Moisture content specification system and method for specifying moisture content

Abstract

To provide a moisture content specification system and a method for specifying a moisture content which can specify a precise and continuous moisture content even in a case where an RI moisture meter is applied when a material is conveyed by a belt conveyor.SOLUTION: The present invention relates to a moisture content specification system 10 for specifying the moisture content of a material M conveyed by a belt conveyor 20. The system includes: a belt conveyor 20; an RI moisture meter 40 arranged on the back side of the belt 22; a laser scanner 30 arranged on the front side of the belt 22, the scanner measuring the top end line of the belt 22 and the top end line of the material M; and an operation device 70. The operation device 70 acquires the measured value of the moisture content obtained by the RI moisture meter 40, acquires a material top end line measured value and a belt top end line measured value, executes a first correction to correct the moisture content measured value on the basis of the height distribution calculation value of a two-dimensional cross-sectional shape calculated on the basis of the difference between the material top end line measured value and the belt top end line measured value, and specifies the moisture content of the material M.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a moisture amount determining system and a moisture amount determining method. [Background technology]

[0002] The moisture content of soil materials (water content and surface water content) is an important indicator as a construction and quality control standard in civil engineering. Moisture meters using RI (Radio Isotope) are widely used as a simple means of measuring moisture content at construction sites. Among these, scattering-type RI moisture meters have few installation restrictions and enable continuous, non-destructive measurements, making them useful in a variety of technologies aimed at improving construction and quality control and reducing labor, including surface compaction management of ground.

[0003] Incidentally, one of the characteristics of RI moisture meters is that the measured value is affected by the volume and density of the sample inside or near the boundary of the measurement range, and by the variation in the distance between the RI moisture meter and the material (the amount and distribution of water molecules within the detection range). For this reason, the range of application of the RI moisture meter has traditionally been limited to areas where these variations are minimal. For example, in trapezoidal CSG (Cemented Sand and Gravel, a material obtained by mixing locally generated gravel, cement, and water) dam construction, installation is limited to the bottom of a large belt feeder where a sufficient conveying thickness can be ensured, or on the side of a weighing hopper where the material remains stationary for a certain period of time, and its application to belt conveyors, which generally have a small conveying thickness and many variable factors, is not considered because it is difficult to ensure measurement accuracy. The quality of trapezoidal CSG dams is determined by the grain size and moisture content of the CSG material. Conventionally, the moisture content of CSG material is controlled by manual testing, but this is labor-intensive and has issues such as intermittent sampling due to the nature of the testing.

[0004] For these reasons, there is a need for a moisture content determination system that can determine the moisture content continuously and with high accuracy, even when an RI moisture meter is used in an environment where the measurement conditions and properties of the object being measured fluctuate, such as when materials are transported by a conveyor belt.

[0005] Here, Patent Document 1 proposes a soil quality adjustment device. This quality adjustment device includes a moisture content measuring device and a belt scale that measure the moisture content of the soil carried on two belt conveyors, and a control device that controls the two belt conveyors. The control device measures the moisture content and wet weight of the first soil carried in the first group and the moisture content and wet weight of the second soil carried in the second group, respectively, using the moisture content measuring device and belt scale equipped on each belt conveyor. Then, the control device controls the conveyance of the first soil and the second soil on each belt scale so that the moisture content of the third soil, which is a mixture of the first soil and the second soil, is a target value. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2019-105041 A Summary of the Invention [Problem to be solved by the invention]

[0007] The soil quality adjustment device described in Patent Document 1 can adjust the moisture content of generated soil, but it does not disclose a technology that can resolve the above-mentioned problem, that is, a technology for continuously determining the moisture content with high accuracy even when an RI moisture meter is applied when transporting materials by belt conveyor.

[0008] The present invention aims to provide a moisture content determination system and a moisture content determination method that can determine the moisture content continuously with high accuracy, even when an RI moisture meter is applied to an environment in which the measurement conditions and the properties of the object to be measured fluctuate when materials are transported by a belt conveyor. [Means for solving the problem]

[0009] In order to achieve the above object, one aspect of the moisture content specifying system according to the present invention is to A moisture content determining system for determining a moisture content of a material conveyed by a belt conveyor, comprising: The belt conveyor; An RI moisture meter disposed on the back side of the belt forming the belt conveyor and measuring the moisture content of the material; A laser scanner is disposed on the surface side of the belt and measures both the top line of the belt and the top line of the material at a measurement cross-sectional position perpendicular to the width direction of the belt; A computing device, The computing device includes: Obtain a moisture content measurement value using the RI moisture meter; A material top line measurement value relating to the top line of the material and a belt top line measurement value relating to the top line of the belt are obtained; A height distribution calculation value relating to the height distribution of the two-dimensional cross-sectional shape of the material at the measurement cross-sectional position is calculated based on the difference between the material top line measurement value and the belt top line measurement value; The moisture content of the material is identified by performing a first correction, which corrects the moisture content measurement value based on the height distribution calculation value.

[0010] According to this embodiment, the moisture content of the material is measured using an RI moisture meter, a laser scanner arranged on the surface side of the belt of the belt conveyor measures the belt top line and the material top line at the measurement cross-sectional position perpendicular to the width direction of the belt, and a calculation device corrects the moisture content measurement value using a height distribution calculation value related to the height distribution of the two-dimensional cross-sectional shape calculated based on the difference between the material top line measurement value and the belt top line measurement value.By performing a first correction, it is possible to perform continuous moisture content determination with high accuracy even when the RI moisture meter is applied in an environment where the properties (shape) of the material changes as it is continuously transported on a belt conveyor. In other words, the moisture content measurement value of the material within the measurement area measured by the RI moisture meter fluctuates due to fluctuations in the top line of the material transported on the conveyor belt, and a first correction is performed on the actual moisture content measurement value, which leads to a highly accurate determination of the moisture content.

[0011] Here, it is preferable to use a scattering-type RI moisture meter as the RI moisture meter, which has few installation restrictions and allows continuous, non-destructive measurement. Laser scanners include 2D range sensors and 3D range sensors. For conveyor belts whose width exceeds the inspection range of the applicable RI moisture meter (e.g., a diameter of about 30 cm), multiple RI moisture meters may be installed at intervals in the width direction.In this configuration, the first correction can be performed on the average moisture measurement value obtained by averaging the moisture measurement values ​​from each RI moisture meter. In addition, materials for which moisture content is to be determined include aggregates such as CSG materials (locally generated sand and gravel) used in CSG dams and coarse aggregates used in concrete production, as well as various other soil materials such as embankments, backfill soil, and cement-based improved soil.

[0012] In another aspect of the moisture content determining system according to the present invention, The computing device includes: A height distribution reference value relating to the height distribution of the two-dimensional cross-sectional shape is stored; The first correction is performed to correct the moisture content of the material in accordance with a ratio of the height distribution calculation value to the height distribution reference value.

[0013] According to this aspect, the first correction corrects the moisture content of the material in accordance with the ratio of the height distribution calculated value for the height distribution of the two-dimensional cross-sectional shape to the height distribution reference value for the height distribution of the two-dimensional cross-sectional shape of the material, thereby enabling the moisture content measurement value to be corrected with high accuracy, and continuous moisture content determination can be performed with even greater accuracy.

[0014] In another aspect of the moisture content determining system according to the present invention, The computing device includes: storing a contribution rate of each width direction divided block to an entire moisture content of the two-dimensional cross-sectional shape for each width direction divided block obtained by dividing the two-dimensional cross-sectional shape into a plurality of width direction divided blocks in the width direction of the belt; The product of the approximation expression of the height distribution in each width-direction divided block and the contribution rate is calculated, and the sum of the products of all the width-direction divided blocks is calculated to obtain a first correction coefficient; The first correction includes calculating a product of the moisture amount measurement value and the first correction coefficient.

[0015] According to this embodiment, the two-dimensional cross-sectional shape is divided into multiple widthwise divided blocks in the width direction of the belt, the contribution rate of each widthwise divided block to the overall moisture content of the two-dimensional cross-sectional shape is multiplied by an approximation equation for the height distribution in each widthwise divided block, and the sum of the products of all the widthwise divided blocks is calculated to obtain a first correction coefficient.In the first correction, the moisture content measurement value is multiplied by the first correction coefficient, thereby making it possible to correct the moisture content measurement value easily and with high accuracy, and to perform continuous moisture content determination with even higher accuracy.

[0016] The distribution of the contribution rate (frequency of neutron counting) of the RI measurement value in the cross section (two-dimensional cross-sectional shape) in the width direction of the belt can be obtained as a two-dimensional probability distribution, for example, by the Monte Carlo method. When measuring materials on a belt conveyor, the contribution rate tends to be largest immediately above the center of the RI moisture meter and to become smaller toward the periphery. In this way, the distribution of the contribution rate is originally expressed as a two-dimensional function, and for example, a density function of a two-dimensional normal distribution can be cited as an example. However, in practice, the present embodiment is to perform the first correction under a simpler contribution rate setting, in which the cross section is divided into multiple blocks and the average contribution rate within each block is set.

[0017] In another aspect of the moisture content determining system according to the present invention, The contribution rate of the width direction divided block is determined as the sum of the contribution rates of a plurality of height direction divided blocks obtained by further dividing the width direction divided block in the height direction.

[0018] According to the present embodiment, by calculating the contribution rate of a width-direction divided block as the sum of the contribution rates of each of a plurality of height-direction divided blocks obtained by further dividing the width-direction divided block in the height direction, the contribution rate of the width-direction divided block can be calculated with higher accuracy, thereby making it possible to set the first correction coefficient with even higher accuracy.

[0019] Another aspect of the moisture content specifying system according to the present invention is to a pair of support rollers disposed on the back side of the belt, supporting the belt while rotatably contacting the back side of the belt, and sandwiching the RI moisture meter therebetween; The measurement cross-section position is set directly above the RI moisture meter.

[0020] According to the present embodiment, by further providing a pair of support rollers that are arranged on the back side of the belt and support the belt while rotatably contacting the back side of the belt and sandwiching the RI moisture meter, it is possible to suppress fluctuations of the belt at the measurement cross-sectional position, and it is possible to determine the moisture content with even greater accuracy.

[0021] Another aspect of the moisture content specifying system according to the present invention is to Further, a laser distance meter is provided on the back side of the belt to measure a distance to the back side of the belt, The computing device includes: storing a distance reference value relating to the distance to the back surface of the belt; Obtaining a distance measurement value by the laser range finder; The moisture content of the material is determined by further performing a second correction, which corrects the moisture content of the material according to the ratio of the distance measurement value to the distance reference value or the difference between the distance reference value and the distance measurement value.

[0022] According to this embodiment, the distance to the back surface of the belt is measured using a laser range finder arranged on the back surface of the belt, and a second correction is further performed in addition to the first correction to correct the moisture content of the material based on the ratio of the distance measurement value to a distance reference value relating to the distance from the laser range finder to the back surface of the belt, or the difference between the distance reference value and the distance measurement value, thereby making it possible to determine the moisture content with even greater accuracy.

[0023] That is, the moisture content measurement value of the material in the measurement area measured by the RI moisture meter fluctuates due to fluctuations in the belt top line caused by weight fluctuations of the material transported on the belt conveyor, and by performing a second correction on the actual moisture content measurement value, this leads to highly accurate determination of the moisture content. The first correction corrects the moisture content measurement value for the fluctuations in the material top line, and the second correction corrects the moisture content measurement value for the fluctuations in the belt top line, thereby improving the accuracy of determining the moisture content.

[0024] In another aspect of the moisture content determining system according to the present invention, The two laser distance meters are disposed at positions corresponding to two gaps between the pair of support rollers and the RI moisture meter located therebetween.

[0025] According to this aspect, the pair of support rollers suppresses fluctuation of the belt at the measurement cross-sectional position, and the distance to the back surface of the belt can be stably measured.

[0026] Another aspect of the moisture content specifying system according to the present invention is to The support roller is provided with a load cell, or a belt scale is provided on the back side of the belt, and the weight of the material is measured by the load cell or the belt scale. The computing device includes: A weight measurement value obtained by the load cell or the belt scale is obtained, storing a weight reference value of the material to be conveyed; The moisture content of the material is determined by further performing a third correction, which corrects the moisture content of the material according to the ratio of the weight measurement value to the weight reference value.

[0027] According to this embodiment, by performing a third correction, which corrects the moisture content of the material depending on the ratio of the weight measurement value to the weight measurement value obtained by a load cell or belt scale, in addition to the first correction, or in addition to the first and second corrections, it is possible to determine the moisture content with even greater accuracy.

[0028] In other words, the moisture content measurement value of the material in the measurement area by the RI moisture meter fluctuates due to fluctuations in the properties (weight) of the material transported on the belt conveyor, and by performing the third correction on the actual moisture content measurement value, this leads to highly accurate moisture content determination. The first correction corrects the moisture content measurement value for fluctuations in the material top line, the second correction corrects the moisture content measurement value for fluctuations in the belt top line, and the third correction corrects the moisture content measurement value for fluctuations in the weight of the material, thereby improving the accuracy of moisture content determination.

[0029] In addition, one aspect of the moisture content determining method according to the present invention is to A moisture content determination method for determining a moisture content of a material conveyed by a belt conveyor, comprising the steps of: Measure the moisture content of the material conveyed by the belt conveyor to obtain a moisture content measurement value; The top line of the belt and the top line of the material are measured at a measurement cross-sectional position perpendicular to the width direction of the belt forming the belt conveyor, and the measured values ​​are set as a belt top line measurement value and a material top line measurement value. The moisture content of the material is determined by a first correction that calculates a height distribution calculation value relating to the height distribution of the two-dimensional cross-sectional shape of the material at the measured cross-sectional position based on the difference between the material top line measurement value and the belt top line measurement value, and corrects the moisture content measurement value based on the height distribution measurement value.

[0030] According to this embodiment, the moisture content of the material is measured using an RI moisture meter, a laser scanner arranged on the surface side of the belt of the belt conveyor measures the belt top line and the material top line at the measurement cross-sectional position perpendicular to the width direction of the belt, and a calculation device corrects the moisture content measurement value using a height distribution calculation value related to the height distribution of the two-dimensional cross-sectional shape calculated based on the difference between the material top line measurement value and the belt top line measurement value.By performing a first correction, it is possible to continuously determine the moisture content with high accuracy even when the RI moisture meter is applied in an environment where the properties (shape) of the material changes as it is continuously transported on a belt conveyor.

[0031] In another aspect of the moisture content determining method according to the present invention, The first correction is characterized in that the moisture content of the material is corrected in accordance with a ratio of the height distribution calculated value to a height distribution reference value related to the height distribution of the two-dimensional cross-sectional shape.

[0032] According to this embodiment, the first correction corrects the moisture content of the material in accordance with the ratio of the height distribution calculated value for the height distribution of the two-dimensional cross-sectional shape to the height distribution reference value for the height distribution of the two-dimensional cross-sectional shape of the material, thereby making it possible to correct the moisture content measurement value with high accuracy, and to determine the moisture content continuously with even greater accuracy.

[0033] In another aspect of the moisture content determining method according to the present invention, For each of the widthwise divided blocks into which the two-dimensional cross-sectional shape is divided in the width direction of the belt, a contribution rate of each widthwise divided block to the entire moisture content of the two-dimensional cross-sectional shape is calculated; The product of the approximation expression of the height distribution of each width-direction divided block and the contribution rate is calculated, and the sum of the products of all the width-direction divided blocks is calculated to obtain a first correction coefficient; The first correction is characterized by calculating a product of the moisture amount measurement value and the first correction coefficient.

[0034] According to this embodiment, the two-dimensional cross-sectional shape is divided into multiple width-directional divided blocks in the width direction of the belt, the contribution rate of each width-directional divided block to the overall moisture content of the two-dimensional cross-sectional shape is multiplied by an approximation equation for the height distribution in each width-directional divided block, and the sum of the products of all the width-directional divided blocks is calculated to obtain a first correction coefficient.In the first correction, the moisture content measurement value is multiplied by the first correction coefficient, thereby making it possible to correct the moisture content measurement value easily and with high accuracy, and to determine the moisture content continuously with even higher accuracy. Effect of the Invention

[0035] According to the moisture content determining system and moisture content determining method of the present invention, the moisture content can be determined continuously with high accuracy even when an RI moisture meter is used in an environment where the measurement conditions and properties of the object to be measured fluctuate when materials are transported by a conveyor belt. [Brief description of the drawings]

[0036] [Figure 1] 1 is a plan view of an example of a belt conveyor material transport system in which an example of a moisture content determination system according to an embodiment is applied; FIG. [Diagram 2] FIG. 1 is a perspective side view of an example belt conveyor material handling system showing a belt conveyor. [Diagram 3] FIG. 1 is a top perspective view of an example of a belt conveyor material handling system, taken at a mid-way point along the belt conveyor. [Figure 4] This is a diagram that illustrates the change in the top line of the material due to changes in the volume of soil being transported and the change in the belt shape of the belt conveyor. [Diagram 5] FIG. 13 is a diagram illustrating the distribution of contribution rates of measurement values ​​obtained by an RI moisture meter within a cross section of a belt in the width direction. [Figure 6] FIG. 2 is a diagram showing an example of a hardware configuration of a computing device forming an example of a moisture content specifying system according to an embodiment. [Figure 7] FIG. 2 is a diagram showing an example of a functional configuration of a calculation device that constitutes an example of a moisture content specifying system according to an embodiment, together with peripheral devices. [Figure 8] 11 is a flowchart showing a case where three types of correction methods applied in the moisture content specifying method according to the embodiment are performed consecutively. [Figure 9] FIG. 13 is a diagram showing an example of a calibration formula based on the water content of a collected sample. [Figure 10] FIG. 13 is a front view of each device at the measurement cross-section position. [Figure 11] 11 is a view taken along the line XI-XI in FIG. 10, showing the devices at the measurement cross section position as viewed from the side. [Figure 12] FIG. 1 is a first explanatory diagram for explaining the first correction. [Figure 13] FIG. 2 is a second explanatory diagram for explaining the first correction. [Figure 14] FIG. 3 is a third explanatory diagram for explaining the first correction. [Figure 15A] FIG. 4 is a fourth explanatory diagram for explaining the first correction. [Figure 15B] FIG. 5 is a fifth explanatory diagram for explaining the first correction. [Figure 15C] FIG. 6 is an explanatory diagram for explaining the first correction. [Figure 16] FIG. 7 is an explanatory diagram for explaining the first correction. [Figure 17] FIG. 11 is an explanatory diagram for explaining a second correction. [Figure 18] FIG. 11 is an explanatory diagram for explaining a third correction. [Figure 19] FIG. 1 is a diagram showing specific values ​​of the water content in a comparative example and in Example 1 in a demonstration test, together with the actual measured values. [Figure 20] FIG. 1 is a diagram comparing actual measured values ​​in a demonstration test with specific values ​​of water content in a comparative example and examples 1-3. [Figure 21] FIG. 11 is a diagram summarizing the errors of specific values ​​with respect to the actual measured values ​​in the comparative example and Examples 1-3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Hereinafter, a moisture content specifying system and a moisture content specifying method according to an embodiment will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components are designated by the same reference numerals to avoid redundant description.

[0038] [Moisture content determination system and moisture content determination method according to the embodiment] An example of a moisture content specifying system and a moisture content specifying method according to an embodiment will be described with reference to FIGS. Here, Fig. 1 is a plan view of an example of a belt conveyor material transport system to which an example of a moisture content specifying system according to an embodiment is applied, Fig. 2 is a perspective view of an example of a belt conveyor material transport system seen from the side of the belt conveyor, and Fig. 3 is a perspective view of an example of a belt conveyor material transport system seen from above at a midway position of the belt conveyor. Also, Fig. 4 is a diagram for explaining the variation of the top line of the material and the variation of the belt shape of the belt conveyor due to the variation of the transported soil volume, and Fig. 5 is a diagram for explaining the distribution of the contribution rate of the measurement value of the RI moisture meter in the cross section in the width direction of the belt.

[0039] The belt conveyor material transport system shown in Figs. 1 to 3 is a system for continuously transporting CSG material (gravel generated on-site) by belt conveyor in a CSG dam, for example, and mixing it with cement and water to produce construction material for the dam.

[0040] More specifically, when the CSG material is fed into the feeding hopper D1 in the X1 direction, the CSG material is continuously transported in the X2 direction to the mixer D4 by the belt conveyor 20. Water and cement are supplied to the mixer D4 from the water tank D2 and the cement tank D3, respectively, and the mixed material obtained by mixing the CSG material, water, and cement in the mixer D4 is discharged in the X3 direction via the belt conveyor B1.

[0041] A measurement cross-sectional position 32 is set midway along the belt conveyor 20, which continuously transports the CSG material to the mixer D4, where the moisture content (or moisture ratio) of the CSG material (hereinafter referred to as material M) is measured with an RI moisture meter. As shown in Figures 2 and 3, a measurement stand 31 is installed at this measurement cross-sectional position 32 so as to surround the belt conveyor 20, and a laser scanner 30 is installed at the center of the cross member above the measurement stand 31 (corresponding to the center in the width direction of the belt 22 of the belt conveyor 20).

[0042] In the measurement stand 31, below the belt conveyor 20, an RI moisture meter 40 and a laser distance meter 50 (see FIGS. 10 and 11 for both) are installed.

[0043] 2, a belt scale 60 for measuring the weight of material M is installed on the belt conveyor 20 upstream of the measurement stand 31 in the conveying direction. Furthermore, a calculation device 70 is installed near the belt conveyor 20 (in the illustrated example, on the side of the input hopper D1), and the moisture content identification system 10 is configured by the belt conveyor 20 that continuously conveys material M, the RI moisture meter 40 installed at the measurement cross-sectional position 32, the laser scanner 30, the laser distance meter 50, the belt scale 60, and the calculation device 70.

[0044] That is, the moisture content specifying system 10 is a system for specifying the moisture content of the material M that is continuously transported on the belt conveyor 20.

[0045] During the process of continuously transporting material M on the belt conveyor 20, the top surface of material M on the belt 22 takes on various three-dimensional shapes, and therefore, the top line in the two-dimensional cross-sectional shape of material M when passing through the measurement cross-sectional position 32 (the top line in the width direction of belt 22) can also change in various ways.

[0046] A change in the top line of the material M leads to a change in the weight of the material M, and the change in the weight of the material M may cause the shape of the belt 22 of the belt conveyor 20 to change in various ways.

[0047] When an RI moisture meter 40 is applied to such a belt conveyor 20 to measure the moisture content of material M, it is known that, due to the characteristics of the RI moisture meter 40, the volume and density of material M within or near the boundary of the measurement range, and variations in the distance between the RI moisture meter 40 and material M (the amount and distribution of water molecules within the detection range) affect the measurement value.

[0048] For example, as shown in Figure 4, fluctuations in the volume of soil being transported continuously on a belt conveyor cause the material top line in the width direction of the belt to fluctuate, and fluctuations in the volume (weight) of soil being transported cause the belt top line to fluctuate.

[0049] For example, as shown in Figure 4, if an RI moisture meter is installed below the center of the belt, fluctuations in the belt top line will cause the distance between the RI moisture meter and the material to fluctuate, resulting in a change in the measurement range.

[0050] In addition, as shown in Figure 5, it is known that the contribution rate of the measurement value of the RI moisture meter within the cross section of the belt in the width direction is highest near the RI moisture meter and decreases with increasing distance from the RI moisture meter.

[0051] Therefore, in the moisture content determination system 10, a correction is performed on the moisture content measurement value by the RI moisture meter 40 to take into account at least one of the following variations: the variation in the material top line of the material M at the measurement cross-sectional position 32, the variation in the shape of the belt 22 due to the variation in the weight of the material M, and the variation in the weight of the material M, thereby determining the moisture content of the material M passing through the measurement cross-sectional position 32 with high accuracy.

[0052] Regarding the corrections in the calculation device 70, the correction taking into account the fluctuation in the material top line of material M is the first correction, the correction taking into account the fluctuation in the shape of belt 22 due to the fluctuation in the weight of material M is the second correction, and the correction taking into account the fluctuation in the weight of material M is the third correction.

[0053] The types of corrections performed by the calculation device 70 include a form in which only the first correction is performed, a form in which only the second correction is performed, a form in which only the third correction is performed, a form in which the first and second corrections are performed, a form in which the first and third corrections are performed, a form in which the second and third corrections are performed, and a form in which all of the first, second, and third corrections are performed. The correction form selected by the construction manager, etc. is input into the calculation device 70, and the selected correction form is executed by the calculation device 70.

[0054] Next, the hardware configuration and functional configuration of the arithmetic device 70 constituting the moisture content identification system 10, and the flow of the first to third corrections (performed in the moisture content identification method) executed by the arithmetic device 70 will be described with reference to Figures 6 to 8. Here, Figure 6 is a diagram showing an example of the hardware configuration of the arithmetic device constituting an example of the moisture content identification system according to the embodiment, and Figure 7 is a diagram showing an example of the functional configuration of the arithmetic device constituting an example of the moisture content identification system according to the embodiment, together with peripheral devices. Also, Figure 8 is a flowchart for the case where three types of correction methods applied in the moisture content identification method according to the embodiment are performed consecutively.

[0055] 6, the arithmetic device 70 includes a CPU (Central Processing Unit) 71, a main storage device 72, an auxiliary storage device 73, a communication IF (interface) 74, and an input / output IF 75, which are interconnected by a connection bus 76. The main storage device 72 and the auxiliary storage device 73 are computer-readable recording media. Note that the above components may be provided separately, or some of the components may not be provided.

[0056] The CPU 71 is also called an MPU (Microprocessor) or a processor, and may be a single processor or a multiprocessor. The CPU 71 is a central processing unit that performs overall control of the arithmetic device 70, which is a computer. The CPU 71 provides functions that meet a predetermined purpose by, for example, expanding a program stored in the auxiliary storage device 73 in an executable manner in the working area of ​​the main storage device 72, and controlling peripheral devices through the execution of the program.

[0057] The main storage device 72 stores computer programs executed by the CPU 71, data processed by the CPU 71, and the like. The main storage device 72 includes, for example, a flash memory, a RAM (Random Access Memory), and a ROM (Read Only Memory). The auxiliary storage device 73 stores various programs and various data in a readable and writable recording medium, and is also called an external storage device. The auxiliary storage device 73 stores, for example, an OS (Operating System), various programs, various tables, and the like. The OS includes, for example, a communication interface program that transfers data to and from an external device connected via the communication IF 74. The external device includes, for example, a communication device (none of which are shown) provided in the RI moisture meter 40, the laser scanner 30, the laser distance meter 50, the belt scale 60, and the like. The arithmetic device 70 and various devices may be connected to each other via wires in addition to wireless communication so as to be able to transmit and receive data.

[0058] The auxiliary storage device 73 is used, for example, as a storage area that supplements the main storage device 72, and stores computer programs executed by the CPU 71, data processed by the CPU 71, etc. The auxiliary storage device 73 is a silicon disk including a non-volatile semiconductor memory (flash memory, EPROM (Erasable Programmable ROM)), a hard disk drive (HDD: Hard Disk Drive) device, a solid state drive device, etc. Examples of the auxiliary storage device 73 include drives for removable recording media such as a CD drive device, a DVD drive device, and a BD drive device, and examples of the removable recording media include a CD, a DVD, a BD, a USB (Universal Serial Bus) memory, and an SD (Secure Digital) memory card, etc.

[0059] The communication IF 74 is an interface with the network to which the arithmetic device 70 is connected. The communication IF 74 acquires, via the network, moisture content measurement values ​​(measurement data) by the RI moisture meter 40, material top line measurement values ​​relating to the top line of the material by the laser scanner 30, and belt top line measurement values ​​relating to the top line of the belt 22. In addition, it acquires distance measurement values ​​to the belt by the laser distance meter 50, and material weight measurement values ​​by the belt scale 60.

[0060] The arithmetic device 70 performs at least one of a first correction to a third correction based on various measurement values ​​acquired from other devices on the acquired moisture content measurement value, thereby specifying and displaying the moisture content.

[0061] The input / output IF 75 is an interface for inputting and outputting data between devices connected to the arithmetic device 70. For example, input devices such as a touch panel and a microphone are connected to the input / output IF 75. The arithmetic device 70 receives, via the input / output IF 75, operation instructions from an operator who operates the input device.

[0062] Further, a display device such as a liquid crystal panel (LCD: Liquid Crystal Display) or an organic EL panel (EL: Electroluminescence) and an output device such as a speaker are connected to the input / output IF 75. For example, the moisture content determined by the arithmetic unit 70 is displayed on the display device.

[0063] 7, the arithmetic device 70 provides various functions of at least an acquisition unit 82, a calculation unit 83, a correction unit 84, a display unit 85, and a storage unit 86 by executing a program by a CPU 71. At least a part of the above processing functions may be provided by a DSP (Digital Signal Processor), a GPU (Graphics Processing Unit), or the like, and similarly, at least a part of the above processing functions may be a dedicated LSI (large scale integration) such as an FPGA (Field-Programmable Gate Array), a numerical calculation processor, an image processing processor, or other digital circuits, or the like.

[0064] The acquisition unit 82 acquires moisture content measurement values ​​using the RI moisture meter 40 via the network, acquires material top line measurement values ​​relating to the top line of the material and belt top line measurement values ​​relating to the top line of the belt 22 using the laser scanner 30, acquires distance measurement values ​​to the belt using the laser distance meter 50, and acquires material weight measurement values ​​using the belt scale 60.

[0065] As shown in FIG. 9, a logarithmic approximation formula (calibration formula) relating to the correlation between the moisture content of locally generated gravel and the count rate ratio: Rm measured by an RI moisture meter is created and stored in advance in the memory unit 86.

[0066] The calculation unit 83 converts the moisture content measurement value (counting rate ratio: Rm) transmitted from the RI moisture meter 40 and acquired by the acquisition unit 82 into a moisture content (moisture content ratio) by applying it to this logarithmic approximation formula.

[0067] As shown in Figure 8, in the past, the moisture content measured by an RI moisture meter (counting rate ratio: Rm0) was directly converted through a calibration formula to obtain the RI moisture content: W RI However, when applied to materials that are continuously transported on a belt conveyor, it is not possible to determine the moisture content (moisture content) with high accuracy due to the various variable factors mentioned above.

[0068] The correction unit 84 has a first correction formula, a second correction formula, and a third correction formula shown in FIG. 8. After performing correction by applying the moisture content measurement value (counting rate ratio Rm0) to the selected correction formula, the corrected counting rate ratio is applied to the calibration formula to obtain the corrected RI moisture content: W RI ' is intended to identify the

[0069] The example shown in Fig. 8 is a correction form in which the first correction, the second correction, and the third correction are performed in that order. In this correction method, the count ratio after the first correction: Rm1 is calculated as Rm1 = G1 x Rm0 when the first correction coefficient is G1. Next, the count ratio after the second correction: Rm2 is calculated as Rm2 = G2 x Rm1 when the second correction coefficient is G2. Next, the count ratio after the third correction: Rm3 is calculated as Rm3 = G3 x Rm2 when the third correction coefficient is G3.

[0070] RI water content after the first to third corrections: W RI ' is W RI The measured moisture content is converted to moisture content (moisture content) using '=f(Rm3).

[0071] Before describing the details of the first to third corrections, the configuration of each device at the measurement cross-sectional position 32 will be described with reference to Fig. 10 and Fig. 11. Fig. 10 is a front view of each device at the measurement cross-sectional position, and Fig. 11 is a view taken along the line XI-XI in Fig. 10, showing each device at the measurement cross-sectional position from the side.

[0072] At the measurement cross-section position 32, a rectangular frame-shaped measurement stand 31 is installed so as to surround the belt conveyor 20. At the center position of the cross member below the measurement stand 31, the belt 22 constituting the belt conveyor 20 is disposed so as to be freely movable in its longitudinal direction, and an RI moisture meter 40 is installed below the belt 22 at the measurement cross-section position 32.

[0073] The RI moisture meter 40 is preferably a scattering type RI moisture meter, but other types of RI moisture meters may also be used.

[0074] A pair of support rollers 35 are disposed on the back side of belt 22 so as to sandwich measurement cross-sectional position 32 therebetween, supporting belt 22 while rotatably contacting the back side of belt 22 and sandwiching RI moisture meter 40 therebetween.

[0075] In addition, two laser distance meters 50 are arranged at positions corresponding to the two gaps between a pair of support rollers 35 and the RI moisture meter 40 located between them, and as shown in Figures 10 and 11, the laser emitted from the laser distance meter 50 is reflected in the Y2 direction on the back surface of the belt 22 through the gap, and the laser distance meter 50 receives the reflected laser to obtain a distance reference value related to the distance from the laser distance meter 50 to the back surface of the belt 22.

[0076] In addition, the distance to the back surface of the belt 22 when the belt conveyor 20 is not transporting the material M is measured in advance, and this is stored in the memory unit 86 as a distance reference value related to the distance to the back surface of the belt 22.

[0077] The calculation unit 83 calculates the ratio of the distance measurement value to the distance reference value, or the difference between the distance reference value and the distance measurement value, and stores the calculation result in the storage unit 86 .

[0078] The correction unit 84 corrects the moisture content measurement value (second correction) based on the calculation result stored in the storage unit 86. Here, a one-axis laser distance sensor, a 2D range sensor, or the like can be used as the laser distance meter.

[0079] Meanwhile, a laser scanner 30 is installed at the center position of the cross member above the measurement stand 31, and a laser is irradiated from the laser scanner 30 onto the material M in the Y1 direction, and the material top line of the material M (the top line in the width direction of the belt 22) is measured by receiving the reflected laser (material top line measurement value).

[0080] In addition, the distance to the top surface 22a of the belt 22 when the belt conveyor 20 is not transporting the material M is measured in advance, and this is stored in the memory unit 86 as the belt top line measurement value related to the top line of the belt 22.

[0081] The calculation unit 83 calculates the difference between the material top line measurement value and the belt top line measurement value stored in the memory unit 86, calculates a height distribution calculation value related to the height distribution of the two-dimensional cross-sectional shape of the material M at the measurement cross-sectional position 32, and stores the calculation result in the memory unit 86.

[0082] The correction unit 84 corrects the moisture content measurement value (first correction) based on the calculation result stored in the storage unit 86. Here, the laser scanner 30 may be a 2D range sensor, a 3D range sensor, or the like.

[0083] Furthermore, a belt scale 60 (see FIGS. 2 and 3) installed midway along the belt conveyor 20 measures the weight of the material M transported by the belt conveyor 20 (weight transported per hour).

[0084] For example, a weight reference value relating to the transported weight of the material and its moisture content are stored in the memory unit 86. The correction unit 84 corrects the moisture content measurement value based on the value obtained by multiplying the moisture content of the weight reference value by the ratio of the weight measurement value to the weight reference value (third correction).

[0085] Alternatively, this third correction may be a correction method in which a relational equation between the transported weight and the counting rate ratio change rate, which is the moisture content measurement value, is specified in advance and stored in memory unit 86, and correction unit 84 applies the weight measurement value to the relational equation to correct the moisture content measurement value.

[0086] Although not shown in the figure, the pair of support rollers 35 may be provided with a load cell, the transported weight may be measured by the load cell, and the weight reference value may be applied to the third correction.

[0087] Next, the first correction shown in Fig. 8 will be described in detail with reference to Fig. 12 to Fig. 16. Here, Fig. 12 to Fig. 16 are all explanatory diagrams for explaining the first correction.

[0088] As shown in Figure 12, the height distribution of the two-dimensional cross-sectional shape of the material at the measurement cross-sectional position 32 is calculated from the difference between the material top line M1 (transverse distribution) and the belt top line (the line on the belt top surface 22a), which is the reference plane.

[0089] Next, for multiple widthwise divided blocks (regions 1 to 3) divided according to the response characteristics of the RI moisture meter 40, a weighted sum of logarithmic approximation equations using the average material heights (h1 to h3) for each widthwise divided block is calculated, and this is set as the correction coefficient: G1.

[0090] There are various methods for dividing the width-wise divided blocks, but based on the inventors' experience and the ease of calibration, the boundaries were set at diameters of 120 mm, 240 mm, and 360 mm, centered on the Z axis (0 degree line) passing through the center of the laser scanner 30.

[0091] The reason for dividing the sample into multiple widthwise division blocks is based on the difference in the contribution rate (weight of the influence on the RI measurement value) according to the position in the measurement cross section (see Figure 5). The contribution rate of each widthwise division block is applied as a weighting coefficient in the above correction formula.

[0092] Next, as shown in Figure 13, for each widthwise divided block (regions 1 to 3), the count rate ratio when the average material height was 50 mm was used as the reference value, and by changing the material height, it was confirmed how the count rate ratio changed against the reference value, and the relationship between the average material height of each region 1 to 3 and the count ratio change rate was obtained.

[0093] As is clear from Figures 13(a) to (c), when the moisture content and density are kept constant and the average material height of each region is changed, the relationship between the average material height and the ratio to the reference Rm shows the strongest correlation when logarithmic approximation is used.

[0094] Next, the contribution rate of each region was confirmed by the following experiment, as shown in Fig. 14. First, three types of steel pipes (diameters 120 mm, 240 mm, and 360 mm) with diameters corresponding to the widths of each region and a sample with a homogeneous moisture content were prepared.

[0095] Next, the material height for each area is set to three levels, h = 3 cm, 5 cm, and 10 cm, and the confirmation range is divided into nine blocks, [area-number of levels] = [1-1] to [1-3]. As shown in Figure 14, the shape of the horizontal plane is constant, either circular or Baumkuchen-like, and the height can be freely set within the expected material height fluctuation range.

[0096] As shown in FIG. 15A, first, the counting rate is obtained when all blocks are empty (=11.0 cps).

[0097] Next, the count rate is obtained with the sample filled in [1-1] (=24.3 cps). Here, the increase in the count rate due to filling [1-1] is 24.3-11.0=13.3 cps.

[0098] In the same manner, fill the sample up to the heights of [1-2] and [1-3] and determine the increase in count rate for each.

[0099] Next, as shown in Fig. 15B, the count rate is obtained with the sample filled in [2-1] (=33.2 cps). Here, the increase in the count rate due to filling in [2-1] is 33.2-27.1 (at the total height of region 1) = 6.1 cps.

[0100] In the same manner, fill the sample up to the height of [2-2] and [2-3] and calculate the increase in the count rate for each.

[0101] Finally, as shown in Fig. 15C, the count rate is obtained with the sample filled in [3-1] (=45.3 cps). Here, the increase in the count rate due to filling in [3-1] is 45.3-41.8 (at the total height of regions 1 and 2) = 3.5 cps.

[0102] In the same manner, fill the sample up to the heights of [3-2] and [3-3] and calculate the increase in count rate for each.

[0103] The count rate of each width-direction divided block is calculated by the above procedure. As shown in Figure 16, the sum of the count rates for each region is 16.1 for region 1, 14.7 for region 2, and 8.5 for region 3.

[0104] Since the counting rate for all regions is 39.3, the ratio of each region to this value is taken as the contribution rate and multiplied as the weighting coefficient of the correction formula for the first correction. That is, in the illustrated example, the weighting coefficient for region 1 is W1=0.410, the weighting coefficient for region 2 is W2=0.374, and the weighting coefficient for region 3 is W3=0.216, and these are multiplied by the correction formula.

[0105] In the first correction, a height distribution calculation value relating to the height distribution of the two-dimensional cross-sectional shape of the material at the measured cross-sectional position is calculated based on the difference between the material top line measurement value and the belt top line measurement value, and the moisture content measurement value is corrected based on the height distribution measurement value.

[0106] In this case, for each widthwise divided block in which the two-dimensional cross-sectional shape is divided into multiple blocks in the width direction of the belt, the contribution rate of each widthwise divided block to the overall moisture content of the two-dimensional cross-sectional shape is calculated, the product of the approximation of the height distribution of each widthwise divided block and the contribution rate is calculated, the sum of the products of all the widthwise divided blocks is calculated to obtain a first correction coefficient, and the product of the moisture content measurement value and the first correction coefficient is calculated.

[0107] More specifically, the contribution rate of a width direction divided block is calculated as the sum of the contribution rates of a plurality of height direction divided blocks obtained by further dividing the width direction divided block in the height direction.

[0108] Next, the second correction shown in Fig. 8 will be described in detail with reference to Fig. 17. Here, Fig. 17 is an explanatory diagram for explaining the second correction.

[0109] As shown in Figure 17, the difference between the distance from the sensor to the underside of the belt obtained by the laser range finder and the reference value (distance during idle operation) was used as a variable to confirm the relationship between the ratio to the reference Rm and the moisture content of the collected sample.

[0110] As a result, the second correction coefficient: G2 was defined by the second-order polynomial approximation equation that showed the strongest correlation.

[0111] In the second correction, the distance to the back surface of the belt forming the belt conveyor is measured as the distance measurement value, and the moisture content measurement value is corrected according to the ratio of the distance measurement value to a distance reference value for distance, or the difference between the distance reference value and the distance measurement value.

[0112] In this case, the distance reference value is the distance to the belt when no material is loaded on the belt, and the ratio of the measured distance value to the distance reference value is calculated as the second correction coefficient, but the method of deriving this second correction coefficient also includes a method of using the difference described above as a variable and calculating the second correction coefficient from the relational equation between the ratio to the standard Rm and the moisture content of the collected sample.The second correction is then performed by calculating the product of the measured moisture content value and the second correction coefficient.

[0113] Next, the third correction shown in Fig. 8 will be described in detail with reference to Fig. 18. Here, Fig. 18 is an explanatory diagram for explaining the third correction.

[0114] As shown in FIG. 18, it was confirmed how the count rate ratio changed relative to the standard in response to changes in the transported weight obtained by the belt scale.

[0115] In the third correction, the weight of the material transported by the belt conveyor is measured as a weight measurement value, and the moisture content measurement value is corrected according to the ratio of the weight measurement value to a weight reference value for weight.

[0116] In this case, the ratio of the weight measurement value to the weight reference value is set as the third correction coefficient, and the method of deriving this third correction coefficient also includes a method of obtaining the third correction coefficient based on the rate of change of the counting rate ratio to the reference for the change in the transported weight obtained by the belt scale.The third correction is then performed by calculating the product of the moisture measurement value and the third correction coefficient.

[0117] According to the moisture content determining system 10 and moisture content determining method described above, when material M is transported by belt conveyor 20, even if RI moisture meter 40 is applied in an environment where the measurement conditions and properties of the object to be measured fluctuate, the moisture content can be determined continuously with high accuracy.

[0118] [Demonstration test] Next, the contents and results of a demonstration test carried out by the present inventors to confirm the determination accuracy of the moisture content determining system will be described.

[0119] In this test, a dynamic test was conducted on the standard cross section of the belt conveyor of a belt conveyor material transport system, using a mixture of riverbed gravel and crushed sand (80-0mm). Specifically, the moisture content of the transported material was continuously obtained and compared with the moisture content of the collected sample (JIS method). In addition, support rollers were placed upstream and downstream of the RI moisture meter to reduce fluctuations in the underside of the belt and suppress the occurrence of errors in the second correction. It has been confirmed that the installation of these support rollers can reduce fluctuations of about 5mm to 0.3mm.

[0120] In this test, a method in which the first correction and the second correction are performed sequentially is set as Example 1, a method in which only the first correction is performed is set as Example 2, a method in which only the second correction is performed is set as Example 3, and a method without correction is set as Comparative Example.

[0121] The test results are shown in Figures 19 to 21. Specifically, Figure 19 shows the specific values ​​of the water content of the Comparative Example and Example 1 in the verification test together with the actual measured values, and Figure 20 compares the actual measured values ​​in the verification test with the specific values ​​of the water content of the Comparative Example and Examples 1-3. Also, Figure 21 is a summary of the errors of the specific values ​​of the Comparative Example and Examples 1-3 with respect to the actual measured values.

[0122] From FIG. 19, it can be seen that, with regard to the time series changes in the measurement values, the correction in Example 1 significantly suppresses the variation in the measurement values, which is mainly due to the fluctuation in material height, compared to the comparative example, and the fluctuation in the moisture content of the collected samples is well captured.

[0123] Next, from FIG. 20 and FIG. 21, it is confirmed that the average value of the measurement error is reduced from 1.37% in the comparative example to 0.34% in Examples 1 and 2, which is an improvement in accuracy of about four times.

[0124] Moreover, in Example 3, the results show that the error to be corrected itself is reduced by suppressing the belt fluctuation with the support rollers, confirming the effectiveness of the measure to suppress the belt fluctuation with the support rollers.

[0125] As a result of accuracy verification through this test, it was confirmed that measurement accuracy can be ensured even for thin layer cross sections with material heights of 40 mm or less.

[0126] From the above, the moisture content determination system 10 is applicable to general belt conveyors in general and has high versatility, so it is expected to contribute to improving the productivity of quality control in earthworks. Specifically, it is suitable for aggregate performance and quarrying, production of cement-based improved soil, and material management of embankments and backfill soil.

[0127] In addition to determining the moisture content of materials transported on a conveyor belt, this method can also be used to determine the moisture content of randomly placed piles of soil and sand using a hydraulic excavator, or to fill a hopper of a fixed capacity with soil and sand, measure the weight of the material using a load cell, and monitor density fluctuations.

[0128] In addition, the present invention is not limited to the configuration shown here, and may be implemented in other embodiments in which other components are combined with the configurations and the like of the above-mentioned embodiment. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined according to the application form. [Explanation of symbols]

[0129] 10: Moisture content determination system 20:Conveyor belt 22: Belt 22a: Top surface 30: Laser scanner 31: Measurement stand 32: Measurement cross-section position 35: Support roller 40:RI moisture meter 50: Laser range finder 60: Belt scale 70: Arithmetic device 82: Acquisition Department 83: Calculation Department 84: Correction section 85:Display section 86: Storage section M: Material M1: Material top line D1: Input hopper D2: Water tank D3: Cement tank D4: Mixer B1: Belt conveyor

Claims

1. A moisture content determining system for determining a moisture content of a material conveyed by a belt conveyor, comprising: The belt conveyor; an RI moisture meter disposed on a back side of a belt forming the belt conveyor and measuring the moisture content of the material; A laser scanner is disposed on the surface side of the belt and measures both the top line of the belt and the top line of the material at a measurement cross-sectional position perpendicular to the width direction of the belt; A computing device, The computing device includes: Obtain a moisture content measurement value using the RI moisture meter; A material top line measurement value relating to the top line of the material and a belt top line measurement value relating to the top line of the belt are obtained; A height distribution calculation value relating to the height distribution of the two-dimensional cross-sectional shape of the material at the measurement cross-sectional position is calculated based on the difference between the material top line measurement value and the belt top line measurement value; A moisture content determining system, comprising: a first correction for correcting the moisture content measurement value based on the height distribution calculation value, thereby determining the moisture content of the material.

2. The computing device includes: A height distribution reference value relating to the height distribution of the two-dimensional cross-sectional shape is stored; 2. The moisture content specifying system according to claim 1, wherein the first correction is performed to correct the moisture content of the material in accordance with a ratio of the height distribution calculation value to the height distribution reference value.

3. The computing device includes: storing a contribution rate of each width direction divided block to an entire moisture content of the two-dimensional cross-sectional shape for each width direction divided block obtained by dividing the two-dimensional cross-sectional shape into a plurality of width direction divided blocks in the width direction of the belt; A product of the approximation expression of the height distribution in each width direction divided block and the contribution rate is calculated, and a sum of the products of all the width direction divided blocks is calculated to obtain a first correction coefficient; 3. The moisture content specifying system according to claim 2, wherein in the first correction, a product of the moisture content measurement value and the first correction coefficient is calculated.

4. The moisture content determination system according to claim 3, characterized in that the contribution rate of the width-direction divided block is calculated as the sum of the contribution rates of a plurality of height-direction divided blocks obtained by further dividing the width-direction divided block into a plurality of height-direction divided blocks.

5. a pair of support rollers disposed on the back side of the belt, supporting the belt while rotatably contacting the back side of the belt, and sandwiching the RI moisture meter therebetween; 2. The moisture content determining system according to claim 1, wherein the measurement cross-sectional position is set directly above the RI moisture meter.

6. Further, a laser distance meter is provided on the back side of the belt to measure a distance to the back side of the belt, The computing device includes: storing a distance reference value relating to the distance to the back surface of the belt; Obtaining a distance measurement value by the laser range finder; The moisture content determining system according to claim 5, further comprising a second correction for correcting the moisture content of the material in accordance with a ratio of the distance measurement value to the distance reference value or a difference between the distance reference value and the distance measurement value, thereby determining the moisture content of the material.

7. The moisture content determining system according to claim 6, characterized in that the two laser distance meters are disposed at positions corresponding to two gaps between the pair of support rollers and the RI moisture meter located therebetween.

8. The support roller is provided with a load cell, or a belt scale is provided on the back side of the belt, and the weight of the material is measured by the load cell or the belt scale. The computing device includes: A weight measurement value obtained by the load cell or the belt scale is obtained, storing a weight reference value of the material to be conveyed; The moisture content determining system according to claim 7, further comprising a third correction for correcting the moisture content of the material in accordance with a ratio of the weight measurement value to the weight reference value, thereby determining the moisture content of the material.

9. A moisture content determination method for determining a moisture content of a material conveyed by a belt conveyor, comprising the steps of: Measure the moisture content of the material conveyed by the belt conveyor to obtain a moisture content measurement value; The top line of the belt and the top line of the material are measured at a measurement cross-sectional position perpendicular to the width direction of the belt forming the belt conveyor, and the measured values ​​are set as a belt top line measurement value and a material top line measurement value. A moisture content determination method, characterized in that a height distribution calculation value relating to the height distribution of the two-dimensional cross-sectional shape of the material at the measurement cross-sectional position is calculated based on the difference between the material top line measurement value and the belt top line measurement value, and the moisture content of the material is determined by a first correction that corrects the moisture content measurement value based on the height distribution measurement value.

10. 10. The moisture content determining method according to claim 9, wherein the first correction corrects the moisture content of the material in accordance with a ratio of the height distribution calculation value to a height distribution reference value relating to the height distribution of the two-dimensional cross-sectional shape.

11. For each of the widthwise divided blocks into which the two-dimensional cross-sectional shape is divided in the width direction of the belt, a contribution rate of each widthwise divided block to the entire moisture content of the two-dimensional cross-sectional shape is calculated; The product of the approximation expression of the height distribution of each width-direction divided block and the contribution rate is calculated, and the sum of the products of all the width-direction divided blocks is calculated to obtain a first correction coefficient; 11. The moisture content specifying method according to claim 10, wherein the first correction comprises calculating a product of the moisture content measurement value and the first correction coefficient.

Images