Soil improvement material identification device and soil improvement material identification method

Abstract

To provide a soil improvement material identification device 1 and a soil improvement material identification method that improve identification accuracy through robust measurement based on a ratio of comparing multiple temperature change rates.SOLUTION: A soil improvement material identification device 1 includes: a heating unit that heats a surface of cultivation soil So with approximately constant intensity; a surface temperature information acquisition unit that sequentially acquires the surface temperature information of the cultivation soil So over time, linking the same to the square root of the time based on the start time of heating; a temperature change rate information acquisition unit that acquires the first temperature change rate information of the surface temperature with respect to a first section based on the square root of the first time and the square root of the second time, and the second temperature change rate information of the surface temperature with respect to the square root of a second section based on the square root of the third time and the square root of the fourth time; and a soil improvement material identification unit that identifies the soil and the soil improvement materials contained in the surface of the cultivation soil So on the basis of the ratio between the change rate included in the first temperature change rate information and the change rate included in the second temperature change rate information.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a soil improvement material identification device and a soil improvement material identification method for identifying soil and soil improvement materials contained in cultivation soil. [Background technology]

[0002] Soil improvement materials in cultivation soil play important roles in terms of air permeability, water retention, drainage, and material circulation of carbon, nitrogen, etc. Therefore, various techniques have been researched to identify the types of organic or inorganic substances and their ratios (volume ratios, etc.) as soil improvement materials in cultivation soil. One example of this technique is a chemical technique (Non-Patent Document 1) that utilizes the weight loss when a sample in cultivation soil is burned and analyzes the gas components generated during combustion. However, these techniques have problems in that they require time and effort for sample collection, pretreatment, and analysis, and are destructive analyses. In addition, they are not suitable for on-site measurement, and it is difficult to measure coarse soil improvement materials (grain size 2 mm or more) or wide areas.

[0003] In response to this problem, non-destructive and simple evaluation methods have also been researched. One example of this technology is a method in which the content is determined from the brightness of the soil color by utilizing the fact that organic matter has a blackish hue (Non-Patent Document 2). However, this method has problems such as lack of objectivity and quantification because it is roughly classified according to a graded brightness standard, and the evaluation work requires skill because it is a visual method on site. A method has also been proposed to estimate the amount of organic components by comparing the color of a color chart with that of the cultivation soil (Non-Patent Document 3), but there are problems with the measurement accuracy, such as changes in the color of the sample due to the temperature and humidity of the measurement environment and differences in appearance depending on the lighting conditions.

[0004] In order to cope with such problems of measurement accuracy, methods that focus on the thermal properties of the target material are being researched. Patent Document 1 discloses a technology for identifying the location of the foreign matter by heating the target material, such as foodstuffs containing foreign matter, and measuring the rate of temperature drop of each target material after heating. Patent Document 2 discloses a technology for determining the material by comparing the surface temperature of plastic irradiated with infrared rays with a reference value set in advance for each material, or by the measured temperature difference between a reference material and a different material. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 8-131966 [Patent Document 2] Japanese Patent Application Publication No. 9-297114 [Non-Patent Document 1] Committee of edition for method for soils and environments analysis: "Method for soils and environments analysis" (1997) [Non-Patent Document 2] Japanese Society of Pedologists, revised edition, Soil Survey Handbook (2021) [Non-Patent Document 3] Moritsuka et al. "Soil color analysis for statistically estimating total carbon total nitrogen and active iron contents in Japanese agricultural soils" Soil Science and Plant Nutrition, 60 (2014) 475-485. Summary of the Invention [Problem to be solved by the invention]

[0006] According to the sorting device disclosed in Patent Document 1, by using a method of measuring the difference in intensity of the infrared spectrum emitted with the temperature change of the material, even if the objects to be sorted are difficult to be sorted, such as foodstuffs and impurities, which have similar shapes, dimensions, weights, and electrical properties, it is possible to reliably sort and remove the impurities at a high removal rate by utilizing the difference in thermal properties. In addition, according to the discrimination device disclosed in Patent Document 2, material discrimination can be performed easily, quickly, and continuously by measuring the temperature difference of the surface of the plastic to be measured irradiated with a certain amount of infrared light. However, since the devices disclosed in Patent Document 1 and Patent Document 2 are simply methods for measuring the difference in infrared spectrum intensity or the difference in surface temperature of multiple materials at one time, the accuracy of the measurement is easily affected by the difference in absorptivity and emissivity due to dirt or attachments on the surface of the target material. In addition, the method of simply measuring the temperature or the rate of change of temperature changes depending on the amount of heat or heat dissipation, and therefore has low robustness, such as the need to review the reference value depending on the measurement environment and measurement conditions. As a result of the above, the devices disclosed in Patent Document 1 and Patent Document 2 have a problem in that they cannot improve the accuracy of identifying soil improvement materials.

[0007] The present invention has been devised in consideration of the above-mentioned problems, and its object is to provide a soil improvement material identification device and a soil improvement material identification method that improve the accuracy of identifying soil improvement materials through robust measurements based on the ratio when multiple temperature change rates are compared. [Means for solving the problem]

[0008] The soil improvement material identification device according to a first aspect of the present invention is a soil improvement material identification device for identifying soil and soil improvement materials contained in cultivation soil, and includes a heating unit which heats the surface of the cultivation soil at a substantially constant intensity, a surface temperature information acquisition unit which, based on the start time of heating by the heating unit, acquires surface temperature information indicating the surface temperature of the cultivation soil in a chronological order by linking it to time information indicating the square root of that time, and a rate of change in the surface temperature for a first interval based on the square root of a first time and the square root of a second time later than the first time, which are included in the time information acquired by the surface temperature information acquisition unit. and second temperature change rate information indicating the rate of change of the surface temperature for a second interval based on the square root of a third time after the first time included in the time information and the square root of the second time and a fourth time after the third time included in the time information; and a soil improvement material identification unit that identifies the soil and the soil improvement material contained on the surface of the cultivation soil based on the ratio between the rate of change included in the first temperature change rate information acquired by the temperature change rate information acquisition unit and the rate of change included in the second temperature change rate information.

[0009] The soil improvement material identification device of the second invention is characterized in that, in the first invention, the surface temperature information acquisition unit acquires a surface temperature image showing the surface temperature information in a two-dimensional image, the temperature change rate information acquisition unit acquires the first temperature change rate information and the second temperature change rate information for each of a plurality of image blocks generated by dividing the surface temperature image, and the soil improvement material identification unit identifies the ratio of the number of image blocks of the soil improvement material identified for each image block to the number of image blocks corresponding to the cultivation soil based on the ratio of the change rate included in the first temperature change rate information to the change rate included in the second temperature change rate information.

[0010] The soil improvement material identification device of the third invention is characterized in that, in the first invention, the surface temperature information acquisition unit acquires a surface temperature image showing the surface temperature information in a two-dimensional image, the temperature change rate information acquisition unit acquires the first temperature change rate information and the second temperature change rate information for each of a plurality of image blocks generated by dividing the surface temperature image, and the soil improvement material identification unit identifies the relative position of the soil improvement material identified for each image block based on the first temperature change rate information and the second temperature change rate information with respect to the surface temperature image.

[0011] The soil improvement material identification device in the fourth invention is characterized in that, in any of the first to third inventions, the soil improvement material identification unit refers to a database in which reference ratio information corresponding to ratio information indicating the ratio between the first temperature change rate information and the second temperature change rate information acquired by the temperature change rate information acquisition unit, and reference soil improvement material identification information corresponding to soil improvement material identification information indicating information identifying the soil improvement material, are pre-linked, and the soil improvement material is estimated based on the soil improvement material identification information corresponding to the ratio information.

[0012] The soil improvement material identification method of the fifth invention is a soil improvement material identification method for identifying soil and soil improvement materials contained in cultivation soil, and is characterized by having the following features: a heating step of heating the surface of the cultivation soil at a substantially constant intensity; a surface temperature information acquisition step of linking surface temperature information indicating the surface temperature of the cultivation soil with time information indicating the square root of the time based on the start time of heating in the heating step and acquiring surface temperature information in chronological order sequentially; a temperature change rate information acquisition step of acquiring first temperature change rate information indicating the rate of change of the surface temperature with respect to the square root of a first time contained in the time information acquired by the surface temperature information acquisition step, and second temperature change rate information indicating the rate of change of the surface temperature with respect to the square root of a second time contained in the time information and which is later than the first time; and a soil improvement material identification step of identifying the soil and the soil improvement materials contained on the surface of the cultivation soil based on the ratio of the change rate contained in the first temperature change rate information acquired by the temperature change rate information acquisition step to the change rate contained in the second temperature change rate information. Effect of the Invention

[0013] According to the first to fourth inventions, the apparatus includes a temperature change rate information acquisition unit that acquires first temperature change rate information indicating the rate of change of the surface temperature for the first interval and second temperature change rate information indicating the rate of change of the surface temperature for the second interval, and a soil improvement material identification unit that identifies the soil and soil improvement materials contained in the surface of the cultivation soil based on the ratio between the rate of change contained in the first temperature change rate information and the rate of change contained in the second temperature change rate information. Therefore, it is possible to perform highly robust identification based on the ratio obtained by comparing multiple temperature change rates. This makes it possible to improve the accuracy of identifying soil improvement materials in the cultivation soil. Here, the term "high robustness" refers to a characteristic that is not easily affected by the surface state of the soil and soil improvement materials as specimens, the measurement environment, or the measurement conditions.

[0014] In particular, according to the second aspect of the invention, the temperature change rate information acquisition unit acquires first and second temperature change rate information for each of a plurality of image blocks, and the soil improvement material identification unit identifies the ratio of the number of image blocks containing the soil improvement materials identified for each image block based on the first and second temperature change rate information to the number of image blocks corresponding to the cultivation soil. This allows for highly robust identification of the proportion of the soil improvement materials in the image based on the ratio obtained by comparing multiple temperature change rates. This improves the convenience of identifying soil improvement materials in the cultivation soil.

[0015] In particular, according to the third aspect of the invention, the temperature change rate information acquisition unit acquires first and second temperature change rate information for each of a plurality of image blocks, and the soil improvement material identification unit identifies the relative position in the surface temperature image of the image block of the soil improvement material identified for each image block based on the first and second temperature change rate information. Therefore, it is possible to perform highly robust identification of the relative position of the soil improvement material in the image based on the ratio of the multiple temperature change rates. This improves the convenience of identifying the soil improvement material in the cultivation soil.

[0016] In particular, according to the fourth aspect of the present invention, the soil improvement material identification unit refers to a database in which reference ratio information corresponding to the ratio information indicating the ratio between the first temperature change rate information and the second temperature change rate information and reference soil improvement material identification information corresponding to the soil improvement material identification information are linked in advance, and estimates the soil improvement material based on the soil improvement material identification information corresponding to the ratio information. Therefore, it is possible to make a highly robust estimation of the details of the soil improvement material based on the ratio obtained by comparing multiple temperature change rates. This improves the convenience of estimating the soil improvement material in the cultivation soil.

[0017] According to the fifth aspect of the present invention, the method includes a temperature change rate information acquisition step of acquiring first temperature change rate information indicating the rate of change of the surface temperature for a first interval and second temperature change rate information indicating the rate of change of the surface temperature for a second interval, and a soil improvement material identification step of identifying the soil and soil improvement materials contained in the surface of the cultivation soil based on the ratio between the first temperature change rate information and the second temperature change rate information. This allows for highly robust identification based on the ratio obtained by comparing multiple temperature change rates. This allows for improved accuracy in identifying soil improvement materials in the cultivation soil. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 is a schematic diagram showing an example of the configuration of a soil improvement material identification device in the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram showing an example of a detailed configuration of the soil improvement material identification device in the first embodiment. [Diagram 3] FIG. 3 is a schematic diagram showing an example of the configuration of the soil improvement material identification device in the first embodiment. [Figure 4] FIG. 4 is a flowchart showing an example of the operation of the soil improvement material identification device in the first embodiment. [Diagram 5] FIG. 5 is a schematic diagram showing an example of information related to the operation of the soil improvement material identification device in the first embodiment. [Figure 6] FIG. 6(a) is a schematic diagram showing an example of operating conditions of the soil improvement material identification device in the first embodiment, and FIGS. 6(b) to 6(d) are schematic diagrams showing an example of information acquired in conjunction with the operation of the soil improvement material identification device. [Figure 7] FIG. 7(a) is a schematic diagram showing a modified example of information related to the operation of the soil improvement material identification device in the first embodiment, and FIG. 7(b) and FIG. 7(c) are schematic diagrams showing modified examples of information acquired in conjunction with the operation of the soil improvement material identification device. [Figure 8] FIG. 8 is a schematic diagram showing a modified example of information acquired in conjunction with the operation of the soil improvement material identifying device in the first embodiment. [Figure 9]9(a) and 9(b) are schematic diagrams showing an example of information related to the operation of the soil improvement material identifying device in the second embodiment. [Figure 10] FIG. 10 is a graph showing an example of actual measurement values ​​of the identification results for charcoal using the soil improvement material identification device. [Figure 11] FIG. 11 is a graph showing an example of an approximation curve of the identification result for charcoal by the soil improvement material identification device. [Figure 12] FIG. 12 is a graph showing an example of actual measurement values ​​of the identification results for charcoal soil using the soil improvement material identification device. [Figure 13] FIG. 13 is a graph showing an example of actual measurement values ​​of the identification results for rice straw obtained by the soil improvement material identification device. [Figure 14] FIG. 14 is a graph showing an example of an approximation curve of the identification result for rice straw obtained by the soil improvement material identification device. [Figure 15] FIG. 15 is a graph showing an example of actual measurement values ​​of the identification results for soil for rice straw using the soil improvement material identification device. [Figure 16] FIG. 16 is a graph showing an example of actual measured values ​​of the identification results for perlite using the soil improvement material identification device. [Figure 17] FIG. 17 is a graph showing an example of an approximation curve of the identification result for perlite by the soil improvement material identification device. [Figure 18] FIG. 18 is a graph showing an example of actual measurement values ​​of the identification results for perlite soil using the soil improvement material identification device. [Figure 19] FIG. 19 is a graph showing an example of the identification accuracy of the soil improvement material identification device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, an example of a soil improvement material identification device 1 and a soil improvement material identification method as an embodiment of the present invention will be described in detail with reference to the drawings. Note that the components in each drawing are shown diagrammatically for the purpose of explanation, and for example, the size of each component and the size comparison between the components may differ from those shown in the drawings.

[0020] (First embodiment: soil improvement material identification device 1) An example of a soil improvement material identification device 1 in this embodiment will be described with reference to the drawings.

[0021] 1, the soil improvement material identifying device 1 includes a control device 2, a measuring device 3, and a heating device 4. In the soil improvement material identifying device 1, for example, the control device 2, the measuring device 3, and the heating device 4 are connected via a transmission line 9. The soil improvement material identifying device 1 may be a portable device in which the control device 2, the measuring device 3, and the heating device 4 are integrated, for example.

[0022] The soil improvement material identification device 1 identifies the soil and soil improvement materials contained in the cultivation soil S. In detail, the soil improvement material identification device 1 accepts various conditions input by the user U in advance, for example, in the control device 2, and then heats the surface of the cultivation soil S at a substantially constant intensity via the heating device 4 by operation at the work site where the cultivation soil S is present. Thereafter, the soil improvement material identification device 1 performs a process of linking the surface temperature of the heated cultivation soil S with information indicating the square root of time via the measuring device 3 and sequentially acquiring the surface temperature of the heated cultivation soil S in a chronological order, and acquiring a temperature change rate indicating the change rate of the surface temperature for a section based on the square root of multiple times. As a result, the soil improvement material identification device 1 can identify soil improvement materials such as soil (soil) and porous materials contained in the surface of the cultivation soil S based on the ratio of the multiple acquired temperature change rates. Here, the user U refers to a person who operates the soil improvement material identification device 1 at the work site. The user U can check the identification result of the soil improvement material identification device 1 at the work site, for example, via the control device 2.

[0023] One of the features of the soil improvement material identification device 1 is that it can obtain multiple temperature change rates that indicate the rate of change of the surface temperature for intervals based on the square roots of multiple times, and can identify the soil and soil improvement materials contained in the surface of the cultivation soil Sо based on the ratio of these. Therefore, compared to the conventional technology using destructive testing, it is possible to identify the soil and the soil improvement materials regardless of the particle size or measurement range. In addition, since multiple temperature change rates are compared, it is less affected by the surface state of the soil and soil improvement materials that are the specimens, the measurement environment, or the measurement conditions, and so-called highly robust identification can be performed. This can improve the identification accuracy of the soil improvement materials in the cultivation soil Sо. In addition, since the soil improvement material identification device 1 does not require testing using an external device, it can quickly identify the soil and the soil improvement materials at the work site. This can improve the convenience of identifying the soil improvement materials in the cultivation soil Sо.

[0024] Furthermore, the soil improvement material identification device 1 is capable of performing highly robust identification that is less susceptible to the effects of the surface condition of the soil improvement material, compared to conventional techniques that use non-destructive testing to identify materials based on the brightness or color of the cultivation soil S. This allows for improved identification accuracy for soil improvement materials in the cultivation soil S. Furthermore, the soil improvement material identification device 1 is capable of performing highly robust identification that is less susceptible to the effects of differences in absorptivity and emissivity due to dirt or attachments on the surface of the soil improvement material, compared to conventional techniques that use non-destructive testing to identify materials based on the rate of temperature drop after heating the cultivation soil S or the measured temperature difference between materials. This allows for improved identification accuracy for soil improvement materials in the cultivation soil S.

[0025] The principle by which the soil improvement material identification device 1 identifies the soil improvement materials in the cultivation soil S0 based on the temperature change rate can be explained as follows.

[0026] When the heating device 4 heats the cultivation soil Sо with a substantially constant intensity (step heating), the irradiation intensity does not change over time after heating begins, so a constant heat flux is applied to the cultivation soil Sо from the surface. When the surface of the cultivation soil Sо that is the measurement target of the soil improvement material identification device 1 is heated, heat is only transmitted from the surface in the depth direction, so it can be considered as one-dimensional heat conduction. Furthermore, because the cultivation soil Sо is mainly composed of soil with low thermal diffusivity, changes in temperature over time do not affect the entire object over a considerable period of time.

[0027] From the above, this heat transfer phenomenon occurs when the heat flux q from the surface s [W / m 2 Here, when the initial temperature is uniform at T0 [K], the heat conduction equation, initial conditions, and boundary conditions can be expressed by the following equations (1) to (3), respectively.

[0028]

number

[0029] Here, T is temperature [K], t is time [s], and α (= k / ρc) is thermal diffusivity [m 2 / s], k is thermal conductivity [W / (m K)], ρ is density [kg / m 3 ], c is the specific heat [J / (kg K)]. Also, x is the depth [m] from the surface along the depth direction that is approximately perpendicular to the surface of the cultivation soil Sо. In this case, the temperature [K] of the cultivation soil Sо is expressed by the following formula (4). Note that erfc is the complementary error function.

[0030]

number

[0031] In addition, because the position of the surface of the cultivation soil S corresponds to the position "x=0", the change in surface temperature over time can be calculated by substituting "x=0" in equation (4) as follows: Here, e is the thermal effusivity.

[0032]

number

[0033] According to equation (5), the surface temperature T of the soil S is calculated by the heat flux q s When the density ρ, specific heat c, and thermal conductivity k of the cultivation soil S are constant, it is proportional to the square root of time, and the slope is proportional to the inverse of the thermal effusivity.

[0034] In addition, because the thermal properties of each soil improvement material are different, the temperature change with respect to the square root of time is different. For example, for the soil contained in the cultivation soil S, the temperature rises proportionally to the square root of time in a heating environment of approximately constant intensity. On the other hand, for organic matter having a porous structure, such as rice straw and charcoal, contained in the cultivation soil S, the temperature rise with respect to the square root of time becomes gradually gentler in a heating environment of approximately constant intensity. According to this property, by measuring the slope of the temperature rise with time at multiple points in a heating environment of approximately constant intensity and confirming that the earlier slope is smaller than the later slope, it is possible to identify soil improvement materials made of porous materials.

[0035] In other words, the soil improvement material identification device 1 calculates at least two or more slopes of the temperature versus the square root of the time measured by the measuring equipment 3, and can identify the material as soil if there is no difference between the two or more slopes, and as porous material if there is a difference.

[0036] In this embodiment, separately from the soil improvement material identifying device 1, the control device 2 may be externally connected to a server that performs input related to the operation control of the measuring device 3 and the heating device 4 and outputs the operation results.

[0037] <Control device 2> The control device 2 controls the operations of the measuring device 3 and the heating device 4. As the control device 2, for example, a known electronic device such as a laptop (notebook) PC, a desktop PC, a tablet terminal, a smartphone, etc. When the control device 2 is configured as a portable soil improvement material identification device 1 integrated with the measuring device 3 and the heating device 4, for example, a microcontroller or a single board computer may be used.

[0038] 2(a), the control device 2 includes a housing 20, a CPU (Central Processing Unit) 201, a ROM (Read Only Memory) 202, a RAM (Random Access Memory) 203, a storage unit 204, and I / Fs 205 to 207. The components 201 to 207 are connected by an internal bus 210.

[0039] The CPU 201 controls the entire soil improvement material identification device 1. The ROM 202 stores operation codes for the CPU 201. The RAM 203 is a working area used when the CPU 201 is operating. The storage unit 204 stores various information such as backups of data stored in the ROM 202, databases, and learning target data. As the storage unit 204, for example, a data storage device such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive) is used. For example, the measuring device 3 may have a GPU (Graphics Processing Unit) (not shown).

[0040] The I / F 205 is an interface for transmitting and receiving various information to and from the measuring device 3 and the heating device 4 as necessary via the transmission path 9. The I / F 206 is an interface for transmitting and receiving information to and from the input unit 208. As the input unit 208, for example, a keyboard or a mouse is used, and the user U inputs various information via the input unit 208. The I / F 207 is an interface for transmitting and receiving various information to and from the display unit 209. The display unit 209 displays various information stored in the storage unit 204, evaluation results, etc. A display is used as the display unit 209, and in the case of a touch panel type, for example, it is provided integrally with the input unit 208.

[0041] 3, the control device 2 includes a first communication unit 21, a first storage unit 22, a temperature change rate information acquisition unit 23, and a soil improvement material identification unit 24. The measuring device 3 may further include a reception unit 25 and an output unit 26. Each component of the control device 2 is realized by the CPU 201 using the RAM 203 as a working area to execute a program stored in the ROM 202, the storage unit 204, etc.

[0042] <First communication unit 21> The first communication unit 21 transmits and receives information to, for example, the measuring device 3 and the heating device 4. The first communication unit 21 transmits, for example, information acquired, generated, or stored by each component of the control device 2 to the measuring device 3 and the heating device 4 via the transmission path 9. The first communication unit 21 receives, for example, information acquired, generated, or stored by the measuring device 3 and the heating device 4 via the transmission path 9.

[0043] <First storage section 22> The first storage unit 22 stores, for example, information acquired or generated by each component of the control device 2 in a database stored in the storage unit 204 as necessary. The first storage unit 22 retrieves, for example, various pieces of information stored in the database stored in the storage unit 204 as necessary.

[0044] <Temperature change rate information acquisition unit 23> The temperature change rate information acquisition unit 23 acquires the surface temperature of the cultivation soil S acquired by the measuring device 3 in association with time information, and then receives it from the measuring device 3 via the transmission path 9 and acquires new information. The temperature change rate information acquisition unit 23 acquires multiple change rates of the surface temperature with respect to the square root of the time included in the time information acquired by the measuring device 3, for example.

[0045] In the present invention, a so-called active thermography method is adopted in which a heat load is actively applied to the surface of the cultivation soil S by a heating device 4, and the soil improvement materials are detected by utilizing the difference in temperature change that occurs due to the difference in thermal properties between the soil improvement materials contained in the cultivation soil S and their surroundings.

[0046] <Soil Improvement Materials Identification Division 24> The soil improvement material identifying unit 24 identifies the soil and the soil improvement materials contained in the surface of the cultivation soil S0 based on the ratio of the rate of change of the surface temperature acquired by the temperature change rate information acquiring unit 23 .

[0047] That is, the soil improvement material identification device 1 includes a temperature change rate information acquisition unit 23 that acquires first temperature change rate information indicating the change rate of the surface temperature for a first interval based on, for example, the square root of a first time and the square root of a second time, and second temperature change rate information indicating the change rate of the surface temperature for a second interval based on the square root of a third time later than the first time and the square root of the second time and the fourth time later than the third time, and a soil improvement material identification unit 24 that identifies the soil and soil improvement material contained in the surface of the cultivation soil Sо based on the ratio of the change rate contained in the first temperature change rate information to the change rate contained in the second temperature change rate information. In this case, a highly robust identification can be made based on the ratio obtained by comparing multiple temperature change rates. This can improve the identification accuracy of the soil improvement material in the cultivation soil Sо.

[0048] <Reception Department 25> The receiving unit 25 receives an input from the user U. The receiving unit 25 acquires information related to the operation of the soil improvement material identifying device 1 by a method of receiving an input from the user U via the input unit 208, for example.

[0049] <Output section 26> The output unit 26 outputs information acquired, generated, or stored by each component of the soil improvement material identifying device 1. The output unit 26 presents various information related to the operation of the soil improvement material identifying device 1 to the user U, for example, by a method of outputting to the display unit 209.

[0050] <Measuring equipment 3> The measuring device 3 sequentially acquires the surface temperature of the heated cultivation soil S in chronological order by linking it to time. As the measuring device 3, for example, a known infrared thermography camera is used.

[0051] The measuring device 3 includes, for example, a second communication unit 31, a second storage unit 32, and a surface temperature information acquisition unit 33. The measuring device 3 may be provided with a CPU, ROM, RAM, etc. independent of the control device 2, similar to the control device 2, and each configuration of the measuring device 3 may be realized by executing a program stored in advance by the operation of these. Furthermore, the measuring device 3 may be realized by the CPU 201 of the control device 2 executing a program stored in the ROM 202 or the storage unit 204, etc., using the RAM 203 as a working area. In this case, the measuring device 3 may not be provided with a CPU, ROM, RAM, etc. independent of the control device 2. Furthermore, the measuring device 3 may not be provided with the second communication unit 31 and the second storage unit 32.

[0052] <Second communication unit 31> The second communication unit 31 transmits and receives information to and from, for example, the control device 2. The second communication unit 31 transmits, for example, information acquired, generated, or stored by each component of the measuring device 3 to the control device 2 via the transmission path 9a (transmission path 9). The second communication unit 31 receives, for example, information acquired, generated, or stored by the control device 2 via the transmission path 9a.

[0053] <Second storage unit 32> The second storage unit 32 stores, as necessary, information acquired or generated by each component of the measuring device 3, in a database stored in a storage unit (not shown) of the measuring device 3. The second storage unit 32 retrieves, as necessary, various pieces of information stored in the database stored in the storage unit, for example.

[0054] <Surface temperature information acquisition unit 33> The surface temperature information acquisition unit 33 sequentially acquires the surface temperatures of the cultivation soil S heated by the heating device 4 in chronological order by linking them to the square root of a time based on the start time of heating by the heating device 4. The surface temperature information acquisition unit 33 acquires the surface temperature of the cultivation soil S in a non-contact manner, for example, by a method of detecting infrared rays emitted from the cultivation soil S.

[0055] <Heating equipment 4> The heating device 4 heats the surface of the cultivation soil S with a substantially constant intensity. The heating device 4 may be composed of, for example, a plurality of heating devices 4a, 4b. As the heating device 4, a known halogen lamp heater capable of step heating that applies heat for a long period of time is used, taking into consideration that the active thermography method is applied to the cultivation soil S, which has low thermal diffusivity.

[0056] The heating device 4 includes, for example, a third communication unit 41, a third storage unit 42, and a heating unit 43. The heating device 4 may be provided with a CPU, ROM, RAM, etc. independent of the control device 2, similar to the control device 2, and each configuration of the heating device 4 may be realized by executing a program stored in advance by the operation of these. Furthermore, the heating device 4 may be realized by the CPU 201 of the control device 2 executing a program stored in the ROM 202 or the storage unit 204, etc., using the RAM 203 as a working area. In this case, the heating device 4 may not be provided with a CPU, ROM, RAM, etc. independent of the control device 2. Furthermore, the heating device 4 may not be provided with the third communication unit 41 and the third storage unit 42.

[0057] <Third Communication Department 41> The third communication unit 41 transmits and receives information to, for example, the control device 2. The third communication unit 41 transmits information acquired, generated, or stored by, for example, each component of the heating device 4 to the control device 2 via the transmission path 9b (transmission path 9). The third communication unit 41 receives information acquired, generated, or stored by, for example, the control device 2 via the transmission path 9b.

[0058] <Third storage section 42> The third storage unit 42 stores, as necessary, information acquired or generated by each component of the heating device 4, for example, in a database stored in a storage unit (not shown) of the heating device 4. The heating device 4 retrieves, as necessary, various pieces of information stored in the database stored in the storage unit, for example.

[0059] <Heating section 43> The heating unit 43 heats the surface of the cultivation soil S with a substantially constant intensity.

[0060] <Cultivation soil> The cultivation soil Sо is composed of soil and soil improvement materials. The soil refers to agricultural soil among known soils (soils) existing in nature, and does not include porous materials. The cultivation soil Sо may include one or more soil improvement materials. Here, the soil improvement materials refer to materials that do not include soil and may be present in, for example, the cultivation soil Sо, and specifically include porous materials (including solid organic matter or solid inorganic matter). Examples of organic matter include rice straw, charcoal, bark compost, cow dung compost, rice husk charcoal, and peat. Examples of inorganic matter include vermiculite, perlite, etc. In the description of the present invention, the term "porous material" refers to a porous material other than soil, the term "organic matter" refers to a solid organic material other than soil, and the term "inorganic matter" refers to a solid inorganic material other than soil. The soil improvement material identification device 1 may, for example, identify a porous material contained in the agricultural cultivation soil Sо and then identify the porous material as an organic material. From an agricultural perspective, charcoal, rice straw, and perlite are typical soil improvement materials that are expected to improve physical properties such as permeability and water retention and ensure porosity, which are improvements required at production sites.

[0061] <Transmission Path 9> The transmission path 9 communicatively connects, for example, the control device 2, the measuring device 3, and the heating device 4 to each other. The transmission path 9 may be formed, for example, of a known electric cable for transmitting an electric signal, or a known optical cable for transmitting an optical signal. Furthermore, the transmission path 9 may be realized by known communication technologies such as a wired communication network, a wireless communication network, etc.

[0062] (First embodiment: soil improvement material identification method) Next, as a soil improvement material identification method in this embodiment, an example of the operation of the soil improvement material identification device 1 will be described with reference to the drawings. The operation of the soil improvement material identification device 1 is executed, for example, via a soil improvement material identification program installed in the soil improvement material identification device 1.

[0063] The operation of the soil improvement material identifying device 1 includes, for example, a heating step S11, a surface temperature information acquiring step S12, a temperature change rate information acquiring step S13, and a soil improvement material identifying step S14, as shown in Fig. 4. Note that the operation of the soil improvement material identifying device 1 may perform each step multiple times.

[0064] First, a description will be given of various types of information associated with the operation of the soil improvement material identifying device 1 in this embodiment. The various types of information handled by the soil improvement material identifying device 1 include, for example, setting information D1, measurement information D2, temperature change rate information D3, and output information D4, as shown in Fig. 5.

[0065] <Setting information D1> The setting information D1 is information indicating the operating conditions of the measuring device 3 and the heating device 4. The setting information D1 is stored in advance, for example, in the soil improvement material identifying device 1. The setting information D1 includes, for example, measurement condition information D1a and heating condition information D1b.

[0066] <Measurement condition information D1a> The measurement condition information D1a is information indicating the measurement conditions of the measuring device 3. The measurement condition information D1a may include, for example, the measurement range of the measuring device 3 on the surface of the cultivation soil S, the measurement interval, the communication interval of the measurement result, etc. The measurement condition information D1a is stored in advance in, for example, a storage unit (not shown) of the measuring device 3.

[0067] <Heating condition information D1b> The heating condition information D1b is information indicating the heating conditions of the heating device 4. The heating condition information D1b may include, for example, the heating intensity and heating time of the heating device 4 for the surface of the cultivation soil S. The heating condition information D1b is stored in advance, for example, in a storage unit (not shown) of the heating device 4.

[0068] <Measurement information D2> The measurement information D2 is information about the surface temperature of the cultivation soil S obtained by the measuring device 3. The measurement information D2 is stored, for example, in the control device 2 capable of transmitting and receiving information to and from the measuring device 3. The measurement information D2 includes, for example, surface temperature information D2a and time information D2b.

[0069] <Surface temperature information D2a> The surface temperature information D2a is information indicating the surface temperature of the cultivation soil So obtained by the measuring device 3. The surface temperature information D2a may be, for example, information that uniquely indicates the surface temperature, or information that indicates the surface temperature by a range.

[0070] <Time information D2b> The time information D2b is information indicating the square root of the time associated with the surface temperature information D2a. Here, the time is the elapsed time from the heating start time of the heating device 4. The time information D2b may indicate the square root of the elapsed operation time of the heating device 4, with the heating start time of the heating device 4 being set as zero.

[0071] The time information D2b may be, for example, information indicating the square root of the time when the measuring device 3 acquired the surface temperature information D2a, or may be information indicating the square root of the time when the measuring device 3 detected the surface temperature of the cultivation soil So.

[0072] <Temperature change rate information D3> The temperature change rate information D3 is information indicating the rate of change of the surface temperature of the cultivation soil S with respect to the square root of the time. For example, the temperature change rate information D3 indicates the rate of change of the surface temperature included in the surface temperature information D2a linked to the time information D2b for a section specified with one of the square roots of the times that is earlier in the chronological order as the start point and the other that is later as the end point, for the square roots of the two times included in the time information D2b. The temperature change rate information D3 includes, for example, first temperature change rate information D3a, second temperature change rate information D3b, and ratio information D3c.

[0073] <First temperature change rate information D3a> The first temperature change rate information D3a is information indicating the change rate of the surface temperature of the cultivation soil S for a first interval ((√t2)-(√t1)) based on the square root (√t1) of the first time t1 included in the time information D2b and the square root (√t2) of the second time t2 that is later than the first time t1. The first temperature change rate information D3a can be calculated, for example, as a value obtained by dividing the amount of change in the surface temperature of the cultivation soil S in the first interval by the time corresponding to the second interval.

[0074] <Second temperature change rate information D3b> The second temperature change rate information D31 is information that indicates the rate of change of the surface temperature of the cultivation soil S for a second interval ((√t4)-(√t3)) based on the square root (√t3) of a third time t3 that is included in the time information D2b and that is later than the first time t1 and the square root (√t4) of a fourth time t4 that is later than the second time t2 and the third time t3. The second temperature change rate information D3b may be calculated, for example, as a value obtained by dividing the amount of change in the surface temperature of the cultivation soil S in the second interval by the time corresponding to the second interval. The rate of change included in the second temperature change rate information D3b may be the same as the rate of change included in the first temperature change rate information D3a.

[0075] The time corresponding to the second interval does not overlap with the time corresponding to the first interval, for example. Specifically, the third time t3, which is the starting point of the second interval, is preferably after the surface temperature of the cultivation soil S has risen sufficiently from the first time t1, which is the starting point of the first interval, and for example, a combination of the first time t1 and the third time t3 at which the surface temperature of the cultivation soil S linked to the square root of the third time t3 (√t3) is 10°C or more higher than the surface temperature of the cultivation soil S linked to the square root of the first time t1 (√t1) is preferable.

[0076] <Ratio Information D3c> The ratio information D3c is information indicating the ratio between the rate of change included in the first temperature change rate information D3a and the rate of change included in the second temperature change rate information D3b. The ratio information D3c may be, for example, a ratio calculated by dividing the rate of change included in the first temperature change rate information D3a by the rate of change included in the second temperature change rate information D3b, or may be a ratio calculated by dividing the rate of change included in the second temperature change rate information D3b by the rate of change included in the first temperature change rate information D3a.

[0077] <Output information D4> The output information D4 is information output by the soil improvement material identifying device 1 based on the first temperature change rate information D3a and the second temperature change rate information D3b. The output information D4 includes, for example, soil improvement material identifying information D4a.

[0078] <Soil improvement material identification information D4a> The soil improvement material identification information D4a is information indicating the ratio between the change rate contained in the first temperature change rate information D3a and the change rate contained in the second temperature change rate information D3b, or the presence or absence of a soil improvement material identified based on the ratio.

[0079] Next, the operation of the soil improvement material identification device 1 in this embodiment will be described in detail.

[0080] <Advance preparation> Before operating the soil improvement material identifying device 1, the user U confirms that the setting information D1 is stored in the soil improvement material identifying device 1.

[0081] <Heating process S11> In the heating step S11, the heating unit 43 heats the surface of the cultivation soil S with a substantially constant intensity.

[0082] As shown in FIG. 6(a), for example, the heating unit 43 heats the surface of the cultivation soil So at a substantially constant intensity in accordance with the conditions for heating at a substantially constant intensity I contained in the preset heating condition information D1b.

[0083] <Surface temperature information acquisition step S12> In the surface temperature information acquisition step S12, the surface temperature information acquisition unit 33 sequentially acquires surface temperature information D2a indicating the surface temperature of the cultivation soil S0 heated in the heating step S11 in chronological order by linking the surface temperature information D2a to time information D2b.

[0084] The surface temperature information acquisition unit 33, for example as shown in Figure 6 (b), links and sequentially acquires a combination of surface temperature information D2a indicating the surface temperature T of the cultivation soil S and time information D2b indicating time t in chronological order in accordance with conditions indicating the measurement interval of the measuring device 3 contained in preset measurement condition information D1a. The surface temperature information acquisition unit 33 may, for example, link a combination (T1, √t1) of surface temperature information D21a indicating surface temperature T1 and time information D22b indicating the square root of time t1, a combination (T2, √t2) of surface temperature information D22a indicating surface temperature T2 and time information D22b indicating the square root of time t2, a combination (T3, √t3) of surface temperature information D23a indicating surface temperature T3 and time information D23b indicating the square root of time t3, and a combination (T4, √t4) of surface temperature information D24a indicating surface temperature T4 and time information D24b indicating the square root of time t4, and sequentially acquire the square root of the first time √t1, the square root of the second time √t2, the square root of the third time √t3, and the square root of the fourth time √t4 in chronological order.

[0085] <Temperature change rate information acquisition step S13> In the temperature change rate information acquisition process S13, the temperature change rate information acquisition unit 23 acquires first temperature change rate information D3a indicating the rate of change of the surface temperature for the first interval based on the time information D2b acquired by the surface temperature information acquisition process S12, and second temperature change rate information D3b indicating the rate of change of the surface temperature for the second interval.

[0086] As shown in FIG. 6(c), for example, the temperature change rate information acquisition unit 23 converts the combination of surface temperature information D21a and time information D21b (T1, √t1) and the combination of surface temperature information D22a and time information D22b (T2, √t2) into combinations of surface temperature and the square root of time, and then calculates the change rate ΔT1 of the surface temperature for the first interval according to the following equation (6).

[0087]

number

[0088] Thereafter, the temperature change rate information acquisition unit 23 acquires the change rate ΔT1 as first temperature change rate information D3a.

[0089] Similarly, the temperature change rate information acquisition unit 23 converts, for example, a combination (T3, √t3) of surface temperature information D23a and time information D23b and a combination (T4, √t4) of surface temperature information D24a and time information D24b into a combination of the surface temperature and the square root of the time, and calculates the change rate ΔT2 of the surface temperature for the second interval according to the following formula (7). Note that the time (√t4-√t3) corresponding to the second interval and the time (√t2-√t1) corresponding to the first interval indicate, for example, the same time.

[0090]

number

[0091] Thereafter, the temperature change rate information acquisition unit 23 acquires the change rate ΔT2 as second temperature change rate information D3b.

[0092] Thereafter, the temperature change rate information acquiring unit 23 calculates the ratio C of the change rate ΔT2 to the change rate ΔT1 according to the following formula (8).

[0093]

number

[0094] Thereafter, the temperature change rate information acquisition unit 23 acquires the ratio C as ratio information D3c.

[0095] <Soil improvement material identification process S14> In the soil improvement material identification process S14, the soil improvement material identification unit 24 identifies the soil and soil improvement materials contained in the surface of the cultivation soil So based on the ratio C contained in the ratio information D3c acquired in the temperature change rate information acquisition process S13.

[0096] The soil improvement material identification unit 24 identifies whether the object is soil or a soil improvement material, for example, by comparing the ratio C with a preset reference value. When the ratio C is equal to or greater than a preset reference value (e.g., a value taking into account an error with 1 as the reference), that is, when the slope of the surface temperature versus the square root of time can be considered to have remained almost unchanged over time, the soil improvement material identification unit 24 identifies the object as soil (earth). When the ratio C is lower than the above-mentioned preset reference value, that is, when the slope of the surface temperature versus the square root of time can be considered to have decreased over time, the soil improvement material identification unit 24 identifies the object as a soil improvement material made of a porous material.

[0097] That is, the operating method of the soil improvement material identifying device 1 includes a temperature change rate information acquiring step S13 for acquiring first temperature change rate information D3a indicating the rate of change ΔT1 of surface temperature for the first interval and second temperature change rate information D3b indicating the rate of change ΔT2 of surface temperature for the second interval, and a soil improvement material identifying step D14 for identifying the soil and soil improvement materials contained in the surface of the cultivation soil Sо based on the ratio C of the first temperature change rate information D3a and the second temperature change rate information D3b. In this case, it is possible to perform highly robust identification by comparing multiple temperature change rates. This makes it possible to improve the accuracy of identifying the soil improvement materials in the cultivation soil Sо.

[0098] In the soil improvement material identifying step S14, the soil improvement material identifying unit 24 may output soil improvement material identifying information D4a indicating the attributes of the soil improvement material. The soil improvement material identifying unit 24 may output soil identifying information D41a when the measurement target is identified as soil based on the ratio C, and may output porous material identifying information D42a when the measurement target is identified as a porous material based on the ratio C.

[0099] After performing each of the above-mentioned steps, the operation of the structure inspection system 100 in this embodiment ends. Note that, in the structure inspection system 100, for example, each of the above-mentioned steps may be repeatedly performed.

[0100] The soil improvement material identifying device 1 may start or end each process from the time when an input from the user U is received via the receiving unit 25.

[0101] In addition, the soil improvement material identification device 1 may present the information identified in the soil improvement material identification process S14 or the output soil improvement material identification information D4a to the user U via the display unit 209 or the like via the output unit 26.

[0102] (First embodiment: modified example of operation of the soil improvement material identification device 1) <Measurement information D2> The measurement information D2 further includes a surface temperature image D2c, as shown in FIG. 7(a), for example.

[0103] <Surface temperature image D2c> The surface temperature image D2c is information showing the surface temperature of the cultivation soil S0 as a two-dimensional image acquired by the measuring device 3. The surface temperature image D2c is acquired in association with time information D2b, for example, as shown in FIG. 7(b).

[0104] Next, the operation of the soil improvement material identification device 1 in this embodiment will be described in detail.

[0105] <Surface temperature information acquisition step S12> In the surface temperature information acquisition step S12, the surface temperature information acquisition unit 33 sequentially acquires surface temperature images D2c, which show the surface temperature of the cultivation soil S heated in the heating step S11 as two-dimensional images, in chronological order by linking them to the time information D2b.

[0106] 7(b), the soil improvement material identification unit 24 sequentially acquires combinations (TI, √t) in chronological order, each of which is a surface temperature image D2c showing a planar surface temperature TI including a plurality of surface temperatures T of the cultivation soil S0 as a two-dimensional image and time information D2b showing the square root of time t, in accordance with conditions indicating the measurement interval of the measurement device 3, which are included in the preset measurement condition information D1a. Here, the planar surface temperature TI may include one or more surface temperatures T.

[0107] The surface temperature information acquisition unit 33 may, for example, link a combination of a surface temperature image D21c indicating a surface surface temperature TI1 and time information D21b indicating the square root of time t1 (TI1, √t1), a combination of surface temperature information D22a indicating a surface surface temperature TI2 and time information D22b indicating the square root of time t2 (TI2, √t2), a combination of surface temperature information D23a indicating a surface surface temperature TI3 and time information D23b indicating the square root of time t3 (TI3, √t3), and a combination of surface temperature information D24a indicating a surface surface temperature TI4 and time information D24b indicating the square root of time t4 (TI4, √t4), and sequentially acquire the square root of the first time √t1, the square root of the second time √t2, the square root of the third time √t3, and the square root of the fourth time √t4 in chronological order.

[0108] <Temperature change rate information acquisition step S13> In the temperature change rate information acquisition step S13, the temperature change rate information acquisition unit 23 acquires first temperature change rate information D3a and second temperature change rate information D3b for each of a plurality of image blocks generated by dividing the surface temperature image D2c. As described above, the temperature change rate information acquisition unit 23 acquires first temperature change rate information D3a indicating the change rate ΔT1 for one or more image blocks included in the planar surface temperature TI for the first interval based on the time information D2b acquired in the surface temperature information acquisition step S12, and second temperature change rate information D3b indicating the change rate ΔT2 of the surface temperature for the second interval. After that, the temperature change rate information acquisition unit 23 calculates the ratio C of the change rate ΔT2 to the change rate ΔT1 for each image block, and acquires the ratio C as ratio information D3c.

[0109] Specifically, the temperature change rate information acquisition unit 23 calculates the ratio C for each image block, with one pixel being one image block, as shown in Fig. 7(c), for example, and acquires the ratio C as ratio information D3c. Note that the temperature change rate information acquisition unit 23 may also calculate the ratio C for each image block, with multiple pixels (e.g., four pixels) being one image block, as shown in Fig. 8, for example, and acquire the ratio C as ratio information D3c.

[0110] <Soil improvement material identification process S14> In the soil improvement material identification process S14, the soil improvement material identification unit 24 identifies the ratio of the number of image blocks of the soil improvement material identified for each image block to the number of image blocks corresponding to the cultivation soil So, based on the ratio C acquired in the temperature change rate information acquisition process S13.

[0111] The soil improvement material identification unit 24 outputs soil identification information D41a and porous material identification information D42a for each image block based on the ratio C contained in the ratio information D3c acquired by the temperature change rate information acquisition process S13, as shown in Figure 7(c), for example, and then outputs the ratio "XX%" of the soil identification information D41a to the number of image blocks of the soil improvement material identification information D4a and the ratio "YY%" of the porous material identification information D42a to the number of image blocks of the soil improvement material identification information D4a.

[0112] That is, the temperature change rate information acquisition unit 23 acquires the first temperature change rate information D3a and the second temperature change rate information D3b for each of the multiple image blocks, and the soil improvement material identification unit 24 identifies the ratio of the number of image blocks of the soil improvement materials identified for each image block based on the first temperature change rate information D3a and the second temperature change rate information D3b to the number of image blocks corresponding to the cultivation soil S. In this case, a highly robust identification can be made of the proportion of the soil improvement materials in the image based on the ratio C obtained by comparing multiple temperature change rates. This can improve the convenience of identifying the soil improvement materials in the cultivation soil S.

[0113] The soil improvement material identifying unit 24 may output the soil identification information D41a and the porous material identifying information D42a for each image block based on the ratio C included in the ratio information D3c acquired in the temperature change rate information acquisition step S13, and then output the position of the soil improvement material identifying unit 24 as relative coordinates in the local coordinate system (X, Y) in the surface temperature image D2c. In this case, the soil improvement material identifying unit 24 outputs, for example, the relative coordinates "..., (X2, Y1-Y5), (X3, Y1-Y2),..." of the soil identification information D41a and the relative coordinates "..., (X3, Y3-Y4), (X4, Y1-Y2),..." of the porous material identifying information D42a.

[0114] That is, the temperature change rate information acquisition unit 23 acquires the first temperature change rate information D3a and the second temperature change rate information D3b for each of the multiple image blocks, and the soil improvement material identification unit 24 identifies the relative position in the surface temperature image D2c for the image block of the soil improvement material identified for each image block based on the first temperature change rate information D3a and the second temperature change rate information D3b. In this case, it is possible to perform highly robust identification of the relative position of the soil improvement material in the image based on the ratio C obtained by comparing multiple temperature change rates. This makes it possible to improve the convenience of identifying the soil improvement material in the cultivation soil Sо.

[0115] In addition, the soil improvement material identification unit 24 may acquire soil improvement material identification information D4a for each pixel, for example as shown in Figure 8, and then treat multiple pixels (for example, four pixels) as one image block, and identify the soil identification information D41a or the porous material identification information D42a, whichever accounts for the majority of the number of pixels, as the soil improvement material identification information D4a in that image block, or when the number of pixels of the porous material identification information D42a is 1 or more, the porous material identification information D42a may be identified as the soil improvement material identification information D4a in that image block.

[0116] According to this embodiment, the present invention includes a temperature change rate information acquisition unit 23 that acquires first temperature change rate information D3a indicating the rate of change of the surface temperature for the first section and second temperature change rate information D3b indicating the rate of change of the surface temperature for the second section, and a soil improvement material identification unit 24 that identifies the soil and soil improvement materials contained in the surface of the cultivation soil S on the basis of a ratio C between the rate of change contained in the first temperature change rate information D3a and the rate of change contained in the second temperature change rate information D3b. This allows for highly robust identification based on the ratio C obtained by comparing multiple temperature change rates. This allows for improved accuracy in identifying the soil improvement materials in the cultivation soil S.

[0117] Further, according to this embodiment, the temperature change rate information acquisition unit 23 acquires the first temperature change rate information D3a and the second temperature change rate information D3b for each of the multiple image blocks, and the soil improvement material identification unit 24 identifies the ratio of the number of image blocks of the soil improvement material identified for each image block based on the first temperature change rate information D3a and the second temperature change rate information D3b to the number of image blocks corresponding to the cultivation soil S. Therefore, it is possible to perform highly robust identification of the proportion of the soil improvement material in the image based on the ratio C obtained by comparing multiple temperature change rates. This improves the convenience of identifying the soil improvement material in the cultivation soil S.

[0118] Further, according to this embodiment, the temperature change rate information acquisition unit 23 acquires the first temperature change rate information D3a and the second temperature change rate information D3b for each of the multiple image blocks, and the soil improvement material identification unit 24 identifies the relative position of the soil improvement material identified for each image block based on the first temperature change rate information D3a and the second temperature change rate information D3b with respect to the surface temperature image D2c. Therefore, it is possible to perform highly robust identification of the relative position of the soil improvement material in the image based on the ratio C obtained by comparing multiple temperature change rates. This makes it possible to improve the convenience of identifying the soil improvement material in the cultivation soil S.

[0119] Further, according to this embodiment, there are provided a temperature change rate information acquisition step S13 for acquiring first temperature change rate information D3a indicating the rate of change of the surface temperature for the first section and second temperature change rate information D3b indicating the rate of change of the surface temperature for the second section, and a soil improvement material identification step S14 for identifying the soil and the soil improvement material contained in the surface of the cultivation soil S on the basis of a ratio C between the first temperature change rate information D3a and the second temperature change rate information D3b. Therefore, a highly robust identification can be made on the basis of the ratio C obtained by comparing a plurality of temperature change rates. This can improve the accuracy of identification of the soil improvement material in the cultivation soil S.

[0120] (Second embodiment: soil improvement material identification method) An example of the operation of the soil improvement material identification device 1 will be described as a soil improvement material identification method in this embodiment with reference to the drawings. This embodiment differs from the first embodiment in that the soil improvement material identification device 1 identifies the soil and soil improvement materials contained in the cultivation soil S0 after referring to the database D6. Note that a description of the same configuration as that described above will be omitted.

[0121] First, a description will be given of various types of information associated with the operation of the soil improvement material identifying device 1 in this embodiment. The various types of information handled by the soil improvement material identifying device 1 include a database D6, as shown in Fig. 9(a), for example.

[0122] <Database D6> The database D6 is a collection of data stored in advance in the soil improvement material identification device 1. The database D6 is stored in advance in the storage unit 204 of the control device 2, for example.

[0123] The database D6 stores, for example as shown in Figure 9(a), a ratio information table T61 that stores pre-acquired reference ratio information D61 corresponding to the ratio information D3c, and an identification information table T62 that stores pre-acquired reference soil improvement material identification information D62 corresponding to the soil improvement material identification information D4a.

[0124] In the database D6, as shown in FIG. 9(b), each piece of information in the reference ratio information D61 and each piece of information in the reference soil improvement material identification information D62 are stored in association with each other. For example, the database D6 may store information indicating the ratio C included in the reference ratio information D61 and information indicating the soil improvement material name and soil improvement material porosity (unit:%) included in the reference soil improvement material identification information D62 in association with each other. The reference ratio information D61 may include, for example, a ratio C that can be identified for the soil improvement material included in the reference soil improvement material identification information D62, or may include a ratio that can be estimated when the identification of the soil improvement material is unclear (for example, a threshold value wider than the ratio C). In this case, the soil improvement material identification device 1 may function as a soil improvement material estimation device that estimates the soil improvement material based on the soil improvement material identification information D4a corresponding to the ratio information D3c.

[0125] That is, the soil improvement material identification device 1 refers to a database D6 in which reference ratio information D61 corresponding to ratio information D3c indicating the ratio C between the first temperature change rate information D3a and the second temperature change rate information D3b and reference soil improvement material identification information D62 corresponding to the soil improvement material identification information D4a are linked in advance, and estimates or identifies the soil improvement material based on the soil improvement material identification information D4a corresponding to the ratio information D3c. Therefore, it is possible to estimate or identify the details of the soil improvement material with high robustness based on the ratio C obtained by comparing multiple temperature change rates. This makes it possible to improve the convenience of estimating or identifying the soil improvement material in the cultivation soil S.

[0126] The reference ratio information D61 may be linked to the soil improvement material name "aa" in the reference soil improvement material identification information D62 for the ratio "a", and to the soil improvement material name "bb" in the reference soil improvement material identification information D62 for the ratio "b". In addition, the reference ratio information D61 may have a preset identification value such as the ratio "a=a1" or "b=b1", or may have a preset threshold value for identification by two values ​​such as the ratio "a=a1-a2" or "b=b1-b2". In addition, the reference ratio information D61 may be linked to the soil improvement material name "porous material" in the reference soil improvement material identification information D62 for each threshold value of the ratio C. In this case, the details of the soil improvement material (for example, whether it is a porous material or not) can be estimated or identified according to the value of the ratio C. This can improve the convenience of estimating or identifying the soil improvement material in the cultivation soil S.

[0127] In the reference ratio information D61, the soil improvement material name "ca" and the soil improvement material porosity "cb" in the reference soil improvement material identification information D62 may be linked for the ratio "c", and the soil improvement material name "da" and the soil improvement material porosity "db" in the reference soil improvement material identification information D62 may be linked for the ratio "d". Here, the soil improvement material names "aa", "ba", "ca", and "da" may indicate the same content as each other, or may indicate different content. Also, the soil improvement material porosities "cb" and "db" may indicate the same content as each other, or may indicate different content.

[0128] <Ratio information table T61> The ratio information table T61 stores reference ratio information D61, for example, as shown in FIG. 9(a).

[0129] <Reference ratio information D61> The reference ratio information D61 is stored in advance in, for example, a ratio information table T61. The reference ratio information D61 is, for example, information corresponding to the ratio information D3c, and may include information similar to the ratio information D3c.

[0130] For example, when incorresponding ratio information D3c is input or stored in any component of the soil improvement material identification device 1, the reference ratio information D61 may be newly stored in the control device 2 via the first memory unit 22, etc., corresponding to the ratio information D3c.

[0131] <Identification information table T62> The identification information table T62 stores, for example, reference soil improvement material identification information D62.

[0132] <Reference soil improvement material identification information D62> The reference soil improvement material identification information D62 is stored in advance in, for example, an identification information table T62. The reference soil improvement material identification information D62 is, for example, information corresponding to the soil improvement material identification information D4a, and may include information similar to the soil improvement material identification information D4a.

[0133] For example, when non-corresponding soil improvement material identification information D4a is input or stored in any component of the soil improvement material identification device 1, the reference soil improvement material identification information D62 may be newly stored in the control device 2 via the first memory unit 22, etc., corresponding to the soil improvement material identification information D4a.

[0134] Next, the operation of the soil improvement material identification device 1 in this embodiment will be described in detail.

[0135] <Advance preparation> Before operating the soil improvement material identifying device 1, the user U confirms that the database D6 is stored in the soil improvement material identifying device 1.

[0136] <Soil improvement material identification process S14> In the soil improvement material identification step S14, the soil improvement material identification unit 24 refers to a database D6 in which reference ratio information D61 corresponding to the ratio information D3c and reference soil improvement material identification information D62 corresponding to the soil improvement material identification information D4a are linked in advance, and estimates or identifies the soil improvement material based on the soil improvement material identification information D4a corresponding to the ratio information D3c. In this case, a robust estimation or identification of the details of the soil improvement material can be performed by comparing multiple temperature change rates. This improves the convenience of estimating or identifying the soil improvement material in the cultivation soil S.

[0137] According to this embodiment, the soil improvement material identification unit 24 refers to a database D6 in which reference ratio information D61 corresponding to ratio information D3c indicating the ratio C between the first temperature change rate information D3a and the second temperature change rate information D3b and reference soil improvement material identification information D62 corresponding to the soil improvement material identification information D4a are linked in advance, and estimates the soil improvement material based on the soil improvement material identification information D4a corresponding to the ratio information D3c. Therefore, it is possible to make a highly robust estimation of the details of the soil improvement material based on the ratio C obtained by comparing multiple temperature change rates. This improves the convenience of estimating the soil improvement material in the cultivation soil S. EXAMPLES

[0138] Hereinafter, experimental results regarding the effects of the soil improvement material identification device 1 when the above-described embodiment is used will be described.

[0139] In this experiment, for the samples of soil improvement materials and soil, the temperature change rate information D3 calculated based on the actual measured values ​​of measurement information D2 obtained by measuring equipment 3 while heated by heating equipment 4 was compared to confirm the difference in ratio C.

[0140] <Experimental conditions> The soil improvement materials used for the samples were charcoal, rice straw, and perlite. The charcoal used was "Coniferous and broadleaf mixed charcoal (carbonized in an open hearth, particle size 3mm-5mm)" manufactured by Takatsuki Biochar Energy Institute. The rice straw used was rice (Hinohikari) cultivated in a paddy field in Hirakata City, Osaka Prefecture, by a known method. The perlite used was "KING PEARL (L) 100L" manufactured by Mitsui Mining & Smelting Co., Ltd. The soil samples used were river sand for charcoal to compare with charcoal, and soil (plateau development soil) collected from the Setsunan University Farm (Hirakata City, Osaka Prefecture) for rice straw to compare with charcoal and perlite to compare with perlite.

[0141] As the measuring device 3, a thermograph (R450, measuring wavelength 8-14 μm, pixel number 480 × 360) manufactured by Nippon Avionics was used. As for the photographing conditions, thermal images of the soil improvement material and the soil during heating were recorded at 1 second intervals from a position about 700 mm above the soil improvement material and the soil, and were converted into time-series two-dimensional temperature data (surface temperature image D2c). In addition, for the converted two-dimensional temperature data, the temperature change with respect to the square root of time was calculated at all measuring points (image blocks) in the two-dimensional temperature data using a control device 2 in which numerical analysis software (MATLAB (registered trademark)) was stored in advance. The measuring area was 255 mm × 230 mm.

[0142] As heating device 4, two halogen lamp heaters (1kW, color temperature 3050K, reflective mirror type) manufactured by Fintec Co., Ltd. were used. In order to keep the irradiation intensity constant, the lamp was turned on and irradiation of the sample was started after confirming that the irradiation intensity was stable. At this time, the heating by the lamp was prevented by covering the heating target with a heat-shielding cover until the irradiation intensity was stable, and after the irradiation intensity was stabilized, the heat-shielding cover was removed and step heating of the sample was performed.

[0143] As a method of deriving ratio C, in addition to using the raw data of the measurement value by measuring device 3, a total of three types of data were confirmed: using an approximation curve related to the raw data and using the differential coefficient related to the approximation curve in order to smooth out error fluctuations.

[0144] The approximation curve was approximated by a cubic function, and the rate of change in surface temperature for the second section, ΔT2, was derived based on the cubic function. Note that the rate of change in surface temperature for the first section, ΔT1, was derived using raw data, since smoothing was not required near the intercept of the approximation curve (the surface temperature of the sample corresponding to the time when heating started).

[0145] Regarding the differential coefficient, based on the differential equation (quadratic function) of the approximation curve, the average value of the differential coefficient at the start and end points of the second section was taken as the rate of change ΔT2 of the surface temperature for the second section. Note that, regarding the rate of change ΔT1 of the surface temperature for the first section, it was derived using the raw data, since there was no need for smoothing near the intercept of the approximation curve.

[0146] <Experimental results: Charcoal, soil for charcoal> Charcoal data D91 showing actual measurements taken by measuring device 3 when charcoal was used is shown in Fig. 10. The charcoal data D91 includes four types of charcoal data D91a, ​​D91b, D91c, and D91d showing experimental results for four samples of charcoal. Table 1 shows the surface temperatures T (T1, T2, T3, T4) of the samples when the first time t1 = 1, the second time t2 = 16, the third time t3 = 64, and the fourth time t4 = 121 for each of the four types of charcoal data D91a, ​​D91b, D91c, and D91d, the rate of change ΔT1 of the surface temperature for the first section, the rate of change ΔT2 of the surface temperature for the second section, and the ratio C.

[0147] [Table 1]

[0148] According to Table 1, the ratios C of the four types of charcoal data D91a, ​​D91b, D91c, and D91d were 0.513, 0.516, 0.439, and 0.490, respectively. The average value of the ratios C was 0.489, and the standard deviation was 0.031.

[0149] FIG 11 shows the results of converting the four types of charcoal data D91a, ​​D91b, D91c, and D91d shown in FIG 10 into cubic function approximation curves. In detail, in FIG 10, the solid line shows the approximation curve for charcoal data D91a, ​​the dashed line shows the approximation curve for charcoal data D91b, the dashed line shows the approximation curve for charcoal data D91c, and the dashed line shows the approximation curve for charcoal data D91d. 2 indicates the correlation coefficient of the approximation curve. Table 2 shows the surface temperature T (T1, T2, T3, T4) of the sample when the first time t1 = 1, the second time t2 = 16, the third time t3 = 64, and the fourth time t4 = 121 for each of the approximation curves of the four types of charcoal data D91a, ​​D91b, D91c, and D91d, the rate of change ΔT1 of the surface temperature for the first interval, the rate of change ΔT2 of the surface temperature for the second interval, and the ratio C. Each data shown in Table 2 corresponds to a value calculated by converting the value of each raw data shown in Table 1 into the approximation curve of a cubic function.

[0150] [Table 2]

[0151] According to Table 2, the ratios C of the approximation curves of the four types of charcoal data D91a, ​​D91b, D91c, and D91d were 0.560, 0.539, 0.563, and 0.491, respectively. The average value of the ratios C was 0.538, and the standard deviation was 0.029. In other words, compared to the ratios C based on the actual measured values ​​shown in Table 1, the standard deviation can be reduced, and a more reproducible ratio C can be obtained.

[0152] Moreover, after calculating differential equations for the approximation curves of the four types of charcoal data D91a, ​​D91b, D91c, and D91d shown in Fig. 11, the average value of the differential coefficient (the slope of the tangent to the approximation curve) at the first time t1 = 1 and the differential coefficient at the second time t2 = 16 is taken as the rate of change ΔT1 of the surface temperature for the first interval, and the average value of the differential coefficient at the third time t3 = 64 and the differential coefficient at the fourth time t4 = 121 is taken as the rate of change ΔT2 of the surface temperature for the second interval. Table 3 shows the ratio C. The data shown in Table 3 correspond to values ​​calculated by converting the approximation curves of the data shown in Table 2 into differential coefficients.

[0153] [Table 3]

[0154] According to Table 3, the ratios C based on the average values ​​of the differential coefficients for the approximation curves of the four types of charcoal data D91a, ​​D91b, D91c, and D91d were 0.558, 0.529, 0.561, and 0.485, respectively. The average value of the ratios C was 0.533, and the standard deviation was 0.031. In other words, compared to the ratios C based on the actual measured values ​​shown in Table 1, the standard deviation is not reduced, but it is possible to obtain a similar standard deviation, and a more reproducible ratio C can be obtained based on a formula with a relatively low processing load.

[0155] 12 shows charcoal soil data D92, which shows actual measurements taken by the measuring device 3 when soil for charcoal is used. The charcoal soil data D92 includes five types of charcoal soil data D92a, D92b, D92c, D92d, and D92e, which show experimental results for five samples of soil for charcoal. Table 4 shows the surface temperatures T (T1, T2, T3, and T4) of the samples when the first time t1 is 1, the second time t2 is 16, the third time t3 is 64, and the fourth time t4 is 121, the rate of change ΔT1 of the surface temperature for the first interval, the rate of change ΔT2 of the surface temperature for the second interval, and the ratio C for each of the five types of charcoal soil data D92a, D92b, D92c, D92d, and D92e.

[0156]

Table 4

[0157] According to Table 4, the ratios C of the five types of soil data D92a, D92b, D92c, D92d, and D92e for charcoal were 1.186, 1.270, 1.135, 1.242, and 1.009, respectively. Also, the average value of the ratio C at this time was 1.168, and the standard deviation was 0.092.

[0158] That is, when the soil improvement material identification unit 24 uses, for example, numerical values such as a preset constant "1 (where 0 < C ≤ 1)", a threshold value "1 or more", and a threshold value "0.8 to 1.2" as reference values, that is, when the slope of the surface temperature with respect to the square root of time can be regarded as having changed little over time, the measurement object can be identified as soil (soil for charcoal). Also, when the ratio C is, for example, a value lower than the above-mentioned preset reference value, that is, when the slope of the surface temperature with respect to the square root of time can be regarded as decreasing over time, the measurement object can be identified as charcoal, which is a porous material. Therefore, the soil improvement material identification device 1 can identify soil and charcoal, which is a soil improvement material of a porous material, by a highly robust identification method based on the ratio C obtained by comparing a plurality of temperature change rates ΔT1 and ΔT2.

[0159] Here, consider the change over time of the surface temperature of the samples shown in FIGS. 10 to 12. According to FIG. 12, it can be seen that for the soil for charcoal, the temperature change is linear, and the temperature rises in proportion to the square root of time. On the other hand, according to FIGS. 10 to 11, it can be seen that for charcoal, the temperature change is not linear, and the rate of temperature change gradually becomes gentler as time passes. Considering that the heat flux q s is constant, it is considered that the thermal diffusivity e in Equation (5) changes, that is, the thermophysical properties of charcoal change.

[0160] According to "Tatsuya Kobari, Junnosuke Okajima, Atsuki Komiya, Shigenao Maruyama, "Evaluation of Radiative Heat Transfer in High-Temperature Porous Insulation Materials by Using Diffusion Approximation", Netsu Bussei 28(4) (2014) 179-184.," it is known that the effective thermal conductivity of porous materials increases with increasing temperature due to the contribution of radiation transport. In addition, charcoal is a porous material with a porous structure, and its effective thermal conductivity increases as the temperature increases. As a result, it is thought that charcoal showed a change in which the temperature increase becomes more gradual over time. For the above reasons, it can be said that the soil improvement material identification device 1 can identify soil and charcoal, which is a soil improvement material made of a porous material, by a highly robust identification method based on the ratio C obtained by comparing multiple temperature change rates ΔT1 and ΔT2. Furthermore, since similar trends are observed for rice straw, soil for rice straw, perlite, and soil for perlite, which will be described later and are shown in Figures 13 to 18, it is believed that the same reason also applies to these porous materials and soil for porous materials.

[0161] In this embodiment, an approximation curve of a cubic function is used, but this is not limited to this and other approximation methods or smoothing methods may be used. For example, an approximation curve obtained by a moving average method for actual measured values ​​may be used.

[0162] <Experimental results: rice straw, soil for rice straw> Next, rice straw data D93 showing actual measurements by the measuring device 3 when rice straw was used is shown in FIG. 13. The rice straw data D93 includes four types of rice straw data D93a, D93b, D93c, and D93d showing experimental results for four samples of charcoal. In addition, for each of the four types of rice straw data D93a, D93b, D93c, and D93d, Table 5 shows the surface temperature T (T1, T2, T3, T4) of the sample when the first time t1 = 1, the second time t2 = 16, the third time t3 = 64, and the fourth time t4 = 121, the rate of change ΔT1 of the surface temperature for the first section, the rate of change ΔT2 of the surface temperature for the second section, and the ratio C.

[0163] [Table 5]

[0164] According to Table 5, the ratios C of the four rice straw data D93a, D93b, D93c, and D93d were 0.423, 0.659, 0.675, and 0.637, respectively. The average value of the ratios C was 0.598, and the standard deviation was 0.102.

[0165] FIG. 14 shows the results of converting the four types of rice straw data D93a, D93b, D93c, and D93d shown in FIG. 13 into cubic function approximation curves. In detail, in FIG. 13, the solid line indicates the approximation curve of the rice straw data D93a, the dashed line indicates the approximation curve of the rice straw data D93b, the dashed line indicates the approximation curve of the rice straw data D93c, and the dashed line indicates the approximation curve of the rice straw data D93d. Table 6 shows the surface temperature T (T1, T2, T3, T4) of the sample, the rate of change ΔT1 of the surface temperature for the first section, the rate of change ΔT2 of the surface temperature for the second section, and the ratio C for each of the approximation curves of the four types of rice straw data D93a, D93b, D93c, and D93d when the first time t1=1, the second time t2=16, the third time t3=64, and the fourth time t4=121. Each data shown in Table 6 corresponds to a value calculated by converting each raw data value shown in Table 5 into an approximation curve of a cubic function.

[0166] [Table 6]

[0167] According to Table 6, the ratios C of the approximation curves of the four types of rice straw data D93a, D93b, D93c, and D93d were 0.485, 0.653, 0.600, and 0.663, respectively. The average value of the ratios C was 0.600, and the standard deviation was 0.071. In other words, compared to the ratios C based on the actual measured values ​​shown in Table 5, the standard deviation can be reduced, and a more reproducible ratio C can be obtained.

[0168] In addition, after calculating differential equations for the approximation curves of the four types of rice straw data D93a, D93b, D93c, and D93d shown in Figure 14, the average value of the differential coefficient (the slope of the tangent to the approximation curve) at the first time t1 = 1 and the differential coefficient at the second time t2 = 16 is taken as the change rate ΔT1 of the surface temperature for the first interval, and the average value of the differential coefficient at the third time t3 = 64 and the differential coefficient at the fourth time t4 = 121 is taken as the change rate ΔT2 of the surface temperature for the second interval. The ratio C is shown in Table 7. Each data shown in Table 7 corresponds to a value calculated by converting the approximation curves of each data shown in Table 6 into differential coefficients.

[0169] [Table 7]

[0170] According to Table 7, the ratios C based on the average values ​​of the differential coefficients for the approximation curves of the four types of rice straw data D93a, D93b, D93c, and D93d were 0.461, 0.594, 0.529, and 0.648, respectively. The average value of the ratios C was 0.558, and the standard deviation was 0.070. In other words, compared with the ratios C based on the actual measured values ​​shown in Table 5 and the ratios C based on the approximation curves shown in Table 6, the standard deviation can be reduced, and a more reproducible ratio C can be obtained.

[0171] Also, FIG. 15 shows rice straw soil data D94 indicating the measured values obtained by the measuring device 3 when using soil for rice straw. The rice straw soil data D94 includes five types of rice straw soil data D94a, D94b, D94c, D94d, and D94e showing the experimental results regarding five samples of soil for rice straw. Further, for each of the five types of rice straw soil data D94a, D94b, D94c, D94d, and D94e, when the first time t1 = 1, the second time t2 = 16, the third time t3 = 64, and the fourth time t4 = 121, the surface temperature T (T1, T2, T3, T4) of the sample, the change rate ΔT1 of the surface temperature for the first section, the change rate ΔT2 of the surface temperature for the second section, and the ratio C are shown in Table 8.

[0172]

Table 8

[0173] According to Table 8, the ratio C of each of the five types of rice straw soil data D94a, D94b, D94c, D94d, and D94e was 1.411, 1.030, 1.078, 0.919, and 1.175. Also, the average value of the ratio C at this time was 1.122, and the standard deviation was 0.166.

[0174] That is, when the soil improvement material identification unit 24 uses a numerical value such as a preset constant "1 (where 0 < C ≤ 1)", a threshold value "1 or more", or a threshold value "0.8 to 1.2" as a reference value, that is, when the slope of the surface temperature with respect to the square root of time can be regarded as having changed little over time, the measurement target can be identified as soil (soil for rice straw). Also, when the ratio C is, for example, a value lower than the above-described preset reference value, that is, when the slope of the surface temperature with respect to the square root of time can be regarded as decreasing over time, the measurement target can be identified as rice straw, which is a porous material. Therefore, the soil improvement material identification device 1 can identify soil and rice straw, which is a soil improvement material of a porous material, by a highly robust identification method based on the ratio C obtained by comparing a plurality of change rates ΔT1 and ΔT2 of temperature.

[0175] <Experimental results: Perlite, soil for perlite> Next, perlite data D95 showing actual measurements by the measuring device 3 when perlite is used is shown in FIG. 16. The perlite data D95 includes five types of perlite data D95a, D95b, D95c, D95d, and D95e showing experimental results for five samples of perlite. In addition, for each of the five types of perlite data D95a, D95b, D95c, D95d, and D95e, the surface temperatures T (T1, T2, T3, and T4) of the samples when the first time t1 is 1, the second time t2 is 16, the third time t3 is 64, and the fourth time t4 is 121, the change rate ΔT1 of the surface temperature for the first section, the change rate ΔT2 of the surface temperature for the second section, and the ratio C are shown in Table 9.

[0176] [Table 9]

[0177] According to Table 9, the ratios C of the five types of pearlite data D95a, D95b, D95c, D95d, and D95e were 0.591, 0.596, 0.746, 0.661, and 0.709, respectively. The average value of the ratios C was 0.660, and the standard deviation was 0.061.

[0178] Moreover, the results of converting the five types of pearlite data D95a, D95b, D95c, D95d, and D95e shown in Fig. 16 into cubic function approximation curves are shown in Fig. 17. In detail, in Fig. 16, the solid line indicates the approximation curve of the pearlite data D95a, the dashed line indicates the approximation curve of the pearlite data D95b, the one-dot chain line indicates the approximation curve of the pearlite data D95c, the two-dot chain line indicates the approximation curve of the pearlite data D95d, and the long chain line indicates the approximation curve of the pearlite data D95e. For each of the approximation curves of the five types of pearlite data D95a, D95b, D95c, D95d, and D95e, the surface temperatures T (T1, T2, T3, T4) of the samples when the first time t1 = 1, the second time t2 = 16, the third time t3 = 64, and the fourth time t4 = 121, the change rate ΔT1 of the surface temperature for the first section, the change rate ΔT2 of the surface temperature for the second section, and the ratio C are shown in Table 10. Each data shown in Table 10 corresponds to a value calculated by converting the value of each raw data shown in Table 9 into the approximation curve of a cubic function.

[0179] [Table 10]

[0180] According to Table 10, the ratios C of the approximation curves of the five types of pearlite data D95a, D95b, D95c, D95d, and D95e were 0.496, 0.578, 0.664, 0.659, and 0.664, respectively. The average value of the ratios C at this time was 0.612, and the standard deviation was 0.067. That is, compared to the ratios C based on the actual measured values ​​shown in Table 9, the standard deviation is not reduced, but it is possible to approximate to a cubic function while keeping the standard deviation at the same level, and a more reproducible ratio C can be obtained based on a formula with a relatively low processing load.

[0181] 17, the average value of the differential coefficient (the slope of the tangent to the approximate curve) at the first time t1=1 and the differential coefficient at the second time t2=16 is taken as the rate of change ΔT1 of the surface temperature for the first interval, and the average value of the differential coefficient at the third time t3=64 and the differential coefficient at the fourth time t4=121 is taken as the rate of change ΔT2 of the surface temperature for the second interval. The ratio C is shown in Table 11. Each data shown in Table 11 corresponds to a value calculated by converting the approximate curve of each data shown in Table 10 into a differential coefficient.

[0182] [Table 11]

[0183] According to Table 11, the ratios C based on the average values ​​of the differential coefficients for the approximation curves of five kinds of pearlite data D95a, D95b, D95c, D95d, and D95e were 0.475, 0.560, 0.639, 0.643, and 0.639. The average value of the ratio C at this time was 0.591, and the standard deviation was 0.066. That is, compared to the ratio C based on the actual measured values ​​shown in Table 9, the standard deviation is not reduced, but it can be approximated to a cubic function while keeping the standard deviation at the same level, and a more reproducible ratio C can be obtained based on a formula with a relatively low processing load. In addition, compared to the ratio C based on the approximation curve shown in Table 10, the standard deviation can be reduced, and a more reproducible ratio C can be obtained.

[0184] Further, Fig. 18 shows perlite soil data D96 indicating the measured values obtained by the measuring instrument 3 when using soil for perlite. The perlite soil data D96 includes five types of perlite soil data D96a, D96b, D96c, D96d, and D96e showing the experimental results regarding the soil for five samples of charcoal. Also, for each of the five types of perlite soil data D96a, D96b, D96c, D96d, and D96e, when the first time t1 = 1, the second time t2 = 16, the third time t3 = 64, and the fourth time t4 = 121, the surface temperature T (T1, T2, T3, T4) of the sample, the change rate ΔT1 of the surface temperature for the first section, the change rate ΔT2 of the surface temperature for the second section, and the ratio C are shown in Table 12.

[0185]

Table 12

[0186] According to Table 12, the ratios C of each of the five types of perlite soil data D96a, D96b, D96c, D96d, and D96e were 1.000, 0.907, 1.120, 1.092, and 1.091. Also, the average value of the ratio C at this time was 1.042, and the standard deviation was 0.079.

[0187] That is, when the soil improvement material identification unit 24 uses, for example, numerical values such as a preset constant "1 (where 0 < C ≤ 1)", a threshold value "1 or more", and a threshold value "0.8 to 1.2" as reference values, that is, when it can be considered that the slope of the surface temperature with respect to the square root of time does not change significantly over time, the measurement target can be identified as soil (soil for perlite). Also, when the ratio C is, for example, a value lower than the above-mentioned preset reference value, that is, when it can be considered that the slope of the surface temperature with respect to the square root of time decreases over time, the measurement target can be identified as perlite, which is a porous material. Therefore, the soil improvement material identification device 1 can identify soil and perlite, which is a soil improvement material of a porous material, by a highly robust identification method based on the ratio C obtained by comparing multiple change rates ΔT1 and ΔT2 of temperature.

[0188] <Experimental results: Recognition accuracy of soil improvement material identification device 1> Next, the identification results of the soil improvement material identification device 1 in the case where soil and a porous soil improvement material were mixed were compared with the mixture ratio of the soil and the porous soil improvement material in the sample to confirm the identification accuracy of the soil improvement material identification device 1. Note that charcoal and rice straw were used as the porous materials in this experiment.

[0189] Fig. 19 shows the relationship between the mixing ratio of the soil in the sample and the soil improvement material made of porous material, and the identification results of the soil improvement material identification device 1. The circular plots in Fig. 19 indicate charcoal data D91, and the triangular plots indicate rice straw data D93. In Fig. 19, the horizontal axis indicates the sample mixing ratio (the actual mixing ratio in the sample), and the vertical axis indicates the estimated mixing ratio output by the soil improvement material identification device 1.

[0190] The estimated mixing ratio indicates the ratio when soil improvement materials are identified for each image block of the surface temperature image D2c for combinations of charcoal and rice straw at multiple mixing ratios. In other words, the estimated mixing ratio indicates the ratio of the number of image blocks identified as porous materials by the soil improvement material identification device 1 to the number of image blocks corresponding to soil, expressed as an area ratio of the sample surface.

[0191] The sample mixing ratio is the volume ratio of the porous material contained in the soil sample, and is therefore not the same as the estimated mixing ratio, which indicates the surface area ratio of the sample.

[0192] However, according to Fig. 19, the estimated mixing ratio tends to change depending on the ratio of the sample mixing ratio. In Fig. 19, an approximation line (solid line) for the charcoal data D91 and an approximation line (dashed line) for the rice straw data D93 are shown, and both plots show a correlation with the approximation line, and a linear correlation can be confirmed with respect to the change in the ratio of the sample mixing ratio. In addition, it was confirmed that the rice straw has the same hue as the soil, but the estimated value changes depending on the actual volume ratio, which shows that the soil improvement material identification device 1 is an identification method that is not affected by color.

[0193] According to the above experimental results, it is considered that the identification accuracy of the soil improvement material identification device 1 can provide practical identification accuracy for identifying soil improvement materials in the cultivation soil S0.

[0194] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0195] 1. Soil improvement material identification device 2. Control equipment 20. Cabinet 201 CPU 202 ROM 203 RAM 204 Preservation Department 205 Interface 210 Internal Bus 21 First Communications Department 22 1st memory section 23 Temperature change rate information acquisition unit 24 Soil Improvement Materials Identification Section 25 Reception 26 Output section 3 Measuring equipment 31 2nd Communications Department 32 2nd memory section 33 Surface temperature information acquisition section 4 Heating equipment 41 Third Communications Department 42 Third memory section 43 Heating section 9 Transmission Line Soil for cultivation U User S11 Heating process S12 Surface temperature information acquisition section S13 Temperature change rate information acquisition process S14 Soil improvement material identification process D1 Setting information D1a Measurement Condition Information D1b Heating condition information D2 measurement information D2a surface temperature information D2b time information D2c surface temperature image D3 Temperature change rate information D3a First temperature change rate information D3b Second temperature change rate information D3c Ratio Information D4 Output Information D4a Soil improvement material identification information D6 Database D61 Reference ratio information D62 Soil improvement material identification information for reference T61 Ratio Information Table T62 Identification Information Table

Claims

1. A soil improvement material identification device for identifying soil and soil improvement materials contained in cultivation soil, A heating unit that heats the surface of the cultivation soil at a substantially constant intensity; A surface temperature information acquisition unit that acquires surface temperature information indicating the surface temperature of the cultivation soil in chronological order by linking the surface temperature information to time information indicating the square root of the time based on the start time of heating by the heating unit; a temperature change rate information acquisition unit that acquires first temperature change rate information indicating a change rate of the surface temperature for a first interval based on a square root of a first time and a square root of a second time later than the first time included in the time information acquired by the surface temperature information acquisition unit, and second temperature change rate information indicating a change rate of the surface temperature for a second interval based on a square root of a third time later than the first time included in the time information and a square root of a fourth time later than the second time and the third time; a soil improvement material identification unit that identifies the soil and the soil improvement material contained in the surface of the cultivation soil based on a ratio between the change rate included in the first temperature change rate information acquired by the temperature change rate information acquisition unit and the change rate included in the second temperature change rate information; To be prepared A soil improvement material identification device comprising:

2. The surface temperature information acquisition unit acquires a surface temperature image that shows the surface temperature information in a two-dimensional image, the temperature change rate information acquisition unit acquires the first temperature change rate information and the second temperature change rate information for each of a plurality of image blocks generated by dividing the surface temperature image, the soil improvement material identification unit identifies a ratio of the number of image blocks of the soil improvement material identified for each image block to the number of image blocks corresponding to the cultivation soil based on a ratio between a change rate included in the first temperature change rate information and a change rate included in the second temperature change rate information.

2. The soil improvement material identification device according to claim 1,

3. The surface temperature information acquisition unit acquires a surface temperature image that shows the surface temperature information in a two-dimensional image, the temperature change rate information acquisition unit acquires the first temperature change rate information and the second temperature change rate information for each of a plurality of image blocks generated by dividing the surface temperature image, the soil improvement material identification unit identifies a relative position of the soil improvement material identified for each image block based on the first temperature change rate information and the second temperature change rate information with respect to the surface temperature image.

2. The soil improvement material identification device according to claim 1,

4. The soil improvement material identification unit refers to a database in which reference ratio information corresponding to ratio information indicating a ratio between the first temperature change rate information and the second temperature change rate information acquired by the temperature change rate information acquisition unit and reference soil improvement material identification information corresponding to soil improvement material identification information indicating information for identifying the soil improvement material are linked in advance, and estimates the soil improvement material based on the soil improvement material identification information corresponding to the ratio information. The soil improvement material identification device according to any one of claims 1 to 3,

5. A method for identifying soil and soil improvement materials contained in cultivation soil, comprising: A heating step of heating the surface of the cultivation soil at a substantially constant intensity; a surface temperature information acquisition process for acquiring surface temperature information indicating the surface temperature of the cultivation soil in chronological order by linking the surface temperature information to time information indicating the square root of the time based on the start time of heating in the heating process; a temperature change rate information acquisition process for acquiring first temperature change rate information indicating a change rate of the surface temperature for a first interval based on a square root of a first time included in the time information acquired by the surface temperature information acquisition process and a square root of a second time later than the first time, and second temperature change rate information indicating a change rate of the surface temperature for a second interval based on a square root of a third time included in the time information and a square root of a fourth time later than the second time and the third time; a soil improvement material identification step of identifying the soil and the soil improvement material contained in the surface of the cultivation soil based on a ratio between the change rate contained in the first temperature change rate information acquired in the temperature change rate information acquisition step and the change rate contained in the second temperature change rate information; Having A method for identifying soil improvement materials, comprising:

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