Artificial seawater generator

Abstract

This artificial seawater generator comprises: a tank that is formed in a cylindrical shape and stores seawater therein; a roller base that supports the tank so as to be rotatable in the circumferential direction; a sensor that measures the state of the seawater in the tank; and a control circuit that controls the operation of the tank.

Description

Artificial seawater generation apparatus

[0001] The present technology relates to an artificial seawater generation apparatus, and particularly to a technology for reproducing the state of seawater.

[0002] An apparatus that generates marine particles by enclosing seawater in a cylindrical tank and rotating the tank on a roller table has been proposed (see, for example, Non-Patent Document 1).

[0003] A. L. Shanks & E. W. Edmondson, “Laboratory-made artificial marine snow: a biological model of the real thing”, Marine Biology, 1989, Volume 101, pages 463-470

[0004] Incidentally, various sensors are used to measure the state of seawater stored in the tank. When measuring the state of seawater in the tank using such a sensor, it is desired to improve measurement accuracy.

[0005] Therefore, an object of the present technology is to accurately measure the state of seawater in a tank.

[0006] The artificial seawater generation apparatus according to the present technology includes: a tank formed in a cylindrical shape and storing seawater therein; a roller table that rotatably supports the tank in a circumferential direction thereof; a sensor that measures the state of seawater in the tank; and a control circuit that controls the state of the tank.

[0007] FIG. 1 is a diagram showing the configuration of an artificial seawater generation apparatus according to an embodiment of the present technology; FIG. 2 is a front perspective view of the artificial seawater generator; FIG. 3 is a rear perspective view of the artificial seawater generator; FIG. 4 is a cross-sectional view passing through the rotation axis of a tank and a water supply and drainage device; FIG. 5 is a perspective view showing a part of the water supply and drainage device; FIG. 6 is a diagram showing an example of a sensor; FIG. 7 is a diagram showing the measurement range of an optical sensor; FIG. 8 is a block diagram showing a hardware configuration example of a control device; FIG. 9 is a block diagram showing a functional configuration of a control circuit; FIG. 10 is a diagram illustrating rotation control of the tank; FIG. 11 is a flowchart showing the flow of marine particle generation processing; and FIG. 12 is a flowchart showing the flow of seawater state estimation model generation processing.

[0008] The embodiments will be described below in the following order. <1. Configuration of the Artificial Seawater Generator> [1.1. Overall Configuration of the Artificial Seawater Generator] [1.2. Configuration of the Artificial Seawater Generator] [1.3. Sensor Configuration] [1.4. Control Device Configuration] [1.5. Functional Configuration of the Control Circuit] [1.6. Artificial Seawater Generation Process] [1.7. Seawater State Estimation Model Generation Process] <2. Modified Examples> <3. Summary> <4. This Technology>

[0009] <1. Configuration of the Artificial Seawater Generator> [1.1. Overall Configuration of the Artificial Seawater Generator] Figure 1 is a diagram showing the configuration of the artificial seawater generator 1 as an embodiment of the present technology. As shown in Figure 1, the artificial seawater generator 1 comprises an artificial seawater generator 2, a sensor 3, a lighting device 4, a control device 5, a water quality control device 6, and a pump 7.

[0010] The artificial seawater generator 2 comprises a tank 11, a roller stand 12, and a water supply / drainage device 13. In the artificial seawater generator 2, the tank 11 is rotated circumferentially by the roller stand 12 while the tank 11 is filled with seawater. The water supply / drainage device 13 is also connected to the tank 11, and it is possible to supply and drain seawater into the tank 11 via the water supply / drainage device 13 while the tank 11 is rotating. As a result, the artificial seawater generator 2 can control the state of the seawater by introducing seawater in a predetermined state into the tank 11.

[0011] The following description primarily focuses on the use of the artificial seawater generator 2 to generate marine particles. The artificial seawater generator 2 is used to periodically and over the long term to measure (observe) the state of seawater by reproducing the actual state of seawater. For example, the artificial seawater generator 2 can be used to measure various seawater conditions, such as observing the ecology of organisms like phytoplankton and zooplankton, organic particles of biological origin such as animal feces and carcasses, inorganic particles of mineral origin, anthropogenic particles from microplastics, petroleum, oils and other industrial emissions, and crystallized dissolved substances. This makes it possible to estimate the state of seawater indoors, which is difficult to measure in the field.

[0012] Here, "seawater condition" includes the state and composition (components and their concentrations) of the seawater itself, as well as the state and composition of marine particles. The state of the seawater itself includes physical information about the seawater, such as temperature, pressure, and current velocity. The composition of the seawater itself includes information about the components of the seawater. The state of the particles includes information for identifying the particles, such as their type, shape, and size. The composition of the particles includes information about the components that make up the particles. Furthermore, "measurement" refers to measurements related to the state and composition of the seawater itself, as well as the state and composition of marine particles, and is a concept that includes, for example, the identification of the type or characteristics of marine particles, and the recording and storage of imaging images of seawater. Furthermore, marine particles refer to all particles floating in seawater. Marine particles can be classified into inorganic particles of mineral origin, organic particles of biological origin, artificially originated particles, and salts that have crystallized from dissolved salts. Inorganic particles include sand, silt, and clay, which are sediments from rivers and the seabed, volcanic ash, which are fine particles released by volcanic activity, and metal oxides such as iron and manganese oxides that have precipitated in the sea. Organic particles include zooplankton, phytoplankton, microscopic algae, microorganisms such as bacteria and viruses that are abundant in seawater, the feces and carcasses of organisms that float as organic matter, and marine snow, which is an accumulation of the feces and carcasses of organisms. Artificial particles include microplastics, which are finely divided plastics that have degraded, industrial emissions such as metal particles and chemical substances that have fallen from the atmosphere, particles derived from petroleum and oils that affect marine pollution, aquaculture feed, and agricultural fertilizers and preparations. Salts include salt crystals that are produced as seawater evaporates, calcium carbonate which is fragments of coral and seashells, and silicates which are the shells of diatoms. Among marine particles, sinking particles refer to all particles that sink in the ocean due to gravity. One type of sinking particle is an aggregate called marine snow, which is suspended matter in the sea, and is formed when the carcasses and feces of plankton and tiny organic matter in seawater are bound together by mucus, etc., into flake-like or lumpy forms. The following explanation will use marine snow as an example of marine particles, but marine particles may be other types of marine particles.

[0013] The seawater supplied to tank 11 includes artificially generated seawater and seawater brought from the actual ocean. In the following, the seawater supplied to tank 11 will be referred to as artificial seawater, but this is not limited to artificially generated seawater.

[0014] Artificially produced seawater contains water, salts, nutrients, gases, metals, and organic matter. Salts include sodium chloride, magnesium chloride, magnesium sulfate, calcium sulfate, and trace amounts of calcium carbonate. Nutrients include nitrates, phosphates, and silicates. Gases include oxygen, carbon dioxide, and nitrogen. Metals include potassium, bromine, boron, and strontium. Organic matter includes organisms such as phytoplankton and zooplankton, as well as their feces, carcasses, and decomposed materials.

[0015] Sensor 3 comprehensively represents one or more sensors that optically, chemically, and physically measure the state of the artificial seawater in tank 11. Sensor 3 measures the state of the artificial seawater in tank 11 and outputs the measurement results to control device 5.

[0016] The lighting device 4 illuminates the tank 11 with light. The lighting device 4 comprehensively represents various lighting devices, such as a lighting device that illuminates the bottom of the tank 11 with light, and a lighting device that illuminates the side of the tank 11 with a sheet-like light.

[0017] The control device 5 is a computer including a control circuit, which controls the drive of the roller stand 12, i.e., the rotational movement of the tank 11. The control device 5 also controls the intensity of the light emitted from the lighting device 4, the lighting pattern, etc. Furthermore, if the pump 7 is an electric pump, the control device 5 adjusts the amount of artificial seawater supplied to and drained from the tank 11 by driving and controlling the pump 7.

[0018] Furthermore, the control device 5 performs machine learning based on the seawater conditions of the artificial seawater measured by the sensor 3 and generates a seawater condition estimation model. The seawater condition estimation model is a model (software) that estimates the seawater conditions when the seawater conditions and composition are specified. For example, when the seawater conditions and composition are specified, the seawater condition estimation model can estimate the size, composition, and number of marine particles generated by that seawater.

[0019] The water quality control device 6 is a device for adjusting the state and composition of the artificial seawater supplied to the tank 11 to a preset target value. The water quality control device 6 includes, for example, a heater or cooler for adjusting the temperature of the artificial seawater, and an air pump for adjusting the amount of dissolved oxygen in the artificial seawater.

[0020] The water quality control device 6 may, for example, heat the artificial seawater with a heater to a predetermined target temperature, or operate an air pump to bring the artificial seawater to a predetermined target dissolved oxygen level. The operation of the water quality control device 6 may be controlled by the control device 5, or by other control devices.

[0021] The artificial seawater, whose water quality has been adjusted by the water quality control device 6, is supplied into the tank 11 through the water supply and drainage device 13. The water quality control device 6 may also be configured to adjust the water quality of the artificial seawater discharged from the tank 11.

[0022] Pump 7 is, for example, an electric pump and is driven and controlled by the control device 5. However, pump 7 may also be driven by, for example, the user.

[0023] [1.2. Configuration of the Artificial Seawater Generator] Figure 2 is a front perspective view of the artificial seawater generator 2. Figure 3 is a rear perspective view of the artificial seawater generator 2. Figure 4 is a cross-sectional view passing through the rotation axis of the tank 11 and the water supply and drainage device 13. Note that the internal structure of the rotary supply mechanism 31 is omitted in Figure 4. In the following description, the first bottom 22 side of the tank 11 will be referred to as the front direction, the second bottom 23 side of the tank 11 as the rear direction, the right side when viewed from the first bottom 22 side as the right direction, the left side when viewed from the first bottom 22 side as the left direction, the vertically upward direction as the up direction, and the vertically downward direction as the down direction.

[0024] As shown in Figures 2, 3, and 4, the tank 11 comprises a main body 21, a first bottom 22, and a second bottom 23. The main body 21, the first bottom 22, and the second bottom 23 are formed of a colorless, transparent resin material. However, the tank 11 may be made of a material other than resin, and it does not have to be colorless and transparent.

[0025] The main body portion 21 is formed in a cylindrical shape with a roughly U-shaped cross-section. The main body portion 21 is formed so that its thickness in the front-to-back direction is shorter than its diameter up to the side surface 21a.

[0026] O-ring grooves 21d are formed in the front flange portion 21b and the rear flange portion 21c of the main body portion 21, extending circumferentially. An O-ring 24 is inserted into the O-ring groove 21d. In addition, multiple screw grooves 21e for screwing in the fastening member 25 are formed in the flange portions 21b and 21c at equal intervals along the circumferential direction.

[0027] A pair of through holes 21f are formed on the side surface 21a at positions 180 degrees apart in the circumferential direction. A sealing member 26 is detachably screwed into the through holes 21f. In the artificial seawater generator 2, by removing the sealing member 26 from the main body 21, it is possible to easily remove the artificial seawater from the main body 21 or easily put materials into the main body 21. However, the artificial seawater generator 2 does not necessarily have to be provided with through holes 21f and sealing members 26.

[0028] The first bottom portion 22 abuts against the flange portion 21b from the front. The first bottom portion 22 is formed in a disc shape with a diameter larger than the diameter of the O-ring groove 21d, and covers the front bottom surface of the main body portion 21. An O-ring 24 is sandwiched between the flange portion 21b and the first bottom portion 22. This prevents the artificial seawater contained in the internal space of the main body portion 21 from leaking out from between the flange portion 21b and the first bottom portion 22. Furthermore, through holes 22a are formed in the first bottom portion 22 at positions corresponding to the screw grooves 21e in the flange portion 21b. With the first bottom portion 22 abutting against the flange portion 21b, the fastening member 25 is inserted into the through hole 22a and then screwed into the screw grooves 21e, causing the first bottom portion 22 to be tightly fitted to the main body portion 21.

[0029] The second bottom portion 23 abuts against the flange portion 21b from the rear. The second bottom portion 23 is formed in a disc shape with a diameter larger than the diameter of the O-ring groove 21d, and covers the rear bottom surface of the main body portion 21. An O-ring 24 is sandwiched between the flange portion 21c and the second bottom portion 23. This prevents the artificial seawater contained in the internal space of the main body portion 21 from leaking out from between the flange portion 21c and the second bottom portion 23. Furthermore, through holes 23a are formed in the second bottom portion 23 at positions corresponding to the screw grooves 21e in the flange portion 21c. With the second bottom portion 23 abutting against the flange portion 21c, the fastening member 25 is inserted into the through hole 23a and then screwed into the screw grooves 21e, causing the second bottom portion 23 to be tightly fitted to the main body portion 21. In the center of the second bottom portion 23, a projection 23b is formed that protrudes to the rearward side for fixing the water supply and drainage device 13, and a through-hole 23c is also formed. The center of the through-hole 23c coincides with the rotation axis of the tank 11.

[0030] In this way, the internal space 27 surrounded by the main body 21, the first bottom 22, and the second bottom 23 of the tank 11 is sealed, making it possible to store artificial seawater in the internal space 27.

[0031] The inner surfaces of the side 21a, first bottom 22, and second bottom 23 facing the internal space 27 are coated with fluorine. Therefore, in the tank 11, when artificial seawater is stored in the internal space 27, it is possible to reduce the adhesion of particles and air bubbles contained in the artificial seawater to these inner surfaces. However, the inner surfaces of the side 21a, first bottom 22, and second bottom 23 facing the internal space 27 do not necessarily have to be coated with fluorine.

[0032] Furthermore, the outer surfaces of the main body 21, the first bottom portion 22, and the second bottom portion 23 that are opposite to the inner surfaces are coated with an anti-reflective coating. This reduces the reflection of light emitted from the illumination device 4 from these outer surfaces, thereby reducing noise during measurement.

[0033] The water supply and drainage device 13 is a device that supplies artificial seawater into the tank 11 and discharges the artificial seawater from the tank 11. The water supply and drainage device 13 comprises a rotary supply mechanism 31, a connecting member 32, a fixing member 33, a water supply pipe 34, a drain pipe 35, a water supply pipe 36, a drain pipe 37, a water supply valve 38, a drain valve 39, a water supply pipe 40, a drain hole 41, and a mesh filter 42.

[0034] The rotary supply mechanism 31 is a mechanism that can rotate while supplying and discharging liquid or gas, and is, for example, a rotary manifold. The rotary supply mechanism 31 comprises a rotating part 31a and a stationary part 31b. The rotating part 31a is rotatable relative to the stationary part 31b. The rotating part 31a and the stationary part 31b are provided with the same number of connection ports, and the connection ports of a pair of rotating parts 31a and the connection ports of the stationary part 31b are connected by an internal circuit.

[0035] Specifically, the two connection ports of the rotating section 31a are connected to the water supply pipe 34 and the drain pipe 35, respectively, and the two connection ports of the fixed section 31b are connected to the water supply pipe 36 and the drain pipe 37, respectively. The rotary supply mechanism 31 connects the water supply pipe 34 and the water supply pipe 36 by an internal circuit, and also connects the drain pipe 35 and the drain pipe 37 by an internal circuit. As a result, the rotary supply mechanism 31 can circulate artificial seawater from the water supply pipe 36 to the water supply pipe 34, and from the drain pipe 35 to the drain pipe 37, even when the rotating section 31a and the fixed section 31b are rotating relative to each other.

[0036] The connecting member 32 is inserted into the central through hole 23c of the second bottom portion 23 and fixed to the protruding portion 23b by fastening members 43 such as screws. The rotating portion 31a of the rotary feeding mechanism 31 is fixed to the connecting member 32 via a fixing member 33. At this time, the rotation axis of the rotary feeding mechanism 31 is positioned coaxially with the rotation axis of the tank 11.

[0037] The water supply valve 38 is located in the middle of the water supply pipe 36. When the water supply valve 38 is open, it allows the supply of artificial seawater to the tank 11, and when it is closed, it shuts off the supply of artificial seawater to the tank 11. The water supply valve 38 may be manually switched open and closed by the user. Alternatively, the water supply valve 38 may be an electric valve and its opening and closing may be controlled by the control device 5.

[0038] The drain valve 39 is installed in the middle of the drain pipe 37. When the drain valve 39 is open, it allows the discharge of artificial seawater from the tank 11, and when it is closed, it blocks the discharge of artificial seawater from the tank 11. The drain valve 39 may be manually switched open and closed by the user. Alternatively, 39 may be an electric valve and its opening and closing may be controlled by the control device 5.

[0039] A through-hole is formed in the center of the connecting member 32, and a water supply pipe 34 is connected to this through-hole from the rear, and a water supply pipe 40 is inserted into it. The water supply pipe 40 is fixed to the connecting member 32 so as to protrude into the tank 11.

[0040] Figure 5 is a perspective view showing a part of the water supply and drainage device 13. As shown in Figures 4 and 5, the water supply pipe 40 is positioned along the axis of rotation of the tank 11, i.e., the center of rotation, and extends from the axial center of the main body 21 to the first bottom 22. In other words, the tip of the water supply pipe 40 extends forward from the center of the tank 11 in the front-rear direction, reaching near the first bottom 22. The water supply pipe 40 discharges artificial seawater supplied from the water supply pipe 34 into the tank 11.

[0041] The tip of the water supply pipe 40 (water inlet) should be positioned as far away from the drain hole 41 as possible. This reduces the likelihood of artificial seawater released from the water supply pipe 40 being immediately discharged from the drain hole 41.

[0042] Four fan-shaped drainage holes 41 are provided around the through-hole in the connecting member 32 into which the water supply pipe 40 is inserted. The cross-sectional area of ​​each drainage hole 41 is larger than the cross-sectional area of ​​the water supply pipe 40. The four drainage holes 41 are connected to each other inside the connecting member 32 and are also connected to the drain pipe 35. The drainage holes 41 discharge the artificial seawater in the tank 11 into the drain pipe 35. Note that the shape and number of drainage holes 41 are just examples, and they may be of other shapes or any number. However, it is desirable that the total cross-sectional area of ​​the drainage holes 41 be sufficiently larger than the cross-sectional area of ​​the water supply pipe 40 so as to minimize the water flow generated when discharging the artificial seawater from the tank 11.

[0043] A mesh filter 42 is attached to the side surface of the connecting member 32 on which the drain hole 41 is formed. The mesh filter 42 covers the drain hole 41 and traps particles contained in the artificial seawater in the tank 11. In the artificial seawater generator 2, if particles contained in the artificial seawater in the tank 11 are discharged to the outside, actual seawater cannot be accurately reproduced, so the mesh filter 42 prevents the particles from being discharged to the outside.

[0044] The roller table 12 includes a fixed table 51, rollers 52, a belt 53, a motor 54, a support column 55, and a guide 56, and supports the tank 11 rotatably in the circumferential direction.

[0045] In the roller table 12, a pair of rollers 52 are rotatably provided on the fixed table 51 so as to be spaced apart in the left-right direction. A belt 53 is stretched across the pair of rollers 52, and the pair of rollers 52 can rotate synchronously through the belt 53. The tank 11 is rotatably placed on the pair of rollers 52. Note that the roller table 12 does not necessarily need to be provided with the belt 53.

[0046] A motor 54 is connected to one of the rollers 52. The driving of the motor 54 is controlled under the control of the control device 5. When the motor 54 is driven, the pair of rollers 52 rotate, and the tank 11 placed on the pair of rollers 52 rotates.

[0047] The support column 55 is fixed to the fixed table 51 at a position behind the pair of rollers 52 and in the center between the pair of rollers 52. The support column 55 is a plate-shaped member extending in the vertical direction. A guide 56 is attached to the upper end of the support column 55.

[0048] A linear slider (not shown) is provided between the support column 55 and the guide 56, and the guide 56 is attached to the support column 55 so as to be movable in the vertical direction and the left-right direction. The guide 56 supports the fixed portion 31b of the rotary supply mechanism 31 movably in a direction perpendicular to the axial direction, that is, in the vertical direction and the left-right direction. Accordingly, even if the rotary supply mechanism 31 slightly moves in a direction perpendicular to the axial direction (front-rear direction) along with the rotation of the tank 11, the movement can be absorbed by the guide 56.

[0049] Although the roller table 12 is provided as a rotation mechanism for rotating the tank 11, this is merely an example, and other rotation mechanisms may be employed, such as one in which a motor is directly connected to the tank 11 and the tank 11 is rotated by the motor. Further, although the water supply and drainage device 13 is provided as a mechanism for supplying and draining artificial seawater into and out of the tank 11, this is also merely an example, and any other mechanism may be employed as long as it can supply and drain artificial seawater into and out of the tank 11.

[0050] Further, the water supply and drainage device 13 may reduce the influence of water flow caused by water supply and drainage on marine particles by bringing a water supply hole for supplying artificial seawater into the tank 11 close to the drainage hole 41 without providing the water supply pipe 40. A structure is also conceivable in which both the water supply hole for supplying artificial seawater and the drainage hole 41 are covered with a mesh filter 42, and artificial seawater is circulated on the opposite side of the mesh filter 42 from the internal space 27, thereby preventing marine particles from being adsorbed to the mesh filter 42. In this case, the internal space 27 is brought into contact with the supplied and drained artificial seawater via the mesh filter 42, whereby components of the artificial seawater are exchanged through diffusion.

[0051] [1.3. Configuration of Sensor] FIG. 6 is a diagram showing an example of the sensor 3. The sensor 3 comprehensively refers to sensors for measuring the seawater state of the artificial seawater in the tank 11 by physical, chemical, optical, biological and other methods.

[0052] As shown in Figure 6, the sensors 3 for physically measuring the state of the artificial seawater include a temperature sensor 61, a pressure sensor 62, a conductivity sensor 63, a flow meter 64, and a bioacoustic sensor 65. The temperature sensor 61 measures the temperature of the artificial seawater. The pressure sensor 62 measures the pressure of the artificial seawater. The conductivity sensor 63 measures the conductivity of the artificial seawater. The flow meter 64 measures the flow velocity of the artificial seawater. The bioacoustic sensor 65 measures the sounds emitted from organisms in the artificial seawater.

[0053] Sensors 3 for chemically measuring the state of artificial seawater include a dissolved oxygen sensor 66, a pH sensor 67, a carbon dioxide sensor 68, a nitrate sensor 69, an ammonium sensor 70, a salinity sensor 71, and an oxidation-reduction potential sensor 72. The dissolved oxygen sensor 66 measures the amount of oxygen dissolved in the artificial seawater. The pH sensor 67 measures the pH of the artificial seawater. The carbon dioxide sensor 68 measures the amount of carbon dioxide dissolved in the artificial seawater. The nitrate sensor 69 measures the amount of nitrate dissolved in the artificial seawater. The ammonium sensor 70 measures the amount of ammonium dissolved in the artificial seawater. The salinity sensor 71 measures the amount of salinity dissolved in the artificial seawater. The oxidation-reduction potential sensor 72 measures the oxidation-reduction potential of the artificial seawater.

[0054] Sensors 3 for optically measuring the seawater conditions of artificial seawater include a vision sensor 73, a multispectral camera 74, a camera 75, a particle size distribution sensor 76, a chlorophyll sensor 77, a light transmittance sensor 78, a CDOM (Colored Dissolved Organic Matter) sensor 79, a photosynthetically active radiation sensor 80, and a backscatter sensor 81.

[0055] The vision sensor 73 is a sensor called a DVS (Dynamic Vision Sensor) or EVS (Event-Based Vision Sensor). The vision sensor 73 is an asynchronous image sensor in which multiple pixels having photoelectric conversion elements are arranged in two dimensions, and a detection circuit for detecting address events in real time is provided for each pixel. An address event is an event that occurs in accordance with the amount of incident light for each address assigned to each of the multiple pixels arranged in two dimensions. For example, this could be the current value of the current based on the charge generated by the photoelectric conversion element, or the amount of change thereof, exceeding a certain threshold.

[0056] The vision sensor 73 detects the occurrence of an address event for each pixel by imaging the artificial seawater in the tank 11. If an address event is detected, it reads out the pixel signal as pixel data from the pixel where the address event occurred. In other words, the vision sensor 73 acquires pixel data asynchronously according to the amount of light incident on each of the multiple pixels arranged in two dimensions.

[0057] In the vision sensor 73, the pixel signal readout operation is performed for pixels where an address event has been detected. Therefore, it is possible to read out much faster than a synchronous image sensor, where the readout operation is performed for all pixels at a predetermined frame rate, and the amount of data read out per frame is also small.

[0058] Therefore, by using the vision sensor 73 in the artificial seawater generator 2, it becomes possible to detect moving particles contained in the artificial seawater more quickly. In addition, the vision sensor 73 can reduce the amount of data and also reduce power consumption.

[0059] The multispectral camera 74 measures the spectral information of the light emitted by the artificial seawater. By measuring the spectral information, the artificial seawater generator 2 can detect differences in composition from the reflected and transmitted light of ocean particles.

[0060] The camera 75 is, for example, a CCD (Charge Coupled Device) or CMOS (Complementary Metal-Oxide-Semiconductor) type image sensor, in which multiple pixels having photoelectric conversion elements are arranged in two dimensions. The camera 75 captures a predetermined imaging range at regular intervals according to the frame rate and generates image data. Therefore, the camera 75 can measure (image) particles contained in artificial seawater.

[0061] The particle size distribution sensor 76 measures the particle size distribution of particles in the artificial seawater. The chlorophyll sensor 77 measures the intensity of chlorophyll fluorescence emitted by phytoplankton during photosynthesis in the artificial seawater. The light transmittance sensor 78 measures the light transmittance of the artificial seawater. The CDOM sensor 79 measures the amount of colored dissolved organic matter in the artificial seawater. The photosynthetically active radiation sensor 80 measures the amount of radiation at wavelengths that plants can use for photosynthesis in the artificial seawater. The back scattering sensor 81 measures the size distribution and turbidity of particulate organic matter by measuring back scattered light.

[0062] The sensor 3 for biologically measuring the seawater conditions of artificial seawater includes a DNA sensor 82. The DNA sensor 82 measures the presence or absence or reaction amount of the target DNA in organic matter in the artificial seawater.

[0063] Other sensors 3 used to measure characteristics include an oil content sensor 83, a radiation sensor 84, and an acoustic sensor 85. The oil content sensor 83 measures the amount of oil in the artificial seawater. The radiation sensor 84 measures the amount of radiation in the artificial seawater. The acoustic sensor 85 measures the sound generated in the artificial seawater.

[0064] In the artificial seawater generator 2, one or more sensors from the sensors 3, from the temperature sensor 61 to the acoustic sensor 85, are used as appropriate, depending on the seawater condition of the artificial seawater that the user wants to detect.

[0065] Figure 7 shows the measurement range of the optical sensor. As shown in Figure 7, it is conceivable that the lighting device 4 irradiates a sheet-like light into the tank 11 from the side of the main body 21. The light irradiated from the lighting device 4 spreads in a sheet-like manner in the vertical and horizontal directions, but hardly spreads in the front-to-back direction.

[0066] In this case, since the main body 21 is formed of a transparent resin material in the circumferential direction, the light emitted from the lighting device 4 will always reach the inside of the tank 11, even when the tank 11 is rotating.

[0067] Furthermore, the optical sensor 3 is positioned so that its optical axis is perpendicular to the light emitted from the illumination device 4, i.e., in the front-to-back direction. This allows the artificial seawater generator 1 to measure a predetermined measurement range within the tank 11 that is illuminated by the sheet-like light emitted by the illumination device 4 using the optical sensor 3. Since the position of the sensor 3 is fixed, the measurement range is also fixed. This allows the artificial seawater generator 1 to measure the measurement range using, for example, a vision sensor 73 or a camera 75, and then use the control circuit 91 to detect the size, shape, number, and movement trajectory of particles (e.g., marine particles) present in that measurement range. Based on these detection results, the artificial seawater generator 1 can then accurately detect the size, shape, and number (density) of particles present in the tank 11 using the control circuit 91. Note that a known method can be used to detect the size, shape, number, and movement trajectory of particles from images captured by the vision sensor 73 or camera 75, so its explanation is omitted.

[0068] Furthermore, if the artificial seawater generator 2 is mounted on a mobile vehicle such as an exploration vessel, sensors 3 such as a GNSS (Global Navigation Satellite System) or a 6-axis accelerometer may be provided.

[0069] [1.4. Configuration of the Control Device] Figure 8 is a block diagram showing an example of the hardware configuration of the control device 5. As shown in the figure, the control device 5 is equipped with a control circuit 91. The control circuit 91 is composed of semiconductor circuits such as a CPU (Central Processing Unit) and executes various processes according to a program stored in the ROM 92 or a program loaded from the storage unit 98 into the RAM 93. In addition to the CPU, the control circuit 91 may also be configured to include a GPU (Graphics Processing Unit) for the execution of various image processing.

[0070] The RAM 93 also stores data necessary for the control circuit 91 to perform various processes. The control circuit 91, ROM 92, and RAM 93 are interconnected via the bus 102. An input / output interface (I / F) 94 is also connected to this bus 102.

[0071] An input unit 95, consisting of an operator or operating device, is connected to the input / output interface 94. For example, the input unit 95 can be various operators or operating devices such as a keyboard, mouse, keys, dial, touch panel, touchpad, or remote controller. User operations are detected by the input unit 95, and the signals corresponding to the input operations are interpreted by the control circuit 91.

[0072] Furthermore, a display unit 96, consisting of an LCD or organic EL panel, and an audio output unit 97, consisting of a speaker, are connected to the input / output interface 94, either as an integrated unit or as separate components. The display unit 96 is used for displaying various types of information and is composed of, for example, a display device provided on the casing of a computer device or a separate display device connected to a computer device.

[0073] The display unit 96 displays images for various image processing purposes, such as videos to be processed, on the display screen based on instructions from the control circuit 91. In particular, the display unit 96 displays various operation menus, icons, messages, etc., i.e., GUI (Graphical User Interface) based on instructions from the control circuit 91.

[0074] The input / output interface 94 may also be connected to a storage unit 98 consisting of a non-volatile memory device such as an SSD or HDD, or a communication unit 99 consisting of a modem or the like.

[0075] The communications unit 99 performs communication processing via transmission lines such as the Internet, and communicates with various devices via wired / wireless communication, bus communication, etc.

[0076] A drive 100 is connected to the input / output interface 94 as needed, and a removable recording medium 101 such as a magnetic disk, optical disk, magneto-optical disk, or semiconductor memory is appropriately mounted there.

[0077] The drive 100 can read data (including computer programs, etc.) used for various processes from the removable recording medium 101. The read data is stored in the storage unit 98, or, if the read data is image data or audio data, the image or audio is output by the display unit 96 or the audio output unit 97. The computer program read from the removable recording medium 101 is installed in the storage unit 98 as needed.

[0078] Furthermore, the control device 5 is not limited to being composed of a single computer device as shown in Figure 8, but may be configured as a system of multiple computer devices. The multiple computer devices may be systematized via a LAN (Local Area Network), or they may be located in remote locations via a VPN (Virtual Private Network) using the Internet, etc. The multiple computer devices may include computer devices that function as a group of servers (cloud) available through cloud computing services.

[0079] [1.5. Functional Configuration of Control Circuit 91] Figure 9 is a block diagram showing the functional configuration of the control circuit 91. As shown in Figure 9, the control circuit 91 functions as an operation control unit 111, a measurement control unit 112, and a model generation unit 113.

[0080] The operation control unit 111 controls the operation of the artificial seawater generator 2, the lighting device 4, the water quality control device 6, and the pump 7 so that the artificial seawater in the tank 11 meets conditions predetermined by the user.

[0081] For example, the operation control unit 111 controls the amount of artificial seawater supplied to and drained from the tank 11 by controlling the operation of the pump 7.

[0082] Furthermore, the operation control unit 111 provides feedback control to the water quality control device 6 and the pump 7 based on the measurement results of the sensor 3, so that the state and composition of the artificial seawater supplied to the tank 11 reach preset target values.

[0083] Figure 10 illustrates an example of rotation control of the tank 11. The motion control unit 111 controls the rotation direction and rotation speed of the tank 11 by controlling the operation of the motor 54. For example, as shown in Figure 10, the motion control unit 111 rotates the tank 11 to cause the particles contained in the artificial seawater to form clumps, thereby generating ocean particles 121.

[0084] The ocean particles 121 generated in the tank 11 will fall due to their own weight and settle on the sides of the tank 11 if the tank 11 is not rotating. Therefore, the motion control unit 111 uses the motor 54 to rotate the tank 11 at a constant speed according to the settling speed of the ocean particles 121. As a result, the artificial seawater in the tank 11 rotates along with the rotation of the tank 11, making it possible to keep the ocean particles 121 floating in the artificial seawater without settling.

[0085] Furthermore, the motion control unit 111 may predict the movement trajectory of the ocean particles 121 based on measurement results from, for example, the vision sensor 73 or the camera 75, and perform feedback control to prevent the ocean particles 121 from settling.

[0086] Furthermore, the motion control unit 111 can also control the motor 54 to temporarily stop, reverse rotation, or change the speed of the tank 11. This makes it possible to rapidly change the artificial seawater in the tank 11, causing the ocean particles 121 to disintegrate or deform. In this way, the state and composition of the disintegration process of the ocean particles 121 can be measured by the optical sensor 3.

[0087] Furthermore, the operation control unit 111 may increase the rotation speed of the tank 11 when artificial seawater is being supplied to and drained into the tank 11 by the supply and drainage device 13, compared to when artificial seawater is not being supplied or drained. This makes it possible to agitate the artificial seawater supplied into the tank 11 at an earlier stage.

[0088] Furthermore, the operation control unit 111 may slow down the rotation speed of the tank 11 or stop the rotation of the tank 11 when artificial seawater is being supplied to and drained into the tank 11 by the supply and drainage device 13, compared to when artificial seawater is not being supplied to or drained. This makes it possible to reduce the breakdown or deformation of marine particles by minimizing the water flow generated by the supply and drainage of artificial seawater into and out of the tank 11.

[0089] Furthermore, the operation control unit 111 may reverse the supply and drainage of artificial seawater into the tank 11 by the supply and drainage device 13 when predetermined conditions are met, for example, at predetermined intervals. That is, when predetermined conditions are met, the operation control unit 111 releases artificial seawater into the tank 11 from the drainage hole 41. This makes it possible to return particles clogged in the mesh filter 42 back into the tank 11.

[0090] Furthermore, the operation control unit 111 can also adjust the brightness of the lighting device 4 or the sensitivity of the optical sensor 3 if it exceeds the measurement range of the optical sensor 3.

[0091] Furthermore, the operation control unit 111 may increase the rotation speed of the tank 11 when a predetermined substance is supplied to the tank 11 via the water supply and drainage device 13. The predetermined substance is, for example, feed for zooplankton. This makes it possible to distribute the predetermined substance throughout the tank 11 quickly.

[0092] The measurement control unit 112 has the sensor 3 measure the state of the artificial seawater to be measured and acquires the measurement results.

[0093] The model generation unit 113 uses the measurement results of the artificial seawater state measured by the sensor 3 as training data (teaching data), performs machine learning on the state and composition of the artificial seawater at that time, and generates a seawater state estimation model. The seawater state estimation model is, for example, a model that estimates what kind of ocean particles will be generated depending on the state and composition of the artificial seawater.

[0094] [1.6. Artificial Seawater Generation Process] Figure 11 is a flowchart showing the flow of the artificial seawater generation process. As shown in Figure 11, when the artificial seawater generation process is started, in step S1 the operation control unit 111 acquires measurement results from the sensor 3. In step S2 the operation control unit 111 stores the acquired measurement results in the storage unit 98. In step S3 the measurement control unit 112 controls the artificial seawater generator 2, lighting device 4, water quality control device 6, and pump 7 based on the measurement results acquired from the sensor 3.

[0095] In step S4, the measurement control unit 112 determines whether predetermined measurement termination conditions have been met. These conditions include the user inputting a termination command, the completion of measurement for a predetermined time, the ocean particles reaching a predetermined diameter or greater, and the number of ocean particles reaching a certain level or greater. If the predetermined measurement termination conditions have not been met (No in step S4), the control circuit 91 returns the process to step S1. On the other hand, if the predetermined measurement termination conditions have been met (Yes in step S4), in step S5, the measurement control unit 112 stores the data set of measurement results measured in step S1 as a single learning data in the storage unit 98 and terminates the artificial seawater generation process.

[0096] The artificial seawater generator 1 makes it possible to measure the state and composition of marine particles in various artificial seawater states and compositions by performing the artificial seawater generation process on artificial seawater with different states and compositions.

[0097] [1.7. Seawater State Estimation Model Generation Process] Figure 12 is a flowchart showing the flow of the seawater state estimation model generation process. As shown in Figure 12, when the seawater state estimation model generation process is started, in step S11 the model generation unit 113 determines whether there is training data (teaching data) in a range that has not been used for model generation so far. If there is no training data that has not been used for model generation (No in step S11), the model generation unit 113 terminates the seawater state estimation model generation process.

[0098] If there is training data that has not been used for model generation (Yes in step S11), in step S12 the model generation unit 113 reads the training data that has not been machine-learned from the storage unit 98. In step S13 the model generation unit 113 performs machine learning based on the training data that has not been machine-learned to generate a seawater state estimation model for estimating, for example, the state and composition of ocean particles, and terminates the seawater state estimation model generation process. As a result, the seawater state estimation model can measure the state and composition of ocean particles in various artificial seawater states and compositions. In addition to estimating the state and composition of ocean particles, the seawater state estimation model can also estimate various other seawater states and compositions.

[0099] <2. Modifications> It should be noted that the embodiments are not limited to the specific examples described above, and various other configurations as modifications are possible.

[0100] In the embodiment described above, the tank 11 is constructed by combining separate parts: the main body 21, the first bottom 22, and the second bottom 23. However, the tank 11 may also be constructed such that the main body 21, the first bottom 22, and the second bottom 23 are integrally formed.

[0101] Furthermore, the configuration of the water supply and drainage device 13 in the above-described embodiment is merely an example, and other configurations are also acceptable as long as artificial seawater can be supplied and drained while the tank 11 is rotating.

[0102] Furthermore, in the embodiment described above, the water supply and drainage device 13 is connected to the tank 11, but the water supply and drainage device 13 is not essential.

[0103] <3. Summary> As described above, the artificial seawater generator 1 of the embodiment includes a cylindrical tank 11 that stores seawater inside, a roller base 12 that supports the tank 11 so that it can rotate in the circumferential direction, a sensor 3 that measures the state of the seawater in the tank 11, and a control circuit 91 that controls the operation of the tank 11. As a result, the artificial seawater generator 1 accurately measures the state of the seawater in the tank 11.

[0104] The sides of the tank 11 are made of a transparent material around their entire circumference. This allows the artificial seawater generator 1 to irradiate light from the sides of the tank 11, ensuring that light is constantly irradiated into the tank 11 even while the tank 11 is rotating.

[0105] The artificial seawater generator 1 includes an illumination device 4 that irradiates a sheet of light onto the side of the tank 11. The sensor 3 includes an optical sensor that optically measures a predetermined measurement range within the tank 11 irradiated by the illumination device 4. The optical sensor corresponds to a vision sensor 73 or a camera 74. As a result, the optical sensor can image only the seawater particles within the measurement range irradiated by the illumination device 4. Therefore, in the artificial seawater generator 1, the measurement range is fixed, and the measurement accuracy can be improved.

[0106] The control circuit 91 controls the rotation speed of the tank 11 according to the settling speed of the particles inside the tank 11. This reduces the risk of particles colliding with the sides of the tank 11 and causing it to break down or deform. In other words, it is possible to accurately reproduce and measure the actual seawater conditions.

[0107] Sensor 3 includes an optical sensor that optically measures the seawater in tank 11. The control circuit 91 provides feedback control of the rotation speed of tank 11 according to the settling velocity of the particles measured by the optical sensor. This allows the rotation speed of tank 11 to be adjusted according to the movement of the particles in tank 11, thereby reducing the likelihood of particles colliding with the sides of tank 11 and causing collapse or deformation. In other words, it is possible to accurately reproduce and measure the actual seawater conditions.

[0108] The artificial seawater generator 1 is equipped with a lighting device 4 that irradiates light onto the tank 11. The sensor 3 includes an optical sensor that optically measures the seawater in the tank 11. The control circuit 91 adjusts the brightness of the lighting device 4 or the sensitivity of the optical sensor if the measurement range of the optical sensor is exceeded. This allows the artificial seawater generator 1 to ensure that the optical sensor measures within the measurement range, thereby improving the measurement accuracy of the optical sensor.

[0109] The artificial seawater generator 1 includes a supply and drainage device 13 for supplying and draining seawater into and out of the tank 11. The sensor 3 includes a sensor that measures the physical or chemical state of the seawater in the tank 11. The control circuit 91 provides feedback control based on the measurement results from the sensor 3 so that the state of the seawater in the tank 11 approaches a set target value. As a result, the artificial seawater generator 1 can bring the artificial seawater to the target state and accurately reproduce actual seawater.

[0110] The control circuit 91 controls the rotation speed of the tank 11 to be variable or to stop the rotation of the tank 11. This allows the artificial seawater generator 1 to apply impact to the particles contained in the artificial seawater in the tank 11. As a result, the artificial seawater generator 1 can measure the disintegration and deformation of the particles contained in the artificial seawater in the tank 11.

[0111] Sensor 3 includes an optical sensor that optically measures the inside of tank 11. The optical sensor measures particles inside tank 11 during the process of varying the rotation speed of tank 11 or when the rotation of tank 11 is stopped. This allows the artificial seawater generator 1 to measure the disintegration and deformation of particles contained in the artificial seawater inside tank 11.

[0112] The artificial seawater generator 1 includes a water supply and drainage device 13 for supplying and draining seawater into the tank 11. The control circuit 91 generates a water flow within the tank 11 by supplying and draining seawater into the tank 11. As a result, the artificial seawater generator 1 can apply impact to the particles contained in the artificial seawater in the tank 11 through the supply and drainage. Therefore, the artificial seawater generator 1 can measure the disintegration and deformation of the particles contained in the artificial seawater in the tank 11.

[0113] Sensor 3 includes an optical sensor that optically measures the inside of tank 11. The optical sensor measures particles inside tank 11 during the process of supplying and draining seawater into and out of tank 11. This allows the artificial seawater generator 1 to measure the disintegration and deformation of particles contained in the artificial seawater inside tank 11.

[0114] The artificial seawater generator 1 includes a supply and drainage device 13 for supplying and draining seawater into the tank 11. The supply and drainage device 13 can supply specific substances into the tank 11. This makes it possible to supply, for example, food for zooplankton into the tank 11, thereby reproducing actual seawater with greater accuracy.

[0115] The side of the tank 11 is provided with a sealing member 26 that allows the tank 11 to be opened. This allows for easy access to the inside of the tank 11, for example, to remove seawater from the tank 11 or to put substances into the tank 11.

[0116] The outer surface of the tank 11 is coated with an anti-reflective coating. This reduces the amount of light emitted from the lighting device 4 that is reflected off the outer surface of the tank 11 in the artificial seawater generation device 1.

[0117] The inner surface of the tank 11 is coated with fluorine. This reduces the amount of particles adhering to the inner surface of the tank 11 in the artificial seawater generator 1.

[0118] <4. This Technology> This technology can also be configured as follows: (1) An artificial seawater generating device comprising: a cylindrical tank for storing seawater inside; a roller base for supporting the tank so as to be rotatable in the circumferential direction; a sensor for measuring the state of the seawater in the tank; and a control circuit for controlling the operation of the tank. (2) The artificial seawater generating device according to (1), wherein the side surface of the tank is made of a transparent material around its entire circumference. (3) The artificial seawater generating device according to (2), further comprising an illumination device that irradiates sheet-like light from the side surface of the tank, and the sensor being an optical sensor that optically measures a predetermined range of seawater in the tank irradiated by the illumination device. (4) The artificial seawater generating device according to any one of (1) to (3), wherein the control circuit controls the rotation speed of the tank according to the settling speed of particles in the tank. (5) The artificial seawater generating apparatus according to (4), wherein the sensor includes an optical sensor for optically measuring the seawater in the tank, and the control circuit provides feedback control of the rotation speed of the tank according to the settling velocity of the particles measured by the optical sensor. (6) The artificial seawater generating apparatus according to any one of (1) to (5), comprising a lighting device for irradiating the tank with light, wherein the sensor includes an optical sensor for optically measuring the seawater in the tank, and the control circuit adjusts the brightness of the lighting device or the sensitivity of the optical sensor if it exceeds the measurement range of the optical sensor. (7) The artificial seawater generating apparatus according to any one of (1) to (6), comprising a water supply and drainage device for supplying and draining seawater into the tank, wherein the sensor includes a sensor for measuring the physical or chemical state of the liquid in the tank, and the control circuit provides feedback control based on the measurement results from the sensor so that the state of the seawater in the tank approaches a set target value. (8) The control circuit controls the rotation speed of the tank to be variable or to stop the rotation of the tank, the artificial seawater generating apparatus according to any one of (1) to (7).(9) The artificial seawater generating apparatus according to (8), wherein the sensor includes an optical sensor for optically measuring the inside of the tank, and the optical sensor measures particles in the tank during the process of the rotation speed of the tank being variable or the rotation of the tank being stopped. (10) The artificial seawater generating apparatus according to any one of (1) to (9), comprising a supply and drainage device for supplying and draining seawater into the tank, wherein the control circuit generates a water flow in the tank by supplying and draining seawater into the tank. (11) The artificial seawater generating apparatus according to (10), wherein the sensor includes an optical sensor for optically measuring the inside of the tank, and the optical sensor measures particles in the tank during the process of supplying and draining seawater into the tank. (12) The artificial seawater generating apparatus according to any one of (1) to (11), comprising a supply and drainage device for supplying and draining seawater into the tank, wherein the supply and drainage device is capable of supplying a specific liquid into the tank. (13) The artificial seawater generating apparatus according to any one of (1) to (12), wherein the side surface of the tank is provided with a sealing member that allows the tank to be opened. (14) The artificial seawater generating apparatus according to any one of (1) to (13), wherein the outer surface of the tank is coated with an anti-reflective coating. (15) The artificial seawater generating apparatus according to any one of (1) to (14), wherein the inner surface of the tank is coated with a fluorine coating.

[0119] 1. Artificial seawater generator 2. Artificial seawater generator 3. Sensor 4. Lighting device 5. Control device 6. Water quality control device 11. Tank 12. Roller stand 13. Water supply and drainage device

Claims

1. An artificial seawater generating device comprising: a cylindrical tank for storing seawater inside; a roller base for supporting the tank so that it can rotate in the circumferential direction; a sensor for measuring the state of the seawater inside the tank; and a control circuit for controlling the operation of the tank.

2. The artificial seawater generating apparatus according to claim 1, wherein the side surface of the tank is made of a transparent material around its entire circumference.

3. The artificial seawater generating apparatus according to claim 2, comprising an illumination device that irradiates a sheet-like light from the side of the tank, and the sensor comprising an optical sensor that optically measures a predetermined range of seawater in the tank irradiated by the illumination device.

4. The artificial seawater generating apparatus according to claim 1, wherein the control circuit controls the rotation speed of the tank according to the settling speed of the particles in the tank.

5. The artificial seawater generating apparatus according to claim 4, wherein the sensor includes an optical sensor for optically measuring seawater in the tank, and the control circuit provides feedback control of the rotation speed of the tank according to the settling velocity of the particles measured by the optical sensor.

6. An artificial seawater generating apparatus according to claim 1, comprising a lighting device that irradiates light onto the tank, wherein the sensor includes an optical sensor that optically measures the seawater in the tank, and the control circuit adjusts the brightness of the lighting device or the sensitivity of the optical sensor if the measurement range of the optical sensor is exceeded.

7. An artificial seawater generating apparatus according to claim 1, comprising a supply and drainage device for supplying and draining seawater into the tank, wherein the sensor includes a sensor for measuring the physical or chemical state of the liquid in the tank, and the control circuit provides feedback control based on the measurement results from the sensor so that the state of the seawater in the tank approaches a set target value.

8. The artificial seawater generating apparatus according to claim 1, wherein the control circuit controls the rotation speed of the tank to be variable or to stop the rotation of the tank.

9. The artificial seawater generating apparatus according to claim 8, wherein the sensor includes an optical sensor for optically measuring the inside of the tank, and the optical sensor measures particles inside the tank during the process in which the rotation speed of the tank is variable or the rotation of the tank is stopped.

10. An artificial seawater generating apparatus according to claim 1, comprising a supply and drainage device for supplying and draining seawater into the tank, wherein the control circuit generates a water flow in the tank by supplying and draining seawater into the tank.

11. The artificial seawater generating apparatus according to claim 10, wherein the sensor includes an optical sensor for optically measuring the inside of the tank, and the optical sensor measures particles in the tank during the process of supplying and draining seawater into the tank.

12. An artificial seawater generating apparatus according to claim 1, comprising a supply and drainage device for supplying and draining seawater into the tank, wherein the supply and drainage device is capable of supplying a specific liquid into the tank.

13. The artificial seawater generating apparatus according to claim 1, further comprising a sealing member on the side of the tank that allows the tank to be opened.

14. The artificial seawater generating apparatus according to claim 1, wherein the outer surface of the tank is coated with an anti-reflective coating.

15. The artificial seawater generating apparatus according to claim 1, wherein the inner surface of the tank is coated with fluorine.

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