Belt conveyor management system and management method

Abstract

The management system 1 for the belt conveyor 30 that transports materials by belt includes a three-dimensional measuring device 10 that measures the three-dimensional position of the lowest surface 32A of the belt 32 and the height of the accumulated material 42 located below the lowest surface 32A, and a monitoring device 20 that monitors the height of the accumulated material 42 relative to the three-dimensional position of the lowest surface 32A of the belt 32 measured by the three-dimensional measuring device 10.

Description

Technical Field

[0001] The present disclosure relates to a management system and a management method for a belt conveyor that conveys a conveyed object by a belt.

Background Art

[0002] For example, iron ore or coal, which is the main raw material required in the ironmaking process, is imported by a bulk carrier, unloaded from the raw material quay by an unloader, and transported to the raw material yard by type or brand. The stacking of raw materials in the raw material yard is performed by a stacker. The stacker can travel on rails laid in the raw material yard, and drops raw materials from an in-machine belt conveyor on a boom that can be raised and lowered and rotated, and stacks them as a raw material pile in the yard. The discharge from the raw material yard is performed by a reclaimer. The reclaimer rotates a bucket wheel to cut out raw materials from the pile and discharges them to a discharge conveyor by the in-machine belt conveyor on the boom. Mobile machines such as stackers or reclaimers are configured to move along a ground conveyor, which is a belt conveyor that transports raw materials.

[0003] Defects of the belt conveyor include, for example, belt meandering, roller wear or rotation failure, belt breakage, or adhesion or deposition of raw materials or foreign substances. Many of the belt conveyors used together with stackers or reclaimers are installed close to the ground. Therefore, when dust accumulates, the accumulated dust contacts the return roller or the return belt, causing wear, heat generation, belt breakage, or roller rotation failure.

[0004] Abnormalities of the belt conveyor that conveys raw materials directly affect stable production at the ironworks. Therefore, inspection management of the belt conveyor is very important. However, because many of the belt conveyors are installed close to the ground, maintenance personnel need to bend down to inspect the belt conveyor. Also, a great deal of labor is required for the removal work of deposits. Improvement of the inspection management work of the belt conveyor is demanded.

[0005] Patent documents 1 and 2 propose a method for monitoring the temperature of conveyor rollers or accumulated material using temperature sensors. Patent document 3 also proposes a method for monitoring the height or temperature of accumulated material by attaching an image capturing device to a mobile device that moves along a conveyor. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2002-205813 [Patent Document 2] Japanese Patent Publication No. 2018-127333 [Patent Document 3] Patent No. 6809494 [Overview of the project] [Problems that the invention aims to solve]

[0007] The methods described in Patent Documents 1 and 2 only monitor the temperature of the deposit or the roller, and therefore cannot monitor the height of the deposit relative to the belt position. Furthermore, the method described in Patent Document 3 can detect contact between the deposit and the belt in advance by managing the distance between the conveyor belt and the deposit. However, because the image capture device is mounted at approximately the same height as the belt and the thin belt is photographed from the thickness direction, it is difficult to accurately detect the position of the belt.

[0008] In view of these circumstances, the purpose of this disclosure is to provide a belt conveyor management system and management method that can accurately monitor the height of the accumulated material relative to the three-dimensional position of the bottom surface of the belt by measuring the three-dimensional position of the bottom surface of the belt using a three-dimensional measuring device. [Means for solving the problem]

[0009] (1) A belt conveyor management system according to one embodiment of the present disclosure is a management system for a belt conveyor that transports objects by a belt. The belt conveyor management system includes a three-dimensional measuring device that measures the three-dimensional position of the lowest surface of the belt and the height of the deposits located below the lowest surface, and a monitoring device that monitors the height of the deposits relative to the three-dimensional position of the lowest surface of the belt measured by the three-dimensional measuring device.

[0010] (2) In the belt conveyor management system described in (1) above, the three-dimensional measuring device is configured to obtain distance or three-dimensional position by irradiating an object to be measured with electromagnetic waves and detecting the reflection thereof, and the electromagnetic waves may be light, millimeter waves, or microwaves.

[0011] (3) In the belt conveyor management system described in (2) above, the installation height of the three-dimensional measuring device may be set such that when the accumulated material reaches a height at which it is likely to come into contact with the lowest surface of the belt, the electromagnetic waves irradiated below the central axis of the measurement range reach the accumulated material.

[0012] (4) In the belt conveyor management system described in any one of (1) to (3) above, the three-dimensional measuring device may be positioned lower than the lowest surface of the belt and positioned such that the central axis of its measuring range is aligned substantially horizontally.

[0013] (5) In the belt conveyor management system described in any one of (1) to (3) above, the three-dimensional measuring device may be installed such that the central axis of the measuring range of the three-dimensional measuring device is tilted upward with respect to the horizontal at an angle less than or equal to the maximum angle. The maximum angle may be an angle calculated as the arctangent of the value obtained by dividing the allowable height difference between the height of the lowest surface of the belt and the height of the deposit by the width of the belt.

[0014] (6) In the belt conveyor management system described in any one of (1) to (5) above, the three-dimensional measuring device may be mounted on a mobile device that can travel along the belt conveyor in the raw material yard. Alternatively, the three-dimensional measuring device may be fixed to the ground, foundation, frame or support or the frame of the belt conveyor in the raw material yard.

[0015] (7) In the belt conveyor management system described in any one of (1) to (6) above, the monitoring device may calculate the difference between the height of the bottom surface of the belt and the height of the deposit, corresponding to each of the three-dimensional positions of the multiple locations on the bottom surface of the belt measured by the three-dimensional measuring device.

[0016] (8) In the belt conveyor management system described in any one of (1) to (7) above, the monitoring device may perform preprocessing to remove point cloud data caused by known structures based on the location and shape information of said structures.

[0017] (9) In the belt conveyor management system described in any one of (1) to (8) above, the monitoring device may estimate the height of the lowest surface of the belt by a histogram of the Y coordinate in a coordinate system in which the direction of movement of the lower belt is the X axis, the height direction from the lower belt toward the upper belt is the Y axis, and the width direction of the lower belt is the Z axis.

[0018] (10) In the belt conveyor management system described in (9) above, the monitoring device may calculate the height difference, which is the difference in the Y coordinate between the bottom surface and the surface of the deposit, for each point on the XZ plane in a coordinate system in which the direction of movement of the lower belt included in the belt is the X axis, the height direction from the lower belt toward the upper belt included in the belt is the Y axis, and the width direction of the lower belt is the Z axis, and display the height difference or the monitoring result thereof on a display device.

[0019] (11) In the belt conveyor management system according to (10) above, the monitoring device may display the minimum value of the height difference as a monitoring result.

[0020] (12) In the belt conveyor management system according to (10) or (11) above, the monitoring device may issue an alarm when the minimum value of the height difference is less than an alert threshold considering the temporary deflection or vibration amplitude of the belt.

[0021] (13) In the belt conveyor management system according to (12) above, the monitoring device may transmit a cleaning work instruction to an external device when the alarm is issued.

[0022] (14) In the belt conveyor management system according to any one of (1) to (13) above, the monitoring device may output the monitoring result to an external device via a wired or wireless communication interface.

[0023] The (15) belt conveyor management method according to an embodiment of the present disclosure is a method for managing a belt conveyor that conveys a conveyed object by a belt. The belt conveyor management method includes a measurement step of measuring, by a three-dimensional measurement device, the three-dimensional position of the lowermost surface of the belt and the height of a deposit existing below the lowermost surface, respectively, and a monitoring step of monitoring, by a monitoring device, the height of the deposit with respect to the three-dimensional position of the lowermost surface of the belt measured in the measurement step.

Effect of the Invention

[0024] According to the belt conveyor management system and management method according to the present disclosure, the height of the deposit with respect to the three-dimensional position of the lowermost surface of the belt is accurately monitored.

Brief Description of the Drawings

[0025] [Figure 1] It is a schematic diagram showing a configuration example of the belt conveyor management system according to the present disclosure. [Figure 2] It is a cross-sectional view taken along line A-A of FIG. 1. [Figure 3] This flowchart shows an example of a procedure for managing a belt conveyor related to this disclosure. [Figure 4] This is a cross-sectional view showing an example configuration where the conveyor belt is located at the lowest level. [Figure 5] This is a cross-sectional view showing an example configuration in which a 3D measuring device is installed at an upward tilt. [Figure 6] This is a schematic diagram illustrating the maximum tilt angle of a 3D measuring device. [Figure 7A] This is a side view showing an example configuration in which a 3D measuring device is mounted on a stacker. [Figure 7B] This is a front view showing an example configuration in which a 3D measuring device is mounted on a stacker. [Modes for carrying out the invention]

[0026] Hereinafter, embodiments of the belt conveyor 30 management system 1 (see Figure 1, etc.) and management method according to this disclosure will be described with reference to the drawings. Each drawing is schematic and may differ from the actual drawing. The same or corresponding parts in each drawing are denoted by the same reference numerals. In this disclosure, descriptions of the same or corresponding parts will be omitted or simplified as appropriate.

[0027] (Example configuration of Management System 1) As shown in Figures 1 and 2, a management system 1 according to one embodiment of the present disclosure comprises a three-dimensional measuring device 10 and a monitoring device 20.

[0028] The management system 1 manages the belt conveyor 30. The belt conveyor 30 circulates a wide belt arranged in a loop, and transports the objects to be transported 41 loaded on the belt along the direction of the belt's movement. In this disclosure, the objects to be transported 41 are, but are not limited to, raw materials such as iron ore or coal required in the steelmaking process.

[0029] The belt conveyor 30 illustrated in Figures 1 and 2 is arranged so that the belt on which the object to be conveyed 41 is loaded and the belt on which the object to be conveyed 41 is not loaded are aligned vertically, i.e., in the up-and-down direction. The belt located above is also called the upper belt 31. The belt located below is also called the lower belt 32. In Figures 1 and 2, the object to be conveyed 41 is loaded on the upper belt 31. The belt on which the object to be conveyed 41 is loaded is also called the conveying belt. The belt on which the object to be conveyed 41 is not loaded is also called the return belt. In the example in Figure 2, the upper belt 31, i.e. the conveying belt, on which the object to be conveyed 41 is loaded is sagging due to the weight of the object to be conveyed 41. In other words, the upper belt 31 is convex downwards. The lower belt 32, i.e. the return belt, on which the object to be conveyed 41 is not loaded is approximately flat.

[0030] Objects 41 loaded onto the belt of the belt conveyor 30 may fall off the belt during transport. Objects 41 that fall off the belt accumulate on the ground as debris 42. If the debris 42 accumulates to a height, the belt conveyor 30 may come into contact with the debris 42. Contact between the belt conveyor 30 and the debris 42 may cause abnormal conditions such as wear, overheating, belt breakage, or rotational malfunction.

[0031] The belt conveyor 30 and the accumulated material 42 may come into contact at the lowest point of the belt conveyor 30 and the highest point of the accumulated material 42. In the examples of Figures 1 and 2, the lowest point of the belt conveyor 30 is the lower surface 32A of the lower belt 32.

[0032] The management system 1 uses a three-dimensional measuring device 10 to measure the three-dimensional position of the lower surface 32A of the lower belt 32 of the belt conveyor 30 and the three-dimensional position of the highest part of the sediment 42, i.e., the height of the sediment 42. The management system 1 uses a monitoring device 20 to monitor the three-dimensional position of the lower surface 32A of the lower belt 32 and the height of the sediment 42, and manages the belt conveyor 30 to prevent it from coming into contact with the sediment 42. The configuration example of the management system 1 for the belt conveyor 30 according to this disclosure will be described below.

[0033] <3D measuring device 10> The 3D measuring device 10 measures the 3D position of at least one location on the object to be measured. The 3D measuring device 10 may measure 3D point cloud data of the object by measuring the 3D positions of multiple locations on the object. The 3D measuring device 10 may, but is not limited to, be configured to obtain distance or 3D position by irradiating the object with electromagnetic waves and detecting the reflection. The electromagnetic waves may, but are not limited to, light including laser light, millimeter waves, or microwaves. The 3D measuring device 10 may, for example, include an optical ToF (Time of Flight) sensor or a LiDAR (Light Detection And Ranging) sensor. By using an optical sensor, high-density and high-resolution 3D point cloud data can be measured. The 3D measuring device 10 may also include a radar sensor such as a millimeter-wave or microwave FMCW (Frequency Modulated Continuous Wave) type. The radar type can stably acquire reflected signals even in environments where dust, fog, or vapor is present, thus improving the stability of detecting the height of deposited material.

[0034] The 3D measuring device 10 may measure the 3D position of at least one point on the object to be measured by, for example, irradiating the object with light or electromagnetic waves such as millimeter waves or microwaves, and detecting the electromagnetic waves that are reflected back from the object, i.e., reflected waves. As shown in Figure 2, the 3D measuring device 10 may irradiate multiple points on the conveyor belt 30 or sediment 42, as shown by the dashed lines, within the measurement range 12 that spreads out in a fan shape in a cross-sectional view. By detecting the electromagnetic waves that are reflected back from the conveyor belt 30 or sediment 42, the 3D measuring device 10 can measure the distance to the nearest object in each direction within the measurement range 12 as seen from the 3D measuring device 10. Based on the measurement results of direction and distance from the 3D measuring device 10, the 3D measuring device 10 can measure 3D point cloud data of the conveyor belt 30 or sediment 42 included in the measurement range 12.

[0035] The 3D measuring device 10 is positioned such that the central axis 12A of the measurement range 12 is aligned horizontally or substantially horizontally, so that the position of the lower surface 32A of the lower belt 32 of the belt conveyor 30 and the height of the accumulated material 42 can be measured from the side of the belt conveyor 30. Furthermore, the 3D measuring device 10 is positioned lower than the lower surface 32A of the lower belt 32, i.e., the lowest surface, so that the entire 3D position of the lower surface 32A of the lower belt 32 can be measured, that is, so that the entire lower surface 32A of the lower belt 32 is included within the measurement range 12. By positioning the 3D measuring device 10 lower than the lower surface 32A of the lower belt 32, i.e., the lowest surface, with the central axis 12A of the measurement range 12 aligned horizontally or substantially horizontally, electromagnetic waves can be irradiated onto the entire lower surface 32A of the lower belt 32, and the entire 3D position of the lower surface 32A of the lower belt 32 can be measured.

[0036] The 3D measuring device 10 can measure the height of the sediment 42 along with the position of the lower surface 32A of the lower belt 32 by positioning the central axis 12A of the measurement range 12 along the horizontal direction. If there is not much sediment 42, the highest part of the sediment 42 may not be included in the measurement range 12. If there is not much sediment 42, there is no risk of the sediment 42 coming into contact with the belt conveyor 30, so the 3D measuring device 10 may not be able to measure the height of the sediment 42. For example, the 3D measuring device 10 may not be able to measure the height of sediment 42 that has not accumulated to a predetermined height. The predetermined height may be set to a height at which it is necessary to monitor whether the sediment 42 is coming into contact with the lower surface 32A of the lower belt 32. The height at which the 3D measuring device 10 is installed may be set so that electromagnetic waves irradiated below the central axis 12A of the measurement range 12 reach the sediment 42 that has accumulated to at least a predetermined height. In other words, the installation height of the 3D measuring device 10 may be set so that when the accumulated material 42 reaches a height where it is likely to come into contact with the lower surface 32A of the lower belt 32 of the belt conveyor 30, the electromagnetic waves irradiated below the central axis of the measurement range 12 reach the accumulated material 42. By installing the measuring device 10 in this manner, the risk of the accumulated material 42 coming into contact with the lower belt 32 can be reliably detected, improving the reliability of contact prediction.

[0037] The 3D measuring device 10 may be connected to the monitoring device 20 via a network such as a LAN (Local Area Network), and configured to output measurement results to the monitoring device 20.

[0038] <Monitoring device 20> The monitoring device 20 monitors whether the accumulated material 42 is likely to come into contact with the belt conveyor 30, based on the measurement results of the three-dimensional position of the lower surface 32A of the lower belt 32 by the three-dimensional measuring device 10 and the measurement results of the height of the accumulated material 42, and manages to prevent the accumulated material 42 from coming into contact with the belt conveyor 30. The monitoring device 20 may be configured as a computer, for example. The monitoring device 20 may include a processor and a memory unit.

[0039] The processor implements the functions of the monitoring device 20. The processor may include a general-purpose processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). The processor may include a dedicated processor specialized for specific processing. The processor is not limited to these and may include any processor. The processor may implement the functions of the monitoring device 20 by reading and executing a program stored in the memory unit.

[0040] The memory unit may store programs executed by the processor. The memory unit may store the measurement results of the three-dimensional position of the lower surface 32A of the lower belt 32 and the measurement results of the height of the deposit 42. The memory unit may include one or more memories. The memories are, for example, semiconductor memories, magnetic memories, or optical memories, but are not limited to these and can be any memory. The memory unit may include an electromagnetic recording medium such as a hard disk drive (HDD).

[0041] The monitoring device 20 may be connected to the 3D measuring device 10 via a network such as a LAN, and configured to acquire measurement results from the 3D measuring device 10.

[0042] The monitoring device 20 may further include an output device for outputting monitoring results. The output device may include a display device. The display device may include various displays, such as a liquid crystal display. The display device may visually display the monitoring results calculated by the monitoring device 20, including information such as the height of the lowest surface of the belt, the height of the accumulated material, or the minimum value or distribution of the height difference between the two. The output device may include an audio output device such as a speaker, and the audio may include, for example, an alarm sound or voice guidance. The output device may include a light-emitting device such as a lamp, which may emit light to indicate the degree of danger by color classification of the light emitted. The output device is not limited to these and may include various devices.

[0043] The monitoring device 20 may output monitoring results to an external device. The monitoring device 20 may further be equipped with a communication interface for communicating with an external device by wire or wireless connection. The communication interface may be configured to communicate with an external device via a network or without a network. By outputting monitoring results to an external device, the monitoring device 20 can be linked with remote monitoring or automatic control, contributing to faster response to abnormalities.

[0044] The monitoring device 20 can communicate with a control device such as a programmable logic controller (PLC), and may send control signals to gradually reduce the transport speed or perform an emergency stop based on the calculated minimum height difference. The monitoring device 20 may also automatically generate cleaning instructions when an alert is issued and transmit these instructions to an external device. The instructions may include the cleaning target section, estimated accumulation height, safety stop procedure, or return conditions.

[0045] (Example of operation of management system 1) In the management system 1 described herein, the 3D measuring device 10 measures the three-dimensional position of the lower surface 32A of the lower belt 32 of the belt conveyor 30. The lower surface 32A of the lower belt 32 is the lowest surface of the belt of the belt conveyor 30. In other words, the 3D measuring device 10 measures the three-dimensional position of the lowest surface of the belt of the belt conveyor 30. The 3D measuring device 10 also measures the height of the sediment 42 located below the lowest surface of the belt of the belt conveyor 30.

[0046] In this example, the 3D measuring device 10 generates point cloud data of the lower surface 32A of the lower belt 32 and point cloud data of the surface of the sediment 42 within the measurement range 12 as 3D measurement data and outputs it to the monitoring device 20.

[0047] In Figure 2, that is, in the cross-sectional view showing the positional relationship between the belt conveyor 30 and the 3D measuring device 10, the area occupied by the lower surface 32A of the lower belt 32 within the measurement range 12 extends by an angle represented by φ1. As a comparative example, when the 3D measuring device 10 is installed directly beside the lower belt 32, the angle representing the area occupied by the lower surface 32A of the lower belt 32 within the measurement range 12 becomes 0 degrees. In other words, by installing the 3D measuring device 10 below the lower surface 32A of the lower belt 32, as in this example, the 3D measuring device 10 can measure the 3D position of the lower surface 32A of the lower belt 32 over a wide range within the measurement range 12. By being able to measure the 3D position of the lower surface 32A of the lower belt 32 over a wide range, the 3D measuring device 10 can increase the number of data points for the 3D position of the lower surface 32A of the lower belt 32. As a result, the measurement accuracy of the 3D position of the lower surface 32A of the lower belt 32, i.e., the bottommost surface of the belt conveyor 30, is improved.

[0048] The monitoring device 20 monitors the height of the deposit 42 relative to the three-dimensional position of the lower surface 32A of the lower belt 32, based on the three-dimensional measurement data acquired from the three-dimensional measuring device 10. Specifically, the monitoring device 20 detects the three-dimensional position or shape of the lower surface 32A of the lower belt 32 from the three-dimensional measurement data. In the belt conveyor 30 illustrated in Figures 1 and 2, the lower belt 32 is substantially planar. Therefore, the three-dimensional measurement data of the lower surface 32A of the lower belt 32 is obtained as planar data. For example, the monitoring device 20 may calculate a histogram of the Y coordinates of each point in the point cloud data measured as three-dimensional measurement data, assuming that the direction in which the lower belt 32 moves is the X axis, the direction from the lower belt 32 toward the upper belt 31 is the Y axis, and the direction perpendicular to the X and Y axes, i.e., the width direction of the lower belt 32, is the Z axis, and calculate the Y coordinate with the highest frequency in the histogram as the Y coordinate of the lower surface 32A of the lower belt 32. The monitoring device 20 may detect point cloud data representing the position or shape of the lower surface 32A of the lower belt 32 based on the calculation result of the Y coordinate of the lower surface 32A of the lower belt 32. By detecting point cloud data representing the position or shape of the lower surface 32A of the lower belt 32 using a histogram of the Y coordinate of each point in the point cloud data, the monitoring device 20 can stably estimate the height of the lowest surface of the lower belt 32 while being less affected by noise.

[0049] The monitoring device 20 removes the point cloud data representing the three-dimensional position of the lower surface 32A of the lower belt 32 from the point cloud data measured as three-dimensional measurement data within the measurement range 12 of the three-dimensional measuring device 10, and extracts the remaining point cloud data as point cloud data representing the three-dimensional position of the surface of the sediment 42. The monitoring device 20 detects the three-dimensional position or shape of the surface of the sediment 42 from the point cloud data representing the three-dimensional position of the surface of the sediment 42. The monitoring device 20 may calculate the height of the sediment 42 based on the three-dimensional position or shape of the surface of the sediment 42.

[0050] Structures other than the lower belt 32 or the accumulated material 42 may exist around the belt conveyor 30. These structures other than the lower belt 32 or the accumulated material 42 become disturbances in the point cloud data. It is preferable for the monitoring device 20 to remove point cloud data that are disturbances caused by structures other than the lower belt 32 or the accumulated material 42 from the 3D measurement data before detecting the 3D position or shape of the lower surface 32A of the lower belt 32 and the surface of the accumulated material 42 from the 3D measurement data. For example, the monitoring device 20 may determine in advance the range in which the lower belt 32 or the accumulated material 42 exists and remove point cloud data outside that range using threshold processing. For example, the monitoring device 20 may determine in advance the position and shape of a specific structure, such as a column or beam, based on design drawings or measured values, and remove point cloud data corresponding to that specific structure, taking into account the positional relationship between the measurement range 12 and the specific structure. The monitoring device 20 performs preprocessing to remove disturbance point clouds caused by known structures based on their location and shape information, thereby reducing false detections in the detection of the lowest surface of the lower belt 32 and the calculation of the deposit height.

[0051] The monitoring device 20 may apply a plane detection method using a three-dimensional Hough transform as a method for detecting the three-dimensional position of the lower surface 32A of the lower belt 32.

[0052] The monitoring device 20 may compare the height of each position on the lower surface 32A of the lower belt 32, which is the lowest surface of the belt conveyor 30, with the corresponding height of the accumulated material 42, based on the detection results of the three-dimensional position or shape of the lower surface 32A of the lower belt 32 and the detection results of the three-dimensional position or shape of the surface of the accumulated material 42.

[0053] For example, the monitoring device 20 may calculate the difference between the height of the lowest position among the positions on the lower surface 32A of the lower belt 32 and the height of the highest part of the sediment 42.

[0054] Furthermore, for example, the monitoring device 20 may associate points on the lower surface 32A of the lower belt 32 and the surface of the sediment 42 in the aforementioned XYZ coordinate system with points whose X and Z coordinates coincide, and calculate the difference in Y coordinates of the associated points as the difference in height. The monitoring device 20 may calculate the difference in height between the lower surface 32A of the lower belt 32 and the surface of the sediment 42 for each point on the XZ plane. In other words, the monitoring device 20 may calculate the difference between the height of the bottom surface of the belt and the height of the sediment 42 for each of the three-dimensional positions of multiple locations on the bottom surface of the belt measured by the three-dimensional measuring device 10.

[0055] The monitoring device 20 may calculate the difference between the height of a point on the lower surface 32A of the lower belt 32 and the height of a point on the surface of the sediment 42 for all combinations where points with the same X and Z coordinates can be matched. If there is no point on the surface of the sediment 42 corresponding to a point on the lower surface 32A of the lower belt 32, or if there is no point on the lower surface 32A of the lower belt 32 corresponding to a point on the surface of the sediment 42, the monitoring device 20 does not need to calculate the height difference for that point.

[0056] The monitoring device 20 may process the point cloud data acquired from the 3D measuring device 10 in the following order: (i) removal of point clouds corresponding to known structures, (ii) detection of the position or shape of the lowest surface of the lower belt 32 by histogram processing of the Y coordinate or 3D Hough transform, etc., and (iii) calculation of the height difference based on the correspondence in the XZ plane.

[0057] The monitoring device 20 may calculate the minimum value among all combinations of height differences between points on the lower surface 32A of the lower belt 32 and points on the surface of the sediment 42, once the height difference has been calculated for all combinations.

[0058] The monitoring device 20 may display the calculated difference between the height of the lowest point on the lower surface 32A of the lower belt 32 and the height of the highest part of the accumulated material 42, or the minimum value of the calculated height difference for all combinations of points on the lower surface 32A of the lower belt 32 and points on the surface of the accumulated material 42. The manager of the belt conveyor 30 may decide whether to clean the accumulated material 42 based on the calculation results displayed on the monitoring device 20.

[0059] The monitoring device 20 may issue an alert indicating that cleaning of the accumulated material 42 is necessary, based on the calculation result of the difference between the height of the lowest point among all positions on the lower surface 32A of the lower belt 32 and the height of the highest part of the accumulated material 42, or the minimum value of the calculation result of the height difference for all combinations of points on the lower surface 32A of the lower belt 32 and points on the surface of the accumulated material 42. When the monitoring device 20 issues an alert indicating that cleaning is necessary, it may also send a cleaning work instruction to an external device. Sending a cleaning work instruction to an external device automates the transmission of information to on-site workers and prevents delays in response. This allows for the rapid commencement of the accumulated material removal work, prevents the progression of abnormalities in the belt conveyor 30, and contributes to maintaining the operating rate.

[0060] The monitoring device 20 may automatically generate a cleaning work order when an alert is issued and notify the site of the generated cleaning work order by highlighting it on a display device for the target section, notifying it via an audio output device, or notifying it via SMS (Short Message Service).

[0061] The monitoring device 20 may, for example, issue an alert to the operator of the conveyor belt 30 if the minimum value of the calculated difference between the height of the lowest point on the lower surface 32A of the lower belt 32 and the height of the highest part of the accumulated material 42, or the calculated difference in height for all combinations of points on the lower surface 32A of the lower belt 32 and points on the surface of the accumulated material 42, falls below an alert threshold. The operator of the conveyor belt 30 may decide whether to clean the accumulated material 42 in response to the issuance of the alert.

[0062] The monitoring device 20 may send a control signal to the control device of the belt conveyor 30 based on the minimum value of the difference between the height of the lowest point on the lower surface 32A of the lower belt 32 and the height of the highest part of the accumulated material 42, or the minimum value of the difference in height for all combinations of points on the lower surface 32A of the lower belt 32 and points on the surface of the accumulated material 42, thereby gradually reducing the conveying speed of the conveyor and potentially performing an emergency stop if it falls below a predetermined threshold. This concretely realizes industrial applications that physically prevent abnormalities such as wear, heat generation, and belt breakage.

[0063] During continuous operation, the 3D measuring device 10 may be configured to acquire point cloud data at a frequency of 10Hz to 30Hz, and the monitoring device 20 may be configured to calculate the height difference and output an alarm or control within 200 msec. This allows for earlier determination of when to stop, and makes it possible to shorten the stopping distance, which increases with the conveying speed of the conveyor.

[0064] The alert threshold may be set appropriately considering the possibility that the accumulated material 42 may come into contact with the belt conveyor 30. The alert threshold may be set, for example, considering the distance that the lower belt 32 of the belt conveyor 30 may temporarily sag and move downward. The alert threshold may also be set considering the amplitude when the lower belt 32 of the belt conveyor 30 vibrates. The alert threshold may be dynamically updated using the amount of temporary belt sag and vibration amplitude as parameters depending on the operating conditions. Specifically, the alert threshold may be adjusted to the safe side by estimating the range of fluctuation in the height of the lowest surface of the belt over a recent period and adding it to the alert threshold. This can suppress the issuance of false alarms when the belt temporarily sags or vibrates.

[0065] <Example of management procedure> The belt conveyor 30 management system 1 may implement a belt conveyor 30 management method that includes the procedure illustrated in Figure 3. The belt conveyor 30 management method may be implemented as a belt conveyor 30 management program to be executed by the 3D measuring device 10 or the monitoring device 20. The belt conveyor 30 management program may be stored on a non-temporary computer-readable medium.

[0066] The 3D measuring device 10 measures the three-dimensional position of the lower surface 32A of the lower belt 32, which is the lowest surface of the belt conveyor 30 (step S1). The 3D measuring device 10 measures the height of the accumulated material 42 (step S2). The 3D measuring device 10 outputs the 3D measurement data as a measurement result to the monitoring device 20. The procedures in steps S1 and S2 are also referred to as the measurement process.

[0067] The monitoring device 20 monitors the height of the deposit 42 relative to the three-dimensional position of the lower surface 32A of the lower belt 32, which is the lowest surface of the belt conveyor 30, based on the measurement results of the three-dimensional measuring device 10 (step S3). The monitoring device 20 may, for example, display the difference between the height of the lower surface 32A of the lower belt 32 and the height of the deposit 42. The monitoring device 20 may issue an alert indicating that cleaning of the deposit 42 is necessary based on the difference between the height of the lower surface 32A of the lower belt 32 and the height of the deposit 42. The procedure in step S3 is also referred to as the monitoring process.

[0068] The management system 1 for the belt conveyor 30 terminates the execution of the flowchart in Figure 3 after the execution of the procedure in step S3.

[0069] <Summary> According to the belt conveyor 30 management system 1 described herein, the height of the accumulated material 42 relative to the three-dimensional position of the lowest surface of the belt conveyor 30 is monitored.

[0070] As a comparative example, a system can be considered in which the belt is detected from an image of the belt taken from directly beside it, and the height of the belt is calculated. In the system of the comparative example, only the portion of the belt corresponding to its thickness is visible in the image taken from directly beside the belt. Since belts are often thin, it is difficult to improve the accuracy of belt detection. If the belt detection accuracy is low, the accuracy of calculating the height of the lowest surface of the belt will be low. If the calculation error of the height of the lowest surface of the belt is large, the accuracy of monitoring whether the sediment 42 is in contact with the belt will be low.

[0071] On the other hand, in the belt conveyor 30 management system 1 according to this disclosure, the 3D measuring device 10 measures the 3D position of the bottom surface of the belt from below, rather than from directly beside the belt. By measuring the 3D position of the bottom surface of the belt in a planar manner from below, the height of the bottom surface of the belt can be calculated with higher accuracy than when the belt is detected linearly from directly beside it. When the calculation error of the height of the bottom surface of the belt is small, the accuracy of monitoring whether the accumulated material 42 is in contact with the belt is increased.

[0072] In the management system 1 described herein, the 3D measuring device 10 measures the bottom surface of the belt in a planar manner, thus reducing the statistical variance in calculating the bottom surface height compared to conventional linear detection using lateral imaging. This reduces false negatives and false positives in contact predictions with sediment 42, improving the reliability of conservation decisions.

[0073] Furthermore, the management system 1 according to this disclosure can directly calculate the height difference between the three-dimensional position of the lowest surface of the lower belt 32 and the height of the accumulated material 42 located below the lowest surface by simultaneously measuring these two. This configuration allows for quantitative evaluation of the risk of contact with the accumulated material 42 and enables monitoring based on the actual lowest surface position, including temporary deflection or vibration of the belt, thereby reducing false alarms or missed contacts. In addition, by calculating the height difference at multiple locations, it is possible to detect uneven distribution or localized elevation of the accumulated material 42, enabling prioritization of cleaning work or partial operation control. Furthermore, by quantifying and displaying the contact prediction, the objectivity of maintenance decisions is improved, and unnecessary cleaning is avoided, contributing to the efficiency of maintenance work. As a result of these effects, it is possible to prevent abnormalities such as belt breakage or roller rotation failure while avoiding excessive stopping of the belt conveyor 30, thus achieving both safety and operational efficiency.

[0074] As described above, the belt conveyor 30 management system 1 according to this disclosure allows for accurate monitoring of the height of the accumulated material 42 relative to the three-dimensional position of the lowest surface of the belt conveyor 30.

[0075] (Other embodiments) The following describes an example of the configuration of a 3D measuring device 10 according to another embodiment.

[0076] <When the object to be transported 41 is loaded onto the lower belt 32> Figure 4 shows an example configuration when the object to be conveyed 41 is loaded onto the lower belt 32 of the belt conveyor 30. In this case, the lower belt 32 corresponds to the conveying belt. The lower belt 32, i.e., the conveying belt, is sagging due to the weight of the object to be conveyed 41. In other words, the lower belt 32 is convex downwards.

[0077] In the example shown in Figure 4, the bottom surface 32A of the lower belt 32, which is the lowest surface of the belt conveyor 30, is convex when viewed from the 3D measuring device 10. Therefore, the 3D measurement data obtained by the 3D measuring device 10 when measuring the 3D position of the lowest surface of the belt conveyor 30 will be point cloud data of a convex surface.

[0078] The monitoring device 20 may prepare a surface approximation model that includes parameters such as a quadratic function in advance, and use a 3D Hough transform to detect the 3D position or shape of the lower surface 32A of the convex lower belt 32 from the point cloud data measured as 3D measurement data. If the lower belt 32 has a downward convex shape, the shape of the bottom surface may be estimated based on a surface model such as a quadratic function. By measuring the bottom surface of the belt in a planar manner, the accuracy of calculating the bottom surface height is improved compared to the method of capturing the belt thickness linearly from the lateral direction, and it is expected that misjudgments in predicting contact with the sediment 42 will be reduced.

[0079] If no structures other than the lower belt 32 or the sediment 42 exist within the measurement range 12 of the 3D measuring device 10, i.e., if the point cloud data does not contain any disturbance factors, the monitoring device 20 may extract point cloud data representing the 3D position or shape of the lower surface 32A of the lower belt 32 by simple thresholding.

[0080] The monitoring device 20 may, similar to the operation example described above, extract point cloud data representing the three-dimensional position of the surface of the sediment 42 to calculate the height of the sediment 42, and then calculate the difference between the height of the bottom surface of the belt conveyor 30 and the height of the sediment 42.

[0081] <When the 3D measuring device 10 is installed tilted upwards with respect to the horizontal> Figure 5 shows an example configuration comprising a three-dimensional measuring device 13 installed at an upward tilt relative to the horizontal direction. The three-dimensional measuring device 13 is installed such that the central axis 14A of the measurement range 14 is tilted with respect to the ground at an angle represented by θ. In Figure 5, the ground extends in the horizontal direction.

[0082] In Figure 5, that is, in the cross-sectional view showing the positional relationship between the belt conveyor 30 and the 3D measuring device 10, the area occupied by the lower surface 32A of the lower belt 32 within the measurement range 14 is extended by an angle represented by φ2. The angle φ2 in the arrangement of the 3D measuring device 13 in Figure 5 is larger than the angle φ1 in the arrangement of the 3D measuring device 10 in Figure 2. In other words, the 3D measuring device 13, which is installed at an upward tilt, can measure the 3D position of the lower surface 32A of the lower belt 32 over a wider range within the measurement range 14 than the 3D measuring device 10, which is installed horizontally. By being able to measure the 3D position of the lower surface 32A of the lower belt 32 over a wider range, the 3D measuring device 13 can increase the number of data points for the 3D position of the lower surface 32A of the lower belt 32. As a result, the measurement accuracy of the 3D position of the lower surface 32A of the lower belt 32, i.e., the bottommost surface of the belt conveyor 30, is improved.

[0083] Electromagnetic waves emitted from the 3D measuring device 13, which is installed at an upward tilt relative to the horizontal, may not reach a portion of the area below the lower surface 32A of the lower belt 32 if the sediment 42 is deposited higher than the position of the 3D measuring device 13, as the sediment 42 blocks the electromagnetic waves. The area where the electromagnetic waves do not reach is also called the dead zone of the 3D measuring device 13. The dead zone of the 3D measuring device 13 is the area in which the 3D measuring device 13 cannot measure the 3D position.

[0084] If a portion of the widthwise lower surface 32A of the lower belt 32 is included in the dead zone of the 3D measuring device 13, the number of point cloud data obtained as 3D measurement data of the lower surface 32A of the lower belt 32 will decrease. This decrease in the number of point cloud data of the lower surface 32A of the lower belt 32 will reduce the detection accuracy of the 3D position or shape of the lower surface 32A of the lower belt 32. As a result, the accuracy of calculating the difference between the height of the lower surface 32A of the lower belt 32 and the height of the sediment 42 will decrease.

[0085] Therefore, an upper limit may be set for the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal direction, so that the entire widthwise surface 32A of the lower belt 32 is not included in the dead zone of the 3D measuring device 13.

[0086] Specifically, for example, as shown in Figure 6, assuming that the peak of the sediment 42 is located above the central axis 14A of the measurement range 14 of the 3D measuring device 13, which is installed tilted upward with respect to the horizontal, and at the end of the lower belt 32 on the side closer to the 3D measuring device 13 in the width direction, the maximum value θmax of the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal can be estimated. The maximum value of the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal is also called the maximum angle.

[0087] In Figure 6, the width of the lower belt 32 is represented by W. Furthermore, L represents the difference between the height at which the accumulated material 42 is most likely to accumulate without being removed by cleaning under the management system 1, and the height of the lower surface 32A of the lower belt 32. The height at which the accumulated material 42 is most likely to accumulate without being removed by cleaning may be the height at which the accumulation of material 42 is permitted until the manager of the belt conveyor 30 decides to perform cleaning of the accumulated material 42. In other words, the value of L may be a value that the manager of the belt conveyor 30 can accept as the difference between the height of the lower surface 32A of the lower belt 32 and the height of the accumulated material 42. The value of L may be set to be the same as the alert threshold, or it may be set according to the judgment of the manager of the belt conveyor 30.

[0088] The θmax shown in Figure 6 is calculated by the following equation (1). The function arctan(·) in equation (1) is the arctangent. θmax = arctan(L / W) (1) In other words, θmax is the angle calculated as the arctangent of the height obtained by dividing the allowable difference between the height of the lowest surface of the belt of the belt conveyor 30, i.e., the lower surface 32A of the lower belt 32, and the height of the accumulated material 42, by the width of the lower belt 32.

[0089] For example, if the width (W) of the lower belt 32 is 1000 mm and the value of L is set to 100 mm, the maximum angle θmax for tilting the 3D measuring device 13 upwards with respect to the horizontal is calculated to be 5.7 degrees.

[0090] Generally, considering that the belt width W is 300 mm or more, when W = 300 mm and L is set to 100 mm, θmax is calculated as 18.4 degrees. Thus, when considering the range of typical belt widths, θmax may be set within a range of 18.4 degrees or less.

[0091] By setting the tilt angle of the 3D measuring device 13 to less than or equal to θmax calculated by equation (1), the occurrence of dead zones is suppressed, and the point cloud density for the lowest surface can be ensured. Consequently, the acquisition range of point cloud data for the lowest surface of the lower belt 32 is widened, so the detection of the position or shape of the lowest surface becomes more stable, and the estimation error of the difference between the height of the lowest surface of the belt and the height of the sediment can be reduced.

[0092] Assuming that the apex of the sediment 42 is located above the central axis 14A of the measurement range 14 of the 3D measuring device 13, which is installed tilted upward with respect to the horizontal, and at the end of the lower belt 32 on the side closer to the 3D measuring device 13 in the width direction, if the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal is less than or equal to θmax, then the entire lower surface 32A of the lower belt 32 is included in the measurement range 14.

[0093] On the other hand, if the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal is greater than θmax, a portion of the lower surface 32A of the lower belt 32, that is, the portion of the lower belt 32 that is far from the 3D measuring device 13 in the width direction, is not included in the measurement range 14.

[0094] Therefore, when the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal is less than or equal to θmax, the number of point cloud data points on the lower surface 32A of the lower belt 32 is greater than when the angle at which the 3D measuring device 13 is tilted upward with respect to the horizontal is greater than θmax. The increased number of point cloud data points on the lower surface 32A of the lower belt 32 improves the detection accuracy of the 3D position or shape of the lower surface 32A of the lower belt 32. As a result, the accuracy of calculating the difference between the height of the lower surface 32A of the lower belt 32 and the height of the sediment 42 is improved.

[0095] The 3D measuring device 13 may be housed in a dustproof and waterproof enclosure suitable for environments with dust or moisture, and may be configured to maintain the tolerance of the inclination angle θ using an installation jig. During maintenance, it is easy to verify that the inclination angle is less than or equal to θmax using the jig.

[0096] (Embodiment of a mobile-mounted 3D measuring device 10 or 13) This embodiment relates to a configuration in which a three-dimensional measuring device 10 or 13 is mounted on a mobile machine 50 that travels along a belt conveyor 30 in a raw material yard to load or unload raw materials, and while continuously acquiring three-dimensional measurement data such as point clouds as the mobile machine 50 travels, it monitors the lower surface 32A of the lower belt 32 of the belt conveyor 30 and the height of the deposits 42 that may be formed below the lower surface 32A. The mobile machine 50 may, but is not limited to, a stacker or a reclaimer.

[0097] Figures 7A and 7B show an example configuration in which a stacker is used as the mobile machine 50, and a three-dimensional measuring device 10 or 13 is mounted on the mobile machine 50. As shown in the side view of Figure 7A, the mobile machine 50 is supported by a plurality of legs 52 and running wheels 53 provided thereon, and is configured to travel along a pair of parallel rails 51, dropping the raw materials conveyed by the belt conveyor 30 to a predetermined location off the rails 51 to form a raw material pile 58. As shown in the front view of Figure 7B, the mobile machine 50 has a structure that straddles the belt conveyor 30, and incorporates a portion of the belt, including the upper belt 31 and the lower belt 32, into the machine body. Furthermore, the mobile machine 50 is equipped with an on-board belt conveyor 54 that takes over the conveyed objects 41. The conveyed objects 41 fall from the front of the on-board belt conveyor 54 to form a raw material pile 58.

[0098] As shown in Figure 7B, the 3D measuring device 10 or 13 is installed near the legs 52 of the mobile machine 50 in a position such that its measurement range encompasses the lower surface 32A of the lower belt 32 and the area below the lower belt 32, which is the space where the sediment 42 is assumed to exist. While the mobile machine 50 is traveling, the 3D measuring device 10 or 13 continuously acquires point clouds at a predetermined sampling period. The monitoring device 20 identifies the positional relationship between the continuous point clouds based on the point clouds acquired at each acquisition time and travel distance information, which includes information on position, orientation, or amount of movement acquired by at least one of an encoder, GNSS (Global Navigation Satellite System), or IMU (Inertial Measurement Unit). In this way, the 3D position of the lower surface 32A of the lower belt 32, or the 3D position including the shape of the lower surface 32A, and the height distribution of the sediment 42 are restored and updated over a wide area along the travel path.

[0099] The 3D measuring device 10 or 13 detects objects 55 falling from the lower belt 32 of the belt conveyor 30 and the deposits 42 formed below the lower surface 32A of the lower belt 32 due to the objects 55. The monitoring device 20 calculates (i) the 3D position including the lowest edge positions at multiple locations on the lower surface 32A, and (ii) the maximum total height of the corresponding deposits 42, and calculates the minimum value of the height difference between the two as a monitoring index. The monitoring device 20 issues a warning if the minimum value is greater than or equal to the alert threshold, and issues a control signal for a gradual reduction in the conveying speed or an emergency stop if the minimum value is less than the alert threshold.

[0100] When a three-dimensional measuring device 10 with a nearly horizontal field of view is used, it is easy to increase the point cloud density of the lower surface 32A of the lower belt 32 over the entire width of the belt conveyor 30. On the other hand, when a three-dimensional measuring device 13 with an upwardly inclined field of view is used, by inclining it upward at an angle less than or equal to the maximum inclination angle θmax, it is possible to acquire a point cloud over the entire lower surface 32A of the lower belt 32 while suppressing the occurrence of dead zones even when the sediment 42 is piled up. The upper limit of the inclination angle θmax may be determined by a relational expression including the arctangent based on the belt width W and the allowable height L, which is expressed as equation (1).

[0101] According to this embodiment, data over long distances can be acquired in a short time by the mobile unit 50's patrol travel. Therefore, compared to the case where the 3D measuring device 10 or 13 is fixedly installed, it becomes possible to grasp the accumulation status of sediment 42 around the lower belt 32 at a high frequency and crosswise over a wide area while reducing the number of 3D measuring devices 10 or 13 installed. The 3D measuring device 10 or 13 in a mobile installation configuration mounted on the mobile unit 50 may be used in combination with a 3D measuring device 10 or 13 in a fixed installation configuration fixed to the ground, foundation, frame or support of the raw material yard or the frame of the belt conveyor. By operating high-precision and continuous monitoring at fixed points and monitoring by patrolling a wide area using the mobile unit 50 in a complementary manner, the possibility of early detection of localized elevations or uneven distribution of sediment 42 is increased, and the certainty of dealing with the sediment 42 is further enhanced.

[0102] While embodiments of this disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art can make various modifications or alterations based on this disclosure. Therefore, it should be noted that these modifications or alterations are included within the scope of this disclosure. For example, the functions included in each component or step can be rearranged in a logically consistent manner, and multiple components or steps can be combined into one or divided. Embodiments relating to this disclosure can also be realized as programs executed by a processor in the device or as storage media recording such programs. These should also be understood to be included within the scope of this disclosure. [Explanation of symbols]

[0103] 1 Management System 10. Three-dimensional measuring device (12: measurement range, 12A: central axis of the measurement range) 13. Three-dimensional measuring device (14: measurement range, 14A: central axis of the measurement range) 20 Monitoring equipment 30 Belt conveyor (31: upper belt, 32: lower belt, 32A: bottom surface) 41. Objects to be transported 42 Sediments 50 Mobile devices 51 rails 52 Legs 53 Running wheels 54. Onboard conveyor belt 55 Falling objects 58 Raw Material Mountain

Claims

1. A management system for a belt conveyor that transports objects by belt, A three-dimensional measuring device for measuring the three-dimensional position of the lowest surface of the belt and the height of the sediment located below the lowest surface, A monitoring device that monitors the height of the deposit relative to the three-dimensional position of the bottom surface of the belt, based on the three-dimensional point cloud data corresponding to the bottom surface of the belt and the three-dimensional point cloud data corresponding to the surface of the deposit measured by the three-dimensional measuring device, Equipped with, The monitoring device is a belt conveyor management system that estimates the height of the bottom surface of the belt by using a histogram of the Y coordinate of the three-dimensional point cloud data corresponding to the bottom surface of the belt, in a coordinate system in which the direction of movement of the belt is the X axis, the vertical direction of the belt is the Y axis, and the width direction of the belt is the Z axis.

2. The three-dimensional measuring device is configured to obtain distance or three-dimensional position by irradiating an object to be measured with electromagnetic waves and detecting the reflection thereof, wherein the electromagnetic waves are light, millimeter waves, or microwaves, as described in claim 1 for the belt conveyor management system.

3. The belt conveyor management system according to claim 2, wherein the installation height of the three-dimensional measuring device is set such that when the sediment reaches a height at which it is likely to come into contact with the lowest surface of the belt, the electromagnetic waves irradiated below the central axis of the measurement range reach the sediment.

4. The belt conveyor management system according to any one of claims 1 to 3, wherein the three-dimensional measuring device is positioned lower than the lowest surface of the belt and the central axis of its measuring range is positioned along a substantially horizontal direction.

5. The three-dimensional measuring device is installed such that the central axis of the measuring range of the three-dimensional measuring device is tilted upward with respect to the horizontal at an angle less than or equal to the maximum angle. The maximum angle is calculated as the arctangent of the value obtained by dividing the allowable height difference between the height of the lowest surface of the belt and the height of the deposit by the width of the belt. A belt conveyor management system according to any one of claims 1 to 3.

6. The belt conveyor management system according to any one of claims 1 to 3, wherein the three-dimensional measuring device is mounted on a mobile machine capable of traveling along a belt conveyor in a raw material yard, or is fixedly installed to the ground, foundation, frame or support or the structure of the belt conveyor in the raw material yard.

7. The belt conveyor management system according to any one of claims 1 to 3, wherein the monitoring device calculates the difference between the height of the bottom surface of the belt and the height of the deposit, corresponding to each of the three-dimensional positions of the multiple locations on the bottom surface of the belt measured by the three-dimensional measuring device.

8. The belt conveyor management system according to any one of claims 1 to 3, wherein the monitoring device performs preprocessing to remove three-dimensional point cloud data caused by a known structure based on the location and shape information of the structure.

9. The belt conveyor management system according to claim 1, wherein the monitoring device calculates the height difference, which is the difference in the Y coordinate between the lowest surface and the surface of the deposit, for each point on the XZ plane, and displays the height difference or the monitoring result on a display device.

10. The belt conveyor management system according to claim 9, wherein the monitoring device displays the minimum value of the height difference as a monitoring result.

11. The belt conveyor management system according to claim 9 or 10, wherein the monitoring device issues an alarm when the minimum value of the height difference falls below an alert threshold that takes into account the temporary deflection or vibration amplitude of the belt.

12. The management system according to claim 11, wherein the monitoring device transmits cleaning instructions to an external device when the alarm is issued.

13. The belt conveyor management system according to any one of claims 1 to 3, wherein the monitoring device outputs the monitoring results to an external device via a wired or wireless communication interface.

14. A method for managing a belt conveyor that transports objects by belt, A measurement step in which a three-dimensional measuring device is used to measure the three-dimensional position of the lowest surface of the belt and the height of the sediment located below the lowest surface, A monitoring step in which a monitoring device monitors the height of the deposit relative to the three-dimensional position of the bottom surface of the belt, based on the three-dimensional point cloud data corresponding to the bottom surface of the belt and the three-dimensional point cloud data corresponding to the surface of the deposit measured in the measurement step, and Includes, The monitoring step is a method for managing a belt conveyor, in which the height of the lowest surface of the belt is estimated by a histogram of the Y coordinate of the three-dimensional point cloud data corresponding to the lowest surface of the belt, in a coordinate system in which the direction of movement of the belt is the X axis, the vertical direction of the belt is the Y axis, and the width direction of the belt is the Z axis.

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