Surface shape measurement apparatus, surface shape measurement method, and belt management method

Abstract

A surface shape measurement apparatus (10) measures the surface shape of a belt driven by a driving means and comprises: a belt surface measurement device (12) for measuring the surface shape of the belt by imaging, with a camera (42), laser light with which the belt is irradiated; a control device (13) for computing the surface shape of the belt on the basis of measurement data on the measured surface shape of the belt; and a measurement condition analysis device (16) for determining a measurement condition for the belt surface measurement device on the basis of the luminance of the laser light with which the belt is irradiated and the luminance around the laser light.

Description

Surface profile measuring device, surface profile measuring method, and belt management method

[0001] The present disclosure relates to a surface profile measuring device, a surface profile measuring method, and a belt management method.

[0002] A belt conveyor is a known conveying device for conveying materials such as raw materials. The belt is driven by a pair of pulleys, and the thickness of the belt must be controlled to prevent the belt from breaking.

[0003] For example, Patent Documents 1 and 2 disclose a device for measuring the thickness of a conveyor belt by a light cutting method using a line-shaped laser beam to measure the unevenness of the surface of the conveyor belt.

[0004] JP 2017-32346 A JP 2020-76767 A

[0005] The devices disclosed in Patent Documents 1 and 2 require manual adjustment of measurement conditions, such as the brightness of the laser light, to suit the surrounding environment when measuring the surface shape of a conveyor belt using a laser light. However, it is not practical to manually adjust the measurement conditions of devices installed on multiple belt conveyors installed indoors and outdoors every time the surrounding environment changes, making it difficult to continue measuring the surface shape of a conveyor belt under appropriate measurement conditions while it is in operation.

[0006] In view of the above circumstances, an object of the present disclosure is to provide a surface profile measuring device, a surface profile measuring method, and a belt management method that can automatically determine belt measurement conditions according to the ambient brightness.

[0007] (1) A surface profile measuring device according to one embodiment of the present disclosure is a surface profile measuring device that measures the surface profile of a belt driven by a driving means, and includes: a belt surface measuring device that measures the surface profile of the belt by capturing an image of a laser beam irradiated onto the belt with a camera; a control device that calculates the surface profile of the belt based on measurement data of the measured surface profile of the belt; and a measurement condition analysis device that determines measurement conditions for the belt surface measuring device based on the brightness of the laser beam irradiated onto the belt and the brightness of the surrounding area of ​​the laser beam.

[0008] (2) As an embodiment of the present disclosure, in (1), the measurement condition analysis device determines an exposure time of the camera as the measurement condition.

[0009] (3) As an embodiment of the present disclosure, in (2), the measurement condition analysis device determines an exposure time of the camera so that the luminance of the laser light is a predetermined ratio to the luminance of the surrounding area of ​​the laser light.

[0010] (4) As one embodiment of the present disclosure, in (3), the predetermined ratio is equal to or greater than 2 times and equal to or less than 4 times.

[0011] (5) As one embodiment of the present disclosure, in any one of (1) to (4), the belt is wound around a pulley serving as the driving means, and the belt surface measuring device measures the surface shape of the belt at a portion where the belt contacts the pulley.

[0012] (6) As an embodiment of the present disclosure, in (5), the control device measures the surface shape of the pulley together with the belt, and calculates the surface shape of the belt based on the height of the pulley.

[0013] (7) A surface shape measuring method according to one embodiment of the present disclosure is a surface shape measuring method for measuring the surface shape of a belt driven by a driving means, the method including: a belt surface measuring device measuring the surface shape of the belt by capturing an image of a laser beam irradiated onto the belt with a camera; calculating the surface shape of the belt based on measurement data of the measured surface shape of the belt; and determining measurement conditions for the belt surface measuring device based on the brightness of the laser beam irradiated onto the belt and the brightness of the surrounding area of ​​the laser beam.

[0014] (8) A belt management method according to an embodiment of the present disclosure manages the belt based on the surface shape of the belt calculated by the surface shape measurement method of (7).

[0015] According to the present disclosure, it is possible to provide a surface profile measuring device, a surface profile measuring method, and a belt management method that can automatically determine belt measurement conditions according to the ambient brightness.

[0016] FIG. 1 is a diagram illustrating an example configuration of a surface profile measuring device according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of measuring the surface profile of a conveyor belt using a belt surface measuring device. FIG. 3A is a front view illustrating the configuration of the belt surface measuring device. FIG. 3B is a side view illustrating the configuration of the belt surface measuring device. FIG. 4A is a diagram illustrating an example image of the luminance of a laser beam (laser bright line luminance) and the luminance of the surroundings (background luminance). FIG. 4B is a diagram illustrating the relationship between the magnitude of the laser bright line luminance relative to the background luminance and the exposure time. FIG. 4C is a diagram illustrating a case where the laser bright line luminance is too high relative to the background luminance. FIG. 5 is a flowchart illustrating an example process of a surface profile measuring method according to an embodiment of the present disclosure. FIG. 6A is a diagram illustrating a laser bright line luminance that is less than twice the background luminance. FIG. 6B is a diagram illustrating a laser bright line luminance that is at least two times but not more than four times the background luminance. FIG. 6C is a diagram illustrating a laser bright line luminance that is more than four times the background luminance.

[0017] Hereinafter, a surface profile measuring device, a surface profile measuring method, and a belt management method according to an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, identical or corresponding parts are designated by the same reference numerals. In the description of this embodiment, the description of identical or corresponding parts will be omitted or simplified as appropriate.

[0018] <Surface Profile Measuring Apparatus> FIG. 1 shows an example of the configuration of a surface profile measuring apparatus 10 according to this embodiment. FIG. 2 shows how the belt surface measuring device 12 of the surface profile measuring apparatus 10 measures the surface profile of a conveyor belt 30. The surface profile measuring apparatus 10 measures the surface profile of a belt driven by a driving means. In this embodiment, the surface profile of the conveyor belt 30 wound around a pulley 20 (see FIG. 2) serving as the driving means is measured. The conveyor belt 30 is an example of a belt, and is a belt of a belt conveyor that carries and moves conveyed objects in the traveling direction. Here, the traveling direction is the direction in which the belt moves due to the driving force from the driving means. In this embodiment, the traveling direction is also referred to as the conveying direction. The conveying direction is the direction in which conveyed objects loaded on the surface 31 of the conveyor belt 30 move while in operation. The width direction is the short side direction of the conveyor belt 30, and is a direction perpendicular to the conveying direction on the surface 31 of the conveyor belt 30.

[0019] In a belt conveyor, it is necessary to manage the thickness of the conveyor belt 30 so that the conveyor belt 30 does not break. The thickness of the conveyor belt 30 can be managed by calculating the thickness of the conveyor belt 30 from the surface profile measured by the surface profile measuring device 10. Here, the surface profile refers to the shape including the irregularities of the surface 31 of the conveyor belt 30. For example, a portion of the surface 31 of the conveyor belt 30 that is recessed from the surrounding area can indicate that the thickness of the conveyor belt 30 is thinner than the surrounding area.

[0020] 1 , a surface profile measuring apparatus 10 according to this embodiment includes a belt surface measuring device 12, a control device 13, and a measurement condition analyzing device 16. The belt surface measuring device 12 includes an irradiation unit 40 and a camera 42. The control device 13 includes a calculation device 14 and a surface profile analyzing device 15. In another configuration example, the measurement condition analyzing device 16 may be included in the control device 13.

[0021] The belt surface measuring device 12, the control device 13, and the measurement condition analyzing device 16 are connected by a network such as a LAN (Local Area Network), and may be able to send and receive information obtained by measurement (measurement data).

[0022] 2, the conveyor belt 30, which is the object of measurement by the surface profile measuring device 10, is wound around a pulley 20. When the pulley 20 rotates, the conveyor belt 30 moves, and an object placed on the surface 31 can be moved. Here, the surface 31 of the conveyor belt 30 is the surface (outer surface) opposite to the surface of the conveyor belt 30 facing the pulley 20 (inner surface).

[0023] <Belt Surface Measuring Device> In this embodiment, the belt surface measuring device 12 is a non-contact measuring device that measures the surface shape of the conveyor belt 30 without coming into contact with the conveyor belt 30. The belt surface measuring device 12 may perform measurements only while the pulley 20 and the conveyor belt 30 are rotating, or may perform measurements continuously regardless of whether they are rotating or not.

[0024] FIG. 3A is a front view illustrating the configuration of the belt surface measuring device 12. FIG. 3B is a side view illustrating the configuration of the belt surface measuring device 12. In this embodiment, the belt surface measuring device 12 is a laser light cutting type device and includes an irradiation unit 40 that irradiates laser light 41 and a camera 42 that captures an image (moving image) including the laser light 41 irradiated onto the conveyor belt 30. The belt surface measuring device 12 measures the surface shape of the conveyor belt 30 by using the camera 42 to capture the laser light 41 irradiated onto the conveyor belt 30 from the irradiation unit 40. Here, in this embodiment, the belt surface measuring device 12 can measure the surface shape of the conveyor belt 30 over the entire width direction of the conveyor belt 30 by irradiating the conveyor belt 30 and the pulley 20 with a linear laser light 41.

[0025] The belt surface measuring device 12 measures the surface shape of the conveyor belt 30 at the portion where the conveyor belt 30 contacts the pulley 20. To this end, the belt surface measuring device 12 is installed in a position where it can irradiate the conveyor belt 30 with a laser beam 41, for example, directly above the pulley 20, obliquely above, or directly to the side. The belt surface measuring device 12 may be configured to be held near the pulley 20 by a holding member installed on the ground, for example. The belt surface measuring device 12 may also be configured to be held on the ceiling above the pulley 20. To accurately measure the thickness direction of the conveyor belt 30, the belt surface measuring device 12 is installed so that the irradiation direction of the laser beam 41 passes through the center 22 of the pulley 20. Because the belt surface measuring device 12 measures the surface shape of the conveyor belt 30 at the portion where the conveyor belt 30 contacts the pulley 20, the conveyor belt 30 does not shake up and down, and the conveyor belt 30 can be measured in a stable position. In this way, the belt surface measuring device 12 performs measurements to obtain measurement data (moving image data) of the surface shape, including the irregularities, of the conveyor belt 30. Here, the angle θ shown in Fig. 3B is the angle formed by the imaging direction of the camera 42 with respect to the laser light 41, and the camera 42 is positioned so that the irregularities of the conveyor belt 30 are captured as steps in the image. The value of the angle θ is not particularly limited, but is 18° as an example.

[0026] <Control Device> The control device 13 calculates the surface shape of the conveyor belt 30 based on measurement data of the measured surface shape of the conveyor belt 30. In this embodiment, the control device 13 calculates the surface shape of the conveyor belt 30 based on measurement data (moving image data) measured by the belt surface measuring device 12. The control device 13 is configured to include a calculation device 14 and a surface shape analysis device 15.

[0027] The calculation device 14 calculates three-dimensional distance data of the conveyor belt 30 from the measurement data (moving image data) of the belt surface measuring device 12. The calculation device 14 may be configured to include a processor that performs calculations and a storage unit that stores data used in the calculations (e.g., measurement data of the surface shape). The calculation device 14 may be, for example, a computer. The processor may be, for example, a general-purpose processor or a dedicated processor specialized for a specific process, but is not limited to these and may be any processor. The storage unit is one or more memories. Here, in this embodiment, the calculation device 14 is provided within the belt surface measuring device 12.

[0028] The surface profile analyzer 15 removes noise from the three-dimensional distance data of the conveyor belt 30 calculated by the calculator 14, and calculates the thickness of the conveyor belt 30 as the surface profile of the conveyor belt 30. Here, the noise is, for example, an error in the surface profile caused by the tilt and eccentricity of the axis of the pulley 20. Furthermore, when calculating the thickness of the conveyor belt 30, the surface profile analyzer 15 calculates the thickness of the conveyor belt 30 by using the height of the pulley 20 as a reference, that is, by taking the difference between the surface position of the conveyor belt 30 and the surface position of the pulley 20.

[0029] Like the arithmetic device 14, the surface profile analysis device 15 may be configured to include a processor that executes calculations and a storage unit that stores data used in the calculations (e.g., measurement data of the surface profile). The surface profile analysis device 15 may be, for example, a computer. The processor may be, for example, a general-purpose processor or a dedicated processor specialized for a specific process, but is not limited to these and may be any processor. The storage unit is one or more memories. Here, in this embodiment, the surface profile analysis device 15 is provided outside the belt surface measuring device 12.

[0030] Here, the control device 13 may store in a storage unit one or more programs used to control the operation of the surface profile measuring device 10. When the program stored in the storage unit is read by the processor of the control device 13, it may cause the control device 13 to function as the arithmetic device 14 and the surface profile analyzing device 15. For example, in a configuration in which the control device 13 further includes a measurement condition analyzing device 16, when the program is read by the processor of the control device 13, it may cause the control device 13 to function as the arithmetic device 14, the surface profile analyzing device 15, and the measurement condition analyzing device 16.

[0031] <Measurement Condition Analysis Device> The measurement condition analysis device 16 determines the measurement conditions of the belt surface measuring device 12 based on the brightness of the laser light 41 irradiated onto the conveyor belt 30 by the irradiation unit 40 of the belt surface measuring device 12 and the brightness of the area surrounding the laser light 41. In this embodiment, the measurement condition analysis device 16 determines the exposure time of the camera 42 as the measurement condition of the belt surface measuring device 12. The brightness of the area surrounding the laser light 41 includes the brightness of the area of ​​the conveyor belt 30 that is not irradiated with the laser light 41. Here, the exposure time of the camera 42 is the time during which the image sensor of the camera 42 is exposed to the laser light 41 when capturing an image. The measurement condition analysis device 16 may determine the exposure time of the camera 42 and the measurement frequency of the camera 42 (i.e., further the measurement frequency of the camera 42). The measurement frequency of the camera 42 is the interval between images captured by the camera 42. In this embodiment, the measurement condition analysis device 16 is described as determining the exposure time and measurement frequency of the camera 42. Generally, a longer exposure time of the camera 42 results in a lower measurement frequency, and a shorter exposure time of the camera 42 results in a higher measurement frequency. The belt surface measuring device 12 takes continuous photographs and stores measurement data (moving image data) according to the exposure time and measurement frequency of the camera 42 determined by the measurement condition analysis device 16. The measurement condition analysis device 16 may be configured with a processor that performs calculations and a memory unit that stores data used in the calculations. The measurement condition analysis device 16 may be, for example, a computer. The processor may be, for example, a general-purpose processor or a dedicated processor specialized for specific processing, but is not limited to these and may be any processor. The memory unit is one or more memories.

[0032] 4A to 4C are diagrams illustrating a method for determining the exposure time of the camera 42. FIG. 4A illustrates an example of an image of the luminance of the laser light 41 (laser bright line luminance) and the luminance of the surroundings (background luminance). If the measurement condition analysis device 16 is equipped with a display, an image (moving image) such as that shown in FIG. 4A may be displayed on the display. In the image, the brightness of the portion of the surface 31 of the conveyor belt 30 that is not irradiated with the laser light 41 is the background luminance. In the image, the brightness of the portion irradiated with the laser light 41 is the laser bright line luminance, and the difference in luminance may be shown, for example, using a grayscale. For example, the luminance may be displayed in 256 gradations. In the example of FIG. 4A, the laser light 41 is irradiated onto the conveyor belt 30 and the pulley 20, and the laser bright line luminance has a step at the boundary between them, which is shown as "laser bright line luminance (belt)" and "laser bright line luminance (pulley)," respectively. The reference line is a virtual line that indicates the position where the luminance distribution is measured, and in this embodiment, one reference line is provided at the center in the width direction of the conveyor belt 30 and the pulley 20. Here, the position of the reference line is not limited to the center, and multiple reference lines may be provided, and the luminance distribution may be determined by statistical values ​​(e.g., average values) of the luminance at the multiple reference lines.

[0033] FIG. 4B illustrates the relationship between the magnitude of the laser bright line brightness relative to the background brightness and the exposure time. The three graphs in FIG. 4B show the laser bright line brightness relative to the surrounding brightness (background brightness) as 1. The laser bright line brightness and background brightness are measured at the position of the reference line. In the left graph, the relative brightness value of the laser bright line brightness is 2. In the center graph, the relative brightness value of the laser bright line brightness is 3. In the right graph, the relative brightness value of the laser bright line brightness is 4. The background, which is not irradiated with laser light 41, has low brightness and reflects the brightness of the measurement location. For example, the background brightness corresponds to the light from the lighting fixture at night and to the sunlight during the day, but also varies depending on the weather. Here, the laser bright line brightness irradiated with laser light 41 is sufficiently bright and brighter than the background regardless of the time of day.

[0034] The measurement condition analyzer 16 determines the exposure time of the camera 42 so that the luminance of the laser light 41 (laser bright line luminance) is a predetermined ratio to the luminance of the surroundings of the laser light 41 (background luminance), i.e., so that the relative luminance value is within a predetermined range. The predetermined ratio is determined depending on the performance of the camera 42, but as an example, as shown in FIG. 6B, it is preferably 2 times or more and 4 times or less (200% or more and 400% or less). The predetermined ratio is more preferably 3 times or more and 4 times or less (300% or more and 400% or less). When the luminance of the laser bright line is less than 2 times the luminance of the background (less than 200%), the difference with the background luminance is too small, as shown in FIG. 6A, making it impossible to measure the laser light 41. Furthermore, as shown in FIG. 4C, when the luminance of the laser bright line is more than 4 times the luminance of the background (more than 400%), the laser light 41 is too strong, and the periphery of the bright line of the laser light 41 becomes bright and blurred (FIG. 6C). In this case, the bright and blurred area will also be measured, making accurate measurement difficult.

[0035] Here, the measurement conditions of the belt surface measuring device 12 determined by the measurement condition analyzer 16 are not limited to the exposure time of the camera 42, but may also be the measurement frequency of the camera 42 or the intensity of the laser light 41 irradiated from the irradiation unit 40. As with the exposure time of the camera 42, the measurement frequency of the camera 42 or the intensity of the laser light 41 irradiated from the irradiation unit 40 is also adjusted so that the luminance of the laser light 41 (luminance of the laser bright line portion) becomes a predetermined ratio to the luminance around the laser light 41 (luminance of the background portion).

[0036] However, the intensity of the laser light 41 emitted from the irradiation unit 40 is generally determined by the performance of the belt surface measuring device 12. Therefore, it is preferable that the measurement condition analysis device 16 adjusts the exposure time of the camera 42 that captures the laser light 41 rather than adjusting the laser light 41 itself. The measurement condition analysis device 16 adjusts the exposure time to set the laser line brightness to a predetermined ratio relative to the background brightness. Referring to FIG. 4B, the case where the laser line brightness is three times the background brightness (center graph) is used as a reference. Shortening the exposure time of the camera 42 of the belt surface measuring device 12 reduces the laser line brightness as shown in the left graph. Further shortening the exposure time makes the laser line brightness less than twice the background brightness. Increasing the exposure time of the camera 42 of the belt surface measuring device 12 increases the laser line brightness as shown in the right graph. Further increasing the exposure time makes the laser line brightness more than four times the background brightness (see FIG. 4C). Here, the predetermined ratio is assumed to be greater than two and less than four times. When the brightness of the laser bright line portion is less than twice the brightness of the background portion, the measurement condition analysis device 16 adjusts the exposure time of the camera 42 to be longer so that the ratio is a predetermined ratio. In this case, the measurement condition analysis device 16 may further adjust the measurement frequency of the camera 42 to be lower. Furthermore, when the brightness of the laser bright line portion is more than four times the brightness of the background portion, the measurement condition analysis device 16 adjusts the exposure time of the camera 42 to be shorter. In this case, the measurement condition analysis device 16 may further adjust the measurement frequency of the camera 42 to be higher.

[0037] As described above, the measurement condition analyzer 16 calculates the background luminance and the laser bright line luminance from the moving image measured by the belt surface measuring device 12, and determines the exposure time of the camera 42 so that the laser bright line luminance is a predetermined ratio to the background luminance. The measurement condition analyzer 16 outputs the determined exposure time of the camera 42 to the belt surface measuring device 12, and the belt surface measuring device 12 performs measurement using that exposure time. In this manner, measurement conditions such as the luminance of the laser light 41 are automatically adjusted to suit the surrounding environment. The measurement condition analyzer 16 may also determine the measurement frequency of the camera 42 based on the determined exposure time of the camera 42. In this embodiment, there is one belt surface measuring device 12. Therefore, the measurement frequency of the camera 42 can be calculated as the reciprocal of the exposure time of the camera 42. For example, if the determined exposure time of the camera 42 is 500 μs, the measurement frequency of the camera 42 is 2000 Hz (1 second divided by 500 μs).

[0038] <Surface Profile Measuring Method> FIG. 5 is a flowchart showing an example of processing in a surface profile measuring method executed by the surface profile measuring apparatus 10 according to this embodiment.

[0039] The belt surface measuring device 12 measures the surface shape of the conveyor belt 30 (step S1). At this time, the exposure time of the camera 42 is set to a predetermined initial value or a performance value from the previous measurement (previous value).

[0040] The measurement condition analyzer 16 determines the ratio of the laser bright line luminance to the background luminance from the measurement data of the belt surface measuring device 12 (step S2).

[0041] If the ratio of the laser line brightness to the background brightness is less than two times, the measurement condition analysis device 16 increases the exposure time of the camera 42 (step S3). The measurement condition analysis device 16 may further adjust the measurement frequency of the camera 42 to decrease it.

[0042] When the ratio of the laser line brightness to the background brightness is between 2 and 4 times, the measurement condition analysis device 16 does not change the exposure time of the camera 42 (step S4). At this time, the measurement condition analysis device 16 also does not change the measurement frequency of the camera 42.

[0043] If the ratio of the laser line brightness to the background brightness is greater than four times, the measurement condition analysis device 16 shortens the exposure time of the camera 42 (step S5). The measurement condition analysis device 16 may further adjust the measurement frequency of the camera 42 to increase it.

[0044] After steps S3 and S5, the measurement condition analyzer 16 re-evaluates the ratio of the laser bright line luminance to the background luminance from the measurement data of the belt surface measuring device 12 (step S2). The measurement condition analyzer 16 re-evaluates the ratio of the laser bright line luminance to the background luminance until the ratio is between two and four times the background luminance (step S2). If the ratio is between two and four times the background luminance in the re-evaluation, the measurement condition analyzer 16 does not change the exposure time of the camera 42 (step S4). At this time, the measurement condition analyzer 16 also does not change the measurement frequency of the camera 42.

[0045] The measurement condition analysis device 16 outputs the determined exposure time of the camera 42 to the belt surface measurement device 12, and the measurement conditions are automatically adjusted so that the belt surface measurement device 12 performs measurement using that exposure time. The automatic adjustment of the measurement conditions may be performed, for example, every hour or every two hours to reflect changes in brightness at the measurement location.

[0046] The belt surface measuring device 12 performs measurement using the exposure time determined by the measurement condition analyzing device 16. The computing device 14 calculates three-dimensional distance data of the conveyor belt 30 from the measurement data (moving image data) of the belt surface measuring device 12 (step S6).

[0047] Steps S1 to S6 are repeatedly executed until measurement data for a predetermined length (for example, two revolutions of the conveyor belt 30) is obtained (NO in step S7). However, if it is clear that the laser bright line luminance is at a predetermined ratio (two times or more and four times or less) to the background luminance, such as when not much time has passed since the automatic adjustment was executed, steps S2 to S5 of the repeated process may be omitted.

[0048] When measurement data of a predetermined length is obtained (YES in step S7), the calculation device 14 combines the calculated three-dimensional distance data (step S8).

[0049] The surface profile analyzer 15 removes noise from the combined three-dimensional distance data of the conveyor belt 30 and calculates the thickness of the conveyor belt 30 (step S9). As described above, the noise is an error in the surface profile caused by, for example, the tilt and eccentricity of the axis of the pulley 20, and may be calculated by a known method. In this embodiment, the control device 13 measures the surface profile of the pulley 20 together with the conveyor belt 30, and calculates the surface profile of the conveyor belt 30 based on the height of the pulley 20.

[0050] <Belt Management Method> Using the above-described surface profile measurement method, the conveyor belt 30 can be managed (monitored) based on the calculated surface profile of the conveyor belt 30. The surface profile measuring device 10 determines whether the thickness of the conveyor belt 30 is sufficient, for example, based on the calculated surface profile of the conveyor belt 30. If the surface profile measuring device 10 determines that the thickness is insufficient, it can notify an operator of an abnormality in the conveyor belt 30 or stop the conveyor belt 30. In this way, by managing the conveyor belt 30 based on the calculated surface profile of the conveyor belt 30, it becomes possible to accurately detect abnormalities in the conveyor belt 30 and to respond to the abnormality early.

[0051] As described above, the surface profile measuring device 10 and surface profile measuring method according to the present embodiment determine the exposure time of the camera 42 based on the brightness of the laser light 41 irradiated onto the belt and the brightness of the surrounding environment, thereby automatically determining the belt measurement conditions according to the brightness of the surrounding environment. This makes it possible to continue measuring the belt surface profile under appropriate measurement conditions during operation, resulting in accurate measurement of the belt surface profile. Furthermore, the belt management method according to the present embodiment makes it possible to accurately determine the thickness of the conveyor belt 30, allowing the conveyor belt 30 to be managed to prevent breakage or other problems.

[0052] Conventionally, because the ambient brightness changes depending on the irradiation environment (measurement location) of the laser light 41 and the time of measurement, it was necessary to manually adjust the exposure time of the camera 42 each time. According to the method of this embodiment, it is no longer necessary to manually adjust the measurement conditions of the surface profile measuring device 10 at multiple different measurement locations, and it is possible to automatically adjust the brightness of the laser light 41 to an appropriate brightness.

[0053] Furthermore, even if the ambient brightness changes during measurement, the exposure time of the camera 42 can be adjusted in real time based on the ratio of the brightness of the laser bright line to the brightness of the background, thereby improving the accuracy of measuring the surface shape of the conveyor belt 30.

[0054] Although the embodiments of the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art would easily be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, functions included in each component or step (process) can be rearranged so as not to cause logical inconsistencies, and multiple components or steps can be combined or divided into one. The embodiments of the present disclosure can also be realized as a program executed by a processor included in an apparatus or a storage medium on which a program is recorded. It should be understood that these are also included within the scope of the present disclosure.

[0055] <Other Embodiments> In the above embodiment, the case where there is one belt surface measuring device 12 has been described, but there may be two or more belt surface measuring devices 12. For example, when there are two belt surface measuring devices 12, they are lined up in the width direction of the conveyor belt 30, and one of the two belt surface measuring devices 12 measures the surface shape of the right half of the conveyor belt 30 in the width direction, and the other measures the surface shape of the left half.

[0056] Even when there are two belt surface measuring devices 12, the method for determining the exposure time of the camera 42 and the method for automatic adjustment are the same as in the case of one device described above. However, the method for determining the measurement frequency of the camera 42 is different from the case of one device described above.

[0057] When two belt surface measuring devices 12 are used, it is preferable to provide a non-irradiation time of 50 μs to prevent interference between the laser beams 41 of the two belt surface measuring devices 12 arranged in the width direction of the conveyor belt 30. When the exposure time of one camera 42 is 500 μs, the measurement frequency of one camera 42 is 909 Hz (1 second ÷ (500 μs + 50 μs + 500 μs + 50 μs)).

[0058] REFERENCE SIGNS LIST 10 Surface shape measuring device 12 Belt surface measuring device 13 Control device 14 Arithmetic device 15 Surface shape analyzing device 16 Measurement condition analyzing device 20 Pulley 22 Center 30 Conveyor belt 31 Conveyor belt surface 40 Irradiation unit 41 Laser light 42 Camera

Claims

1. A surface shape measuring device for measuring the surface shape of a belt driven by a driving means, comprising: a belt surface measuring device for measuring the surface shape of the belt by capturing an image of a laser light irradiated onto the belt with a camera; a control device for calculating the surface shape of the belt based on the measurement data of the measured surface shape of the belt; and a measurement condition analysis device for determining the measurement conditions of the belt surface measuring device based on the brightness of the laser light irradiated onto the belt and the brightness of the surrounding area of ​​the laser light.

2. The surface shape measuring device according to claim 1, wherein the measurement condition analyzing device determines an exposure time of the camera as the measurement condition.

3. The surface shape measuring device according to claim 2, wherein the measurement condition analyzing device determines the exposure time of the camera so that the brightness of the laser light is a predetermined ratio to the brightness of the surrounding area of ​​the laser light.

4. The surface shape measuring apparatus according to claim 3, wherein the predetermined ratio is greater than or equal to 2 times and less than or equal to 4 times.

5. A surface shape measuring device as described in any one of claims 1 to 4, wherein the belt is wound around a pulley serving as the driving means, and the belt surface measuring device measures the surface shape of the belt at the portion where the belt contacts the pulley.

6. The surface shape measuring device according to claim 5, wherein said control device measures the surface shape of said pulley together with said belt, and calculates the surface shape of said belt based on the height of said pulley.

7. A surface shape measuring method for measuring the surface shape of a belt driven by a driving means, comprising: a belt surface measuring device measuring the surface shape of the belt by photographing a laser light irradiated onto the belt with a camera; calculating the surface shape of the belt based on the measurement data of the measured surface shape of the belt; and determining measurement conditions for the belt surface measuring device based on the brightness of the laser light irradiated onto the belt and the brightness of the surrounding area of ​​the laser light.

8. A belt management method, comprising: managing the belt based on the surface shape of the belt calculated by the surface shape measuring method according to claim 7.

Images