, analytical calculation of shear stress and tolerance coupling analysis can be added simultaneously. The formula for calculating shear stress is: ; The meaning of the formula parameters is the same as described above. The same extreme value method as in the extreme condition combination calculation of this module can be used, that is, select the most unfavorable tolerance combination of the key dimensions (b, h, F) that affect the mechanical response, substitute them into the shear stress formula to calculate the ultimate shear stress range, and then complete the robustness assessment under the shear failure mode. S2. Define dimensional tolerance zones: Identify key dimensional parameters that influence mechanical response. Identification is based on dimensional parameters whose sensitivity to bending stress and stiffness calculations exceeds a preset threshold. Sensitivity can be calculated using the single-factor variable method, i.e., the ratio of stress change to a single unit change in a dimension. Key dimensional parameters typically include the latch arm length L, thickness h, width b, and mating dimensions of the parts, such as the slot depth and lead-in angle. Let the nominal values ​​and tolerances of each dimension be as follows: The tolerance zone can be preset according to the manufacturing process. The selection criteria are the molding shrinkage rate of the injection molding material, the processing accuracy of the mold, and the process stability of mass production. For example, for ABS and PC, which are commonly used injection molding materials for automotive interiors, when the molding size is less than 50mm, it is recommended to use IT8~IT12 tolerance. IT10 tolerance is suitable for conventional snap-fit ​​structures with medium precision requirements. S3. Limit Condition Combination Calculation: Based on the fundamental theory of mechanics of materials, the calculation formulas for bending stress, cantilever beam stiffness, and pull-out force are combined to obtain a complete functional expression of stress with respect to each design parameter and tolerance zone. The influence trend of each parameter on stress is clarified, and the extreme value method is used to determine the most unfavorable tolerance combination that can occur simultaneously and cause the bending stress to reach its extreme value. The specific implementation steps are as follows: The first step is to solve the simultaneous equations to clarify the total parametric function relationship of stress: Formula for the stiffness of the buckle arm , Ejection force formula Substituting into the bending stress formula and simplifying, we obtain the fully parametric expression for the stress: ; In the formula, E is the elastic modulus of the material (a material property parameter, tolerance fluctuations are negligible), and h is the thickness of the buckle arm. The amount of interference between the buckle and the counter part, where L is the length of the buckle arm and b is the width of the buckle arm; The second step is single-factor sensitivity analysis to determine the influence trend of each parameter on stress: By using the single-factor variable method, the fluctuations of each key dimensional parameter and interference parameter were clarified, and the stress was analyzed. The direction of influence provides a quantitative basis for determining the most unfavorable tolerance combination: Buckle arm length L: L and When the correlation is negative, and L takes the lower limit (minimum) of the tolerance, Increase; when L takes the upper limit (maximum value) of the tolerance, Decrease; Buckle arm thickness h: h and When they are positively correlated, and h takes the upper limit (maximum value) of the tolerance, Increase; when h takes the lower limit (minimum) of the tolerance, Decrease; Coordination Interference : and Positive correlation, When taking the upper limit (maximum value) of the tolerance, Increase; When taking the lower limit (minimum value) of the tolerance, Decrease; The width b of the buckle arm: After simplifying the equations, b cancels out in both the numerator and denominator, thus affecting the stress. It has no direct impact, but only affects the stiffness and shear stress of the buckle arm; The third step is to determine the most unfavorable tolerance combination using the extreme value method and calculate the stress limit range: Based on the above-mentioned influence trends, the bending stress is determined to be... The most unfavorable tolerance combination that reaches the maximum value is: h is taken as the upper limit of the tolerance. , Take the upper limit of the tolerance L is taken as the lower limit of tolerance. ; Determine the bending stress The most favorable tolerance combination to achieve the minimum value is: h is taken as the lower limit of the tolerance. , Take the lower limit of tolerance L is taken as the upper limit of tolerance. ; Substituting the two sets of tolerance combinations into the stress full parameter expression, the stress limit range is calculated: Maximum stress: ; Minimum stress: ; For other failure modes such as shear failure, torsion failure, and contact stress failure, the above unified logic is adopted: combining full-parameter function expressions → analyzing the influence trend of parameters by single factors → determining the most unfavorable tolerance combination that can occur simultaneously → calculating the extreme value range. This ensures that the extreme value calculation conforms to the actual engineering situation and fully covers real extreme working conditions. By default, it is assumed that each tolerance item is independent and can reach its tolerance limit simultaneously to obtain a conservative worst-case boundary. When there are dimensional chains, assembly constraints, or process dependencies that prevent tolerance items from reaching their limits independently, the constraints can be represented as feasible regions (e.g., linear / nonlinear inequality constraints), and extreme value search can be performed on the target response within the feasible region to obtain the worst-case tolerance combination that satisfies the engineering constraints. S4. Robustness Score: The calculated stress range With the allowable stress of the material In comparison, the robustness score R is defined as follows: ; Among them, allowable stress of materials The value is based on the yield strength of the material divided by the safety factor. The safety factor is determined according to the safety level of the product. The conventional safety factor for automotive interior parts is 1.5 to 3, which can be calculated by obtaining the yield strength of the corresponding material from the material performance manual. The dimension is Pa. The robustness evaluation criteria are as follows: like If the design scheme is deemed robust enough, even under the most unfavorable combination of manufacturing and assembly tolerances, the structural stress still meets the allowable material requirements, and there is no risk of plastic deformation or fracture failure. like If the design scheme is not robust enough, it is necessary to optimize the nominal value of the dimensions, tighten the tolerance zone, or adjust the structural design to improve safety redundancy. like If the design scheme is determined to have a maximum structural stress exceeding the material's allowable stress under extreme tolerance combinations, it is considered to have an extremely high risk of failure and requires immediate design optimization. The above scoring thresholds are determined based on industry design specifications and safety redundancy requirements for automotive switch handles. They can be adjusted according to the product's usage scenario and safety level. For example, for high-security door lock latch structures, the pass threshold can be increased by 20% to 30%. M2, Contact Point Trajectory Tracking Module: This module addresses the time-varying lever arm effect caused by the sliding of contact points along the inclined plane during snap-fit ​​assembly. It tracks the contact point trajectory using geometric analytical methods and calculates the effective lever arm segment by segment, ultimately generating a force-displacement curve for the entire assembly process. This enables quantitative prediction of assembly feel and peak force. This module avoids the complex contact iterations found in CAE, maintaining the advantage of rapid calculation. Figure 3 As shown, the specific implementation steps are as follows: S1. Contact geometry modeling: Taking a typical snap-fit ​​structure as an example, the snap-fit ​​end has an inclined surface, and the angle between the inclined surface and the horizontal direction is... The dimension is rad; the hand component, such as the slot, is a fixed rigid body; assume that the displacement of the buckle during assembly is y along the vertical direction, i.e., the snapping direction, and define the initial contact time as... The initial contact state refers to the position where the snap-fit ​​guide slope first contacts the edge of the counterslip groove. At this point, the snap-fit ​​has not undergone elastic deformation, and the reference zero point of the snap-fit ​​amount y is determined based on this state. According to geometric relationships, the position s of the contact point on the slope, i.e., the distance along the slope from the starting point, is related to the snap-fit ​​amount y as follows: ; This formula assumes that the change in the inclined plane angle caused by the deformation of the buckle is negligible and is applicable to small deformation ranges. The criteria for determining small deformation ranges are: the maximum bending deformation of the buckle arm is less than 5% of the total length of the cantilever beam. At this time, the change in the inclined plane angle is less than 1°, and its influence on the calculation of the contact point position can be ignored. If the deformation exceeds the small deformation range, the contact point position can be corrected by iterative method. That is, first calculate the contact point position and deformation through the initial geometric relationship, then correct the angle and position of the inclined plane according to the deformation, recalculate the contact point, and iterate until the calculation result converges. The convergence threshold can be set to the deformation change being less than 0.01mm. S2. Calculation of the effective lever arm: The change in the position of the contact point leads to the change in the effective lever arm. Change; Assume the root of the buckle arm is the fixed end, and the horizontal distance from the starting point of the inclined plane to the root is... , In the undeformed state, the horizontal projection distance of the starting end of the latch guide ramp relative to the fixed end of the latch arm root can be obtained by directly measuring the difference in horizontal coordinates of two feature points in the latch movement plane using the 3D digital model of the switch handle; the dimension is m. Therefore, the horizontal distance from the contact point to the root, i.e., the effective lever arm, is: ; It can be seen that the lever arm increases linearly with the amount of latching y; S3. Stiffness and Assembly Force Calculation: Normal stiffness of the buckle arm at the contact point The normal force required to generate a unit normal displacement can be calculated using cantilever beam theory. Due to the change in lever arm, the stiffness also varies with y. For a small segment, the buckle can be considered a cantilever beam with a variable lever arm, and its normal stiffness is approximately: ; This formula is derived from the deflection formula of a cantilever beam subjected to a concentrated normal force at its end. The deflection formula for a cantilever beam is: Where I is the moment of inertia of the cross section, for a rectangular cross section After substituting into the deflection formula, the stiffness definition is applied. The above formula is derived and is applicable to scenarios with small deformation where the normal displacement at the contact point is much smaller than the length of the latch arm. Where E is the elastic modulus of the material, and b and h are the width and thickness of the latch arm, which are assumed to be of uniform cross-section. The meaning of the parameters is consistent with that of the tolerance limit check module. For a variable cross-section latch arm, it can be divided into uniform cross-section micro-segments along the length of the latch arm. The equivalent bending stiffness at the corresponding contact point position can be calculated by integral method, and the stiffness term in the original formula can be replaced.

[0017] During the actual snap-fit ​​process, the normal displacement at the contact point The relationship with the deduction amount y is as follows Because the snapping direction is perpendicular, the normal component is The dimension is m; therefore, the normal reaction force at the contact point is: ; Assembly force That is, the force required to be applied along the snapping direction consists of the perpendicular component of the normal force and the frictional force; the frictional force is along the inclined plane and its magnitude is... ,in The coefficient of friction is determined by the type of mating materials, surface roughness, and lubrication condition. It can be selected from material friction performance test manuals or industry-standard empirical values. For example, ABS-PC is typically taken as 0.3~0.4 against steel, and it has no unit. The equilibrium equation in the vertical direction is: ; Will Substituting, we get: ; This module can be linked with the tolerance limit verification module to calculate the dimensional tolerance zone, including the maximum and minimum peak assembly forces under different tolerance combinations, thus achieving robust evaluation of assembly forces. Specifically, it calculates the extreme value range of assembly forces under different tolerance combinations. , angle tolerance Friction coefficient fluctuation range Substituting into the assembly force formula, the extreme value method is used for calculation. The maximum and minimum values ​​cover the fluctuations in assembly feel caused by manufacturing tolerances; S4. Piecewise solution and curve generation: The offset y is calculated from 0 to the maximum interference. That is, the interference amount when the buckle is fully engaged, discretized into N equally spaced points, in this embodiment. The value of N can be adjusted according to the required calculation accuracy. It is recommended to use 50~200 in the conventional conceptual design stage. The larger the value of N, the higher the calculation accuracy, and the corresponding calculation time will increase slightly. The total displacement along the latching direction when the latch moves from the initial contact position to the fully engaged and locked position can be measured by the relative position of the latch and the locking mechanism of the other part in the three-dimensional digital model, and the dimension is m; At each discrete point Calculation and A series of points were obtained. Connecting these points sequentially yields the assembly force-displacement curve; the peak value of the curve... This refers to the maximum assembly force, which can be used to assess the ease of assembly. The peak assembly force for conventional automotive switch handles is recommended to be controlled within the range of 30N~80N. The shape of the curve, such as the force rise rate, can reflect the assembly feel. It can be quantitatively evaluated by parameters such as the slope change rate of the assembly force-displacement curve, the location of the peak force, and the force drop after the engagement is complete. A uniform force rise rate without abrupt changes indicates a good feel. The module outputs the peak force and complete curve data.

[0018] M3, Motion Interference Verification Module: This module is used to detect whether the gap between the handle and surrounding parts (such as the base, wiring harness, and interior panels) meets safety requirements during the opening process. Based on the concept of envelope surfaces and geometric analytical methods, it extracts the envelope lines / surfaces at key locations and integrates tolerance analysis to assess the interference risk under the worst-case assembly condition. The specific implementation steps are as follows: S1. Key Position Extraction: Based on the kinematic model of the handle, such as rotation around a fixed axis or planar motion, select three key positions during the opening process: initial closed position, intermediate position (e.g., open 30°), and extreme open position. The selection of key positions is based on covering the entire stroke of the handle. The initial closed position and extreme open position are the two endpoints of the stroke. The intermediate position is selected as the midpoint of the stroke or a commonly used opening angle position, which can cover the motion boundary of the maximum outer contour. These positions can be calculated from the handle rotation center, arm length, and maximum opening angle. For a handle that rotates about a fixed axis, the kinematic model is established by extracting the spatial vector of the rotation axis from a three-dimensional digital model. The coordinates of the rotation center and the maximum rotation angle range of the handle are used to establish a rigid body kinematic model of the handle. The motion trajectory of any point on the handle can be calculated by the rigid body rotation matrix. For complex spatial motion, a uniform sampling method can be used to select M corner positions, such as taking one position every 10°. The sampling interval is determined based on the handle outline size and the minimum clearance requirements of surrounding parts. A sampling interval of 5°~15° is recommended. The higher the clearance requirement, the smaller the sampling interval should be to ensure that no interference risk positions are missed. S2. Envelope Surface Generation: Based on the 3D digital model of the handle, extract the key point set of its outer contour to generate a simplified envelope polyhedron. The specific method is as follows: Discrete sampling is performed on the surface of the handle to obtain a point cloud. The sampling method is as follows: the outer contour surface of the handle is sampled according to the equal arc length or equal spacing. The sampling point density can be adjusted according to the complexity of the contour. For conventional curved surfaces, the recommended sampling point spacing is 0.5mm~2mm to ensure that no contour features are missed. Then, the new coordinates of these points after rotating around the motion axis at each key position are calculated. The convex hull of all position point clouds is taken as the envelope surface. The convex hull calculation can be performed using a three-dimensional convex hull generation algorithm (such as the QuickHull algorithm) to obtain the minimum envelope polyhedron covering the entire motion stroke of the handle. To reduce the amount of computation, only the contour feature lines can be extracted to generate a two-dimensional envelope polygon. This is suitable for scenarios where the handle motion is planar. Specifically, the outer contour feature lines of the handle in the motion plane are extracted, the envelope lines of the feature lines in the entire motion stroke are calculated, and a two-dimensional envelope polygon is generated, which greatly reduces the amount of computation. When using convex hull to generate envelope geometry features, this envelope is a conservative outer envelope of the swept volume, used for rapid screening of potential interference risks. To avoid missed detections due to only calculating distances to the envelope vertices, the minimum gap calculation can be based on a discrete set of points covering the envelope surface (point cloud density meets a preset upper limit for spacing), and the distances are calculated for analytical geometric elements such as point-plane, point-cylindrical, and point-sphere, taking the minimum value of the entire point set as the minimum gap for that pose. When it is necessary to reduce conservatism, the outer surface reconstruction of the union of multiple pose point sets can be used to approximate the true swept shape. S3, Minimum gap analytical calculation: In each At key locations, calculate the minimum distance between the handle's envelope surface and surrounding parts. The surrounding parts are also simplified to basic geometric elements, combinations of planes, cylinders, spheres, etc. The simplification criteria are: retain the feature surfaces adjacent to the handle's motion envelope surface, ignore distal structures that do not intersect with the handle's motion range, and simplify complex surfaces into standard geometric elements such as planes, cylinders, and spheres. The simplified geometric elements must completely cover the solid area of ​​the original parts to avoid overestimating the gap calculation results and overlooking interference risks. The minimum distance is solved using analytical geometric formulas, as follows: For example, any point on the handle envelope. The equation is related to the planes on the surrounding parts. : ; Where A, B, C, and D are the coefficients of the plane equation, determined by the geometric characteristics of the plane, and are dimensionless; d is the perpendicular distance from the point to the plane, with the dimension in meters. For a sphere, the equation of the sphere is: ,in Let R be the coordinates of the center of the sphere, R be the radius of the sphere (in meters), and let R be the coordinates of any point. The distance to the sphere is: ; For a cylindrical surface, the unit direction vector of the cylindrical surface axis is... The coordinates of any point on the axis are The cylindrical surface has a radius of R and a dimension of m. At any point... The perpendicular distance to the axis of the cylindrical surface is Then the distance from the point to the cylindrical surface is: ; Traverse all discrete points on the envelope surface, take the minimum value as the minimum gap at that position, and simultaneously record the point coordinates and surrounding part features corresponding to the minimum gap to facilitate subsequent positioning of the interference position; S4. Tolerance Sensitivity Analysis: Considering the tolerances of each part's dimensions and assembly position, such as the positional tolerance of the handle's rotation center and the positional tolerances of surrounding parts, each tolerance is converted into an offset range of geometric parameters. The minimum clearance is recalculated using the extreme value method. Specifically, for the positional tolerance of the handle's rotation center, the tolerance zone is converted into an offset range of the rotation center in three-dimensional space. The limit offset of the tolerance zone is taken along the direction that reduces the clearance between the handle's envelope surface and surrounding parts, and substituted into the kinematic model to calculate the limit position of the envelope surface. Similarly, for the positional tolerances of surrounding parts, the limit offset of the part's geometric elements is taken along the direction that reduces the clearance, and these are used in the minimum clearance calculation to finally obtain the minimum value of the clearance. ; like If the value is greater than the preset safety threshold (5mm in this embodiment), then there is no risk of interference; if If the threshold is reached, an early warning will be issued and specific interference coordinates will be provided; if If so, then interference is determined to exist; The safety threshold is determined based on the design specifications of automotive interior parts, taking into account manufacturing tolerances, assembly tolerances, and vibration displacement during vehicle operation. The recommended safety threshold for the gap around a standard automotive switch handle is 2mm to 5mm. For scenarios with wiring harnesses or soft interior materials, the threshold can be appropriately reduced.

[0019] In summary, the workflow of the system of the present invention is as follows: Step 1: Input the 3D digital model and material parameters of the switch handle, including the elastic modulus E and allowable stress. coefficient of friction Dimensional tolerance zones, i.e., the Δ values ​​of each critical dimension, and information on surrounding parts, including geometric shape and positional tolerances; Step 2: The tolerance limit check module calculates the nominal stress and limit stress range based on the input, outputs the robustness score R, and simultaneously outputs the limit tolerance boundary to the subsequent modules; Step 3: The contact point trajectory tracking module is based on snap-fit ​​geometry, including... Calculate the assembly force-displacement curve based on the tolerance boundaries of the call, and output the peak assembly force, the extreme range of the assembly force, and the complete curve data; Step 4: The motion interference verification module extracts the envelope surface of key positions, calculates the dynamic minimum gap, and after calling the tolerance boundary to consider the tolerance effect, outputs an interference risk report, including the gap value at each position and the coordinates of the worst gap position. Step 5: Integrate the outputs of each module to generate a rapid verification report of the design scheme, including whether it meets the requirements for strength, assemblability, and movement clearance, as well as robustness evaluation and optimization direction suggestions.

[0020] The tolerance boundary data includes at least: the nominal values, upper and lower limits, monotonicity information (increased / decreased / non-monotonic) of the key parameter set, and the most unfavorable combination vector obtained by the extreme value method (used to characterize the combination of upper / lower limits of each key parameter under extreme response); when the contact point trajectory tracking module and the motion interference verification module perform extreme value interval or minimum gap minimum value calculation, they read the same most unfavorable combination vector or reuse the same extreme value solution rule under the same constraint conditions, thereby realizing the consistency and linkage of tolerance boundary data in multi-performance verification.

[0021] All calculations employ analytical formulas and geometric algorithms, eliminating the need for mesh generation or nonlinear iterations. The verification time for individual solutions is significantly faster than traditional CAE simulations. This system complements CAE simulations, enabling rapid screening of numerous solutions in the early design phase. The selected high-risk or preferred options are then precisely verified using CAE, thereby significantly improving overall development efficiency.

[0022] Through the detailed description of the above embodiments, the rapid mechanical verification system of the present invention, which replaces CAE simulation, constructs an integrated rapid verification system covering structural strength robustness, assembly performance, and motion safety through the coordinated operation of tolerance limit verification module, contact point trajectory tracking module, and motion interference verification module. The system uses a material mechanics analytical model and analytical geometry algorithm as its core, abandoning the complex processes of mesh generation and nonlinear contact iteration required by traditional CAE simulation. Based on the input structural geometric parameters, tolerance zones, and material properties, it can quickly complete multi-parameter coupled limit condition analysis, assembly full-stroke mechanical response solution, and motion interference risk assessment. Simultaneously, the system realizes the linkage and transfer of tolerance boundary data between modules, ensuring that the entire verification process covers the extreme effects of manufacturing and assembly tolerances. The output verification results can comprehensively support the rapid evaluation and optimization of product design schemes, effectively adapting to the scenario of rapid screening of multiple schemes in the early stage of product design, improving design and development efficiency and mass production reliability.

[0023] The above formulas are all dimensionless calculations, and the preset parameters in the formulas should be set by those skilled in the art according to the actual situation.

[0024] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. A semiconductor medium can be a solid-state drive.

[0025] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0026] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0027] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0028] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0029] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0030] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A rapid force verification system that replaces CAE simulation, characterized in that, It includes a tolerance limit verification module, a contact point trajectory tracking module, and a motion interference verification module; The tolerance limit verification module is used to receive the geometric parameters, dimensional tolerance zones and material property parameters of the structure to be verified, establish a mechanical analytical model of the corresponding structure, identify key dimensional parameters that have a significant impact on the mechanical response, calculate the mechanical response limit range under the most unfavorable tolerance combination of multi-parameter coupling by the extreme value method, and output the design robustness evaluation parameters and limit tolerance boundary data of the structure to be verified. The contact point trajectory tracking module is used to receive the mating geometric parameters of the assembly structure to be checked, track the real-time movement trajectory of the contact points during the assembly process through geometric analysis methods, calculate the time-varying effective lever arm based on the change of contact point position, and generate mechanical response data for the entire assembly stroke by combining material performance parameters and friction characteristics of mating surfaces. The motion interference verification module is used to receive the kinematic parameters of the moving part to be verified and the geometric parameters of the surrounding related parts, establish a rigid body kinematic model, extract the key positions of the entire motion stroke, generate envelope geometric features covering the entire motion stroke, and complete the minimum gap calculation and interference risk judgment during the motion process through analytical geometry methods. The modules can transfer and link together to call tolerance boundary data, and integrate and output the verification results.

2. The rapid force verification system as an alternative to CAE simulation according to claim 1, characterized in that, The tolerance limit verification module first calculates the sensitivity of each dimensional parameter to the mechanical response using the single-factor variable method, screens out the key dimensional parameters whose sensitivity exceeds the preset threshold, defines the tolerance zone range corresponding to each key dimension, obtains the full-parameter function expression of the mechanical response with respect to each key parameter by combining the mechanical analytical model, clarifies the influence trend of each parameter on the mechanical response through single-factor analysis, determines the most unfavorable tolerance combination that can occur simultaneously based on the extreme value method, solves the limit interval of the mechanical response, and then calculates the robustness evaluation parameters based on the allowable performance parameters of the material.

3. The rapid force verification system for replacing CAE simulation according to claim 2, characterized in that, In the process of determining the most unfavorable tolerance combination, the tolerance limit verification module simultaneously introduces the tolerance zone of the fit interference, incorporates the fit interference into the full parameter function expression, and simultaneously analyzes the influence trend of the interference tolerance on the mechanical response. It completes the coupled analysis with the dimensional tolerance, covering the mechanical response boundary under all possible extreme working conditions.

4. The rapid force verification system as an alternative to CAE simulation according to claim 1, characterized in that, The contact point trajectory tracking module first establishes a contact geometry model of the assembly mating structure. Based on the correspondence between assembly displacement and contact geometry, it calculates the real-time position of the contact point under different assembly displacements. Then, based on the contact point position, it solves for the effective lever arm that changes in real time with the assembly displacement. Based on the effective lever arm, it calculates the time-varying normal stiffness. Finally, it combines the normal displacement and friction characteristics to complete the solution of the assembly force.

5. The rapid force verification system for replacing CAE simulation according to claim 4, characterized in that, The contact point trajectory tracking module calls the dimensional tolerance zone, angular tolerance zone and friction coefficient fluctuation range output by the tolerance limit verification module, and uses the extreme value method to calculate the extreme value range of assembly mechanical response under different tolerance combinations, thus completing the robustness assessment of assembly performance.

6. The rapid force verification system for replacing CAE simulation according to claim 4, characterized in that, The contact point trajectory tracking module discretizes the input amount of the entire assembly stroke into multiple equally spaced calculation points, solves the corresponding effective lever arm and assembly force at each calculation point, and generates a continuous assembly force-displacement curve for the entire assembly stroke based on the discrete calculation results, and outputs the curve peak value and characteristic parameters simultaneously.

7. The rapid force verification system for replacing CAE simulation according to claim 1, characterized in that, The motion interference verification module first completes the sampling of key positions throughout the motion stroke based on the rigid body kinematic model of the component to be verified, then extracts the discrete point set of the outer contour of the component to be verified, calculates the coordinate transformation results of the point set at each sampling position, generates an envelope geometric feature covering the motion boundary based on the point set of the entire stroke, and calculates the minimum distance between the envelope geometric feature and the simplified geometric elements of the surrounding parts through analytical geometric formulas.

8. The rapid force verification system for replacing CAE simulation according to claim 7, characterized in that, During the minimum clearance calculation process, the motion interference verification module simultaneously introduces the dimensional tolerances and assembly position tolerances of the component to be verified and surrounding parts, converts the tolerances into the offset range of geometric parameters, takes the tolerance limit offset along the clearance reduction direction, and calculates the minimum clearance extreme value under the influence of the tolerance through the extreme value method to complete the interference risk judgment.

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