An online absolute body clearance and size integrated measurement system

Abstract

The utility model belongs to the technical field of car body gap difference measurement, provide a kind of online absolute car body gap difference and size integrated measurement system, including car body positioning module, combined optical probe and data processing module;Combined optical probe includes rigid mounting bracket, at least two linear laser profile sensors, at least one area array three-dimensional measurement sensor and space pose tracker;Rigid mounting bracket includes center installation part and left wing part and right wing part, and obtuse angle included angle between left wing part and right wing part;Area array three-dimensional measurement sensor is installed in center installation part, and at least two linear laser profile sensors are correspondingly installed in left wing part and right wing part respectively;The geometric center of space pose tracker, the optical center of area array three-dimensional measurement sensor and the laser projection plane of at least two linear laser profile sensors are copoint.The utility model can realize the high-precision absolute measurement of functional dimension (FM), gap difference and constituent point simultaneously within production rhythm.

Description

Technical Field

[0001] This application relates to the field of vehicle body clearance and surface difference measurement technology, and in particular to an online absolute vehicle body clearance and surface difference integrated measurement system. Background Technology

[0002] In automobile manufacturing, surface finish defects (DTS) are a core indicator for measuring body assembly quality, directly impacting vehicle appearance, sealing, driving safety, and NVH performance. Simultaneously, the dimensional accuracy of key body components (such as fenders) directly determines the compatibility of subsequent parts and the overall vehicle assembly efficiency. The dimensional accuracy of the ZP5 body (i.e., the body-in-white with four doors, two hoods, and fenders installed) has a significant impact on the perceived quality of the vehicle and the assembly process in the final assembly workshop. Traditional methods relying on rework to eliminate out-of-tolerance dimensions not only reduce the first-pass yield but also significantly increase manufacturing costs. Furthermore, existing ZP5 online inspection equipment can only measure surface finish defects; it cannot measure functional dimensions (FM) that affect installation, nor can it output deviation source information for individual components of surface finish defects. Therefore, offline sampling monitoring is still necessary. Offline sampling disrupts the normal vehicle production schedule, and due to sampling lag and blind spots, defects cannot be fully controlled, further increasing subsequent rework costs.

[0003] Furthermore, traditional testing systems suffer from the following multiple bottlenecks:

[0004] 1) Existing DTS gap and surface difference detection equipment can only output gap and surface difference values, and cannot trace the root cause of the error, such as the dimensional deviation of the parts themselves, the assembly process deviation, or the tooling datum deviation. As a result, operators only know that there is an error but cannot accurately locate the source. They must use high-precision equipment such as coordinate measuring machines for secondary analysis after the equipment is taken off the production line, which increases the number of processes and inspection resources and seriously slows down the production cycle.

[0005] 2) In the traditional process, the detection of body clearance and surface difference and the detection of installation dimensions of key components (such as fenders) are separated into two independent workstations. Equipment debugging, vehicle transfer and other steps further consume time and manpower, which restricts the overall production efficiency. At the same time, traditional contact measurement is prone to scratching the body surface, and the accuracy is affected by contact pressure and environmental vibration, making it difficult to meet the requirements of high-precision online detection.

[0006] 3) The field of online measurement has long faced limitations in both relative and absolute measurement technologies:

[0007] (i) Relative measurement route: Regardless of whether a single-sided structured light sensor or a three-lens combination probe without spatial tracking is used, the following common problems exist:

[0008] Measurement accuracy is highly dependent on the repeatability of robot positioning, and robot accuracy is significantly affected by environmental factors such as workshop temperature, humidity, and vibration. It is difficult to maintain environmental stability in the production site. Therefore, this type of solution can only be used for trend monitoring and cannot replace offline absolute measurement.

[0009] Regular consistency comparisons and correlation analyses with offline measurements are required, and data compensation should be implemented accordingly. This process itself increases the frequency of offline measurements and interferes with normal production scheduling.

[0010] When a single-sided structured light is used to take pictures from a fixed angle, it is impossible to obtain a complete cross-sectional profile for positions with too small a gap or too large a surface difference. If multi-angle photography is used, the measurement time for a single piece will be greatly increased, making it difficult to meet the production line cycle time requirements.

[0011] (ii) Absolute measurement route: Absolute coordinate positioning can be achieved by integrating a spatial tracking unit on the probe, but the following problems still exist:

[0012] If a single-sided structured light sensor is used, the same problem of incomplete single-angle shooting at positions with small gaps / large surface differences and the need for multiple angle reshoots will be faced.

[0013] The encapsulation of the spatial tracking unit significantly increases the size of the probe, while areas such as the front compartment of a car have a compact structure and insufficient space for changing angles, resulting in some monitoring points being unreachable.

[0014] (III) Dual-line structured light sensor route: Although it can efficiently extract two-dimensional contour points and cloud computing gap surface difference, due to the limitation of data dimension, it can only obtain the relative size relationship and cannot obtain the absolute size deviation of the gap surface difference constituent points and FM constituent points in three-dimensional space. Therefore, it cannot meet the detection requirements of installation size and deviation traceability.

[0015] Finally, although a few three-lens probe solutions worldwide have attempted to integrate line laser and surface structured light, they are not equipped with spatial tracking devices and are essentially still relative measurements: on the one hand, they are greatly affected by the environment, their accuracy is insufficient to replace offline measurements, and they still require periodic data correction; on the other hand, they do not have the ability to analyze the three-dimensional deviation of gap surface differences, and the source of deviation still relies on offline processes.

[0016] In summary, there is currently no technical solution in the industry that can simultaneously integrate absolute measurement capabilities with integrated detection of gap surface differences and installation dimensions. This is a key gap that needs to be addressed in the online quality control of the ZP5 body and even the entire body-in-white. Utility Model Content

[0017] To address the shortcomings of existing technologies, this utility model provides an online absolute vehicle body clearance surface difference and dimension integrated measurement system, which can simultaneously perform high-precision absolute measurements of functional dimensions (FM), clearance surface differences and constituent points within the production cycle; and has the advantages of high integration, strong thermal stability, fast measurement speed and strong resistance to workshop environmental interference.

[0018] To achieve the above and related objectives, this utility model provides an online absolute vehicle body clearance surface difference and dimension integrated measurement system, including a vehicle body positioning module, a combined optical probe and a data processing module;

[0019] The vehicle positioning module is fixedly installed at the measurement station. The vehicle positioning module is equipped with a positioning reference component and a reference marker. The positioning reference component is positioned and engaged with the vehicle reference hole, and the reference marker has a fixed spatial position relative to the positioning reference component.

[0020] The combined optical probe includes a rigid mounting frame, at least two line laser profile sensors, at least one area array three-dimensional measurement sensor, and a spatial pose tracker.

[0021] The rigid mounting bracket includes a central mounting section and a left wing section and a right wing section located on both sides of the central mounting section, with the left wing section and the right wing section forming an obtuse angle.

[0022] A three-dimensional measurement sensor array is installed at the center mounting part, and at least two line laser profile sensors are respectively installed at the left wing and the right wing, and the laser projection planes of at least two line laser profile sensors intersect at the vehicle body area to be measured.

[0023] The spatial pose tracker is fixed to the end of a rigid mounting bracket. The geometric center of the spatial pose tracker, the optical center of the area array three-dimensional measurement sensor, and the laser projection planes of at least two line laser profile sensors are at the same point.

[0024] The data processing module is fixedly installed at the measurement station and connected to each sensor of the combined optical probe via cables.

[0025] Furthermore, the positioning reference component is a reference positioning pin, and the reference marker is a reference positioning ball; the reference positioning pin is used to engage with the reference hole on the vehicle body, and the axis of the reference positioning pin and the center of the reference positioning ball maintain a fixed relative position in space.

[0026] Furthermore, the angle between the left and right wings is 120°~150°.

[0027] Furthermore, at least two line laser profile sensors are equipped with detachable adjustment panels on their outer sides.

[0028] Furthermore, the spatial pose tracker has a hemispherical envelope structure; the positioning reference plane of the spatial pose tracker is parallel or coplanar with the mounting reference plane of the area array three-dimensional measurement sensor, and the two maintain a set constant distance, so that the geometric center of the spatial pose tracker, the optical center of the area array three-dimensional measurement sensor, and the laser projection planes of at least two line laser profile sensors intersect at the same spatial point.

[0029] Furthermore, it also includes a spatial tracking module, which comprises multiple spatial tracking cameras arranged around the measurement space. The fields of view of each spatial tracking camera collectively cover the motion trajectory of the combined optical probe, and each spatial tracking camera is connected to the data processing module via a cable.

[0030] Furthermore, it also includes a robot motion module, with a flange at the end of the robot motion module, and a combined optical probe rigidly connected to the flange.

[0031] Furthermore, it also includes a system calibration module, which comprises a calibration rod and a calibration ball;

[0032] The end of the robot motion module is equipped with a clamping structure, which is used to clamp the calibration rod;

[0033] The calibration rod has at least two calibration feature points that are fixed in space, and the calibration ball has a definite center position.

[0034] Furthermore, the data processing module includes a vehicle coordinate system mapping unit, an error analysis unit, and a report generation unit. Each unit is integrated into the same industrial control computer and connected through an internal bus. They are also electrically connected to each sensor of the combined optical probe via cables.

[0035] Furthermore, the vehicle positioning module, robot motion module, combined optical probe and data processing module are integrated into the same online inspection station, and the motion stroke of the robot motion module covers the vehicle body to be tested area on the vehicle positioning module.

[0036] The beneficial technical effects of this utility model are as follows:

[0037] This invention achieves simultaneous acquisition and unified judgment of vehicle body gap differences and key installation dimensions at the same online station by setting up a vehicle body positioning device with positioning reference parts and reference markers at the measurement station, combined with a combined optical probe mounted on the robot end effector. Specifically, the detection fields of at least two line laser contour sensors and at least one area array 3D measurement sensor converge in the same measured area. Combined with a spatial pose tracker and the calibrated preset spatial geometric relationship between each sensor, the system can uniformly convert and map the contour point cloud and 3D feature data acquired by multiple sensors to the same vehicle body coordinate system, directly register and compare it with the standard CAD model, and output the absolute deviation result. Therefore, this system breaks through the limitations of traditional DTS equipment, which can only output relative gap differences in its own coordinate system, cannot trace errors, and must rely on offline retesting. It can achieve a leap from "relative local measurement" to "absolute vehicle body coordinate system integrated measurement".

[0038] Furthermore, this invention combines the previously separate gap surface difference detection and functional dimension (FM) installation dimension monitoring (such as fender) into a single online station. This eliminates the need for vehicle transfer between different inspection stations and repeated debugging of multiple sets of equipment, effectively shortening the inspection cycle and improving the overall operating efficiency of the production line. Simultaneously, by utilizing a line laser contour sensor, a high-density contour point cloud of the gap and the three-dimensional spatial deviation of the matching parts can be acquired in a single moving scan. Compared to traditional surface structured light solutions that require multi-angle rotation for imaging, this significantly reduces the number of image acquisitions and data processing, further improving measurement efficiency while ensuring single-angle point cloud detection depth.

[0039] Furthermore, this invention utilizes the reference positioning pins and ball of the vehicle body positioning module, along with a spatial pose tracker, to construct a complete absolute measurement chain from the vehicle body's physical reference to the probe's spatial pose. This makes the system highly robust to environmental disturbances, eliminating the need for frequent data compensation or consistency calibration with offline equipment. This system can replace traditional offline sampling measurement methods, avoiding production scheduling interference and quality risks caused by sampling lag. It can directly support 100% online quality monitoring and real-time stop-line decision-making on the production line.

[0040] In summary, this utility model, through structured multi-sensor integration and unified coordinate mapping, can achieve automated detection, automatic report generation, and full-process data traceability, thereby significantly reducing manual intervention and improving the overall quality control level of vehicle body assembly while ensuring measurement accuracy and consistency. Attached Figure Description

[0041] The accompanying drawings, incorporated in and forming part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without inventive effort. In the drawings:

[0042] Figure 1 This is the general layout diagram of the integrated measurement system of this application;

[0043] Figure 2 This is a schematic diagram of the combined optical probe structure of this application;

[0044] Figure 3 This is a schematic diagram of the spatial tracking module structure in this application;

[0045] Figure 4 This is a schematic diagram of the system calibration module structure in this application.

[0046] Figure Labels

[0047] 1: Combined optical probe; 2: Spatial tracking module; 3: System calibration module; 4: Data processing module; 5: Robot motion module. Detailed Implementation

[0048] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should be understood that certain features of this invention (described in the context of separate embodiments for clarity) may also be provided in combination in a single embodiment. Conversely, multiple features of this invention (described in the context of a single embodiment for brevity) may also be provided separately or in any suitable combination or, where appropriate, in any other described embodiment of this invention. Certain features described in the context of various embodiments will not be considered essential features of those embodiments unless the embodiment is inoperable without those elements. The present invention is further illustrated below by specific examples; however, it should be noted that the specific process conditions and results described in the embodiments of this invention are for illustrative purposes only and should not be construed as limiting the scope of protection of this invention. All equivalent changes or modifications made in accordance with the spirit and essence of this invention should be covered within the scope of protection of this invention.

[0049] like Figures 1 to 4 As shown, this application provides an online absolute vehicle body clearance surface difference and dimension integrated measurement system, including a vehicle body positioning module, a combined optical probe 1 and a data processing module 4;

[0050] The vehicle positioning module is fixedly installed at the measurement station. The vehicle positioning module is equipped with a positioning reference component and a reference marker. The positioning reference component is positioned and engaged with the vehicle reference hole, and the reference marker has a fixed spatial position relative to the positioning reference component.

[0051] The combined optical probe 1 includes a rigid mounting frame, at least two line laser profile sensors, at least one area array 3D measurement sensor, and a spatial pose tracker. The rigid mounting frame includes a central mounting section and left and right wings located on either side of the central mounting section, with the left and right wings forming an obtuse angle. The area array 3D measurement sensor is mounted on the central mounting section, and the at least two line laser profile sensors are respectively mounted on the left and right wings, with the laser projection planes of the at least two line laser profile sensors intersecting the area to be measured on the vehicle body. The spatial pose tracker is fixed to the end of the rigid mounting frame, and the geometric center of the spatial pose tracker, the optical center of the area array 3D measurement sensor, and the laser projection planes of the at least two line laser profile sensors coincide.

[0052] The data processing module 4 is fixedly installed at the measurement station and connected to each sensor of the combined optical probe via cables.

[0053] Furthermore, the data processing module 4 of this application is connected to the sensor signals of each sensor in the combined optical probe 1, and is configured to convert and map the gap surface difference point cloud data and installation dimension data collected by each sensor to the same vehicle body coordinate system based on the spatial position information, spatial geometric relationship and preset calibration parameters of the reference marker, and compare it with the standard CAD model of the vehicle body to output the absolute deviation results of the gap surface difference and installation dimension.

[0054] Furthermore, the various modules of this application system work together to achieve absolute detection of body clearance surface differences, error source analysis, and synchronous detection of installation dimensions of key components such as fenders, completing the detection tasks of traditional two workstations and significantly improving measurement efficiency and quality control capabilities.

[0055] Furthermore, the positioning reference component in this application is a reference positioning pin, and the reference marker is a reference positioning ball. The reference positioning pin is used to insert and cooperate with the vehicle body reference hole. The relative positional relationship between the reference positioning ball and the reference positioning pin is determined by high-precision calibration to trace the data collected by the combined optical probe 1 back to the vehicle body coordinate system. Further still, the vehicle body positioning module of this application is suitable for carrying and positioning the vehicle body, and is the basis for realizing absolute measurement. It includes a positioning base, a positioning bracket, a reference positioning pin, and a reference positioning ball. The positioning base is fixedly connected to the ground by fasteners such as chemical bolts to ensure the overall stability of the system. The positioning bracket is detachably connected to the positioning base, and the horizontal position of the positioning bracket is adjustable. The reference positioning pin is located on the positioning bracket, and its size matches the preset vehicle body reference hole. Through the cooperation between the reference positioning pin and the vehicle body reference hole, rapid positioning and fixation of the vehicle body are achieved. The relative positional relationship between the reference positioning ball and the reference positioning pin is calibrated by high precision to ensure that the position of the vehicle body reference hole can be obtained by measuring the reference ball, thereby obtaining accurate vehicle body positioning and providing precise reference support for subsequent point cloud data conversion and error analysis.

[0056] Furthermore, this application also includes a robot motion module 5, with a flange at its end, and the combined optical probe 1 is rigidly connected to the flange. The robot motion module 5 is located outside the vehicle body positioning module and is used to drive the combined optical probe 1 to move along a preset trajectory, achieving full coverage of all detection positions on the vehicle body and ensuring no blind spots, including body gaps, fender mounting areas, etc., to achieve all-round detection.

[0057] Furthermore, such as Figure 2 As shown, the combined optical probe 1 of this application is the core component for data acquisition. It is integrated into the end of the robot motion module 5 and is used to complete the acquisition of body clearance surface difference contours and the measurement of key component installation dimensions in the same online workstation. The combined optical probe 1 of this application also includes a rigid mounting frame with a double-wing non-coplanar structure, including a central mounting part and left and right wings respectively located on both sides of the central mounting part. The left and right wings are arranged at an obtuse angle. The area array three-dimensional measurement sensor is mounted on the central mounting part through a three-sided positioning structure; two line laser contour sensors are respectively mounted on the left and right wings through a one-sided two-pin positioning structure and fixed with fastening bolts. The outer side of the two line laser contour sensors is provided with a detachable panel for fine-tuning the laser line position so that the laser lines emitted by the two line laser sensors are collinear. The spatial pose tracker is fixed on the rigid mounting frame and has a preset spatial geometric relationship with the two line laser contour sensors and the area array three-dimensional measurement sensor. The detection fields of the two intersect in the same measured area within the body's measurement area. Among them, the area array three-dimensional measurement sensor is an area structured light sensor or an area array laser sensor, and the measurement accuracy of the area array laser sensor is not less than 0.05mm.

[0058] During operation, the two line laser contour sensors employ a non-contact measurement method, enabling rapid and high-density acquisition of contour point cloud data of gaps and surface differences between areas such as the door and body, and the hood and fender. This fully reconstructs the true shape of the gaps and surface differences, providing ample data support for subsequent error analysis. The area array 3D measurement sensor is used to acquire installation dimension data of key body components, focusing on the fender mounting area. It can accurately obtain dimensional information such as the position coordinates of the fender mounting holes, the flatness of the mounting surface, and the docking accuracy with adjacent components, enabling real-time monitoring of the dimensions after fender installation. Each sensor establishes a unified transformation matrix through system calibration, mapping the data acquired by each sensor to the same body coordinate system, thereby achieving collaborative operation. The aforementioned combined optical probe 1 integrates gap and surface difference detection with installation dimension detection into one unit, eliminating the need for additional detection stations and effectively realizing the integration of detection tasks that originally required two separate stations.

[0059] Preferably, the angle between the left and right wings of this application is 120°~150°, and more preferably 135°, to balance the field of view coverage, measurement accuracy, and structural adaptability of the line laser contour sensor. The angle avoids both excessively small angles that would lead to excessive overlap of the two line laser fields of view, limiting the effective scanning range and failing to meet the one-time coverage requirements of large-sized vehicle body areas, and excessively large angles that would cause excessive divergence of the optical axes of the two sensors, resulting in insufficient length of the collinear laser lines converging in the same measured area and increased point cloud stitching errors. 135°, as a preferred value, ensures that the incident angle and reflection reception angle of the two lasers on typical curved surfaces such as vehicle body sheet metal are within the optimal range. While ensuring complete coverage of the measured area in the field of view intersection zone, it minimizes contour extraction distortion caused by the laser incident angle. Combined with the fine-tuning of the detachable adjustment panel, it further improves the coplanar accuracy and stitching consistency of gap surface differences and dimensional point clouds, adapting to the dual requirements of efficiency and accuracy in online measurement.

[0060] Optionally, this application can also change the three-lens combined probe (two line laser contour sensors at a 135° angle, one surface structured light sensor, and one spatial pose tracker) to a two-lens combined probe (two surface structured light sensors at a 135° angle and one spatial pose tracker). In this way, the dual 135° angled surface structured light sensors of this application can directly acquire high-density three-dimensional point clouds of the measured area. It can reconstruct the slit contour, surface difference, and local shape in one go without relying on continuous robot scanning or motion stitching, fundamentally eliminating the cumulative error of contour stitching caused by robot motion error and improving the spatial accuracy and repeatability of single sampling. Secondly, the two surface structured light sensors are arranged at a 135° intersection, so that the left and right fields of view converge and overlap at the measured feature, forming a complementary observation geometry similar to binocular stereo vision. The same slit edge, mounting hole, or mating surface can be captured by the two sensors from different angles at the same time, effectively eliminating optical occlusion and shadow blind spots under a single viewpoint, and significantly improving the measurement integrity of areas that are difficult to be completely covered by traditional single sensors, such as deep groove slits, the back of flanges, and the root of step differences. Furthermore, the structured light sensor itself possesses the ability to simultaneously acquire two-dimensional textures and three-dimensional topography. In a single exposure, it can extract edge features of gap surface differences and also acquire local three-dimensional dimensional features such as fender mounting holes and mounting surfaces. This achieves the same integrated detection function as the original solution in terms of structure, but eliminates the need for a separate line laser sensing channel, simplifying the rigid base layout, electrical interface, and calibration complexity inside the probe. In addition, the 135° wing angle has been optimized to ensure that the optical axes of the two sensors fully intersect in the same measured area while taking into account the incident / observation angles of the sensor and the measured vehicle body surface. This avoids insufficient parallax resolution caused by too small an angle and the problem of non-overlapping fields of view caused by too large an angle, achieving the best balance between measurement sensitivity, depth of field coverage, and structural compactness.

[0061] Furthermore, the data processing module 4 of this application is the core for realizing point cloud coordinate transformation and error analysis. It is communicatively connected to the line laser contour sensor and the area array 3D measurement sensor, respectively, to receive data collected by the sensors and to process, analyze, and store it. The data processing module 4 of this application includes a vehicle body coordinate system mapping unit, an error analysis unit, and a report generation unit. Each unit is integrated into the same industrial control computer and connected through an internal bus, and is electrically connected to each sensor of the combined optical probe 1 through cables. Among them, the vehicle body coordinate system mapping unit is configured to convert the two-dimensional contour point cloud collected by at least two line laser contour sensors into a three-dimensional point cloud based on the transformation matrix obtained by calibration, and to construct the vehicle body coordinate system in combination with the spatial pose tracker and reference markers. More specifically, this application obtains a transformation matrix through calibration, converting the two-dimensional contour point cloud data collected by the non-contact contour sensor into a three-dimensional point cloud. Then, a vehicle body coordinate system is constructed using a reference positioning sphere acquired by a laser array sensor. Through coordinate transformation, precise alignment between the point cloud data and the vehicle body coordinate system is achieved, breaking the limitation of traditional DTS inspection equipment that can only measure within its own coordinate system. This is the first application to realize gap and surface difference detection in the vehicle body coordinate system, providing a foundation for error source analysis. Furthermore, using a pre-set standard CAD model of the vehicle body, the DTS analysis algorithm calculates the feature point deviations of relevant parts from the collected point cloud data, clearly revealing the causes of the gap and surface difference deviations and the assembly relationships of the parts.

[0062] The error analysis unit in this application is configured to register and compare the converted 3D point cloud data with the standard CAD model of the vehicle body, and calculate the 3D deviation of the points constituting the gap surface difference, as well as the installation dimension deviation of key components. More specifically, through the error analysis unit, staff can directly obtain information on the source of errors without having to perform secondary measurements after the vehicle has rolled off the production line, greatly improving the efficiency and accuracy of quality control, facilitating the rapid implementation of targeted improvement measures, and reducing production costs.

[0063] The data storage unit in this application is used to store all data during the measurement process, including contour point cloud data, fender installation dimension data, error analysis results, measurement parameters, etc. It has a large storage capacity, supports long-term data traceability, and facilitates subsequent statistical analysis, quality review, and process optimization of the measurement data by the staff. The report generation module can automatically generate inspection reports that meet the enterprise standards. The reports contain information such as measurement values, inspection locations, and inspection part information, eliminating the need for manual organization. Staff can directly view the reports and make adjustments to the parts based on the reports, improving work efficiency.

[0064] This application report generation unit is used to automatically generate test reports and display the measurement results on a large display screen; if there are out-of-tolerance situations, it will trigger a quality stop and remind staff to handle the situation.

[0065] Furthermore, the spatial pose tracker of this application has a hemispherical envelope structure, which covers the outside of two line laser sensors and a surface structured light sensor, and is fixed to the end of a rigid mounting bracket. A set geometric distance is maintained between the positioning surface of the spatial pose tracker and the positioning surface of the area array 3D measurement sensor, so that the spatial pose tracker, the area array 3D measurement sensor, and at least two line laser contour sensors have a known common geometric center relationship. Furthermore, this application utilizes the hemispherical envelope structure to physically shield and protect the internal precision optical sensors, reducing the impact of external stray light and environmental interference on measurement accuracy. Moreover, the spatial pose tracker shares the same geometric center with multiple sensors, enabling the probe spatial pose acquired by the spatial pose tracker to directly and unambiguously represent the spatial pose of each sensor, avoiding the accumulation of errors from complex transformations between multiple coordinate systems. Combined with the inherent geometric constraints of the rigid mounting bracket, this common geometric center relationship can remain stable for a long time after system calibration, ensuring high accuracy and high repeatability when uniformly converting and mapping the two-dimensional / three-dimensional local data collected by each sensor to the vehicle body absolute coordinate system.

[0066] Furthermore, such as Figure 3 As shown, this application also includes a spatial tracking module 2, which includes multiple spatial tracking cameras arranged around the measurement space. The fields of view of each spatial tracking camera collectively cover the motion trajectory of the combined optical probe 1, used to acquire the spatial position and attitude of the spatial pose tracker in real time. More specifically, the spatial tracking module 2 of this application includes a carbon fiber column assembly and four spatial tracking cameras fixed on rigid support columns. The carbon fiber column assembly is arranged around the measurement space, and several spatial marker points are affixed to the carbon fiber column assembly. The four spatial tracking cameras are respectively installed at the four corners of the measurement station, and each spatial tracking camera is equipped with a two-degree-of-freedom fine-tuning mechanism. The fields of view of the four spatial tracking cameras collectively cover the motion trajectory of the combined optical probe 1.

[0067] Furthermore, such as Figure 4As shown, this application also includes a system calibration module 3, which includes a calibration rod and a calibration ball. The end of the robot motion module 5 is provided with a clamping structure for clamping the calibration rod. The calibration rod has at least two calibration feature points fixed in space, and the calibration ball has a defined center position. The robot motion module 5 is configured to move the calibration rod in space with a specific posture to calibrate the spatial accuracy of the spatial tracking module 2, and to drive the combined optical probe 1 to perform multi-angle measurements around the calibration ball to perform geometric center correction between the sensors and the spatial pose tracker. The preset calibration parameters mentioned above in this application come from the system calibration module 3. These parameters are the complete set of parameters obtained by the system calibration module 3 through a high-precision calibration process using a calibration rod, calibration ball, and reference positioning ball / pin. They include the intrinsic and extrinsic parameters of the spatial tracking camera, the fixed geometric relationship between the spatial pose tracker and each sensor, the internal model parameters of each sensor, and a complete set of transformation matrices and compensation values ​​from the probe pose to the vehicle body coordinate system. This is used to uniformly and accurately map the local point cloud and dimensional data collected by each sensor to the same absolute vehicle body coordinate system during online measurement. More specifically, the clamping structure in this application is a suction cup, used to grasp the calibration rod and move it in space with a specific pose to perform spatial accuracy calibration of the tracking camera.

[0068] Furthermore, the vehicle body positioning module, robot motion module 5, combined optical probe 1 and data processing module 4 of this application are integrated in the same online inspection station and are configured to simultaneously complete the gap difference measurement and installation dimension measurement within one vehicle body positioning cycle; and the motion stroke of the robot motion module 5 covers the vehicle body to be measured area on the vehicle body positioning module.

[0069] Furthermore, the data processing module 4 of this application also has a built-in coordinate transformation analysis unit, which is configured as follows:

[0070] The carbon fiber column envelopes the measurement space to achieve accuracy in the measurement space covered by the tracking camera, and the position transformation matrix T is obtained by calibration and unification to the vehicle body coordinate system;

[0071] Extracting the measurement point set based on the two-dimensional point cloud contour acquired by the line laser sensor. ;

[0072] The spatial tracking module 2 obtains the position matrix A of the vehicle body in the absolute coordinate system and the pose matrix B of the combined optical probe 1 in the absolute coordinate system.

[0073] The transformation matrix C between the measured surface and the combined optical probe 1 is obtained based on the line laser sensor;

[0074] Through matrix transformation The true coordinates of the measurement point set in the three-dimensional absolute vehicle body coordinate system are calculated and compared with the theoretical coordinates in CAD to output the dimensional deviation.

[0075] Furthermore, the working principle of the online absolute body clearance surface difference and dimension integrated measurement system of this application is as follows:

[0076] 1) The vehicle body to be tested is quickly positioned and fixed by inserting the reference positioning pin into the reference hole of the vehicle body. The reference positioning ball and the reference positioning pin are calibrated with high precision and have a known spatial position relationship, which together constitute the reference support for subsequent absolute measurement.

[0077] 2) The system obtains the corresponding vehicle model and body ID based on the RFID identification number and calls the corresponding detection program;

[0078] 3) The robot motion module 5 is located outside the vehicle body positioning module. It drives the end-effector combined optical probe 1 to move along a preset trajectory, so that the detection fields of at least two line laser contour sensors integrated on the rigid mounting frame and at least one area array three-dimensional measurement sensor (area structured light or area array laser sensor) intersect in the same measured area within the vehicle body to be measured area. Among them, the line laser contour sensor non-contactly collects the contour point cloud data of gaps and surface differences between the door and the body, the hood and the fender, etc., while the area array three-dimensional measurement sensor simultaneously collects the installation dimension data such as the position coordinates of the reference positioning ball and the fender mounting hole, the flatness of the mounting surface, and the docking accuracy. The spatial pose tracker moves with the rigid mounting frame and obtains the probe spatial pose in real time with the help of the peripheral spatial tracking module 2, and transmits the collected data to the data processing module 4 in real time.

[0079] 4) After receiving the above data, the data processing module 4 uses the transformation matrix obtained from calibration through the vehicle coordinate system mapping unit to convert the two-dimensional contour point cloud collected by the line laser sensor into a three-dimensional point cloud. Combined with the measurement data of the spatial pose tracker and the reference positioning ball, a vehicle coordinate system is constructed. Based on the preset spatial geometric relationship (including the common geometric center relationship) between each sensor on the rigid mounting bracket and the spatial pose tracker, the gap surface difference point cloud and the installation dimension data are uniformly converted and mapped to the same vehicle coordinate system. Subsequently, the error analysis unit registers and compares the converted three-dimensional point cloud with the standard CAD model of the vehicle body, calculates the three-dimensional deviation of the gap surface difference points and the installation dimension deviation of key components, and analyzes the installation dimension data of the fender to determine whether it meets the preset standard. This clearly presents the source of error and the assembly relationship of parts, avoiding secondary measurement after the vehicle is off the production line.

[0080] 5) The report generation unit automatically generates an inspection report and displays it on the large display screen. If there are any deviations, the quality line will be stopped to remind staff to handle the issue.

[0081] 6) The data storage unit saves complete measurement data to support traceability and process optimization. After the system automatically uploads the data, it transfers the car body out of the work area. Thus, the absolute detection of gap and surface difference and the monitoring of the installation dimensions of key components are completed simultaneously in one online workstation process, which traditionally requires two independent workstations. This significantly improves measurement efficiency and quality control capabilities.

[0082] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. An online absolute vehicle body clearance, surface difference, and dimensional integrated measurement system, characterized in that, It includes a vehicle positioning module, a combined optical probe (1), and a data processing module (4). The vehicle positioning module is fixedly installed at the measurement station. The vehicle positioning module is equipped with a positioning reference component and a reference marker. The positioning reference component is positioned and engaged with the vehicle reference hole. The reference marker has a fixed spatial position relative to the positioning reference component. The combined optical probe (1) includes a rigid mounting frame, at least two line laser profile sensors, at least one area array three-dimensional measurement sensor, and a spatial pose tracker; The rigid mounting frame includes a central mounting portion and a left wing portion and a right wing portion respectively disposed on both sides of the central mounting portion, wherein the left wing portion and the right wing portion form an obtuse angle. The area array three-dimensional measurement sensor is installed in the central mounting part, and at least two line laser profile sensors are respectively installed in the left wing and the right wing, and the laser projection planes of the at least two line laser profile sensors intersect in the vehicle body area to be measured. The spatial pose tracker is fixed to the end of the rigid mounting bracket, and the geometric center of the spatial pose tracker, the optical center of the area array three-dimensional measurement sensor, and the laser projection planes of at least two line laser profile sensors coincide. The data processing module (4) is fixedly installed at the measurement station and connected to each sensor of the combined optical probe (1) via cables.

2. The integrated measurement system according to claim 1, characterized in that, The positioning reference component is a reference positioning pin, and the reference marker is a reference positioning ball; the reference positioning pin is used to insert and cooperate with the reference hole of the vehicle body, and the axis of the reference positioning pin and the center of the reference positioning ball maintain a fixed relative position in space.

3. The integrated measurement system according to claim 1, characterized in that, The angle between the left wing and the right wing is 120°~150°.

4. The integrated measurement system according to claim 1, characterized in that, At least two of the aforementioned line laser profile sensors have detachable adjustment panels on their outer sides.

5. The integrated measurement system according to claim 1, characterized in that, The spatial pose tracker has a hemispherical envelope structure; the positioning reference plane of the spatial pose tracker is parallel or coplanar with the mounting reference plane of the area array three-dimensional measurement sensor, and the two maintain a set constant distance, so that the geometric center of the spatial pose tracker, the optical center of the area array three-dimensional measurement sensor, and the laser projection plane of the at least two line laser profile sensors intersect at the same spatial point.

6. The integrated measurement system according to claim 5, characterized in that, It also includes a space tracking module (2), which includes multiple space tracking cameras arranged around the measurement space. The field of view of each space tracking camera covers the motion trajectory of the combined optical probe (1). Each space tracking camera is connected to the data processing module (4) via a cable.

7. The integrated measurement system according to claim 6, characterized in that, It also includes a robot motion module (5), the end of which is provided with a flange, and the combined optical probe (1) is rigidly connected to the flange.

8. The integrated measurement system according to claim 7, characterized in that, It also includes a system calibration module (3), which includes a calibration rod and a calibration ball; The end of the robot motion module (5) is provided with a clamping structure, which is used to clamp the calibration rod; The calibration rod has at least two calibration feature points that are fixed in space, and the calibration ball has a definite center position.

9. The integrated measurement system according to claim 8, characterized in that, The data processing module (4) includes a vehicle body coordinate system mapping unit, an error analysis unit and a report generation unit. Each unit is integrated in the same industrial control computer and connected through an internal bus. They are also electrically connected to each sensor of the combined optical probe (1) through the cable.

10. The integrated measurement system according to claim 9, characterized in that, The vehicle positioning module, the robot motion module (5), the combined optical probe (1) and the data processing module (4) are integrated in the same online inspection station, and the motion stroke of the robot motion module (5) covers the vehicle body to be tested area on the vehicle positioning module.

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