A three-dimensional modeling system for a controller housing of a tailgate of an automobile

Abstract

The present application relates to the field of automobile electronics and three-dimensional modeling simulation technology, specifically to a kind of three-dimensional modeling system of automobile tail door controller shell, comprising: basic feature extraction module, initial shell parameter, shell material attribute and optical element three-dimensional size data are collected, and the coaxial constraint pair between light element installation groove and light return element installation groove is constructed;Stress field simulation module, extract the fitting gap, inject random floating vector, build solidification shrinkage connection element and calculate stress distribution and offset attitude data;Efficiency evaluation module, substitute light ray tracing algorithm to solve spot projection position and calculate matching deviation value;Morphology compensation module, according to the comparison result adjustment installation groove aperture size and generate three-dimensional eccentricity-preventing structure features, output reconstructed shell three-dimensional model, the present application solves the problem that traditional ideal size modeling is difficult to reflect the influence of assembly gap and solidification shrinkage.

Description

Technical Field

[0001] This invention relates to the field of automotive electronics and 3D modeling and simulation technology, specifically to a 3D modeling system for a car tailgate controller housing. Background Technology

[0002] With the increasing popularity of electric tailgates and foot-activated sensors in automobiles, there is a growing number of tailgate controllers that integrate optical emission and reflection sensing structures. These controllers have strict pre-set requirements for the assembly accuracy and optical path stability of the optical components inside the housing. How to balance structural manufacturability, assembly consistency, and sensing reliability during the 3D modeling stage has also become an important problem that needs to be solved in the current tailgate controller development process.

[0003] Traditional tailgate controller housing design currently relies mainly on the following methods: establishing a three-dimensional model of the housing based on ideal dimensions, setting optical element mounting slots according to nominal mating relationships, and improving assembly deviations through repeated mold repairs or experience adjustments after prototype production.

[0004] However, methods such as ideal size modeling, nominal fit design, and mold modification after prototyping all have certain drawbacks. For example, ideal size modeling usually only reflects static geometric relationships and is difficult to reflect the influence of mounting slot gap and adhesive curing shrinkage on the component's posture. Although nominal fit design can realize the coaxial setting of the mounting slot in the model, it is easy for the optical component to be eccentric or tilted due to tolerance fluctuations and shrinkage traction in actual assembly. The method of modifying the mold based on experience after prototyping has problems such as the positioning problem not being intuitive, long iteration cycle, and difficulty in simultaneously evaluating the matching effect between the light spot projection and the sensing area. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention provides a three-dimensional modeling system for automobile tailgate controller housings. Specifically, the technical solution of the present invention includes: The basic feature extraction module collects initial shell parameters, shell material properties, three-dimensional dimension data and mass property data of optical elements including light-emitting elements and light-returning elements, which contain the location information of the sensing area, and constructs a coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot contained in the optical element mounting slot, and generates basic topological feature data. The stress field simulation module acquires basic topological feature data and shell material properties, extracts the mating gap between optical elements and optical element mounting slots, injects random floating vectors within the tolerance range of the mating gaps, constructs curing shrinkage connection elements between optical elements and optical element mounting slots, calculates the stress distribution generated by curing shrinkage based on the curing shrinkage rate in the shell material properties, and calculates the offset attitude data of optical elements to generate assembly perturbation data. The performance evaluation module, based on the assembly perturbation data, substitutes the offset attitude data into the ray tracing algorithm to perform optical path simulation, calculates the projection position of the light spot in the sensing area, calculates the matching deviation value between the projection position and the center of the sensing area, and generates the coupling performance evaluation result. The morphology compensation module compares the matching deviation value in the coupling performance evaluation result with the preset deviation threshold, adjusts the aperture size of the optical element mounting slot according to the comparison result, generates a three-dimensional anti-eccentricity structural feature on the inner wall of the optical element mounting slot, and outputs a morphology-compensated reconstructed shell 3D model.

[0006] Preferably, the initial housing parameters include the geometric information of the optical element mounting slot; the optical element includes a light-emitting element and a light-returning element, the optical element mounting slot includes a light-emitting element mounting slot and a light-returning element mounting slot, and the sensing area is located on the light-returning element; the offset attitude data includes the offset angle and the offset displacement.

[0007] Preferably, the basic topology feature data includes the three-dimensional coordinates of the components, the geometric dimensions of the optical component mounting slot, and the identification of the coaxial constraint pairs; the assembly perturbation data includes the initial geometric perturbation matrix, the shrinkage stress distribution map, and the offset attitude data; and the coupling effectiveness evaluation results include the optical path propagation path, the light spot projection coordinates, and the matching deviation value.

[0008] Preferably, the basic feature extraction module includes: The data reading submodule collects initial shell parameters, shell material properties, and three-dimensional dimension data of optical components. It performs format verification and coordinate system alignment on the three-dimensional dimension data of optical components and generates a unified coordinate dimension sequence. The constraint construction submodule calls a unified coordinate dimension sequence to identify the central axis of the optical element, establishes a coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot, summarizes the coordinate system and constraint relationship, and generates basic topological feature data.

[0009] Preferably, the stress field simulation module includes: The gap floating submodule extracts the mating gap between the optical element and the optical element mounting slot based on the basic topological feature data, and injects a random floating vector within the tolerance range of the mating gap to generate an initial geometric perturbation matrix. The stress calculation submodule calls the initial geometric perturbation matrix and shell material properties to construct a virtual curing shrinkage connection element between the optical element and the optical element mounting slot, extracts the curing shrinkage rate from the shell material properties, and calculates the stress distribution under the action of asymmetric shrinkage tension caused by structural asymmetry. The offset calculation submodule, based on stress distribution and combined with the mass and geometric boundaries of the optical element, calculates the offset attitude data of the optical element from the coaxial constraint pair, and integrates them to generate assembly perturbation data.

[0010] Preferably, the performance evaluation module includes: The optical path tracing submodule extracts offset attitude data based on assembly perturbation data, updates the pose matrix of optical components in three-dimensional space, substitutes it into the ray tracing algorithm to perform virtual ray emission and refraction calculations, and generates the optical path propagation path. The deviation calculation submodule extracts the projection position coordinates of the light spot and the boundary coordinates of the sensing area based on the optical propagation path. It calculates the center coordinates of the sensing area based on the boundary coordinates, calculates the distance between the projection position coordinates and the center coordinates, defines the distance as the matching deviation value, and generates the coupling performance evaluation result.

[0011] Preferably, the shape compensation module includes: The threshold comparison submodule calls the coupling performance evaluation results, extracts the matching deviation value and compares it with the preset deviation threshold: if the matching deviation value is lower than or equal to the preset deviation threshold, the initial shell parameters are kept unchanged and the initial shell 3D model is output; if the matching deviation value is higher than the preset deviation threshold, the morphological reconstruction instruction is triggered. The feature derivation submodule, in response to the morphological reconstruction command, generates an inverse compensation value of equal magnitude and opposite direction as a structural compensation vector based on the offset angle and offset displacement in the offset attitude data. It adjusts the aperture size of the optical element mounting slot according to the structural compensation vector and generates a three-dimensional anti-eccentricity structural feature on the inner wall of the optical element mounting slot, updates the shell geometry topology, and generates a reconstructed three-dimensional shell model.

[0012] Preferably, the three-dimensional anti-eccentricity structure features a symmetrical guide channel structure extending axially along the inner wall of the optical element mounting groove and a limiting support rib structure protruding radially along the inner wall of the optical element mounting groove.

[0013] Preferably, the shape compensation module further includes: The mesh reconstruction submodule acquires the reconstructed 3D shell model, performs 3D mesh generation on the shell surface containing 3D anti-eccentricity structural features, performs mesh quality checks and topology optimization, eliminates interference surfaces and overlapping meshes, and outputs the final 3D shell mesh model after morphological compensation.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention establishes basic topological feature data, including the three-dimensional coordinates of the components, the geometric dimensions of the mounting slots, and the coaxial constraint pair identifiers, by collecting and uniformly processing the initial shell parameters, shell material properties, and three-dimensional dimensional data of the optical components. This enables the accurate construction of the ideal coaxial relationship between the mounting slots of the light-emitting components and the mounting slots of the light-returning components, and can unify multi-source model data under the same functional topological benchmark, thereby improving the realism of the modeling input and the reliability of subsequent analysis. 2. This invention extracts the fit gap between the optical element and the mounting slot, injects a random floating vector within the tolerance range, and calculates the stress distribution by combining the curing shrinkage connection element and the curing shrinkage rate in the shell material properties. This can effectively reflect the real offset mechanism when the element transitions from a free state to a locked state during the loading, dispensing, and curing process, and solves the problem that traditional ideal size modeling is difficult to reflect the effects of assembly gap and curing shrinkage. 3. This invention generates optical path propagation path, light spot projection coordinates and matching deviation value by substituting offset attitude data into ray tracing algorithm. It can directly convert structural offset into optical functional consequences for quantitative evaluation, avoiding the defect of traditional nominal fit design where only geometric coaxiality can be seen and it is difficult to judge the matching effect of sensing area. 4. This invention compares the matching deviation value with a preset deviation threshold and generates a reverse compensation value based on the offset angle and offset displacement. It adjusts the size of the mounting slot aperture and generates a symmetrical guide channel structure and a limiting support rib structure on the inner wall. This can simultaneously restrict the initial degree of freedom of assembly and balance the curing shrinkage traction, thereby improving the coaxial stability and sensing reliability of the optical element after assembly. 5. By further performing mesh generation, mesh quality inspection and topology optimization on the reconstructed shell 3D model, the present invention eliminates interference surfaces and overlapping meshes, ensuring that the compensated model not only has functional rationality, but also has analyzable, verifiable and deliverable engineering quality. This reduces the workload of repeated model modification based on experience after trial production, shortens the iteration cycle, and improves the modeling efficiency and development stability of the tailgate controller shell surface for mass production assembly. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a three-dimensional modeling system for a car tailgate controller housing provided in an embodiment of this application. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0017] A 3D modeling system for a car tailgate controller housing, the system comprising: The basic feature extraction module collects initial shell parameters, shell material properties, three-dimensional dimension data and mass property data of optical elements including light-emitting elements and light-returning elements, which contain the location information of the sensing area, and constructs a coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot contained in the optical element mounting slot, and generates basic topological feature data. The stress field simulation module acquires basic topological feature data and shell material properties, extracts the mating gap between optical elements and optical element mounting slots, injects random floating vectors within the tolerance range of the mating gaps, constructs curing shrinkage connection elements between optical elements and optical element mounting slots, calculates the stress distribution generated by curing shrinkage based on the curing shrinkage rate in the shell material properties, and calculates the offset attitude data of optical elements to generate assembly perturbation data. The performance evaluation module, based on the assembly perturbation data, substitutes the offset attitude data into the ray tracing algorithm to perform optical path simulation, calculates the projection position of the light spot in the sensing area, calculates the matching deviation value between the projection position and the center of the sensing area, and generates the coupling performance evaluation result. The morphology compensation module compares the matching deviation value in the coupling performance evaluation result with the preset deviation threshold, adjusts the aperture size of the optical element mounting slot according to the comparison result, generates a three-dimensional anti-eccentricity structural feature on the inner wall of the optical element mounting slot, and outputs a morphology-compensated reconstructed shell 3D model.

[0018] This embodiment provides an overall implementation mechanism for a 3D modeling system of a car tailgate controller housing, such as... Figure 1 As shown; specifically, this embodiment takes an electric tailgate controller development project as the main scenario. The controller is installed on the rear side of the tailgate interior panel. The housing integrates a light-emitting element and a light-reflecting element. The two are positioned by the mounting slot on the housing and are fixed by adhesive to complete mass production assembly. The light-emitting element can be an infrared emitting tube or a light-emitting diode chip combined with a lens, and the light-reflecting element can be a photodiode or an infrared receiving sensor. The sensing area in the three-dimensional model is defined as a two-dimensional polygonal outline or a three-dimensional bounding box geometry on the photosensitive surface of the light-reflecting element, which serves as the calculation target surface for ray tracing. Although the two mounting slots can be set as ideal coaxial in the 3D model during the design phase, problems such as ranging drift, echo sensing deviation, and projection ghosting often occur during the prototyping phase. The root cause is that the hole-axis clearance and curing shrinkage in the solid assembly will destroy the ideal coaxial state. Therefore, this system does not only generate static geometry, but also introduces assembly perturbation, curing shrinkage, and optomechanical coupling evaluation during the modeling process, so that the output model is directly oriented towards the final structure that can be manufactured, assembled, and achieve stable sensing. In the specific implementation process, the basic feature extraction module reads the initial shell parameters, shell material properties, and three-dimensional dimension data of the optical element; the initial shell parameters here include at least the aperture, depth, axial direction, and relative position of the two mounting slots, as well as the boundary position of the sensing area on the backlight element; the shell material properties include at least the material elasticity characteristics, shrinkage characteristics, and connection properties related to the dispensing interface; The system identifies the central axis of the optical element mounting slot and the backlight element mounting slot in three-dimensional space and establishes a coaxial constraint relationship between them. In engineering terms, this action corresponds to: first, determining the ideal mounting reference that the designer wants to achieve, as a reference baseline for subsequent judgment of offset risk; if a unified optical topology reference is not established in this step, even if stress simulation is performed later, it will be impossible to determine whether the offset is towards or away from the sensing area. Based on this, the stress field simulation module no longer assumes that the component and the mounting slot are perfectly fitted. Instead, it extracts the fit gap and simulates the possible floating state of the component within the tolerance range. This floating state can be expressed as a translation within the tolerance range or as a small-angle tilt around a local edge. Essentially, it corresponds to the degree of freedom of the component before it is cured after being inserted into the slot during mass production assembly. The system constructs a curing shrinkage connection element between the component and the groove wall to characterize the shrinkage traction effect when the dispensing material changes from a fluid state to a solid state. Specifically, based on the finite element method, the system constructs the curing shrinkage connection element as a spring damping unit or a thermal strain beam unit connecting the outer wall node of the optical component and the inner wall node of the mounting groove. By reading the volume shrinkage rate parameter in the material properties, it converts it into the initial tensile or compressive strain applied to the unit, thereby calculating the asymmetric tensile force. If the adhesive layer distribution is not absolutely symmetrical, the tensile force formed after curing will also be uneven, which can easily pull the component towards a certain side wall, causing the component axis to deviate from the groove axis; the system outputs offset attitude data accordingly, which at least reflects the offset angle and offset displacement, for subsequent optical evaluation. After receiving the assembly perturbation results, the performance evaluation module brings the updated component pose into the ray tracing process. This step is not only used to output the optical rendering visual results, but also to determine whether the real light path after the perturbation can still stably fall into the sensing area of ​​the return element. If the projection of the light spot falls near the center of the sensing area, it indicates that the design has the ability to tolerate assembly fluctuations. If the spot offset is greater than the preset threshold, and its edge is less than the set safe distance from the boundary of the sensing area or exceeds the boundary, it means that after mass production, it is easy to miss detection, false triggering or unstable ranging. The system further calculates the matching deviation value between the spot projection position and the center of the sensing area, and uses this value as a direct criterion for whether shape compensation is needed. The morphological compensation module executes different paths based on the comparison between the matching deviation value and the preset deviation threshold. If the deviation value is within the allowable range, the existing geometry is retained and the initial three-dimensional shell model is output. If the deviation value exceeds the limit, the mounting slot diameter is adjusted and a three-dimensional anti-eccentricity structural feature is generated on the inner wall. This feature is not an arbitrarily added protrusion, but is generated around two physical goals: limiting the initial degrees of freedom of assembly and balancing the curing shrinkage pull. The former is used to reduce the yaw space of the component before dispensing, and the latter is used to make the adhesive produce a more symmetrical shrinkage effect after curing. After processing by this module, the system outputs a reconstructed shell 3D model that already contains the manufacturing compensation intention. As an anomaly handling mechanism, if the input data lacks shell material properties, the system can perform conservative simulation using candidate parameters from a pre-set material library and mark the results as pending verification. If there is a significant conflict between the optical element size data and the initial shell parameters, such as the element's outer diameter being larger than the minimum diameter of the mounting slot, the simulation is paused and a geometric conflict warning is returned. If the boundary data of the sensing area is missing, the system can output only the structural offset risk conclusion without performing a complete coupled assessment to avoid providing distorted compensation suggestions when evaluation benchmarks are lacking.

[0019] Specifically, in the development of a foot-activated tailgate sensor controller for a certain sport utility vehicle, the design team initially used an ideal coaxial model for housing design. After the prototype was molded, some products experienced echo center drift during the adhesive curing process. After importing the initial housing parameters, light-emitting elements such as lenses, and the three-dimensional dimensional data of the return light elements using this system, the system established a coaxial reference between the light-emitting element mounting slot and the return light element mounting slot, and simulated the assembly gap and adhesive layer curing shrinkage. The results showed that although the axes in the geometric model were completely coincident, the emitted light spot shifted to one edge of the sensing area in the actual assembly state. After the system further automatically added an anti-eccentric structure to the inner wall and reduced the local invalid gaps, the light spot projection of the reconstructed model returned to the vicinity of the center of the sensing area under the same assembly disturbance. The purpose of this step is to transform the ideal coaxial axis on the design drawings into a real coaxial axis that still has stable optomechanical coupling capability after manufacturing, thereby realizing the transformation of the tailgate controller housing model from a static drawing tool to an intelligent modeling tool for mass production assembly.

[0020] Furthermore, the basic topology feature data includes the three-dimensional coordinates of the components, the geometric dimensions of the optical component mounting slots, and the identification of coaxial constraint pairs. The assembly perturbation data includes the initial geometric perturbation matrix, the shrinkage stress distribution map, and the offset attitude data. The coupling effectiveness evaluation results include the optical path propagation path, the light spot projection coordinates, and the matching deviation value.

[0021] This embodiment provides a data organization mechanism for the entire modeling process. Specifically, in the aforementioned tailgate controller project, if only the final compensated geometric results are retained without clarifying the structured expression of intermediate data, it will be difficult to support design review, process traceability, and subsequent batch optimization. Therefore, this embodiment standardizes the organization of three types of key data to form a traceable data link between 3D modeling, assembly simulation, and optomechanical evaluation. In the specific implementation process, the basic topology feature data is used to express the designer's original intention; among them, the three-dimensional coordinates of the components reflect the basic position of each optical component in the overall coordinate system, the geometric dimensions of the mounting slots reflect the actual assembly boundary reserved by the housing for each component, and the coaxial constraint pair identifiers are used to declare which mounting slots must be used as an optical alignment unit for linkage analysis. To illustrate with a simplified model, the center of the light-emitting element can be denoted as P1 and the center of the light-returning element as P2. If the two belong to the same optical link, the system will assign them the same constraint identifier C1. In this way, when the attitude of any element changes, the system can trace its impact on the entire optical path, rather than treating it as an isolated part. Assembly perturbation data is used to express the deviation process after the ideal design enters actual assembly. Among them, the floating vector matrix can be understood as the initial migration record of multiple components in multiple directions. For example, one component has a slight translation in the X and Y directions, and another component has a slight tilt around the local edge. The shrinkage stress distribution map is used to indicate which side has stronger tension and which ring has more concentrated stress after the adhesive layer is cured. The offset posture data is the final posture of the component obtained after interpreting the stress results in terms of structural response. The reason why this set of data is to be saved at the same time is that looking only at the final offset posture cannot determine whether the offset comes from excessive assembly gap or from unbalanced curing tension, and these two types of problems are different in subsequent compensation strategies. The coupling effectiveness evaluation results are used to express the consequences of the offset; among them, the optical path propagation path reflects the actual path of the light after it is emitted from the light-emitting element, after refraction, reflection or propagation, to the light-returning element; the light spot projection coordinates give the final landing point position; the matching deviation value transforms this landing point deviation into an evaluation quantity that can be directly used for compensation decisions; through this data organization method, the system can output the physical causes of structural offset and the corresponding optical function deviation results, avoiding repeated communication between different positions based solely on experience; As an anomaly handling mechanism, if a simulation fails to generate a reliable stress distribution map due to missing material parameters, the system can still output a floating vector matrix and a conservative attitude result based on geometric perturbation, and mark the data label as not including the effect of curing shrinkage; if the optical path fails to effectively reach the sensing area under a certain attitude, the spot projection coordinates can be marked as mismatched, and the matching deviation value is set as an out-of-bounds flag so that subsequent modules can directly trigger morphological reconstruction. Specifically, in the same tailgate controller project, the designers compared two versions of the shell model. The first version only saved the final Boolean result of whether it was qualified or not, while the second version fully saved the component coordinates, mounting slot dimensions, constraint markings, floating vector matrix, shrinkage stress distribution diagram, and light spot projection coordinates. Upon review, it was found that the second version could clearly locate that the adhesive layer thickness in the upper half of the backlight element mounting slot was too large, resulting in concentrated tension on the upper side after curing, which in turn caused the light spot to shift to the lower edge. Based on this, design adjustments could be made directly to the corresponding parts without having to re-traverse all structural assumptions. The purpose of this step is to establish a unified data representation method that runs through design, simulation, and compensation, thereby achieving interpretability, traceability, and reusability of the modeling process.

[0022] Furthermore, the basic feature extraction module includes: a data reading submodule, which collects initial shell parameters, shell material properties and optical element 3D dimension data, performs format verification and coordinate system alignment on the optical element 3D dimension data, and generates a unified coordinate dimension sequence; and a constraint construction submodule, which calls the unified coordinate dimension sequence, identifies the central axis of the optical element, establishes a coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot, summarizes the coordinate system and constraint relationship, and generates basic topological feature data.

[0023] This embodiment provides a mechanism for basic feature extraction. Specifically, in actual R&D processes, shell models typically come from structural design software, lens and reflector models may come from optical design software, and material properties often originate from process databases. If these input data are directly fed into subsequent simulations, the most likely problem is not the algorithm itself, but rather inconsistencies in coordinate systems, size units, or model origin definitions, ultimately leading to distorted simulation conclusions. Therefore, this embodiment sets up a data reading submodule and a constraint construction submodule in the basic feature extraction stage to first unify the models from various sources to the same coordinate system and data benchmark.

[0024] In the specific implementation process, the data reading submodule performs format verification on the input file; the verification here is not limited to whether the file can be opened successfully, but also includes whether the size unit is consistent, whether the origin of the part coordinate is located at the design reference position, and whether the component shape is completely closed, etc.; the system performs coordinate system alignment; for example, the shell model may be based on the mounting surface of the whole machine, the light-emitting element model may be based on its own optical center, and the light-returning element model may be based on the center of the package frame. The system needs to map these different references to the three-dimensional coordinates of the whole machine to form a unified coordinate dimension sequence. To simplify the model, if the housing mounting surface is located at the origin of the coordinate system, the original coordinates of the center of the light-emitting element are (10,2,5), and the original coordinates of the center of the light-returning element are (0,0,3) in another local coordinate system, then the system first transforms them to the same global coordinate system according to their respective assembly reference relationships, and then performs subsequent axis identification and position comparison.

[0025] The constraint construction submodule identifies the central axis of each optical element based on a unified coordinate dimension sequence. For rotationally symmetric elements, the axis can be extracted from their cylindrical or lens principal contours. For non-perfectly symmetric packages, the equivalent central axis can be determined by the design reference plane and the functional principal plane. After the axis identification is completed, the system establishes a coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot. This constraint is not to force the interference coincidence of the geometric model, but to declare that the two mounting slots should functionally maintain the same optical path center. In this way, when a subsequent mounting slot is offset due to assembly perturbations, the system can evaluate the consequences of its deviation relative to the axis of the other slot.

[0026] Furthermore, basic topological feature data is generated and summarized at this stage; its core function is to transform geometric primitives into structural objects that can be used for functional analysis; that is, the system assigns functional attributes to the extracted geometric primitives, defining them as light-emitting element mounting slots, which form a coaxial relationship with another mounting slot, and this relationship corresponds to the subsequent optical path coupling evaluation. As an anomaly handling mechanism, if a key contour of an optical component model is missing during data reading, making it impossible to reliably identify the central axis, the system can prompt the user to manually specify the axis or call a standard part template for replacement. If the units of different models are inconsistent, for example, one model uses millimeters and another uses micrometers, the system can automatically perform unit normalization during the import phase and retain the conversion log. If obvious penetration or suspension between the component and the shell is found after coordinate system alignment, the system will pause constraint construction and prompt the user to repair the initial assembly relationship first to avoid bringing geometric errors into subsequent simulations. Specifically, in this tailgate controller project, the model containing the initial housing parameters was provided by the structural team, while the model of the reflector element was provided by the supplier. The original coordinate definitions of the two were different. After the system was imported, it was found that the packaging origin of the reflector element was not at the optical center, but near the pin positioning angle. After the coordinate system was aligned, the system re-identified the central axis of the reflector element and established a unified coaxial reference with the mounting slot of the light-emitting element. In this way, even if there are local irregularities in the shape of the reflector element, the system can still perform analysis around the functional center rather than the packaging corners. The purpose of this step is to first eliminate the expression differences between multi-source modeling data, and then establish a unified topological benchmark for optomechanical functions, so as to ensure that subsequent assembly perturbation simulation has a real and reliable input premise.

[0027] Furthermore, the stress field simulation module includes: a gap floating submodule, which extracts the mating gap between the optical element and the optical element mounting slot based on the basic topological feature data, injects a random floating vector within the tolerance range of the mating gap, and generates an initial geometric perturbation matrix; The stress calculation submodule calls the initial geometric perturbation matrix and shell material properties to construct a virtual curing shrinkage connection element between the optical element and the optical element mounting slot, extracts the curing shrinkage rate from the shell material properties, and calculates the stress distribution under the action of asymmetric shrinkage tension caused by structural asymmetry. The offset calculation submodule, based on stress distribution and combined with the mass and geometric boundaries of the optical element, calculates the offset attitude data of the optical element from the coaxial constraint pair, and integrates them to generate assembly perturbation data.

[0028] This embodiment provides a mechanism for simulating the linkage between assembly perturbation and curing shrinkage. Specifically, when modeling based solely on ideal geometry, the most easily overlooked aspect is not the shape of the part itself, but rather the assembly lifecycle of insertion, dispensing, and curing. In actual production, components typically do not lose their degrees of freedom instantly after being inserted into the mounting slot. What truly determines their final orientation is often the fit gap, the adhesive filling path, and the curing shrinkage direction. Therefore, this embodiment divides the stress field simulation module into three sub-processes: gap floating, stress calculation, and offset solution, sequentially reconstructing the physical process of the component transitioning from a movable state to a cured and locked state.

[0029] In the specific implementation process, the gap floating submodule extracts the mating gap between the component and the mounting slot. This gap is inevitable in engineering because if there is no gap at all, the assembly difficulty will increase significantly. However, once the gap exists, the component may be biased to one side under the influence of gravity, insertion force or tooling posture. Therefore, the system assigns a random floating vector to the component within the tolerance range to express its initial offset possibility before curing. As a specific example, if a component can make small movements in the X and Y directions within the slot, where x is the specific displacement in the X direction and y is the specific displacement in the Y direction, then the system can record several candidate vectors such as the first candidate vector V1=(+x,0,0), the second candidate vector V2=(0,-y,0), and combine them to form an initial geometric perturbation matrix; this matrix is ​​not for demonstrating complex calculations, but is used to cover typical assembly postures such as left-side wall contact, right-side wall contact, and slight tilting; Based on this, the stress calculation submodule constructs a virtual curing shrinkage connection element between the component and the tank wall; its function is to characterize the pulling effect of the adhesive layer on the component during the curing process; if the thickness of the adhesive in the annular gap is uneven, or if a larger amount of adhesive is formed on one side due to different flow conditions, then the side will generate stronger shrinkage traction after curing. The system combines the shell material properties and adhesive shrinkage characteristics to output a stress distribution map; this stress distribution map is used to characterize the following physical mechanism: the final offset posture of the component is not entirely determined by the geometric parameters of the initial design, but depends on which side generates stronger shrinkage traction during curing; The offset calculation submodule calculates the final offset attitude corresponding to each typical perturbation state based on stress distribution, component mass, and geometric boundaries. Considering that the accidental wandering caused by a single random float cannot be directly used for mass production stability compensation, the system performs dominant feature extraction here: by traversing and statistically analyzing the spatial geometric distribution of all candidate final states derived from the initial geometric perturbation matrix, the system separates the systematic inherent offset features caused by the asymmetry between the slot structure and the adhesive distribution, while filtering out the random discrete deviations caused by simple initial gap wandering. For example, the optical component center coordinates of all candidate final states can be clustered using a spatial coordinate clustering algorithm to eliminate discrete outliers, and the center point of the main cluster containing the most coordinates is extracted as the systematic inherent offset feature. If the component mass is lower than the preset mass threshold and the support boundary is smaller than the preset width, it is more likely to be dragged by local asymmetric contraction tension and cause overall angular deflection; if the component boundary contact range is large or there is an initial limit in a local area, the offset is mainly manifested as a small local displacement rather than a large tilt angle; the system extracts the above-mentioned systematic inherent offset characteristics as the determined offset angle and offset displacement, and integrates them into assembly perturbation data, thereby providing a unique and stable deviation input benchmark for subsequent optical evaluation and reverse compensation; As an anomaly handling mechanism, if there is no effective adhesive layer area between a mounting slot and a component, for example, if the component is fixed by pure press fitting, the system can skip the construction of the curing shrinkage connector and instead generate geometric perturbation results based solely on the fit clearance. If tolerance information is missing, the system can use the default assembly tolerance in the process standard library for conservative analysis and mark it as the default operating condition. If the stress concentration area obtained in a simulation exceeds the material's tolerance range, the system can provide an early warning of the risk of localized shell cracking or adhesive layer peeling, instead of continuing to output conclusions that seem acceptable only from an optical perspective.

[0030] Specifically, during the trial production phase of the tailgate controller project, after the reflector element was inserted into the mounting slot, the operator applied adhesive from above. When the system reproduced this process, it was found that the adhesive on the upper side was more prone to accumulating, and the shrinkage traction formed after curing was mainly transmitted along the upper sidewall, causing the reflector element to produce an angular offset within a preset range. Although this offset is difficult to detect visually, its axis has deviated from the design coaxial reference. Through this simulation process, the design team was able to identify the problem and adjust the slot wall structure before mold opening, without having to wait until the optical test of the whole machine failed before going back to repair the mold. The purpose of this step is to bring the real perturbation mechanism in mass production assembly to the design stage for visualization and predictable analysis, so as to achieve early detection and targeted management of non-coaxial risks.

[0031] Furthermore, the performance evaluation module includes: a light path tracing submodule, which extracts offset attitude data based on assembly perturbation data, updates the pose matrix of the optical element in three-dimensional space, substitutes it into the ray tracing algorithm to perform virtual ray emission and refraction calculations, and generates the light path propagation path; The deviation calculation submodule extracts the projection position coordinates of the light spot and the boundary coordinates of the sensing area based on the optical propagation path. It calculates the center coordinates of the sensing area based on the boundary coordinates, calculates the distance between the projection position coordinates and the center coordinates, defines the distance as the matching deviation value, and generates the coupling performance evaluation result.

[0032] This embodiment provides a mechanism for evaluating optomechanical coupling performance. Specifically, knowing only how much displacement or tilt of a component has occurred does not directly indicate whether the product function has failed. This is because some offsets have little impact on the optical path, while others, although their geometric deviations are below the conventional assembly tolerances, may cause the light spot to leave the effective sensing area. Therefore, this embodiment uses an optical path tracking submodule and an offset calculation submodule to convert structural offsets into optical consequences that can directly reflect sensing performance.

[0033] In the specific implementation process, after receiving the offset attitude data, the optical path tracking submodule updates the pose of each optical element in three-dimensional space. The pose update here can be understood as repositioning the elements in the original ideal installation state to the actual position after assembly and curing. Before performing the optical path propagation path simulation, the system extracts the three-dimensional refractive index distribution parameters, surface reflectivity parameters, and medium parameters of the air gap inside the housing of the pre-configured optical elements. The system emits virtual light rays and simulates their propagation path in the interfaces of the light-emitting element, air gap, and return element. If the light-emitting element is tilted axially, the main beam of light will be deflected as a whole. If it is deflected laterally, the center of the beam may be shifted as a whole. The system generates the light path propagation path accordingly, which provides a basis for subsequent determination of whether the light spot can stably fall into the sensing area. The deviation calculation submodule extracts the projection position coordinates of the light spot from the optical propagation path and reads the boundary coordinates of the sensing area. The center of the sensing area is not a simple empirical point, but a functional center obtained according to the actual boundary definition. The system compares the projection position of the light spot with this center and calculates the Euclidean distance between the projection position coordinates and the center coordinates, defining this distance as the matching deviation value. To illustrate with a simplified model, if the boundary of the sensing area forms a rectangular region with its three-dimensional center coordinates denoted as C and the projection position coordinates of the emitted light spot denoted as L, the system calculates the straight-line distance between points L and C in three-dimensional space as the matching deviation value. When the matching deviation value is small, i.e., L is near C, it indicates that the sensing link is stable. When the distance between L and the boundary is less than the preset safety distance, it indicates that the functional margin is insufficient. When L exceeds the boundary, it indicates that the design no longer meets the usage requirements after assembly. In this way, the originally abstract offset attitude is transformed into a deviation consequence that is directly related to the final sensing effect and has been quantified. Compared to simple geometric verification, this evaluation method is more in line with the actual use mechanism of the tailgate controller. This is because users do not care whether the components are tilted by a few micro-scales during vehicle use, but only whether the foot kick sensor is sensitive and whether the tailgate responds stably. For R&D personnel, only by mapping the structural deviation to the light spot projection deviation can it be determined whether a certain structural modification has truly improved the functional reliability. As an anomaly handling mechanism, if ray tracing exhibits occlusion, total internal reflection anomalies, or a non-converging propagation path under a certain assembly posture, the system can mark this state as an invalid optical path and directly classify it as a mismatch situation. If the boundary of the sensing area changes due to differences in device versions, the system should prioritize reading the package boundary parameters of the current version to avoid misjudgment caused by using the center point of the historical version. If the size of the projected light spot itself is larger than the effective range of the sensing area, in addition to outputting the matching deviation value, the system can also provide a prompt indicating that there is a problem with the design of the light spot size mismatch, so as to avoid mistakenly attributing all risks to assembly offset.

[0034] Specifically, in this tailgate controller project, the previous simulation had already revealed a slight downward tilt of the reflector element. After the system substituted this posture into the optical path tracing, it was found that although the main axis of the beam was still pointing towards the reflector element, the center of the beam spot had shifted to the lower edge of the sensing area. Furthermore, under the combined conditions of vibration and temperature rise, the boundary of the beam spot tended to extend beyond the sensing area. Based on this, the design team confirmed that the problem was not just a shift, but that the shift had eroded the functional margin, so it was necessary to enter the morphological compensation stage. The purpose of this step is to translate the structural effects of assembly perturbations into optical functional effects, thereby enabling a quantitative prediction of the actual sensing reliability of the tailgate controller.

[0035] Furthermore, the morphology compensation module includes: a threshold comparison submodule, which calls the coupling performance evaluation results, extracts the matching deviation value and compares it with a preset deviation threshold; if the matching deviation value is lower than or equal to the preset deviation threshold, the initial shell parameters are kept unchanged and the initial shell 3D model is output; if the matching deviation value is higher than the preset deviation threshold, a morphology reconstruction instruction is triggered. The feature derivation submodule, in response to the morphological reconstruction command, generates an inverse compensation value of equal magnitude and opposite direction as a structural compensation vector based on the offset angle and offset displacement in the offset attitude data. It adjusts the aperture size of the optical element mounting slot according to the structural compensation vector and generates a three-dimensional anti-eccentricity structural feature on the inner wall of the optical element mounting slot, updates the shell geometry topology, and generates a reconstructed three-dimensional shell model.

[0036] This embodiment provides a mechanism for performing automatic morphological compensation based on evaluation results. Specifically, after completing the assembly perturbation and optomechanical coupling evaluation, if the system only gives the conclusion that a risk exists without further performing an executable structural reconstruction of the shell model, the designer still needs to rely on experience to repeatedly try and fail, making it difficult to achieve a closed-loop automated size compensation function. Therefore, this embodiment introduces a threshold comparison submodule and a feature derivation submodule, enabling the system to move from detecting offsets to automatically compensating for offsets.

[0037] In the specific implementation process, the threshold comparison submodule first determines the matching deviation value; the preset deviation threshold here is not arbitrarily set, but is established around the functional margin of the sensing area; specifically, the preset deviation threshold can be set as the absolute value of the difference between the minimum effective boundary inscribed circle radius of the sensing area and the maximum projection radius of the light spot, so as to ensure that the light spot can still fall completely into the sensing surface under assembly perturbation. If the deviation value does not exceed the threshold, it means that even if there are assembly perturbations, the light spot can still be stably within the effective sensing range. In this case, continuing to modify the shell shape may increase the manufacturing complexity. Therefore, the system keeps the initial shell parameters unchanged. Conversely, if the deviation value exceeds the threshold, it means that the current structure is difficult to guarantee stable coupling under mass production fluctuations. Therefore, the system triggers the shape reconstruction command. After receiving the reconstruction instruction, the feature derivation submodule obtains the determined offset angle and offset displacement after the random noise has been filtered out. Instead of performing a global reverse mapping of the offset, it generates an inverse compensation value of equal magnitude and opposite direction as a structural compensation vector for the inherent bias caused by the solidification shrinkage imbalance. This compensation vector is used to specifically adjust the initial positioning and stress balance of the mounting slot for the component from the design source. If the offset attitude data is mainly manifested as lateral displacement, the structural compensation vector extends to the opposite side, and the compensation effect is more reflected in reverse aperture compression and local limiting reinforcement to physically offset the initial bias. If the offset is mainly manifested as tilt angle, the compensation can be more reflected in reverse axial guidance, extension of the support boundary on the force-traction side, or symmetry of the adhesive path. As a specific example of structural offset, if a component is ultimately biased to the upper right due to local adhesive accumulation, the system generates a structural compensation vector in the lower left direction based on the reverse compensation value. Accordingly, a guiding constraint is added to the lower left side of the groove wall or a damping protrusion is added to the upper right side inner wall to reduce the local empty space. This allows the component to automatically obtain a reverse constraint force on the lower left side that counteracts the asymmetric traction force of curing during the loading and curing process, making it more difficult for it to become unstable to the upper right side during mass production assembly.

[0038] Compared to simply reducing the aperture, the compensation method in this embodiment emphasizes geometric topology updates. This is because some offsets do not simply come from excessive gaps, but from unbalanced adhesive shrinkage paths. In this case, simply reducing the aperture may lead to assembly difficulties, but may not necessarily improve the traction symmetry after curing. By deriving an anti-eccentric structure on the inner wall of the mounting groove, the system can both reduce the initial degrees of freedom and actively adjust the distribution and stress state of the adhesive in the groove, thereby achieving more targeted compensation.

[0039] As an anomaly handling mechanism, if the matching deviation value is close to the threshold, the system can simultaneously output two options for designers to choose from: maintaining the initial model and performing mild compensation, so as to balance between process feasibility and functional margin. If the compensation vector generated based on the offset attitude causes the mounting slot to interfere with other structures, the system should limit the compensation amplitude in this round and prompt to enter the next round of constraint optimization. If the deviation still exceeds the limit after a certain reconstruction, the system can enter the iterative compensation process, but a termination condition should be set to avoid repeated modifications in space-constrained scenarios without obtaining a manufacturable structure.

[0040] Specifically, in this tailgate controller project, the system evaluation found that the center of the light spot in the current model had exceeded the predetermined functional margin boundary, thus triggering morphological reconstruction. Based on the downward tilt and lateral displacement of the backlight element, the system generated a structural compensation vector in the opposite direction, made local fine adjustments to the aperture of the backlight element mounting slot, and automatically added guiding and limiting features to the inner wall. After reconstruction, the simulation was performed again, and the final state of the solidified element was closer to the ideal coaxial state, and the light spot returned to the vicinity of the center of the sensing area. The purpose of this step is to directly feed the coupling evaluation results into the shell geometry generation process in a closed loop, thereby achieving automated linkage from risk identification to structural correction.

[0041] Furthermore, the three-dimensional anti-eccentricity structure features include a symmetrical guide channel structure extending axially along the inner wall of the optical element mounting slot and a limiting support rib structure protruding radially along the inner wall of the optical element mounting slot.

[0042] This embodiment provides a specific derivative mechanism for a three-dimensional anti-eccentricity structure. Specifically, the previous implementation can automatically trigger morphological compensation, but if it is only abstractly described as generating an anti-eccentricity structure, there may still be problems with unclear implementation methods under extreme assembly conditions. Especially in structures with compact size and limited glue dispensing volume, such as tailgate controllers, the anti-eccentricity feature must improve the final state of the component without significantly disrupting the assembly channel or glue flow. Therefore, this embodiment refines the feature into a symmetrical guide channel structure and a limiting support rib structure to address the two types of defects: glue distribution imbalance and initial assembly sway, respectively.

[0043] In practical implementation, the symmetrical flow channel structure extends axially along the inner wall of the mounting groove. Its main function is not simply to reduce weight, but to provide a more balanced flow and spreading path for the adhesive. Without the flow channel, the adhesive tends to stagnate in some local high-resistance areas and accumulate in other areas, ultimately leading to uneven curing shrinkage. With the addition of the axially symmetrical flow channel, the adhesive is more likely to form a nearly uniform circumferential distribution along the groove wall, and the shrinkage pull after curing is closer to a symmetrical state, thereby reducing the tendency of the component to be pulled off one side. This structure is particularly suitable for scenarios where the dispensing inlet position is fixed and the adhesive viscosity is high. The limiting support rib structure protrudes radially along the inner wall of the mounting groove. Its main function is to provide an early contact boundary when the component is installed, and to compress the lateral degree of freedom of the component in the groove. During automatic generation, the system dynamically calculates the opening width and undercut depth parameters of the guide groove based on the magnitude of the structural compensation vector, and generates the three-dimensional geometric cross-sectional profile of the limiting support rib along the inner circumference of the optical component mounting groove according to the preset uniform array parameters. Without this structure, the component is more likely to stick to the wall, deviate, or be partially suspended before the adhesive has cured. After setting radial support ribs, the component will first form a mechanical limit with several symmetrical support points when entering the groove, thus getting closer to the center position; at the same time, the support ribs can also prevent the component from being pulled away from the design center instantaneously in the early stage of curing shrinkage; in other words, the guide groove focuses on controlling the distribution path of the adhesive, while the support ribs focus on constraining the initial positioning of the assembly. The combination of the two can simultaneously improve the risk of eccentricity before and after curing. From the perspective of evolution, although adjusting the aperture size alone can compress some gaps, under conditions of significant uneven adhesive shrinkage, there is still a possibility that the initial assembly will be coaxial but will become eccentric after curing. Conversely, if only the guide groove is added without supporting ribs, the initial posture of the component before dispensing may have already deviated from the center, and subsequent uniform curing can only lock the eccentricity. Therefore, this embodiment introduces two types of structures simultaneously to construct a continuous anti-eccentricity link from loading and positioning to curing and locking.

[0044] As an anomaly handling mechanism, if the installation slot size is too small to accommodate both the guide slot and the support rib simultaneously, the system can prioritize one of the following based on the source of the offset: for offsets dominated by adhesive shrinkage, the guide slot is retained first; for offsets dominated by wall adhesion during installation, the support rib is retained first; if the support rib height is too large, it may cause an abnormal increase in assembly resistance, so the system should provide rounded corner transitions and height constraints; if the guide slot is too deep, it may weaken the local strength of the slot wall, so the system needs to simultaneously check the integrity of the shell structure, and if necessary, reduce the slot depth or increase the number of circumferentially distributed ribs to disperse the impact.

[0045] Specifically, in this tailgate controller project, the system identified that the adhesive was more likely to stagnate above the mounting slot of the reflector element, and that the element tended to adhere to the right side wall when inserted. To address this, the system automatically generated axially symmetrical guide channels on the inner wall of the mounting slot, allowing the adhesive to diffuse to other areas in the circumference. At the same time, several symmetrical support ribs were generated in the radial position, so that the reflector element would first form a balanced contact with the support ribs after insertion, rather than directly adhering to the right side wall. After this structural compensation, the asymmetry of curing shrinkage and the initial wall-adhering deviation were both suppressed. The purpose of this step is to refine the anti-eccentricity compensation into a dual structural strategy targeting both the flow path and the limiting boundary, thereby achieving simultaneous management of the degrees of freedom before assembly and the shrinkage force after curing.

[0046] Furthermore, the morphology compensation module also includes: a mesh reconstruction submodule, which acquires the reconstructed 3D shell model, performs 3D meshing on the shell surface containing 3D anti-eccentricity structural features, performs mesh quality checks and topology optimization, eliminates interference surfaces and overlapping meshes, and outputs the final 3D shell mesh model after morphology compensation.

[0047] This embodiment provides a mesh reconstruction mechanism for final delivery. Specifically, in the aforementioned implementation process, the system has completed geometric morphological compensation. However, for actual R&D, the compensated model still needs to enter the mold review, finite element verification, process analysis, or CNC machining preparation stage. If the local mesh quality is not reconstructed after adding guide channels and support ribs, small facet flipping, interference surface residue, overlapping meshes, or acute angle distortion can easily occur, resulting in the subsequent software being unable to read stably and even affecting the generation of machining paths. Therefore, this embodiment sets up a mesh reconstruction submodule to perform engineering processing on the reconstructed shell model.

[0048] In the specific implementation process, the mesh reconstruction submodule performs local 3D mesh generation around the newly added anti-eccentricity structure region. Since the guide channel and support rib usually have characteristics of smaller than the preset size and multiple transition fillets, if the coarse mesh before compensation is still used, these structures are prone to distortion after discretization, which will affect the subsequent strength verification and process analysis. Therefore, the system increases the local mesh resolution for these regions and performs smooth connection of the transition region. The system performs mesh quality check to identify problems such as high aspect ratio elements, normal flipped elements, overlapping patches and non-manifold boundaries. Topology optimization is used to eliminate geometric discontinuities caused by Boolean operations or local features. Specifically, topology optimization here refers to geometric topology repair and cleanup operations on 3D mesh nodes and patch boundaries to eliminate overlapping meshes and gaps. For example, if a sharp transition is retained at the junction of the support rib and the groove wall, it may cause stress concentration and mesh distortion. The system can smoothly transition and re-layout the surface; for example, after the flow channel is derived, it may cause potential interference with the original reinforcing ribs or assembly buckle areas. The system will identify such conflicts in advance through interference surface detection and eliminate overlap and penetration without destroying the core compensation purpose. From an evolutionary perspective, simply completing structural compensation is insufficient to directly support the digital process before mass production; because structure represents the design intent, while a high-quality mesh is the carrier for engineering implementation; if this step is lacking, although the compensation result may be logically correct, it may not be usable by model flow analysis, structural analysis, or mold software due to model quality issues; therefore, this embodiment actually provides an engineering implementation basis for the aforementioned compensation mechanism.

[0049] As an anomaly handling mechanism, if there are still minor gaps or overlapping surfaces that cannot be automatically repaired after local reconstruction, the system can highlight the problem area and output a list of areas for manual review; if necessary simplifications are made to certain minor compensation features to meet mesh quality requirements, the system should simultaneously record the geometric differences before and after simplification to confirm that they do not exceed the functional tolerance; if a newly added structure causes the overall mesh size to be too large and affects the efficiency of subsequent analysis, the system can adopt a strategy of local refinement and moderate global simplification to control the model complexity while maintaining the accuracy of key anti-eccentricity areas.

[0050] Specifically, in this tailgate controller project, after the system automatically generated the flow channel and support ribs, it was found that the distance between the root of the support rib and an original inner reinforcing rib of the shell was less than the preset interference threshold, and an overlapping surface appeared after local Boolean operation; the mesh reconstruction submodule automatically rounded the corners of the boundary area and re-divided it, eliminating the interference surface, and outputting the final three-dimensional mesh model of the shell that can be used for mold review and subsequent finite element verification; thus, the design team no longer needs to perform a lot of manual surface finishing on the compensated model; The purpose of this step is to ensure that the shell model after morphological compensation is not only functionally sound, but also has analyzable, verifiable, and deliverable engineering quality in the digital manufacturing chain, thereby achieving a closed-loop completion from compensation design to final model output.

[0051] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A three-dimensional modeling system for a car tailgate controller housing, characterized in that, The system includes: The basic feature extraction module collects initial shell parameters, shell material properties, three-dimensional dimension data and mass property data of optical elements including light-emitting elements and light-returning elements, which contain the location information of the sensing area, and constructs a coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot contained in the optical element mounting slot, and generates basic topological feature data. The stress field simulation module acquires the basic topological feature data and the shell material properties, extracts the mating gap between the optical element and the optical element mounting slot, injects a random floating vector within the tolerance range of the mating gap, constructs a curing shrinkage connection element between the optical element and the optical element mounting slot, calculates the stress distribution generated by curing shrinkage based on the curing shrinkage rate in the shell material properties, and calculates the offset attitude data of the optical element to generate assembly perturbation data. The performance evaluation module, based on the assembly perturbation data, substitutes the offset attitude data into the ray tracing algorithm to perform optical path simulation, calculates the projection position of the light spot in the sensing area, and calculates the matching deviation value between the projection position and the center of the sensing area, generating a coupling performance evaluation result. The morphological compensation module compares the matching deviation value in the coupling performance evaluation result with a preset deviation threshold, adjusts the aperture size of the optical element mounting slot according to the comparison result, generates a three-dimensional anti-eccentricity structural feature on the inner wall of the optical element mounting slot, and outputs a morphologically compensated reconstructed three-dimensional model of the shell.

2. The three-dimensional modeling system for a car tailgate controller housing according to claim 1, characterized in that, The initial housing parameters include the geometric information of the optical element mounting slot; the optical element includes a light-emitting element and a light-returning element, the optical element mounting slot includes a light-emitting element mounting slot and a light-returning element mounting slot, and the sensing area is located on the light-returning element; the offset attitude data includes the offset angle and the offset displacement.

3. The three-dimensional modeling system for a car tailgate controller housing according to claim 1, characterized in that, The basic topology feature data includes the three-dimensional coordinates of the components, the geometric dimensions of the optical component mounting slots, and the identification of coaxial constraint pairs. The assembly perturbation data includes the initial geometric perturbation matrix, the shrinkage stress distribution map, and the offset attitude data. The coupling performance evaluation results include the optical path propagation path, the light spot projection coordinates, and the matching deviation value.

4. The three-dimensional modeling system for a car tailgate controller housing according to claim 1, characterized in that, The basic feature extraction module includes: The data reading submodule collects the initial shell parameters, the shell material properties, and the three-dimensional dimension data of the optical element. It performs format verification and coordinate system alignment on the three-dimensional dimension data of the optical element and generates a unified coordinate dimension sequence. The constraint construction submodule calls the unified coordinate dimension sequence, identifies the central axis of the optical element, establishes the coaxial constraint pair between the light-emitting element mounting slot and the light-returning element mounting slot, summarizes the coordinate system and constraint relationship, and generates the basic topological feature data.

5. A three-dimensional modeling system for a car tailgate controller housing according to claim 1, characterized in that, The stress field simulation module includes: The gap floating submodule extracts the mating gap between the optical element and the optical element mounting slot based on the basic topological feature data, and injects the random floating vector within the tolerance range of the mating gap to generate an initial geometric perturbation matrix. The stress calculation submodule calls the initial geometric perturbation matrix and the shell material properties to construct a virtual curing shrinkage connection element between the optical element and the optical element mounting slot, extracts the curing shrinkage rate from the shell material properties, and calculates the stress distribution under the asymmetric shrinkage tension caused by structural asymmetry. The offset calculation submodule, based on the stress distribution and combined with the mass and geometric boundaries of the optical element, calculates the offset attitude data of the optical element deviating from the coaxial constraint pair, and integrates them to generate the assembly perturbation data.

6. The three-dimensional modeling system for a car tailgate controller housing according to claim 1, characterized in that, The performance evaluation module includes: The optical path tracing submodule extracts the offset attitude data based on the assembly perturbation data, updates the pose matrix of the optical element in three-dimensional space, and substitutes it into the ray tracing algorithm to perform virtual ray emission and refraction calculations to generate the optical path propagation path. The deviation calculation submodule extracts the projection position coordinates of the emitted light spot and the boundary coordinates of the sensing area based on the optical path propagation path, calculates the center coordinates of the sensing area based on the boundary coordinates, calculates the distance between the projection position coordinates and the center coordinates, defines the distance as the matching deviation value, and generates the coupling performance evaluation result.

7. A three-dimensional modeling system for a car tailgate controller housing according to claim 2, characterized in that, The morphology compensation module includes: The threshold comparison submodule calls the coupling performance evaluation result, extracts the matching deviation value and compares it with the preset deviation threshold: if the matching deviation value is lower than or equal to the preset deviation threshold, the initial shell parameters are kept unchanged and the initial shell 3D model is output; if the matching deviation value is higher than the preset deviation threshold, a morphological reconstruction instruction is triggered. The feature derivation submodule, in response to the morphological reconstruction command, generates an inverse compensation value of equal magnitude and opposite direction as a structural compensation vector based on the offset angle and offset displacement in the offset attitude data. It adjusts the aperture size of the optical element mounting slot according to the structural compensation vector and generates the three-dimensional anti-eccentricity structural feature on the inner wall of the optical element mounting slot, updates the shell geometry topology, and generates the reconstructed shell three-dimensional model.

8. A three-dimensional modeling system for a car tailgate controller housing according to claim 7, characterized in that, The three-dimensional anti-eccentricity structure features a symmetrical guide channel structure extending axially along the inner wall of the optical element mounting slot and a limiting support rib structure protruding radially along the inner wall of the optical element mounting slot.

9. A three-dimensional modeling system for a car tailgate controller housing according to claim 7, characterized in that, The shape compensation module further includes: The mesh reconstruction submodule acquires the reconstructed shell 3D model, performs 3D meshing on the shell surface containing the 3D anti-eccentricity structural features, performs mesh quality checks and topology optimization, eliminates interference surfaces and overlapping meshes, and outputs the final shell 3D mesh model after morphological compensation.

Images