Algae cultivation method, algae production method, and algae cultivation system

Abstract

To provide an algae cultivation method that can remove dirt adhering to the inner surface of a cultivation tank. [Solution] The algae cultivation method involves photographing the side of a cylindrical algae cultivation bag 40, in which algae are being cultivated, from the outside of the algae cultivation bag 40, and detecting any attached material on the inner surface of the algae cultivation bag 40 based on the captured image. The algae cultivation system comprises an algae cultivation bag 40, a computer 50, and a camera 46. The algae cultivation bag 40 is cylindrical and is used for culturing algae. The computer 50 causes the camera 46 to photograph the algae cultivation bag 40 during cultivation, acquires image data from the camera 46, and detects any attached material on the inner surface of the algae cultivation bag 40 based on the image data.

Description

Technical Field

[0001] The present invention relates to an algae cultivation method, an algae production method, and an algae cultivation system.

Background Art

[0002] An algae cultivation reactor in which a plurality of vertically long cultivation tanks are connected has been proposed (Patent Document 1). The cultivation tank has an outer tube made of glass and an inner tube made of resin, and an algae culture solution or the like is circulated inside the inner tube to cultivate algae. Since the inner tube can be appropriately replaced when dirt such as adhesion of algae to the inner surface occurs, maintenance of the cultivation tank is easy.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the algae cultivation reactor disclosed in Patent Document 1, dirt adhering to the inner surface of the cultivation tank cannot be removed.

[0005] On one side, it aims to provide an algae cultivation method or the like that can remove dirt adhering to the inner surface of the cultivation tank.

Means for Solving the Problems

[0006] The algae cultivation method photographs the side surface of a cylindrical algae cultivation bag in which algae are being cultivated from the outside of the algae cultivation bag, and detects deposits adhering to the inner surface of the algae cultivation bag based on the photographed image.

Effects of the Invention

[0007] On one side, it is possible to provide an algae cultivation method or the like that can remove dirt adhering to the inner surface of the cultivation tank. [Brief explanation of the drawing]

[0008] [Figure 1] This is an explanatory diagram illustrating the general process of cultivating and utilizing algae. [Figure 2] This is an explanatory diagram illustrating the configuration of an algae cultivation apparatus. [Figure 3] This is a front view of an algae cultivation apparatus. [Figure 4] Figure 3 is a cross-sectional view taken along the line IV-IV. [Figure 5] This is an explanatory diagram from Figure 4 with the algae culture bag and water container removed. [Figure 6] This is an explanatory diagram illustrating the configuration of an algae cultivation system. [Figure 7] This is an explanatory diagram illustrating the record layout of the log database. [Figure 8] This is a flowchart that explains the processing flow of a program. [Figure 9] This is an explanatory diagram illustrating the installation state of the algae cultivation apparatus according to Embodiment 2. [Figure 10] This is a perspective view of the algae cultivation apparatus according to Embodiment 2. [Figure 11] This is a cross-sectional view of the algae cultivation apparatus of Embodiment 2, taken horizontally. [Figure 12] This is an explanatory diagram illustrating the configuration of the algae cultivation system according to Embodiment 3. [Figure 13] This is an explanatory diagram illustrating the configuration of the algae cultivation system according to Embodiment 4. [Modes for carrying out the invention]

[0009] [Embodiment 1] Algae are a general term for organisms that perform oxygen-evolving photosynthesis, excluding land plants, and their closely related species. Taxonomically, they are divided into various lineages. A wide variety of algae with diverse properties have been discovered, including several species that produce and store substances useful to humans.

[0010] For example, there are known intracellular oil-producing algae that produce oil through photosynthesis and accumulate it within the cells. From the intracellular oil-producing algae cultured using an algae culture device, the oil stored within the cells can be collected. The collected oil can be utilized as raw materials such as jet fuel and diesel fuel.

[0011] The energy obtained from the fuel produced by intracellular oil-producing algae is a type of renewable energy. That is, by increasing the amount of fuel produced from intracellular oil-producing algae, the proportion of methods using renewable energy among the ways of generating energy can be increased.

[0012] By making it possible to install the algae culture device in various locations, even in developing countries, particularly the least developed countries, small island countries, and landlocked countries, etc., fuel can be produced at a relatively low cost. Therefore, the algae culture device that can be installed in various locations contributes to enabling all people to continuously use inexpensive, safe, and modern energy.

[0013] By using the fuel produced by intracellular oil-producing algae instead of extracting and using fossil fuels from underground, carbon dioxide emissions can be reduced. Here, intracellular oil-producing algae are algae that produce fuel using, for example, carbon dioxide emitted by humans into the atmosphere or carbon dioxide already present in the atmosphere. Therefore, the fuel produced by intracellular oil-producing algae is a sustainable fuel, and promoting the use of intracellular oil-producing algae can contribute to slowing down the speed of climate change caused by greenhouse gases.

[0014] Algae, like ordinary plants, can also be processed into food. Algae include seaweeds that have been conventionally familiar as foods, such as wakame, kelp, and sea grapes. There are also algae such as chlorella and euglena that are used for various purposes such as cosmetics and pharmaceuticals in addition to health foods.

[0015] By producing food using an algae cultivation device, planned production of food becomes possible. Therefore, it is possible to prevent food from being discarded or lost due to sudden fluctuations in production volume. As described above, it can contribute to the sustainable management and efficient use of natural resources.

[0016] For example, algae that produce useful organic substances such as ferrocyanine or astaxanthin are also known. By culturing and utilizing such types of algae using a cultivation device, it can contribute to minimizing the adverse effects on the natural environment when producing these useful organic substances.

[0017] The cultivation device that can be installed in various locations can be used even in, for example, countries with the most delayed development, African countries, small developing island countries, and landlocked developing countries. Therefore, by manufacturing useful organic substances such as ferrocyanine or astaxanthin using the cultivation device, for example, it can contribute to increasing income in these countries and regions and reducing inequality around the world.

[0018] FIG. 1 is an explanatory diagram for explaining an outline of a process of culturing and utilizing algae. An algae cultivation bag 40 is attached to an algae cultivation device 10. The algae cultivation bag 40 is cylindrical, and a connection base 42 is provided at the first end. The second end of the algae cultivation bag 40 is sealed. The algae cultivation bag 40 bulges into a cylindrical shape having a substantially rectangular cross-section when filled with contents. Details of the configurations of the algae cultivation device 10 and the algae cultivation bag 40 will be described later. Note that all the processes described below are carried out during the cultivation of algae in the algae cultivation bag 40.

[0019] After the amount of algae in the algae cultivation bag 40 has sufficiently grown, the algae in the algae cultivation bag 40 are collected by a collection vehicle 18. At the time of collection, for example, about 50 percent of the contents in the algae cultivation bag 40 are collected, and the remaining about 50 percent are left in the algae cultivation bag 40. A culture solution is added to the algae cultivation bag 40 by the algae cultivation device 10, and the cultivation continues.

[0020] The collection vehicle 18 transports the collected algae to a processing plant and loads them into a material tank 19. At the processing plant, the algae are separated from the culture medium by a filter, the algae are dried, and the products are purified to obtain the products. From these products, for example, fuel, food, or pigments are manufactured.

[0021] Furthermore, when collecting some of the contents of the algae culture bag 40 into the collection vehicle 18, a filter may be used to remove some or all of the culture solution. By collecting the algae into the collection vehicle 18 with a higher density of algae, transportation costs when transporting the algae to the processing plant can be reduced.

[0022] If cultivation is continued for a long period, algae will adhere to the inner surface of the algae culture bag 40. The attached algae tend to form a biofilm, which is an aggregate of microorganisms including bacteria in addition to algae. Because the biofilm has a slimy texture due to secretions from the microorganisms, it is difficult to peel off from the inner surface of the algae culture bag 40.

[0023] Even if microorganisms in the biofilm die, they remain inside the biofilm, held in place by the slime. Since the dead microorganisms become a nutrient source for other microorganisms, the biofilm expands. As a result, the inner surface of the algae culture bag 40 is covered with living microorganisms, the remains of dead microorganisms, and attached substances including secretions from the microorganisms.

[0024] The attached organisms block light, thus hindering the growth and proliferation of algae floating in the culture medium. By applying the vibrator 38 (see Figure 2) to the outer surface of the algae culture bag 40, the attached organisms can be detached from the inner surface of the algae culture bag 40. The vibrator 38 is a device that generates ultrasonic vibrations of, for example, several megahertz.

[0025] For the vibration device 38, for example, a commercially available ultrasonic facial massager can be used. Ultrasonic facial massagers are small, lightweight, and easy to handle. By having the worker gently stroke the outer surface of the algae culture bag 40 with the vibrating part of the ultrasonic facial massager, the internal deposits can be removed without damaging the algae culture bag 40. In the following description, the process of removing the internal deposits of the algae culture bag 40 will be referred to as cleaning.

[0026] Furthermore, when using the vibration device 38, it is desirable for the operator to wet the surface of the algae culture bag 40 with water. By ensuring that there is no air layer between the vibration device 38 and the algae culture bag 40, the operator can efficiently transmit the ultrasonic vibrations generated by the vibration device 38 to the algae culture bag 40.

[0027] By using a small vibrator 38 that can be held and used by the operator with one hand, the algae culture bag 40 can be cleaned with significantly less energy compared to, for example, vibrating the entire algae culture apparatus 10.

[0028] The vibrating device 38 may be an ultrasonic vibrating device newly designed for cleaning the algae culture bag 40. The vibrating device 38 may also be a low-frequency vibrating device. For example, using a vibrating device 38 equipped with a vibrating part that matches the shape of the algae culture bag 40 filled with culture medium improves the work efficiency of the operator.

[0029] Figure 2 is an explanatory diagram illustrating the configuration of the algae cultivation apparatus 10. Figure 2 schematically shows the configuration of the algae cultivation apparatus 10. Figure 3 is a front view of the algae cultivation apparatus 10. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 3. Figure 5 is an explanatory diagram obtained by removing the algae cultivation bag 40 and water container 47 from Figure 4.

[0030] As shown in Figure 2, the algae cultivation apparatus 10 comprises a cultivation case 20, a control device 50, a perfusion device 35, and a pump 48. As shown in Figures 3 and 4, the cultivation case 20 comprises a roughly U-shaped outer frame 25, a top plate 27, and a heat transfer plate 23. The outer frame 25 comprises a roughly rectangular bottom plate 22 and two roughly rectangular side walls 24 that protrude in the same direction from two non-adjacent sides of the bottom plate 22.

[0031] The heat transfer plate 23 is rectangular in shape and is sandwiched between the sides of the two side walls 24, positioned parallel to the bottom plate 22. In the following description, of the two surfaces of the heat transfer plate 23, the surface exposed to the outside will be referred to as the first surface, and the surface facing the bottom plate 22 will be referred to as the second surface. The first surface is preferably a light-reflecting surface that reflects light transmitted through the algae culture bag 40 back towards the algae culture bag 40.

[0032] The top plate 27 is rectangular in shape and is positioned to cover one end of the outer frame 25. The perfusion device 35 is roughly rectangular in shape and is positioned to cover the other end of the outer frame 25. The outer frame 25, the heat transfer plate 23, the top plate 27, and the perfusion device 35 form the cooling chamber 32 shown in Figure 5.

[0033] As shown in Figure 4, a water container 47 is housed in the cooling chamber 32. The water container 47 is a strong and flexible resin bag. As shown in Figure 4, the second surface of the heat transfer plate 23 is in close contact with the water container 47. If the cooling chamber 32 is watertight, the cooling chamber 32 itself may also serve as the water container 47.

[0034] The volume of the water container 47 should preferably be greater than the sum of the volumes of the algae culture bags 40. Specifically, as shown in Figure 4, the thickness T1 of the five algae culture bags 40 is thinner than the thickness T2 of the water container 47. For example, T1 is about 100 millimeters and T2 is about 200 millimeters. Therefore, the volume of the water container 47 is about twice the sum of the volumes of the algae culture bags 40.

[0035] By setting T1 to approximately 100 millimeters, sufficient light for photosynthesis is irradiated to all algae in the algae culture bag 40. The reason why it is desirable for the volume of the water container 47 to be greater than the total volume of the algae culture bags 40 will be explained later.

[0036] As shown in Figure 3, five roughly cylindrical hangers 26 protrude from the first surface of the heat transfer plate 23. Algae culture bags 40 are attached to each hanger 26 parallel to each other. The five algae culture bags 40 are arranged in a single row. The algae culture bags 40 are strong and flexible resin bags. The sides of the algae culture bags 40 are in close contact with the first surface of the heat transfer plate 23.

[0037] A pipe-shaped supply tube 41 is placed inside the algae culture bag 40. One end of the supply tube 41 is attached to a connector 42. The other end of the supply tube 41 is located near the end of the algae culture bag 40 that is farther from the connector 42. The inside of the algae culture bag 40 is filled with algae and culture medium. The algae culture bag 40 is positioned so that the connector 42 side, i.e., the first end side, is lower.

[0038] Perfusion tubes 36 are connected to the perfusion device 35. The connection fittings 42 of each algae culture bag 40 are connected to the perfusion tubes 36. The perfusion device 35 includes a filter, a culture solution tank, a carbon dioxide supply, and a nutrient supply (not shown), and perfuses the culture solution while maintaining it in a good condition suitable for algae cultivation.

[0039] Sensors 45, such as temperature sensors, light sensors, color sensors, or pH (Potential Hydrogen) sensors, are placed at various locations in the algae cultivation apparatus 10. The water container 47 is connected to the pump 48. The perfusion apparatus 35, sensors 45, and pump 48 are connected to the control device 50 by wire or wireless means.

[0040] Camera 46 is positioned to photograph the algae culture bag 40. Camera 46 is fixed to, for example, the culture case 20. Camera 46 may also function as a security camera. Camera 46 is connected to the control device 50 by wire or wireless. Camera 46 may also be connected to the control device 50 via a security camera control device (not shown). The configuration of the control device 50 will be described later.

[0041] The number of algae culture bags 40 is not limited to five. The algae culture apparatus 10 may have any number of algae culture bags 40, from one to four, or from six to six.

[0042] It is desirable that the algae cultivation device 10 be positioned so that sunlight shines well on the sides of the algae cultivation bag 40. Let's explain using the example of installing the algae cultivation device 10 in the Northern Hemisphere. It is desirable that the algae cultivation device 10 be positioned at an angle approximately equal to the latitude of the installation location, tilted southward relative to the horizontal plane. For example, a mounting frame for solar power generation panels can be repurposed as a mounting frame for the algae cultivation device 10.

[0043] Figure 6 is an explanatory diagram illustrating the configuration of the algae cultivation system 12. The algae cultivation system 12 includes a server 80 in addition to the aforementioned algae cultivation apparatus 10. Each control device 50 included in the multiple algae cultivation apparatuses 10 and the server 80 are connected via a network.

[0044] The control device 50 comprises a control unit 51, a main memory 52, an auxiliary memory 53, a communication unit 54, a display unit 55, an input unit 56, and a bus. The control unit 51 is an arithmetic control device that executes the program of this embodiment. One or more CPUs (Central Processing Units), GPUs (Graphics Processing Units), or multi-core CPUs are used in the control unit 51. The control unit 51 is connected to each hardware component of the control device 50 via the bus.

[0045] The main memory 52 is a storage device such as SRAM (Static Random Access Memory), DRAM (Dynamic Random Access Memory), or flash memory. The main memory 52 temporarily stores information necessary during processing performed by the control unit 51 and the program currently being executed by the control unit 51.

[0046] The auxiliary storage device 53 is a storage device such as SRAM, flash memory, hard disk, or magnetic tape. The auxiliary storage device 53 stores the program to be executed by the control unit 51 and various data necessary for the execution of the program. The communication unit 54 is an interface for communication between the control device 50 and a network or other devices.

[0047] The display unit 55 is, for example, a liquid crystal display device or an organic EL (Electro-Luminescence) display device. The input unit 56 is, for example, an input device such as a keyboard, mouse, trackball, microphone, or card reader. The display unit 55 and the input unit 56 may be stacked together to form a touch panel.

[0048] The display unit 55 may be a connection interface that connects the control device 50 to an external display device. A communication unit 54 that connects data to an external display device via a network may implement the functions of the display unit 55 and the input unit 56.

[0049] The perfusion device 35, sensor 45, camera 46, and pump 48 are connected to the control device 50 via an interface such as USB (Universal Serial Bus) or Bluetooth®. The perfusion device 35, sensor 45, camera 46, and pump 48 may also be connected to the control device 50 via a network. The control unit 51 receives data from the sensor 45 and images from the camera 46 and controls the perfusion device 35 and pump 48. The control unit 51 transmits data regarding the cleaning of the algae culture bag 40 to the server 80, as will be described later.

[0050] The control device 50 is, for example, a single-board computer or single-chip computer that integrates a processor, memory, and various input / output interfaces. The control device 50 may also be a general-purpose information device such as a personal computer, smartphone, or tablet.

[0051] The control device 50 may consist of two control devices: a first control device to which the perfusion device 35, sensor 45, and pump 48 are connected, and a second control device to which the camera 46 is connected. Specifically, the first control device is a circuit board that performs PID (Proportional-Integral-Differential) control of the perfusion device 35 and pump 48, and the second control device may be a general-purpose information device such as a personal computer, smartphone, or tablet. If the camera 46 also functions as a security camera, the control unit of the security system may also function as the second control device.

[0052] The server 80 comprises a control unit 81, main memory 82, auxiliary memory 83, communication unit 84, and a bus. The control unit 81 is an arithmetic control device that executes the program of this embodiment. One or more CPUs, GPUs, or multi-core CPUs are used in the control unit 81. The control unit 81 is connected to each hardware component of the server 80 via the bus.

[0053] The main memory 82 is a storage device such as SRAM, DRAM, or flash memory. The main memory 82 temporarily stores information necessary during processing performed by the control unit 81 and the program currently being executed by the control unit 81.

[0054] The auxiliary storage device 83 is a storage device such as SRAM, flash memory, hard disk, or magnetic tape. The auxiliary storage device 83 stores the program to be executed by the control unit 81 and various data necessary for the execution of the program. The communication unit 84 is an interface for communication between the server 80 and the network or other devices.

[0055] Server 80 is a mainframe computer, a virtual machine running on a mainframe computer, multiple personal computers performing distributed processing, or a cloud computing system. Server 80 may also be a general-purpose personal computer or information device such as a tablet. If the number of algae cultivation devices 10 to be managed is small, the control device 50 may also serve as Server 80.

[0056] Figure 7 is an explanatory diagram illustrating the record layout of the log DB 65. The log DB 65 is a database that records the device ID (Identifier) ​​uniquely assigned to the algae culture apparatus 10, the image and date and time when the control unit 51 determined that the algae culture bag 40 needed cleaning, the date and time when the algae culture bag 40 was cleaned, and the image taken after cleaning, in association with each other.

[0057] The log DB65 includes a device ID field, a date and time of capture field, a judgment image field, a cleaning date and time field, and a post-cleaning image field. The device ID field records the device ID uniquely assigned to the algae culture device 10 that has been determined to require cleaning. The date and time of capture field and the judgment image field record the date and time when the image was captured and the control unit 51 determined, by a program described later, that the algae culture bag 40 needed cleaning, as well as the image data, respectively.

[0058] The cleaning date and time field records the date and time when the worker cleaned the algae culture bag 40. The post-cleaning photo field records the image taken after the cleaning was completed. The date and time recorded in the cleaning date and time field may be the date and time when the image was taken after the cleaning was completed, or the date and time when the server 80 received the image, etc.

[0059] A blank entry in the Cleaning Date and Time field indicates that cleaning has not yet been performed. A blank entry in the Post-Cleaning Image field indicates that server 80 has not yet received a post-cleaning image.

[0060] The operation of the algae cultivation system 12 is outlined below. An algae cultivation bag 40 containing a small amount of algae and culture medium is attached to a suspension device 26. A connecting nozzle 42 is connected to a perfusion tube 36. The culture medium is perfused by a perfusion device 35. The culture medium is supplied from the perfusion device 35 to a supply tube 41 via the connecting nozzle 42, and then supplied into the algae cultivation bag 40 from the upper end of the supply tube 41.

[0061] A filter (not shown) is placed in the connection port 42. The culture medium at the bottom of the algae culture bag 40 returns to the perfusion tube 36 via the filter. At this time, the algae do not pass through the filter and remain in the algae culture bag 40. Therefore, only culture medium without algae circulates in the perfusion tube 36. Note that the filter can be omitted when culturing the same algae in connected algae culture bags 40.

[0062] At night, the water in the water container 47 is drained by the pump 48 and replaced with fresh groundwater. The groundwater maintains a constant temperature throughout the year. Therefore, in the summer, the algae culture bags 40 are cooled by the groundwater via the heat transfer plate 23. In the winter, the algae culture bags 40 are warmed by the groundwater via the heat transfer plate 23, preventing freezing. Because the volume of the water container 47 is greater than the total volume of the algae culture bags 40, the water container 47 effectively maintains the temperature of the algae culture bags 40 for extended periods.

[0063] If replacing the groundwater once at night is insufficient to maintain the temperature of the algae culture bag 40 at a temperature suitable for cultivation or for the survival of algae, the groundwater in the water container 47 may be replaced multiple times a day.

[0064] The time period during which the groundwater in the water container 47 is replaced is not limited to nighttime. For example, the control unit 51 may operate the pump 48 to replace the groundwater in the water container 47 when appropriate conditions are met, such as when the temperature of the water container 47 detected by the sensor 45 exceeds a predetermined standard value. The standard value is predetermined, for example, according to the season or outside temperature. An operator who manages the state of the algae cultivation apparatus 10 may also perform the operation to replace the groundwater in the water container 47 based on a comprehensive judgment of the climate, the growth status of the algae, and the algae production plan.

[0065] The standard value may be determined based on the difference between the temperature of the water container 47 and the temperature of the fresh groundwater. If the temperature of the water container 47 hardly changes, the algae cultivation device 10 can be provided that reduces the energy consumption of the pump 48 and the amount of groundwater pumped up by not replacing the groundwater. The groundwater in the water container 47 may be replaced little by little at all times. The algae cultivation device 10 can be provided that has little temperature change in the water container 47.

[0066] As explained above, groundwater is preferable for the water placed in the water container 47. However, if tap water, drain water, or water that has undergone heat exchange with the exhaust heat of an air conditioner can be obtained, which have the same effect as groundwater in maintaining the temperature of the algae culture bag 40, then these waters may also be used.

[0067] The algae cultivation apparatus 10 may have a cooling device or a heating device for use on extremely hot or cold days. The temperature of the algae cultivation bag 40 is detected by a sensor 45.

[0068] Based on the algal cultivation status or the state of the culture medium detected by the sensor 45, the concentration of the culture medium or the concentration of carbon dioxide may be automatically adjusted. In this way, algae are cultivated inside the algal cultivation bag 40.

[0069] The camera 46 periodically captures images of the algae culture bag 40, and these images are sent to the control device 50. Images are captured approximately once a day or once every few days. The capture time is pre-set to ensure that reflected light from the algae culture bag 40 does not directly enter the camera 46, allowing for the capture of clear photographs.

[0070] The imaging range may be set to capture the entire algae culture bag 40 attached to the algae culture apparatus 10, or it may be set to magnify and photograph areas where fouling is particularly likely to occur. Specifically, it has been experimentally shown that fouling is likely to occur at the bottom of the algae culture bag 40, that is, near the connection port 42.

[0071] If a security camera is used as camera 46, for example, the security camera's control device selects an appropriate image and transmits it to the control device 50. Images captured by the security camera may be transmitted to the control device 50 in real time, and the control unit 51 may extract the images to be used.

[0072] The control unit 51 analyzes the image captured by the camera 46 to detect areas where attached organisms are visible and determines whether or not the algae culture bag 40 needs to be cleaned. For example, the control unit 51 determines the area occupied by the attached organisms through image processing. This area corresponds to the amount of attached organisms. The control unit 51 determines that cleaning is required if the area occupied by the attached organisms exceeds a predetermined threshold, that is, if the amount of attached organisms exceeds a predetermined threshold.

[0073] This will be explained in detail using the example of a type of algae that produces deposits with a color close to Kariyasu yellow being cultivated in the algae culture bag 40. Note that depending on the type of algae, deposits with a color significantly different from Kariyasu yellow may be produced. The control unit 51 acquires the number of pixels with a color close to Kariyasu yellow, i.e., pixels in which deposits are photographed. Kariyasu yellow is one of the conventional colors defined in JIS (Japanese Industrial Standards) Z8102 "Color Names of Object Colors," and is "a light greenish yellow." The control unit 51 determines that cleaning is required if the number of pixels with a color close to Kariyasu yellow exceeds a predetermined threshold.

[0074] The threshold for determining whether cleaning is necessary is set appropriately by the manager of the algae cultivation system 12 or the manager of each individual algae cultivation device 10, taking into consideration the climate of the location where the algae cultivation device 10 is installed, the number of personnel performing the cleaning work, and the time required for the personnel to travel to the algae cultivation device 10.

[0075] For example, for algae cultivation apparatus 10 located in an inconvenient location, requiring a long travel time for the operator, the manager sets a lower threshold. Even if the period between receiving notification and the operator performing cleaning is somewhat long, it will not significantly hinder algae growth, allowing for smoother scheduling of the operator.

[0076] The control unit 51 may input the image captured by the camera 46 to a learning model that receives an image and outputs whether cleaning is necessary, and obtain a determination result regarding whether cleaning is necessary. The learning model is generated by supervised machine learning using, for example, a CNN (Convolutional Neural Network) neural network structure.

[0077] The training data used for supervised machine learning consists of multiple sets of images taken by camera 46 and data indicating whether cleaning is necessary or not. Alternatively, the training data may consist of multiple sets of images taken by camera 46 and markings indicating the location of attached objects.

[0078] Examples of CNNs that can be used to generate the learning models usable in this embodiment include R-CNN (Region Based Convolutional Neural Network), YOLO (You Only Look Once), U-Net, and GAN (Generative Adversarial Network). The learning models may also be generated using neural network structures other than CNNs.

[0079] The control unit 51 may further process the results output by the learning model to determine whether cleaning is necessary. Specifically, the control unit 51 inputs the image captured by the camera 46 into a learning model trained by machine learning to accept the image and classify the parts with attached substances from the other parts, and obtains information about the classification results. The control unit 51 determines that cleaning is necessary if the area of ​​the parts with attached substances exceeds a predetermined threshold.

[0080] If the control unit 51 determines that cleaning is required, it sends a notification to, for example, the person in charge of managing the algae cultivation apparatus 10. The notification may be sent via email, SMS (Short Message Service), or a pop-up notification on the management screen. Based on the instructions of the person in charge of management, the worker goes to the installation location of the algae cultivation apparatus 10 and cleans the surface of each algae cultivation bag 40 by applying the vibrator 38 to it.

[0081] The control unit 51 may transmit the images captured by the camera 46 to the supervisor or the operator. The supervisor or operator can visually inspect the images to determine the presence and amount of attached material and decide whether cleaning is necessary.

[0082] The control unit 51 may evaluate the amount of attached material by dividing it into, for example, five attachment levels, and include information about the attachment level in the notification. If a large number of notifications occur at once, the manager can prioritize assigning workers to algae cultivation devices 10 with high attachment levels, i.e., a large amount of attached material.

[0083] The operator operates a cleaning completion switch, for example, located near the algae cultivation apparatus 10. Based on the operation of the cleaning completion switch, the camera 46 photographs the algae cultivation bag 40 and transmits the image and a cleaning completion notification to the control device 50. In other words, the operator operating the cleaning completion switch means that the operator instructs the camera 46 to photograph the algae cultivation bag 40 and transmit the image data to the control device 50.

[0084] The control unit 51 associates the received image data with the date and time of capture or the date and time of reception and temporarily stores it in the main memory 52 or auxiliary memory 53. The control unit 51 transmits the device ID of the algae culture apparatus 10, the date and time of capture, and the image after cleaning to the server 80 via the network. The server 80 extracts the corresponding record from the log DB 65 and records the data in the cleaning date and time field and the image after cleaning field. The IP address or MAC address assigned to the control unit 51 may also serve as the device ID.

[0085] The worker may also take a picture of the cleaned algae culture bag 40 with their smartphone or other device and send it to the control device 50. Communication from the smartphone will replace the function of the cleaning completion switch.

[0086] The worker may take a picture of the cleaned algae culture bag 40 with their smartphone or other device and send it directly to the server 80. The control unit 81 can determine the location where the picture was taken and the device ID and date and time of the picture based on the EXIF ​​(Exchangeable Image File Format) data contained in the received image data.

[0087] Figure 8 is a flowchart illustrating the program's processing flow. The program in Figure 8 is activated, for example, once a day or once every few days, at a time suitable for photographing the algae culture bag 40. In parallel with the processing shown in Figure 8, the control unit 51 performs processes to maintain the culture, such as adjusting and circulating the culture medium.

[0088] The control unit 51 acquires an image of the algae culture bag 40 from the camera 46 (step S501). Based on the image, the control unit 51 determines whether the algae culture bag 40 needs to be cleaned (step S502). The control unit 51 may determine whether cleaning is necessary based on the number of pixels having a predetermined color, or it may determine whether cleaning is necessary using a learning model.

[0089] If it is determined that cleaning is required (YES in step S502), the control unit 51 sends a notification to the person in charge of managing the algae cultivation apparatus 10 (step S503). The control unit 51 sends the apparatus ID, the date and time the image used for the determination in step S502 was taken, and the image data in association with each other to the server 80 (step S504). If it is determined that cleaning is not required (NO in step S502), or after the completion of step S504, the control unit 51 terminates processing.

[0090] The control unit 81 receives data transmitted from the control device 50 (step S601). The control unit 81 creates new fields in the log DB 65 and records data in the device ID field, the shooting date and time field, and the judgment time image field, respectively (step S602).

[0091] When the cleaning completion switch is operated by the operator, the control unit 51 starts processing via interrupt processing. The control unit 51 acquires an image after cleaning is complete (step S511). The control unit 51 associates the device ID, the date and time the image was taken in step S511, and the image data and sends them to the server 80 (step S512). The control unit 51 then terminates processing.

[0092] The control unit 81 receives data transmitted from the control device 50 (step S611). The control unit 81 searches the log DB 65 using the received device ID as a key and extracts records. If multiple records are extracted, the control unit 81 selects the record with the most recent shooting date and time recorded in the shooting date and time record.

[0093] The control unit 81 records the date and time of shooting and the image data received in step S611 in the cleaning date and time field and the image after cleaning field of the extracted record, respectively (step S612).

[0094] Furthermore, the determination of whether cleaning is necessary in step S502 and the notification in step S503 may be performed by the control unit 81. Specifically, the control unit 51 transmits all images acquired in step S501 to the server 80, and the control unit 81 performs the processing in steps S502 and S503. This makes it possible to provide an algae cultivation apparatus 10 with a low load on the control device 50.

[0095] According to this embodiment, an algae cultivation device 10 can be provided that can remove dirt adhering to the inner surface of the algae cultivation bag 40. For example, even if the algae cultivation device 10 is installed in a location with poor transportation access and low land prices, a worker can be dispatched to the site when the amount of adhering material increases and cleaning becomes necessary, thus providing an algae cultivation device 10 with low running costs.

[0096] According to this embodiment, the algae culture bag 40 can be used continuously for a long period of time, thus providing an algae culture apparatus 10 that generates less waste. According to this embodiment, even if the amount of attached organisms fluctuates due to weather conditions, for example, the algae culture bag 40 can be cleaned at an appropriate time. Therefore, the yield of the algae culture apparatus 10 can be increased.

[0097] According to this embodiment, the log DB65 stores information such as photos before and after cleaning, as well as the date and time. The log DB65 can be used, for example, as training data for a learning model that accurately determines whether or not cleaning is necessary.

[0098] Furthermore, in step S502 of the program described using Figure 8, the control unit 51 may determine whether harvesting is necessary in addition to whether cleaning is necessary. For example, for an algae culture bag 40 in which green algae are being cultivated, the control unit 51 can determine whether harvesting is necessary based on the intensity of the green color. If it is notified that harvesting is necessary, the person in charge of managing the algae culture device 10 will arrange for collection by the collection vehicle 18. Even if the growth rate of algae fluctuates due to weather conditions, etc., the algae culture device 10 can be provided that allows harvesting at the appropriate time.

[0099] The solar panels may be connected to the algae cultivation apparatus 10 via a battery. Alternatively, instead of, or in conjunction with, the solar panels, an energy harvesting device that converts low-density energy such as ambient wind, vibration, and heat into electrical energy may be connected to the battery. This makes it possible to realize an algae cultivation apparatus 10 that operates on renewable energy.

[0100] The algae cultivation apparatus 10 may be connected to both a storage battery and a solar panel, and a commercial power supply. For example, if the power obtained from the solar panel is insufficient, power may be supplied from the commercial power supply.

[0101] [Embodiment 2] This embodiment relates to an algae cultivation apparatus 10 that can cultivate algae in urban areas such as next to buildings. Parts common to Embodiment 1 will not be described.

[0102] Figure 9 is an explanatory diagram illustrating the installation state of the algae cultivation apparatus 10 according to Embodiment 2. The algae cultivation apparatus 10, which is roughly rectangular in shape, is installed vertically around a building 70 such as an office building. The algae cultivation apparatus 10 is securely fixed to the ground, road surface, or floor surface of the building 70, for example, by anchor bolts (not shown), to prevent the risk of tipping over. The algae cultivation apparatus 10 is detachably fixed to a mooring device (not shown), and may be configured to be movable as needed.

[0103] Figure 10 is a perspective view of the algae culture apparatus 10 of Embodiment 2. Figure 11 is a cross-sectional view of the algae culture apparatus 10 of Embodiment 2, cut horizontally. A roughly rectangular plate-shaped culture case 20 is placed on a roughly rectangular perfusion device 35. The algae culture apparatus 10 of this embodiment is equipped with a light-transmitting plate 21.

[0104] The translucent plate 21 is a flat plate that is translucent and has approximately the same dimensions as the bottom plate 22. The translucent plate 21 is positioned to cover the opening of the outer frame 25. As shown in Figure 11, the algae culture bag 40 is sandwiched between the heat transfer plate 23 and the translucent plate 21. It is desirable that the top plate 27 is translucent, similar to the translucent plate 21.

[0105] One side of the light-transmitting plate 21 and one side wall 24 are attached by a hinge (not shown in the illustration). The worker opens the light-transmitting plate 21 like a single-leaf door to expose the algae culture bag 40, and then applies the vibrator 38 to the algae culture bag 40 to perform cleaning. The light-transmitting plate 21 may be divided into two parts, each attached to the side wall 24 by a hinge. The worker opens the light-transmitting plate 21 like a double-leaf door.

[0106] Furthermore, it is desirable that the translucent panel 21 be fitted with a lock (not shown in the illustration) to prevent it from being opened by passersby or other third parties.

[0107] Inside the algae cultivation device 10, for example, green algae are cultivated, giving passersby a sense of greenery, similar to typical street trees. For example, red or blue algae may also be cultivated. As part of environmental design, combinations of algae with colors that are pleasing to the eye of passersby may be cultivated inside the algae cultivation device 10.

[0108] The algae cultivation apparatus 10 may be installed, for example, in place of a fence surrounding a site. The algae cultivation apparatus 10 may be installed indoors in place of a partition. The algae cultivation apparatus 10 may be installed in various locations, for example, on the roof of a building 70, or on the median strip of a road.

[0109] The algae cultivation device 10 may be placed, for example, on the outside of a building 70, covering existing windows. It can deliver, for example, soft green light into the room while blocking the heat of direct sunlight, thereby improving cooling efficiency.

[0110] According to this embodiment, by providing a light-transmitting plate 21, an algae cultivation device 10 can be provided that can be installed in locations easily accessible to third parties. By installing the algae cultivation device 10 vertically, the algae cultivation device 10 can be installed even in urban areas where land is expensive.

[0111] [Embodiment 3] This embodiment relates to an algae cultivation system 12 in which an autonomous robot performs cleaning of algae cultivation bags 40 and harvesting of algae. Parts common to Embodiment 1 will not be described.

[0112] Figure 12 is an explanatory diagram illustrating the configuration of the algae cultivation system 12 of Embodiment 3. The algae cultivation system 12 of this embodiment includes a robot 16. The robot 16 is connected to a control device 50 and a server 80 via a network.

[0113] The robot 16 has a form suitable for autonomous movement around the location where the algae cultivation device 10 is installed, such as a humanoid form or a multi-legged walking form. The robot 16 is equipped with a manipulator 15, a harvesting tank 17, a vibrator 38, and a camera 46. The control unit, various sensors, and actuators that enable the autonomous operation of the robot 16 are not shown in the illustrations or given in description.

[0114] The robot 16 continuously or periodically patrols a large number of algae cultivation devices 10. The robot 16 takes a picture of the algae cultivation bag 40 and transmits the image to the control device 50. The control unit 51 determines whether the algae cultivation bag 40 needs to be cleaned based on the image. If it determines that cleaning is required, the control unit 51 notifies the robot 16.

[0115] Upon receiving a notification, the robot 16 uses the manipulator 15 to apply the vibrator 38 to the algae culture bag 40 to clean off any attached organisms. Alternatively, the control unit of the robot 16 may determine whether cleaning is necessary based on the image, instead of the control unit 51.

[0116] Whether or not to harvest the algae is determined based on the number of days elapsed since the last harvest or on images taken by camera 46. If harvesting is necessary, robot 16 uses manipulator 15 to connect the algae culture bag 40 to the harvest tank 17 and transfers, for example, about 50 percent of the algae in the algae culture bag 40 to the harvest tank 17. Before the harvest tank 17 becomes full, robot 16 autonomously moves to a larger tank or similar container and transfers the contents.

[0117] According to this embodiment, an algae cultivation system 12 is provided that can operate a large number of algae cultivation devices 10 unattended.

[0118] [Embodiment 4] Figure 13 is an explanatory diagram illustrating the configuration of the algae cultivation system 12 of Embodiment 4. This embodiment relates to a configuration in which the algae cultivation system 12 is realized by operating a general-purpose server computer 90 in combination with a program 97. Parts common to Embodiment 1 will not be explained.

[0119] The server computer 90 includes the aforementioned control unit 81, main memory 82, auxiliary memory 83, communication unit 84, and bus, as well as a read unit 89.

[0120] Program 97 is recorded on a portable recording medium 96. The control unit 81 reads Program 97 via the reading unit 89 and saves it to the auxiliary storage device 83. The control unit 81 may also read Program 97 stored in a semiconductor memory 98, such as flash memory, implemented in the server computer 90. Furthermore, the control unit 81 may download Program 97 from a server computer (not shown) connected via the communication unit 84 and a network (not shown) and save it to the auxiliary storage device 83.

[0121] Program 97 is installed as a control program for the server computer 90, loaded into the main memory 82, and executed. The control unit 81 transmits the portion of Program 97 that is executed by the control unit 51 to each control unit 50 via the network. The transmitted program is installed as a control program for the control unit 50, loaded into the control unit 51, and executed. Thus, the algae cultivation system 12 described in Embodiment 1 is realized.

[0122] The program is an example of a program product. The program may be provided on a recording medium or distributed from an external computer. Computer programs can be deployed to run on a single computer, at a single site, or distributed across multiple sites and interconnected by a communication network.

[0123] The technical features (constituent elements) described in each embodiment are combinable with each other, and by combining them, new technical features can be formed. The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims, not in the sense described above, and all modifications within the sense and scope equivalent to the claims are intended to be included.

[0124] The independent and dependent claims described in the claims can be combined with each other in any combination, regardless of the form of reference. Furthermore, while the claims use a multi-claim format in which claims refer to two or more other claims (multi-claim format), this is not the only option. Claims may also be described using a multi-claim format in which at least one multi-claim is referenced (multi-multi-claim format). [Explanation of Symbols]

[0125] 10 Algae culture device 12 Algae cultivation system 15 Manipulator 16 Robots 17 Harvest Tanks 18 Recovery vehicles 19 Material Tanks 20 culture cases 21 Translucent plate 22 Bottom plate 23 Heat transfer plate 24 Side wall 25 Exterior frame 26 Hanging equipment 27 Top plate 32 Cooling room 35 Perfusion device 36 Irrigation tube 38 Vibration device 40 Algae Culture Bags 41 Supply pipe 42 connection sockets 45 sensors 46 Cameras 47 Water container 48 pumps 50 Control device (computer) 51 Control Unit 52 Main memory 53 Auxiliary storage device 54 Communications Department 55 Display section 56 Input section 65 Log DB 70 Buildings 80 servers 81 Control Unit 82 Main storage 83 Auxiliary storage device 84 Communications Department 89 Reading Unit 90 Server Computers 96 Portable recording media 97 Programs 98 Semiconductor memory

Claims

1. The side of a cylindrical algae culture bag, in which algae are being cultivated inside, is photographed from the outside of the algae culture bag. Based on the captured images, the attached material on the inner surface of the algae culture bag is detected. Algae culture method.

2. The aforementioned algae culture bag is positioned such that the first end is lower than the second end. The image above is a photograph of the side of the first end of the algae culture bag. The method for cultivating algae according to claim 1.

3. A heat transfer plate is placed with its first surface in close contact with the side of the aforementioned algae culture bag. A water container is positioned in close contact with the second surface of the heat transfer plate. The method for cultivating algae according to claim 1.

4. Computers The aforementioned image was obtained, Based on the acquired image, it is determined whether the amount of the attached substance is greater than a predetermined threshold. A notification will be sent if the number is determined to be high. The method for cultivating algae according to claim 1.

5. The aforementioned notification includes information relating to the aforementioned image. The method for cultivating algae according to claim 4.

6. Computers Determine the level of adhesion of the aforementioned deposits, Send a notification containing information about the determined adhesion level. The method for cultivating algae according to claim 1.

7. Based on the aforementioned notification, a cleaning operation is performed that involves vibrating the surface of the algae culture bag. A method for cultivating algae according to any one of claims 4 to 6.

8. The cleaning operation is carried out by the worker applying a vibrating device to the surface of the algae culture bag. The method for cultivating algae according to claim 7.

9. The vibration device is an ultrasonic vibration device. The method for cultivating algae according to claim 8.

10. The person in charge of the work took a photograph of the algae culture bag after the cleaning work was completed. The aforementioned computer, The images taken by the aforementioned worker are recorded in association with the date and time the images were taken. The method for cultivating algae according to claim 8.

11. The cleaning operation is performed by an autonomous robot applying a vibrating device to the surface of the algae culture bag. The method for cultivating algae according to claim 7.

12. Algae are cultured inside a cylindrical algae culture bag. Computers Image data is obtained by photographing the algae culture bag, which is currently being cultured, from the outside of the algae culture bag. Based on the aforementioned image data, the deposits attached to the inner surface of the algae culture bag are detected. Send a notification containing information about the detected deposits. Based on the aforementioned notification, a cleaning operation is performed by vibrating the surface of the algae culture bag. Remove a portion of the cultured algae from the aforementioned algae culture bag. Algae production methods.

13. An algae cultivation system comprising an algae cultivation bag, a computer, and a camera, The aforementioned algae culture bag is It is cylindrical, Algae cultivation is carried out inside, The aforementioned computer, The camera is used to photograph the algae culture bag that is currently being cultivated. Acquire image data from the aforementioned camera, Based on the image data, the deposits attached to the inner surface of the algae culture bag are detected. Algae cultivation system.

Images