A steel wire rope diameter measuring device and method based on visual displacement compensation

Abstract

This invention provides a device and method for measuring the diameter of a steel wire rope based on visual displacement compensation, relating to the field of steel wire rope diameter measurement technology. It includes an installation mechanism sleeved on the steel wire rope and vibrating synchronously with it; at least three industrial cameras arranged in a circumferential array around the steel wire rope on the installation mechanism; an image preprocessing module connected to the industrial cameras and performing noise reduction and grayscale conversion on the acquired images; an edge detection module connected to the preprocessing module and acquiring edge images of the steel wire rope from the preprocessed images; a processing module connected to the edge detection module that converts the edge images into straight lines in the actual spatial coordinate system, calculates the displacement compensation amount caused by the vibration or offset of the steel wire rope relative to the installation mechanism, and calculates the steel wire rope diameter; and a control and display module. This invention effectively compensates for the displacement caused by vibration or offset of the steel wire rope when measuring its diameter, achieving high-precision, non-contact diameter measurement without damaging the surface of the steel wire rope.

Description

Technical Field

[0001] This invention relates to the field of wire rope diameter measurement technology, specifically to a wire rope diameter measurement device and method based on visual displacement compensation. Background Technology

[0002] In industrial production, wire ropes serve as crucial load-bearing and transmission components, and accurate diameter measurement is essential for ensuring safe equipment operation and product quality. However, in actual measurement processes, wire ropes often experience vibration or deviation due to various factors, which greatly complicates diameter measurement.

[0003] In existing technologies, some traditional measurement methods, such as mechanical methods, are used to address the inaccuracy caused by wire rope vibration or misalignment. These methods obtain diameter data through direct contact with the wire rope. However, these methods have significant drawbacks: mechanical measuring devices are easily affected by the surface condition of the wire rope during contact, such as oil or rust, which can lead to inaccurate measurements. Furthermore, mechanical contact can damage the wire rope surface, affecting its service life. Moreover, traditional methods struggle to compensate for measurement errors caused by wire rope vibration or misalignment in real time and dynamically, failing to meet the demands for high-precision and high-efficiency measurements. Summary of the Invention

[0004] To address the above problems, this invention provides a wire rope diameter measuring device and method based on visual displacement compensation.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a wire rope diameter measuring device and method based on visual displacement compensation, comprising an installation mechanism sleeved on the wire rope and vibrating synchronously with the wire rope, at least three industrial cameras arranged in a circumferential array on the installation mechanism about the wire rope, an image preprocessing module connected to the industrial cameras and performing noise reduction and grayscale processing on the acquired images, an edge detection module connected to the preprocessing module and obtaining the edge image of the wire rope through the preprocessed image, a processing module connected to the edge detection module and converting the edge image into a straight line in the actual spatial coordinate system, calculating the displacement compensation amount caused by the vibration or vibration of the wire rope relative to the installation mechanism and calculating the wire rope diameter, and a control and display module;

[0006] The mounting mechanism includes two measuring blocks fitted onto a steel wire rope by having measuring grooves opened on opposite sides, two sets of symmetrical locking components that are engaged with the steel wire rope and respectively set above and below the two measuring blocks, and a mounting component that fixes the two measuring blocks in the position along the length of the steel wire rope. Multiple industrial cameras are mounted in a circular array on the inner wall of the measuring groove.

[0007] Preferably, the limiting component includes two positioning posts respectively mounted on the same end of the two measuring blocks via connecting rods, a rotating ring rotatably disposed on the side of the positioning posts and having an annular groove on the side that matches the side of the wire rope, and a magnetic component disposed inside the positioning posts.

[0008] Preferably, one end of the positioning post has an adjustment groove. The magnetic component includes multiple adjustment magnets arranged in a circumferential array along the axial direction of the adjustment groove, an adjustment screw threaded between the multiple adjustment magnets, a positioning ring threaded through the center of the opening of the adjustment groove and sleeved on the adjustment screw, multiple positioning slide rods vertically arranged on the side of the positioning ring and with adjustment sliders slidably sleeved on their rods, an adjustment disc threadedly sleeved on the adjustment screw and located between the multiple adjustment sliders, and multiple linkage rods with one end rotatably connected to different adjustment sliders and the other end rotatably connected to the side of the adjustment disc. The adjustment screw is driven by an adjustment motor installed on the end of the positioning post, and the adjustment motor is installed on the positioning post by a mounting block.

[0009] Preferably, the mounting assembly includes connecting rods symmetrically mounted in pairs on the side of each measuring block, a buffer block mounted below the overlapping ends of the two connecting rods, a buffer disc fitted onto the buffer block through a buffer groove on its top end face, and a mounting bracket connecting the two buffer discs. Multiple positioning springs are arranged in a circumferential array inside the buffer groove, and each positioning spring is connected at both ends to the wall of the buffer groove and the side of the buffer block, respectively. When the two measuring blocks are mounted on the wire rope, the ends of the two connecting rods located on the same side of the two measuring blocks overlap.

[0010] Preferably, the edge detection module uses an improved Kalman filter to smooth the preprocessed image, then calculates the gradient magnitude and gradient direction of the smoothed image by taking partial derivatives, performs maximum suppression based on the gradient magnitude and direction, and finally uses the Otsu algorithm based on binary search to calculate the high threshold and low threshold, and obtains the wire rope edge image based on the threshold comparison.

[0011] The improved Kalman filtering method constructs a two-dimensional fractional-order stochastic discrete space state model, and based on this model, obtains a two-dimensional discrete Kalman filtering algorithm for smoothing images.

[0012] Preferably, when processing the edge image of the wire rope, the processing module sequentially performs Hough transform on the edge image to obtain the target straight line of the wire rope in the image, and converts the target straight line in the image coordinate system into a straight line in the actual spatial coordinate system according to the calibration parameters of the industrial camera, and calculates the displacement compensation amount caused by the vibration or offset of the wire rope, and then calculates the diameter of the wire rope based on the compensated target straight line and the calibration relationship between the pixel size of the wire rope in the image and the actual size.

[0013] Preferably, in the processing module, the calibration parameters of the industrial camera include internal parameters and external parameters, which are obtained by calibrating the industrial camera using a calibration board. The internal parameters include focal length and principal point coordinates, while the external parameters include the camera's position and orientation.

[0014] A method for measuring the diameter of a steel wire rope based on visual displacement compensation includes the following steps:

[0015] Step 1: Use at least three industrial cameras to capture images of the steel wire rope from different angles;

[0016] Step 2: Denoise and convert the acquired image to grayscale;

[0017] Step 3: The preprocessed image is smoothed using an improved Kalman filter method. Then, the gradient magnitude and direction of the smoothed image are calculated by taking partial derivatives. Maximum suppression is performed based on the gradient magnitude and direction. Finally, the Otsu algorithm based on binary search is used to calculate the high and low thresholds. The edge image of the wire rope is obtained by comparing the thresholds.

[0018] Step 4: Perform Hough transform on the edge image to obtain the target straight line of the steel wire rope in the image;

[0019] Step 5: Based on the calibration parameters of the industrial camera, convert the target straight line in the image coordinate system into a straight line in the actual spatial coordinate system, and calculate the displacement compensation caused by the vibration or offset of the wire rope.

[0020] Step 6: Based on the compensated target straight line, and combined with the calibration relationship between the pixel size of the wire rope in the image and its actual size, calculate the diameter of the wire rope;

[0021] Step 7: Display the measured wire rope diameter on the control and display module.

[0022] Preferably, in step one, the shooting frequency of the industrial camera is adjusted according to the running speed of the wire rope to ensure that clear images of the wire rope are captured.

[0023] Preferably, in step seven, the measured wire rope diameter data is stored in the data storage unit.

[0024] The beneficial effects of this invention are:

[0025] 1. By acquiring wire rope images from different angles using at least three industrial cameras, and combining improved edge detection algorithms and precise calculations by the processing module, the edge information of the wire rope can be accurately obtained, and the displacement caused by wire rope vibration or offset can be effectively compensated, greatly improving the accuracy of wire rope diameter measurement.

[0026] 2. The vision-based measurement method eliminates the need for direct contact with the wire rope, avoiding measurement errors and damage to the wire rope surface caused by contact in traditional mechanical measurement methods, thus extending the service life of the wire rope.

[0027] 3. The processing module can calculate the displacement compensation amount in real time based on the vibration or offset of the wire rope and adjust the measurement results in a timely manner, realizing real-time and dynamic measurement of the wire rope diameter, which meets the needs of high-efficiency measurement in industrial production.

[0028] 4. The limit components and installation components of the installation mechanism are reasonably designed, which can adapt to the measurement needs of steel wire ropes of different specifications, and can maintain good measurement stability under different working conditions.

[0029] 5. The measured wire rope diameter data can be stored in the data storage unit for easy retrieval and analysis later; at the same time, the measurement results can be displayed in real time through the control and display module, so that operators can understand the wire rope diameter in a timely manner and ensure production safety. Attached Figure Description

[0030] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0031] Figure 1 This is a simplified structural diagram of the wire rope diameter measuring device based on visual displacement compensation proposed in this invention.

[0032] Figure 2 This is a schematic diagram of the unfolded structure of the wire rope diameter measuring device based on visual displacement compensation proposed in this invention.

[0033] Figure 3 This is a schematic diagram of the buffer disk and buffer block structure of the present invention.

[0034] Figure 4 This is a schematic diagram of the limiting component structure of the present invention.

[0035] Figure 5 This is a schematic diagram of the cross-sectional structure of the limiting component of the present invention.

[0036] Figure 6 This is a schematic diagram of the internal structure of the limiting component of the present invention.

[0037] In the diagram: 1. Measuring block; 2. Measuring groove; 3. Connecting rod; 4. Positioning column; 5. Rotating ring; 6. Mounting block; 7. Adjusting motor; 8. Connecting rod; 9. Buffer plate; 10. Buffer groove; 11. Buffer block; 12. Positioning spring; 13. Mounting bracket; 14. Lighting groove; 15. Light strip; 16. Acquisition groove; 17. Industrial camera; 18. Adjustment groove; 19. Adjusting screw; 20. Positioning ring; 21. Positioning slide rod; 22. Adjusting slider; 23. Linkage rod; 24. Adjusting plate; 25. Adjusting magnet. Detailed Implementation

[0038] To make the technical means, creative features, achieved objectives, and effects of this invention readily understandable, the invention is further described below with reference to specific embodiments and accompanying drawings. However, the following embodiments are merely preferred embodiments of this invention and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments described herein without creative effort are all within the protection scope of this invention.

[0039] Example 1: Reference Figures 1-6 The device and method for measuring the diameter of a steel wire rope based on visual displacement compensation include an installation mechanism that is sleeved on the steel wire rope and vibrates synchronously with the steel wire rope; at least three industrial cameras 17 arranged in a circumferential array on the installation mechanism about the steel wire rope; an image preprocessing module connected to the industrial cameras 17 and performing noise reduction and grayscale processing on the acquired images; an edge detection module connected to the preprocessing module and obtaining the edge image of the steel wire rope through the preprocessed image; a processing module connected to the edge detection module that converts the edge image into a straight line in the actual spatial coordinate system, calculates the displacement compensation amount caused by the vibration or vibration of the steel wire rope relative to the installation mechanism, and calculates the diameter of the steel wire rope; and a control and display module.

[0040] The edge detection module uses an improved Kalman filter to smooth the preprocessed image, then calculates the gradient magnitude and direction of the smoothed image by taking partial derivatives, performs maximum suppression based on the gradient magnitude and direction, and finally uses the Otsu algorithm based on binary search to calculate the high and low thresholds, and obtains the wire rope edge image by comparing the thresholds.

[0041] The improved Kalman filtering method constructs a two-dimensional fractional-order stochastic discrete space state model, and based on this model, obtains a two-dimensional discrete Kalman filtering algorithm for smoothing images.

[0042] When processing the edge image of the wire rope, the processing module performs Hough transform on the edge image in sequence to obtain the target straight line of the wire rope in the image. Based on the calibration parameters of the industrial camera, the target straight line in the image coordinate system is converted into a straight line in the actual spatial coordinate system. The displacement compensation amount caused by the vibration or offset of the wire rope is calculated. Then, based on the compensated target straight line and the calibration relationship between the pixel size of the wire rope in the image and its actual size, the diameter of the wire rope is calculated.

[0043] In the processing module, the calibration parameters of the industrial camera include internal parameters and external parameters, which are obtained by calibrating the industrial camera using a calibration board. The internal parameters include focal length and principal point coordinates, while the external parameters include the camera's position and orientation.

[0044] The mounting mechanism includes two measuring blocks 1 fitted onto a steel wire rope by having measuring grooves 2 opened on opposite sides, two sets of limiting components symmetrically engaged with the steel wire rope and respectively set above and below the two measuring blocks 1, and mounting components for fixing the two measuring blocks 1 in the position along the length of the steel wire rope. Multiple industrial cameras 17 are mounted in a circular array on the inner wall of the measuring groove 2.

[0045] In this embodiment, two measuring blocks 1 are combined and fitted onto the wire rope through measuring grooves 2 opened on opposite sides. Two sets of symmetrical limiting components are respectively engaged with the wire rope and located above and below the two measuring blocks 1. These limiting components stabilize the position of the wire rope within the measuring blocks, preventing significant shaking or displacement during measurement. Simultaneously, mounting components fix the positions of the two measuring blocks 1 along the length of the wire rope, ensuring the entire mounting mechanism is securely fitted onto the wire rope and can vibrate synchronously with it, providing a stable foundation for subsequent accurate image acquisition. At least three industrial cameras 17 are mounted in a circular array on the inner wall of the measuring groove 2 (specifically, the industrial cameras 17 are installed within the acquisition grooves 16 opened in the wall of the measuring groove 2). They simultaneously acquire images of the wire rope from different angles. This multi-angle arrangement of the industrial cameras 17 allows for comprehensive acquisition of the wire rope's appearance information, avoiding blind spots caused by a single viewpoint, improving the completeness and accuracy of image acquisition, and providing rich data support for subsequent precise measurement of the wire rope diameter. The image preprocessing module is connected to the industrial camera 17 and performs denoising and grayscale processing on the acquired images. Denoising eliminates noise caused by environmental interference and equipment factors, making the image clearer. Grayscale processing converts the color image to grayscale, reducing the image data size while highlighting edge and contour information, facilitating subsequent edge detection and improving processing efficiency and accuracy. The edge detection module is connected to the image preprocessing module and uses an improved Kalman filter to smooth the preprocessed image, further removing noise and interference for a smoother image. Next, it calculates the gradient magnitude and direction of the smoothed image using partial derivatives, performs maximum suppression based on the gradient magnitude and direction to remove non-edge points and retain true edge points. Finally, it uses the Otsu algorithm based on binary search to calculate high and low thresholds, and obtains the wire rope edge image based on threshold comparison. Through this series of complex edge detection algorithms, the edge information of the wire rope can be accurately and clearly extracted, providing crucial information for subsequent calculation of the wire rope diameter. The processing module, connected to the edge detection module, first performs a Hough transform on the edge image to obtain the target straight line of the wire rope in the image. Then, based on the calibration parameters of the industrial camera, it converts the target straight line in the image coordinate system into a straight line in the actual spatial coordinate system and calculates the displacement compensation amount caused by wire rope vibration or offset to correct the target straight line, eliminating the influence of wire rope jitter or offset on the measurement results. Finally, based on the compensated target straight line and the calibration relationship between the pixel size of the wire rope in the image and its actual size, the diameter of the wire rope is calculated. Through this precise displacement compensation and diameter calculation method, accurate and reliable wire rope diameter data can be obtained.The control and display module is connected to the processing module to display the measured wire rope diameter, allowing operators to monitor the wire rope diameter in real time. Simultaneously, operators can use the control module to operate and configure the entire measuring device, such as adjusting industrial camera parameters, starting or stopping measurements, thus achieving flexible control over the measurement process.

[0046] This embodiment of the wire rope diameter measurement device and method based on visual displacement compensation ensures synchronous vibration with the wire rope through a reasonable installation mechanism design. It uses a multi-angle industrial camera 17 to comprehensively acquire images, and after a series of precise image processing and calculations, it can effectively compensate for errors caused by wire rope vibration or offset, achieving high-precision, non-contact wire rope diameter measurement. The measurement results are displayed and controlled in real time, providing strong support for the quality inspection and safety assurance of wire ropes in industrial production.

[0047] like Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the limiting assembly includes two positioning posts 4 respectively installed on the same end of two measuring blocks 1 via connecting rods 3, a rotating ring 5 rotatably disposed on the side of the positioning post 4 and having an annular groove on the side that matches the side of the wire rope, and a magnetic component disposed inside the positioning post 4.

[0048] In this embodiment, when two measuring blocks 1 are combined and fitted onto the wire rope through the measuring grooves 2 on their opposing surfaces, the two positioning posts 4 of the limiting component are respectively installed on the same end of the two measuring blocks 1 via connecting rods 3, and the positioning posts 4 are also in place. The positioning posts 4 provide a basic support structure for the subsequent installation of the rotating ring 5 and the realization of the limiting function, ensuring that the entire limiting component can stably cooperate with the measuring blocks 1. The rotating ring 5 is rotatably set on the side of the positioning post 4, and its side has an annular groove that matches the side of the wire rope. When the measuring block 1 is fitted onto the wire rope, the rotating ring 5 fits tightly against the side of the wire rope through its annular groove. This fitting design allows the rotating ring 5 to rotate flexibly with the slight movement of the wire rope, without excessively hindering the normal movement of the wire rope, and ensuring that the position of the wire rope is constrained to a certain extent, preventing the wire rope from swaying or deviating significantly from its original position during measurement. The magnetic component set in the positioning post 4 plays a role, generating a certain magnetic force. This magnetic force attracts the steel wire rope (which is made of magnetic material), further enhancing the fixing effect of the limiting component on the steel wire rope. Even if the steel wire rope is disturbed by external factors and tends to shake or move, the magnetic force of the magnetic component can pull the steel wire rope back to its original position as much as possible (or shake or move synchronously with the steel wire rope), ensuring the relative position of the steel wire rope within the measuring block 1 is stable, thus providing good conditions for subsequent accurate measurement of the steel wire rope diameter.

[0049] In this embodiment, the positioning post 4 is used to connect and position the measuring block 1. The rotating ring 5 uses its annular groove that matches the wire rope to allow the wire rope to move slightly while limiting its large sway. The magnetic component enhances the fixing effect of the wire rope through magnetic force. The three work together to effectively ensure the positional stability of the wire rope during the measurement process and improve the accuracy and reliability of the wire rope diameter measurement.

[0050] like Figures 4-6 As shown, the positioning post 4 has an adjustment groove 18 at one end. The magnetic components include multiple adjustment magnets 25 arranged in a circumferential array along the axial direction of the adjustment groove 18, an adjustment screw 19 passing through the multiple adjustment magnets 25, a positioning ring 20 passing through the middle of the opening of the adjustment groove 18 and sleeved on the body of the adjustment screw 19, multiple positioning slide rods 21 vertically arranged on the side of the positioning ring 20 and with adjustment sliders 22 slidably sleeved on the rod, an adjustment disk 24 connected to the body of the adjustment screw 19 by a thread and located between the multiple adjustment sliders 22, and multiple linkage rods 23 with one end rotatably connected to different adjustment sliders 22 and the other end rotatably connected to the side of the adjustment disk 24. The adjustment screw 19 is driven by an adjustment motor 7 installed on the end of the positioning post 4. The adjustment motor 7 is installed on the positioning post 4 by a mounting block 6.

[0051] In this embodiment, when it is necessary to adjust the magnetic force and range of action of the magnetic component to better adapt to the limiting requirements of the wire rope under different working conditions, the adjusting motor 7, which is fixed to the end of the positioning column 4 by the mounting block 6, is activated. The operation of the adjusting motor 7 drives the adjusting screw 19 to rotate. Since the adjusting disc 24 is threadedly connected to the adjusting screw 19, the adjusting disc 24 will move along the axial direction of the adjusting screw 19 when the adjusting screw 19 rotates. Furthermore, since one end of each of the multiple linkage rods 23 is rotatably connected to a different adjusting slider 22, and the other end is rotatably connected to the side of the adjusting disc 24, when the adjusting disc 24 moves, it will drive the adjusting slider 22 to slide on the positioning slide rod 21 through the linkage rods 23. The multiple adjusting magnets 25 are arranged in a circumferential array along the axial direction of the adjusting groove 18. The sliding of the adjusting slider 22 will change the relative positional relationship between the adjusting magnets 25, thereby changing the magnetic field distribution generated by the entire magnetic component. The positioning ring 20 passes through the center of the opening of the adjusting groove 18 and is sleeved on the adjusting screw 19, serving to stabilize and position the adjusting structure and ensure smooth adjustment. Through this adjustment mechanism, the magnitude and range of the magnetic force generated by the magnetic component can be flexibly adjusted according to the material and thickness of the wire rope and the required limiting force in the actual working environment. This optimizes the limiting effect of the limiting component on the wire rope, ensuring stable position of the wire rope during measurement and improving the accuracy and reliability of wire rope diameter measurement.

[0052] In this embodiment, the adjusting motor 7 drives the adjusting screw 19, which in turn moves the adjusting disc 24. This, in turn, causes the adjusting slider 22 to slide via the linkage rod 23, changing the relative position between the adjusting magnets 25. This allows for flexible adjustment of the magnetic force and range of action of the magnetic components, adapting to the limiting requirements of the wire rope under different working conditions and ensuring the accuracy of the wire rope diameter measurement.

[0053] like Figures 1-3 As shown, the installation assembly includes connecting rods 8 symmetrically installed in pairs on the side of each measuring block 1, buffer blocks 11 installed below the overlapping ends of the two connecting rods 8, buffer discs 9 fitted onto the buffer blocks 11 through buffer grooves 10 on the top end face, and mounting brackets 13 connecting the two buffer discs 9. Multiple positioning springs 12 are arranged in a circular array inside the buffer grooves 10, and each positioning spring 12 is connected at both ends to the groove wall of the buffer groove 10 and the side of the buffer block 11, respectively. When the two measuring blocks 1 are installed on the wire rope, the ends of the two connecting rods 8 located on the same side of the two measuring blocks 1 overlap.

[0054] In this embodiment, when two measuring blocks 1 are assembled and fitted onto the wire rope through measuring grooves 2 on opposite sides, the ends of the two connecting rods 8 located on the same side of the two measuring blocks 1 will overlap due to the design of the mounting assembly. At this time, the buffer block 11 installed below the overlapping ends of the two connecting rods 8 will be in place, and the buffer disc 9 will be fitted onto the buffer block 11 through the buffer groove 10 on its top end face, completing the initial connection assembly. When the wire rope vibrates or is impacted by external force, this vibration will be transmitted to the measuring blocks 1, causing the connecting rods 8 to have a certain displacement tendency. The multiple positioning springs 12 arranged in a circumferential array between the buffer block 11 and the buffer disc 9 will then play a role. The two ends of the positioning springs 12 are respectively connected to the groove wall of the buffer groove 10 and the side of the buffer block 11. When subjected to the force generated by vibration, the positioning springs 12 will undergo elastic deformation, absorbing and dissipating this energy, thereby slowing down the displacement speed and amplitude of the connecting rods 8, and playing a role in buffering and shock absorption. Finally, the two buffer discs 9 are connected by the mounting bracket 13, so that the entire mounting assembly forms a stable whole structure, which further enhances the fixing effect of the two measuring blocks 1 in the length direction of the wire rope, ensuring that the measuring blocks 1 will not loosen or shift due to the vibration of the wire rope or the action of external force, and provides a stable foundation for the subsequent accurate measurement of the wire rope diameter.

[0055] In this embodiment, the two measuring blocks 1 are initially connected by the connecting rod 3. The buffer block 11, the buffer plate 9 and the positioning spring 12 are used to achieve buffering and shock absorption. Then, the overall structure is stably connected with the help of the mounting frame 13, which effectively fixes the position of the two measuring blocks 1 in the length direction of the wire rope, reduces the influence of wire rope vibration or external force on the measuring blocks 1, and ensures the stability and accuracy of wire rope diameter measurement.

[0056] like Figure 1 and Figure 2 As shown, the inner wall of the measuring groove 2 is provided with semi-annular lighting grooves 14 at symmetrical positions above and below the acquisition groove 16, and light strips 15 are provided in the lighting grooves 14.

[0057] A method for measuring the diameter of a steel wire rope based on visual displacement compensation includes the following steps:

[0058] Step 1: Use at least three industrial cameras 17 to acquire images of the wire rope from different angles. Specifically, adjust the shooting frequency of the industrial cameras according to the running speed of the wire rope to ensure that clear images of the wire rope are acquired.

[0059] Step 2: Denoise and convert the acquired image to grayscale;

[0060] Step 3: The preprocessed image is smoothed using an improved Kalman filter method. Then, the gradient magnitude and direction of the smoothed image are calculated by taking partial derivatives. Maximum suppression is performed based on the gradient magnitude and direction. Finally, the Otsu algorithm based on binary search is used to calculate the high and low thresholds. The edge image of the wire rope is obtained by comparing the thresholds.

[0061] Step 4: Perform Hough transform on the edge image to obtain the target straight line of the steel wire rope in the image;

[0062] Step 5: Based on the calibration parameters of the industrial camera, convert the target straight line in the image coordinate system into a straight line in the actual spatial coordinate system, and calculate the displacement compensation caused by the vibration or offset of the wire rope.

[0063] Step 6: Based on the compensated target straight line, and combined with the calibration relationship between the pixel size of the wire rope in the image and its actual size, calculate the diameter of the wire rope;

[0064] Step 7: Display the measured wire rope diameter on the control and display module, and store the measured wire rope diameter data in the data storage unit.

[0065] This embodiment accurately acquires the edge information of the wire rope through multi-angle image acquisition, precise image preprocessing, and edge detection. Utilizing Hough transform and displacement compensation calculations, it effectively eliminates the influence of wire rope vibration or offset on the measurement results. By combining the calibration relationship between pixel size and actual size, it achieves high-precision wire rope diameter measurement. Finally, through result display and data storage, it provides strong support for wire rope operation monitoring and subsequent analysis. It boasts advantages such as high measurement accuracy, strong anti-interference capability, and good real-time performance, meeting the actual needs of wire rope diameter measurement in industrial production.

[0066] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wire rope diameter measuring device based on visual displacement compensation, characterized in that, The system includes an installation mechanism that is fitted onto the wire rope and vibrates synchronously with the wire rope; at least three industrial cameras (17) arranged in a circumferential array around the wire rope on the installation mechanism; an image preprocessing module that connects to the industrial cameras (17) and performs noise reduction and grayscale processing on the acquired images; an edge detection module that connects to the preprocessing module and obtains the edge image of the wire rope through the preprocessed image; a processing module that connects to the edge detection module, converts the edge image into a straight line in the actual spatial coordinate system, calculates the displacement compensation amount caused by the vibration or vibration of the wire rope relative to the installation mechanism, and calculates the diameter of the wire rope; and a control and display module. The mounting mechanism includes two measuring blocks (1) fitted onto a steel wire rope by having measuring grooves (2) opened on opposite sides, two sets of limiting components that are symmetrically engaged on the steel wire rope and respectively set above and below the two measuring blocks (1), and a mounting component that fixes the two measuring blocks (1) in the position along the length of the steel wire rope. Multiple industrial cameras (17) are mounted in a circular array on the inner wall of the measuring groove (2).

2. The wire rope diameter measuring device based on visual displacement compensation according to claim 1, characterized in that, The limiting assembly includes two positioning posts (4) respectively installed on the same end of two measuring blocks (1) via connecting rods (3), a rotating ring (5) rotatably set on the side of the positioning post (4) and having an annular groove on the side that matches the side of the wire rope, and a magnetic component set in the positioning post (4).

3. The wire rope diameter measuring device based on visual displacement compensation according to claim 2, characterized in that, The positioning column (4) has an adjustment groove (18) at one end. The magnetic components include multiple adjustment magnets (25) arranged in a circular array along the axial direction of the adjustment groove (18), an adjustment screw (19) passing between the multiple adjustment magnets (25), a positioning ring (20) passing through the middle of the opening of the adjustment groove (18) and sleeved on the body of the adjustment screw (19), multiple positioning slide rods (21) vertically arranged on the side of the positioning ring (20) and with adjustment sliders (22) slidably sleeved on the rod, an adjustment disk (24) connected by a thread to the body of the adjustment screw (19) and located between the multiple adjustment sliders (22), and multiple linkage rods (23) with one end rotatably connected to different adjustment sliders (22) and the other end rotatably connected to the side of the adjustment disk (24). The adjustment screw (19) is driven by an adjustment motor (7) installed on the end of the positioning column (4). The adjustment motor (7) is installed on the positioning column (4) by a mounting block (6).

4. The wire rope diameter measuring device based on visual displacement compensation according to any one of claims 1 to 3, characterized in that, The mounting components include connecting rods (8) symmetrically mounted in pairs on the sides of each measuring block (1), buffer blocks (11) mounted below the overlapping ends of the two connecting rods (8), buffer discs (9) fitted onto the buffer blocks (11) through buffer grooves (10) on the top end face, and mounting brackets (13) connecting the two buffer discs (9). Multiple positioning springs (12) are arranged in a circular array inside the buffer grooves (10), and each positioning spring (12) is connected at both ends to the wall of the buffer groove (10) and the side of the buffer block (11). When the two measuring blocks (1) are mounted on the wire rope, the ends of the two connecting rods (8) located on the same side of the two measuring blocks (1) overlap.

5. The wire rope diameter measuring device based on visual displacement compensation according to claim 1, characterized in that, The edge detection module uses an improved Kalman filter to smooth the preprocessed image, then calculates the gradient magnitude and direction of the smoothed image by taking partial derivatives, performs maximum suppression based on the gradient magnitude and direction, and finally uses the Otsu algorithm based on binary search to calculate the high and low thresholds. The edge image of the wire rope is obtained by comparing the thresholds. The improved Kalman filtering method constructs a two-dimensional fractional-order stochastic discrete space state model, and based on this model, obtains a two-dimensional discrete Kalman filtering algorithm for smoothing images.

6. The wire rope diameter measuring device based on visual displacement compensation according to claim 1, characterized in that, When processing the edge image of the wire rope, the processing module performs Hough transform on the edge image in sequence to obtain the target straight line of the wire rope in the image. Based on the calibration parameters of the industrial camera, the target straight line in the image coordinate system is converted into a straight line in the actual spatial coordinate system. The displacement compensation amount caused by the vibration or offset of the wire rope is calculated. Then, based on the compensated target straight line and the calibration relationship between the pixel size of the wire rope in the image and its actual size, the diameter of the wire rope is calculated.

7. The wire rope diameter measuring device based on visual displacement compensation according to claim 1, characterized in that, In the processing module, the calibration parameters of the industrial camera include internal parameters and external parameters, which are obtained by calibrating the industrial camera using a calibration board. The internal parameters include focal length and principal point coordinates, while the external parameters include the camera's position and orientation.

8. A method for measuring the diameter of a steel wire rope based on visual displacement compensation, applied to the steel wire rope diameter measuring device based on visual displacement compensation as described in claim 1, characterized in that, Includes the following steps: Step 1: Use at least three industrial cameras (17) to acquire images of the wire rope from different angles; Step 2: Denoise and convert the acquired image to grayscale; Step 3: The preprocessed image is smoothed using an improved Kalman filter method. Then, the gradient magnitude and direction of the smoothed image are calculated by taking partial derivatives. Maximum suppression is performed based on the gradient magnitude and direction. Finally, the Otsu algorithm based on binary search is used to calculate the high and low thresholds. The edge image of the wire rope is obtained by comparing the thresholds. Step 4: Perform Hough transform on the edge image to obtain the target straight line of the steel wire rope in the image; Step 5: Based on the calibration parameters of the industrial camera, convert the target straight line in the image coordinate system into a straight line in the actual spatial coordinate system, and calculate the displacement compensation caused by the vibration or offset of the wire rope. Step 6: Based on the compensated target straight line, and combined with the calibration relationship between the pixel size of the wire rope in the image and its actual size, calculate the diameter of the wire rope; Step 7: Display the measured wire rope diameter on the control and display module.

9. The method for measuring the diameter of a steel wire rope based on visual displacement compensation according to claim 8, characterized in that, In step one, the shooting frequency of the industrial camera is adjusted according to the running speed of the wire rope to ensure that clear images of the wire rope are captured.

10. The method for measuring the diameter of a steel wire rope based on visual displacement compensation according to claim 8, characterized in that, In step seven, the measured wire rope diameter data is stored in the data storage unit.

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