System and method for measuring conveyor belt elongation

Abstract

A measurement system and method for measuring a conveyor belt. The measurement system includes a camera, a display screen, and a memory that can be housed in a handheld device, such as a smartphone. The camera takes a photo of a target surface of the belt. These photographs are processed and compared to a reference pattern stored in a database in a memory. And determining the longitudinal elongation of the belt through comparison. The percentage elongation of the nominal longitudinal pitch of the belt is displayed for replacement of the belt if necessary. The software program may also process image frames taken by the camera and display graphical indicators that guide a user to position the camera to an active position and orientation for accurate measurements.

Description

Technical Field

[0001] The present invention generally relates to a system and method for measuring the elongation of a conveyor belt, and more specifically to a system and method for measuring belt elongation using a camera. Background Technology

[0002] Modular plastic conveyor belts are widely used for transporting items in industrial plants. These belts consist of rigid plastic belt modules arranged in rows, with one or more modules connected end-to-end by hinged rods that extend through aligned orifices of staggered hinge elements at the hinge joints between adjacent rows. The distance between consecutive hinge joints is the belt's longitudinal pitch. New belts have a specified nominal longitudinal pitch. However, with use, the belt tends to stretch or elongate. Increased elongation of the belt's longitudinal pitch is due to thinning of the hinged rods or cam-shafting, or wallowing out of the orifices defining the hinge elements. When the belt elongation increases sufficiently beyond its nominal value, engagement with the conveyor's drive and driven sprockets is affected. In particular, the belt may intermittently climb onto and disengage from the sprocket teeth, which can reduce the belt's load-bearing capacity and may cause belt speed fluctuations and jostling of the transported items. Belt elongation as low as 3% of the belt's nominal longitudinal pitch can cause intermittent belt-sprocket disengagement.

[0003] Vision systems are commonly used to measure objects. In a typical setup for measurement, the camera is fixed at a known distance and orientation from the target to be measured. In this case, permanent calibration necessary for accurate measurement can be used. However, overcoming the calibration problem by establishing a fixed vision system is expensive and time-consuming. Summary of the Invention

[0004] One version of the belt measurement system includes a camera, a display screen, and a memory storing a reference pattern of repeating belt features on a target surface of a conveyor belt. Software is stored in the memory. When the software is selected to be run by a user, it executes program instructions in the memory to: (a) capture target image frames of the target surface generated by the camera when the user aims the camera at the target surface; (b) perform correlation between the reference pattern and these target image frames to identify the location of the repeating belt features within these target image frames; (c) determine the position of the camera relative to the target surface based on these correlations; (d) display graphic indicators on the display screen to guide the user to position the camera relative to the target surface in an effective position, enabling accurate measurement of the repeating belt features; and (e) when the camera is in an effective position relative to the target surface, measure the distances between these repeating belt features on the target surface as measurements based on these correlations.

[0005] Another version of the belt measurement system includes a handheld device comprising a camera, a display screen, and a memory storing a belt database comprising multiple reference patterns of repeating belt features on a target surface of multiple conveyor belts with different belt patterns. Software is stored in the memory. When the software is selected to be run by a user, it executes program instructions in the memory to: (a) capture target image frames of the target surface of the conveyor belt to be identified, generated by the camera when the user aims it at the target surface; (b) perform correlation between the multiple reference patterns and the repeating belt features in these target image frames to identify the belt pattern with the highest correlation; and (c) display the belt pattern with the highest correlation on the display screen.

[0006] A method for measuring a conveyor belt includes: (a) running software in a belt measurement system, the belt measurement system including a camera, a display screen, and a belt database stored in a memory; (b) aiming the camera at a target surface on the conveyor belt to capture a target image frame of the target surface. The software program executes program instructions in the memory to: (i) capture the target image frame of the target surface generated by the camera; (ii) correlate a reference pattern of repeating belt features on the target surface of the conveyor belt in the belt database with the target image frames to identify the location of the repeating belt features in the target image frames; (iii) determine the position of the camera relative to the target surface based on the correlations; (iv) display graphic indicators on the display screen to guide the user to position the camera relative to the target surface in an effective position, enabling accurate measurement of the repeating belt features; and (v) when the camera is in an effective position relative to the target surface, measuring the distance between the repeating belt features on the target surface as a measurement value based on the correlations. Attached Figure Description

[0007] Figure 1 This is an isometric view of a version of a measurement system used for conveyor belts.

[0008] Figure 2 It is possible Figure 1 A schematic diagram of the handheld device used in the measurement system.

[0009] Figure 3 It is as follows Figure 1 A target image frame captured by the measurement system in the image, showing a portion of the conveyor belt.

[0010] Figure 4 Is it like this? Figure 1 The reference pattern or markings for the conveyor belt in the diagram.

[0011] Figure 5 It was taken from a perspective that is not perpendicular to the target surface of the belt, such as... Figure 1 The target image frame of the conveyor belt in the image.

[0012] Figure 6 It was taken from a perspective perpendicular to the target surface of the belt. Figure 1 The target image frame of the conveyor belt in the image.

[0013] Figure 7 It is a description Figure 1 The flowchart of the operation of the measurement system.

[0014] Figures 8A to 8HThis depicts a version of a graphical indicator displayed to guide the user in correctly positioning and orienting the camera for accurate measurements.

[0015] Figures 9A to 9H A second version of the graphical indicator was depicted to guide the user in locating the camera.

[0016] Figures 10A to 10H It is the third version of the graphical indicator used to guide users in locating the camera.

[0017] Figure 11 It shows the use of Figure 10A The graphical indicators provide a clear display of measurements. Detailed Implementation

[0018] exist Figure 1 The diagram illustrates a conveyor belt measurement system. The belt measurement system includes a handheld device 20 that measures the conveyor belt 22. The handheld device 20 (e.g., as...) Figure 2 The smartphone 24 contains a camera 26 (on the flip side), a display screen 28, and a memory 30 (internal), which includes a program memory segment and a data memory segment. The camera 26 of the handheld device 20 is aimed by the user at a target surface 32 of the conveyor belt 22, such as the conveyor surface. A software program (such as a smartphone app) executing program steps stored in the program memory segment of the memory 30 captures a target image frame 34 of a portion of the target surface 32, as seen by the camera 26. Preferably, the camera 26 is held in a perfect position: (a) its lens is parallel to the target surface 32; that is, aimed perpendicular to the target surface; (b) the camera is oriented such that the target image frame is aligned with the longitudinal and lateral axes of the target surface; and (c) it is at a sufficient distance from the target surface so that the target image frame includes enough repeating belt features on the target surface for accurate measurement. However, it is nearly impossible to hold the camera 26 precisely in a perfect position. Therefore, it is only necessary to keep the camera in an effective position (distance from the target surface and orientation relative to the target surface), which allows the software program to locate the repeating belt features in the target image frame and transform the target image frame as needed by translating and rotating it around three axes to simulate a target image taken from a perfect position, thus enabling accurate measurements.

[0019] Initially, the filming was like... Figure 3The target image frame 36 is shown, in which the belt is skewed relative to the frame. While camera 26 continuously takes pictures, the software process these pictures and guides the user to orient and position the camera via graphical indicators on display screen 28, bringing the camera to an effective position close enough to the perfect position for accurate measurement of belt 22 based on the target image frame. Once camera 26 is in an effective position relative to target surface 32, the user holds the camera still for several seconds while the measurement is performed. The measurement results are then displayed on display screen 28.

[0020] Storing in the data storage segment of memory 30 is a belt database containing reference patterns 38 of repeating belt features. Figure 4 In the example, reference pattern 38 is an area on the target surface 32 of the belt that includes a portion of the belt's articulated joint, as will be seen in the plan view. In this case, reference pattern 38 is a segment of the articulated joint that is twice the lateral pitch of the belt's articulated element 39. The database may include more than one reference pattern representing other belt styles. If the database does include reference patterns for different belt styles, the user selects the target belt style to use the corresponding reference pattern.

[0021] The belt database may also include pattern data corresponding to each reference pattern. The pattern data may include the nominal longitudinal pitch P of the reference pattern that repeats the belt features. L and nominal lateral pitch P T ,like Figure 1 As shown. The pattern data may also, or alternatively, include the nominal lateral pitch P. T With the nominal longitudinal pitch P L The ratio R TL or its reciprocal R LT .

[0022] Additionally, the belt database can include individual visual processing settings for each reference pattern, such as high-pass and low-pass filter settings, image normalization settings, contrast settings, and brightness settings, to customize the processing of the target image frame. For example, other settings customized for each reference pattern may include minimum and maximum distances between the camera and the belt, zoom limits, and limits on camera rotation and yaw. For belt databases containing multiple reference patterns, a unique belt style identifier is stored in the database for each reference pattern.

[0023] The handheld device's camera 26 continuously captures images, for example, at a rate of 5 to 30 frames per second. This allows the software program to continuously update the display screen 28 with graphical indicators to guide the user in positioning the camera 26 in the effective position for accurate measurements. Although single-shot measurements are possible, using a single shot relies on the user positioning the camera 26 in the effective position relative to the target surface 32 of the belt 22. The final measurement, performed when the camera 26 is in the effective position, takes only about five seconds to process. It is also possible to measure whether the belt 22 is stationary or moving.

[0024] exist Figure 7 The diagram shows a flowchart indicating the steps of the measurement process. The first step is to select the pattern of the conveyor belt to be measured so that the software program can retrieve the appropriate reference pattern from memory. This step is unnecessary if the database contains only one reference pattern. The user aims the camera at the target surface of the belt, takes a photograph, and the software program captures a frame of the belt target image. Figure 5 As shown, the software program uses reference pattern 38 ( Figure 4 The repeating belt feature 40 or marker is associated with the target image frame to locate it in the target image frame 42. Since the earlier photographs may not have been taken by a camera in an effective position, but were incorrectly oriented and spaced out, making accurate measurement impossible, the image frame is characterized as a three-dimensional (3D) image, and the marker 40 is characterized as a 3D marker.

[0025] Figure 5 Target image frame 42 represents a 3D image captured by a camera at an angle tilted away from the target surface of the conveyor belt, perpendicular to its vertical direction. This is indicated by the convergence of dashed lines 44 along the Y-axis 46 away from the camera position at each articulation point of frame 42, passing through 3D markers 40. The X-axis 47 is orthogonal to the Y-axis 46 in the image plane. The Z-axis 48 is orthogonal to both the Y-axis 46 and the X-axis 47. By analyzing the dashed lines 44 passing through markers 40 along the articulation points and the dashed lines 45 passing through the markers from the articulation points to the articulation points, the software program determines the camera's position and orientation relative to the target surface of the belt. Figure 5 In the example target image frame 42, the camera orientation is tilted only around the X-axis. This is because the dashed line 45 is parallel to the X-axis, and the dotted line 44 converges along the Y-axis 46 away from the camera. Using this information, the software program can transform the stereoscopic 3D target image frame 42 into a format similar to... Figure 6 The two-dimensional (2D) planar view image frame 50 shown allows for accurate measurements. Alternatively or additionally, this information can be used to display graphical indicators that guide the user to correctly position the camera in the effective location. Through analysis... Figure 5 The information collected from marker 40 in target image frame 42 indicates that the camera rotates R around the X-axis 47.X To improve the view. In this example, the rotation R around the Y-axis 46 and Z-axis 48. Y R Z It is unnecessary. Similarly, in this example, translating T along the X-axis 47 and Y-axis 46 is unnecessary. X T Y It is also unnecessary for the camera to minimize the capture of the off-belt region in the target image frame.

[0026] After the positioning of the 3D marker 40 and the position and orientation of the camera have been determined, the software program can display camera positioning feedback in the form of graphical indicators. These indicators help guide the user to position and orient the camera to the effective location for accurate measurement. Figures 8A to 8H , Figures 9A to 9H and Figures 10A to 10H Examples of three versions of the graphic indicator are shown in the image.

[0027] Figures 8A to 8H The graphic indicators displayed on the screen include a pair of similar concentric stationary rectangles (or squares) 52, 54 and a movable quadrilateral 56. The orientation, size, and shape of the movable quadrilateral change with the orientation of the camera relative to the target surface of the belt and the distance from the target surface. When quadrilateral 56 is concentric with or sufficiently close to concentric with the two stationary rectangles 52, 54 and substantially located between them (e.g., ...), the camera moves towards the target surface. Figure 8A As shown, the target surface is framed relative to the camera for accurate measurement. Figures 8B to 8H The conditions of other cameras on the target surface are depicted. Figure 8B Guide the user to pan the camera along the X-axis. Figure 8C Guide the user to pan the camera along the Y-axis. Figure 8D Guide the user to translate the camera away from the target surface along the Z-axis. Figure 8E Guide the user to rotate the camera around the Z-axis. Figure 8F Guide the user to rotate the camera around the Y-axis. Figure 8G Guide the user to rotate the camera around the X-axis. Figure 8H Guide the user to translate the camera along the Z-axis, bringing it closer to the target surface. To further assist the user in positioning the camera effectively, quadrilateral 54 can be a dashed line as shown in the attached diagram, or it can be a different color than rectangles 52 and 54. For example, quadrilateral 56 could be red, and rectangles 52 and 54 could be black. And, for example, when the camera is in an effective position for accurate measurement (such as... Figure 8A When shown in the figure, the color of the red quadrilateral can change from red to green.

[0028] Figures 9A to 9HAn alternative version of the graphic indicator in the form of a stationary crosshair 60 and a guide crosshair 62 of fixed size is shown, the orientation and size of which vary with the orientation of the camera relative to the target surface of the belt and the distance from the target surface. Figures 9A to 9H The situation indicated and Figures 8A to 8H The situation depicted in each figure is the same. When the camera is positioned in an effective location for accurate measurement, the movable guide crosshair 62 coincides with or is sufficiently close to coinciding with the stationary crosshair in range and position, as shown in the figure. Figure 9A As shown. And with Figures 8A to 8H Similar to graphic indicators, color can be used as an aid. For example, a stationary crosshair can be black, and a leading crosshair can be red until the camera... Figure 9A It turns green when correctly positioned.

[0029] exist Figures 10A to 10H The image shows an example of a set of third alternative graphic indicators. They are also shown graphically. Figures 8A to 8H and Figures 9A to 9H The corresponding situation. This set of graphic indicators uses a similar... Figures 9A to 9H The system includes a stationary crosshair 70 and a guide crosshair 72. A stationary solid-filled circle 74 is concentric with the stationary crosshair 70. The movable guide crosshair 72 is concentric with a guide ellipse 76, the orientation, size, and eccentricity of which change with the camera's orientation relative to the target surface of the belt and its distance from the target surface. The eccentricity increases from 0 (for a circular ellipse, or a circle) to 1 (for a flattened degenerate ellipse). The eccentricity of the guide ellipse 76 is proportional to the camera's tilt away from the Z-axis, such as... Figure 10F and Figure 10G The graphic indicator indicates that when the camera is too far from the target area of ​​the belt, the guide ellipse 76 is located within the stationary circle 74, as shown. Figure 10D As shown. If the camera is too close to the target area of ​​the belt, the stationary circle 74 will be located within the guide circle 76, as... Figure 10H As shown. Color can also be used to assist the user in positioning the camera. For example, the stationary circle 74 can be pure black, the stationary crosshair 70 can have a black outline, and the guide ellipse 76 can be red with a white interior. The guide crosshair 72 can be red. And when the camera is positioned in a valid location for accurate measurement, the guide ellipse 76 is circular or sufficiently close to circular and lies within the boundary of the stationary circle 74, and its color, along with the guide crosshair 72, turns green, which then coincides with the stationary crosshair 70.

[0030] like Figure 7 As shown, the software program will then Figure 5The 3D target image frame 42 is transformed into a transformed 2D target image frame 50, wherein the transformed target image frame 50 is parallel to the target surface, such that the belt markings 40 are aligned with orthogonal rows and columns parallel to the X-axis 47 and Y-axis 46, as shown. Figure 6 As shown. In the transformed target image frame 50, the X-axis and Y-axis coordinates for marker positioning are determined in camera pixel units. Based on these coordinates, the software program calculates the percentage of longitudinal belt elongation E along the X-axis 47, as shown below. E = [R TL •(P LM / P TM ) - 1]•100%, Among them, P LM The longitudinal (X-axis) pitch of marker 40, measured in the transformed target image frame 50, is P. TM It is the lateral (Y-axis) pitch of the markers in the transformed target image frame, and R TL It is the ratio of the nominal lateral pitch to the nominal longitudinal pitch.

[0031] Because the camera is handheld, the measurement is susceptible to measurement noise. The software program can reduce this noise by basing the final measurement on the average of a series of individual measurements. Furthermore, the measurement error is calculated and displayed to provide the user with a quantitative measure of the reliability of the belt elongation measurement. The software program calculates the measurement error as a positive or negative predetermined multiple of the standard deviation σ of the most recent valid measurement. For example, a measurement error of ±3σ can be used. The number of valid measurements used to calculate the standard deviation is a value stored in the database settings.

[0032] In this example, using Figure 10A The graphical indicator displays the calculation results on the screen, such as... Figure 11 As shown, the display shows a graphic indicator 80, belt style 82, the longitudinal elongation percentage E of the conveyor belt, and measurement error 84. If the standard deviation or measurement error is greater than a predetermined percentage of the measured value, the measurement error 84 or the longitudinal elongation percentage E, or both, may be displayed in red or flashing to indicate a questionable elongation percentage value. If the standard deviation or measurement error is less than a predetermined percentage of the measured value, the measurement error 84 or the longitudinal elongation percentage E, or both, may be displayed in green to indicate a valid elongation percentage value. The graphic indicator 80 also qualitatively indicates the measurement error by the deviation of the guide cross 72 from the stationary cross 70. Based on the displayed values ​​of the belt longitudinal elongation percentage E and measurement error 84, the user can decide whether the conveyor belt should be replaced.

[0033] Although the belt measurement system has been described in detail with respect to exemplary versions, other versions and uses are possible. For example, the belt measurement system can be used to identify belt patterns by associating a target image frame of the belt with a library of reference image frames stored in memory, and selecting and displaying the belt pattern of the reference image frame with the highest correlation value above an acceptable predetermined threshold. Using similar measurement and correlation techniques, the software program can also detect broken or damaged belt modules or degraded target surfaces and alert the user by displaying a message on the screen. And, of course, colors and display effects other than those mentioned can be displayed to guide the user in positioning the camera for accurate measurement. Although all exemplary versions describe handheld devices, particularly smartphones, the system and method can also be used to establish a fixed camera measurement system for measuring belt elongation.

Claims

1. A belt measuring system, comprising: camera; Display screen; A memory containing a belt database, which includes reference patterns of repeating belt features on the target surface of a conveyor belt; A software program stored in memory, which executes program instructions in memory when selected by the user to: When the user aims the camera at the target surface, it captures a target image frame of the target surface generated by the camera; The reference pattern is correlated with these target image frames to identify the location of repeating belt features in these target image frames; The position of the camera relative to the target surface is determined based on these correlations; Graphical indicators are displayed on the screen to guide the user in positioning the camera relative to the target surface, enabling accurate measurement of the repeating belt feature. When the camera is in an effective position relative to the target surface, the distance between these repeating belt features on the target surface is measured as a measurement value based on these correlations.

2. The belt measuring system as described in claim 1, wherein, The belt database includes the nominal longitudinal pitch and nominal transverse pitch of these repeating belt features scaled according to the reference pattern, or the ratio of the nominal longitudinal pitch to the nominal transverse pitch, or vice versa.

3. The belt measuring system as described in claim 1, wherein, The belt database includes multiple reference patterns, each corresponding to a different belt style.

4. The belt measuring system as described in claim 3, wherein, The belt database includes belt style identifiers corresponding to each reference pattern.

5. The belt measuring system as described in claim 4, wherein, The software program identifies the belt pattern of the conveyor belt by performing correlation analysis between these target image frames and these reference patterns and displaying the belt pattern identifier associated with the reference pattern that has the highest correlation with these target image frames.

6. The belt measuring system as described in claim 3, wherein, The belt database includes pattern data corresponding to each reference pattern, wherein the pattern data corresponding to each reference pattern includes the nominal longitudinal pitch and nominal transverse pitch of repeating belt features scaled according to the reference pattern, or the ratio of the nominal longitudinal pitch to the nominal transverse pitch, or vice versa.

7. The belt measuring system as described in claim 3, wherein, The belt database includes visual processing settings corresponding to each reference pattern, used to customize the processing of these target image frames for each belt style.

8. The belt measuring system as described in claim 1, wherein, These graphic indicators provide feedback to the user by changing their appearance, guiding the user to move the camera relative to the target surface to an effective position for accurate measurement.

9. The belt measuring system as described in claim 1, wherein, The graphic indicators on the display screen include quadrilaterals whose orientation, size, and shape change as the camera's orientation relative to and distance from the target surface changes.

10. The belt measuring system as described in claim 9, wherein, These graphic indicators include a pair of fixed concentric rectangles, wherein the camera is in an effective position relative to the target surface so as to make accurate measurements when the quadrilateral is concentric with and between the pair of fixed concentric rectangles in the display screen.

11. The belt measuring system as claimed in claim 1, wherein, The graphic indicator in the display includes a guide crosshair, the orientation and size of which change with the orientation of the camera relative to the target surface and the distance from the target surface.

12. The belt measuring system as described in claim 11, wherein, These graphic indicators include a fixed crosshair, wherein the camera is in an effective position relative to the target surface so as to make accurate measurements when the guide crosshair coincides with the fixed crosshair.

13. The belt measuring system as described in claim 1, wherein, These graphic indicators include a guide ellipse whose orientation, size, and eccentricity vary with the camera's orientation relative to and distance from the target surface.

14. The belt measuring system as claimed in claim 13, wherein, These graphic indicators include a fixed circular ellipse, wherein the camera is in an effective position relative to the target surface to make accurate measurements when the guide ellipse is circular and coincides with the fixed circular ellipse.

15. The belt measuring system as claimed in claim 1, wherein, The software program measures the longitudinal pitch (P) of the repeating belt feature on the target surface based on these measurements. LM ) and the lateral pitch (P TM And calculate the longitudinal elongation percentage (E) of the conveyor belt, as shown below. E = [R TL •(P LM / P TM ) - 1)]•100%, Among them, R TL It is the ratio of the nominal transverse pitch to the nominal longitudinal pitch of the repeating belt feature.

16. The belt measuring system as described in claim 15, wherein, The software program calculates the standard deviation of a set of recent measurements, and when the standard deviation is a predetermined proportion of the measurements, displays the effective value of the longitudinal elongation percentage of the conveyor belt on the display screen.

17. The belt measuring system as claimed in claim 16, wherein, The software program calculates the measurement error as a positive or negative multiple of the standard deviation and displays the measurement error and the effective longitudinal elongation percentage of the conveyor belt on the display screen.

18. The belt measuring system as claimed in claim 16, wherein, The software program displays a graphical indicator on the screen that corresponds to the effective value of the longitudinal elongation percentage of the conveyor belt.

19. The belt measuring system as claimed in claim 1, wherein, The software program transforms these target image frames into transformed target image frames by rotation and translation as needed. These transformed target image frames are parallel to the target surface, such that the belt markers representing the location of the repeating belt feature are orthogonally aligned in rows and columns in these transformed target image frames.

20. The belt measuring system of claim 1, comprising a handheld device that houses the camera, the display, and the memory.

21. The belt measuring system as described in claim 20, wherein, The handheld device is a smartphone, and the software program is included in a smartphone app residing in the memory.

22. A method for measuring a conveyor belt, the method comprising: A software program is run in the belt measurement system, which includes a camera, a display screen, and a memory in which a belt database is stored. Aim the camera at the target surface on the conveyor belt to capture a target image frame of the target surface; The software program executes program instructions in memory as follows: Capture the target image frame of the target surface generated by the camera; A reference pattern of repeating belt features on the target surface of the conveyor belt in the belt database is correlated with these target image frames to identify the location of the repeating belt features in the target image frames; The position of the camera relative to the target surface is determined based on these correlations; Graphical indicators are displayed on the screen to guide the user in positioning the camera relative to the target surface, enabling accurate measurement of the repeating belt feature. When the camera is in an effective position relative to the target surface, the distance between these repeating belt features on the target surface is measured as a measurement value based on these correlations.

23. The method of claim 22, wherein, The software program measures the longitudinal pitch (P) of the repeating belt feature on the target surface based on these measurements. LM ) and the lateral pitch (P TM And calculate the longitudinal elongation percentage (E) of the conveyor belt, as shown below. E = [R TL •(P LM / P TM ) - 1)]•100%, Among them, R TL It is the ratio of the nominal transverse pitch to the nominal longitudinal pitch of the repeating belt feature.

24. The method of claim 23, wherein, The software program calculates the standard deviation of a set of recent measurements, and when the standard deviation is a predetermined proportion of the measurements, displays the effective value of the longitudinal elongation percentage of the conveyor belt on the display screen.

25. The method of claim 24, wherein, The software program calculates the measurement error as a positive or negative multiple of the standard deviation and displays the measurement error and the effective longitudinal elongation percentage of the conveyor belt on the display screen.

26. The method of claim 22, wherein, The software program transforms these target image frames into transformed target image frames by rotation and translation as needed. These transformed target image frames are parallel to the target surface, such that the belt markers representing the location of the repeating belt feature are orthogonally aligned in rows and columns in these transformed target image frames.

27. The method of claim 22, further comprising storing a plurality of reference patterns in the belt database, each reference pattern corresponding to a different belt style.

28. The method of claim 27, further comprising storing visual processing settings corresponding to each reference pattern in the belt database for customizing the processing of these target image frames for each belt style.

29. A belt measuring system, comprising: Handheld device, the handheld device comprising: camera; Display screen; The memory stores a belt database, which includes multiple reference patterns of repeating belt features on the target surface of multiple conveyor belts with different belt styles. A software program stored in memory, which executes program instructions in memory when selected by the user to: When the camera is aimed at the target surface by the user, it captures a target image frame of the target surface of the conveyor belt to be identified, generated by the camera. The multiple reference patterns are correlated with the repeating belt features in these target image frames to identify the belt pattern with the highest correlation. The belt style with the highest relevance is displayed on the screen.

30. The belt measuring system as described in claim 29, wherein, The software program executes program instructions to determine the position of the camera relative to these target surfaces based on these correlations, and displays graphic indicators on the display screen to guide the user to position the camera in an effective position relative to the target surface, enabling accurate measurement of these repeating belt features.

31. The belt measuring system as described in claim 29, wherein, The handheld device is a smartphone, and the software program is included in a smartphone app residing in the memory.

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