A conveyor belt thickness measuring device and method, and a conveyor

Abstract

The present invention belongs to the technical field of machine vision non-destructive testing, and particularly relates to a conveyor belt thickness measuring device and method, and a conveyor. By means of this device, structured light is projected onto the conveyor belt, and a photo with structured light on the conveyor belt is acquired. The photo is subjected to sub-pixel processing to obtain a set of two-dimensional coordinates. Through calculation, the set of two-dimensional coordinates is converted into arithmetic information S. The true thickness information on the conveyor belt is obtained to correct the set of number information S, and the full-section thickness information of the conveyor belt is obtained. This method combines visual measurement technology and linear measurement technology, and combines the true thickness of the conveyor belt with visual measurement technology. The present invention can accurately measure the full-section thickness of the conveyor belt, reduce the parallax and measurement errors that may occur due to factors such as light in the traditional method, and has strong practicability, reliability and safety, providing strong technical support for the maintenance and management of the mining conveying system.

Description

Technical Field

[0001] The present invention belongs to the technical field of non-destructive testing in machine vision, and specifically relates to a conveyor belt thickness measuring device and method, and a conveyor. Background Art

[0002] In the field of bulk material transportation, conveyor belts are important material conveying equipment. Their operating status and structural integrity directly affect production efficiency and safety. Among them, the thickness monitoring of conveyor belts is one of the key factors to ensure the stable operation of the conveying system. Traditional thickness monitoring methods mainly rely on manual inspection or simple mechanical measuring instruments. These methods are not only inefficient but also unable to meet the precise measurement requirements under large widths, full cross-sections, and complex working conditions.

[0003] With the development of industrial automation and informatization, vision measurement technology has gradually been applied to the field of conveyor belt thickness monitoring due to its non-contact and efficient characteristics. For example, the Chinese invention with the patent number CN202322294174.0 discloses a conveying distance measuring mechanism for a conveyor. Although this measuring mechanism can efficiently measure the thickness of the conveyor belt, it is difficult to achieve high-precision and high-stability measurement results due to factors such as lighting conditions and environmental interference. Summary of the Invention

[0004] In view of this, the present invention provides a conveyor belt thickness measuring device and method, and a conveyor to solve the technical problem that the thickness of the conveyor belt measured by the existing conveyor belt thickness measuring method and device is inaccurate.

[0005] To achieve the above object, the present application adopts the following solutions:

[0006] A conveyor belt thickness measuring device includes mounting frames arranged on both sides of the conveyor belt, and an image capture device, a specific point thickness acquisition device, a lateral coordinate capture device, and a control module arranged on the mounting frames;

[0007] The image capture device includes a line laser generator and an industrial camera arranged in pairs with the conveyor belt as the center. The line laser generator is arranged on the mounting frame and is used to project a structured light band on the conveyor belt, and the industrial camera is used to obtain a photo of the conveyor belt with the structured light band;

[0008] The specific point thickness acquisition device is movably matched with the mounting frame along the width direction of the conveyor belt, and the specific point thickness acquisition device is used to obtain the thickness information of the conveyor belt;

[0009] The lateral coordinate capture device is used to capture the lateral coordinate information of the specific point thickness acquisition device;

[0010] The control module is electrically connected to the industrial camera, the specific point thickness acquisition device, and the lateral coordinate capture device, and is configured to process the photo, the thickness information, and the lateral coordinate information, and calculate and output the full-section thickness information.

[0011] Preferably, an obstacle avoidance device is further included. The obstacle avoidance device includes a pair of obstacle avoidance components symmetrically arranged on the layout frame with the conveyor belt as the center. Each obstacle avoidance component includes a horizontal mounting frame, an obstacle detection member, a servo motor group, and a pair of longitudinal electric telescopic cylinders. The pair of longitudinal electric telescopic cylinders are respectively arranged on the layout frame along the vertical direction and are located on both sides of the conveyor belt. The horizontal mounting frame is horizontally arranged and is connected between the telescopic ends of the pair of longitudinal electric telescopic cylinders. The obstacle detection member is arranged on the horizontal mounting frame. The fixed end of the servo motor group is arranged on the layout frame. The industrial camera is arranged on the layout frame through the servo motor group, and the industrial camera is arranged at the telescopic end of the servo motor group. The obstacle detection member, the servo motor group, and the pair of longitudinal electric telescopic cylinders are all electrically connected to the control module.

[0012] Preferably, the specific point thickness acquisition device includes a pair of displacement lead screws and displacement sensors arranged symmetrically with the conveyor belt as the center. The displacement lead screws are arranged on the placement frame, and the displacement sensors are arranged on the mobile ends of the displacement lead screws. The displacement lead screws are used to drive the displacement sensors to move along the width direction of the conveyor belt.

[0013] Preferably, the lateral coordinate capture device includes an ultrasonic sensor arranged on one side of the conveyor belt. The ultrasonic sensor is arranged on the layout frame and is electrically connected to the control module, and is configured to detect the position of the displacement sensor and send the lateral coordinate information to the control module.

[0014] A conveyor includes the conveyor belt thickness measurement device according to any one of the above, and the conveyor belt thickness measurement device is configured to detect the full-section thickness of the conveyor belt on the conveyor.

[0015] A conveyor belt thickness measurement method includes the following steps:

[0016] S1: Obtain the contour information K of the conveyor belt: Project structured light bands onto the upper and lower surfaces of the conveyor belt respectively, take photos of the upper and lower surfaces of the conveyor belt with the structured light bands respectively, and perform sub-pixel processing on the photos to obtain image information. Calculate the contour information K through an image algorithm according to the image information. The contour information K is a set of pixel two-dimensional coordinates of the cross-section corresponding to the surface of the conveyor belt covered by the structured light band. The contour information K has a number of lateral coordinate values x and a number of longitudinal pixel values y;

[0017] S2: Calculate the arithmetic information S of the conveyor belt: Calculate the mapping relationship t of pixel values. According to the mapping relationship t, convert the contour information K into a set of arithmetic information S corresponding to the cross-section of the structured light band. Each piece of arithmetic information S has a horizontal coordinate value w* and a longitudinal thickness value h*;

[0018] S3: Obtain the correction information J0 of the correction point: Obtain the true thickness h of any point on the conveyor belt, and obtain the horizontal coordinate w of this point along the width direction of the conveyor belt. This point is the correction point, and the true thickness h and the horizontal coordinate w are the correction information J0;

[0019] S4: Obtain the arithmetic information S0 of the correction information J0: Among the set of arithmetic information S, the arithmetic information with w = w* is the arithmetic information S0 of the correction point J0. The arithmetic information S0 has a horizontal coordinate value w*0 and a longitudinal thickness value h*0;

[0020] S5: Calculate the correction thickness H: Calculate the pixel difference D through the contour information K and the true thickness h. Calculate the correction thickness H according to the mapping relationship t and the pixel difference D. Add the product values of each longitudinal thickness value h* and the pixel difference D and the mapping relationship t respectively to obtain a set of correction thicknesses H. The set of correction thicknesses H is the full-section thickness information.

[0021] Preferably, the structured light band is a pair of one-dimensional laser beams located in the same cross-section projected on the upper and lower surfaces of the conveyor belt, and the one-dimensional laser beam covers the entire width of the conveyor belt.

[0022] Preferably, the step S2 includes the following steps:

[0023] S21: The specific steps for solving the mapping relationship t are as follows: The computer obtains the pixel width L* of the structured light band in the image information, with the unit of mm. The computer obtains the field of view width L of the structured light band in the photo, with the unit of pix. Then the mapping relationship t is In the mapping relationship t, b is the sub-pixel processing effect coefficient, and the unit of the mapping relationship t is mm / pix;

[0024] S22: When converting the contour information K into a set of the arithmetic information S according to the mapping relationship t, the conversion formulas for the horizontal coordinate value w* and the longitudinal thickness value h* of each piece of arithmetic information S are:

[0025] Preferably, the step S5 includes the following steps:

[0026] S51: Obtain the contour information K0 corresponding to the correction point: Among a set of contour information K, The contour information is the contour information K0 corresponding to the correction point;

[0027] S52: Calculate the longitudinal pixel value y0 corresponding to the true thickness h according to the mapping relationship t and the true thickness h. The solution formula for the longitudinal pixel value y0 is: Replace the longitudinal pixel value in the contour information K0 with the longitudinal pixel value y0;

[0028] S53: The solution formula for the pixel difference D is: D = y - y0. The unit of the pixel difference D is pix, where y is the remaining longitudinal pixel values in the set of contour information K where the longitudinal pixel value y0 is located.

[0029] Preferably, it further includes an S6 adaptive obstacle avoidance step. The adaptive obstacle avoidance step includes the following steps:

[0030] S61: Perform ultrasonic detection on the front, rear, and above of the conveyor belt respectively. If an obstacle is found on the conveyor belt, go to S62; otherwise, jump to S1.

[0031] S62: Generate the obstacle avoidance signal, and the conveyor belt thickness measuring device responds to the obstacle avoidance signal to adjust its working posture for obstacle avoidance.

[0032] The technical solution adopted in this application can achieve the following beneficial effects:

[0033] The specific point thickness acquisition device in the conveyor belt thickness measuring device provided by the present invention can accurately measure the thickness information of a specific point on the conveyor belt. The lateral coordinate capture device captures the lateral coordinate information of the specific point thickness acquisition device. The image capture device can comprehensively obtain the image information of the conveyor belt. The control module calculates and corrects the thickness information, the lateral coordinate information, and the image information, and outputs the full-section thickness information and the corrected image information. The specific point thickness acquisition device can accurately measure the actual thickness of a specific point, while the image capture device provides comprehensive contour information (image information). The combination of the two provides double guarantees for accurate measurement, reducing the parallax and measurement errors that may occur in traditional methods;

[0034] The object of the present invention is to provide an accurate and efficient method for measuring the thickness of a conveyor belt. First, structured light is projected onto the conveyor belt, and a photo of the conveyor belt with the structured light is obtained. The photo is subjected to sub-pixel processing to obtain a set of two-dimensional coordinates (contour information K). By calculation, the set of two-dimensional coordinates is converted into arithmetic information S. Since errors will occur during the processes of taking photos, sub-pixel processing, image recognition, and calculation, the combined errors finally result in a large error between the arithmetic information S and the actual situation. Therefore, in this application, the true thickness h and the horizontal coordinate w of the correction points on the corresponding cross-section of the conveyor belt are obtained, and the arithmetic thickness with the same horizontal coordinate in the corresponding cross-section is found using the horizontal coordinate w, which is the arithmetic thickness value of the correction points. The pixel difference D between the longitudinal pixel value y0 of the correction point in the image information and the longitudinal pixel value y of the same cross-section is obtained. Finally, only by adding the difference calculated using the pixel difference D to the corresponding set of arithmetic information can the corrected thickness H that is closer to the actual thickness of the conveyor belt be calculated. This application improves the existing vision measurement technology. By taking advantage of the characteristic that although there is a large error between the vision measurement and the actual value, the difference between the same set of data is basically consistent with the actual situation, a method for measuring the thickness of the conveyor belt is provided, which has the characteristics of non-contact and high measurement efficiency, and the vision measurement result is more accurate than the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the device of the present invention;

[0036] Figure 2 It is a schematic diagram of the partial structure of the device of the present invention;

[0037] Figure 3 It is a schematic diagram of the irradiation of the one-dimensional laser generator in the present invention;

[0038] Figure 4 It is a performance parameter diagram of the one-dimensional laser generator in the present invention;

[0039] Figure 5 It is a schematic diagram of the installation angle of the industrial camera in the present invention;

[0040] Figure 6 It is a schematic diagram of the method flow of the present invention;

[0041] Figure 7 It is a schematic diagram of the image processing flow in the method of the present invention;

[0042] Figure 8 It is a schematic diagram of the image processing effect in the method of the present invention;

[0043] Figure 9 It is a schematic diagram of a specific case of the correction calculation in the method of the present invention;

[0044] Figure 10It is a visualization user interface diagram developed in the method of the present invention;

[0045] Figure 11 It is a diagram for measuring image data in the method of the present invention.

[0046] In the figure, there are conveyor belt 100, arrangement rack 200, linear laser generator 310, industrial camera 320, structured light band 330, laser beam 331, specific point thickness acquisition device 400, displacement lead screw 410, displacement sensor 420, ultrasonic sensor 510, control module 600, horizontal mounting rack 711, obstacle detection member 712, servo motor set 713, and electric telescopic cylinder 714. Detailed implementation manners

[0047] To facilitate the understanding of the present application, the present application will be described more comprehensively below in conjunction with the accompanying drawings. And the preferred embodiments of the present application are given. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application herein are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0049] Please refer to Figures 1 to 5 , a conveyor belt 100 thickness measuring device, including arrangement racks 200 arranged on both sides of the conveyor belt 100, and an image capturing device, a specific point thickness acquisition device 400, a lateral coordinate capturing device, and a control module 600 arranged on the arrangement racks 200;

[0050] The image capturing device includes a linear laser generator 310 and an industrial camera 320 arranged in pairs with the conveyor belt 100 as the center. The linear laser generator 310 is arranged on the arrangement rack 200 and is used to project a structured light band 330 on the conveyor belt 100. The industrial camera 320 is used to obtain a photo of the conveyor belt 100 with the structured light band 330;

[0051] The specific point thickness acquisition device 400 is movably matched with the arrangement rack 200 along the width direction of the conveyor belt 100, and the specific point thickness acquisition device 400 is used to obtain the thickness information of the conveyor belt 100;

[0052] The lateral coordinate capturing device is used to capture the lateral coordinate information of the specific point thickness obtaining device 400;

[0053] The control module 600 is electrically connected to the industrial camera 320, the specific point thickness obtaining device 400, and the lateral coordinate capturing device, and is used to process the photo, the thickness information, and the lateral coordinate information, calculate and output the full-section thickness information.

[0054] In a specific implementation process, the layout rack 200 is built by aluminum profiles, aluminum angle codes, hexagon socket head cap screws, and trapezoidal nuts. The size specifications and form of the layout rack 200 can be determined according to the size and form of the conveyor; the one-dimensional laser generators 310, the servo motor group 713, and the industrial camera 320 are each a pair (two), and are respectively located on both sides of the upper and lower surfaces of the conveyor belt 100; the installation angle of the industrial camera 320 is between 30° and 70°, and the field of view width of the industrial camera 320 should cover more than 90% of the width of the conveyor belt 100, and the focal length and exposure settings of the industrial camera 320 are adjusted to ensure the clarity of the image; the layout rack 200 is arranged on both sides of the conveyor, and the positions of the image capturing device, the specific point thickness obtaining device 400, the lateral coordinate capturing device, and the control module 600 arranged on the layout rack 200 can be set by those skilled in the art according to the actual situation.

[0055] During use, first, a pair of the one-dimensional laser generators 310 project a one-dimensional laser beam 331 (structured light) onto the upper and lower surfaces of the conveyor belt 100 respectively; the one-dimensional laser beams 331 on the upper and lower surfaces of the conveyor belt 100 are in a plane, and this plane is the measurement plane of the full section of the conveyor belt 100; the one-dimensional laser beam 331 covers the entire width of the conveyor belt 100, and a structured light band 330 is generated on the conveyor belt 100 for a pair of industrial cameras 320 to collect, so as to obtain the image information and initially obtain the contour information of the surface of the conveyor belt 100; when the obstacle detection member 712 detects an obstacle on the conveyor belt 100 and generates an obstacle avoidance information, after the obstacle avoidance assembly adaptively expands and contracts, the position of the one-dimensional laser generator 310 on the lateral mounting rack 711 changes, resulting in a change in the position of the structured light band 330 projected onto the conveyor belt 100, and the structured light will displace within the field of view of the industrial camera 320, which will affect the consistency of the photos (i.e., image information) captured by the industrial camera 320. Therefore, the industrial camera 320 needs to correct its own field of view to continue to align with the structured light. The correction method of the industrial camera 320 is to rotate and expand according to the height of the one-dimensional laser, and its rotation and expansion driving member is the servo motor group 713.

[0056] When in use, first, confirm that the conveyor belt 100 on the conveyor is working normally, and then, a pair of the straight laser generators 310 project a straight laser beam 331 (structured light) onto the upper and lower surfaces of the conveyor belt 100 respectively; the straight laser beams 331 on the upper and lower surfaces of the conveyor belt 100 are in a plane, and the plane is the measurement surface of the full cross-section of the conveyor belt 100; the straight laser beam 331 covers the entire width of the conveyor belt 100, and the industrial camera 320 takes pictures of the conveyor belt 100 (with the straight laser beam 331) respectively, and transmits the pictures to the control module 600, and the control module 600 performs sub-pixel processing on the pictures to obtain image information; the specific point thickness acquisition device 400 and the arrangement frame 200 moves along the width direction of the conveyor belt 100 to obtain the thickness information of a certain point of the conveyor belt 100. It should be noted that the thickness information is the real thickness information of the conveyor belt 100; at the same time, the transverse coordinate capture device captures the transverse coordinate information of the specific point thickness acquisition device 400, that is, the transverse coordinate that can correspond one-to-one with the above-mentioned thickness information, and sends the thickness information and the transverse coordinate information of the corresponding point to the control module 600; the control module 600 receives the image information, the thickness information and the transverse coordinate information, and processes them, calculates and transmits the full-section thickness information and the corrected image information through an algorithm, and the output method can be any graphic form that is easy for users to quickly understand.

[0057] Beneficial effects: The specific point thickness acquisition device 400 in the conveyor belt thickness measurement device provided by the present invention can accurately measure the thickness information of the specific point of the conveyor belt 100, the transverse coordinate capture device captures the transverse coordinate information of the specific point thickness acquisition device 400, the image capture device can fully acquire the image information of the conveyor belt 100, and the control module 600 calculates and corrects the thickness information, the transverse coordinate information and the image information, and outputs the full-section thickness information and the corrected image information. The specific point thickness acquisition device 400 can accurately measure the actual thickness of the specific point, while the image capture device provides comprehensive profile information (image information). The combination of the two provides double guarantee for accurate measurement and reduces the parallax and measurement errors that may occur in traditional methods.

[0058] In the above implementation process, during the thickness detection of the conveyor belt 100, some obstacles are brought on the conveyor belt 100. These obstacles will block the laser beam 331 emitted by the line laser and also interfere with the industrial camera 320 taking pictures of the structured light band 330. In a possible embodiment, an obstacle avoidance device is further included. The obstacle avoidance device includes a pair of obstacle avoidance components symmetrically arranged on the arrangement frame 200 with the conveyor belt 100 as the center. The obstacle avoidance component includes a horizontal mounting frame 711, an obstacle detection member 712, a servo motor group 713, and a pair of longitudinal electric telescopic cylinders 714. The pair of longitudinal electric telescopic cylinders are respectively arranged on the arrangement frame 200 in the vertical direction and are respectively located on both sides of the conveyor belt 100. The horizontal mounting frame 711 is horizontally arranged and is connected between the telescopic ends of the pair of longitudinal electric telescopic cylinders. The obstacle detection member 712 is arranged on the horizontal mounting frame 711. The fixed end of the servo motor group 713 is arranged on the arrangement frame 200. The industrial camera 320 is arranged on the arrangement frame 200 through the servo motor group 713, and the industrial camera 320 is arranged at the telescopic end of the servo motor group 713. The obstacle detection member 712, the servo motor group 713, and the pair of longitudinal electric telescopic cylinders 714 are all electrically connected to the control module 600. In a specific implementation process, the obstacle detection member 712 can obtain the spatial coordinate information of the obstacles appearing on the conveyor belt 100, and generate corresponding obstacle avoidance information according to the spatial coordinate information of the obstacles, and input the obstacle avoidance information into the longitudinal electric telescopic cylinder 714 and the servo motor group 713, so that the longitudinal electric telescopic cylinder 714 and the servo motor group 713 expand and contract to avoid the obstacles by the line laser and the industrial camera 320, preventing the measuring device from being damaged by the obstacles.

[0059] Further, the obstacle detection member 712 is an ultrasonic detection group. The ultrasonic detection group is arranged on the horizontal mounting frame 711 above the conveyor belt 100, and emits ultrasonic waves to the conveyor belt 100 downward, forward, and backward respectively, and obtains the obstacle avoidance information. The ultrasonic detection group can emit ultrasonic waves, receive the emitted ultrasonic waves, generate the coordinate information of the obstacles by analyzing the received ultrasonic waves, and can also calculate and generate the obstacle avoidance information for controlling the longitudinal electric telescopic cylinder 714 and the servo motor group 713 to perform corresponding obstacle avoidance telescopic actions according to the coordinate information of the obstacles.

[0060] In the above implementation process, to adapt to more working conditions and enable the specific point thickness acquisition device 400 to move, in a possible embodiment, the specific point thickness acquisition device 400 includes a displacement lead screw 410 and a displacement sensor 420 that are arranged in pairs with the conveyor belt 100 as the center. The displacement lead screw 410 is arranged on the placement rack, and the displacement sensor 420 is arranged at the moving end of the displacement lead screw 410. The displacement lead screw 410 is used to drive the displacement sensor 420 to move along the width direction of the conveyor belt 100.

[0061] In the above implementation process, to determine the specific position of the conveyor belt 100 in the transverse direction, in a possible embodiment, the transverse coordinate capture device includes an ultrasonic sensor 510 arranged on one side of the conveyor belt 100. The ultrasonic sensor 510 is arranged on the layout rack 200, and the ultrasonic sensor 510 is electrically connected to the control module 600, and is used to detect the position of the displacement sensor 420 and send the transverse coordinate information to the control module 600.

[0062] The present invention also provides a conveyor, including the conveyor belt 100 thickness measurement device as described in any one of the above.

[0063] For a method of measuring the thickness of the conveyor belt 100 in this application, those skilled in the art can understand its essence through reading, and thus use different devices to implement this method. However, in order to make this method more concrete and easy to understand, the following will explain it in combination with the above-mentioned conveyor belt 100 thickness measurement device. However, this method can still be implemented by relying on other devices. Similarly, the protection scope of this method is not limited to and does not depend on the above-mentioned conveyor belt 100 thickness measurement device.

[0064] Please refer to Figure 6 , a method of measuring the thickness of the conveyor belt 100, including the following steps:

[0065] S1: Obtain the contour information K of the conveyor belt 100: Project structured light bands 330 onto the upper and lower surfaces of the conveyor belt 100 respectively, take photos of the upper and lower surfaces of the conveyor belt 100 with the structured light bands 330 thereon, perform sub-pixel processing on the photos to obtain image information, and calculate the contour information K through an image algorithm based on the image information. The contour information K is a set of pixel two-dimensional coordinates of the cross-section corresponding to the surface of the conveyor belt 100 covered by the structured light bands 330. The contour information K has a number of horizontal coordinate values x and a number of vertical pixel values y. The above-mentioned structured light bands 330 can be light bands of any shape. However, in this application, for the convenience of explanation, a narrow and long one-shaped light band is used as an example. A set of pixel two-dimensional coordinates are the coordinates of the one-shaped narrow long structured light band 330. For example, the pair of one-shaped laser generators 310 arranged on the upper and lower sides of the conveyor belt 100 can project the structured light bands 330 on the upper and lower sides of the same cross-section. At this time, a set of pixel two-dimensional coordinates obtained are the spatial pixel coordinates at each location along the width direction of the conveyor belt 100 on the upper and lower two structured light bands 330 of this cross-section. The vertical pixel value y is the difference obtained by subtracting the vertical coordinates of the same horizontal coordinate value x, that is, the thickness in units of pix in the sub-pixel map, which is the vertical pixel value y. Obviously, assuming this cross-section is a rectangle, by obtaining the coordinate information of the upper and lower two lines of the rectangle, the height of the rectangle (the height in this example is equivalent to the vertical pixel value y in this application) can be obtained through mathematical calculation.

[0066] S2: Calculate the arithmetic information S of the conveyor belt 100: Calculate the mapping relationship t of the pixel values, and convert the contour information K into a set of arithmetic information S corresponding to the cross-section of the structured light band 330 according to the mapping relationship t. Each arithmetic information S has a horizontal coordinate value w* and a vertical thickness value h*. This step converts the pixel unit pix of the pixel two-dimensional coordinates (horizontal coordinate value x, vertical pixel value y) into a length unit mm that is convenient for subsequent calculation and understanding. That is to say, a set of pixel two-dimensional coordinate information (horizontal coordinate value x, vertical pixel value y) and a set of arithmetic information S (horizontal coordinate value w*, vertical thickness value h*) are in one-to-one correspondence and are the same set of coordinate information for the same cross-section, only with different units.

[0067] When obtaining the arithmetic information S, a set of arithmetic information for the entire cross-section can be obtained at one time. Through the one-shaped laser and the industrial camera 320, photos of the entire corresponding structured light band 330 can be obtained at one time. In the control module 600, the photos can be processed through sub-pixel processing, image recognition, and calculation to be converted into a set of pixel two-dimensional coordinates (horizontal coordinate value x, vertical pixel value y), and then through unit conversion of the mapping relationship into a set of arithmetic information S.

[0068] S3: Obtain the correction information of the correction point J0: Obtain the actual thickness h of any point on the conveyor belt 100, and obtain the lateral coordinate w of this point along the width direction of the conveyor belt 100. This point is the correction point; the correction point is the corresponding point of the correction information J0 on the conveyor belt 100.

[0069] S4: Obtain the arithmetic information S0 of the correction information J0: Among the set of arithmetic information S, the arithmetic information with w = w* is the arithmetic information S0 of the correction point J0. The arithmetic information S0 has a lateral coordinate value w*0 and a longitudinal thickness value h*0.

[0070] The necessity of correction can be simply understood as follows: When obtaining the arithmetic information S, errors will occur in the above processes of taking pictures, sub-pixel processing, image recognition, and calculation. The combination of all errors finally leads to a large error between the arithmetic information S and the actual situation. Therefore, it is necessary to correct a set of numerical information S.

[0071] During correction, first, find the arithmetic information S0 of the correction point. Since the arithmetic information S0 of the correction point and the correction information J0 are the same data of the same point on the conveyor belt 100, and the correction information J0 is the more accurate actual information at the correction point on the conveyor belt, with a more accurate actual thickness h compared to the longitudinal thickness value h*, take the actual thickness h to correct the entire set of longitudinal thickness values h*.

[0072] S5: Calculate the corrected thickness H: In a possible embodiment, calculate the pixel difference D through the contour information K and the actual thickness h, and calculate the corrected thickness H according to the mapping relationship t and the pixel difference D. Add the product values of each longitudinal thickness value h* and the pixel difference D and the mapping relationship t respectively to obtain a set of corrected thicknesses H. The set of corrected thicknesses H is the full-section thickness information. Through the mapping relationship t, the length units of the actual thickness h and the longitudinal thickness value h*0 of the correction point are both converted from mm to pixel length units pix. Among them, when the longitudinal thickness value h*0 of the correction point is converted to pixel length units pix for counting, it is the longitudinal pixel value y1 of the correction point. After the actual thickness h is converted to pixel units, it is recorded as y0. After replacing y1 with y0, calculate the difference between the other longitudinal pixel values y and y0 in the same set of contour information K as the pixel difference D, and use the pixel difference D to solve the corrected thickness H. The solution formula for the pixel difference D is: D = y - y0. The solution formula for the corrected thickness H is as follows: H = h * + t * D.

[0073] In a specific implementation process, please refer to Figure 7 and Figure 8, Step 1: Obtain the contour information K of the conveyor belt 100. Project a narrow and long one-dimensional structured light band 330 onto the upper and lower surfaces of the conveyor belt 100 by a one-dimensional laser, and use an industrial camera 320 to take a photo of the conveyor belt 100 with the structured light band 330. Transmit the photo to the control module 600, and the control module 600 performs sub-pixel processing on the photo to obtain image information. Specifically: First, read a picture from the video using opencv, perform Gaussian filtering and grayscale processing on the picture, and then use the Canny algorithm to perform edge detection on the above picture to detect a white line. Perform bicubic interpolation processing on the white line to obtain a high-resolution image. The control module 600 calculates the contour information K according to the image information through Canny. The contour information K is a set of pixel two-dimensional coordinates (horizontal coordinate value x, vertical pixel value y) of the cross-section corresponding to the surface covered by the narrow and long one-dimensional structured light band 330 on the conveyor belt 100, with the unit of pix, that is, the spatial coordinates of the upper and lower two contour lines of the cross-section of the conveyor belt 100 traced by taking the structured light band 330 as a line segment. The coordinate system of this spatial coordinate takes the width direction of the conveyor belt 100 as the horizontal coordinate and the thickness direction of the conveyor belt 100 as the vertical coordinate. Therefore, the vertical pixel value y is the absolute value of the difference between the vertical coordinate values of the upper and lower two traced contour lines of this cross-section, and the horizontal coordinate value x is the value of the horizontal coordinate;

[0074] Step 2, calculate the arithmetic information S of the conveyor belt 100: Please refer to Figure 9 , calculate the mapping relationship t of the pixel values. The mapping relationship t is the conversion ratio between the pixel values on the photo after sub-pixel processing and the actual length unit in space during photo shooting. Through the mapping relationship t, obtain a set of arithmetic information S (horizontal coordinate value w*, vertical thickness value h*) corresponding to the cross-section of the structured light band 330. The set of arithmetic information S (horizontal coordinate value w*, vertical thickness value h*) obtained through conversion corresponds one-to-one with a set of pixel two-dimensional coordinate information (horizontal coordinate value x, vertical pixel value y), which is the same set of coordinate information for the same cross-section, only with different units;

[0075] When obtaining the arithmetic information S, errors will occur during the above processes of taking photos, sub-pixel processing, image recognition, and calculation. All the errors combined will finally lead to a large error between the arithmetic information S and the actual situation. Therefore, it is necessary to correct a set of numerical information S. So, the third step is required, which is to obtain the correction information J0 of the correction point: Obtain the true thickness h of any point on the conveyor belt 100 through the displacement sensor 420, and obtain the horizontal coordinate w of this point on the conveyor belt 100 along the width direction of the conveyor belt 100 through the ultrasonic sensor 510. This point is the correction point. Store the obtained information in the control module 600. The control module 600 organizes it into the correction information J0 of the correction point as (horizontal coordinate w, true thickness h), and stores it for later use;

[0076] Fourth step, correct the image information and arithmetic information S using the correction information J0: The control module 600 finds the arithmetic information S0 of the correction point from a set of arithmetic information S. The control module 600 calculates the difference between the vertical pixel value of the correction point and other vertical pixel values in the same set of contour information K, which is denoted as the pixel difference D for later use. The arithmetic information with w = w* is the arithmetic information S0 of the correction point J0. The arithmetic information S0 of the correction point is denoted as (horizontal coordinate value w*0, vertical thickness value h*0).

[0077] Fifth step, according to the specific calculation formula of the corrected thickness H: H = h * + t*D, use the software designed by Qt to process, calculate, and fuse and correct the collected image information and the data (horizontal coordinate w) obtained by the sensor to obtain the full-section thickness information of the conveyor belt.

[0078] This method combines visual measurement technology and linear measurement technology. By combining the true thickness of the conveyor belt 100 with visual measurement technology, the present invention can accurately measure the full-section thickness of the conveyor belt 100, reducing the parallax and measurement errors that may occur due to factors such as lighting in the traditional method. The output form is as Figure 10 shown, which may include the true thickness, minimum value, maximum value, mean value of the correction point, full-section thickness information, and image information. All thickness values are stored in the form of an array. Analyze the obtained thickness data to determine whether there is abnormal wear or damage, and predict the remaining service life and maintenance time of the conveyor belt 100 according to the thickness data.

[0079] The thickness measuring device of the conveyor belt 100 adjusts its working posture in response to the obstacle avoidance information. Therefore, when measuring the thickness of the conveyor belt 100, it can adapt to conveyor belts 100 of different widths and types, having high flexibility and adaptability. Whether on narrow-width or wide-width conveyor belts 100, this method can be effectively implemented, meeting the diverse industrial application requirements.

[0080] As Figure 11 shown, the full-section thickness data of the conveyor belt 100 is displayed using a Cartesian coordinate system. When measuring the thickness using the method of the present invention, its accuracy can reach ±0.2 mm, which is much higher than the accuracy of traditional manual measurement methods. In addition, due to the adoption of advanced equipment and technology, the method of the present invention also has significant advantages in terms of operation simplicity, automation degree, and data processing speed.

[0081] The method provided by the present invention not only improves the accuracy of measuring the thickness of the conveyor belt 100, but also the technical effects are reflected in the following aspects:

[0082] Improve efficiency: Automated data collection and processing greatly improve the efficiency of measurement. This invention requires little manual intervention, can quickly complete the measurement task, and provide instant data feedback, which is particularly important for occasions that require long-term continuous monitoring;

[0083] Optimize safety: Real-time monitoring of the thickness status of the conveyor belt 100 helps prevent the failure of the conveyor belt 100 caused by excessive wear, and improves the safety of the entire conveyor system;

[0084] Data tracking and analysis: This invention makes the tracking of the thickness data of the conveyor belt 100 more comprehensive, facilitating historical data analysis, timely predicting and discovering potential problems, and providing data support for maintenance decisions.

[0085] In summary of the above technical effects, this invention not only provides an efficient and accurate method for measuring the full cross-section thickness of the mine conveyor belt 100, but also has strong practicability and reliability, providing strong technical support for the maintenance and management of the mining conveyor system.

[0086] Further, a pair of one-dimensional laser beams 331 located in the same cross-section are respectively projected onto the upper and lower surfaces of the conveyor belt 100 by a one-to-one one-dimensional laser generator 310, and the one-dimensional laser beam 331 covers the width of the conveyor belt 100.

[0087] Further, the step S2 includes the following steps:

[0088] S21: The specific steps for solving the mapping relationship t are as follows: The computer obtains the pixel width L* of the structured light band 330 in the image information, in mm, and the computer obtains the field of view width of the structured light band 330 in the photo as L, in pix. Then the mapping relationship t is In the mapping relationship t, b is the sub-pixel processing effect coefficient, and the unit of the mapping relationship t is mm / pix;

[0089] S22: According to the mapping relationship t, convert the contour information K into a set of arithmetic information S. The conversion formulas for the horizontal coordinate value w* and the vertical thickness value h* of each arithmetic information S are:

[0090] Specifically, the step S5 includes the following steps:

[0091] S51: Obtain the contour information K0 corresponding to the correction point: Among a set of contour information K, the contour information is the contour information K0 corresponding to the correction point;

[0092] S52: Calculate the longitudinal pixel value y0 corresponding to the true thickness h according to the mapping relationship t and the true thickness h. The solution formula for the longitudinal pixel value y0 is as follows: Replace the longitudinal pixel value in the contour information K0 with the longitudinal pixel value y0;

[0093] S53: The solution formula for the pixel difference D is: D = y - y0. The unit of the pixel difference D is pix, where y is the remaining longitudinal pixel values in the group of contour information K where the longitudinal pixel value y0 is located.

[0094] Furthermore, it further includes an S6 adaptive obstacle avoidance step. The adaptive obstacle avoidance step includes the following steps:

[0095] S61: Perform ultrasonic detection on the front, rear, and above of the conveyor belt 100 respectively. If an obstacle is found on the conveyor belt 100, perform S62; otherwise, jump to S1.

[0096] S62: Generate the obstacle avoidance signal, and the thickness measuring device of the conveyor belt 100 responds to the obstacle avoidance signal to adjust its working posture for obstacle avoidance.

[0097] Detect obstacles on the conveyor belt 100 through the obstacle detection member 712. If there are obstacles on the conveyor belt 100, the obstacle detection member 712 can detect the obstacles and generate obstacle avoidance information. Specifically: The obstacle detection member 712 sends the obstacle information to the control module 600. The control module 600 processes the obstacle information, generates obstacle avoidance information and sends the obstacle avoidance information to the obstacle avoidance device. The obstacle avoidance device responds to the obstacle avoidance information to adjust the working posture of the image capture device. The obstacle avoidance device responds to the obstacle avoidance information to adjust the working posture of the image capture device, that is, adjusts the image capture device to a working posture that can avoid obstacles for the obstacle, so as to prevent the obstacle from affecting the measurement result.

[0098] It should be noted that the displacement sensor used in this application needs to be calibrated before use to obtain a more accurate true thickness h, so as to avoid deviation in the calibration result. The specific calibration method can adopt the calibration method of the displacement sensor in the existing technology.

[0099] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention.

Claims

1. A conveyor belt thickness measurement method, characterized in that, It includes the following steps: S1: Obtain the contour information K of the conveyor belt: Project structured light bands onto the upper and lower surfaces of the conveyor belt respectively, take photos of the upper and lower surfaces of the conveyor belt with the structured light bands respectively, perform sub-pixel processing on the photos to obtain image information, and calculate the contour information K through image algorithms according to the image information. The contour information K is a set of pixel two-dimensional coordinates of the cross-section corresponding to the surface of the conveyor belt covered by the structured light band. The contour information K has several horizontal coordinate values x and several vertical pixel values y; S2: Calculate the arithmetic information S of the conveyor belt: Calculate the mapping relationship t of the pixel values, and convert the contour information K into a set of arithmetic information S corresponding to the cross-section of the structured light band according to the mapping relationship t. Each arithmetic information S has a horizontal coordinate value w* and a vertical thickness value h*; S3: Obtain the calibration information J0 of the calibration point: Obtain the actual thickness h of any point on the conveyor belt and the horizontal coordinate w of this point along the width direction of the conveyor belt. This point is the calibration point. The actual thickness h and the horizontal coordinate w are the calibration information J0; S4: Obtain the arithmetic information S0 of the calibration information J0: Among the set of arithmetic information S, the arithmetic information with w = w* is the arithmetic information S0 of the calibration point J0. The arithmetic information S0 has a horizontal coordinate value w*0 and a vertical thickness value h*0; S5: Calculate the calibrated thickness H: Calculate the pixel difference D through the contour information K and the actual thickness h, and calculate the calibrated thickness H according to the mapping relationship t and the pixel difference D. Add the product values of each vertical thickness value h* and the pixel difference D and the mapping relationship t respectively to obtain a set of calibrated thicknesses H. The set of calibrated thicknesses H is the full-section thickness information; The step S2 includes the following steps: S21: The specific steps for solving the mapping relationship t are as follows: The computer obtains the pixel width L* of the structured light band in the image information, with the unit of mm. The computer obtains the field of view width of the structured light band in the photo as L, with the unit of pix. Then the mapping relationship In the mapping relationship t, b is the sub-pixel processing effect coefficient, and the unit of the mapping relationship t is mm / pix; S22: According to the mapping relationship t, convert the contour information K into a set of the arithmetic information S. The conversion formulas for the horizontal coordinate value w* and the vertical thickness value h* of each piece of the arithmetic information S are as follows: The step S5 includes the following steps: S51: Obtain the contour information corresponding to the correction point K0: Among a set of contour information K, the contour information is the contour information K0 corresponding to the correction point; S52: Calculate the longitudinal pixel value y0 corresponding to the true thickness h according to the mapping relationship t and the true thickness h. The solution formula for the longitudinal pixel value y0 is as follows: Replace the longitudinal pixel value in the contour information K0 with the longitudinal pixel value y0; S53: The solution formula for the pixel difference D is: D = y - y0. The unit of the pixel difference D is pix, where y is the remaining vertical pixel values in the set of contour information K where the vertical pixel value y0 is located.

2. The conveyor belt thickness measurement method according to claim 1, characterized in that The structured light bands are a pair of one-dimensional laser beams projected onto the upper and lower surfaces of the conveyor belt and located in the same cross-section, and the one-dimensional laser beams cover the entire width of the conveyor belt.

3. The conveyor belt thickness measurement method according to claim 1, characterized in that, It also includes the S6 adaptive obstacle avoidance step. The adaptive obstacle avoidance step includes the following steps: S61: Perform ultrasonic detection on the front, rear, and upper parts of the conveyor belt respectively. If an obstacle is found on the conveyor belt, go to S62; otherwise, jump to S1; S62: Generate the obstacle avoidance signal, and the conveyor belt thickness measuring device responds to the obstacle avoidance signal to adjust the working pose and perform obstacle avoidance.

4. A conveyor belt thickness measuring device, characterized in that, Adopt the conveyor belt thickness measurement method described in any one of claims 1-3, including arrangement frames arranged on both sides of the conveyor belt, and an image capture device, a specific point thickness acquisition device, a lateral coordinate capture device and a control module arranged on the arrangement frames; the image capture device includes a linear laser generator and an industrial camera arranged in pairs with the conveyor belt as the center, the linear laser generator is arranged on the arrangement frame and is used for projecting a structured light band on the conveyor belt, and the industrial camera is used for acquiring a photo of the conveyor belt with the structured light band. The specific point thickness acquisition device is movably matched with the arrangement frame along the width direction of the conveyor belt, and the specific point thickness acquisition device is used for acquiring the thickness information of the conveyor belt. The lateral coordinate capture device is used for capturing the lateral coordinate information of the specific point thickness acquisition device. The control module is electrically connected to the industrial camera, the specific point thickness acquisition device and the lateral coordinate capture device respectively, and is used for processing the photo, the thickness information and the lateral coordinate information, and calculating and outputting the full-section thickness information.

5. The conveyor belt thickness measuring device according to claim 4, characterized in that, It further includes an obstacle avoidance device. The obstacle avoidance device includes a pair of obstacle avoidance components symmetrically arranged on the arrangement frame with the conveyor belt as the center. The obstacle avoidance component includes a lateral mounting frame, an obstacle detection component, a servo motor group and a pair of longitudinal electric telescopic cylinders. The pair of longitudinal electric telescopic cylinders are respectively arranged on the arrangement frame along the vertical direction and are respectively located on both sides of the conveyor belt. The lateral mounting frame is horizontally arranged and is connected between the telescopic ends of the pair of longitudinal electric telescopic cylinders. The obstacle detection component is arranged on the lateral mounting frame. The fixed end of the servo motor group is arranged on the arrangement frame. The industrial camera is arranged on the arrangement frame through the servo motor group, and the industrial camera is arranged at the telescopic end of the servo motor group. The obstacle detection component, the servo motor group and the pair of longitudinal electric telescopic cylinders are all electrically connected to the control module.

6. The conveyor belt thickness measuring device according to claim 4, characterized in that The specific point thickness acquisition device includes a pair of displacement lead screws and displacement sensors arranged in pairs with the conveyor belt as the center. The displacement lead screws are arranged on a placement frame, and the displacement sensors are arranged on the mobile end of the displacement lead screws. The displacement lead screws are used for driving the displacement sensors to move along the width direction of the conveyor belt.

7. The conveyor belt thickness measuring device according to claim 6, wherein, The lateral coordinate capture device includes an ultrasonic sensor arranged on one side of the conveyor belt. The ultrasonic sensor is arranged on the arrangement frame. The ultrasonic sensor is electrically connected to the control module and is used for detecting the position of the displacement sensor and sending the lateral coordinate information to the control module.

8. A conveyor, characterized in that, Include the conveyor belt thickness measurement device described in any one of claims 4 to 7 above.

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