Crankcase dimension visual measurement device

Abstract

The invention discloses a visual measurement device for the size of a crankcase, relates to the technical field of detection tools, and aims to solve the problems of multiple detection blind areas, insufficient measurement precision of complex curved surfaces / cavities, poor universality and the like of an existing device. The device comprises a measurement box main body, a vision measurement assembly, a support assembly and a control module, and the measurement box main body is provided with multiple chambers from top to bottom and is equipped with a heat dissipation and cleaning structure; the vision measurement assembly realizes multi-dimensional movement through multi-drive cooperation, and is matched with the self-adaptive light supplementing piece to guarantee the imaging quality; the control module integrates a multi-view image dynamic registration unit and a curved surface reconstruction unit, and accurately constructs a three-dimensional model; the supporting assembly can be matched with crankcases of different specifications. The full-dimension non-blind area measurement of the crankcase is realized, the detection precision of complex parts is greatly improved, the universality is high, the maintenance is convenient, and the efficient and accurate detection requirements of industrial batch production are met.

Description

Technical Field

[0001] This invention relates to the field of testing equipment technology, and in particular to a visual measurement device for crankcase dimensions. Background Technology

[0002] As a core load-bearing and transmission component of the engine, the dimensional accuracy of the crankcase, including its top surface, sides, crankshaft bores, and oil passages, directly determines the engine's assembly precision, operational stability, and service life. In industrial mass production, efficient and accurate multi-dimensional dimensional inspection of the crankcase is required. Traditional contact measurement methods suffer from low efficiency, easy damage to workpiece surfaces, and difficulty in accessing complex areas. Non-contact vision measurement technology, due to its high efficiency and non-destructive nature, is gradually becoming the mainstream.

[0003] However, existing visual measurement devices still face key technological bottlenecks: on the one hand, multi-view image registration for complex curved surfaces / cavities of crankcases relies on fixed algorithms, which fail to adapt to the material characteristics and structural differences of the workpieces, resulting in inaccurate feature point matching, large deviations in the 3D reconstruction model, and insufficient measurement accuracy of core cavity dimensions; on the other hand, a single motion mechanism struggles to achieve full-view coverage, resulting in blind spots in detection, and the support structure lacks versatility, failing to flexibly adapt to crankcases of different specifications, thus limiting detection efficiency and applicability. Therefore, a visual measurement device specifically designed to address the issues of measurement accuracy and full-dimensional coverage for complex parts is urgently needed. Summary of the Invention

[0004] The present invention aims to overcome the problems of existing crankcase measuring devices, such as numerous blind spots, low imaging accuracy, and insufficient measurement accuracy of complex curved surfaces / cavities, and provides a visual measuring device for crankcase dimensions.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a crankcase dimension visual measurement device, comprising: The main body of the measuring box is provided with a drive chamber, a detection support chamber and a cleaning limit chamber from top to bottom. The front sides of the measuring box are hinged with opening and closing doors that cooperate with the drive chamber and the detection support chamber. Multiple cooling fans that connect to the drive chamber are longitudinally distributed on both sides of the top surface. A cleaning groove that connects to the cleaning limit chamber is opened in the lower middle of one side. A limit platform is slidably assembled in the cleaning groove. A vision measurement component is assembled in the drive chamber and the detection support chamber to realize multi-dimensional image acquisition of the crankcase. A support assembly, assembled within the cleaning and limiting chamber, is used to support and position crankcases of different sizes. The control module is electrically connected to the vision measurement component, the support component, and the cooling fan, respectively. It is used to control the collaborative work of each component, receive image information collected by the vision measurement component and perform size calculation. The control module also integrates a multi-view image dynamic registration and surface reconstruction unit, which is used to calibrate the spatial coordinate deviation of each view image in real time and dynamically construct a three-dimensional model of the complex surface / cavity of the crankcase.

[0006] Preferably, the visual measurement component includes: A stepper motor is vertically mounted in a groove on the bottom surface of the drive chamber, and its output shaft extends through the detection support chamber. A rotating rod is mounted on the end of the output shaft of the stepper motor and placed in the detection support chamber. An electric push cylinder is mounted on the bottom surface, and a sliding groove is opened in the inner cavity. The sliding rod has an L-shaped cross-section and slides in conjunction with the sliding groove of the rotating rod. The sliding groove is vertically opened in the middle, and the bottom surface is equipped with a first drive motor. The first drive motor has an output shaft that passes through the bottom surface of the sliding rod and extends into its sliding groove, and is connected to a lead screw via a coupling. The lead screw is placed in the sliding groove of the sliding rod, and the other end is rotatably connected to the top surface of the sliding groove; The lifting platform slides in conjunction with the sliding groove of the sliding rod, and has a threaded hole on the other side of the top surface, through which it is threadedly connected to the lead screw. A rotating groove is also provided on one side of the top surface. The second drive motor is mounted at the rear end of the rotating slot of the lifting platform, and its output shaft passes through the rotating slot. A rotating block is rotatably mounted in the rotating slot of the lifting platform and has a rotating hole. The output shaft of the second drive motor passes through the rotating hole and is connected to the rotating block for transmission. A visual camera is mounted on one side of the rotating block; a supplementary lighting component is mounted on the lower outer side of the visual camera to provide auxiliary lighting for image acquisition.

[0007] Preferably, the supplementary lighting component is an adjustable supplementary lighting lamp, including a light intensity adjustment module. The control module is electrically connected to the light intensity adjustment module and is used to dynamically adjust the luminous intensity and illumination angle of the supplementary lighting component based on the reflective characteristics of the crankcase surface and image clarity feedback.

[0008] Preferably, the sliding mating surface of the sliding rod and the rotating rod is provided with a guide protrusion, and the inner wall of the sliding groove of the rotating rod is provided with a matching guide groove to limit the sliding direction of the sliding rod.

[0009] Preferably, the support component includes: The support platform is fixed to the bottom surface of the cleaning and limiting chamber, has a conical cross-section, and has multiple limiting grooves evenly spaced on its top surface. The cylinders are respectively assembled in multiple limiting slots of the support platform; the support plate is placed above the cylinders, the bottom surface is fixedly connected to the output shafts of multiple cylinders, and the top surface has multiple equally distributed fixing holes with different diameters to adapt to external clamping and limiting components of different specifications.

[0010] Preferably, the cylinder is equipped with a synchronization control module, which is electrically connected to the control module and is used to drive multiple cylinders to extend and retract synchronously under the command of the control module, so as to ensure that the support plate remains horizontally raised and lowered.

[0011] Preferably, the multi-view image dynamic registration and surface reconstruction unit of the control module includes: The coordinate calibration subunit is used to obtain the spatial position parameters of each visual camera and correct the coordinate offset of images from different viewpoints in real time. The feature point matching subunit is used to extract feature points of the complex surface / cavity of the crankcase in images from various perspectives, and achieves accurate cross-view feature point correspondence through a preset dynamic matching algorithm. The 3D reconstruction sub-unit is used to dynamically generate a 3D mesh model of complex surfaces / cavities based on the matched feature point data and the preset structural parameters of the crankcase. The dimensional data of complex parts are obtained by calculating the coordinates of the mesh nodes.

[0012] Preferably, the feature point matching subunit employs a dynamic matching algorithm to adaptively adjust the feature point extraction threshold and matching weight based on the surface material characteristics of the crankcase.

[0013] Preferably, the bottom surface of the cleaning limiting chamber is provided with an inclined guide surface, the lower end of which corresponds to the cleaning trough and is used to guide debris to collect in the cleaning trough; a sealing gasket is provided on the inner side of the switch door to enhance the sealing of the detection support chamber.

[0014] Preferably, the control module further includes an image preprocessing unit and a size calculation unit. The image preprocessing unit is used to perform noise reduction and enhancement processing on the images acquired by the vision camera, and the size calculation unit is used to accurately calculate the planar dimensions and the dimensions of the three-dimensional reconstructed curved surface, and output the measurement results.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. This solution integrates a multi-view image dynamic registration and surface reconstruction unit through a control module, combined with a dynamic matching algorithm adapted to material characteristics, which can calibrate coordinate offset in real time, accurately extract and match feature points, and dynamically generate a three-dimensional mesh model. With the denoising and enhancement functions of the image preprocessing unit, it effectively solves the pain point of insufficient measurement accuracy of core cavity dimensions, and greatly improves the accuracy and reliability of dimension detection of complex parts.

[0016] 2. This solution uses a stepper motor, an electric pusher cylinder, and dual drive motors to drive the vision camera to achieve multi-dimensional movement, fully covering the top surface, sides, and interior of the crankcase, completely eliminating blind spots in the inspection. At the same time, the adjustable supplementary light dynamically adjusts the light intensity and angle according to the surface reflectivity and image clarity, effectively eliminating shadows and overexposure, providing high-quality image data for dimensional calculation, and ensuring the stability of the measurement results.

[0017] 3. The support components of this solution are adjusted in height synchronously by cylinder. The support plate has multiple sizes of fixing holes, which can flexibly adapt to different sizes of crankcases. There is no need to customize special support parts, which reduces the testing cost. The inclined guide surface and sliding limit stage design of the cleaning limit cavity can guide the collection of debris and facilitate its discharge. Combined with the heat dissipation and maintenance structure of the drive chamber, it simplifies the equipment maintenance process and improves the efficiency of industrial batch testing.

[0018] In summary, this invention comprehensively solves the core problems of insufficient accuracy in complex parts, numerous blind spots, poor versatility, and inconvenient maintenance in existing crankcase measuring devices through the synergistic effect of multi-dimensional motion mechanisms, adaptive image processing algorithms, universal support structures, and convenient cleaning designs. It achieves simultaneous improvement in measurement accuracy, coverage, adaptability, and ease of maintenance, meeting the needs of efficient, accurate, and flexible testing in industrial mass production. Attached Figure Description

[0019] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the overall structure proposed in this invention; Figure 2 This is a half-sectional schematic diagram of the overall structure proposed in this invention; Figure 3 This is a schematic diagram of the visual measurement component structure proposed in this invention; Figure 4 The present invention proposes Figure 2 Enlarged diagram of part A in the middle; Figure 5 This is a control logic block diagram proposed in this invention; Figure 6 This is a schematic diagram of the control module proposed in this invention.

[0020] The components in the diagram are numbered as follows: 1. Measuring box body; 2. Opening and closing door; 3. Cooling fan; 4. Limiting platform; 5. Stepper motor; 6. Rotating rod; 7. Electric push cylinder; 8. Sliding rod; 9. First drive motor; 10. Lead screw; 11. Lifting platform; 12. Second drive motor; 13. Rotating block; 14. Vision camera; 15. Lighting component; 16. Cylinder; 17. Support plate. Detailed Implementation

[0021] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0022] Example: See Figures 1 to 6 A crankcase dimension visual measurement device according to the present invention includes: The measuring box body 1 is provided with a drive chamber, a detection support chamber and a cleaning limit chamber from top to bottom. The front sides of the measuring box body 1 are hinged with switch doors 2 that cooperate with the drive chamber and the detection support chamber. Multiple cooling fans 3 that communicate with the drive chamber are longitudinally distributed on both sides of the top surface. A cleaning groove that communicates with the cleaning limit chamber is opened in the lower middle of one side. A limit platform 4 is slidably assembled in the cleaning groove. The drive chamber has an inspection port on its side for easy maintenance of electrical components. A vision measurement component is assembled in the drive chamber and the detection support chamber to realize multi-dimensional image acquisition of the crankcase. A support assembly, assembled within the cleaning and limiting chamber, is used to support and position crankcases of different sizes. The control module is electrically connected to the vision measurement component, the support component, and the cooling fan 3, respectively. It is used to control the collaborative work of each component, receive the image information collected by the vision measurement component and perform size calculation. The control module also integrates a multi-view image dynamic registration and surface reconstruction unit, which is used to calibrate the spatial coordinate deviation of each view image in real time and dynamically construct a three-dimensional model of the complex surface / cavity of the crankcase.

[0023] In this application, the visual measurement component includes: The stepper motor 5 is vertically mounted in the groove on the bottom surface of the drive chamber, and its output shaft extends through the detection support chamber. The rotating rod 6 is mounted on the output shaft end of the stepper motor 5 and placed in the detection support chamber. An electric push cylinder 7 is mounted on the bottom surface, and a sliding groove is provided in the inner cavity. The sliding rod 8 has an L-shaped cross-section and slides in conjunction with the sliding groove of the rotating rod 6. The sliding groove is vertically opened in the middle, and the bottom surface is equipped with a first drive motor 9. The first drive motor 9 has an output shaft that passes through the bottom surface of the sliding rod 8 and extends into its sliding groove, and is connected to a lead screw 10 via a coupling. The lead screw 10 is placed in the sliding groove of the sliding rod 8, and the other end is rotatably connected to the top surface inside the sliding groove; The lifting table 11 is slidably fitted with the sliding groove of the sliding rod 8. A threaded hole is provided on the other side of the top surface, and it is threadedly connected to the lead screw 10 through the threaded hole. A rotating groove is provided on one side of the top surface; The second driving motor 12 is assembled at the rear end of the rotating groove of the lifting table 11, and the output shaft penetrates through the rotating groove; The rotating block 13 is rotatably assembled in the rotating groove of the lifting table 11. A rotating hole is provided. The output shaft of the second driving motor 12 penetrates through the rotating hole and is in transmission connection with the rotating block 13; The vision camera 14 is assembled on one side of the rotating block 13; The light supplementing component 15 is assembled on the outer side below the vision camera 14 and is used to provide auxiliary illumination for image acquisition; The vision camera 14 is an industrial area array camera, with the model MV-CA050-10GM, the resolution of 2592×1944 pixels, the frame rate ≥10fps, the lens focal length of 12mm - 25mm, and it is fixed on one side of the rotating block 13 by M4 bolts. The coaxiality error when the lens optical axis is perpendicular to the detection reference plane ≤0.1mm.

[0024] In this application, the light supplementing component 15 is an adjustable supplementary light, including a light intensity adjustment module. The control module is electrically connected to the light intensity adjustment module and is used to dynamically adjust the light emission intensity and illumination angle of the light supplementing component 15 according to the reflection characteristics of the crankcase surface and the image clarity feedback; The light supplementing component 15 is specifically an annular multi-spectral LED supplementary light, with the spectral range of 450nm - 650nm, the power of 10W - 20W, equipped with 16 - 32 LED lamp beads, and is coaxially installed with the vision camera 14 through a bracket (the distance is 50mm - 80mm); The light supplementing component 15 has a built-in light intensity adjustment module, integrating a PWM dimming circuit, with the dimming range of 0 - 100%, supporting electric adjustment of the illumination angle (the adjustment range is 30° - 120°), and communicating with the control module through the RS485 interface; Among them, the light intensity adjustment module dynamically adjusts parameters according to the reflection characteristics of the crankcase surface and the image clarity feedback. Specifically: Image clarity evaluation: The entropy method is used to calculate the image clarity E, and the formula is (where g is the gray level and p(g) is the probability of gray level g). Set the clarity threshold Eth. When E < Eth, it is determined that the image clarity is insufficient; Light intensity adjustment: Let the supplementary light intensity be I (the value range is 0 - 100%), and the initial light intensity , and the adjustment formula is: ; In the formula, , [[ID=2⑧]] respectively represent, and R is the reflectance; Illumination angle adjustment: When a reflective area is detected in the image (the proportion of pixels with a grayscale value ≥240 is ≥5%), the illumination angle of the supplementary lighting component 15 is controlled. Increase the angle by 5°-10°; when there are shadow areas (pixels with a grayscale value ≤30 account for ≥10%), the lighting angle... Reduce by 5°-10°.

[0025] In this application, the sliding mating surface of the sliding rod 8 and the rotating rod 6 is provided with a guide protrusion, and the inner wall of the sliding groove of the rotating rod 6 is provided with a matching guide groove to limit the sliding direction of the sliding rod 8.

[0026] In this application, the support component includes: The support platform is fixed to the bottom surface of the cleaning and limiting chamber, has a conical cross-section, and has multiple limiting grooves evenly spaced on its top surface. Cylinders 16 are respectively assembled in multiple limiting slots of the support platform; support plate 17 is placed above cylinders 16, with its bottom surface fixed to the output shafts of multiple cylinders 16, and its top surface having multiple equally spaced fixing holes of different diameters for adapting to external clamping and limiting components of different specifications; cylinders 16 are compact pneumatic cylinders, model CDQ2B50-200DZ, with a stroke range of 50mm-200mm, a rated working pressure of 0.4MPa-0.8MPa, and a positioning accuracy of ±0.1mm; cylinders 16 are equipped with a synchronous control module, integrating a flow control valve and a position sensor (model CS1-J), and are connected to an external air source through an air pipeline. The synchronous control module communicates with the control module through a CAN bus to realize the synchronous extension and retraction of multiple cylinders; The synchronization control module receives a height command determined according to the specifications of the crankcase to be tested, and achieves synchronous lifting and lowering through the following steps: The height of the crankcase to be tested is identified from the height command and recorded as follows: ; Position acquisition: The position sensors of each cylinder 16 acquire the current stroke in real time. (u=1,2,3,4, corresponding to 4 cylinders), sampling frequency 100Hz, transmitted to the synchronization control module. Error calculation: calculate the error between the stroke of each cylinder and the target stroke. ; Flow regulation: based on the error between cylinder stroke and target stroke. Adjust the opening degree of the flow control valve; the opening degree is proportional to the error, i.e. The larger the cylinder diameter, the greater the opening. The PID algorithm is used to dynamically adjust the cylinder diameter to ensure that the cylinder extension and retraction speeds are synchronized, ultimately achieving a synchronization error that is less than the preset synchronization error threshold.

[0027] In this application, the multi-view image dynamic registration and surface reconstruction unit of the control module includes: The coordinate calibration subunit is used to acquire the spatial position parameters of each visual camera 14 and correct the coordinate offset of images from different viewpoints in real time. Specifically: The motion mechanism feedback parameters of the vision measurement component (rotation angle θ of stepper motor 5, extension / retraction L of electric cylinder 7, lifting / lowering H of first drive motor 9) are combined with the intrinsic parameters (focal length f, pixel size s) and extrinsic parameters (camera mounting position coordinates) of vision camera 14. ), calculate the spatial coordinates of the image from each viewpoint, according to the formula , , Calculate the spatial coordinates of the camera from each viewpoint In the formula, X, Y, and Z are the calibrated camera spatial coordinates. These are the initial position coordinates of the camera; Real-time calibration is performed using a preset calibration plate, with a correction amount Δ = |measured coordinates - true coordinates|, ensuring that the coordinate calibration error does not exceed the preset calibration error threshold, and establishing a unified equipment coordinate system O-XYZ (origin O is the center of the bottom surface of the main body 1 of the measuring box). This coordinate calibration subunit is used to correct the coordinate offset caused by the movement error of the mechanism and the installation error of images from different perspectives in real time, establish a unified equipment coordinate system, and ensure the spatial coordinate consistency of multi-view images. The feature point matching subunit is used to extract feature points of complex surfaces / cavities of the crankcase in images from various viewpoints. It achieves accurate cross-viewpoint feature point matching through a pre-defined dynamic matching algorithm, specifically: An adaptive threshold edge detection algorithm is used to extract edge points and curvature abrupt change points in the image as feature points. The dynamic extraction threshold T is dynamically adjusted according to the surface material characteristics of the crankcase. In the formula, The baseline threshold is used, where R is the reflectivity of the crankcase surface, which can be calculated from the average grayscale value of the image acquired by the vision camera 14, and S is the surface roughness, which is input by the user or called from the preset material parameter library. These represent the weighting coefficients corresponding to the surface reflectivity and roughness of the crankcase, respectively. An improved K-nearest neighbor matching algorithm is used to assign dynamic weights ω to feature points in different regions, as shown in the formula: In the formula, , These are the weights corresponding to the curvature of the region where the feature point is located and the distance coefficient between the feature point and the image center, respectively. C is the curvature of the region where the feature point is located (C > 1.5 is a high curvature region, C ≤ 1.5 is a flat region), and D is the distance coefficient between the feature point and the image center (D = 1 - d / Dmax, where d is the distance from the feature point to the image center, and Dmax is the half-length of the image diagonal). Matching distance is retained during matching. Feature point pairs, To minimize the matching distance, feature points of complex surfaces / cavities of the crankcase (such as crankshaft holes and oil passages) are extracted through feature point matching subunits to achieve accurate cross-view feature point correspondence and provide basic data for 3D reconstruction. The 3D reconstruction sub-unit is used to dynamically generate a 3D mesh model of complex surfaces / cavities based on the matched feature point data and the crankcase's preset structural parameters. It obtains the dimensional data of complex parts through mesh node coordinate calculations, specifically including: 3D mesh generation employs the Delaunay triangulation algorithm to match the feature point set. (n is the number of feature points) Construct a 3D mesh model with a mesh cell side length ≤ 0.5mm to ensure model accuracy; For any two nodes in the mesh model The formula is Calculate the distance between two points ; For circular cavities such as crankshaft bores, select m feature points (m≥20) on the circumference and calculate the center of the fitted circle. With radius R, roundness error (i=1,2,...,m), where Let be the distance from the i-th feature point to the center of the circle; The reconstructed surface is compared with the preset theoretical surface model to calculate the profile error. (i=1,2,...,n) Let be the normal distance from the i-th feature point on the actual surface to the theoretical surface.

[0028] In this application, the feature point matching subunit uses a dynamic matching algorithm to adaptively adjust the feature point extraction threshold and matching weight according to the surface material characteristics (reflectivity, roughness) of the crankcase, thereby improving the feature matching accuracy of complex material surfaces.

[0029] In this application, the bottom surface of the cleaning limiting chamber is provided with an inclined guide surface, the lower end of which corresponds to the cleaning tank and is used to guide debris to collect in the cleaning tank; the inner side of the switch door 2 is provided with a sealing gasket to enhance the sealing of the detection support chamber.

[0030] In this application, the control module further includes an image preprocessing unit and a size calculation unit. The image preprocessing unit is used to denoise and enhance the images acquired by the vision camera 14. The size calculation unit is used to accurately calculate the planar dimensions and the dimensions of the three-dimensional reconstructed curved surface, and output the measurement results. Specifically, the image preprocessing unit uses a 3×3 window mid-range filtering algorithm to remove salt-and-pepper noise. The filtering formula is as follows: ,in These are the original image pixel values. The filtered pixel values ​​can quickly remove random noise and preserve the integrity of feature edges; the histogram equalization algorithm enhances image contrast and adjusts the gray level distribution range to 0-255, improving the detail recognition of low contrast areas (such as the inner wall of the cavity), laying the foundation for subsequent feature extraction. The size calculation unit extracts planar features (such as hole edges and contour lines) from the preprocessed image and converts them into actual dimensions using pixel coordinates. Based on the features such as hole edge and contour line extracted from the preprocessed image, the actual size is calculated according to the formula D=d×k, where d is the pixel distance, k=f / (s×q) is the pixel equivalent (f is the camera focal length, s is the pixel size, and q is the object distance), and k is calibrated by a calibration plate.

[0031] The working principle of this invention is to coordinate the vision measurement component, support component, supplementary lighting component 15, and auxiliary structure through a control module. Using non-contact vision measurement as the core, combined with mechanical positioning, adaptive supplementary lighting, and image processing technology, it achieves automated and precise measurement of crankcase plane and complex curved surface dimensions. Device initialization and baseline establishment After startup, the equipment first completes self-test and reset, with all moving components returning to their initial positions, and the supplementary lighting component 15 set to default illumination parameters. The control module drives the vision camera 14 to photograph the standard calibration board, acquiring the camera's optical and spatial position parameters to establish a unified equipment coordinate system, providing a reference for subsequent dimensional measurements. Simultaneously, the cooling fan 3 automatically starts and stops based on the temperature inside the measuring chamber 1, maintaining a stable operating environment for the equipment. The airflow guiding structure of the cleaning and limiting chamber and the limiting stage 4 are reset, preparing for workpiece clamping.

[0032] Workpiece positioning and adaptation adjustment The operator secures the crankcase using the adapter clamping assembly on the support plate 17, ensuring the workpiece reference surface is parallel to the measurement reference. The control module receives the target height command preset according to the crankcase specifications and transmits it to the cylinder 16 synchronous control module. Through flow regulation and position feedback compensation mechanisms, multiple cylinders 16 are driven to rise and fall synchronously, adjusting the crankcase to the detection height compatible with the vision camera 14, ensuring the distance between the camera and the detection surface meets the imaging requirements. After closing the switch door 2 of the measuring box body 1, the sealed structure isolates external stray light and dust, creating a stable environment for image acquisition.

[0033] Multi-view image acquisition and adaptive lighting The control module plans the motion path of the vision measurement component, drives the stepper motor 5 to rotate the rotating rod 6, the electric push cylinder 7 to control the extension and retraction of the sliding rod 8, the first drive motor 9 to adjust the height of the lifting platform 11 via the lead screw 10, and the second drive motor 12 to rotate the rotating block 13, so that the vision camera 14 can cover all inspection parts of the crankcase from multiple perspectives, including the top, side, and inside the cavity. The supplementary lighting component 15 works in real time with the vision camera 14, dynamically adjusting the light intensity and illumination angle by analyzing the clarity and reflectivity of the acquired images, eliminating shadows and overexposure, and ensuring that the images from each perspective can clearly present the details of the workpiece features.

[0034] Image processing and size calculation The multi-view images captured by the vision camera 14 are transmitted to the control module. First, the image preprocessing unit removes noise interference and enhances image contrast, highlighting key features such as hole edges and contour lines. Then, the coordinate calibration unit, combined with real-time motion parameters from the vision measurement component, corrects coordinate deviations in each viewpoint, ensuring all images are aligned based on the same coordinate system. The feature point matching unit extracts key feature points from each image and establishes corresponding relationships. The 3D reconstruction unit combines these feature points to construct a 3D mesh model of the crankcase, fully restoring the complex curved surface shape. The dimension calculation unit, based on the preprocessed planar images, converts planar dimensions using a pixel-to-actual-size calibration ratio. For the 3D mesh model, it calculates parameters such as the distance between two points on the surface, roundness, and contour, and compares them with preset tolerance ranges to determine if the dimensions are acceptable.

[0035] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A visual measurement device for crankcase dimensions, comprising: The measuring box body (1) is provided with a driving chamber, a detection support chamber and a cleaning limit chamber from top to bottom. The front sides of the measuring box body (1) are hinged with opening and closing doors (2) that cooperate with the driving chamber and the detection support chamber. Multiple cooling fans (3) that connect to the driving chamber are distributed longitudinally on both sides of the top surface. A cleaning groove that connects to the cleaning limit chamber is opened in the lower middle part of one side. A limit platform (4) is slidably assembled in the cleaning groove. A vision measurement component is assembled in the drive chamber and the detection support chamber to realize multi-dimensional image acquisition of the crankcase. A support assembly, assembled within the cleaning and limiting chamber, is used to support and position crankcases of different sizes. The control module is electrically connected to the vision measurement component, the support component, and the cooling fan (3) respectively. It is used to control the collaborative work of each component, receive the image information collected by the vision measurement component and perform size calculation. The control module integrates a multi-view image dynamic registration and surface reconstruction unit, which is used to calibrate the spatial coordinate deviation of each view image in real time and dynamically construct a three-dimensional model of the complex surface / cavity of the crankcase.

2. The crankcase dimension visual measurement device according to claim 1, characterized in that, The visual measurement component includes: A stepper motor (5) is vertically mounted in a groove on the bottom surface of the drive chamber, and its output shaft extends through the detection support chamber. The rotating rod (6) is mounted on the output shaft end of the stepper motor (5) and placed in the detection support chamber. The bottom surface is equipped with an electric push cylinder (7), and the inner cavity is provided with a sliding groove. The sliding rod (8) has an L-shaped cross-section and slides in cooperation with the sliding groove of the rotating rod (6). The sliding groove is vertically opened in the middle and the bottom surface is equipped with the first drive motor (9). The first drive motor (9) has an output shaft that passes through the bottom surface of the sliding rod (8) and extends into its sliding groove, and is connected to a lead screw (10) via a coupling. The lead screw (10) is placed in the sliding groove of the sliding rod (8), and the other end is rotatably connected to the top surface of the sliding groove; The lifting platform (11) slides in cooperation with the sliding groove of the sliding rod (8), and a threaded hole is provided on the other side of the top surface. It is threadedly connected to the lead screw (10) through the threaded hole, and a rotating groove is provided on one side of the top surface. The second drive motor (12) is mounted at the rear end of the rotating slot of the lifting platform (11), and its output shaft passes through the rotating slot. The rotating block (13) is rotatably mounted in the rotating slot of the lifting platform (11) and has a rotating hole. The output shaft of the second drive motor (12) passes through the rotating hole and is connected to the rotating block (13) for transmission. A visual camera (14) is mounted on one side of the rotating block (13); a supplementary lighting element (15) is mounted on the outer side below the visual camera (14) to provide auxiliary lighting for image acquisition.

3. The crankcase size visual measurement device according to claim 2, characterized in that, The supplementary lighting component (15) is an adjustable supplementary lighting lamp, including a light intensity adjustment module. The control module is electrically connected to the light intensity adjustment module and is used to dynamically adjust the luminous intensity and illumination angle of the supplementary lighting component (15) according to the reflective characteristics of the crankcase surface and the image clarity feedback.

4. The crankcase size visual measurement device according to claim 2, characterized in that, The sliding mating surface of the sliding rod (8) and the rotating rod (6) is provided with a guide protrusion, and the inner wall of the sliding groove of the rotating rod (6) is provided with a matching guide groove to limit the sliding direction of the sliding rod (8).

5. The crankcase dimension visual measurement device according to claim 1, characterized in that, The support components include: The support platform is fixed to the bottom surface of the cleaning and limiting chamber, has a conical cross-section, and has multiple limiting grooves evenly spaced on its top surface. Cylinders (16) are respectively assembled in multiple limiting slots of the support platform; support plate (17) is placed above cylinders (16), with its bottom surface fixed to the output shaft of multiple cylinders (16), and its top surface having multiple equally spaced fixing holes with different diameters, for adapting to external clamping and limiting components of different specifications.

6. The crankcase dimension visual measurement device according to claim 5, characterized in that, The cylinder (16) is equipped with a synchronization control module, which is electrically connected to the control module and is used to drive multiple cylinders (16) to extend and retract synchronously under the command of the control module, so as to ensure that the support plate (17) remains horizontally raised and lowered.

7. The crankcase size visual measurement device according to claim 1, characterized in that, The multi-view image dynamic registration and surface reconstruction unit of the control module includes: The coordinate calibration subunit is used to obtain the spatial position parameters of each visual camera (14) and correct the coordinate offset of images from different viewpoints in real time. The feature point matching subunit is used to extract feature points of the complex surface / cavity of the crankcase in images from various perspectives, and achieves accurate cross-view feature point correspondence through a preset dynamic matching algorithm. The 3D reconstruction sub-unit is used to dynamically generate a 3D mesh model of complex surfaces / cavities based on the matched feature point data and the preset structural parameters of the crankcase. The dimensional data of complex parts are obtained by calculating the coordinates of the mesh nodes.

8. The crankcase dimension visual measurement device according to claim 7, characterized in that, The feature point matching subunit employs a dynamic matching algorithm to adaptively adjust the feature point extraction threshold and matching weight based on the surface material characteristics of the crankcase.

9. The crankcase dimension visual measurement device according to claim 1, characterized in that, The bottom surface of the cleaning limiting chamber is provided with an inclined guide surface, the lower end of which corresponds to the cleaning tank and is used to guide debris to gather in the cleaning tank; the inner side of the switch door (2) is provided with a sealing gasket.

10. The crankcase dimension visual measurement device according to claim 1, characterized in that, The control module also includes an image preprocessing unit and a size calculation unit. The image preprocessing unit is used to denoise and enhance the images acquired by the vision camera (14). The size calculation unit is used to accurately calculate the planar dimensions and the dimensions of the three-dimensional reconstructed curved surface, and output the measurement results.

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