• Greenhouse environmental control method

Greenhouse environmental control is to maintain the optimal environment suitable for plant growth according to the amount of photosynthesis in day and night plant growth, and to maintain temperature, relative humidity and carbon dioxide concentration in the best state.
Greenhouses artificially installed for stable and continuous cultivation of plants have an adverse effect on crop growth as the internal temperature rises above the appropriate temperature due to the structure and characteristics of the greenhouse. There are a variety of materials to cover, and if these greenhouses are classified by cover type, there are glass greenhouses, vinyl greenhouses, and double-layered PC greenhouses.

In the equatorial tropics where there is a lot of solar radiation, you can select a double-layered PC to block solar radiation during the daytime. On the other hand, a glass greenhouse effectively transmits more sunlight to an area lacking sunlight, which is effective for plant growth and advantageous in terms of ventilation facilities.

In most developed countries, as a result of the unavoidable difficulties in the agricultural sector, the decline in productivity due to the decline of the agricultural population and aging, and the resulting decrease in income are serious.
Smart farm of greenhouse agriculture is a technology that applies ICT-based convergence technology to the control of the cultivation environment.
It is a control technology that provides an optimized environment for the type of crops to be cultivated, such as carbon dioxide, nutrient solution, temperature and humidity, airflow, and wind speed collected through a sensor.
As such a complex environmental controller develops from outdoor farming to indoor farming, it is a technology that has no choice but to be together. As it develops from outdoor farming, which relied on the natural environment, to indoor farming, it is evolving from initial facility house soil farming to hydroponic farming and smart hydroponics farming. Mechanical automation of the cultivation environment is the most important system in the development process of agriculture, and the items to be considered as the selection criteria for such a complex environment control device are as follows.

The complex environment controller is controlled by the set value.

With the current technology, most of the complex environmental controllers have a structure in which the agricultural producers need to provide the necessary data for the greenhouse environment, such as temperature, humidity, solar radiation, carbon dioxide, etc., necessary for crop growth, and the equipment operates according to the given value. In most cases, since agriculture has been dependent on the natural environment, they do not know the optimal cultivation environment for each actual crop.
When it comes to the complete smart farm stage, if you set the type of mushroom such as oyster mushroom, enoki mushroom, shiitake mushroom, etc. in the mushroom category, that is, the basic data for cultivated crops as a smart farm of the future, the artificial intelligence (AI) of the robot automatically detects the season and Based on the data suitable for the best growth conditions, the medium temperature and humidity sensor installed in the cultivation room, the atmospheric temperature and humidity CO2 sensor, the image sensor that monitors the mushroom growth process, the outdoor temperature and humidity sensor, the air quality sensor, the rainfall and snowfall sensors, etc. It is to control to meet the environmental conditions of various growers from the initial stage of growth to the stage of harvest.
These artificial intelligence (AI) robots will continue to evolve based on data, eventually producing the highest grade mushrooms and notifying the farmer at the time of harvest. In terms of automobiles, this is a stage corresponding to fully autonomous driving.

However, since the current smart farm complex environment controller must input data on cultivated crops for each growth stage, accurate data, that is, temperature, humidity, and carbon dioxide concentration at the mushroom development stage, that is, the concentration of carbon dioxide at the time of occurrence of deformed mushrooms, and size of mushroom cap Because the growth conditions of mushrooms differ depending on the environment, such as , shape, stem length and thickness, and they affect the quality, it is necessary to observe the growth status of mushrooms and revise the setting values ​​from time to time. If a smart farm is introduced without sufficient preparation, it may fail.

However, by preparing and studying the data on cultivated crops sufficiently, prepare an environment setting manual for each growth cycle that records the basic setting values ​​such as temperature, humidity, carbon dioxide, etc. according to each stage of cultivation environment, and install related equipment such as air conditioners, ventilation, humidifiers, lighting facilities, sprinklers, etc. to a complex environment. Optimal cultivation environment control is possible only when the controller fully understands and learns how the controller operates according to the sensing values ​​of various sensors installed inside and outside the cultivation house and can freely control the equipment according to the desired environment.

Selection of complex environmental control system suitable for greenhouse

As a factor in designing automation facilities for greenhouses and determining the complex environment control method, it is necessary to decide at what stage to introduce automation based on the type of greenhouse and the type of cultivated crops and the size of the greenhouse. At this time, productivity price, facility investment cost, etc. according to the characteristics of crops should be considered. A typical automated greenhouse is controlled by each opening/closing motor used when opening and closing the greenhouse. Fan, floating fan, lighting, irrigation, sprinkler and various pumps.
There are many devices to be controlled. Whether the control of these equipment is to be integrated into one unit or to be controlled in two or three divisions should be carefully discussed with the designer in consideration of the size of the greenhouse.

The larger the greenhouse, the higher the added value, and the more demanding the environmental conditions are, the more meticulous and complex relatively expensive equipment should be selected and installed.
When controlling the greenhouse environment, based on how much data is compared to generate the result value, the created data is a signal to stop the operation of only one related equipment, or whether various equipment are interlocked and operated proportionally. It will provide an environment suitable for plant growth while maintaining the state and consuming the least amount of energy.
For example, in maintaining the optimum temperature for growth in the greenhouse, the air conditioner, shading screen, ceiling window ventilation fan, and floating fan must be controlled in an integrated way according to the temperature set by the manager. Due to the low transmittance of sunlight, maintain the insulated state without opening or closing the double-glazed windows in the ceiling and side windows. The floating fan works occasionally. When the weather gets better and the sun is visible, immediately stop the heater and expect a temperature rise using sunlight. In consideration of the increase rate of the amount of sunlight above the set temperature, first, partially open the 1st and 2nd skylights and observe the temperature rise rate, gradually open the side windows and the triple skylights proportionally to maintain the temperature. However, the winter weather is difficult to predict, so the AI ​​robot is on standby at all times and in case of wind or snow, it immediately controls the triple skylight and side windows while monitoring the situation to prepare for changeable weather.

During cooling operation in summer, the sunlight necessary for photosynthesis of plants is controlled using a shading film and screen, and the indoor temperature is maintained by blocking the influx of excessive sunlight. At this time, AI compares the temperature and humidity of indoor air and outdoor air and, when it is determined that cooling using outdoor air is possible, opens the ceiling window and operates in outdoor air cooling setting mode. . After that, when the temperature rises continuously, the temperature rise is blocked by using the latent heat of evaporation of water by spraying mist and fog in the greenhouse according to the indoor air humidity and temperature value. However, cooling using the latent heat of evaporation of water is impossible during rain or on days with high humidity in the air. In this case, as the last option, cooling facilities that can solve both indoor temperature and humidity can be operated.

In this way, it will be difficult to apply the proportional control system by the best control algorithm in which the related equipment is sequentially and evenly based on the internal and external sensing values ​​based on the set temperature and humidity.
No matter how good the automation system is, when the user understands 100% of the facility’s functions and when cultivating facilities, it is smart to know the environmental values ​​necessary for growth such as set temperature, humidity, illuminance, carbon dioxide concentration, etc. Farming will be possible.
In addition, when classifying the functional level of these smart farms by stage, whether to choose a low-cost type with a rudimentary level or a high-end AI-based type with high specifications, how well prepared and ready to study the smart farm? You will need to choose a system that suits you.

Environmental monitoring sensor optimized for greenhouse environment control

Greenhouse environmental control will not be insufficient even if it starts from the measured values of the sensors.
Usually, the types of sensors used in the green house are temperature and humidity sensors, carbon dioxide sensors, illuminance sensors, soil or medium temperature and humidity sensors for measuring the environment inside the greenhouse. There are temperature and humidity sensors, solar radiation sensors, etc. Since there are many types of such sensors and their prices vary widely, it is necessary to select and install products with reliability and durability and economical efficiency so that the functions of various environmental control equipment installed in the greenhouse can be fully realized.
Even in an automated greenhouse equipped with state-of-the-art automation facilities and environmental control facilities, the basic data for all control is operated and maintained by the measured values of the sensors, so the selection of the sensor is of utmost importance.

If there is a lot of error in the measurement of the sensor, the machine is operated according to the measured value, so it is necessary to periodically check whether the measured value of the sensor is within the error range. Since it can be cumbersome, purchase a relatively high-precision portable measuring instrument before requesting an external professional calibration institute, measure the air condition around the sensor to be checked, and compare it with each other to check the accuracy. At this time, in order to check the more accurate measurement value, it is possible to compare the measurement by exchanging it with an extra sensor. After going through this process, if the error is serious, the sensor is replaced or calibrated. If it is an expensive sensor, it is calibrated and used, and the relatively inexpensive sensor such as temperature and humidity is discarded and replaced with a new one.
The start of greenhouse smart agriculture is data, and when high-quality data accumulated over a long period of time is collected and developed into big data, it will develop into unmanned smart agriculture when it leads to analysis and utilization through artificial intelligence.

  • Greenhouse Environment Solution

The importance of greenhouse

cooling in summer

The importance of greenhouse

cooling in summer

Greenhouse ventilation method

Greenhouse ventilation method