Automatic flatness detection device for mold processing

Abstract

An automatic flatness detection device for mold processing disclosed by the present invention comprises an operation table, an industrial camera and a visual processing module, the operation table comprises a table top, lifting foot stools are installed on both sides of the bottom of the table top, a rotating table is rotatably connected to the center of the table top, and a rotation driving module is installed at the bottom of the rotating table. An ambient light shielding bin is slidably connected to the outer side of the table top, the industrial camera is installed on the top wall of the ambient light shielding bin and is in communication connection with the visual processing module, and a light source assembly is installed on the inner wall of the ambient light shielding bin and comprises a servo guide rail moving module, an area light source and a light source controller. The light source controller is connected with the visual processing module and the area light source, and the ambient light shielding bin, the dynamic light source adjusting device and the rotating table are used for cooperative operation. For a complex curvature surface, multi-angle rotation of the rotary table and synchronous adjustment of a light source angle are realized, and the detection capability of the industrial camera on a complex-shape mold is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mold processing detection, and particularly relates to an automatic flatness detection device for mold processing. BACKGROUND

[0002] In the process of die casting, the die casting mold is the key equipment for the production of aluminum alloy die castings, and the flatness of the die surface plays a decisive role in the quality of the aluminum alloy die castings. If the flatness of the die surface is poor, it will lead to a series of serious problems such as size deviation, uneven wall thickness, surface defects, and difficult demolding of the aluminum alloy die castings, thereby greatly reducing the yield of the products.

[0003] At present, the die casting mold surface flatness detection covers multiple key items such as surface finish, surface defects, and flatness detection. In the field of detection technology, the mainstream detection methods include laser profilometer, dial gauge, three-coordinate measuring instrument, and CCD industrial camera. The laser profilometer obtains the surface profile information of the object by emitting a laser beam and measuring the reflected light, but its equipment cost is high, the detection process is relatively complex, and the professional skills of the operator are required. The dial gauge mainly relies on mechanical contact measurement, and the detection efficiency is low, and it can only measure a single point, so it is difficult to fully reflect the overall flatness of the die surface. Although the three-coordinate measuring instrument has high measurement accuracy, it has a large device size, high price, and slow detection speed, and is not suitable for large-scale and high-efficiency production detection scenes.

[0004] The CCD industrial camera has unique advantages in the detection of the flatness of the die casting mold surface. Its detection principle is to convert the optical image into an electrical signal by using a CCD image sensor, and then generate a digital image. In the detection process, the image information of the die surface is obtained by shooting the die surface, and then the image is analyzed by using an image processing algorithm to calculate the flatness, surface finish, and surface defect recognition parameters of the die surface. The CCD industrial camera can realize multi-item detection, the automatic detection process is simple, the detection accuracy is high, the detection result is intuitive and visual, the equipment cost is relatively low, the installation and debugging process is simple, and therefore it has been widely applied in actual production and processing.

[0005] However, due to their unique application scenarios and process requirements, die-casting molds often exhibit complex curvatures and strong reflective properties on their surfaces. This makes simple lighting adjustments and ambient light shielding measures ineffective when using CCD industrial cameras for inspection. The complex curvature of the mold surface leads to varying light reflection angles, resulting in uneven brightness and shadows in the images acquired by the camera, affecting the accurate assessment of the mold's surface condition. Furthermore, the strong reflective properties can easily cause image overexposure, resulting in the loss of crucial details. Under these circumstances, it is difficult to find a good balance between inspection efficiency and accuracy, failing to meet the ever-increasing demand for high-precision mold processing.

[0006] No effective solutions have yet been proposed to address the problems in the relevant technologies. Summary of the Invention

[0007] To achieve the above objectives, the present invention provides the following technical solution: an automatic flatness detection device for mold processing, comprising an operating table, an industrial camera, and a vision processing module. The operating table includes a tabletop, with lifting legs installed on both sides of the bottom of the tabletop. A rotating platform is rotatably connected to the center of the tabletop, and a rotation drive module is installed at the bottom of the rotating platform. An ambient light shielding chamber is slidably connected to the outer side of the tabletop. The industrial camera is installed on the top wall of the ambient light shielding chamber and is communicatively connected to the vision processing module. A light source assembly is installed on the inner wall of the ambient light shielding chamber. The light source assembly includes a servo guide rail moving module, a surface light source, and a light source controller. The light source controller is connected to the vision processing module and the surface light source, respectively. The industrial camera and the surface light source are each mounted on a slide table corresponding to the servo guide rail moving module.

[0008] As a preferred embodiment of the present invention, the light source controller includes a feedback control module. The feedback control module analyzes the grayscale distribution of images captured by an industrial camera, calculates the reflectivity of the mold surface, and generates adjustment commands for the surface light source based on a PID algorithm.

[0009] As a preferred technical solution of the present invention, the rotation drive module and the vision processing module are communicatively connected. The vision processing module calculates the edge sharpness or contrast of the image acquired by the industrial camera in real time. When the edge sharpness is lower than a set threshold, it generates a rotation control command for the rotary table.

[0010] As a preferred technical solution of the present invention, the rotation control command includes phased control logic: the first phase controls the rotary table to rotate at a first speed until the visual processing module detects that the edge sharpness reaches a preset range; the second phase controls the rotary table to rotate at a second speed, which is less than the first speed, until the edge sharpness reaches the maximum value.

[0011] As a preferred technical solution of the present invention, the vision processing module and the servo guide rail moving module are communicatively connected. The vision processing module calculates the edge sharpness or contrast of the image acquired by the industrial camera in real time. When the edge sharpness is lower than a set threshold, it generates a lifting control command for the surface light source.

[0012] This is a preferred technical solution of the present invention.

[0013] As a preferred embodiment of the present invention, the surface light source is an LED light source, which is distributed circumferentially around the lens of the industrial camera.

[0014] As a preferred embodiment of the present invention, the inner wall of the ambient light shielding chamber is coated with a light-absorbing coating, one end of the ambient light shielding chamber is provided with an inlet and outlet, and a door panel is installed at the inlet and outlet of the ambient light shielding chamber.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] This invention addresses the complex curvature and strong reflective characteristics of die-casting molds. By dynamically adjusting the height and brightness of a surface light source based on the grayscale distribution of industrial camera images, it precisely handles the reflective issues of complex curved surfaces, improving the accuracy of mold surface detail detection and enabling the identification of micron-level defects. Based on the edge sharpness or contrast of the images captured by the industrial camera, control commands are generated for the rotating stage and light source, achieving accurate measurement of mold flatness and avoiding quality misjudgments. Each frame of the industrial camera image triggers feedback adjustment, forming a real-time closed loop of "capture → analysis → adjustment → re-capture," promptly adjusting detection parameters, reducing unnecessary operations, and meeting the rapid inspection needs of large-scale production. It utilizes an ambient light shielding chamber, dynamic light source adjustment, and a rotating stage working in tandem. For complex curved surfaces, the rotating stage rotates at multiple angles, synchronously adjusting the light source angle to eliminate blind spots and enhance the industrial camera's ability to inspect molds with complex shapes. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0018] Fig. 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Fig. 2 This is a schematic diagram of the internal structure of the ambient light shielding chamber in this invention;

[0020] Fig. 3 This is the overall process in this invention;

[0021] In the diagram: 1. Tabletop; 2. Lifting stand; 3. Rotary table; 4. Ambient light shielding chamber; 5. Vision processing module; 6. Servo guide rail moving module; 7. Industrial camera; 8. Surface light source; 9. Light source controller; 10. Entrance / exit; 11. Door panel; 12. Rotation drive module. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example

[0024] Please see Figs. 1-3 The present invention provides the following technical solution: an automatic flatness detection device for mold processing, comprising an operating table, an industrial camera 7, and a vision processing module 5. The operating table includes a table surface 1, with lifting legs 2 installed on both sides of the bottom of the table surface 1. A rotating table 3 is rotatably connected to the center of the table surface 1, and a rotation drive module 12 is installed at the bottom of the rotating table 3. An ambient light shielding chamber 4 is slidably connected to the outer side of the table surface 1. The industrial camera 7 is installed on the top wall of the ambient light shielding chamber 4. The industrial camera 7 and the vision processing module 5 are communicatively connected. A light source assembly is installed on the inner wall of the ambient light shielding chamber 4. The light source assembly includes a servo guide rail moving module 6, a surface light source 8, and a light source controller 9. The light source controller 9 is connected to the vision processing module 5 and the surface light source 8 respectively. The industrial camera 7 and the surface light source 8 are each mounted on a slide table corresponding to the servo guide rail moving module 6 on one side.

[0025] In order to precisely adjust the light source to adapt to the complex reflective characteristics of the mold and improve the image acquisition quality to ensure detection accuracy, in this embodiment, as a preferred technical solution of the present invention, the light source controller 9 includes a feedback control module. The feedback control module analyzes the grayscale distribution of the image captured by the industrial camera 7, calculates the reflective intensity of the mold surface, and generates adjustment instructions for the surface light source 8 based on the PID algorithm.

[0026] To ensure that the rotary table 3 can dynamically adjust its rotation state according to the surface condition of the mold and improve the comprehensiveness and accuracy of the inspection, in this embodiment, as a preferred technical solution of the present invention, the rotation drive module 12 and the vision processing module 5 are connected in communication. The vision processing module 5 calculates the edge sharpness or contrast of the image acquired by the industrial camera 7 in real time. When the edge sharpness is lower than the set threshold, it generates a rotation control command for the rotary table 3.

[0027] In order to achieve high-precision detection of key areas on the mold surface while ensuring detection efficiency, and to balance detection speed and accuracy, in this embodiment, as a preferred technical solution of the present invention, the rotation control command includes phased control logic: the first phase controls the rotary table 3 to rotate at a first speed until the vision processing module 5 detects that the edge sharpness reaches a preset range; the second phase controls the rotary table 3 to rotate at a second speed, which is less than the first speed, until the edge sharpness reaches the maximum value.

[0028] In order to improve the lighting effect on the mold surface and enhance the clarity and accuracy of the image by adjusting the height of the surface light source in real time, in this embodiment, as a preferred technical solution of the present invention, the vision processing module 5 and the servo guide rail moving module 6 are connected in communication. The vision processing module 5 calculates the edge sharpness or contrast of the image captured by the industrial camera 7 in real time. When the edge sharpness is lower than the set threshold, it generates a lifting control command for the surface light source 8.

[0029] In order to provide uniform and stable ambient lighting and reduce the detection error caused by uneven lighting on the mold surface, in this embodiment, as a preferred technical solution of the present invention, the surface light source 8 is an LED light source, which is distributed circumferentially around the lens of the industrial camera 7.

[0030] In order to minimize the interference of ambient light on the detection process and create a stable detection environment, in this embodiment, as a preferred technical solution of the present invention, the inner wall of the ambient light shielding chamber 4 is coated with a light-absorbing coating, and an inlet / outlet 10 is provided at one end of the ambient light shielding chamber 4. A door panel 11 is installed at the inlet / outlet 10 of the ambient light shielding chamber 4.

[0031] In summary, by utilizing the above-described technical solution of the present invention,

[0032] Ambient light shielding chamber 4: Constructs a sealed detection space, effectively eliminating external light interference and providing a stable environment for detection. Industrial camera 7: Responsible for acquiring images of the mold surface, providing a data foundation for subsequent analysis. Vision processing module 5: Performs feature analysis on the images acquired by industrial camera 7 and generates control commands based on the analysis results, guiding the dynamic adjustment of the entire detection process. Light source assembly: Consists of servo guide rail movement module 6, surface light source 8, and light source controller 9, which can dynamically adjust illumination parameters according to detection requirements and optimize the illumination conditions of the mold surface. Rotary stage 3: Used to support the mold and, through staged rotation, works with industrial camera 7 to achieve multi-angle detection, comprehensively acquiring information about the mold surface.

[0033] Work process and principles

[0034] Step 1: Mold Placement and Environment Initialization

[0035] Mold Fixing: The mold to be tested is precisely placed at the center of the rotary table 3. The ambient light shielding chamber 4 then closes via a sliding mechanism, and the door panel 11 seals the inlet and outlet 10 to ensure the airtightness of the testing environment. The inner wall of the ambient light shielding chamber 4 is coated with a light-absorbing coating, such as matte black paint, to absorb stray light and reduce light reflection interference. Simultaneously, the height of the tabletop 1 is adjusted using the lifting legs 2 to a height convenient for the operator.

[0036] Step 2: Initial Light Source and Camera Positioning

[0037] Light source pre-adjustment: The surface light source 8 is moved to the initial set position (e.g., 300mm from the mold surface) by means of the servo guide rail moving module 6. In addition, the surface light source 8 provides uniform basic illumination, initially illuminating the mold surface.

[0038] Camera focusing: Industrial camera 7 captures an initial image, and vision processing module 5 calculates the image sharpness. If the sharpness does not meet the standard, the system will fine-tune the camera focus or the position of the light source until the image is sharp.

[0039] Step 3: Closed-loop detection and dynamic adjustment

[0040] (1) Image acquisition and feature analysis

[0041] A-Image Acquisition: Industrial camera 7 continuously captures images of the mold surface and transmits the image data to vision processing module 5 in real time.

[0042] B-feature extraction:

[0043] Gray-scale distribution analysis: By calculating the overall gray-scale mean and standard deviation of the image, the reflectivity of the mold surface is evaluated. For example, a gray-scale value > 200 is considered overexposed.

[0044] Edge sharpness calculation: Using the Canny edge detection algorithm, the edge sharpness of the mold surface is quantified to determine the surface flatness.

[0045] Contrast evaluation: Using the Michelson contrast formula method, the difference between bright and dark areas of the image is statistically analyzed to help evaluate the surface condition of the mold.

[0046] (2) Dynamic adjustment of light source:

[0047] Feedback control logic: When the vision processing module 5 detects that the gray value of a certain area is too strong and exceeds the set standard, the light source controller 9 is immediately triggered.

[0048] PID algorithm tuning:

[0049] Proportional term P: Calculates the light source displacement based on the current grayscale deviation. For example, if the grayscale exceeds the threshold by 10%, the light source height is reduced by 5mm.

[0050] Integral Term I: Accumulates historical deviations to eliminate persistent overexposure issues. For example, if three consecutive frames are overexposed, the light source angle is reduced by 2°.

[0051] Differential term D: Predicts grayscale change trends and adjusts light source parameters in advance. For example, if the grayscale change rate accelerates, the light source brightness decreases by 15%.

[0052] Actions performed: The vision processing module 5 drives the servo guide rail movement module 6 to adjust the height of the surface light source 8, and the light source controller 9 precisely adjusts the brightness of the surface light source 8.

[0053] Example scenario: When the image is overexposed due to reflections at the edge of the mold, the system adjusts the light source to move down by 10mm. After reshooting, the grayscale standard deviation drops from 45 to 18, effectively improving image quality.

[0054] (3) Three-stage control of the rotary table

[0055] The first stage is coarse adjustment: the rotary table 3 rotates at a relatively high speed, such as 5 r / min, and the industrial camera 7 quickly scans the mold surface at a lower resolution to locate suspected defect areas. The vision processing module 5 calculates the edge sharpness in real time. When the sharpness value enters the preset range, the inspection process enters the second stage.

[0056] The second stage of fine-tuning involves switching the rotary stage 3 to a low speed, such as 0.5 r / min, and the industrial camera 7 to high-resolution mode to perform detailed imaging of the target area. If the edge sharpness does not reach its maximum value, the rotary stage 3 rotates in the opposite direction by 0.1° and reshoots until the sharpness peak is locked.

[0057] Closed-loop feedback optimization

[0058] Real-time performance: The industrial camera 7 triggers a feedback adjustment mechanism for each frame it captures, forming a real-time closed loop of "capture → analysis → adjustment → re-capture" to optimize detection parameters in a timely manner.

[0059] Adaptive parameters: PID algorithm parameters such as integral time Ti are dynamically adjusted according to different mold materials.

[0060] Finally, it should be noted that, in this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0061] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An automatic flatness detection device for mold processing, comprising an operating table, an industrial camera (7), and a vision processing module (5), characterized in that: The operating table includes a tabletop (1), with lifting legs (2) installed on both sides of the bottom of the tabletop (1). A rotating platform (3) is rotatably connected to the center of the tabletop (1). A rotating drive module (12) is installed at the bottom of the rotating platform (3). An ambient light shielding chamber (4) is slidably connected to the outer side of the tabletop (1). An industrial camera (7) is installed on the top wall of the ambient light shielding chamber (4). The industrial camera (7) is communicatively connected to the vision processing module (5). A light source assembly is installed on the inner wall of the ambient light shielding chamber (4). The light source assembly includes a servo guide rail moving module (6), a surface light source (8), and a light source controller (9). The light source controller (9) is connected to the vision processing module (5) and the surface light source (8) respectively. The industrial camera (7) and the surface light source (8) are each mounted on a slide of the corresponding servo guide rail moving module (6) on one side.

2. The automatic flatness detection device for mold processing according to claim 1, characterized in that: The light source controller (9) includes a feedback control module, which calculates the reflectivity of the mold surface by analyzing the grayscale distribution of the image captured by the industrial camera (7), and generates adjustment instructions for the surface light source (8) based on the PID algorithm.

3. The automatic flatness detection device for mold processing according to claim 2, characterized in that: The rotation drive module (12) and the vision processing module (5) are connected in communication. The vision processing module (5) calculates the edge sharpness or contrast of the image acquired by the industrial camera (7) in real time. When the edge sharpness is lower than the set threshold, it generates a rotation control command for the rotary table (3).

4. The automatic flatness detection device for mold processing according to claim 3, characterized in that: The rotation control command includes phased control logic: in the first phase, the rotary table (3) is controlled to rotate at a first speed until the visual processing module (5) detects that the edge sharpness reaches a preset range; in the second phase, the rotary table (3) is controlled to rotate at a second speed, which is less than the first speed, until the edge sharpness reaches the maximum value.

5. The automatic flatness detection device for mold processing according to claim 1, characterized in that: The vision processing module (5) and the servo guide rail moving module (6) are connected in communication. The vision processing module (5) calculates the edge sharpness or contrast of the image acquired by the industrial camera (7) in real time. When the edge sharpness is lower than the set threshold, it generates a lifting control command for the surface light source (8).

6. The automatic flatness detection device for mold processing according to claim 5, characterized in that: The surface light source (8) is an LED light source, which is distributed circumferentially around the lens of the industrial camera (7).

7. The automatic flatness detection device for mold processing according to claim 1, characterized in that: The inner wall of the ambient light shielding chamber (4) is coated with a light-absorbing coating. One end of the ambient light shielding chamber (4) is provided with an inlet and outlet (10). A door panel (11) is installed at the inlet and outlet (10) of the ambient light shielding chamber (4).

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