A device and method for detecting mis-installation and missing installation of shaft strings

Abstract

The present invention discloses a device and method for detecting mis-installation and missing installation of a shaft string in the field of mechanical manufacturing. The device comprises: a base, a light source, a projection screen, a camera and a processor. A groove for accommodating the central axis of the shaft string is provided on the top of the base. The light source is used to illuminate the shaft string and form a projection on the projection screen; the camera is used to collect the projection on the projection screen to generate a projection image; the processor is used to obtain the projection image and perform mis-installation and missing installation detection. The method comprises: irradiating the gears of the shaft string to be tested on the first / second reference line in turn by the light source to form a projection on the projection screen, and collecting the projection image by the camera; performing image processing on the projection image corresponding to each first / second reference line by the processor to obtain the corresponding projection thickness; comparing the projection thickness with the calibrated thickness, if the difference is greater than the error threshold, mis-installation or missing installation exists. The present invention can effectively improve the efficiency and accuracy of shaft string detection.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical manufacturing, and in particular to a device and method for detecting mis-installation and missing installation of a shaft string. Background Art

[0002] There are many types of gear shaft strings in automobile transmissions. During the production process, the assembled gear shaft strings need to be inspected to prevent problems such as incorrect installation or missing installation. Existing inspection methods often rely on manual observation and manual measurement, and both inspection efficiency and accuracy are difficult to guarantee. Summary of the Invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a device and method for detecting mis-installation and missing installation of a shaft string, so as to solve the technical problems of low detection efficiency and accuracy in traditional detection methods.

[0004] To achieve the above object, the present invention is implemented by adopting the following technical solutions:

[0005] In the first aspect, the present invention provides a device for detecting misinstallation and missing installation of a shaft string, wherein the shaft string includes a central shaft and a gear sleeved on the central shaft; the detection device includes a base, a light source, a projection screen, a camera and a processor, the top of the base is provided with a groove for accommodating the central shaft of the shaft string, the light source and the projection screen are respectively provided on both sides of the base, the light source is used to illuminate the shaft string and form a projection on the projection screen; the camera is provided on one side of the projection screen for collecting the projection on the projection screen to generate a projection image; the processor is electrically connected to the camera for acquiring the projection image and performing misinstallation and missing installation detection.

[0006] Optionally, the center line of the gears of the shaft string in the thickness direction is used as the first reference line, and the center line of the first reference line of the adjacent gears is used as the second reference line;

[0007] There are multiple light sources, each of which is correspondingly arranged on one of the first reference lines or the second reference line; or

[0008] There is one light source, which is arranged on a driving mechanism. The light source reaches the first reference line or the second reference line under the driving of the driving mechanism.

[0009] Optionally, the driving mechanism is an electric slide rail, and the electric slide rail has the same direction as the central axis of the shaft string.

[0010] In a second aspect, the present invention provides a method for detecting mis-installation and missing installation of a shaft string. Based on the above-mentioned detection device, the detection method includes:

[0011] The light source is used to sequentially illuminate the gears of the shaft string to be measured on the first reference line to form a projection on the projection screen, and the projection image is captured by a camera;

[0012] Performing image processing on the projection images corresponding to the first reference lines by a processor to obtain the projection thickness of the gears of the shaft strings corresponding to the first reference lines;

[0013] The light source is used to sequentially illuminate the center axis of the measured shaft string between adjacent gears on the second reference line to form a projection on the projection screen, and the projection image is captured by a camera;

[0014] Performing image processing on the projection images corresponding to the second reference lines by a processor to obtain the projection thickness of the central axis of the measured shaft string between adjacent gears corresponding to the second reference lines;

[0015] The projected thickness is compared with the calibrated thickness. If the difference is greater than an error threshold, there is a mis-installation or missing installation.

[0016] Optionally, the processor performing image processing on the projection image corresponding to the first reference line or the second reference line includes:

[0017] Preprocessing the projection image;

[0018] Extracting contour lines from the pre-processed projection image using an image edge detection algorithm to generate a contour line image;

[0019] Extracting horizontal lines from the contour line image using an image processing algorithm to generate a horizontal line image;

[0020] extracting the linear equation of each horizontal line from the horizontal line image by Hough transform;

[0021] The distance between the horizontal lines is calculated according to the linear equations of the horizontal lines to obtain the projected thickness.

[0022] Optionally, the preprocessing includes performing grayscale processing on the projection image.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The present invention provides a device and method for detecting mis- and missing shaft strings. By magnifying and projecting the shaft string and then capturing the projected image, the shaft string's dimensions are magnified, allowing image processing to be performed at a larger scale, facilitating detection and improving accuracy. Furthermore, through the unified control of the light source and camera by a processor, automated processing is achieved, improving detection efficiency and automation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 11 is a schematic structural diagram of a device for detecting mis-installation and missing installation of a shaft string provided by an embodiment of the present invention;

[0026] Figure 2 1 is a flow chart of a method for detecting mis-installation and missing installation of a shaft string provided by an embodiment of the present invention;

[0027] Figure 3 1 is a flow chart of an image processing process of a projection image provided by an embodiment of the present invention;

[0028] The following are marked in the figure:

[0029] 1. Shaft string; 11. Center axis; 12. Gear; 2. Base; 3. Light source; 4. Projection screen; 5. Camera; 6. Processor; 7. First baseline; 8. Second baseline. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0031] Example 1:

[0032] like Figure 1 As shown, an embodiment of the present invention provides a detection device for misinstallation and missing installation of a shaft string, wherein the shaft string 1 includes a central shaft 11 and a gear 12 sleeved on the central shaft 11; the detection device includes a base 2, a light source 3, a projection screen 4, a camera 5 and a processor 6. A groove for accommodating the central shaft 11 of the shaft string 1 is provided on the top of the base 2, the light source 3 and the projection screen 4 are respectively provided on both sides of the base 2, the light source 3 is used to illuminate the shaft string 1 and form a projection on the projection screen 4; the camera 5 is provided on one side of the projection screen 4 for collecting the projection on the projection screen 4 to generate a projection image; the processor 6 is electrically connected to the camera 5 for obtaining the projection image and performing misinstallation and missing installation detection.

[0033] Since the shaft string 1 generally includes multiple gears 12, if they are projected uniformly, interference will occur between the multiple gears 12, resulting in the inability to generate a complete projection image for each gear 12. Therefore, further settings are required: the center line of the gear 12 of the shaft string 1 in the thickness direction is used as the first reference line 7, and the center line of the first reference line 7 of the adjacent gear 12 is used as the second reference line 8.

[0034] On this basis, if multiple light sources 3 are provided, each light source 3 can be positioned on a corresponding first reference line 7 or second reference line 8; all light sources 3 can be electrically connected to the processor 6, and the processor 6 can sequentially activate the light sources 3 to achieve projection and acquisition at different positions. To facilitate subsequent image processing, each light source 3 should be located on the same straight line. If only one light source 3 is provided, it can be placed on a drive mechanism, which drives the light source 3 to the first reference line 7 or second reference line 8; the drive mechanism can be electrically connected to the processor 6, and the processor 6 controls the drive mechanism to drive the light source 3.

[0035] Specifically, in this embodiment, the driving mechanism is an electric slide rail, which is in the same direction as the central axis 11 of the shaft string 1. When the electric slide rail drives the light source 3 to move, it can ensure that the distance between the light source 3 and the central axis 11 remains unchanged and the light source 3 reaches the first reference line 7 or the second reference line 8. In other optional embodiments, other driving mechanisms can also be selected as needed.

[0036] This embodiment magnifies the shaft string 1 by projecting the central shaft 11 and the gear 12 in sections. Based on the magnified projection image, it is easier to detect accurately. At the same time, it realizes automatic operation based on the processor 6 to improve work efficiency.

[0037] Example 2:

[0038] Based on the detection device for mis-installation and missing installation of a shaft string provided in the first embodiment, the embodiment of the present invention further provides a detection method for mis-installation and missing installation of a shaft string, such as Figure 2 As shown, the detection method includes:

[0039] Step S1: Use a light source to sequentially illuminate the gears of the shaft string to be measured on a first reference line to form a projection on a projection screen, and use a camera to capture the projection image.

[0040] Step S2: performing image processing on the projection images corresponding to the first reference lines by a processor to obtain the projection thickness of the gears of the shaft strings corresponding to the first reference lines.

[0041] like Figure 1 As shown in the figure, when the positions of the light source, gear, and projection screen are fixed, the projected thickness of the gear is affected by the combined effect of the gear thickness and the gear diameter. Therefore, the gear thickness and gear diameter can be comprehensively judged by the projected thickness of the gear.

[0042] Step S3: Use a light source to sequentially illuminate the center axis of the measured shaft string between adjacent gears on the second reference line to form a projection on the projection screen, and use a camera to capture the projection image.

[0043] Step S4: performing image processing on the projection images corresponding to the second reference lines by a processor to obtain the projection thickness of the central axis of the measured shaft string between the adjacent gears corresponding to the second reference lines.

[0044] like Figure 1 As shown in the figure, when the positions of the light source, gears, and projection screen are fixed, the projected thickness of the central axis of the measured shaft string between adjacent gears is affected by the adjacent gear spacing and adjacent gear diameters. Therefore, the adjacent gear spacing and adjacent gear diameters can be comprehensively judged by the projected thickness of the central axis of the measured shaft string between adjacent gears.

[0045] Step S5: Compare the projected thickness with the calibrated thickness. If the difference is greater than the error threshold, there is misassembly or missing. The projected thickness of each gear is obtained through steps S1 and S2, and the projected distance between adjacent gears is obtained through steps S3 and S4, thus completing the inspection of all gears.

[0046] The calibrated thickness can be obtained by executing steps S1 to S4 on the standard shaft string.

[0047] In step 2 and step 4, the image processing process is the same, only the objects are different, such as Figure 3 As shown, the specific processor performs image processing on the projection image corresponding to the first reference line or the second reference line, including:

[0048] Step S10: pre-processing the projected image; the pre-processing includes grayscale processing of the projected image.

[0049] Step S20: extracting contour lines from the pre-processed projection image using an image edge detection algorithm to generate a contour line image.

[0050] If the projection image corresponding to the first reference line is processed, the contour line is the contour line of the gear.

[0051] If the projection image corresponding to the second reference line is processed, the contour lines are the center axes and contour lines between adjacent gears and the contour lines of the opposite surfaces of adjacent gears.

[0052] Step S30: extracting horizontal lines from the contour line image using an image processing algorithm to generate a horizontal line image.

[0053] Image processing algorithms, such as the OpenCV library, extract horizontal lines from contours and perform erosion, dilation, and minimum straight line length restrictions to optimize the extraction effect.

[0054] Step S40: extracting the linear equation of each horizontal line from the horizontal line image through Hough transform.

[0055] Step S50: Calculate the distance between the horizontal lines according to the linear equations of the horizontal lines to obtain the projection thickness.

[0056] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0057] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0058] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0059] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A device for detecting mis-installation and missing installation of a shaft string, wherein the shaft string comprises a central shaft and a gear sleeved on the central shaft; characterized in that: The detection device includes a base, a light source, a projection screen, a camera, and a processor. The top of the base is provided with a groove for accommodating the central axis of the shaft string. The light source and the projection screen are respectively provided on both sides of the base. The light source is used to illuminate the shaft string and form a projection on the projection screen. The camera is provided on one side of the projection screen and is used to capture the projection on the projection screen to generate a projection image. The processor is electrically connected to the camera and is used to obtain the projection image and perform mis-installation and missing installation detection. The center line of the gear of the shaft string in the thickness direction is used as the first reference line, and the center line of the first reference line of the adjacent gear is used as the second reference line; There are multiple light sources, each of which is correspondingly arranged on one of the first reference lines or the second reference line; or The light source is provided with one, and the light source is provided on a driving mechanism, and the light source reaches the first reference line or the second reference line under the driving of the driving mechanism; The detection method of the detection device includes: The light source is used to sequentially illuminate the gears of the shaft string to be measured on the first reference line to form a projection on the projection screen, and the projection image is captured by a camera; Performing image processing on the projection images corresponding to the first reference lines by a processor to obtain the projection thickness of the gears of the shaft strings corresponding to the first reference lines; The light source is used to sequentially illuminate the center axis of the measured shaft string between adjacent gears on the second reference line to form a projection on the projection screen, and the projection image is captured by a camera; Performing image processing on the projection images corresponding to the second reference lines by a processor to obtain the projection thickness of the central axis of the measured shaft string between adjacent gears corresponding to the second reference lines; The projected thickness is compared with the calibrated thickness. If the difference is greater than an error threshold, there is a mis-installation or missing installation.

2. The device for detecting mis-installation and missing installation of a shaft string according to claim 1, characterized in that: The driving mechanism is an electric slide rail, and the electric slide rail has the same direction as the central axis of the shaft string.

3. The device for detecting mis-installation and missing installation of shaft strings according to claim 1, characterized in that: The processor performing image processing on the projection image corresponding to the first reference line or the second reference line includes: Preprocessing the projection image; Extracting contour lines from the pre-processed projection image using an image edge detection algorithm to generate a contour line image; Extracting horizontal lines from the contour line image using an image processing algorithm to generate a horizontal line image; extracting the linear equation of each horizontal line from the horizontal line image by Hough transform; The distance between the horizontal lines is calculated according to the linear equations of the horizontal lines to obtain the projected thickness.

4. The device for detecting mis-installation and missing installation of a shaft string according to claim 3, characterized in that: The preprocessing includes performing grayscale processing on the projection image.

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