Complete vehicle trial-manufacture stage matching analysis method based on professional measurement software

Abstract

The invention discloses a matching analysis method for the trial-production stage of a whole vehicle based on professional measurement software, and the method comprises the steps: carrying out the trial-production and assembly of two workpieces, and judging whether the matching state of the assembly of the two workpieces accords with a design standard requirement or not; if not, scanning the workpiece to generate a point cloud, and acquiring triangularized patch data of the workpiece; obtaining a three-dimensional geometric data model of workpiece assembly according to the design standard of the workpieces, and fitting the triangularized patch data with the three-dimensional geometric data model to obtain the deviation of the two workpieces; comparing the deviation of the two workpieces with the workpiece design tolerance, and if the deviation of the two workpieces is greater than the workpiece design tolerance, judging that the matching state of the two workpieces does not conform to the design standard requirement; the trial-manufactured vehicle can meet the measurement requirements, so that the capital investment is reduced, and meanwhile, special equipment or tools are not needed to correspond to the problems; according to the invention, the test or measurement process is simple, and the process needs to be simplified enough because the trial-manufactured vehicle has many problems, so that the technicians can conveniently realize the matching requirements.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle assembly, and particularly to a matching analysis method for the whole vehicle trial production stage based on professional measurement software. Background Art

[0002] For the matching analysis and improvement of the vehicle loading state in cases such as component interference, abnormal gaps, and inconsistent states with the design after the trial production vehicle is assembled, due to the lack of a large number of special inspection tools invested in the trial production stage, the dimensional accuracy of the components and the body-in-white used for vehicle loading cannot be comprehensively mastered. Usually, when problems occur during or after assembly or during the whole vehicle test, it is necessary to trace back the reasons for dimensional anomalies in reverse. At this time, an intuitive matching analysis method is needed to find the true cause or adjust the vehicle state to meet the vehicle delivery requirements or test requirements. The above problems need to be solved urgently. Summary of the Invention

[0003] The purpose of the present invention is to provide a matching analysis method for the whole vehicle trial production stage based on professional measurement software to solve the problems mentioned in the above background art.

[0004] To achieve the above purpose, the present invention provides the following technical solution: A matching analysis method for the whole vehicle trial production stage based on professional measurement software, including:

[0005] Trial assemble two workpieces, and judge whether the matching state of the two assembled workpieces conforms to the design standard requirements;

[0006] If not, scan the workpieces to generate point clouds and obtain the triangulated patch data of the workpieces;

[0007] Obtain the three-dimensional geometric data model of the workpiece assembly according to the design standard of the workpiece, fit the triangulated patch data with the three-dimensional geometric data model, and obtain the deviation between the two workpieces;

[0008] Compare the deviation between the two workpieces with the design tolerance of the workpiece. If the deviation between the two workpieces is greater than the design tolerance of the workpiece, it is judged that the matching state of the two workpieces does not conform to the design standard requirements.

[0009] Further, if not, scan the workpieces to generate point clouds and obtain the triangulated patch data of the workpieces, and it further includes:

[0010] Set the calibration information and accuracy parameters of the scanning device based on the design standard requirements;

[0011] Adjust the shutter, second shutter parameters, and scanning resolution based on the environmental information;

[0012] Adjust the scanning grid, and set automatic hole filling and removal of isolated patches;

[0013] Select the scanning mode.

[0014] Further, it includes:

[0015] Scanning the workpiece and processing the acquired point cloud or triangulated patches;

[0016] Outputting and saving the workpiece surface data.

[0017] Further, obtaining the three-dimensional geometric data model of the workpiece according to the design standard of the workpiece, fitting the triangulated patch data with the three-dimensional geometric data model, and obtaining the deviation value between the two workpieces. It also includes:

[0018] Loading the triangulated patch data and the three-dimensional geometric data model;

[0019] Determining the fitting constraints, the best fitting method, and the reference frame according to the actual installation state of the workpiece;

[0020] Constructing reference elements for fitting alignment or coordinate system establishment on the three-dimensional geometric data model;

[0021] Constructing characteristic geometric elements on the three-dimensional geometric data model, measuring the dimensions of the workpiece using the characteristic geometric elements, and extracting the corresponding measurement values. Among them, the characteristic geometric elements include basic geometric elements such as circles, oblongs, cylinders, and spheres;

[0022] Comparing the actual position and the theoretical position of the surface points to obtain the surface deviation of their positions.

[0023] Further, comparing the actual position and the theoretical position of the surface points to obtain the surface deviation of their positions. It also includes:

[0024] Estimating and evaluating the workpiece deviation trend of the outer surface of the workpiece through cross-section analysis and color map analysis, and observing the surface deviation trend and the overall state.

[0025] Further, comparing the deviation between the two workpieces with the design tolerance of the workpiece. If the deviation between the two workpieces is greater than the design tolerance of the workpiece, it is determined that the matching state of the two workpieces does not meet the requirements of the design standard. It also includes:

[0026] The two workpieces are the first workpiece and the second workpiece respectively. The installation base of the first workpiece is the first base workpiece, and the installation base of the second workpiece is the second base workpiece. Determine whether the deviation between the first workpiece and the second workpiece is caused by the dimensional problems of the first base workpiece and the second base workpiece;

[0027] Obtaining the triangulated patch data of the first base workpiece and the second base workpiece through the scanning device;

[0028] Fitting the triangulated patch data with its corresponding three-dimensional geometric data model;

[0029] Obtain the first installation point where the first workpiece is installed on the first workpiece installation base, and the second installation point where the second workpiece is installed on the second workpiece installation base;

[0030] Based on the requirements of the design standard, obtain the workpiece installation point deviation between the first installation point and the second installation point through the fitting result;

[0031] Based on the requirements of the design standard, obtain the installation point design tolerance of the first installation point and the second installation point;

[0032] Compare the workpiece installation point deviation with the installation point design tolerance of the first installation point and the second installation point. If the workpiece installation point deviation is less than the installation point design tolerance, it is judged that the mismatch state between the first workpiece and the second workpiece and the design standard requirements is caused by the dimensional problems of the first workpiece and the second workpiece. If the workpiece installation point deviation is greater than the installation point design tolerance, it is judged that the mismatch state between the first workpiece and the second workpiece and the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in the deviation between the two workpieces.

[0033] Further, it includes:

[0034] When the assembly order of the first base workpiece and the second base workpiece is prior to that of the first workpiece and the second workpiece, the workpiece design tolerance is greater than the installation point design tolerance;

[0035] When the difference between the deviation of the two workpieces and the workpiece installation point deviation is not greater than the difference between the workpiece design tolerance and the installation point design tolerance, and the deviation of the two workpieces is less than the workpiece design tolerance, it is judged that the mismatch state between the first workpiece and the second workpiece and the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in the deviation between the two workpieces.

[0036] Further, judging that the mismatch state between the first workpiece and the second workpiece and the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, and further includes:

[0037] If it is determined that the mismatch state between the first workpiece and the second workpiece and the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in the deviation between the two workpieces, then obtain the triangulated patch data of the lower-layer workpiece of the first base workpiece and the second base workpiece through a scanning device, fit the triangulated patch data of the lower-layer workpiece with its corresponding three-dimensional geometric data model, and judge whether the deviation generated by the lower-layer workpiece is the cause of the dimensional problems of the first base workpiece and the second base workpiece.

[0038] Further, compare the deviation of the two workpieces with the workpiece design tolerance. If the deviation of the two workpieces is greater than the workpiece design tolerance, it is judged that the matching state of the two workpieces does not conform to the design standard requirements, and it includes:

[0039] If it is determined that the matching state of the two workpieces generated by the body size problems of the two workpieces does not conform to the design standard requirements, then the two workpieces are measured separately;

[0040] Focus on scanning the reference points, the first mounting point, the second mounting point, and the area with matching problems to form triangulated patch data. Use the reference points to align the triangulated patch data with the 3D geometric data model. After alignment, measure the deviations of the mounting points and the matching problem areas to obtain the deviation direction and deviation value of the deviations of the two workpieces;

[0041] Based on the design standard requirements, trim the two workpieces according to the deviation direction and deviation value. After trimming, re-measurement can be carried out to determine that the dimensional accuracy of the matching problem areas of the mounting points is not out of tolerance.

[0042] Furthermore, it includes:

[0043] If both workpieces are assembled by multiple layers of workpieces in the assembly order, then in accordance with the assembly order, detect layer by layer from the first assembled layer to the last assembled layer whether there are deviations in the assembly of each layer, and adjust and calibrate the generated deviations layer by layer.

[0044] Compared with the prior art, the beneficial effects of the present invention are: The trial-produced vehicle only needs to meet the measurement requirements of the present invention, thereby reducing capital investment. At the same time, there is no need to use special equipment or tooling to address such problems; The testing or measurement process of the present invention is simple. Since there are many problems with the trial-produced vehicle, the process should be simplified enough to facilitate technicians to meet their matching requirements. Brief Description of the Drawings

[0045] Figure 1 It is a flowchart of a matching analysis method for the whole vehicle trial production stage based on professional measurement software in an embodiment of the present invention;

[0046] Figure 2 It is a schematic diagram of poor matching between workpiece A0 and workpiece B0 in an embodiment of the present invention;

[0047] Figure 3 It is a schematic diagram of the triangulated patch data of workpiece A0 and workpiece B0 in an embodiment of the present invention;

[0048] Figure 4 It is a schematic diagram of the 3D geometric data model of workpiece A0 and workpiece B0 in an embodiment of the present invention;

[0049] Figure 5 It is a schematic diagram of the measurement data of workpiece A0 in an embodiment of the present invention;

[0050] Figure 6 It is a schematic diagram of the measurement data of workpiece B0 in an embodiment of the present invention;

[0051] Figure 7Schematic diagram of the measurement data of the first base workpiece A1 in the embodiment of the present invention;

[0052] Figure 8 Schematic diagram of the measurement data of the second base workpiece B1 in the embodiment of the present invention;

[0053] Figure 9 Schematic diagram of the measurement data of the lower-layer workpiece A2 in the embodiment of the present invention;

[0054] Figure 10 Schematic diagram of the color map analysis function in the embodiment of the present invention. Detailed implementation manners

[0055] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0056] In the description of the present invention, unless otherwise specified, "a plurality of" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0057] In the description of the present invention, it should be noted that, unless otherwise clearly defined and limited, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0058] Please refer to the accompanying drawings of the specification. As Figure 1 shown, the present invention provides a technical solution, a vehicle trial production stage matching analysis method based on professional measurement software, including the following steps:

[0059] S102. Trial-assemble two workpieces, and determine whether the matching state of the two assembled workpieces conforms to the design standard requirements;

[0060] Among them, the present invention uses conventional portable detection tools and relatively powerful professional measurement software, such as PolyWorks, to measure and match-analyze the areas with existing assembly problems. For example, after the trial assembly is completed, assuming there are two workpieces, workpiece A0 and workpiece B0, and it is found that there is a matching problem between workpiece A0 and workpiece B0, which does not conform to the design standard requirements. The matching problem may be manifested as interference, misalignment, abnormal gaps, inability to be installed smoothly, etc. As Figure 2 shown, workpiece A0 and workpiece B0 take the instrument panel and the door panel as examples respectively.

[0061] S104. If they do not match, scan the workpiece to generate a point cloud and obtain the triangulated patch data of the workpiece;

[0062] Specifically, based on the design standard requirements, set the calibration information and accuracy parameters of the scanning device;

[0063] Adjust the shutter, second shutter parameters based on the environmental information, and adjust the scanning resolution;

[0064] Adjust the scanning grid, and set the automatic filling of holes and removal of isolated patches;

[0065] Select the scanning mode.

[0066] Among them, in this embodiment, the process of digitalizing the workpiece surface preferably takes the MetraSCAN 3D750 laser scanner model of Creaform company as an example to illustrate its standardized data acquisition process; after running the VXelements software, check the calibration information of the device, and its accuracy requirement is less than 0.05 mm. If the accuracy is insufficient or the calibration information has expired, calibration should be carried out in time. Adjust the shutter and second shutter parameters until the scanning effect is reliable. The shutter is the main parameter that can act to adapt to the color of the outer surface of the workpiece and the ambient light intensity. When the scanning state shows over-saturation or under-exposure, it should be adjusted in time. Adjust the scanning resolution. The resolution determines the fineness of the scanned image, and the set coefficient should not be higher than 0.7 mm. Adjust the scanning grid options, which are divided into optimizing the scanning grid and simplifying the scanning grid. Optimizing the surface or points can reduce the influence of isolated points in the generated grid or point cloud. Among them, the optimized scanning grid depends on the actual situation, and the simplified scanning grid is set to 0. Set the automatic filling of holes and removal of isolated patches. The automatic filling of holes is set to 0, and the removal of isolated patches is set to 5. Judge whether it is necessary to change stations for scanning according to the size of the area to be scanned. When the scanning area is too large, that is, when the scanning device cannot complete the scanning without moving the tracker, necessary operations need to be carried out to increase the scanning range. Depending on the situation, select the combined scanning mode or the point distribution scanning mode. The combined scanning mode is to splice the overlapping areas after independent multiple scans. The point distribution scanning mode is to establish the position relationship of fixed reflective target points in space and then input them into the software to construct the three-dimensional relationship of the object to be measured. Both methods are available; as Figure 3As shown, workpiece A0 and workpiece B0 are triangulated patch data output by scanning. Among them, workpiece A0 and workpiece B0 take the instrument panel and door trim panel as examples respectively.

[0067] Specifically, scan the workpiece, process the obtained point cloud or triangulated patches; output and save the workpiece surface data.

[0068] Among them, use a scanner to scan the sample or workpiece, and pay attention that the scanning indication status is green during the process, and there are no defects such as explosion points and obvious wrinkles in the scanned pattern. Process the point cloud or triangulated patches, delete the unnecessary point cloud or triangulated patch areas, perform supplementary scanning on the positions with poor scanning effects, output an stl format file, and output and save the workpiece surface data.

[0069] S106. Obtain the three-dimensional geometric data model of the workpiece assembly according to the design standard of the workpiece, fit the triangulated patch data with the three-dimensional geometric data model, and obtain the deviation between the two workpieces;

[0070] Specifically, obtain the three-dimensional geometric data model of the workpiece according to the design standard of the workpiece, fit the triangulated patch data with the three-dimensional geometric data model, and obtain the deviation value between the two workpieces. It also includes:

[0071] Load the triangulated patch data and the three-dimensional geometric data model;

[0072] Determine the fitting constraints, the best fitting method and the reference frame according to the actual installation state of the workpiece;

[0073] Construct the reference elements used for fitting alignment or coordinate system establishment on the three-dimensional geometric data model;

[0074] Construct characteristic geometric elements on the three-dimensional geometric data model, use the characteristic geometric elements to measure the dimensions of the workpiece, and extract the corresponding measured values. Among them, the characteristic geometric elements include basic geometric elements such as circles, oblongs, cylinders, and spheres;

[0075] Compare the actual position and the theoretical position of the surface points to obtain the surface deviation of their positions.

[0076] Among them, excellently in this embodiment, the workpiece surface data evaluation process takes the PolyWorks general measurement and evaluation software of InnovMetric as an example to illustrate its standardized data evaluation process. First, run the PolyWorks software; create and save the workspace, input the three-dimensional geometric data model, such as CAD / CATIA model. The general model formats that can be input are iges and stp. Input the workpiece scan stl file and the saved workpiece surface data; determine the fitting alignment or coordinate system establishment method. Common methods include best fit, best fit with limited conditions, datum frame, etc., which are determined according to the actual workpiece installation state; construct and extract the elements for the datum. Construct the datum elements used for fitting alignment or coordinate system establishment on the CAD / CATIA model and extract relevant measurement values. Construct a circle on the model; observe whether the coincidence state of the CAD / CATIA model and the stl file meets the measurement and evaluation expectations after fitting alignment or coordinate system establishment. If it does not meet the expectations, replace the fitting alignment or coordinate system establishment method and the fitting alignment state; use features to measure the workpiece dimensions. The features include basic geometric elements such as circles, oblongs, cylinders, spheres, etc. According to the construction of the above simple geometric elements on the CAD / CATIA model and the extraction of relevant measurement values, the feature deviation can be obtained. When the feature has been constructed and cannot be extracted or the extraction is inaccurate, means such as anchoring, probing, and local fitting can be used for measurement and evaluation; measure the surface deviation at specific positions. For the measurement and evaluation of the surface, the actual position and the theoretical position of the surface points can be used to compare; as Figure 4 shown, the three-dimensional geometric data model of the assembly relationship between workpiece A0 and workpiece B0. Among them, workpiece A0 and workpiece B0 take the instrument panel and the door trim panel as examples respectively; Figure 5 is the measurement data of workpiece A0, Figure 6 is the measurement data of workpiece B0.

[0077] Specifically, by comparing the actual position and the theoretical position of the surface points, the surface deviation of its position is obtained, and it also includes:

[0078] Estimate and evaluate the workpiece deviation trend of the workpiece outer surface through cross-section analysis and color map analysis, and observe the surface deviation trend and the overall state.

[0079] Among them, the cross-section analysis and the color map function evaluate the workpiece outer surface. The above two functions can more intuitively observe the surface deviation trend and the overall state. Further, set the size, form and position tolerance (GD&T) control and tolerance for the evaluated elements, and output the size evaluation report for the matching analysis in the trial production stage.

[0080] S108. Compare the deviation between the two workpieces with the workpiece design tolerance. If the deviation between the two workpieces is greater than the workpiece design tolerance, it is judged that the matching state of the two workpieces does not meet the design standard requirements.

[0081] Among them, the matching problem between the covering workpiece A0 and the workpiece B0 is found, and it is clear that its matching state does not conform to the design state or experimental requirements. According to the actual situation of this state, a specific detection plan is set. Either non-contact measurement using an optical scanning device or contact measurement using a portable articulated arm coordinate measuring machine can be used. Here, because the point cloud output by the scanning device is easier to simulate the matching state in professional measurement software later, the optical scanning device is selected as an example to carry out the data acquisition work for matching analysis; it is necessary to digitally judge the degree of poor matching between the covering workpieces A0 and B0 to intuitively discover and express its poor matching state. The data can be used for subsequent analysis. Use the optical scanning device to scan the outer surfaces of the installed workpieces A0 and B0 and output triangulated patch data (the process of digitizing the workpiece surface), and then compare it with the design digital model and evaluate the dimensions (the process of evaluating the workpiece surface data). Because the matching problem in assembly is mostly to judge the spatial relative relationship between two assembled parts, it is not necessary to establish a coordinate system using the vehicle body benchmark (there are its main and auxiliary positioning at the four corners of the floor). Only the surrounding environment of the workpieces A0 and B0 needs to be used to establish a coordinate system for measurement. Because it is required to measure the value of the matching problem, the side with better subjective cognitive accuracy should be selected for fitting alignment. Usually, the closer the position is to the area under the front of the vehicle body, the shorter the dimension chain and the better the accuracy (the floor accuracy is greater than the side wall, and the front of the vehicle is greater than the rear). Therefore, we can make the triangulated patch data and the overall design digital model fit best in professional measurement software for the side with better subjective accuracy in the workpiece A0 or B0, or ignore the workpieces A0 and B0 themselves, and use the triangulated patch data of their surrounding assembly environment to fit best with the design digital model. After the fitting is completed, through conventional measurement, the deviation between A0 and B0 is measured as EA0 / B0. If this value is greater than the design tolerance PA0 / B0 between A0 and B0, it is determined that there is a matching problem, and the relevant data is recorded. The above deviation and tolerance should exist in three directions in the Cartesian coordinate system, that is, the X / Y / Z directions. For the sake of understanding, only one direction is taken for explanation, and the direction is not specifically enumerated. The process of digitizing the workpiece surface and the process of evaluating the data will be described independently later.

[0082] Specifically, compare the deviation between the two workpieces with the design tolerance of the workpiece. If the deviation between the two workpieces is greater than the design tolerance of the workpiece, it is judged that the matching state of the two workpieces does not conform to the design standard requirements. It also includes:

[0083] The two workpieces are the first workpiece and the second workpiece respectively. The installation base of the first workpiece is the first base workpiece, and the installation base of the second workpiece is the second base workpiece. Judge whether the deviation between the first workpiece and the second workpiece is caused by the dimensional problems of the first base workpiece and the second base workpiece;

[0084] Obtain the triangulated patch data of the first base workpiece and the second base workpiece through the scanning device;

[0085] Fit the triangulated patch data to its corresponding three-dimensional geometric data model;

[0086] Obtain the first installation point where the first workpiece is installed on the first workpiece installation base, and the second installation point where the second workpiece is installed on the second workpiece installation base;

[0087] Based on the design standard requirements, obtain the workpiece installation point deviation of the first installation point and the second installation point through the fitting result;

[0088] Based on the design standard requirements, obtain the installation point design tolerance of the first installation point and the second installation point;

[0089] Compare the workpiece installation point deviation with the installation point design tolerance of the first installation point and the second installation point. If the workpiece installation point deviation is less than the installation point design tolerance, it is judged that the mismatch state between the first workpiece and the second workpiece does not meet the design standard requirements due to the dimensional problems of the first workpiece and the second workpiece. If the workpiece installation point deviation is greater than the installation point design tolerance, it is judged that the mismatch state between the first workpiece and the second workpiece does not meet the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in the deviation between the two workpieces.

[0090] Wherein, in this embodiment, the first workpiece is workpiece A0, the second workpiece is workpiece B0, the first base workpiece and the second base workpiece are workpiece A1 and workpiece B1 respectively. Since both workpiece A0 and workpiece B0 are installed on other components, the dimensional abnormality problem cannot be attributed to the dimensional problems of workpiece A0 or workpiece B0. It may be that the deviation of the base parts under the covering parts A0 and B0 causes the overall dimensional abnormality, resulting in the matching problem between workpiece A0 and B0. Or there are dimensional problems in this set of systems, resulting in the above phenomenon. For example, workpiece A0 is installed on workpiece A1, and workpiece B0 is installed on workpiece B1. Therefore, it is necessary to analyze the spatial dimensional relationship among workpiece A0, A1, B0, and B1. In the case of more installation structures, it is also necessary to consider the lower-layer base workpieces A2 and B2, that is, the components on which workpiece A1 and B1 are installed; taking the instrument panel crossbeam as workpiece A1 as an example Figure 7 is the measurement data of workpiece A1. Taking the car door sheet metal as workpiece B1 as an example Figure 8Measurement data for B1; it has been determined that there is a matching deviation EA0-B0 between the covering workpiece A0 and B0. To further determine whether the deviation is caused by the body dimensions of the workpieces A0 and B0 or the dimensions of the underlying base workpieces A1 and B1, the covering workpieces A0 and B0 should be removed. During the removal process, it should be as gentle as possible to prevent damage to the workpieces. When the covering workpieces A0 and B0 are removed, the states of the underlying base workpieces A1 and B1 can be seen. At this time, use an optical scanning device to scan their states and output triangulated patch data, and perform the best fit with the design digital mock-up in professional measurement software. At this time, it should be noted that the fitting degree should be consistent with the fitting degree in step S106. The fitting states should be compared and there should be no obvious deviation. After the fitting is completed, what needs to be measured is the state of the joint installation points of workpiece A0 on workpiece A1. The same applies to workpieces B1 and B0. Through the measurement software, the workpiece installation point deviation EA1 / B1 between the base workpieces A1 and B1 can be obtained. At the same time, the design tolerance requirement between the base workpieces A1 and B1 is represented by PA1 / B1; when EA1 / B1 ≤ PA1 / B1, it can be understood that the installation position (on A1 and B1) deviation of the covering workpieces A0 and B0 meets the design requirement tolerance. Then the matching problem that appears should be attributed to the body dimensions of the covering workpieces A0 and B0. Dispose of the deviation of their bodies to repair the matching deviation after installation, and the process should proceed to step S07. When EA1 / B1 > PA1 / B1, it can be understood that the installation position (on A1 and B1) deviation of the covering workpieces A0 and B0 is higher than their design requirement tolerance, that is, the states of the base workpieces A1 and B1 affect the matching problem of the initially discovered workpieces A0 and B0, and the spatial relative positions of the workpieces A1 and B1 should be further analyzed.

[0091] Specifically, when the assembly order of the first base workpiece and the second base workpiece is prior to that of the first workpiece and the second workpiece, the workpiece design tolerance is greater than the installation point design tolerance;

[0092] When the difference between the deviation of the two workpieces and the deviation of the workpiece installation point is not greater than the difference between the workpiece design tolerance and the installation point design tolerance, and the deviation of the two workpieces is less than the workpiece design tolerance, it is determined that the non-compliance of the matching state of the first workpiece and the second workpiece with the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in the deviation of the two workpieces.

[0093] Among them, there is a special case. From the perspective of the assembly dimension chain, the assembly sequence of workpiece A0 and B0 is later than that of workpiece A1 and B1. It can be considered that workpiece A0 and B0 are at the more end of the dimension chain, so the range of PA0 / B0 is larger than that of PA1 / B1. When EA0 / B0 - EA1 / B1 ≤ PA0 / B0 - PA1 / B1, it can be considered that the relative value of the actual deviation is less than the relative value of the specified tolerance. Generally speaking, the deviation degree between the covering workpiece A0 and B0 is smaller than that between the base workpiece A1 and B1, that is, it can be determined that there is no out-of-tolerance dimension problem with workpiece A0 and B0. The matching problem mainly comes from the base workpiece A1 and B1. After analyzing workpiece A1 and B1 later and finding the root cause and adjusting to restore the vehicle, workpiece A0 and B0 do not need to be adjusted.

[0094] Specifically, determining that the matching state of the first workpiece and the second workpiece does not conform to the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in deviations between the two workpieces, and also includes:

[0095] If it is determined that the matching state of the first workpiece and the second workpiece does not conform to the design standard requirements is caused by the dimensional problems of the first base workpiece and the second base workpiece, resulting in deviations between the two workpieces, then the lower-layer workpieces of the first base workpiece and the second base workpiece are scanned by a scanning device to obtain the triangulated patch data of the lower-layer workpieces, and the triangulated patch data of the lower-layer workpieces is fitted with their corresponding three-dimensional geometric data models to determine whether the deviations generated by the lower-layer workpieces are the causes of the dimensional problems of the first base workpiece and the second base workpiece. As Figure 9 shown, the lower-layer workpiece A2 taking the installation point of the instrument panel crossbeam of the body-in-white as an example.

[0096] Among them, if it is determined that part of the reason for the matching problem of workpiece A0 and B0 comes from the spatial relative dimension state of workpiece A1 and B1, then more in-depth detection and analysis are required. At this time, workpiece AI and B1 should be regarded as covering workpieces, and their lower-layer workpieces A2 and B2 should be regarded as base workpieces, and the analysis process should be restarted.

[0097] Specifically, comparing the deviation between the two workpieces with the design tolerance of the workpieces. If the deviation between the two workpieces is greater than the design tolerance of the workpieces, it is determined that the matching state of the two workpieces does not conform to the design standard requirements, including:

[0098] Determining that the matching state of the two workpieces does not conform to the design standard requirements due to the dimensional problems of the two workpieces, then the two workpieces are measured separately;

[0099] Focus on scanning the reference point, the first installation point, the second installation point, and the area with matching problems to form triangulated patch data. Use the reference point to align the triangulated patch data with the 3D geometric data model. After alignment, measure the deviation of the installation point and the matching problem area to obtain the deviation direction and deviation value of the two workpieces.

[0100] Based on the design standard requirements, trim the two workpieces according to the deviation direction and deviation value. After trimming, re-measurement can be carried out to determine that the dimensional accuracy of the matching problem area of the installation point is within the tolerance range.

[0101] Among them, if it is determined that all the reasons for the matching problem between workpiece A0 and B0 come from the dimensional problems of their bodies, then the workpiece A0 and B0 should be measured separately. At this time, the workpiece is in the disassembled state, and the reference point, installation point, and the area with matching problems should be focused on scanning to form triangulated patch data. Use the reference point in the professional measurement software to align the triangulated patch data with the design digital model. After alignment, measure the deviation of the installation point and the matching problem area; according to the measured deviation direction and value, trim the workpiece A0 and B0 separately. After trimming, re-measurement can be carried out to determine that the dimensional accuracy of the matching problem area of the installation point is within the tolerance range; reinstall the covering workpieces A0 and B0, measure after installation, and analyze in the professional measurement software to check whether there is a matching problem. If still EA0 / B0 > PA0 / B0, re-measure and trim. If EA0 / B0 ≤ PA0 / B0, through measurement and appearance inspection, confirm that the matching problem of the workpieces A0 and B0 in this area is solved.

[0102] Specifically, if both workpieces are assembled by multiple layers of workpieces in the assembly order, then in the assembly order, detect whether there is deviation in the assembly of each layer from the first assembled layer to the last assembled layer, and adjust and calibrate the generated deviation layer by layer.

[0103] Among them, judge whether the repaired matching problem here is the matching problem of workpiece A0 and B0. If it is the first discovered matching problem, then this matching analysis and trimming end, and the subsequent trial production vehicles can be adjusted according to the values and directions adjusted this time before assembly. If it is not the first discovered matching problem of workpiece A0 and B0, for example, the matching problem solved this time is the matching problem of workpiece A1 and B1. If the matching problem solved this time is the next-level assembly matching problem, then the upper-level matching problem should be continued to be solved. For example, if the matching problem of the covering workpieces A1 and B1 in this round is solved this time, then the covering workpieces in this round should be regarded as the base workpieces of the upper level to solve the matching problem of the covering workpieces A0 and B0. When the initially discovered matching problem is solved, for example, the matching problem of the covering workpieces A0 and B0 is solved, then this matching analysis and trimming activity is completed.

[0104] The present invention mainly aims to make up for the step-by-step disassembly and measurement behavior due to the lack of dedicated forming inspection tools during the vehicle prototype trial production stage. On the premise of maximizing the optimization of funds, it can address the dimensional accuracy issues brought about by trial production and trial assembly. In addition to the above-mentioned conventional matching analysis methods, professional measurement software can be used for further analysis. The main contents are as follows:

[0105] Estimation of the spatial position deviation of workpieces by means of the installation point data: In professional measurement software, for the measurement results with formed data, different fitting alignments can be performed according to different needs. Thus, the installation points of the workpiece can be used as a reference for fitting alignment. Moreover, during the simulated assembly process, it is relatively easy to identify the force-bearing elements in the installation points. According to their force-bearing conditions, the fitting alignment directions of each installation point can be restricted. As a result, the data in the simulated assembly state can be achieved in the software, and the actual state after assembly can be predicted in advance. Then, the physical workpiece can be trimmed and optimized in terms of dimensions based on this, with the alignment direction restricted by specified points.

[0106] Estimation of the workpiece deviation trend by using the color map analysis function in professional measurement software: When multiple workpieces installed on the same whole appear (for example, the general assembly parts are assembled on the body-in-white), each piece is scanned and measured one by one. After the fitting alignment of the installation points, calculating the measurement values piece by piece is a cumbersome task. The color map analysis function in professional software can be used. After generating the color map, the color at the matching position can be observed to roughly judge the deviation situation through the color. When there is a color jump in the same direction for the area where multiple workpieces have a certain matching relationship, the risk of subsequent matching problems in this area is relatively high, and in-depth calculation and investigation should be carried out. When the color deviation is small, it means that the matching effect in this area and this direction after assembly is probably good. The workload of the matching analysis work can be reduced through its color map analysis function. The illustration of the color map analysis function is shown in the appendix Figure 10 。

[0107] Virtual matching analysis for vehicle prototype trial production or local prototype trial production assembly: After being proficient in fitting alignment with the force-bearing direction restricted by the installation points and color map deviation analysis, by means of the inspection and measurement data of the workpieces used for vehicle assembly before vehicle prototype trial production or local prototype trial production assembly, the whole vehicle or the local part can be combined in the professional measurement software in the assembly structure, and at the same time, it can be compared and measured with the design digital mock-up. The virtual matching work on the computer can be completed before assembly, so that the pre-judged matching problems can be processed in advance, ensuring the smoothness of the prototype vehicle assembly and improving the quality of the vehicle prototype trial production.

[0108] Although the embodiments of the present invention have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirits of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A matching analysis method for vehicle trial production based on professional measurement software, characterized in that: include: Trial-produce and assemble two workpieces to determine whether the matching status of the two workpieces meets the design standard requirements; If they do not match, the workpiece is scanned to generate a point cloud and obtain triangulated surface data of the workpiece; Acquire a three-dimensional geometric data model of workpiece assembly according to the design standard of the workpiece, fit the triangulated face data with the three-dimensional geometric data model, and obtain the deviation between the two workpieces; The deviation of the two workpieces is compared with the design tolerance of the workpieces. If the deviation of the two workpieces is greater than the design tolerance of the workpieces, it is judged that the matching state of the two workpieces does not meet the design standard requirements.

2. The matching analysis method for vehicle trial production based on professional measurement software according to claim 1 is characterized in that: If they do not match, the workpiece is scanned to generate a point cloud to obtain the triangulated patch data of the workpiece, which also includes: Based on the design standard requirements, set the calibration information and accuracy parameters of the scanning equipment; adjusting the shutter, the second shutter parameters, and the scanning resolution based on the environmental information; Adjust the scan mesh and set up automatic hole filling and isolated face removal; Select a scanning mode.

3. The matching analysis method for vehicle trial production based on professional measurement software according to claim 2 is characterized in that: include: Scan the workpiece and process the obtained point cloud or triangulated surface; Output workpiece surface data and save it.

4. The matching analysis method for vehicle trial production based on professional measurement software according to claim 1 is characterized in that: According to the design standard of the workpiece, a three-dimensional geometric data model of the workpiece is obtained, and the triangulated surface data is fitted with the three-dimensional geometric data model to obtain the deviation value of the two workpieces, which also includes: Load triangulated patch data and 3D geometric data models; Determine fitting constraints, optimal fitting method and reference frame according to the actual installation status of the workpiece; Constructing datum elements for fitting alignment or system building on 3D geometric data models; Construct characteristic geometric elements on the three-dimensional geometric data model, use the characteristic geometric elements to measure the size of the workpiece, and extract corresponding measurement values, wherein the characteristic geometric elements include basic geometric elements such as circle, long circle, cylinder, and sphere; By comparing the actual position of the surface point with the theoretical position, the surface deviation of its position is obtained.

5. The matching analysis method for vehicle trial production based on professional measurement software according to claim 4 is characterized in that: By comparing the actual position of the surface point with the theoretical position, the surface deviation of its position is obtained, which also includes: Through cross-section analysis and color image analysis, the workpiece deviation trend is estimated and evaluated on the outer surface of the workpiece, and the surface deviation trend and overall status are observed.

6. The matching analysis method for vehicle trial production based on professional measurement software according to claim 1 is characterized in that: Compare the deviation of the two workpieces with the design tolerance of the workpieces. If the deviation of the two workpieces is greater than the design tolerance of the workpieces, it is judged that the matching state of the two workpieces does not meet the design standard requirements, and also includes: The two workpieces are respectively a first workpiece and a second workpiece, the mounting base of the first workpiece is the first base workpiece, and the mounting base of the second workpiece is the second base workpiece, and it is determined whether the deviation of the first workpiece and the second workpiece is caused by the size problem of the first base workpiece and the second base workpiece; Acquire triangulated surface data of the first base workpiece and the second base workpiece by means of a scanning device; Fitting the triangulated patch data to its corresponding three-dimensional geometric data model; Acquire a first mounting point where the first workpiece is mounted on the first workpiece mounting base, and a second mounting point where the second workpiece is mounted on the second workpiece mounting base; Based on the design standard requirements, the workpiece mounting point deviation between the first mounting point and the second mounting point is obtained through the fitting result; Based on the design standard requirements, obtaining the installation point design tolerance of the first installation point and the second installation point; Compare the workpiece mounting point deviation with the mounting point design tolerances of the first mounting point and the second mounting point. If the workpiece mounting point deviation is less than the mounting point design tolerance, it is determined that the mismatch between the first and second workpieces and the design standard is caused by the size of the first and second workpieces. If the workpiece mounting point deviation is greater than the mounting point design tolerance, it is determined that the mismatch between the first and second workpieces and the design standard is caused by the size of the first base workpiece and the second base workpiece, causing the deviation between the two workpieces.

7. The matching analysis method for vehicle trial production based on professional measurement software according to claim 6 is characterized in that: include: When the first base workpiece and the second base workpiece are assembled before the first workpiece and the second workpiece, the workpiece design tolerance is greater than the mounting point design tolerance; When the difference between the deviation of the two workpieces and the deviation of the workpiece installation point is not greater than the difference between the workpiece design tolerance and the installation point design tolerance, the deviation of the two workpieces is less than the workpiece design tolerance, then it is judged that the matching state of the first workpiece and the second workpiece does not meet the design standard requirements and the deviation of the two workpieces is caused by the size problem of the first base workpiece and the second base workpiece.

8. The matching analysis method for vehicle trial production based on professional measurement software according to claim 7 is characterized in that: The method of determining that the matching state of the first workpiece and the second workpiece does not conform to the design standard requirement is caused by the size problem of the first base workpiece and the second base workpiece causing the deviation of the two workpieces, further comprising: If it is determined that the matching state of the first workpiece and the second workpiece does not meet the design standard requirements and the deviation between the two workpieces is caused by the size problem of the first base workpiece and the second base workpiece, the triangulated surface data of the lower workpiece of the first base workpiece and the second base workpiece is obtained by scanning the lower workpiece of the first base workpiece and the second base workpiece, and the triangulated surface data of the lower workpiece is fit with its corresponding three-dimensional geometric data model to determine whether the deviation generated by the lower workpiece is the cause of the size problem of the first base workpiece and the second base workpiece.

9. The matching analysis method for vehicle trial production based on professional measurement software according to claim 6 is characterized in that: Compare the deviation of the two workpieces with the design tolerance of the workpieces. If the deviation of the two workpieces is greater than the design tolerance of the workpieces, it is judged that the matching state of the two workpieces does not meet the design standard requirements, including: If it is determined that the matching state of the two workpieces caused by the problem of the body size of the two workpieces does not meet the design standard requirements, the two workpieces are measured separately; The reference point, the first mounting point, the second mounting point, and the matching problem area are scanned to form triangulated patch data. The triangulated patch data is aligned with the three-dimensional geometric data model using the reference point. After alignment, the deviation of the mounting point and the matching problem area is measured to obtain the deviation direction and deviation value of the deviation of the two workpieces. Based on the design standard requirements, the two workpieces are trimmed according to the deviation direction and deviation value. After trimming, they can be re-measured to determine that there is no out-of-tolerance situation in the dimensional accuracy of the matching problem area of ​​the installation point.

10. The matching analysis method for vehicle trial production based on professional measurement software according to claim 9, characterized in that: include: If both workpieces are assembled from multiple layers in an assembly sequence, then each layer is checked layer by layer from the first assembly layer to the last assembly layer in the assembly sequence to see if there is any deviation in the assembly, and the resulting deviation is adjusted and calibrated layer by layer.

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